[Penetrating brain injury and traumatic aneurysm caused by a nail gun].

A rare case of penetrating brain injury and traumatic aneurysm caused by a nail gun was described. A 45-year-old male was admitted to our hospital on October 13, 1995 due to a penetrating head injury. He had used a nail gun in a suicide attempt. On admission, he presented with moderate consciousness disturbance, right hemiparesis and aphasia. Several small wounds were observed at the bilateral temporal scalp. The skull films showed that there were five nails in the left side and four nails in the right side perforating in the skull. The CT revealed a small hematoma at the left temporal lobe. The cerebral angiograms did not show any particular findings. Under local anesthesia, each nail was extracted carefully. Suddenly, his neurological damage aggravated and the CT showed a massive hematoma in the left temporal lobe. Emergent craniotomy was performed and the hematoma was totally evacuated. Rehabilitation was carried out and he recovered enough to be able to walk. Angiograms four months after the injury revealed the formation of a traumatic aneurysm at the peripheral part of the left middle cerebral artery (cortical cerebral aneurysm). We did not perform a direct operation for the aneurysm since the contrast medium remained in the aneurysm until the late venous phase. This aneurysm disappeared spontaneously after another four months' observation. Although many penetrated head injuries have been previously reported, the present case is the first report of a traumatic aneurysm associated with nail gun injury.