Empty speech in Alzheimer's disease and fluent aphasia.

Fourteen measures of empty speech during a picture description task were examined in four subject groups--patients with Alzheimer's dementia, Wernicke's aphasias, anomic aphasias, and normal controls--to discover if these groups could be distinguished on the basis of their discourse. Patients with Alzheimer's dementia were distinguished from patients with Wernicke's aphasia by producing more empty phrases and conjunctions, whereas patients with Wernicke's aphasia produced more neologisms, and verbal and literal paraphasias. The demented patients shared many empty speech characteristics with patients with anomic aphasia. Naming deficits, as measured by confrontation naming tasks, did not correlate with empty discourse production. Our findings may be useful clinically for distinguishing these different patient groups.