Long-term outcomes of combat casualties sustaining penetrating traumatic brain injury

BACKGROUND: Previous studies have documented short-term functional outcomes for patients sustaining penetrating brain injuries (PBIs). However, little is known regarding the long-term functional outcome in this patient population. Therefore, we sought to describe the long-term functional outcomes of combat casualties sustaining PBI. METHODS: Prospective data were collected from 2,443 patients admitted to a single military institution during an 8-year period from 2003 to 2011. PBI was identified in 137 patients and constitute the study cohort. Patients were stratified by age, Injury Severity Score (ISS) and admission Glasgow Coma Scale (aGCS) score. Glasgow Outcome Scale (GOS) scores were calculated at discharge, 6 months, 1 year and 2 years. Patients with a GOS score of 4 or greater were considered to have attained functional independence (FI). RESULTS: The mean (SD) age of the cohort was 25 (7) years, mean (SD) ISS was 28 (9), and mean (SD) aGCS score was 8.8 (4.0). PBI mechanisms included gunshot wounds (31%) and blast injuries (69%). Invasive intracranial monitoring was used in 80% of patients, and 86.9% of the study cohort underwent neurosurgical intervention. Complications included cerebrospinal fluid leak (8.3%), venous thromboembolic events (15.3%), meningitis (24.8%), systemic infection (27.0%), and mortality (5.8%). The cohort was stratified by aGCS score and showed significant improvement in functional status when mean discharge GOS score was compared with mean GOS score at 2 years. For those with aGCS score of 3 to 5 (2.3 [0.9] vs. 2.9 [1.4], p < 0.01), 32% progressed to FI. For those with aGCS score of 6 to 8 (3.1 [0.7] vs. 4.0 [1.2], p < 0.0001), 63% progressed to FI. For those with aGCS score of 9 to 11 (3.3 [0.5] vs. 4.3 [0.8], p < 0.0001), 74% progressed to FI. For those with aGCS score of 12 to 15 (3.9 [0.7] vs. 4.8 [0.4], p < 0.00001), 100% progressed to FI. CONCLUSION: Combat casualties with PBI demonstrated significant improvement in functional status up to 2 years from discharge, and a large proportion of patients sustaining severe PBI attained FI. LEVEL OF EVIDENCE: Epidemiologic study, level III.