[Comparative age-related clinical characteristics of the initial stage in the course of Alzheimer's disease].

The relation of progressive course of Alzheimer's disease with the age of its onset was established by a retrospective analysis of the psychopathological structure and initial signs of the disease. The overall duration of the disease decreased as the age of its onset increased. This was mainly due to a reduced duration of the initial stage and to a lesser extent to shortening the pronounced dementia stage. Aphasia and apraxia showed different characteristics and rate of occurrence at the initial phase of the ailment. Early initial appearance of motor disorders was characteristic of the disease started before 60. In these cases the distinct cortical functions could be deteriorated in a relatively independent manner. Three major clinical types of the initial stage of the disease are described which correlated with its progression rate and the onset age.