Subcortical arteriosclerotic encephalopathy: CT spectrum and pathologic correlation

Because of recent papers suggesting that subcortical arteriosclerotic encephalopathy (SAE) (Binswanger's disease) is more common than historically assumed, this investigation was initiated to assess the frequency of SAE, to gauge the reliability of CT in making this diagnosis, and to assess the strength of the correlation between SAE and arterial hypertension. Of 202 autopsied patients in a 17-month period, 82 had undergone antemortem CT. Of these, 20 had CT findings thought to represent varying degrees of the disease spectrum of SAE. Microscopy confirmed this diagnosis in 18 cases. The pattern of diminished attenuation in the white matter was periventricular in 16 patients (marked asymmetry in one) and limited to an isolated focus somewhat removed from the ependyma in two. Among the 16 with periventricular disease, the extent of the process by CT appeared mild in nine, moderate in five, and severe only in two. There were two false positive CT diagnoses of SAE. Among a control group of 10 patients with normal white matter by CT, seven had some microscopic evidence of SAE, although it was generally less severe than in those with positive CT scans. Subcortical arteriosclerotic encephalopathy is common and can be identified in its various forms by CT with a high degree of reliability.