Posterior Reversible Encephalopathy Syndrome Causing Vision Loss After Endoscopic Endonasal Resection of Pituitary Adenoma

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual changes, and seizure combined with brain imaging consistent with cerebral edema without infarction. To the best of our knowledge, we report the first case of PRES after an endoscopic endonasal resection of a pituitary macroadenoma. A 59-year-old woman was diagnosed with a pituitary macroadenoma, for which she underwent endoscopic endonasal extracapsular resection. After an uneventful initial postoperative recovery, the patient experienced sudden onset of emesis, confusion, vision loss, and severe hypertension. Emergent computed tomography showed normal postoperative changes, with no signs of hematoma or infarction. Magnetic resonance imaging (MRI) showed fluid-attenuated inversion recovery changes in the posterior lobes and thalamus, consistent with PRES. Cerebral angiography showed no vascular abnormalities. Blood pressure control was the primary treatment modality. Within 10 days, the patient was neurologically intact except for right homonymous hemianopsia. Follow-up MRI showed resolution of the PRES with an area of infarction in the left occipital lobe. At 5 years follow-up, the patient reported minimal blurred vision. MRI showed encephalomalacia at the old infarct area, and her visual field testing was unremarkable. Although rare in neurosurgical patients, PRES must be considered in patients who develop acute vision loss and mental status changes associated with hypertension after surgery, including endoscopic endonasal surgery. PRES has the potential for significant neurologic morbidity, if not treated in a timely manner. Early recognition and treatment, with blood pressure control mainly, are therefore mandatory after a surgical complication, such as a postoperative hematoma, has been ruled out.