The location of intraparenchymal bleeding determines functional outcome after spontaneous subarachnoid hemorrhage

Background and purpose Non‐traumatic subarachnoid hemorrhage (SAH) is a devastating disease associated with high morbidity and mortality. A higher blood burden and the presence of intraparenchymal extension of the bleeding (intracerebral hemorrhage [ICH]) are well known predictors of poor outcome. Only few studies have addressed the role of hematoma location on patient's functional outcome. The main aims were to compare clinical and radiographic characteristics between SAH patients with and without ICH and to compare different ICH localizations in relation to long‐term functional outcome. Methods We prospectively collected data on 280 consecutive SAH patients (aneurysmal and non‐aneurysmal) admitted to a tertiary care hospital between 2010 and 2017 and assessed the initial computed tomography scans of the brain acquired after intensive care unit admission. Poor functional outcome was defined as a modified Rankin Scale score >2, 3 months after SAH. We used multivariable logistic linear regression to investigate associations between ICH location and clinical variables as well as functional outcome. Results Intraparenchymal extension of the hemorrhage was observed in 59/280 patients (21%). The median (interquartile range) ICH volume was 11.3 (4.9–16.2) ml and the location was supratentorial in 55/59 patients (93%). Most parenchymal hemorrhages were located in the frontal (n = 24.41%) and temporal lobes (n = 12.21%), followed by insular ICH (n = 7.12%), corpus callosum (n = 6.10%), parietal (n = 2.3%) and occipital locations (n = 2.3%). Among SAH patients with ICH, those with lesions located in the corpus callosum (n = 6/59) had a significantly higher risk of 3‐month poor functional outcome in comparison to all other ICH locations, even after adjusting for Hunt and Hess grade and age (adjusted odds ratio [adjOR] 50.5, 95% confidence interval [CI] 1.3–2004.2, p = 0.034). These results remained robust when comparing the whole SAH cohort (adjOR 21.7, 95% CI 1.4–347.8, p = 0.030). Conclusions Intraparenchymal bleeding in patients with non‐traumatic SAH, in particular that involving the corpus callosum, strongly predicts functional outcome. Subarachnoid hemorrhage patients with hemorrhagic lesions of the corpus callosum (n = 6/280) are at an elevated risk of unfavorable 3‐month functional outcome.