Neutrophil-to-Lymphocyte Ratio and Traumatic Brain Injury: A Review Study

Traumatic brain injury (TBI) is the leading cause of morbidity and mortality worldwide. Several prognostic factors have been developed to predict functional outcomes and mortality rate in patients with TBI. Neutrophil-to-lymphocyte ratio (NLR) is an objective, available, low-cost, and reproducible indicator of inflammation. It is also a marker of extensive secondary damage caused by neutrophils and their products to the cerebral tissue. Accordingly, NLR has been proposed as a valuable outcome predictor in patients with TBI. Evidence emerging from several studies shows that higher NLR value is an independent predictor of poorer functional outcomes and higher mortality rate in patients with severe TBI. Further, higher NLR value is in correlation with lower Glasgow Coma Scale scores. Thus its role as a complementary index to other factors, such as Glasgow Coma Scale, in predicting outcomes after TBI is under investigation. This review aims at gathering the most recent data on the prognostic value of NLR in patients with TBI.