Delayed Posterior Fossa Hemorrhage Following a Tangential Gunshot Wound to the Occiput in a Patient With Chronic Liver Disease: A Case Report.

Gunshot wounds (GSWs) to the head and neck are a common etiology of traumatic brain injury. Tangential GSWs (TGSWs) are a subset of GSWs wherein the missile penetrates tissue adjacent to the cranium, causing varying degrees of intracranial injury. Most patients sustaining TGSWs present with relatively benign neurological findings, and while a significant proportion have varying degrees of intracranial hemorrhage (ICH) on computed tomography, these tend to respond well to nonoperative management. We present a case report of a 28-year-old male who sustained a TGSW to the occiput, with a nonfocal neurological examination, small-volume posterior fossa ICH, a blunt vertebral artery injury (BVAI), and hepatic coagulopathy, who rapidly decompensated six hours after presenting due to massive posterior fossa hemorrhage with brainstem compression, requiring emergent cardiopulmonary resuscitation followed by suboccipital decompression and cerebrospinal fluid diversion. We propose that the patient's BVAI led to an unexpected thromboembolic event, precipitating an ischemic stroke that underwent hemorrhagic conversion in the setting of coagulopathy. This case report emphasizes the insidious danger that TGSWs to the head and neck present to patients, and risk factors for poor outcomes, such as BVAI and coagulopathy. This report also highlights potential intraoperative challenges during surgery for acute mass lesions in the posterior fossa, such as neurogenic shock and pulmonary edema, that warrant careful consideration and preparation in neurosurgical cases.