Headache Classification Committee of the International Headache Society (IHS) The International Classification of Headache Disorders,3rd edition

Primary or secondary headache or both?

Three rules apply to migraine-like headache, according to circumstances.

When a new headache with the characteristics of migraine occurs for the first time in close temporal relation to another disorder known to cause headache, or fulfils other criteria for causation by that disorder, the new headache is coded as a secondary headache attributed to the causative disorder.

Previously used terms:

Common migraine; hemicrania simplex.

Description:

Recurrent headache disorder manifesting in attacks lasting 4–72 hours. Typical characteristics of the headache are unilateral location, pulsating quality, moderate or severe intensity, aggravation by routine physical activity and association with nausea and/or photophobia and phonophobia.

Diagnostic criteria:

At least five attacks¹ fulfilling criteria B–D

Notes:

One or a few migraine attacks may be difficult to distinguish from symptomatic migraine-like attacks. Furthermore, the nature of a single or a few attacks may be difficult to understand. Therefore, at least five attacks are required. Individuals who otherwise meet criteria for 1.1 Migraine without aura but have had fewer than five attacks should be coded 1.5.1 Probable migraine without aura.

Comments:

Migraine headache in children and adolescents (aged under 18 years) is more often bilateral than is the case in adults; unilateral pain usually emerges in late adolescence or early adult life. Migraine headache is usually frontotemporal. Occipital headache in children is rare and calls for diagnostic caution. A subset of otherwise typical patients have facial location of pain, which is called ‘facial migraine’ in the literature; there is no evidence that these patients form a separate subgroup of migraine patients.

Prodromal symptoms may begin hours or a day or two before the other symptoms of a migraine attack without aura. They include various combinations of fatigue, difficulty in concentrating, neck stiffness, sensitivity to light and/or sound, nausea, blurred vision, yawning and pallor. Postdromal symptoms, most commonly feeling tired or weary, difficulty with concentration and neck stiffness, may follow resolution of the headache, persisting for up to 48 hours; these are less well studied.

Migraine attacks can be associated with cranial autonomic symptoms and symptoms of cutaneous allodynia.

In young children, photophobia and phonophobia may be inferred from their behaviour.

A minority (<10%) of women have attacks of migraine in association with the majority of their menstrual cycles; most such attacks are without aura. Attacks during menstruation tend to be longer and accompanied by more severe nausea than attacks outside the menstrual cycle. ICHD-3 offers criteria for A1.1.1 Pure menstrual migraine without aura, A1.1.2 Menstrually related migraine without aura and A1.1.3 Non-menstrual migraine without aura, but in the Appendix because of uncertainty over whether they should be regarded as separate entities. Criteria are also offered for A1.2.0.1 Pure menstrual migraine with aura, A1.2.0.2 Menstrually related migraine with aura and A1.2.0.3 Non-menstrual migraine with aura to encourage better characterization of these uncommon subforms if they are separate entities.

Very frequent migraine attacks are distinguished as 1.3 Chronic migraine. When there is associated medication overuse, both of the diagnoses 1.3 Chronic migraine and 8.2 Medication-overuse headache should be applied. 1.1 Migraine without aura is the disease most prone to accelerate with frequent use of symptomatic medication.

Regional cerebral blood flow imaging shows no changes suggestive of cortical spreading depression (CSD) during attacks of 1.1 Migraine without aura, although blood flow changes in the brainstem may occur, as may cortical changes secondary to pain activation. This contrasts with the pathognomonic spreading oligaemia of 1.2 Migraine with aura. While the bulk of the literature suggests that CSD does not occur in 1.1 Migraine without aura, some recent studies disagree. Furthermore, it has been suggested that glial waves or other cortical phenomena may be involved in 1.1 Migraine without aura. The messenger molecules nitric oxide (NO), serotonin (5-hydroxytryptamine; 5-HT) and calcitonin gene-related peptide (CGRP) are involved. While the disease was previously regarded as primarily vascular, the importance of sensitization of pain pathways, and the possibility that attacks may originate in the central nervous system, have gained increasing attention over the last decades. At the same time, the circuitry of migraine pain, the trigeminovascular system, and several aspects of its neurotransmission peripherally and in the trigeminal nucleus caudalis, central mesencephalic grey and thalamus, have been recognized. Highly receptor-specific acute medications including 5-HT_1B/D receptor agonists (triptans), 5-HT_1F receptor agonists and CGRP receptor antagonists have demonstrated efficacy in the acute treatment of migraine attacks. Because of their high receptor-specificity, their mechanisms of action provide new insight into migraine mechanisms. It is now clear that 1.1 Migraine without aura is a neurobiological disorder, while clinical as well as basic neuroscience studies continue to advance our knowledge of migraine mechanisms.

Previously used terms:

Classic or classical migraine; ophthalmic, hemiparaesthetic, hemiplegic or aphasic migraine; migraine accompagnée; complicated migraine.

Description:

Recurrent attacks, lasting minutes, of unilateral fully reversible visual, sensory or other central nervous system symptoms that usually develop gradually and are usually followed by headache and associated migraine symptoms.

Diagnostic criteria:

At least two attacks fulfilling criteria B and C

Notes:

When, for example, three symptoms occur during an aura, the acceptable maximal duration is 3×60 minutes. Motor symptoms may last up to 72 hours.

Comments:

Many patients who have migraine attacks with aura also have attacks without aura; they should be coded as both 1.2 Migraine with aura and 1.1 Migraine without aura.

Field testing has compared the diagnostic criteria for 1.2 Migraine with aura in the main body of ICHD-3 beta with those for A1.2 Migraine with aura in the Appendix. The latter performed better in distinguishing migraine with aura from transient ischaemic attacks. These are now adopted in ICHD-3, which no longer has Appendix criteria for this disorder.

The aura is the complex of neurological symptoms that occurs usually before the headache of 1.2 Migraine with aura, but it may begin after the headache phase has commenced, or continue into the headache phase.

Visual aura is the most common type of aura, occurring in over 90% of patients with 1.2 Migraine with aura, at least in some attacks. It often presents as a fortification spectrum: a zigzag figure near the point of fixation that may gradually spread right or left and assume a laterally convex shape with an angulated scintillating edge, leaving absolute or variable degrees of relative scotoma in its wake. In other cases, scotoma without positive phenomena may occur; this is often perceived as being of acute onset but, on scrutiny, usually enlarges gradually. In children and adolescents, less typical bilateral visual symptoms occur that may represent an aura. A visual aura rating scale with high specificity and sensitivity has been developed and validated.

Next in frequency are sensory disturbances, in the form of pins and needles moving slowly from the point of origin and affecting a greater or smaller part of one side of the body, face and/or tongue. Numbness may occur in its wake, but numbness may also be the only symptom.

Less frequent are speech disturbances, usually aphasic but often hard to categorize.

Systematic studies have demonstrated that many patients with visual aura occasionally have symptoms in the extremities and/or speech symptoms. Conversely, patients with symptoms in the extremities and/or speech or language symptoms almost always also experience visual aura symptoms at least during some attacks. A distinction between migraine with visual aura, migraine with hemiparaesthetic aura and migraine with speech and/or language aura is probably artificial, and therefore not recognized in this classification: they are all coded as 1.2.1 Migraine with typical aura.

When aura symptoms are multiple, they usually follow one another in succession, beginning with visual, then sensory, then aphasic; but the reverse and other orders have been noted. The accepted duration for most aura symptoms is one hour, but motor symptoms are often longer lasting.

Patients with aura symptoms arising from the brainstem are coded as 1.2.2 Migraine with brainstem aura, but they almost always have additional typical aura symptoms. When the aura includes motor weakness, the disorder should be coded as 1.2.3 Hemiplegic migraine or one of its subforms. 1.2.3 Hemiplegic migraine is classified as a separate subtype because of genetic and pathophysiological differences from 1.2.1 Migraine with typical aura. Patients with 1.2.3 Hemiplegic migraine often have brainstem symptoms in addition.

Patients often find it hard to describe their aura symptoms, in which case they should be instructed to time and record them prospectively. The clinical picture then becomes clearer. Common mistakes are incorrect reports of lateralization, of sudden rather than gradual onset and of monocular rather than homonymous visual disturbances, as well as of duration of aura and mistaking sensory loss for weakness. After an initial consultation, use of an aura diary may clarify the diagnosis.

Migraine aura is sometimes associated with a headache that does not fulfil criteria for 1.1 Migraine without aura, but this is still regarded as a migraine headache because of its relation to the aura. In other cases, migraine aura may occur without headache.

Before or simultaneously with the onset of aura symptoms, regional cerebral blood flow is decreased in the cortex corresponding to the clinically affected area and often over a wider area. Blood flow reduction usually starts posteriorly and spreads anteriorly, and is usually above the ischaemic threshold. After one to several hours, gradual transition into hyperaemia occurs in the same region. Cortical spreading depression of Leão is the likely underlying mechanism.

The previously defined syndromes, migraine with prolonged aura and migraine with acute-onset aura, have been abandoned. It is not rare for aura to last more than one hour but, in most such cases, patients have at least two of the other characteristics of criterion C. Even when most of a patient’s attacks do not fulfil criterion C, it is usual that other attacks fulfil criteria for one of the recognized subtypes or subforms of 1.2 Migraine with aura, and this should be the diagnosis. The few other cases should be coded to 1.5.2 Probable migraine with aura, specifying the atypical feature (prolonged aura or acute-onset aura) in parenthesis. The diagnosis is usually evident after a careful history alone, although there are rare secondary mimics including carotid dissection, arteriovenous malformation and seizure.

Prodromal symptoms may begin hours or a day or two before the other symptoms of a migraine attack with aura. They include various combinations of fatigue, difficulty in concentrating, neck stiffness, sensitivity to light and/or sound, nausea, blurred vision, yawning and pallor. The term ‘prodrome’, which has replaced ‘premonitory phase’ or ‘premonitory symptoms’, does not include aura. Postdromal symptoms, most commonly feeling tired or weary, difficulty with concentration and neck stiffness, may follow resolution of the headache, persisting for up to 48 hours; these are less well studied.

1.2.1 Migraine with typical aura

Description:

Migraine with aura, in which aura consists of visual and/or sensory and/or speech/language symptoms, but no motor weakness, and is characterized by gradual development, duration of each symptom no longer than one hour, a mix of positive and negative features and complete reversibility.

Diagnostic criteria:

Attacks fulfilling criteria for 1.2 Migraine with aura and criterion B below

1.2.1.1 Typical aura with headache

1.2.2 Migraine with brainstem aura

Previously used terms:

Basilar artery migraine; basilar migraine; basilar-type migraine.

Description:

Migraine with aura symptoms clearly originating from the brainstem, but no motor weakness.

Diagnostic criteria:

Attacks fulfilling criteria for 1.2 Migraine with aura and criterion B below

Notes:

Dysarthria should be distinguished from aphasia.

Comments:

Originally the terms basilar artery migraine or basilar migraine were used but, since involvement of the basilar artery is unlikely, the term migraine with brainstem aura is preferred.

There are typical aura symptoms in addition to the brainstem symptoms during most attacks. Many patients who have attacks with brainstem aura also report other attacks with typical aura and should be coded for both 1.2.1 Migraine with typical aura and 1.2.2 Migraine with brainstem aura.

Many of the symptoms listed under criterion B1 may occur with anxiety and hyperventilation, and are therefore subject to misinterpretation.

1.2.3 Hemiplegic¹ migraine

Description:

Migraine with aura including motor weakness.

Diagnostic criteria:

Attacks fulfilling criteria for 1.2 Migraine with aura and criterion B below

Notes:

The term plegic means paralysis in most languages, but most attacks are characterized by motor weakness.

Comment:

It may be difficult to distinguish weakness from sensory loss.

1.2.4 Retinal migraine

Description:

Repeated attacks of monocular visual disturbance, including scintillations, scotomata or blindness, associated with migraine headache.

Diagnostic criteria:

Attacks fulfilling criteria for 1.2 Migraine with aura and criterion B below

Comments:

Some patients who complain of monocular visual disturbance in fact have hemianopia. Some cases without headache have been reported, but migraine as the underlying aetiology cannot be ascertained.

1.2.4 Retinal migraine is an extremely rare cause of transient monocular visual loss. Cases of permanent monocular visual loss associated with migraine have been described. Appropriate investigations are required to exclude other causes of transient monocular blindness.

Description:

Headache occurring on 15 or more days/month for more than three months, which, on at least eight days/month, has the features of migraine headache.

Diagnostic criteria:

Headache (migraine-like or tension-type-like¹) on ≥15 days/month for >3 months, and fulfilling criteria B and C

Notes:

The reason for singling out 1.3 Chronic migraine from types of episodic migraine is that it is impossible to distinguish the individual episodes of headache in patients with such frequent or continuous headaches. In fact, the characteristics of the headache may change not only from day to day but even within the same day. Such patients are extremely difficult to keep medication-free in order to observe the natural history of the headache. In this situation, attacks with and those without aura are both counted, as are both migraine-like and tension-type-like headaches (but not secondary headaches).

Comment:

Code separately for both the migraine type, subtype or subform and for the complication.

1.4.1 Status migrainosus

Description:

A debilitating migraine attack lasting for more than 72 hours.

Diagnostic criteria:

A headache attack fulfilling criteria B and C

Notes:

Remissions of up to 12 hours due to medication or sleep are accepted.

Comment:

Headache with the features of 1.4.1 Status migrainosus may often be caused by medication overuse. When headache in these circumstances meets the criteria for 8.2 Medication-overuse headache, code for this disorder and the relevant type or subtype of migraine but not for 1.4.1 Status migrainosus. When overuse of medication is of shorter duration than three months, code for the appropriate migraine type or subtype(s) only.

1.4.2 Persistent aura without infarction

Description:

Aura symptoms persisting for one week or more without evidence of infarction on neuroimaging.

Diagnostic criteria:

Aura fulfilling criterion B

Comments:

Persistent aura symptoms are rare but well documented. They are often bilateral and may last for months or years. The one-week minimum in criterion B is based on the opinion of experts and should be formally studied.

Diagnostic work-up must distinguish 1.4.2 Persistent aura without infarction from 1.4.3 Migrainous infarction, and exclude symptomatic aura due to cerebral infarction of other causes. Attacks with prolonged aura lasting less than one week and not fulfilling criteria for 1.2.1 Migraine with typical aura are coded 1.5.2 Probable migraine with aura.

1.4.3 Migrainous infarction

Description:

One or more migraine aura symptoms occurring in association with an ischaemic brain lesion in the appropriate territory demonstrated by neuroimaging, with onset during the course of a typical migraine with aura attack.

Diagnostic criteria:

A migraine attack fulfilling criteria B and C

Note:

There may be additional symptoms attributable to the infarction.

Comments:

Ischaemic stroke in a migraine sufferer may be categorized as cerebral infarction of other cause coexisting with 1. Migraine, cerebral infarction of other cause presenting with symptoms resembling 1.2 Migraine with aura, or cerebral infarction occurring during the course of a typical attack of 1.2 Migraine with aura. Only the last fulfils criteria for 1.4.3 Migrainous infarction.

1.4.3 Migrainous infarction mostly occurs in the posterior circulation and in younger women.

A twofold increased risk of ischaemic stroke in patients with 1.2 Migraine with aura has been demonstrated in several population-based studies. However, it should be noted that these infarctions are not migrainous infarctions. The mechanisms of the increased risk of ischaemic stroke in migraine sufferers remain unclear; likewise, the relationship between increased risk and frequency of aura and the nature of aura symptoms denoting the increase in risk are unknown. Most studies have shown a lack of association between 1.1 Migraine without aura and ischaemic stroke.

1.4.4 Migraine aura-triggered seizure

Description:

A seizure triggered by an attack of migraine with aura.

Diagnostic criteria:

A seizure fulfilling diagnostic criteria for one type of epileptic attack, and criterion B below

Comment:

Migraine and epilepsy are prototypical examples of paroxysmal brain disorders. While migraine-like headaches are quite frequently seen in the epileptic post-ictal period, sometimes a seizure occurs during or following a migraine attack. This phenomenon, sometimes referred to as migralepsy, is a rare event, originally described in patients with 1.2 Migraine with aura. Evidence of an association with 1.1 Migraine without aura is lacking.

Previously used term:

Migrainous disorder.

Coded elsewhere:

Migraine-like headache secondary to another disorder (symptomatic migraine) is coded according to that disorder.

Description:

Migraine-like attacks missing one of the features required to fulfil all criteria for a type or subtype of migraine coded above, and not fulfilling criteria for another headache disorder.

Diagnostic criteria:

Attacks fulfilling all but one of criteria A–D for 1.1 Migraine without aura, or all but one of criteria A–C for 1.2 Migraine with aura

Comment:

In making a headache diagnosis, attacks that fulfil criteria for both 2. Tension-type headache and 1.5 Probable migraine are coded as the former in accordance with the general rule that a definite diagnosis always trumps a probable diagnosis. However, in patients who already have a migraine diagnosis, and where the issue is to count the number of attacks they are having (e.g. as an outcome measure in a drug trial), attacks fulfilling criteria for 1.5 Probable migraine should be counted as migraine. The reason for this is that mild migraine attacks, or attacks treated early, often do not achieve all characteristics necessary for a migraine attack diagnosis but nevertheless respond to specific migraine treatments.

1.5.1 Probable migraine without aura

Diagnostic criteria:

Attacks fulfilling all but one of criteria A–D for 1.1 Migraine without aura

1.5.2 Probable migraine with aura

Diagnostic criteria:

Attacks fulfilling all but one of criteria A–C for 1.2 Migraine with aura or any of its subtypes

Previously used terms:

Childhood periodic syndromes; periodic syndromes of childhood.

Comments:

This group of disorders occurs in patients who also have 1.1 Migraine without aura or 1.2 Migraine with aura, or who have an increased likelihood to develop either of these disorders. Although historically noted to occur in childhood, they may also occur in adults.

Additional conditions that may also occur in these patients include episodes of motion sickness and periodic sleep disorders including sleep walking, sleep talking, night terrors and bruxism.

1.6.1 Recurrent gastrointestinal disturbance

Previously used terms:

Chronic abdominal pain; functional abdominal pain; functional dyspepsia; irritable bowel syndrome; functional abdominal pain syndrome.

Description:

Recurrent episodic attacks of abdominal pain and/or discomfort, nausea and/or vomiting, occurring infrequently, chronically or at predictable intervals, that may be associated with migraine.

Diagnostic criteria:

At least five attacks with distinct episodes of abdominal pain and/or discomfort and/or nausea and/or vomiting

1.6.2 Benign paroxysmal vertigo

Description:

A disorder characterized by recurrent brief attacks of vertigo, occurring without warning and resolving spontaneously, in otherwise healthy children.

Diagnostic criteria:

At least five attacks fulfilling criteria B and C

Notes:

Young children with vertigo may not be able to describe vertiginous symptoms. Parental observation of episodic periods of unsteadiness may be interpreted as vertigo in young children.

Comment:

The relationship between 1.6.2 Benign paroxysmal vertigo and A1.6.6 Vestibular migraine (see Appendix) needs to be further examined.

1.6.3 Benign paroxysmal torticollis

Description:

Recurrent episodes of head tilt to one side, perhaps with slight rotation, which remit spontaneously. The condition occurs in infants and small children, with onset in the first year.

Diagnostic criteria:

Recurrent attacks¹ in a young child, fulfilling criteria B and C

Notes:

Attacks tend to recur monthly.

Comments:

The child’s head can be returned to the neutral position during attacks: some resistance may be encountered, but can be overcome.

These observations need further validation by patient diaries, structured interviews and longitudinal data collection.

1.6.3 Benign paroxysmal torticollis may evolve into 1.6.2 Benign paroxysmal vertigo or 1.2 Migraine with aura (particularly 1.2.2 Migraine with brainstem aura), or cease without further symptoms.

Primary or secondary headache or both?

Three rules apply to tension-type-like headache, according to circumstances:

When a new headache with the characteristics of tension-type headache occurs for the first time in close temporal relation to another disorder known to cause headache, or fulfils other criteria for causation by that disorder, the new headache is coded as a secondary headache attributed to the causative disorder.

In the case of chronic tension-type headache in association with medication overuse, a close temporal relation is often difficult to establish. Both diagnoses, 2.3 Chronic tension-type headache and 8.2 Medication-overuse headache, should therefore be given in all such cases.

Description:

Infrequent episodes of headache, typically bilateral, pressing or tightening in quality and of mild to moderate intensity, lasting minutes to days. The pain does not worsen with routine physical activity and is not associated with nausea, although photophobia or phonophobia may be present.

Diagnostic criteria:

At least 10 episodes of headache occurring on <1 day/month on average (<12 days/year) and fulfilling criteria B–D

Note:

When headache fulfils criteria for both 1.5 Probable migraine and 2.1 Infrequent episodic tension-type headache, code as 2.1 Infrequent episodic tension-type headache (or as either subtype of it for which the criteria are fulfilled) under the general rule that definite diagnoses always trump probable diagnoses.

2.1.1 Infrequent episodic tension-type headache associated with pericranial tenderness

Diagnostic criteria:

Episodes fulfilling criteria for 2.1 Infrequent episodic tension-type headache

2.1.2 Infrequent episodic tension-type headache not associated with pericranial tenderness

Diagnostic criteria:

Episodes fulfilling criteria for 2.1 Infrequent episodic tension-type headache

Description:

Frequent episodes of headache, typically bilateral, pressing or tightening in quality and of mild to moderate intensity, lasting minutes to days. The pain does not worsen with routine physical activity and is not associated with nausea, although photophobia or phonophobia may be present.

Diagnostic criteria:

At least 10 episodes of headache occurring on 1–14 days/month on average for >3 months (≥12 and <180 days/year) and fulfilling criteria B–D

Note:

When headache fulfils criteria for both 1.5 Probable migraine and 2.2 Frequent episodic tension-type headache, code as 2.2 Frequent episodic tension-type headache (or as either subtype of it for which the criteria are fulfilled) under the general rule that definite diagnoses always trump probable diagnoses.

Comment:

2.2 Frequent episodic tension-type headache often coexists with 1.1 Migraine without aura. Both disorders need to be identified, preferably through use of a diagnostic headache diary, because the treatments of each differ considerably. It is important to educate patients to distinguish between these headache types if they are to select the right treatment for each while avoiding medication overuse and its adverse consequence of 8.2 Medication-overuse headache.

2.2.1 Frequent episodic tension-type headache associated with pericranial tenderness

Diagnostic criteria:

Episodes fulfilling criteria for 2.2 Frequent episodic tension-type headache

2.2.2 Frequent episodic tension-type headache not associated with pericranial tenderness

Diagnostic criteria:

Episodes fulfilling criteria for 2.2 Frequent episodic tension-type headache

Coded elsewhere:

4.10 New daily persistent headache.

Description:

A disorder evolving from frequent episodic tension-type headache, with daily or very frequent episodes of headache, typically bilateral, pressing or tightening in quality and of mild to moderate intensity, lasting hours to days, or unremitting. The pain does not worsen with routine physical activity, but may be associated with mild nausea, photophobia or phonophobia.

Diagnostic criteria:

Headache occurring on ≥15 days/month on average for >3 months (≥180 days/year), fulfilling criteria B–D

Notes:

Both 2.3 Chronic tension-type headache and 1.3 Chronic migraine require headache on 15 or more days/month. For 2.3 Chronic tension-type headache, headache must, on at least 15 days, meet criteria B–D for 2.2 Frequent episodic tension-type headache; for 1.3 Chronic migraine, headache must, on at least eight days, meet criteria B–D for 1.1 Migraine without aura. A patient can therefore fulfil all criteria for both these diagnoses; for example, by having headache on 25 days/month meeting migraine criteria on eight days and tension-type headache criteria on 17 days. In these cases, only the diagnosis 1.3 Chronic migraine should be given.

2.3.1 Chronic tension-type headache associated with pericranial tenderness

Diagnostic criteria:

Headache fulfilling criteria for 2.3 Chronic tension-type headache

2.3.2 Chronic tension-type headache not associated with pericranial tenderness

Diagnostic criteria:

Headache fulfilling criteria for 2.3 Chronic tension-type headache

Description:

Tension-type-like headache missing one of the features required to fulfil all criteria for a type or subtype of tension-type headache coded above, and not fulfilling criteria for another headache disorder.

Comment:

Patients meeting one of the sets of criteria below may also meet the criteria for 1.5.1 Probable migraine without aura. In such cases, the general rule of hierarchy applies, putting 1. Migraine and its types and subtypes before 2. Tension-type headache and its types and subtypes.

2.4.1 Probable infrequent episodic tension-type headache

Diagnostic criteria:

One or more episodes of headache fulfilling all but one of criteria A–D for 2.1 Infrequent episodic tension-type headache

2.4.2 Probable frequent episodic tension-type headache

Diagnostic criteria:

Episodes of headache fulfilling all but one of criteria A–D for 2.2 Frequent episodic tension-type headache

2.4.3 Probable chronic tension-type headache

Diagnostic criteria:

Headache fulfilling all but one of criteria A–D for 2.3 Chronic episodic tension-type headache

Primary or secondary headache or both?

Three rules apply to headache with the characteristics of a trigeminal autonomic cephalalgia (TAC), according to circumstances.

When a new headache with the characteristics of a TAC occurs for the first time in close temporal relation to another disorder known to cause headache, or fulfils other criteria for causation by that disorder, the new headache is coded as a secondary headache attributed to the causative disorder.

Previously used terms:

Ciliary neuralgia; erythromelalgia of the head; erythroprosopalgia of Bing; hemicrania angioparalytica; hemicrania neuralgiformis chronica; histaminic cephalalgia; Horton’s headache; Harris-Horton’s disease; migrainous neuralgia (of Harris); petrosal neuralgia (of Gardner); Sluder’s neuralgia; sphenopalatine neuralgia; vidian neuralgia.

Coded elsewhere:

Symptomatic cluster headache, secondary to another disorder, is coded as a secondary headache attributed to that disorder.

Description:

Attacks of severe, strictly unilateral pain which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15–180 minutes and occurring from once every other day to eight times a day. The pain is associated with ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis and/or eyelid oedema, and/or with restlessness or agitation.

Diagnostic criteria:

At least five attacks fulfilling criteria B–D

Notes:

During part, but less than half, of the active time-course of 3.1 Cluster headache, attacks may be less severe and/or of shorter or longer duration.

Comments:

Attacks occur in series lasting for weeks or months (so-called cluster periods or bouts) separated by remission periods usually lasting months or years. About 10–15% of patients have 3.1.2 Chronic cluster headache, without such remission periods. In a large series with good follow-up, one quarter of patients had only a single cluster period. Such patients meet the criteria for and should be coded as 3.1 Cluster headache.

During a cluster period in 3.1.1 Episodic cluster headache, and at any time in 3.1.2 Chronic cluster headache, attacks occur regularly and may be provoked by alcohol, histamine or nitroglycerin.

The pain of 3.1 Cluster headache is maximal orbitally, supraorbitally, temporally or in any combination of these sites, but may spread to other regions. During the worst attacks, the intensity of pain is excruciating. Patients are usually unable to lie down, and characteristically pace the floor. Pain usually recurs on the same side of the head during a single cluster period.

Age at onset is usually 20–40 years. For unknown reasons, men are afflicted three times more often than women.

Acute attacks involve activation in the region of the posterior hypothalamic grey matter. 3.1 Cluster headache may be autosomal dominant in about 5% of cases.

Some patients have been described who have both 3.1 Cluster headache and 13.1.1 Trigeminal neuralgia (sometimes referred to as cluster-tic syndrome). They should receive both diagnoses. The importance of this observation is that both conditions must be treated for the patient to become headache free.

3.1.1 Episodic cluster headache

Description:

Cluster headache attacks occurring in periods lasting from seven days to one year, separated by pain-free periods lasting at least three months.

Diagnostic criteria:

Attacks fulfilling criteria for 3.1 Cluster headache and occurring in bouts (cluster periods)

Comment:

Cluster periods usually last between two weeks and three months.

3.1.2 Chronic cluster headache

Description:

Cluster headache attacks occurring for one year or longer without remission, or with remission periods lasting less than three months.

Diagnostic criteria:

Attacks fulfilling criteria for 3.1 Cluster headache, and criterion B below

Comment:

3.1.2 Chronic cluster headache may arise de novo (previously referred to as primary chronic cluster headache), or evolve from 3.1.1 Episodic cluster headache (previously secondary chronic cluster headache). In some patients, change occurs from 3.1.2 Chronic cluster headache to 3.1.1 Episodic cluster headache.

Description:

Attacks of severe, strictly unilateral pain, which is orbital, supraorbital, temporal or in any combination of these sites, lasting 2–30 minutes and occurring several or many times a day. The attacks are usually associated with ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis and/or eyelid oedema. They respond absolutely to indomethacin.

Diagnostic criteria:

At least 20 attacks fulfilling criteria B–E

Notes:

During part, but less than half, of the active time-course of 3.2 Paroxysmal hemicrania, attacks may be less frequent.

Comment:

In contrast to cluster headache, there is no male predominance. Onset is usually in adulthood, although childhood cases are reported.

3.2.1 Episodic paroxysmal hemicrania

Description:

Attacks of paroxysmal hemicrania occurring in periods lasting from seven days to one year, separated by pain-free periods lasting at least three months.

Diagnostic criteria:

Attacks fulfilling criteria for 3.2 Paroxysmal hemicrania and occurring in bouts

3.2.2 Chronic paroxysmal hemicrania (CPH)

Description:

Attacks of paroxysmal hemicrania occurring for more than one year without remission, or with remission periods lasting less than three months.

Diagnostic criteria:

Attacks fulfilling criteria for 3.2 Paroxysmal hemicrania, and criterion B below

Comment:

Patients who fulfil criteria for both 3.2.2 Chronic paroxysmal hemicrania (CPH) and 13.1.1 Trigeminal neuralgia (sometimes referred to as CPH-tic syndrome ) should receive both diagnoses. Their recognition is important, since both disorders require treatment. The pathophysiological significance of the association is not yet clear.

Description:

Attacks of moderate or severe, strictly unilateral head pain lasting seconds to minutes, occurring at least once a day and usually associated with prominent lacrimation and redness of the ipsilateral eye.

Diagnostic criteria:

At least 20 attacks fulfilling criteria B–D

Note:

During part, but less than half, of the active time-course of 3.3 Short-lasting unilateral neuralgiform headache attacks, attacks may be less frequent.

Comments:

Longer-duration attacks are characterized by multiple stabs or a saw-tooth pain pattern.

Two subtypes of 3.3 Short-lasting unilateral neuralgiform headache attacks are recognized: 3.3.1 Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and 3.3.2 Short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). 3.3.1 SUNCT may be a subform of 3.3.2 SUNA, although this requires further study. Meanwhile, each is classified as a separate subtype, described below.

3.3.1 SUNCT and 3.3.2 SUNA can usually be triggered without a refractory period. This is in contrast to 13.1.1 Trigeminal neuralgia, which usually has a refractory period after each attack.

3.3.1 Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)

Diagnostic criteria:

Attacks fulfilling criteria for 3.3 Short-lasting unilateral neuralgiform headache attacks, and criterion B below

Comments:

The literature suggests that the most common mimic of 3.3.1 SUNCT is a lesion in the posterior fossa.

Patients have been described in whom there is overlap between 3.3.1 SUNCT and 13.1.1 Trigeminal neuralgia. Differentiation is clinically complex. Such patients should receive both diagnoses.

Patients with both 3.3.1 SUNCT and 3.1 Cluster headache have been reported; the pathophysiological significance of this overlap is yet to be determined.

3.3.2 Short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA)

Attacks fulfilling criteria for 3.3 Short-lasting unilateral neuralgiform headache attacks, and criterion B below

Description:

Persistent, strictly unilateral headache, associated with ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis and/or eyelid oedema, and/or with restlessness or agitation. The headache is absolutely sensitive to indomethacin.

Diagnostic criteria:

Unilateral headache fulfilling criteria B–D

Note:

In an adult, oral indomethacin should be used initially in a dose of at least 150 mg daily and increased if necessary up to 225 mg daily. The dose by injection is 100–200 mg. Smaller maintenance doses are often employed.

Comments:

Migrainous symptoms such as photophobia and phonophobia are often seen in 3.4 Hemicrania continua.

3.4 Hemicrania continua is included under 3. Trigeminal autonomic cephalalgias in ICHD-3 on the basis that the pain is typically unilateral, as are the cranial autonomic symptoms when present (in ICHD-II it was under 4. Other primary headache disorders).

Brain imaging studies show important overlaps between all disorders included here, notably activation in the region of the posterior hypothalamic grey. In addition, the absolute response to indomethacin of 3.4 Hemicrania continua is shared with 3.2 Paroxysmal hemicrania.

3.4.1 Hemicrania continua, remitting subtype

Description:

Hemicrania continua characterized by pain that is not continuous but is interrupted by remission periods of at least 24 hours’ duration.

Diagnostic criteria:

Headache fulfilling criteria for 3.4 Hemicrania continua, and criterion B below

Comment:

3.4.1 Hemicrania continua, remitting subtype can arise de novo or from 3.4.2 Hemicrania continua, unremitting subtype.

3.4.2 Hemicrania continua, unremitting subtype

Description:

Hemicrania continua characterized by continuous pain for at least one year, without remission periods of at least 24 hours.

Diagnostic criteria:

Headache fulfilling criteria for 3.4 Hemicrania continua, and criterion B below

Comment:

3.4.2 Hemicrania continua, unremitting subtype can arise de novo or evolve from 3.4.1 Hemicrania continua, remitting subtype. The majority of patients have the unremitting subtype from onset.

Description:

Headache attacks that are believed to be a type or subtype of 3. Trigeminal autonomic cephalalgias, but which are missing one of the features required to fulfil all criteria for any of the types and subtypes coded above, and do not fulfil all criteria for another headache disorder.

Diagnostic criteria:

Headache attacks fulfilling all but one of criteria A–D for 3.1 Cluster headache, criteria A–E for 3.2 Paroxysmal hemicrania, criteria A–D for 3.3 Short-lasting unilateral neuralgiform headache attacks or criteria A–D for 3.4 Hemicrania continua

Comment:

Patients may be coded 3.5.1 Probable cluster headache, 3.5.2 Probable paroxysmal hemicrania, 3.5.3 Probable short-lasting unilateral neuralgiform headache attacks or 3.5.4 Probable hemicrania continua. Such patients either have not had a sufficient number of typical attacks (e.g. only a first bout of cluster headache), or have had a sufficient number but fail to fulfil one of the other criteria.

Primary or secondary headache or both?

Two rules apply to 4. Other primary headache disorders, according to circumstances.

When a new headache with the characteristics of any of the disorders classified here occurs for the first time in close temporal relation to another disorder known to cause headache, or fulfils other criteria for causation by that disorder, the new headache is coded as a secondary headache attributed to the causative disorder.

Previously used terms:

Benign cough headache; Valsalva-manœuvre headache.

Description:

Headache precipitated by coughing or other Valsalva (straining) manœuvre, but not by prolonged physical exercise, in the absence of any intracranial disorder.

Diagnostic criteria:

At least two headache episodes fulfilling criteria B–D

Notes:

Headache arises moments after the cough or other stimulus.

Comments:

4.1 Primary cough headache is a rare condition, accounting for 1% or fewer of all headache patients consulting neurological clinics. However, one report found one-fifth of patients with cough seen in a chest medicine clinic had cough headache.

4.1 Primary cough headache is usually bilateral and posterior, and predominantly affects patients older than 40 years of age. There is a significant correlation between the frequency of the cough and the severity of the headache. Associated symptoms such as vertigo, nausea and sleep abnormality have been reported by up to two-thirds of patients with 4.1 Primary cough headache.

While indomethacin (50–200 mg/day) is usually effective in treating 4.1 Primary cough headache, a few symptomatic cases have been reported to respond to this treatment.

4.1.1 Probable primary cough headache

Diagnostic criteria:

Either of the following:

a single headache episode fulfilling criteria B–D

Previously used terms:

Primary exertional headache; benign exertional headache.

Coded elsewhere:

Exercise-induced migraine is coded under 1. Migraine according to its type or subtype.

Description:

Headache precipitated by any form of exercise in the absence of any intracranial disorder.

Diagnostic criteria:

At least two headache episodes fulfilling criteria B and C

Note:

Symptomatic cases occur. On first occurrence of headache with these characteristics, it is mandatory to exclude subarachnoid haemorrhage, arterial dissection and reversible cerebral vasoconstriction syndrome.

Comments:

4.2 Primary exercise headache occurs particularly in hot weather or at high altitude. Subtypes such as ‘weightlifter’s headache’ are recognized but not individually classified. Unlike 4.1 Primary cough headache, which can be triggered by short-lasting trains of efforts (i.e. Valsalva-like manœuvres), 4.2 Primary exercise headache is usually precipitated by sustained physically strenuous exercise.

Headache had a pulsating character in most respondents with exercise headache in the Vågå study (less so among adolescent sufferers, of whom almost half had headache durations of less than five minutes).

There are reports of prevention in some patients by ergotamine tartrate. Indomethacin has been found effective in the majority of the cases.

The pathophysiological mechanisms underlying 4.2 Primary exercise headache are unknown. Most investigators believe it is vascular in origin, hypothesizing that venous or arterial distension, secondary to physical exercise, is the pain-inducing mechanism. The recent finding that patients with 4.2 Primary exercise headache have a significantly higher prevalence of internal jugular venous valve incompetence (70% compared with 20% of controls) suggests that intracranial venous congestion caused by retrograde jugular venous flow may play a role in the pathophysiology of this disorder.

4.2.1 Probable primary exercise headache

Diagnostic criteria:

Either of the following:

a single headache episode fulfilling criteria B and C

Previously used terms:

Benign sex headache; benign vascular sexual headache; coital cephalalgia; coital headache; intercourse headache; orgasmic cephalalgia; orgasmic headache; sexual headache.

Coded elsewhere:

Postural headache occurring after coitus should be coded as 7.2.3 Headache attributed to spontaneous intracranial hypotension because it is most probably due to CSF leakage.

Description:

Headache precipitated by sexual activity, usually starting as a dull bilateral ache as sexual excitement increases and suddenly becoming intense at orgasm, in the absence of any intracranial disorder.

Diagnostic criteria:

At least two episodes of pain in the head and/or neck fulfilling criteria B–D

Notes:

4.3 Primary headache associated with sexual activity is not associated with disturbance of consciousness, vomiting or visual, sensory or motor symptoms, whereas symptomatic sexual headache may be. On the first onset of headache with sexual activity, it is mandatory to exclude subarachnoid haemorrhage, intra- and extracranial arterial dissection and reversible cerebral vasoconstriction syndrome (RCVS).

Comments:

Two subtypes (preorgasmic headache and orgasmic headache) were included in ICHD-I and ICHD-II, but clinical studies have since been unable to distinguish these; therefore, 4.3 Primary headache associated with sexual activity is now regarded as a single entity with variable presentation.

Recent studies have shown that up to 40% of all cases run a chronic course over more than a year.

Some patients experience only one attack of 4.3 Primary headache attributed with sexual activity during their lives; they should be diagnosed as 4.3.1 Probable primary headache associated with sexual activity. For further research on this headache type, it is recommended to include only patients with at least two attacks.

Epidemiological research has further shown that 4.3 Primary headache associated with sexual activity can occur at any sexually active age, is more prevalent in males than in females (ratios range from 1.2:1 to 3:1), occurs independently of the type of sexual activity, is not accompanied by autonomic or vegetative symptoms in most cases, is bilateral in two-thirds and unilateral in one-third of cases and is diffuse or occipitally localized in 80% of cases. Attack frequency of 4.3 Primary headache associated with sexual activity should always be related to the frequency of sexual activity.

4.3.1 Probable primary headache associated with sexual activity

Diagnostic criteria:

Either of the following:

a single headache episode fulfilling criteria B–D

Previously used term:

Benign thunderclap headache.

Coded elsewhere:

4.1 Primary cough headache, 4.2 Primary exercise headache and 4.3 Primary headache associated with sexual activity can all present as thunderclap headache. When such headache is attributed uniquely to one of these triggers, it should be coded accordingly as one of these headache types.

Description:

High-intensity headache of abrupt onset, mimicking that of ruptured cerebral aneurysm, in the absence of any intracranial pathology.

Diagnostic criteria:

Severe head pain fulfilling criteria B and C

Notes:

Thunderclap headache is frequently associated with serious vascular intracranial vascular disorders, particularly subarachnoid haemorrhage: it is mandatory to exclude this and a range of other such conditions including intracerebral haemorrhage, cerebral venous thrombosis, unruptured vascular malformation (mostly aneurysm), arterial dissection (intra- and extracranial), reversible cerebral vasoconstriction syndrome (RCVS) and pituitary apoplexy. Other organic causes of thunderclap headache are meningitis, colloid cyst of the third ventricle, spontaneous intracranial hypotension and acute sinusitis (particularly with barotrauma). 4.4 Primary thunderclap headache should be a diagnosis of last resort, reached only when all organic causes have been demonstrably excluded. This implies normal brain imaging, including the brain vessels, and/or normal CSF.

Comment:

Evidence that thunderclap headache exists as a primary disorder is poor: the search for an underlying cause should be both expedited and exhaustive.

Description:

Headache brought on by a cold stimulus applied externally to the head or ingested or inhaled.

4.5.1 Headache attributed to external application of a cold stimulus

Description:

Headache following exposure of the unprotected head to a very low environmental temperature.

Diagnostic criteria:

At least two acute headache episodes fulfilling criteria B and C

Comment:

This headache is due to external cooling of the head, such as occurs during exposure in very cold weather, when diving into cold water or when receiving cryotherapy. Some patients develop intense, short-lasting, stabbing headache midfrontally, although the pain can be unilateral and temporal, frontal or retro-orbital.

4.5.2 Headache attributed to ingestion or inhalation of a cold stimulus

Previously used terms:

Ice-cream headache; brain-freeze headache.

Description:

Short-lasting frontal or temporal pain, which may be intense, induced in susceptible people by passage of cold material (solid, liquid or gaseous) over the palate and/or posterior pharyngeal wall.

Diagnostic criteria:

At least two episodes of acute frontal or temporal headache fulfilling criteria B and C

Comments:

4.5.2 Headache attributed to ingestion or inhalation of a cold stimulus is common in the general population, especially among those with 1. Migraine. Rapid ingestion of crushed ice slurry is particularly likely to provoke this headache, but eating ice-cream even slowly can do so.

Headache is frontal or temporal, and most commonly bilateral (but may be lateralized to the side of usual migraine headache in those who have unilateral headache as part of 1. Migraine).

4.5.3 Probable cold-stimulus headache

Diagnostic criteria:

A single headache episode fulfilling criteria B and C

Comment:

Codable subforms are 4.5.3.1 Headache probably attributed to external application of a cold stimulus and 4.5.3.2 Headache probably attributed to ingestion or inhalation of a cold stimulus.

Description:

Headache resulting from sustained compression of or traction upon pericranial soft tissues.

Comment:

4.6 External-pressure headache is a primary headache disorder because compression and traction are too subtle to cause damage to the scalp; in other words, they are physiological stimuli.

4.6.1 External-compression headache

Description:

Headache resulting from sustained compression of pericranial soft tissues; for example, by a tight band around the head, hat or helmet, or goggles worn during swimming or diving, without damage to the scalp.

Diagnostic criteria:

At least two episodes of headache fulfilling criteria B–D

4.6.2 External-traction headache

Previously used term:

Ponytail headache.

Description:

Headache resulting from sustained traction on pericranial soft tissues, without damage to the scalp.

Diagnostic criteria:

At least two episodes of headache fulfilling criteria B–D

Comment:

The duration of headache varies with the severity and duration of the external traction. While headache is maximal at the site of traction, it often extends to other areas of the head.

4.6.3 Probable external-pressure headache

Diagnostic criteria:

Either of the following:

a single episode of headache fulfilling criteria B–D

Comment:

Codable subforms are 4.6.3.1 Probable external-compression headache and 4.6.3.2 Probable external-traction headache.

Previously used terms:

Ice-pick pains; jabs and jolts; needle-in-the-eye syndrome; ophthalmodynia periodica; sharp short-lived head pain.

Description:

Transient and localized stabs of pain in the head that occur spontaneously in the absence of organic disease of underlying structures or of the cranial nerves.

Diagnostic criteria:

Head pain occurring spontaneously as a single stab or series of stabs and fulfilling criteria B and C

Notes:

Studies show 80% of stabs last three seconds or less; rarely, stabs last for 10–120 seconds.

Comments:

Field testing has confirmed the validity of these diagnostic criteria for 4.7 Primary stabbing headache. They enable the diagnosis of most primary headaches characterized by stabbing pain, which were not classified in ICHD-II.

4.7 Primary stabbing headache involves extratrigeminal regions in 70% of cases. It may move from one area to another, in either the same or the opposite hemicranium: in only one-third of patients it has a fixed location. When stabs are strictly localized to one area, structural changes at this site and in the distribution of the affected cranial nerve must be excluded.

A few patients have accompanying symptoms, but not including cranial autonomic symptoms. The latter help to differentiate 4.7 Primary stabbing headache from 3.3 Short-lasting unilateral neuralgiform headache attacks.

4.7 Primary stabbing headache is more commonly experienced by people with 1. Migraine, in which cases the stabs tend to be localized to the site habitually affected by migraine headaches.

4.7.1 Probable primary stabbing headache

Diagnostic criteria:

Head pain occurring spontaneously as a single stab or series of stabs

Previously used term:

Coin-shaped headache.

Description:

Pain of highly variable duration, but often chronic, in a small circumscribed area of the scalp and in the absence of any underlying structural lesion.

Diagnostic criteria:

Continuous or intermittent head pain fulfilling criterion B

Note:

Other causes, in particular structural and dermatologic lesions, have been excluded by history, physical examination and appropriate investigations.

Comments:

The painful area may be localized in any part of the scalp, but is usually in the parietal region. Rarely, 4.8 Nummular headache is bi- or multifocal, each symptomatic area retaining all the characteristics of nummular headache.

Pain intensity is generally mild to moderate, but occasionally severe. Superimposed on the background pain, spontaneous or triggered exacerbations may occur.

Duration is highly variable: in up to 75% of published cases, the disorder has been chronic (present for longer than three months), but cases have also been described with durations of seconds, minutes, hours or days.

The affected area commonly shows variable combinations of hypaesthesia, dysaesthesia, paraesthesia, allodynia and/or tenderness.

4.8.1 Probable nummular headache

Diagnostic criteria:

Continuous or intermittent head pain fulfilling criterion B

Previously used terms:

Hypnic headache syndrome; ‘alarm clock’ headache.

Description:

Frequently recurring headache attacks developing only during sleep, causing wakening and lasting for up to four hours, without characteristic associated symptoms and not attributed to other pathology.

Diagnostic criteria:

Recurrent headache attacks fulfilling criteria B–E

Notes:

Distinction from one of the types or subtypes of 3. Trigeminal autonomic cephalalgias, especially 3.1 Cluster headache, is necessary for effective management.

Comments:

A recent study has suggested these criteria, introduced in ICHD-3 beta, are more sensitive for 4.9 Hypnic headache than those of ICHD-II.

4.9 Hypnic headache usually begins after age 50 years, but may occur in younger people.

The pain is usually mild to moderate, but severe pain is reported by one-fifth of patients. Pain is bilateral in about two-thirds of cases. Attacks usually last from 15 to 180 minutes, but longer durations have been described.

Most cases are persistent, with daily or near daily headaches, but an episodic subtype (on <15 days/month) may occur.

Although it was thought that the features of 4.9 Hypnic headache were generally tension-type-like, recent studies found patients could present with migraine-like features and some patients had nausea during attacks.

Onset of 4.9 Hypnic headache is not related to sleep stage. A recent magnetic resonance imaging (MRI) study showed grey matter volume reduction in the hypothalamus in patients with 4.9 Hypnic headache.

Lithium, caffeine, melatonin and indomethacin have been effective treatments in several reported cases.

4.9.1 Probable hypnic headache

Diagnostic criteria:

Recurrent headache attacks fulfilling criteria B and C

Previously used terms:

Chronic headache with acute onset; de novo chronic headache.

Description:

Persistent headache, daily from its onset, which is clearly remembered. The pain lacks characteristic features, and may be migraine-like or tension-type-like, or have elements of both.

Diagnostic criteria:

Persistent headache fulfilling criteria B and C

Notes:

4.10 New daily persistent headache is unique in that headache is daily from onset, and very soon unremitting, typically occurring in individuals without a prior headache history. Patients with this disorder invariably recall and can accurately describe such an onset; if they cannot do so, another diagnosis should be made. Nevertheless, patients with prior headache (1. Migraine or 2. Tension-type headache) are not excluded from this diagnosis, but they should not describe increasing headache frequency prior to its onset. Similarly, patients with prior headache should not describe exacerbation associated with or followed by medication overuse.

Comment:

4.10 New daily persistent headache has two subtypes: a self-limiting subtype that typically resolves within several months without therapy, and a refractory subtype that is resistant to aggressive treatment regimens. These are not separately coded.

4.10.1 Probable new daily persistent headache

Diagnostic criteria:

Persistent headache fulfilling criteria B and C

Notes:

Since headache is extremely prevalent, it can occur simultaneously with another disorder by chance and without a causal relation. Therefore, a secondary headache can be definitely diagnosed only when solid evidence exists from published scientific studies that the disorder specified in criterion B is capable of causing headache. Scientific evidence can come from large clinical studies observing close temporal relationships between the disorder and headache outcomes after treatment of the disorder, or from smaller studies using advanced scanning methods, blood tests or other paraclinical tests, even if these are not readily available to the diagnosing physician who will use these criteria. In other words, study methods that are not useful in routine use of the diagnostic criteria may nonetheless be useful for establishing general causal relationships as the basis of criterion B. Throughout ICHD-3, however, diagnostic criteria restrict themselves to information reasonably available to the diagnosing physician in a typical clinical situation.

Primary or secondary headache or both?

The general rules for attribution to another disorder apply to 5. Headache attributed to trauma or injury to the head and/or neck.

When a new headache occurs for the first time in close temporal relation to trauma or injury to the head and/or neck, it is coded as a secondary headache attributed to the trauma or injury. This remains true when the new headache has the characteristics of any of the primary headache disorders classified in Part One of ICHD-3.

Coded elsewhere:

Trauma due to acceleration/deceleration movements of the head, with flexion/extension of the neck, is classified as whiplash. Acute headache attributed to such trauma is coded as 5.3 Acute headache attributed to whiplash. Acute headache attributed to surgical craniotomy performed for reasons other than traumatic head injury is coded as 5.5 Acute headache attributed to craniotomy.

Description:

Headache of less than three months’ duration caused by traumatic injury to the head.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Note:

Traumatic injury to the head is defined as a structural or functional injury resulting from the action of external forces upon the head. These include impact between the head and an object, penetration of the head by a foreign body, forces generated from blasts or explosions, and other forces yet to be defined.

Comment:

The stipulation that headache must be reported to have developed within seven days is somewhat arbitrary (see ‘Introduction’ above). Compared to longer intervals, a seven-day interval yields diagnostic criteria with higher specificity for 5.1 Acute headache attributed to traumatic injury to the head (i.e. stronger evidence of causation) but a correlative loss of sensitivity. Further research is needed into whether or not a different interval might be more appropriate. In the meantime, Appendix criteria for A5.1.1.1 Delayed-onset acute headache attributed to moderate or severe traumatic injury to the head and A5.1.2.1 Delayed-onset acute headache attributed to mild traumatic injury to the head may be used when the interval between injury and headache onset is greater than seven days.

5.1.1 Acute headache attributed to moderate or severe traumatic injury to the head

Diagnostic criteria:

Headache fulfilling criteria for 5.1 Acute headache attributed to traumatic injury to the head

Note:

The duration of post-traumatic amnesia is defined as the time between head injury and resumption of normal continuous recall of events.

5.1.2 Acute headache attributed to mild traumatic injury to the head

Diagnostic criteria:

Headache fulfilling criteria for 5.1 Acute headache attributed to traumatic injury to the head

Note:

The duration of post-traumatic amnesia is defined as the time between head injury and resumption of normal continuous recall of events.

Comment:

The diagnostic criteria for mild and those for moderate or severe traumatic injury to the head allow for substantial variability in the severity of the injury classified into each category. This has led some experts to suggest inclusion of additional categories: headache attributed to very mild traumatic injury to the head and headache attributed to very severe traumatic injury to the head. There is insufficient evidence for adding these categories at present, but future studies should investigate the utility of doing so.

Coded elsewhere:

Trauma due to acceleration/deceleration movements of the head, with flexion/extension of the neck, is classified as whiplash. Persistent headache attributed to such trauma is coded as 5.4 Persistent headache attributed to whiplash. Persistent headache attributed to surgical craniotomy performed for reasons other than traumatic head injury is coded as 5.6 Persistent headache attributed to craniotomy.

Description:

Headache of more than three months’ duration caused by traumatic injury to the head.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Notes:

Traumatic injury to the head is defined as a structural or functional injury resulting from the action of external forces upon the head. These include impact between the head and an object, penetration of the head by a foreign body, forces generated from blasts or explosions, and other forces yet to be defined.

Comments:

The stipulation that headache must be reported to have developed within seven days is somewhat arbitrary (see ‘Introduction’ above). Compared to longer intervals, a seven-day interval yields diagnostic criteria with higher specificity for 5.2 Persistent headache attributed to traumatic injury to the head (i.e. stronger evidence of causation) but a correlative loss of sensitivity. Further research is needed into whether or not a different interval might be more appropriate. In the meantime, Appendix criteria for A5.2.1.1 Delayed-onset persistent headache attributed to moderate or severe traumatic injury to the head and A5.2.2.1 Delayed-onset persistent headache attributed to mild traumatic injury to the head may be used when the interval between injury and headache onset is greater than seven days.

To be consistent with ICHD-II diagnostic criteria for chronic post-traumatic headache and with the time interval used in the diagnoses of other secondary headache disorders, three months is the time interval after which headache attributed to trauma or injury to the head is considered persistent. Further research is needed to investigate whether shorter or longer intervals may be more appropriately adopted.

5.2.1 Persistent headache attributed to moderate or severe traumatic injury to the head

Diagnostic criteria:

Headache fulfilling criteria for 5.2 Persistent headache attributed to traumatic injury to the head

Note:

The duration of post-traumatic amnesia is defined as the time between head injury and resumption of normal continuous recall of events.

5.2.2 Persistent headache attributed to mild traumatic injury to the head

Diagnostic criteria:

Headache fulfilling criteria for 5.2 Persistent headache attributed to traumatic injury to the head

Note:

The duration of post-traumatic amnesia is defined as the time between head injury and resumption of normal continuous recall of events.

Description:

Headache of less than three months’ duration caused by whiplash.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Note:

Whiplash is defined as sudden and inadequately restrained acceleration/deceleration movements of the head with flexion/extension of the neck. Whiplash may occur after either high or low impact forces.

Comments:

Whiplash most commonly occurs in the context of a motor vehicle accident.

5.3 Acute headache attributed to whiplash may occur as an isolated symptom or with a constellation of other symptoms that relate to the neck, as well as somatic extracervical, neurosensory, behavioural, cognitive and/or mood symptoms. Whiplash itself may be classified according to the severity of the clinical presentation, using a scheme such as that presented by the Quebec Task Force on Whiplash-Associated Disorders.

Description:

Headache of more than three months’ duration caused by whiplash.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Notes:

Whiplash is defined as sudden and inadequately restrained acceleration/deceleration movements of the head with flexion/extension of the neck. Whiplash may occur after either high or low impact forces.

Description:

Headache of less than three months’ duration caused by surgical craniotomy.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Notes:

When the craniotomy was performed following and because of head injury, code as 5.1.1 Acute headache attributed to moderate or severe traumatic injury to the head.

Comments:

5.5 Acute headache attributed to craniotomy occurs in a substantial proportion of patients undergoing surgical craniotomy. In the majority of cases, it begins within the first few days after craniotomy and resolves within the acute postoperative period. It is more common after surgery of the skull base compared to other locations.

Although the pain of 5.5 Acute headache attributed to craniotomy is often felt maximally at the site of craniotomy, it may be more diffuse and resemble tension-type headache or migraine.

Description:

Headache of more than three months’ duration caused by surgical craniotomy.

Diagnostic criteria:

Any headache fulfilling criteria C and D

Notes:

When the craniotomy was performed following and because of head injury, code as 5.2.1 Persistent headache attributed to moderate or severe traumatic injury to the head.

Comment:

About a quarter of patients who develop 5.5 Acute headache attributed to craniotomy go on to experience 5.6 Persistent headache attributed to craniotomy.

Primary or secondary headache or both?

The general rules for attribution to another disorder apply to 6. Headache attributed to cranial and/or cervical vascular disorder.

When a new headache occurs for the first time in close temporal relation to a cranial or cervical vascular disorder, it is coded as a secondary headache attributed to that disorder. This remains true when the new headache has the characteristics of any of the primary headache disorders classified in Part One of ICHD-3. This rule applies similarly to new migraine-aura-like symptoms occurring for the first time in close temporal relation to a cranial or cervical vascular disorder.

6.1.1 Headache attributed to ischaemic stroke (cerebral infarction)

6.1.2 Headache attributed to transient ischaemic attack (TIA)

Description: Headache caused by a transient ischaemic attack (TIA) and accompanied by the sudden-onset transient focal signs of a TIA. It lasts less than 24 hours

Diagnostic criteria:

Any new headache fulfilling criterion C

Notes:

The differential diagnosis between 6.1.2 Headache attributed to transient ischaemic attack and an attack of 1.2 Migraine with aura may be particularly difficult. The mode of onset is crucial: the focal deficit is typically sudden in TIA and more frequently progressive in migrainous aura. Furthermore, positive phenomena (e.g. scintillating scotoma) are far more common in migrainous aura than in TIA, whereas negative phenomena are more usual in TIA.

Comments: A transient ischaemic attack (TIA) is a transient episode of neurological dysfunction caused by focal brain or retinal ischaemia without clinical, imaging or other evidence of acute cerebral or retinal infarction. Symptoms of a TIA typically, but not invariably, last less than one hour.

While more common with basilar- than carotid-territory TIA, headache is very rarely a prominent symptom of TIA.

Coded elsewhere:

Headache attributed to traumatic intracerebral and/or subarachnoid haemorrhage or to traumatic intracerebral, subdural or epidural haematoma is coded as 5.1.1 Acute headache attributed to moderate or severe traumatic injury to the head or 5.2.1 Persistent headache attributed to moderate or severe traumatic injury to the head.

Description:

Headache caused by non-traumatic intracranial haemorrhage, generally with sudden (even thunderclap) onset. Depending on the type of haemorrhage, it may be isolated or associated with focal neurological deficits.

6.2.1 Acute headache attributed to non-traumatic intracerebral haemorrhage

Description: New and usually acute-onset headache caused by non-traumatic intracerebral haemorrhage, associated with focal neurological signs of the intracerebral haemorrhage. It can, rarely, be the presenting and prominent feature of non-traumatic intracerebral haemorrhage.

Diagnostic criteria:

Any new headache fulfilling criteria C and D

Notes:

Through usage, the term intracerebral is taken in this context to include intracerebellar.

Comments: 6.2.1 Acute headache attributed to non-traumatic intracerebral haemorrhage is more often due to subarachnoid blood and local compression than to intracranial hypertension. It can occasionally present as thunderclap headache.

Headache is more usual and more severe in haemorrhagic than in ischaemic stroke. When occurring at stroke onset, headache is associated with a higher risk of early mortality in intracerebral haemorrhage but not in ischaemic stroke.

The headache is usually overshadowed by focal deficits or coma, but it can be the prominent early feature of some intracerebral haemorrhages, notably cerebellar haemorrhage; this may require emergency surgical decompression.

6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage (SAH)

Coded elsewhere:

Non-traumatic subarachnoid haemorrhage (SAH) is distinguished from non-traumatic convexal subarachnoid haemorrhage (cSAH). The latter disorder can present with highly variable clinical and radiological features according to its various underlying causes, which include reversible cerebral vasoconstriction syndrome (RCVS), cerebral amyloid angiopathy (CAA), endocarditis and cerebral venous thrombosis. Patients with aura-like attacks, cSAH and CAA should be coded as 6.8.4 Migraine-like aura attributed to cerebral amyloid angiopathy. Patients with headache, cSAH and RCVS should be coded as 6.7.3 Headache attributed to reversible cerebral vasoconstriction syndrome.

Description:

Headache caused by non-traumatic subarachnoid haemorrhage (SAH), typically severe and sudden in onset, peaking in seconds (thunderclap headache) or minutes. It can be the sole symptom of non-traumatic SAH.

Diagnostic criteria:

Any new headache fulfilling criteria C and D

Notes:

The three months should be counted from stabilization, spontaneously or through treatment, rather than onset of the subarachnoid haemorrhage (SAH).

Comments:

Non-traumatic subarachnoid haemorrhage (SAH) is one of the most common causes of persistent, intense and incapacitating headache of abrupt onset (thunderclap headache), and is a serious condition (mortality is 40–50%, with 10–20% of patients dying before arriving at hospital; 50% of survivors are left disabled).

6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage may nonetheless be moderate and without any associated signs. The abrupt onset is the key feature. Accordingly, any patient with headache of abrupt onset or thunderclap headache should be evaluated for SAH.

Delayed diagnosis often has a catastrophic outcome: SAH is a neurointerventional emergency. However, initial misdiagnosis occurs in one quarter to one half of patients, the most common specific misdiagnosis being migraine. The most common reasons for misdiagnosis are failure to obtain appropriate neuroimaging, or misinterpretation of it, or failure to perform lumbar puncture in cases where this is required.

After diagnosis of SAH, the next urgent step is to identify a ruptured aneurysm (80% of cases of spontaneous SAH result from ruptured saccular aneurysms). In patients who are initially misdiagnosed and in whom SAH is belatedly recognized when they present again a few days later, there is often no aneurysm and no cause identifiable for the SAH.

6.2.3 Acute headache attributed to non-traumatic acute subdural haemorrhage (ASDH)

Coded elsewhere:

Most cases of acute subdural haemorrhage occur after head trauma; headache in such cases should be coded accordingly.

Description:

Headache caused by non-traumatic acute subdural haemorrhage, typically severe and sudden, peaking in seconds (thunderclap headache) or minutes. It is usually accompanied or rapidly followed by focal signs and a decrease in consciousness.

Diagnostic criteria:

Any new headache fulfilling criteria C and D

Note:

The three months should be counted from stabilization, spontaneously or through treatment, rather than onset of the acute subdural haemorrhage.

Comments:

Non-traumatic acute subdural haemorrhage (ASDH) without other intracranial haemorrhage (‘pure ASDH’) is rare. It represents a life-threatening condition and is a neurosurgical emergency.

The bleeding may be from arterial or venous origin. Reported causes include ‘spontaneous’ cortical artery rupture, aneurysm rupture, arteriovenous malformations and dural arteriovenous fistulae, tumours or metastasis, coagulopathies, Moyamoya disease, cerebral venous thrombosis and intracranial hypotension. Isolated cases or small series have mostly been reported by neurosurgeons. Headache is described in 25–100% of cases depending on the series and the underlying cause. Isolated headache can be the presenting sign, but usually it is associated or followed by a rapid neurological deterioration.

6.2.4 Persistent headache attributed to past non-traumatic intracranial haemorrhage

Description:

Headache caused by non-traumatic intracranial haemorrhage and persisting for more than three months after the haemorrhage has stabilized.

Diagnostic criteria:

Headache previously diagnosed as 6.2.1 Acute headache attributed to non-traumatic intracerebral haemorrhage, 6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage or 6.2.3 Acute headache attributed to non-traumatic acute subdural haemorrhage and fulfilling criterion C

Comments:

A few studies have documented headaches meeting the criteria for 6.2.4 Persistent headache attributed to past non-traumatic intracranial haemorrhage. Research is needed to identify risk factors for such a persistent headache; previous history of 1. Migraine may play a role, as may anxiety/depression.

Codable subforms are 6.2.4.1 Persistent headache attributed to past non-traumatic intracerebral haemorrhage, 6.2.4.2 Persistent headache attributed to past non-traumatic subarachnoid haemorrhage and 6.2.4.3 Persistent headache attributed to past non-traumatic acute subdural haemorrhage.

Coded elsewhere:

New headache attributed to ruptured vascular malformation is coded as 6.2.1 Acute headache attributed to non-traumatic intracerebral haemorrhage, 6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage or, rarely, 6.2.3 Acute headache attributed to non-traumatic acute subdural haemorrhage.

Description:

Headache secondary to an unruptured intracranial vascular malformation (occurring without haemorrhage). Depending on the type of malformation, the headache may have a chronic course with recurrent attacks mimicking episodic primary headaches, or an acute and self-limiting course.

6.3.1 Headache attributed to unruptured saccular aneurysm

Diagnostic criteria:

Any new headache fulfilling criterion C

Note:

In particular, intracranial haemorrhage and reversible cerebral vasoconstriction syndrome have been excluded by appropriate investigations.

Comments:

Headache is reported by approximately one-fifth of patients with unruptured cerebral aneurysm, but whether this association is incidental or causal is an unresolved issue.

6.3.1 Headache attributed to unruptured saccular aneurysm usually has no specific features. Any new-onset headache can reveal a symptomatic but unruptured saccular aneurysm. A classic variety is acute IIIrd nerve palsy with retro-orbital pain and a dilated pupil, indicating an aneurysm of the posterior communicating cerebral artery or termination of the carotid artery. Such painful IIIrd nerve palsy is an emergency, signalling impending rupture or progressive enlargement of the arterial malformation.

Several retrospective studies have shown that about half of patients with an aneurysmal subarachnoid haemorrhage reported the occurrence of a sudden and severe headache within the four weeks prior to diagnosis of aneurysmal rupture. Setting aside the possibility of memory biases, this suggests these headaches are due to sudden enlargement of the arterial malformation (sentinel headache) or to mild subarachnoid haemorrhage that is not diagnosed as such (‘warning leak’). Evidence for the existence of sentinel headaches is poor. Moreover, the term ‘warning leak’ should not be used because a leak indicates a subarachnoid haemorrhage. Given that at least one in three patients with aneurysmal subarachnoid haemorrhage is initially misdiagnosed, and the risks of re-bleeding, patients with sudden severe headaches should undergo complete investigation, including cerebral imaging, CSF study and cerebral angiography (MR or CT angiography).

6.3.2 Headache attributed to arteriovenous malformation (AVM)

Diagnostic criteria:

Any headache fulfilling criterion C

Note:

In particular, intracranial haemorrhage has been excluded by appropriate investigations.

Comments:

Cases have been reported highlighting the association of arteriovenous malformation (AVM) with different types of 3. Trigeminal autonomic cephalalgias including 3.1 Cluster headache, 3.2.2 Chronic paroxysmal hemicrania and 3.3.1 Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), but these cases had atypical features. There is no good evidence of a relationship between AVM and these primary headache disorders.

1.2 Migraine with aura has been reported in up to 58% of women with AVM. A strong argument in favour of a causal relationship is the overwhelming correlation between the side of the headache, or of the aura, and the side of the AVM. There is thus a strong suggestion that AVM can cause attacks of migraine with aura (symptomatic migraine). Yet in a large AVM series, presenting features frequently included epilepsy or focal deficits with or without haemorrhage and migraine-like symptoms much more rarely.

6.3.3 Headache attributed to dural arteriovenous fistula (DAVF)

Diagnostic criteria:

Any new headache fulfilling criterion C

Note:

In particular, intracerebral haemorrhage and cerebral venous thrombosis have been excluded by appropriate investigations.

Comment:

Studies devoted to 6.3.3 Headache attributed to dural arteriovenous fistula are lacking. A painful pulsatile tinnitus can be a presenting symptom, as well as headache with features of intracranial hypertension due to decrease in venous outflow and sometimes to sinus thrombosis. Carotidocavernous fistulae may present as painful ophthalmoplegia.

6.3.4 Headache attributed to cavernous angioma

Coded elsewhere:

Headache attributed to cerebral haemorrhage or seizure secondary to cavernous angioma is coded as 6.2.1 Acute headache attributed to non-traumatic intracerebral haemorrhage or 7.6 Headache attributed to epileptic seizure.

Diagnostic criteria:

Any new headache fulfilling criterion C

Note:

In particular, intracerebral haemorrhage has been excluded by appropriate investigations.

Comments:

Cavernous angiomas are increasingly recognized on MRI. Isolated case reports suggest that some cavernous angiomas may trigger cluster headache-like, SUNCT-like or migraine-like attacks. However, there is still no good study devoted to 6.3.4 Headache attributed to cavernous angioma.

In a series of 126 symptomatic patients with cavernous angiomas and KRIT1 mutations, only 4% reported headache as a presenting symptom. On the contrary, headache is commonly reported as a consequence of cerebral haemorrhage or of seizures, which are the two main manifestations of cavernous angiomas; such headache should be coded to either of these accordingly.

6.3.5 Headache attributed to encephalotrigeminal or leptomeningeal angiomatosis (Sturge Weber syndrome)

Coded elsewhere:

Headache attributed to seizure secondary to Sturge Weber syndrome is coded as 7.6 Headache attributed to epileptic seizure.

Diagnostic criteria:

Any new headache fulfilling criterion C

Comments:

Sturge Weber syndrome occurs exclusively sporadically, resulting from a somatic mosaic mutation in the GNAQ gene (guanine nucleotide-binding protein, Q polypeptide).

6.3.5 Headache attributed to encephalotrigeminal or leptomeningeal angiomatosis (Sturge Weber syndrome) is poorly documented. More than 90% of cases of Sturge Weber syndrome have seizures, and half report post-seizure headaches, which should be coded accordingly. Isolated reports suggest that encephalotrigeminal or leptomeningeal angiomatosis may be a cause of symptomatic migraine, particularly of attacks with prolonged and/or motor auras (possibly related to chronic oligaemia).

Description:

Headache caused by and symptomatic of an inflammation of cervical, cranial and/or brain arteries. Headache may be the sole symptom of arteritis.

Diagnostic criteria:

Any new headache fulfilling criterion C

6.4.1 Headache attributed to giant cell arteritis (GCA)

Previously used term:

Headache attributed to temporal arteritis.

Description:

Headache caused by and symptomatic of giant cell arteritis (GCA). Headache may be the sole symptom of GCA, a disease most conspicuously associated with headache. The features of the headache are variable.

Diagnostic criteria:

Any new headache fulfilling criterion C

Comments:

Of all arteritides and collagen vascular diseases, giant cell arteritis (GCA) is the disease most conspicuously associated with headache, which is due to inflammation of cranial arteries, especially branches of the external carotid artery. The variability in the features of 6.4.1 Headache attributed to giant cell arteritis and in the other symptoms of GCA (polymyalgia rheumatica, jaw claudication) are such that any recent persisting headache in a patient over 60 years of age should suggest GCA and lead to appropriate investigations.

Recent repeated attacks of amaurosis fugax associated with headache are very suggestive of GCA and should prompt urgent investigations. The major risk is of blindness due to anterior ischaemic optic neuropathy, which can be prevented by immediate steroid treatment; the time interval between visual loss in one eye and in the other is usually less than one week. Patients with GCA are also at risk of cerebral ischaemic events and of dementia.

Histological diagnosis can be difficult because the temporal artery may appear uninvolved in some areas (skip lesions), pointing to the necessity of serial sectioning.

6.4.2 Headache attributed to primary angiitis of the central nervous system (PACNS)

Previously used term:

Headache attributed to isolated CNS angiitis or granulomatous CNS angiitis.

Description:

Headache caused by and symptomatic of primary angiitis of the central nervous system (PACNS). Headache is the dominant symptom of this disorder, but lacks specific features.

Diagnostic criteria:

Any new headache fulfilling criterion C

Note:

In particular, central nervous system (CNS) infection, CNS neoplasia and reversible cerebral vasoconstriction syndrome have been excluded by appropriate investigations.

Comments:

Headache is the dominant symptom in CNS angiitis (either primary or secondary). It is present in 50–80% of cases according to the diagnostic methods used, respectively angiography and histology. Nevertheless, it has no specific features and is therefore of little diagnostic value until other signs are present, such as focal deficits, seizures, altered cognition or disorders of consciousness. However, the absence of both headache and CSF pleocytosis makes CNS angiitis unlikely.

Primary angiitis of the central nervous system (PACNS) can present with angiographic findings quite similar to those of reversible cerebral vasoconstriction syndrome (RCVS), including multifocal stenosis of the intracranial arteries; recurrent thunderclap headaches should suggest a diagnosis of RCVS and not PACNS.

The pathogenesis of 6.4.2 Headache attributed to primary angiitis of the central nervous system is multifactorial: inflammation, stroke (ischaemic or haemorrhagic), raised intracranial pressure and/or subarachnoid haemorrhage.

The effect of treatment is far less dramatic than in 6.4.1 Headache attributed to giant cell arteritis. Histologically proven primary CNS angiitis remains a serious and not infrequently lethal condition.

6.4.3 Headache attributed to secondary angiitis of the central nervous system (SACNS)

Description:

Headache caused by and symptomatic of secondary angiitis of the central nervous system (SACNS). Headache is the dominant symptom of this disorder, but lacks specific features.

Diagnostic criteria:

Any new headache fulfilling criterion C

Comments:

Headache is the dominant symptom in CNS angiitis (either primary or secondary). It is present in 50–80% of cases according to the diagnostic methods used, respectively angiography and histology. Nevertheless, it has no specific features and is therefore of little diagnostic value until other signs are present such as focal deficits, seizures, altered cognition or disorders of consciousness. However, the absence of both headache and CSF pleocytosis makes CNS angiitis unlikely.

The difficulty here is twofold: (1) diagnosing CNS angiitis in a patient known to have one of the many conditions that can cause angiitis; (2) finding the underlying condition (inflammatory, infectious, malignant, toxic) in a patient presenting with CNS angiitis.

The pathogenesis of 6.4.3 Headache attributed to secondary angiitis of the central nervous system is multifactorial: inflammation, stroke (ischaemic or haemorrhagic), raised intracranial pressure and/or subarachnoid haemorrhage.

Description:

Headache and/or pain in the face and/or neck caused by non-inflammatory lesions affecting the cervical carotid and/or vertebral arteries. The pain generally has a sudden (even thunderclap) onset. It can remain isolated or be a warning symptom preceding the focal deficits of ischaemic stroke.

Diagnostic criteria:

Any new headache and/or facial or neck pain fulfilling criterion C

6.5.1 Headache or facial or neck pain attributed to cervical carotid or vertebral artery dissection

6.5.2 Post-endarterectomy headache

Description:

Headache caused by the surgical procedure of carotid endarterectomy. Pain can also involve the neck and face. It can remain isolated or be a warning symptom preceding the focal deficits of (mostly haemorrhagic) stroke.

Diagnostic criteria:

Any new headache fulfilling criterion C

Notes:

Three subforms of 6.5.2 Post-endarterectomy headache have been described, but are not separately coded:

a diffuse, mild, isolated headache occurring in the first few days after surgery

Comment:

Of the three subforms of 6.5.2 Post-endarterectomy headache, the first and most frequent (up to 60% of cases) is a benign self-limiting condition, while the second (reported in up to 38% of cases) resolves in about two weeks. The third subform is part of the rare hyperperfusion syndrome, often preceding a rise in blood pressure and the onset of seizures or neurological deficits on or about the seventh day. Urgent treatment is required, since these symptoms can herald cerebral haemorrhage.

6.5.3 Headache attributed to carotid or vertebral angioplasty or stenting

Description:

Headache caused by the endovascular procedures of cervical angioplasty and/or stenting. Pain can also involve the neck and face. It can remain isolated or be a warning symptom preceding the focal deficits of (mostly haemorrhagic) stroke.

Diagnostic criteria:

Any new headache, fulfilling criterion C

Note:

In particular, arterial dissection has been excluded by appropriate investigations.

Comments:

Carotid and vertebral angioplasty and/or stenting are performed to treat cervical artery stenosis.

In a series of 64 patients who had carotid stenting, headache occurred in one-third, usually within 10 minutes after the procedure, and was mild, ipsilateral, frontotemporal and pressing in nature; it mostly disappeared within 10 minutes. Otherwise, data on 6.5.3 Headache attributed to carotid or vertebral angioplasty or stenting remain scarce. Headache is not mentioned in large trials comparing carotid stenting and endarterectomy.

6.5.3 Headache attributed to carotid or vertebral angioplasty or stenting has been reported as part of the rare hyperperfusion syndrome.

6.6.1 Headache attributed to cerebral venous thrombosis (CVT)

Description:

Headache caused by cerebral venous thrombosis (CVT). It has no specific characteristics: it is most often diffuse, progressive and severe, but can be unilateral and sudden (even thunderclap), or mild, and sometimes is migraine-like.

Diagnostic criteria:

Any new headache, fulfilling criterion C

Comments:

Headache is by far the most frequent symptom of cerebral venous thrombosis (CVT), present in 80–90% of cases, and also the most frequent inaugural symptom.

6.6.1 Headache attributed to cerebral venous thrombosis has no specific characteristics, but most often is diffuse, progressive and severe, and associated with other signs of intracranial hypertension. It can also be unilateral and sudden, and sometimes very misleading, mimicking 1.1 Migraine without aura, 1.2 Migraine with aura, 3.1 Cluster headache, 3.4 Hemicrania continua, 4.4 Primary thunderclap headache, 7.2 Headache attributed to low cerebrospinal fluid pressure or 6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage (SAH) (CVT can be a cause of SAH).

Headache can be the only manifestation of CVT but, in over 90% of cases, it is associated with focal signs (neurological deficits or seizures) and/or signs of intracranial hypertension, subacute encephalopathy or cavernous sinus syndrome.

Given the absence of specific characteristics of 6.6.1 Headache attributed to cerebral venous thrombosis, any recent persisting headache should raise suspicion, particularly in the presence of an underlying prothrombotic condition. Diagnosis is based on neuroimaging (MRI with T2*-weighted images plus MRA, or CT scan plus CT angiography, and intra-arterial angiography in doubtful cases). Treatment should be started as early as possible and includes symptomatic treatment, heparin followed by at least six months of oral anticoagulation and, whenever indicated, treatment of the underlying cause.

6.6.2 Headache attributed to cranial venous sinus stenting

Description:

Unilateral headache caused by and on the same side as cranial venous sinus stenting.

Diagnostic criteria:

New unilateral headache, fulfilling criterion C

Note:

In particular, within-stent venous thrombosis has been excluded.

Comments:

Over the past decade, stenting of lateral sinus stenosis has been used to treat idiopathic intracranial hypertension.

Data about 6.6.2 Headache attributed to cranial venous sinus stenting are scarce. In one series of 21 patients stented for idiopathic intracranial hypertension, 10 patients exhibited ‘stent-headaches’ differing from those experienced before treatment, located at the site of the stent, in the mastoid region, and lasting about three weeks.

6.7.1 Headache attributed to an intracranial endarterial procedure

Description:

Unilateral headache caused directly by an intracranial endarterial procedure, ipsilateral to the procedure and lasting less than 24 hours.

Diagnostic criteria:

Any new headache fulfilling criterion C

Notes:

For example, angioplasty, embolization or stent placement.

6.7.2 Angiography headache

Description:

Headache caused directly by cerebral angiography.

Diagnostic criteria:

Any new headache fulfilling criterion C

Note:

There are three recognized (but not separately coded) subforms of 6.7.2 Angiography headache.

occurring during angiography, and closely related to contrast injection

Comment:

Contrast angiography is contraindicated in patients affected by any subform of 1.2.3 Hemiplegic migraine because it may trigger a life-threatening attack, with prolonged hemiplegia and coma.

6.7.3 Headache attributed to reversible cerebral vasoconstriction syndrome (RCVS)

6.7.4 Headache attributed to intracranial artery dissection

Description:

Headache caused by dissection of an intracranial artery. The pain is mostly unilateral, ipsilateral to the dissected vessel, and generally has a sudden (even thunderclap) onset. It can remain isolated or be a warning symptom preceding subarachnoid haemorrhage or stroke.

Diagnostic criteria:

Any new headache fulfilling criterion C

Comments:

Dissection can affect any intracranial artery and may induce subarachnoid haemorrhage, ischaemic infarcts, compression of adjacent structures or, less commonly, intracerebral haemorrhage. In Asians, intracranial arterial dissection is more frequent than cervical artery dissection.

Acute headache is often the presenting symptom and can be the sole symptom of this disorder.

6.8.1 Headache attributed to cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Description:

Headache recurring in attacks resembling 1.2 Migraine with aura, except for an unusual frequency of prolonged aura, caused by cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). It is associated with the other clinical features of CADASIL or, often, the first symptom of it.

Diagnostic criteria:

Recurrent attacks of migraine with typical, hemiplegic or prolonged aura, fulfilling criterion C

Note:

The diagnosis is made by screening for NOTCH3 mutations, by a simple skin biopsy with immunostaining of NOTCH3 antibodies, or with electron microscopy to assess for extracellular granular osmiophilic material (GOM) within the arterial media.

Comments:

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant disease, with some sporadic cases, involving the smooth muscle cells in the media of small arteries of the brain. It is due to mutations of the NOTCH3 gene.

CADASIL is characterized clinically by recurrent small deep infarcts, subcortical dementia, mood disturbances and, in one-third of cases, by attacks typical of 1.2 Migraine with aura except for an unusual frequency of prolonged aura. In such cases, these are usually the first symptom of the disease, appearing at a mean age of 30 years, some 15 years before ischaemic strokes and 20–30 years before death.

MRI is always abnormal, with striking white matter changes on T2-weighted images.

6.8.2 Headache attributed to mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

Description:

Headache, which is either recurrent in migraine-like attacks or a presenting symptom of stroke-like episodes, caused by and associated with the other clinical features of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS).

Diagnostic criteria:

Recurrent attacks of headache fulfilling criterion C

Comments:

Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a genetically heterogeneous mitochondrial disorder with a variable clinical phenotype, including features of central nervous system involvement (seizures, hemiparesis, hemianopia, cortical blindness, sensorineural deafness and/or episodic vomiting). Headache is common in MELAS, either as recurrent migraine-like attacks or as the presenting symptom of stroke-like episodes.

The high frequency of migraine-like attacks as part of MELAS has led to the hypothesis that mitochondrial mutations play a role in migraine with aura, but the 3243 mutation was not detected in two groups of subjects with 1.2 Migraine with aura. Other yet-undetected mutations may play a role in both migraine and ischaemic stroke, since migraine attacks, mostly with aura, also occur in other mitochondrial disorders.

6.8.3 Headache attributed to Moyamoya angiopathy (MMA)

Description:

Chronic recurrent headache, which may be migraine-like, caused by and associated with the other clinical features of Moyamoya angiopathy.

Diagnostic criteria:

Recurrent headache fulfilling criterion C

Comments:

Moyamoya angiopathy (MMA) is characterized by bilateral progressive narrowing and occlusion of the intracranial portion of the internal carotid, middle cerebral and anterior cerebral arteries. Several susceptibility genes have been identified or localized for MMA. In some other patients, MMA is associated with other conditions (sickle cell anaemia, Down syndrome and radiation therapy amongst others) and is referred to as Moyamoya syndrome.

MMA usually presents early in childhood or adolescence with ischaemic or haemorrhagic stroke that can cause acute headache. Outside of these acute vascular events, headache is highly common in both children and adults with MMA, phenotypically most commonly resembling 1.1 Migraine without aura, 1.2 Migraine with aura, 1.2.3 Hemiplegic migraine or 2. Tension-type headache; cluster headache-like attacks have been rarely reported.

Revascularization surgery has variable effects on headache in MMA, with improvement in some patients, persistence in others, and postoperative new-onset headache in another subset.

6.8.4 Migraine-like aura attributed to cerebral amyloid angiopathy (CAA)

Description

Late-onset migraine-like aura attacks without headache or with mild headache, also termed ‘amyloid spells’, caused by and associated with the other clinical features of cerebral amyloid angiopathy, often in the setting of convexal subarachnoid haemorrhage.

Diagnostic criteria:

New attacks of migraine-like aura, with or without mild headache, fulfilling criterion C

Note:

Blood-sensitive MRI sequences are important in diagnosing cerebral amyloid angiopathy, and should be performed in any patient with late-onset migraine-like aura.

Comments:

Cerebral amyloid angiopathy (CAA) is a small-vessel disorder associated with progressive amyloid deposition in the walls of cortical and leptomeningeal vessels. Sporadic forms are more common than inherited familial forms.

CAA is a major cause of lobar symptomatic intracerebral haemorrhage, transient focal neurologic episodes in the elderly and cognitive impairment. Transient focal neurological episodes include both positive migraine aura-like (spreading paraesthesias and/or positive visual phenomena) and negative TIA-like neurological symptoms, and may be caused by superficial cortical siderosis or convexal subarachnoid haemorrhage. These episodes are associated with a high early risk of symptomatic intracerebral haemorrhage.

6.8.5. Headache attributed to syndrome of retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCLSM)

Description:

Headache recurring as migraine-like attacks, mainly without aura, caused by the syndrome of retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCLSM). It may be associated with the other clinical features of RVCLSM or be the earliest clinical manifestation of it.

Diagnostic criteria:

Recurrent migraine-like attacks, with or without aura, fulfilling criterion C

Note:

Diagnosis is made by genetic testing for TREX1 mutations.

Comment:

The syndrome of retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCLSM) is an autosomal dominant systemic small-vessel disease caused by C-terminal frame-shift mutations in TREX1. It is characterized clinically by focal neurological deficits, cognitive impairment, psychiatric disturbances, seizures, various systemic manifestations and, in at least half of cases, by migraine-like attacks. Other clinical manifestations are visual impairment from vascular retinopathy, and neurological decline and premature death due to progressive enhancing cerebral white matter lesions. The clinical spectrum also includes impaired liver and kidney function, anaemia sometimes associated with gastrointestinal bleeding and hypertension. In younger patients, in whom brain MRI may be normal, the clinical manifestations include mild Raynaud’s phenomenon (54%), migraine (mainly without aura: 42%) and psychiatric disturbances (23%). The diagnosis in such cases may be suspected from family history.

6.8.6 Headache attributed to other chronic intracranial vasculopathy

Description:

Migraine-like attacks, with or without aura, caused by and occurring as part of the clinical manifestations of a genetic or non-genetic chronic intracranial vasculopathy other than those described above.

Diagnostic criteria:

Recurrent migraine-like attacks, with or without aura, fulfilling criterion C

Comments:

Recurrent migraine-like attacks have been reported as part of the clinical manifestations of the autosomal dominant hereditary infantile hemiparesis, retinal arterial tortuosity and leucoencephalopathy (HIHRATL), a condition due to COL4A1 mutations. Only a few families with this disorder have been reported. Because of the other severe manifestations, these migraine-like attacks have not been systematically investigated in HIHRATL but they appear mainly to resemble 1.2 Migraine with aura.

All of the other rare genetic and non-genetic chronic intracranial vasculopathies can, potentially, cause migraine-like attacks.

Description:

Headache caused by pituitary apoplexy, usually with sudden (even thunderclap) onset and severe intensity, and accompanied from onset or later by visual symptoms and/or hypopituitarism.

Diagnostic criteria:

Any new headache fulfilling criterion C

Comments:

The rare clinical syndrome of pituitary apoplexy is an acute, life-threatening condition. It is one of the causes of non-aneurysmal subarachnoid haemorrhage.

It is also one of the causes of thunderclap headache. Most cases occur as the first presentation of rapid enlargement of non-functioning pituitary macroadenomas due to haemorrhage and/or infarction.

MRI is more sensitive than CT scan for detecting intrasellar pathology.

6.1.1 Headache attributed to ischaemic stroke (cerebral infarction)

Ferro JM, Melo TP, Oliveira V, et al. A multivariate study of headache associated with ischemic stroke. Headache 1995; 35: 315–319.

Gorelick PB, Hier DB, Caplan LR, et al. Headache in acute cerebrovascular disease. Neurology 1986; 36: 1445–1450.

Hansen AP, Marcussen NS, Klit H, et al. Development of persistent headache following stroke: a 3-year follow-up. Cephalalgia 2015; 35: 399–409.

Lopes Azevedo L, Breder R, de A Santos DP, et al. Ischemic stroke presenting as thunderclap headache: report of two cases and review of the literature. Eur Neurol 2011; 66: 133–135.