White matter lucencies on computed tomography, subacute arteriosclerotic encephalopathy (Binswanger's disease), and blood pressure.

Of 1,643 cranial computed tomography (CT) scans done in a primary-tertiary care private hospital over a 1-year period, 11 (0.67%) showed diffuse confluent white matter lucencies of less than 30 Hounsfield units. By retrospective analysis, at least 4 of the 11 were demented. Of these, 3 had clinical evidence of Binswanger's disease--characterized by progressive dementia, incontinence, variable pseudobulbar signs, and acute and subacute motor deficits. Two additional patients suffered only transient ischemic attacks or lacunar strokes; 2 had syncope; 1 had multiple sclerosis. The remaining patients were neurologically asymptomatic. In this small retrospective series, the severity of CT changes did not distinguish the patients with clinical Binswanger's syndrome from neurologically less symptomatic patients. Ten of the eleven patients had disordered blood pressure regulation--hypertension, labile systolic pressure, orthostatic hypotension, or a combination of these factors. The severity of CT changes correlated more clearly with blood pressure instability than with clinical encephalopathy. Asymptomatic adult patients with unexplained CT white matter hypodensity and blood pressure disorders may, however, be at risk for the development of subsequent subacute arteriosclerotic encephalopathy.