Risk factors for poor outcome in posterior reversible encephalopathy syndrome: systematic review and meta-analysis

The roles of clinical etiology and symptoms, imaging findings and biochemical parameters in predicting the prognosis of posterior reversible encephalopathy syndrome (PRES) have not been well-characterized. We perform a meta-analysis of all published studies to assess the value of various risk factors in predicting the prognosis of PRES.Searches of the PubMed, EMBASE, Cochrane Library, and Web of Science databases were performed to identify the eligible studies. The odds ratios (ORs) with their corresponding 95% confidence interval (CI) for related risk factors were used to calculate the pooled estimates of the outcomes.Six studies with 448 cases were included in the meta-analysis. Hemorrhage was associated with high risk for poor outcome in patients with PRES. Toxemia of pregnancy (pre-eclampsia/eclampsia) was associated with improved outcome in PRES patients. Cytotoxic edema was noted to be related to poor outcome, but did not show statistical significance. The pooled OR for hemorrhage, pre-eclampsia/eclampsia, cytotoxic edema was 4.93 (95% CI: 3.94-6.17; P0.00001), 0.24 (95% CI: 0.15-0.40; P0.00001) and 2.59 (95% CI: 0.84-7.99; P=0.10), respectively.PRES patients with hemorrhage or cytotoxic edema are likely to have poor outcomes. Pre-eclampsia/eclampsia is associated with reduced risk of poor outcome in patients with PRES.