[Intracranial occlusion of the internal carotid artery after minor closed head injury]

Thrombosis of the extracranial portion of the internal carotid artery as a result of nonpenetrating head and neck injury is not uncommon. However, intracranial occlusion of the internal carotid artery after minor head and neck injury without skull fracture is rare. We report a case of 14-year-old male who suffered a minor head injury during an athletic meeting of his school and developed a right hemiparesis and a lethargy state resulting from thrombosis of the supraclinoid portion of the left internal carotid artery. On admission, skull films and a CT scan revealed no abnormality. One hour later, he fully recovered. One day later, no definite lesions were detected on T1-weighted and T2-weighted image of MRI, but an abnormal high signal lesion in the left frontal lobe was detected on diffusion-weighted image of MRI. On additional MR angiography, intracranial occlusion of the internal carotid artery due to dissection was demonstrated.