Limb apraxia and verb processing in Alzheimer's disease

Objective: The present research investigates language and praxis abilities in patients with Alzheimer's disease in order to study the relationship between these two cognitive domains. Method: The experimental evaluation of patients and control group performance was designed to permit a direct comparison of linguistic abilities (i.e., verb and noun naming and sentence comprehension) and praxic abilities (i.e., gesture execution for complex movements). Moreover, for the first time, action comprehension was explored using the Action Sequence Comprehension. Results and conclusion: Analyses of variance (ANOVAs) and correlational analyses showed that a direct relationship may exist between language impairment and apraxia in patients with Alzheimer's disease. In addition, the production and comprehension of both language and action were equally impaired in patients, providing further evidence for a spectrum of concomitant linguistic and praxis deficits in Alzheimer's disease. Finally, the ability to correctly comprehend action semantics was related more directly to verb production ability than to noun production.