[Test battery for objective assessment and differential diagnosis in the early stage of suspected development of presenile dementia of the Alzheimer type].

The clinical diagnosis of organic brain syndromes (especially of primary degenerative dementia) in their early stages is uncertain or only tentative. We used a set of relatively simple tests to support the hypothesis that the disturbance of several operational brain functions precedes memory decline in primary degenerative dementia. Twenty-one patients with early stage, presenile onset of DAT, 14 patients with cardiovascular disease (CVD) and a questionable dementia, an age-matched control group (EC, n = 15), and a younger control group (YC, n = 16) were examined in the following tests: labyrinth learning test, tactile and visual pattern recognition, different reaction time tasks, eye-tracking, finger-tapping, alpha-EEG-blockade, photic driving, flicker fusion frequency, and interaction tasks. The test demonstrated that the patients performed more slowly for all tasks than did control subjects. The CVD patients performed better than the DAT group, but they were also significantly worse in the tests compared with healthy elder subjects. This test battery was found purposeful for early diagnosis of both primary degenerative and other forms of dementia, and may also be helpful to exclude other forms of organic brain syndromes.