The significance of cerebral white matter abnormalities 100 years after Binswanger's report. A review.

BACKGROUND Changes in the cerebral hemispheric white matter are detected with increasing frequency by CT and MRI among persons older than 60 years. The pathogenesis, clinical significance, and morphological substrate of these changes are incompletely understood. Patients who have such neuroimaging abnormalities are sometimes diagnosed with "Binswanger's disease," an eponym that has generated much confusion because of its imprecise meaning. The objectives of this study were to determine whether the term Binswanger's disease merits acceptance as a distinct clinicopathologic entity, to deduce the clinical significance of these white matter abnormalities from the analysis of appropriate publications, and to evaluate studies that correlate in vivo changes in the cerebral white matter with pathological features. SUMMARY OF REVIEW We evaluated Binswanger's original case description and, after conducting a Medline search, reviewed more than 160 publications, mostly in the English language, on the subject of white matter abnormalities detectable by currently used neuroimaging methods (ie, leukoaraiosis). CONCLUSIONS Binswanger's original description appears to be insufficient for the purpose of defining a new nosological entity. After evaluating the vaguely outlined pathological correlates described in a few of these subcortical cerebral leukoencephalopathies, we conclude that the clinical significance of leukoaraiosis remains incompletely defined. However, its frequency increases with age independent of other risk factors, and in nondemented subjects leukoaraiosis is associated with deficits in selected cognitive functions. Moreover, leukoaraiosis correlates with an increased risk for the subsequent development of strokes. We make specific suggestions for future studies that may help to clarify this topic.