This is a double blinded, placebo-controlled trial to determine if IV dexamethasone more quickly than placebo assists resolution of Posterior Reversible Encephalopathy Syndrome (PRES) encountered in eclamptic patients. All patients regardless of assignment to placebo or steroid will receive standard therapy to include magnesium sulfate, blood pressure medications and diuretics. We hypothesize that the addition of dexamethasone to standard therapy will accelerate CNS recovery more quickly than standard management without dexamethasone.