Progression of illness in the differential diagnosis of primary dementia.

The diagnostic utility of determinations of insidious or stepwise progression of illness was examined in 124 geriatric inpatients with primary dementia. Such determinations failed to distinguish patients with primary degenerative dementia of the Alzheimer type from those with multi-infarct dementia. Episodic behavioral complications, especially depression and delusions, in the patients with primary degenerative dementia were associated with stepwise progression. Determinations of stepwise progression were made in only six (15%) of the 40 demented patients with at least two cerebral infarctions, a finding inconsistent with current diagnostic criteria for multi-infarct dementia.