A Case of Posterior Reversible Encephalopathy Syndrome After Surgical Clipping of Unruptured Cerebral Aneurysm

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible edematous lesions on imaging examinations, along with symptoms of altered consciousness disorder and seizures. Various factors associated with PRES have been reported. However, we encountered a very rare case that developed after clipping surgery for unruptured cerebral aneurysm. CASE DESCRIPTION: A 74-year-old man with a history of hypertension presented with an unruptured right middle cerebral artery aneurysm and underwent cranial clipping surgery. After surgery, he developed consciousness disorder and epilepsy after delayed awakening from general anesthesia. Radiological examinations revealed multiple edematous lesions, strongly suggesting PRES, and excluding asymmetry consistent with the area of craniotomy. With conservative treatment, symptoms and radiological findings almost disappeared. Symptoms and imaging findings remaining at the area of craniotomy were attributed to the severe difference in cerebral perfusion pressure due to craniotomy. CONCLUSIONS: Based on the literature, this case was considered to represent PRES caused by rapid blood pressure fluctuations accompanying general anesthesia for clipping surgery. Practitioners must keep PRES in mind as a rare complication after clipping for unruptured cerebral aneurysms. PRES developing after craniotomy shows unilaterality and may become severe in the craniotomy area and leave sequelae.