Cerebrovascular Vasospasm, Normal Perfusion Pressure Breakthrough Edema, and Posterior Reversible Encephalopathy Syndrome (PRES) in Neurosurgical Critical Care

Abstract

Cerebrovascular vasospasm and delayed cerebral ischemia can occur in 30% of patients with aneurysmal subarachnoid hemorrhage. While data supports prophylactic use of nimodipine for neuroprotection, vigilant monitoring using clinical exam, Transcranial Doppler (TCD), CT angiography (CTA), or angiography and early intervention for symptomatic vasospasm using hemodynamic augmentation and/or endovascular techniques are essential to prevent adverse outcomes. Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible acute neurological symptoms associated with edema involving parieto-occipital and other brain regions. Consideration of the broad differential diagnoses for PRES, early identification and removal of the inciting agent, and aggressive control of blood pressure are key factors in management. Normal perfusion pressure breakthrough (NPPB) is a less frequent condition characterized by cerebral edema or hemorrhage that affects the ipsilateral hemisphere, following surgical treatment of arteriovenous malformations. At least two theories exist on its pathophysiology. The identification of clinical and radiological predictors, intraoperative prevention, and postoperative monitoring can help in early identification and symptomatic management.