The malignant stroke indicator is an early indicator of malignant ischemic stroke requiring decompressive hemicraniectomy

Decompressive craniectomy (DHC) can prevent mortality in patients with malignant ischemic stroke. However, no clear criteria have been established to early identify patients, who will develop malignant stroke requiring DHC. In this retrospective observational study, a large patient cohort with ischemic stroke treated between 2010 and 2021, was analyzed. Clinical and radiological parameters were analyzed. Univariate and multivariate regression analyses were performed to identify the parameters to be included in the score. A cohort of 534 patients was included. A malignant stroke indicator (MSI) score was created including age < 70 years with 7 points, midline shift with up to 6 points, unsuccessful recanalization (TICI < 2b) with 6 points, basal cistern effacement with 4 points, and CBV ASPECTS < 6 with 3 points assigned. A MSI score with a cutoff value of 9 showed a high discrimination power concerning the need for DHC (AUC 0.90, p < 0.0001). Patients with MSI-score ≥ 9 had a 22-fold higher probability of needing DHC (odds ratio 22.90, p < 0.0001). The MSI score is a promising tool to predict the need for DHC in patients at risk for developing a malignant stroke and needs to be validated in external cohorts.