Diffuse Axonal Injury Pattern Predicts Timing of In-Hospital Neurologic Recovery: A Retrospective Case Series

Abstract

Diffuse axonal injury (DAI) is a devastating traumatic neurological injury with variable prognosis. Although outcomes such as mortality have been described, the time course of neurological progression is poorly understood. We investigated the association between DAI neuroanatomical injury pattern and neurological recovery timing. A retrospective review of our institution's trauma registry identified patients diagnosed with DAI from 2017-2021. Neuroradiologist review of head CT was used to score DAI severity. In-hospital neurological exams were reviewed, and GCS was calculated for all patients throughout the hospital stay. Categorical variables were analyzed using Fisher's exact test and continuous variables were analyzed using Kruskal-Wallis test. Nineteen DAI patients (Grade 1=8; Grade 2=1; Grade 3=10) were included (mean age 31 years, 79% male). Mean Rotterdam CT score, Injury Severity Scale, and admission GCS were comparable across DAI grades. Mean time in days to follow commands was shorter for those with Grade 1 DAI (9.3) compared to Grade 2 (17 days) or Grade 3 (19 days) DAI (p=0.02). Throughout hospitalization, patients with Grade 1 DAI had higher motor (p=0.006), eye (p=0.001), and total GCS (p=0.011) score compared to those with Grade 2 or 3 DAI. At the time of discharge, total GCS and the frequency of command following was similar across DAI grades. Patients with Grade 1 DAI demonstrated the fastest short-term neurological recovery, although final discharge neurological examination was comparable across DAI grades. DAI classification can provide useful short-term prognostic information regarding in-hospital neurological improvement.