"A-38-year-old man suddenly developed nausea, vomiting and vertigo during chiropractic neck manipulation. This was followed by right hemiplegia, right deep sensory disturbance and left hypoglossal nerve palsy, consistent with the medial medullary infarction (Dejerine syndrome). The MRI revealed infarction at left medial part of the medulla. The vertebral angiogram and MRA showed marked narrowing of the left vertebral artery. X-rays of the cervical spine showed no spondylosis, dislocation nor osteolysis of the odontoid process….. The mechanism was suggested that rotation and tilting of the neck stretches and compresses the vertebral artery at the cervical joint causing injury to the vessel, with an intimal tearing, dissection, and pseudoaneurysm formation. Consequently, the present case may be caused by injury to the left vertebral artery with an intimal tearing during neck manipulation sufficient to cause disection and subsequent infarction of the brain stem." No To Shinkei (February 2003) [Japanese article]