Hello, my name is Bhavli Dowd. I'm a fourth year medical student at East Tennessee State University. I'm currently working as a research fellow at Vanderbilt University and I'm really excited to speak to you all today about penetrating gunshot wounds to the head. I have no disclosures. Traumatic brain injury accounts for about half of all trauma deaths. Penetrating brain injury represents a substantial portion of that with 35,000 cases annually. 20,000 of those cases are due to gunshot wounds to the head and cases have been steadily rising over the past several years. These injuries are devastating and require intensive neurosurgical care. The purpose of our study was to present our experience with gunshot wounds to the head at a level one trauma center over the past 10 years. We initially identified 322 patients with penetrating brain injury from 2009 to 2019 that had survived initial resuscitation. 315 of those were due to gunshot wounds to the head and 297 were identified as neural penetrating on head CT. This was our study cohort. 204 of those were discharged as in-hospital mortalities while 93 were discharged alive. Overall, our demographics were representative of the national populace, but the cohort was predominantly made up of male patients comprising about 85% of the total cohort. The mechanism of injury was primarily due to suicide attempts at 61.3% with assaults at about 21%. When looking at the clinical data, we know that intubation on arrival as well as lower GCS scores, those specifically in the group of three to four were associated with mortality, as well as initial INR and admission. We can see that non-survivors had a greater mean initial INR compared to survivors. We grouped bullet trajectories into four different classifications, unihemispheric slash bifrontal, bihemispheric, posterior fossa, and transventricular. Among all these bullet trajectories, only bihemispheric bullet tracks were significantly associated with mortality. This represented 65.7% of non-survivor cases. This trajectory was defined as bullet track that involved both hemispheres excluding the area of the frontal poles. It was substantially associated with poor outcome in the converse, unilateral slash bifrontal was actually a good prognostic factor. It represented 88.3% of survival cases. This was consistent with prior literature. When looking at interventions by hospital discharge status, we see that CT angiography was conducted in 63 patients, 45% of survivors and 11% of non-survivors. Among neurosurgical interventions, craniotomy was the most frequent in survivors at 43%. Other neurosurgical interventions including EVD and ICP monitor placements were also much more prominent in survivors. This is most likely a function of patient presentation and prognosis based on initial exam and imaging. Essentially, more craniotomies were most likely done in patients with unihemispheric bullet tracks and subsequently more survivors as a result. Coagulation correction was the only intervention significantly associated with mortality. This goes hand in hand with the significantly increased initial INR observed in non-survivors I mentioned earlier. As stated earlier, these gunshot wounds to the head are extremely devastating and patients who suffer them experience an array of complications as a result. CSF leak here we see at any point in care is most prominent, occurring in 55.3% of survivors and 66% of non-survivors. Frequently, this does not require any care further than closing the injury site. 30% of survivors underwent cranioplasty, 17% incurred injury site infection and 9.6% experienced seizure disorders as a result of their injuries. Only 3.2% developed hydrocephalus requiring shunts. I think nothing best illustrates the devastating nature of these injuries more than looking at the survival curve of patients over time. We can see a drastic drop almost immediately in survival within the first couple of days. Essentially, 56% of patients with gunshot wounds to the head die within the first 48 hours. I know this is very bleak, but there is a positive side to all of this. Although only about 33% of patients survive, patients that do survive have a median Glasgow outcome scale score of 4 and a modified Rankin scale score of 2. Both representing very mild disability and overall positive recovery. So, a substantial percentage of those who survive end up with a good outcome following intensive medical care and neurosurgical care. So, what do we take away from all of this? First, that gunshot wounds to the head incur high mortality rates and poor outcomes overall, with over half of patients dying within the first two days. But after surviving this acute period, most have good outcomes. This 48-hour mark represents a critical point at which patients' prognosis of survival is much better. We also see that bihemispheric bullet tracks and increased initial INRs are associated with mortality. Finally, although survivors are the minority, with intensive neurosurgical care, these patients can still maintain good functionality overall, with about 70% of them exhibiting good outcomes. We are currently working with this data to develop a prognostic score that is conditional on survival and that can hopefully better guide neurosurgical care for these acute survivors. These are my references. I want to take this opportunity to thank the AANS for inviting us to present our study. I also want to thank Dr. Aaron Young-Gokhan and Dr. Pat Kelley for all of their mentorship and guidance with this project. I also want to thank Dr. Daniel Wolfson and Randy Alhualia for all of their work on this project. Thank you so much.

penetrating gunshot wounds

head

medical student

neurosurgical care

prognostic score