Subdural hematoma without subarachnoid hemorrhage caused by ruptured traumatic distal aneurysm of anterior cerebral artery

Objective. To describe a rare complication of non-penetrating traumatic brain injury. Material and methods. We present a 16-year-old patient with multiple skeletal lesions and mild traumatic brain injury (TBI). Two weeks after injury, clinical status suddenly worsened due to large subdural hematoma without signs of subarachnoid hemorrhage despite normal neuroimaging data at baseline. Results. Examination revealed pericallosal artery aneurysm. Microsurgical intervention with aneurysm excision was performed. Histological examination revealed thrombotic masses containing fibrin and no vascular walls of aneurysm. Therefore, the aneurysm was regarded as traumatic false aneurysm resulting from detachment of small artery. There were no neurological disorders at discharge. Conclusion. Acute subdural hematoma in delayed period after TBI requires CT angiography to rule out traumatic aneurysm.