Higher Discharge GCS Score is Associated with Both Survival and Long-term Functional Recovery in Patients with Clinically Defined Diffuse Axonal Injury

Abstract

Background: Diffuse axonal injury (DAI) refers to widespread axonal damage due to traumatic brain injury. There are very few studies that have specifically looked at outcomes in patients with DAI, where the injury is not associated with accompanying focal lesions (such as haematomas and other mass lesions) or ischaemic brain injury. In this study, we assessed factors that predict mortality and long-term functional outcome of patients with DAI who underwent treatment and rehabilitation in a tertiary care hospital in South India. Methodology: Long-term outcome and neuropsychiatric sequelae were assessed in 160 patients with DAI, who underwent rehabilitation and were on regular follow-up for a median duration of 5 years (interquartile range = 3–6). Cox proportional hazards and logistic regression models were used to determine factors associated with mortality and functional outcome (Glasgow Outcome Scale-Extended [GOSE], Mayo-Portland Adaptability Inventory [MPAI] and Neuropsychiatric Inventory [NPI]). Results: Majority of the 160 patients included in this study were young males (92%) who presented with severe head injury (Glasgow Coma Scale [GCS] score of 5.6 ± 2.1). At the time of follow-up, 94 (58.75%) patients were alive, while 66 (41.25%) were dead. Patients who were alive at the time of follow-up were significantly younger, had higher GCS score and lower Rotterdam computed tomography (CT) grade at presentation compared to those who died. Compromised airway requiring tracheostomy (χ2 = 21.3; P < 0.001) and abnormal pupil reactivity (χ2 = 30.2, P < 0.001) were significantly associated with mortality. GCS score at discharge was the single most important determinant of mortality (hazard ratio = 0.802, P < 0.001). Among those who were alive, majority (73.4%) had good functional recovery (GOSE score 8). GCS scores (at admission and that at discharge) and Rotterdam CT score independently and significantly predicted MPAI, NPI and caregiver distress scores. Among them, GCS score at discharge was the strongest predictor. In-hospital improvement in GCS correlated with GOSE but not with MPAI and NPI. Conclusion: Higher GCS scores at discharge were strongly associated with both survival and functional recovery in patients with DAI.

Keywords

• diffuse axonal injury
• functional outcome
• glasgow coma scale
• traumatic brain injury