Progressive aphasia without dementia: two cases with focal spongiform degeneration.

Two patients with the syndrome of progressive aphasia without evidence of generalized dementia underwent postmortem neuropathological examinations. In both patients, characteristic changes of Alzheimer's disease, Pick's disease, or Creutzfeldt-Jakob disease were absent. Both patients showed a focal spongiform change involving primarily layer 2 of the left inferior frontal gyrus (and temporal cortex in Patient 1) and a mild astrocytosis in layer 2 and deeper cortical layers. This focal, spongiform cortical degeneration in patients with progressive aphasia does not appear to duplicate any known central nervous system degenerative disease.