Non-Alzheimer forms of cortical degeneration: frequency in clinical practice and clinical report of six cases.

Recent clinical and neuropathological studies suggest the possibility of distinguishing some forms of cortical degeneration from Alzheimer's disease. We report data on the frequency of non-Alzheimer forms of cerebral atrophy that were diagnosed on the basis of clinical criteria. Six examples of these neurological disorders are described: two patients with Lewy body disease; two patients with frontal lobe type dementia, one of whom had associated features of motor neuron disease; a patient with primary progressive aphasia; and a patient with a familial dementia that was probably an atypical form of Pick's disease.