Differential diagnosis of presenile dementia on clinical grounds.

Fifty-seven patients were studied for differential diagnosis between dementias. Three rating-scales were used for identification of Alzheimer's disease (AD), Pick's disease (PD) and multi-infarct dementia (MID). Their validity was tested against verified diagnoses in 28 patients. The rating-scale of ischemic score consisting of 13 items such as abrupt onset, stepwise progression, fluctuating course, history of strokes and neurological symptoms and signs, identifies patients with MID. This can also be achieved by the two rating-scales for diagnosis of AD (12 items) and PD (9 items), which, however, can also be used for the differentiation between these two dementias. The rating-scale for diagnosis of AD contains clinical features such as early spatial disorientation, apraxia, aphasia, agnosia, logoclonia and increased muscular tension. The rating-scale for PD contains i.a. early loss of insight, early signs of disinhibition, echolalia, mutism and amimia. The results show that the differentiation between the major types of presenile dementia can be achieved by a systematic rating of the clinical features.