Hemorrhagic transformation of ischemic brain tissue - Asymptomatic or symptomatic?

Background and Purpose - The term symptomatic hemorrhage secondary to ische mic stroke implies a clear causal relationship between clinical deteriorati on and hemorrhagic transformation (HT) regardless of the type of HT. The ai m of this study was to assess which type of HT independently affects clinic al outcome. Methods - We used the data set of the European Cooperative Acute Stroke Stu dy (ECASS) II for a post hoc analysis, All patients had a control CT scan a fter 24 to 96 hours or earlier in case of rapid and severe clinical deterio ration, HT was categorized according to radiological criteria: hemorrhagic infarction type 1 and type 2 and parenchymal hematoma type 1 and type 2, Th e clinical course was prospectively documented with the National Institutes of Health Stroke Scale and the modified Rankin Scale. The independent risk of each type of HT was calculated for clinical deterioration at 24 hours a nd disability and death at 3 months after stroke onset and adjusted for pos sible confounding factors such as age, severity of stroke syndrome at basel ine, and extent of the ischemic lesion on the initial CT, Results - Compared with absence of HT, only parenchymal hematoma type 2 was associated with an increased risk for deterioration at 24 hours after stro ke onset (adjusted odds ratio, 18; 95% CI, 6 to 56) and for death at 3 mont hs (adjusted odds ratio, 11; 95% CI, 3.7 to 36), All other types of HT did not independently increase the risk of late deterioration. Conclusions - Only parenchymal hematoma type 2 independently causes clinica l deterioration and impairs prognosis. It has a distinct radiological featu re: it is a dense homogeneous hematoma > 30% of the ischemic lesion volume with significant space-occupying effect.