Abstract
Dear editor,
The National Institutes of Health Stroke Scale (NIHSS) has become a standard means of assessing neurological impairment following stroke (1,2). The object naming component uses line drawings of a key, chair, glove, feather, hammock and cactuses to detect nominative aphasia. It is acknowledged that many people struggle to recognize some items.
So many of our patients, although English-speaking like the original American derivation population, have difficulties with some items that we decided to perform a study to determine the generalizability of the test and to develop strategies to improve test performance.
One hundred twenty-five nonaphasic, cognitively intact volunteers were shown each of the line drawings in turn and asked to name them. They were then shown pictures of three further objects: an elephant, an umbrella, and a tractor. Proportion of incorrect answers was recorded. Participants were then shown photographs of the same objects to see if this improved recognition or made recognition easier.
Proportions of correct identifications for each item were as follows: chair, 124 subjects (99%); key, 99%; glove, 94%; feather, 85%; cactuses, 83%; hammock, 82%; tractor, 98%; umbrella, 99%; and elephant, 99%. Subjects ⩾70 years were less likely to identify the feather [9/33 (27·3%) vs. 10/92 (10·9%), P = 0·02], the cactuses (11/33 (33·3%) vs. 10/92 (10·9%), P = 0·003], and the hammock [10/33 (30·3%) vs. 12/92 (13·0%), P = 0·025]. Women were more likely to miss the feather [5/66 (7·6%) vs. 14/59 (23·7%), P = 0·02] and cactuses [7/66 (10·6%) vs. 14/59 (23·7%), P = 0·05]. Half of women >70 years (9/18) failed to identify the cactuses. Subjects reported finding recognition from photographs easier, but differences in rate of recognition were not significant.
Several translations of the NIHSS, including the Italian, Chinese, Hindi, and Portuguese versions, have changed items in the object recognition test to more familiar objects. In our English-speaking population, substitution of more familiar objects also improved performance in the test, and this should be considered in other populations.