Leukoaraiosis: From an Ancient Term to an Actual Marker of Poor Prognosis

See related article, pages 1409–1413. The term leukoaraiosis (from the Greek leuko , white, and araiosis , rarefaction) was introduced in 1986 by Hachinski, Potter and Merskey to designate bilateral and symmetrical areas in the periventricular and centrum semiovale white matter that appeared hypodense on CT scans and hyperintense on T2-weighted MRI.1,2 Leukoaraiosis was supposed to be “a neutral term, exact enough to define white-matter changes, sufficient as a description or label, and demanding enough to require precise clinical and imaging descriptions.”1,2 It was clear in Hachinski and coworkers’ proposal the aim of contrasting the tendency to immediately identify a radiological aspect with a clinical picture. At that time, changes or lesions of the white matter were recognized with increasing frequency on the brain CT scans of elderly patients,3 and some authors had begun to attribute a clinical significance to these radiological findings, particularly interpreting them as a correlate of cognitive decline. According to some, the introduction of CT had made possible the identification in vivo of subcortical arteriosclerotic encephalopathy (or Binswanger disease), a form of vascular dementia with only few cases reported on pathological grounds until the eighties.4,5 The issue became even more complex after the introduction of MRI in neurological clinical practice because it was soon apparent …