Unusual Delayed Presentation of Posterior Reversible Encephalopathy Syndrome Following Vestibular Schwannoma Surgery: A Rare Neurologic Emergency.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic condition that manifests with heterogeneous clinical findings, including altered mental status, seizure, vision loss, and vomiting. It characteristically leads to diffuse subcortical vasogenic edema, most commonly in the parieto-occipital regions. Although frequently reported with conditions such as hypertension, eclampsia, sepsis, electrolyte imbalances, autoimmune diseases, and immunosuppressive therapy, PRES may rarely occur after surgery for posterior fossa tumors. In the postsurgical setting, clinical features of PRES usually develop intraoperatively or in the immediate postoperative period. Delayed presentation months after the surgery has not been reported earlier.

CASE DESCRIPTION: A 23-year-old woman who underwent surgery for vestibular schwannoma 8 months earlier presented with altered sensorium, generalized seizures, and high blood pressure. Common possibilities were ruled out by clinical history, diagnostic imaging, and appropriate blood tests. Radiologic imaging revealed rapid recurrence of tumor with diffuse subcortical edema involving both hemispheres. The patient showed complete neurologic recovery with antihypertensive and antiepileptic drugs.

CONCLUSIONS: PRES is a rare but important cause of acute neurologic deterioration following posterior fossa tumor surgery. Prompt diagnosis and aggressive treatment often lead to complete neurologic recovery.