Abstract
Posterior reversible encephalopathy syndrome is a multifactorial neurological disorder characterized by clinical and neuroimaging findings. The “vasogenic theory” suggests that, in this condition, disrupted cerebrovascular autoregulation leads to blood‐brain barrier failure and vasogenic edema. Posterior reversible encephalopathy syndrome is commonly associated with hypertension, chemotherapy, and transplantation, but neurosurgical patients, including those undergoing digital subtraction angiography, are also at elevated risk. A patient with a history of traumatic brain injury underwent surveillance digital subtraction angiography for a clipped pseudoaneurysm. Periprocedurally, the patient developed left gaze deviation, right hemiplegia, seizures, and magnetic resonance imaging findings consistent with posterior reversible encephalopathy syndrome. The diagnosis relied on distinct radiographic features, normal laboratory results, electroencephalography consistent with encephalopathy, no evidence of infection, a history of traumatic brain injury, and spontaneous clinical improvement. Posterior reversible encephalopathy syndrome can be triggered by cerebral blood flow changes or cytotoxic endothelial damage, particularly in individuals with compromised blood‐brain barrier integrity. Awareness of risk factors, pathophysiology, and clinical and radiographic patterns is crucial for accurate diagnosis.