Dynamic Neuron-specific Enolase Level to Glasgow Coma Scale Score Ratio Changes: A Reliable Indicator for Long-Term Neurological Function in Diffuse Axonal Injury

Abstract

Background: Patients with diffuse axonal injury (DAI) are often plagued by sequelae, and the current indicators for predicting long-term neurological function are not accurate enough. Our previous studies have found that serum Neuron-specific enolase (NSE) level to Glasgow Coma Scale (GCS) score ratio(NGR) at admission could be used as an independent predictor of DAI, the purpose of this study was to explore the accuracy of dynamic changes of NGR in predicting long-term neurological function in patients with DAI. Methods: Patients with DAI were included based on clinical MRI as the diagnostic standard, and divided into two groups according to the 6-month Extended Glasgow Outcome Scale (GOSE) as the prognosis indicator. The differences in clinical parameters between the two groups of patients were compared by Pearson correlation analysis. The trend of dynamic changes in NSE, GCS, and NGR at 1st, 3rd, 5th, 7th and 14th days after injury were shown by line graphs. The predictive efficacy of various parameters for long-term neurological function were further analyzed by receiver operator characteristic (ROC) curves. Results: Among the 102 DAI patients, 75 (73.5%) were classified to favorable outcome group (GOSE5-8) and 27 (26.5%) to unfavorable outcome (GOSE1-4). The NSE, NGR and Marshall CT grade at the first day after injury in the favorable outcome group were significantly lower than those in the unfavorable outcome group (p = 0.005, p < 0.001, p = 0.002), but the GCS score was significantly higher than that of the latter (p = 0.006). There was a negative correlation between NGR at 1st, 3rd, 5th, 7th, and 14th days post-TBI (r1=-0.557, r3=-0.746, r5=-0.761, r7=-0.727, r14=-0.694), and the 6-month GOSE. DAI patients with a favorable outcome exhibited a gradual decline in NGR. The area under the ROC curves (AUC) of NGR at 1st, 3rd and 5th days post-TBI were 0.751, 0.913, 0.934, which were the largest among the three parameters. Conclusions: The dynamic changes of NGR may be an accurate predictor of long-term neurological function in patients with DAI. Trial registration: ISRCTN, ChiCTR2100044352. Registered 17 March 2021, https://www.chictr.org.cn/