Moving bullet syndrome: a complication of penetrating head injury.

Penetrating injuries, by definition, result in retained bullets or fragments. Usually, these fragments are removed surgically during wound debridement. Occasionally, the position of the bullet may preclude removal if it is thought that surgery could exacerbate neurologic damage. Complications from retained fragments are uncommon. One rare complication is the spontaneous migration of the fragment. Two cases of spontaneous migration of retained bullets are presented. In both cases neurologic deterioration was noted and computed tomographic imaging was diagnostic. In one case, this complication delayed transfer from the acute care hospital to rehabilitation. In the other case, the migrating bullet was removed during the inpatient rehabilitation stay. Each person improved neurologically after the migrating bullet fragment was removed. Additionally, functional progress was marked in both persons and symptomatic relief noted. Rehabilitation physicians caring for survivors of penetrating brain injuries need to be aware of this potentially devastating phenomenon.