Multiple white matter hyperdense lesions (WMLs) describes a vague general pattern that can be associated with a myriad of etiologies, some benign, some more concerning. Of course the significance of any MRI findings would directly relate to the patient’s age, presenting symptoms and background history, which aren’t mentioned in your query. For example, in a young woman presenting with peripheral nerve root symptoms and/or blurred vision and/or limb weakness with generalized fatigue, the finding would suggest demyelination plaques of multiple sclerosis. Patients with underlying liver disease may exhibit patchy WM disease as they develop hepatic encephalopathy. Cerebral WMLs, also called “leukoaraiosis,” are common neuroradiological findings in elderly people (> 60 years old), considered related to small vessel chronic ischemic changes (known as “age-related white matter lesions”). Many believe they are strongly related to poorly controlled hypertension. Even though these WMLs are common in the elderly, they are often associated with substantial disability and shouldn’t be considered a benign and silent condition, as once believed. In addition, recent studies have shown that an increasing number of WMLs leads to progressive gait dysfunction and cognitive decline. The progression of WM disease over time is a better predictor of cognitive impairment than the baseline WML burden on the initial MRI scan.