Posterior reversible encephalopathy syndrome following hemodynamic treatment of aneurysmal subarachnoid hemorrhage-induced vasospasm.

Posterior reversible encephalopathy syndrome (PRES) is an uncommon but significant complication of hemodynamic therapy after aneurysmal subarachnoid hemorrhage (aSAH)-induced vasospasm. We performed a PubMed literature search for the period January 1999 to January 2015 using the search terms "posterior reversible encephalopathy syndrome", "subarachnoid hemorrhage", "vasospasm", and "hypertensive encephalopathy", and identified nine cases of PRES after aSAH-induced vasospasm in the literature. We also present a 63-year-old man with aSAH complicated by vasospasm treated with hemodynamic augmentation who subsequently developed PRES. Imaging following development of PRES symptoms shows vasogenic edema in the white matter of the parietal and occipital lobes. Age, sex, history of hypertension, and baseline blood pressure were variable among patients in the literature review. In all cases, patients improved both from a radiological and clinical perspective following blood pressure reduction. To summarize, PRES is a rare complication of hemodynamic therapy for vasospasm following aSAH. The literature at the time of writing demonstrates no common pattern with regard to patient demographics, medical history, or mode of treatment for symptomatic vasospasm. Given its sporadic and unpredictable nature, considering PRES in the differential diagnosis is important when addressing neurological decline following hemodynamic treatment of vasospasm related to aSAH.