Study of language function in Alzheimer patients using Japanese version of Western Aphasia Battery

We assessed language function in patients with Alzheimer's disease (AD) using the Japanese version of the Western Aphasia Battery. The results in 156 patients with probable AD were compared with those in 16 age-, sex-and education-matched cognitively normal aged volunteers. The mean Aphasia Quotient (AQ) was 78.9 in the patients with AD and 96.0 in the controls. The means of AQ and all subtest scores were significantly lower in the patients with AD than those in the controls, and related highly to Mini-Mental State Examination score, Alzheimer's Disease Assessment Scale score and Clinical Dementia Rating score. The features of language disturbance in AD included fluent speech, well-preserved repetition and comprehension abilities, and impaired naming, reading and writing abilities. The language disturbance was classified as anomic aphasia in 123 patients, Wernicke's aphasia in 14 patients, transcortical sensory aphasia in 11 patients and conduction aphasia in 2 patients. The language disturbance in 6 patients did not fit into any classic categories of aphasia.