Atypical Variant of Posterior Reversible Encephalopathy Syndrome in the Setting of Renovascular Hypertension: Case Report and Review of Literature.

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiologic syndrome resulting in subcortical vasogenic edema appreciated on T2/fluid-attenuated inversion recovery (FLAIR) sequence of magnetic resonance imaging (MRI). PRES classically involves bilateral parieto-occipital lobes and is usually reversible. Atypical variant of PRES includes the involvement of brainstem, basal ganglia, thalami, or periventricular white matter. We report an unusual case of PRES with isolated brainstem involvement with periventricular white matter changes in a patient with renovascular hypertension from unilateral renal artery stenosis. To our knowledge, this is the first case of secondary hypertension from renal artery stenosis resulting in the atypical variant of PRES.