Cerebral vascular autoregulatory dysfunction. Neuroradiologic aspects]

PURPOSE: We report the neuroimaging findings in a group of systemic disorders with a common pathophysiological pattern of derangements in cerebral vascular autoregulatory mechanism producting potentially reversible brain lesions. MATERIAL AND METHODS: We reviewed the brain CT and MR examinations of 14 patients with clinical diagnosis of vasculopathy not related to atherosclerosis or cardiogenic embolism. The patients were admitted at the onset of neurologic deficit and were affected with one of the following systemic disorders: thrombotic thrombocytopenic purpura (TTP, 6 cases), uremic encephalopathy (4 cases), eclampsia (2 cases), 1 chronic renal failure from systemic lupus erythematosus and 1 cyclosporin neurotoxicity. All patients underwent neuroimaging follow-up within 7-20 days of the onset of neurologic deficit and the start of anti-edema therapy. RESULTS: CT and MR findings were characterized by cortical-subcortical or deep brain lesions related to edema. Ten patients presented bilateral lesions, which were symmetric in 4 cases. Edema resolution was demonstrated on follow-up examinations after therapy in 4 patients (2 with eclampsia, 1 with TTP and 1 with uremic encephalopathy). The lesions showed no signs of regression in 10 patients. CONCLUSIONS: Brain lesions with a common pathogenesis from derangements in vascular autoregulatory mechanism--i.e., not due to atherosclerosis or cardiogenic embolism--should be properly and promptly recognized because they can be reversible and readily treatable.