An unexpected turn: Posterior reversible encephalopathy syndrome following microsurgical resection of a brain arteriovenous malformation.

Background: Cerebral arteriovenous malformations (AVMs) are rare congenital vascular anomalies, often presenting with intracranial hemorrhage or seizures. Posterior reversible encephalopathy syndrome (PRES) is a distinct neurological condition characterized by vasogenic edema, primarily affecting posterior brain regions and typically associated with hypertensive crises, eclampsia, or immunosuppressive therapies. However, its occurrence following neurosurgical interventions is exceptionally rare. This case report documents the first instance of PRES following the resection of a Spetzler-Martin grade I frontal AVM, emphasizing the importance of early recognition and management of this rare complication. Case Description: A 27-year-old woman underwent navigation-assisted resection of a right frontal AVM. The procedure was uneventful; however, in the immediate postoperative period, she experienced a generalized tonic-clonic seizure, agitation, dysconjugate gaze, and altered consciousness. Brain magnetic resonance imaging revealed diffuse high fluid-attenuated inversion recovery signal abnormalities in the brainstem, cerebellum, thalami, basal ganglia, and cerebral hemispheres, consistent with central PRES. The patient was managed with supportive care, resulting in a full clinical and radiographic recovery within 3 weeks. Follow-up imaging confirmed the resolution of PRES-related changes, and she remained seizure-free after antiseizure medication tapering. Conclusion: This case underscores the critical importance of early neuroimaging in evaluating unexpected postoperative neurological symptoms. Recognizing central PRES and its atypical radiographic patterns enables timely diagnosis and appropriate management, avoiding unnecessary interventions. The pathophysiology likely involves postoperative endothelial dysfunction and disrupted autoregulation. This report underscores the importance of considering PRES in postoperative neurological complications and calls for further research into its mechanisms and optimal management.