A case of bow hunter's stroke with the complaint of cervical vertigo

Abstract

We report a case of Bow hunter's stroke with the complaint of cervical vertigo. A 48-year-old man complained of cervical vertigo following head rotation to the left. He showed positional nystagmus when his head was rotated to the left in the supine position and, if the head rotation was maintained, he felt a gradual drop into unconsciousness. The positional nystagmus and fainting were not, however, induced in the patient in the left lateral decubitus position without head rotation. Three-dimensional analysis of his positional nystagmus showed its inconsistent rotational axis, which is different from the single rotational axis in patients with peripheral positional nystagmus. These findings suggested the central cervical positional vertigo/nystagmus in the patients. MRI showed an old infarction of the left cerebellum and MRA showed severe hypoplasia of the left vertebral artery. Vertebral angiography showed severe stenosis of the left vertebral artery and the mechanical occlusion of the right vertebral artery by the atlas-axis joint at C 1-C 2 when the patient's head was rotated to the left. Therefore, it is demonstrated that his positional vertigo/nystagmus with fainting caused by head rotation to the left was induced by the vertebrobasilar insufficiency due to mechanical occlusion of the vertebral artery associated with head rotation, resulting in the diagnosis of Bow hunter's stroke in this patient.