Posterior reversible encephalopathy syndrome due to severe hypercalcemia

Posterior reversible encephalopathy syndrome (PRES) is a leukoencephalopathy clinically characterized by headache, altered mental status, visual loss and seizures. Neuroimaging demonstrates symmetrical posterior cortical and subcortical lesions. The exact pathophysiology is unknown but there is a strong association with immunosuppressants and hypertension. We report two cases of PRES in normotensive patients with severe hypercalcemia as the only identifiable cause. Possible pathophysiological mechanisms are discussed.