2010 年 23 巻 1 号 p. 17-22
A case of bow hunter's stroke with anomalies of the craniocervical junction is reported. The patient, a 22-year-old man, was admitted to our hospital complaining of neck pain, dizziness and gait unsteadiness. The symptoms appeared a day after he had turned his neck to an extreme extent during sleep. Diffusion-weighted MRI demonstrated acute cerebral infarction in the area supplied by the left posterior inferior cerebellar artery. Plain X-ray of the skull and neck and cervical CT revealed anomalies of the craniocervical junction, including basilar impression, atlanto-axial dislocation and atlanto-occipital assimilation. Carotid ultrasonography showed normal flow in the right vertebral artery (VA) in the midline neck position. However, end-diastolic flow of the right VA disappeared when the head was turned 80 degrees to the left. Cerebral angiography also revealed obstruction of the right VA at the C1－2level on rotation of the head 80 degrees to the left. The left VA appeared hypoplastic. An instrumented posterior occipitocervical fusion was performed. Postoperative ultrasound examination revealed recovery of right VA flow on head rotation to the left. This case demonstrated the usefulness of carotid ultrasonography with head rotation for diagnosis of bow hunter's stroke.