[Patient with posterior reversible encephalopathy syndrome with prolonged disturbance of consciousness and convulsion after cerebral aneurysm surgery].

A 73-year-old patient developed convulsion and prolonged disturbance of consciousness after clipping surgery for unruptured cerebral aneurysm. The patient's consciousness improved four days after surgery, and radiological findings suggested posterior reversible encephalopathy syndrome (PRES). The cause of PRES is thought to be dysfunction of blood brain barrier by a sudden increase in blood pressure. In case of unexplained convulsion and decreased level of consciousness, PRES should be considered with radiographic examinations including CT and MRI.