'Leuko-Araiosis' and Dementia

To the Editor.  —We read with great interest the series of articles on "leuko-araiosis" and dementia recently published in the Archives.^1-6 Our own investigations on incidental lesions noted on magnetic resonance imaging (MRI) of the brain were published recently.^7,8 We wish to reconcile our own findings with those of Hachinski et al, and comment on the choice of the term "leuko-araiosis."Using MRI as the primary diagnostic modality, Awad et al⁷ studied the incidence, severity, and clinical correlates of incidental subcortical parenchymal foci of increased signal intensity in 240 consecutive patients undergoing MRI at a single institution. Lesions also visualized on computed tomography (CT) and cases with known or suspected demyelinating disease or recent brain trauma were excluded. Age, hypertension, and previous brain ischemia significantly and independently correlated with incidental MRI lesions. In an accompanying article, the postmortem pathologic correlates of such lesions were studied.⁸ There