Multifocal hypointense cerebral lesions on gradient-echo MR are associated with chronic hypertension.

PURPOSE To investigate the basis for multifocal hypointense lesions within the brain as identified on T2*-weighted gradient-echo MR imaging in patients with no known or presumed cause of these lesions. METHODS In the first of a two-part study design, we retrospectively reviewed a case series of 38 patients whose gradient-echo MR images showed multiple hypointense lesions within the brain parenchyma. Thirty-one cases in which the cause was known or presumed (eg, head trauma or cavernous angioma) were excluded from further review. The MR studies and clinical findings of the remaining seven cases were reexamined. In the second part, using a cohort study design with respect to hypertension, we prospectively reviewed the gradient-echo images from MR studies of 65 patients and control subjects enrolled in two ongoing clinical studies, one on "possible vascular dementia" (n = 33) and the other on "possible motor neuron disorder" (n = 32). RESULTS In the first part of the study, we found seven cases with a pattern of multiple hypointense lesions involving the deep gray matter nuclei, especially the basal ganglia (n = 6) and thalamus (n = 5). In addition, involvement of the corona radiata (n = 5), brain stem (n = 4), and cerebellum (n = 3) was seen. Clinical review revealed a history of chronic hypertension in all seven patients. In the cohort study, we found three of 65 persons who had two or more focal hypointense lesions that involved the basal ganglia or thalami. Review of the clinical data showed that all three patients were being treated for hypertension; also, all three were patients from the "possible vascular dementia" group. CONCLUSIONS The MR imaging pattern of multifocal hypointense lesions within the basal ganglia, thalamus, and other deep cerebral structures is more commonly found among patients with a history of chronic hypertension than in patients without chronic hypertension.