Visual Hallucinations as a Major Manifestation of Posterior Reversible Encephalopathy Syndrome: Case Report and Literature Review.

We evaluated a 48-year-old woman who had visual hallucinations (VHs) as a major presenting sign of posterior reversible encephalopathy syndrome (PRES). Despite her mild loss of vision, she described various hallucinations after awakening from a comatose state days after a motorcycle collision. VHs are usually accompanied by more severe loss of vision, yet our case and literature review indicate that sudden onset of formed VHs should suggest a possible diagnosis of PRES in patients who have large fluctuations in blood pressure, renal failure, or autoimmune dysfunction, as well as in patients taking cytotoxic agents.