Atypical reversible eclamptic encephalopathy: utility of diffusion weighted MRI and ADC values

Abstract

Sirs: The neuroradiological feature of eclampsia is reversible T2 hyperintensities on MRI in a parietal and occipital distribution. These findings imply cerebral edema, but differentiating between cytotoxic and vasogenic edema has been difficult in the past, as both appear hyperintense on T2weighted MR images [6]. Recently, diffusion weighted MRI (DWI) has shown these areas to have a high apparent diffusion coefficient value, suggestive of vasogenic edema [1, 6, 7]. We describe a patient with eclampsia who had a T2 hyperintense lesion in the right basal ganglia. The MR angiography and DWI findings implicated vasospasm-induced cytotoxic edema, but increased ADC value revealed that the nature of this lesion was vasogenic edema. About 6 months later, abnormal neuroradiological findings and her neurological deficits had completely disappeared.