Atypical posterior reversible encephalopathy syndrome following craniotomy for a metastatic lesion: illustrative case.

Background: An 80-year-old male was found to have a metastatic lesion in his cerebrum. He underwent uncomplicated resection with prolonged inhalational anesthesia due to issues with intravenous access prior to surgery. Postoperatively, the patient had persistent altered mental status. Immediate postoperative head computed tomography and continuous electroencephalography were negative for possible causes.

Observations: Standard brain magnetic resonance imaging (MRI) after metastatic resection demonstrated the development of edema in his pons and thalami, concerning for posterior reversible encephalopathy syndrome (PRES). Tight blood pressure control was initiated. His neurological examination returned to baseline. Follow-up MRI showed the resolution of edema.

Lessons: This is a report of PRES hypothesized to be attributable to prolonged inhalational anesthetic. PRES is a disorder in which patients present with altered mentation, seizures, visual impairment, or headache. PRES often occurs due to acute uncontrolled hypertension; however, other conditions, including autoimmune disease and cancer chemotherapy, have been linked. In severe cases, permanent brain damage and death have been reported. The authors present a case of PRES as the cause of severe neurological decline following craniotomy without severe or sustained hypertension. The authors hypothesize that PRES could be caused by blood pressure variability in the perioperative period and prolonged anesthesia. https://thejns.org/doi/10.3171/CASE24245.