Predicting cerebral edema in ischemic stroke patients

Objectives To produce a scoring system for predicting the development of edema in ischemic stroke patients without edema on admission. Methods This retrospective study included 572 ischemic stroke patients (73.3 +/- 13.0years, 300 male) without signs of cerebral edema on the first CT scan, which was performed on admission. Another scan was normally performed 3days later, and subsequently whenever needed. Edema was defined as cerebral hypodensity with compression of lateral ventricles. The main clinical, laboratory, and instrumental variables obtained during the first 24h were related to the appearance of edema on the CT scans performed after the first one. Results Cerebral edema occurred in 158 patients (27.6%) after a median time of 4days. The variables independently associated with edema development were (odds ratio, 95% CI) the following: (1) total anterior circulation syndrome (4.20, 2.55-6.93; P<0.0001), (2) hyperdense appearance of middle cerebral artery (4.12, 2.03-8.36; P=0.0001), (3) closed eyes (2.53, 1.39-4.60; P=0.002), (4) vomiting (3.53, 1.45-8.60; P=0.006), (5) lacunar cerebral syndrome (0.36, 0.17-0.77; P=0.008); and (6) white matter lesions (0.53, 0.33-0.86; P=0.01). Counting one positive point for the first four variables and one negative point for the last two variables, a scoring system (E-score) was built. Cerebral edema could be predicted when the score was >= 1 (positive predictive value 61.6%, specificity 85.3%, sensitivity 62.0%). The area under the receiver operating characteristic curve was 0.78. Conclusions In ischemic stroke patients, six variables obtained during the first 24h of hospitalization were predictive of subsequent cerebral edema development.