[Psychometric speech studies in Alzheimer's dementia with the Aachen aphasia test]

Dementias of the Alzheimer type seem to be frequently accompanied by language disturbances. These may represent a feature which can be of help in distinguishing them from other types of dementias. We used the Aachen aphasia test in 32 patients suffering from Alzheimer dementia according to research criteria, and a mixed sample of 35 patients suffering from other dementias. From these 2 groups 2 subsamples of 21 patients each were gathered which were comparable with regard to age, disease onset, level of education, verbal intelligence and severity of senility. Nevertheless it was possible to distinguish the groups to a certain degree on grounds of psychometric language criteria alone. Alzheimer patients were more severely handicapped communicatively, less dysarthric, produced more automatisms and discretely more phonemic paraphasias with fluent speech which was sometimes paragrammatic. A relatively better level of repetition compared to the Token test and written language was fairly specific. A computer-assisted classification yielded language disturbances similar to Wernicke's aphasia more often than with non-Alzheimer dementias. We found no Alzheimer patients with a Broca's type of language disorder, while amnestic and global types were bound to the level of overall impairment to a certain degree. The significance of these results with regard to the use of psychometric language test in the dementias, particularly Alzheimer's dementia, and to differential diagnostic considerations are reviewed briefly.