Neurological abnormalities associated with severity of dementia in Alzheimer's disease.

Abnormal findings on neurological examination were evaluated in 165 patients with a clinical diagnosis of Alzheimer's disease who attended a memory disorders clinic. Severity of dementia was measured by the Blessed Dementia Scale, and associations of abnormalities with dementia severity were evaluated using logistic regression. Presence of aphasia, apraxia, and primitive reflexes on neurological examination were strongly associated with severity, and weak associations were observed for abnormalities of muscle tone and gait. Among these associated neurological features, only aphasia and apraxia were present in mildly demented cases with sufficient frequency to suggest utility as diagnostic signs early in the course of the disease.