Subcortical arteriosclerotic encephalopathy: Binswanger's disease.

Binswanger, in his 1894 dissertation on the differential diagnosis of general paresis of the insane, described a slowly progressive dementia associated with macroscopic loss of white matter. In recent years interest in Binswanger's disease was rekindled with CT demonstration of extensive white matter low densities in some patients. To define the clinical spectrum, we reviewed 22 consecutive cases in which the CT appearances suggested a diagnosis of Binswanger's disease. Two patients had focal neurological deficits at presentation, but recent anoxic or hypoglycaemic insults could not be excluded as the cause of the CT abnormalities. The 20 remaining patients were demented and showed variable combinations of corticobulbar dysfunction and gait dyspraxia. The duration of symptoms ranged from a few months to several years. Sixty per cent of this group gave a history of discrete stroke events and focal cortical and/or lacunar infarcts were a frequent CT finding. Binswanger's disease is probably due to chronic or acute-on-chronic white matter ischaemia. The association with lacunar and cortical infarctions suggests that a combination of large and small vessel disease produces diffuse ischaemia maximal in white matter watershed zones. Binswanger's disease is clinically differentiated from multi-infarct dementia by its time course.