The Association between Neutrophil lymphocyte ratio(NLR) and Perihematomal edema(PHE) in cerebral hemorrhage: a multicenter retrospective study

Yanwei Liu¹Qi Liu²Jun Wei¹Shiqiang Yang^3,4*

• ¹Department of Neurology, First People's Hospital of Yibin, Sichuan, China
• ²Department of Neurosurgery, Sichuan No.2 Hospital of Traditional Chinese Medicine, Chengdu, Sichuan Province, China
• ³Department of Neurosurgery, First People's Hospital of Yibin, Sichuan, China
• ⁴Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China

BACKGROUND: Perihematomal edema (PHE) after a brain haemorrhage is an increase in the water content of the brain tissue surrounding the haematoma, which can be observed and measured on imaging.PHE is one of the major secondary brain injuries after a brain haemorrhage and is strongly associated with poor patient prognosis.The relationship between the neutrophil-lymphocyte ratio (NLR) and cerebral oedema after cerebral haemorrhage remains unclear.METHODS:Data for this study were obtained from a registry database of hospital admissions at two medical institutions covering the population of southwest China. The researchers compared outcomes, including demographics, medical history and lesion characteristics, for all included cases. The primary exposure factor for this study was NLR on admission (NLR1), while NLR measured between 3-5 days of treatment (NLR2) was used as a secondary exposure factor for comparison. The study outcome was the degree of PHE after 5-7 days of standardised treatment. The association between NLR and PHE was examined using Restricted cubic spline(RCS) and Logistic regression modelling, and absolute rate differences and risk ratios with 95% confidence intervals were calculated. RESULTS:A total of 143 patients with confirmed hypertensive cerebral haemorrhage were finally included. Their mean age was 52.8±9.1 years and 53.1% were female. Restricted cubic spline analysis suggested a linear positive correlation between admission NLR and PHE. Logistic regression analysis adjusted for covariates showed that admission NLR was significantly associated with the risk of developing moderate to severe PHE (OR, 1.61 [95% CI, 1.03-2.5]; P=0.035). In addition, NLR was divided into higher and lower groups according to the median and then analysed by logistic model regression with multiple covariate adjustment. The results showed that a higher NLR was significantly associated with a higher risk of moderate to severe PHE compared to the lower group (OR, 2.47 [95% CI,]; P=0.021). These results remained stable in subsequent subgroup and sensitivity analyses.