[Vertebral artery dissection due to the C6 transverse process and laryngeal cartilage associated with vertebral artery anomaly].

A 52-year-old woman complained of the sudden onset of a left temporal headache, left neck stiffness and dizziness. Brain magnetic resonance imaging showed a high-intensity lesion in the right medial medulla. Dynamic cerebral angiography revealed vertebral artery dissection and compression at the C6 level due to a transverse process at the C6 level associated with rightward head rotation. Removal of bone and decompression of the vertebral artery were performed from the C5 to C6 levels. Intraoperasively, obstruction of blood flow due to a laryngeal cartilage that rotated with the passive rotation of the patient's head to the right was found. To the best of our knowledge this is the first reported case of vertebral artery occlusion due to a laryngeal cartilage associated with head rotation.