A comparison of clinical characteristics, radiographic findings, and outcomes of bihemispheric versus unihemispheric gunshot wounds to the head.

Introduction: Unihemispheric head gunshot wound (HGSW) are associated with improved survival; however, specific clinical and radiographic characteristics associated with survival have not been clearly defined. To further guide prognosis estimates and care discussions, this study aims to identify unihemispheric HGSWs injury patterns; comparing them to bihemispheric HGSWs characterizing factors associated with improved clinical outcomes and survival.

Methods: Patients presenting to our Level 1 trauma center from January 2013 through May 2019 with HGSW injury were reviewed. Patients were grouped into those with unihemispheric versus bihemispheric HGSWs and survivors versus non-survivors. Clinical variables and head computed tomography (CT) features were compared using comparative statistics.

Results: 62 HGSW patients met study criteria (unihemispheric = 33, bihemispheric = 29). Regardless of injury type, avoidance of injury to multiple lobes, temporal, parietal and basal ganglia brain regions and intracranial vascular injury were also associated with survival (p < 0.05). Lower admission GCS score and lower motor GCS score was associated with reduced survival in unihemispheric HGSW injury (p < 0.05). Unihemispheric HGSW survivors demonstrated improved clinical outcomes, with reduced hospital length of stay (5 days vs. 47 days, p = 0.014) and intensive care unit length of stay (3 days vs. 20 days, p = 0.021) and more favorable disposition location.

Conclusion: We found presenting clinical features and CT imaging patterns previously associated with improved survival in HGSW patients is similar in unihemispheric specific injuries. Importantly, a more favorable admission GCS score may portend survivability in unihemsipheric HGSW. Furthermore, unihemispheric HGSW survivors may have improved clinical outcomes, length of stay and disposition location.