Sensory Stimulation for Patients With Disorders of Consciousness Following a Traumatic Brain Injury (June 2013–October 2020)

Full Systematic Review Question

This systematic review addressed the question “What is the evidence for the effectiveness of interventions to improve arousal and awareness for people in a disordered state of consciousness post TBI?

Current Theme Reported

The main theme of the article included in this systematic review brief is sensory stimulation.

Clinical Scenario

More patients are surviving a traumatic brain injury (TBI) because of improvements in early resuscitation, interventions, and rehabilitation (Claassen et al., 2021). Increased survival is evident for patients with disorders of consciousness (DoC) following a severe TBI. DoC diagnoses include comatose, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state (MCS). Neurobehavioral function outcome measures may include items that capture whether a patient has emerged from MCS. Recent practice guidelines recommend practitioners use standardized neurobehavioral assessment measures to improve diagnostic accuracy for disordered states of consciousness, identify trends in the patient’s recovery trajectory, and have effective rehabilitation care (Giacino et al., 2018). Evidence demonstrates that patients can experience meaningful functional recovery 5- and 10-yr postinjury (Hammond et al., 2019; Whyte et al., 2013). We provide the current evidence about interventions that can be provided by occupational therapy practitioners as part of treatment plans for adults with DoC. This systematic review brief focuses on sensory stimulation interventions.

Summary of Key Findings

There are 14 studies that met the criteria for inclusion in this systematic review using a sensory stimulation intervention (Table 1). The 14 sensory stimulation intervention studies were delineated into two subthemes, those that used multimodal or unimodal sensory stimulation procedures. Eight studies using multimodal sensory stimulation were included. The intervention was multimodal when more than one of the senses (visual, auditory, tactile, olfactory, gustation, vestibular, and/or proprioception stimulation) was being addressed by the intervention. Six studies using unimodal sensory stimulation were included. The intervention was unimodal when the intervention focused on one of the senses. The levels of evidence used in this review are from Oxford Centre for Evidence-Based Medicine (2009).

Bottom Line for Occupational Therapy Practice

Overall, occupational therapy practitioners can use multimodal or unimodal auditory sensory stimulation to facilitate arousal and awareness in patients with DoC.

Multimodal Sensory Stimulation

Interventions that provide patients with a rich sensory experience may use a variety of contextualized stimulation to improve consciousness and have been found to support recovery of those with DoC. The eight studies using multimodal sensory stimulation highlight several principles occupational therapy practitioners should incorporate as part of their practice. First, though there is not a singular, established protocol for providing multimodal sensory interventions, the interventions included target multiple sensory systems (e.g., visual, auditory, tactile, olfactory, gustation, vestibular, and proprioception) and were completed several times per day. Occupational therapy practitioners should consider the high dosage and frequency when incorporating a multimodal sensory program into a patient’s plan of care. Additional research is needed to determine optimal timing, such as when to initiate the interventions as well as dosing and frequency recommendations. Second, five of the eight studies used sensory stimuli that were salient and meaningful (i.e., information, objects, smells, and/or experiences) to the patient. Occupational therapy practitioners should gather salient and meaningful information when conducting the patient’s occupational profile so that interventions include the patient’s preferences. Third, interventions provided by familiar family members or friends were more effective in four of the eight studies compared with interventions provided by hospital staff/nonfamiliar people. Occupational therapy practitioners should involve familiar people, family members, and care partners as key components of a patient’s plan of care. These interventions could be provided within a scheduled therapy session or as part of a home program, as the studies also indicated that a higher frequency was important. Through education and guidance, occupational therapy practitioners can work with family members to ensure they feel comfortable and capable of providing multimodal sensory opportunities to patients with DoC. Lastly, the multimodal sensory programs studied were not harmful to the patients and demonstrated positive outcomes based on standardized assessments of consciousness.

Unimodal Auditory Sensory Stimulation

The six studies using unimodal auditory stimulation were found to facilitate the patient’s arousal and awareness. Occupational therapy practitioners should incorporate unimodal auditory sensory stimulation in their intervention plan. There was moderate strength of evidence for practitioners to include familiar voices telling structured stories. Occupational therapy practitioners should work with the family and/or care partners to gather specific stories that can be structured and delivered by a familiar person. Low strength of evidence supports incorporating familiar voices telling unstructured content, familiar music, and/or verbal orientation. This does not mean these intervention strategies should not be adopted, as they still produced improvement but rather, occupational therapy needs more evidence to substantiate these findings. Occupational therapy practitioners should complete an occupational profile that gathers the patient’s preferences and personally meaningful content to incorporate during interventions.

It is important to highlight that five of the six studies occurred with patients who demonstrated stable vital signs in the intensive care unit. One study included participants up to 1-yr postinjury. Occupational therapy practitioners should consider incorporating these intervention strategies as early as 72 hr postinjury.