Right-to-Left Displacement of an Airgun Lead Bullet after Transorbital Entry into the Skull Complicated by Posttraumatic Epilepsy : A Case Report

Abstract

Penetrating head injury is a serious open cranial injury. In civilians, it is often caused by non-missile, low velocity flying objects that penetrate the skull through a weak cranial structure, forming intracranial foreign bodies. The intracranial foreign body can be displaced due to its special quality, shape, and location. In this paper, we report a rare case of right-to-left displacement of an airgun lead bullet after transorbital entry into the skull complicated by posttraumatic epilepsy, as a reminder to colleagues that intracranial metal foreign bodies maybe displaced intraoperatively. In addition, we have found that the presence of intracranial metallic foreign bodies may be a factor for the posttraumatic epilepsy, and their timely removal appears to be beneficial for epilepsy control.

Keywords: Foreign body migration; Penetrating head injury; Posttraumatic epilepsy.

Fig. 1.

Location of the intracranial foreign body before and after the first surgery. A-D : Preoperative. E-H : Postoperative. The red dots in (C, D, G, and H) indicate the intracranial foreign body which is reconstructed in 3D.

Fig. 2.

The first surgical procedure. A : The skin incision design. B : The arrow in the middle indicates a brain surface wound. C : Intraoperative ultrasound, the highlighted area in the center of the figure is a foreign body shadow, which cannot be located. D : Intraoperative X-ray, the red arrow indicates a foreign body, which cannot be located despite the use of surgical instruments.

Fig. 3.

A : Foreign body trajectory diagram. 1 to 4 in the diagram respectively indicate foreign body trajectory into the skull, foreign body and skull collision reflex point, rebound trajectory and foreign body stay location. B : Location of the intracranial foreign body (red dot) before the second operation, with a slight downward shift compared to the first operation. C and D : The second intraoperative ultrasound for clear visualization of intracerebral structures, the red arrows in (C) indicate the lateral ventricles and the arrow in (D) indicates the foreign body. E-H : The second operation to remove the foreign body, the arrows in (G) and (H) indicate the foreign body.

Fig. 4.

EEG topography. (A-E) are respectively EEG topography at 1 month, 1 year after the first operation, 1 day before reoperation, 1 day after reoperation for seizures, and 2 months after reoperation. EEG : electroencephalography. In these figures, there has been abnormal electrical activity in the right cerebral hemisphere, which may be the location of the seizure foci.