Simple cerebral atrophy of non‐Alzheimer type: A comprehensive category for non‐specific cortical degeneration

We identified 19 cases of dementia characterized by cerebral atrophy with non‐specific cortical degeneration, but without pathologic features of Alzheimer's disease or other known neurodegenerative disorders. The cases were selected by a review of 14 000 autopsies and from the clinical records of the Mayo Clinic from 1972 to 1992. Microscopically, four general topographic patterns of atrophy were identified: frontal (n=6), frontotemporal (n=4), temporal (n=3), and mesiotemporal (n=4). The characteristic microscopic findings in the atrophic cortex included neuronal loss with astrocytosis, which predominantly involved the upper cortical layers, and superficial vacuolar changes. A focal or regional accentuation of involvement with different extents and severities of change was common. Neuronal achromasia was present in seven cases. Rare to sparse ubiquitin‐positive linear structures were identified in small neurons in the second cortical layer in nine cases. Argentophilic cortical grains, predominantly in the subiculum, were detected in only three cases. Involvement of the cerebral white matter corresponded to the cortical involvement. The striatum, thalamus, or substantia nigra was affected in all cases. Hippocampal involvement was evident only in the mesiotemporal type; the prosubiculum was the most severely affected area. After analyzing similar cases which had previously been reported under diverse diagnostic terms, we propose the term ‘simple cerebral atrophy of non‐Alzheimer type’ as a tentative comprehensive category for direct correlation, encompassing a spectrum of non‐Alzheimer type dementia.