Association Between Neutrophil to Lymphocyte Ratio and Malignant Brain Edema in Patients With Large Hemispheric Infarction

Introduction: Malignant brain edema (MBE) is a life-threatening complication for patients with large hemispheric infarction (LHI). Stroke-related inflammatory responses may cause secondary brain injury and lead to brain edema. The neutrophil to lymphocyte ratio (NLR) is a well-known systemic inflammatory biomarker. The aim of this study was to evaluate if NLR is associated with MBE in patients with LHI. Methods: A retrospective analysis was performed of LHI patients within 24 h from stroke onset admitted to the Department of Neurology, West China Hospital from January 1, 2017 to December 31, 2018. Blood samples were collected upon admission. MBE was diagnosed by any neurological deterioration accompanied by brain edema in follow-up images. Patients were categorized according to NLR tertiles. Univariate analyses were performed to identify potential confounding variables and a multivariate logistic regression analysis was conducted to determine the correlation between NLR and MBE. Results: A total of 257 patients with a mean age of 68.6 ± 14.0 years were identified. Among them, 83 (32.3%) patients developed MBE with a median time of one day (interquartile range [IQR] 0-2 days) from hospital admission. An elevated NLR was related to an increased risk of MBE when the lowest and highest tertiles were compared (odds ratio 2.27, 95% confidence interval 1.11-4.62, p = 0.024). The risk of MBE increased with the increase of NLR in a dosedependent manner (p for trend = 0.029). No interaction between potential modifiers and NLR on MBE was observed. Conclusions: Higher NLR was associated with an increased risk of MBE in patients with LHI.