Validity of clinical diagnosis in dementia: a prospective clinicopathological study.

With neuropathological diagnosis as the point of reference, the accuracy of clinical diagnosis was studied in a series of 58 demented patients. Alzheimer's disease and multi-infarct dementia were recognised with sensitivities and specificities exceeding 70%, whereas combined dementia as a separate group was relatively unreliably diagnosed. The value of Hachinski's Ischaemic Score in differentiating between Alzheimer's disease and vascular dementias was demonstrated. Its performance was to some extent improved by assigning new weights to the items. In a logistic regression model, fluctuating course, nocturnal confusion, and focal neurological symptoms emerged as features with the best discriminating value, and helped to diagnose correctly 89% of the Alzheimer and 71% of the vascular dementia patients.