Walking difficulties in patients with Alzheimer's disease might originate from gait apraxia.

OBJECTIVES To investigate whether gait apraxia is a possible cause for some of the walking abnormalities shown by patients with Alzheimer's disease. METHODS 60 patients with Alzheimer's disease, selected as being free from overt extrapyramidal impairment or other potential causes of walking deficits, were assessed with a new test evaluating aspects of walking and related movements. Norms for this test were collected from a sample of 182 healthy volunteers. RESULTS 40% of the Alzheimer group performed below the cut off score on this test, and half performed poorly. Performance of the Alzheimer group in the walking skills test correlated highly with scores in a test assessing limb apraxia and with dementia severity. CONCLUSIONS Gait apraxia may be the cause of walking disorders found in a subgroup of patients with Alzheimer's disease. Its detection is made easier by the use of a standardised test, but still relies heavily on the exclusion of other causes of walking deficits. It is a recognisable and independent form of apraxia.