title: Cervical Myelopathy Caused by Bilateral Laminar Cleft of the Axis: Case Report and Review of Literature.
abstract: BACKGROUND
  Cervical myelopathy due to bilateral laminar cleft of the axis is extremely rare, and few cases have been previously reported. However, its treatment is relatively simple. Surgical removal of the anomalous bony structure compromising the spinal canal can sufficiently achieve a good outcome.
  
  
  METHODS
  A 56-year-old man presented with a 2-year history of stiffness of the left upper and lower extremities. Cervical spine computed tomography showed a bony cleft at both laminae of the posterior arch of the axis, with obvious cord compression on magnetic resonance imaging. Although absence of right pedicle and spina bifida of C7 were also detected, there was no cord compression at this level. The patient underwent surgical removal of the anomalous laminar cleft and the spinous process of the axis. Postoperatively, he improved rapidly and was discharged on the seventh postoperative day. He was asymptomatic at the 3-year follow-up. After surgery, the preoperative myelopathy status was much improved. About 7 years after surgery, radiographs showed no kyphosis and instability.
  
  
  CONCLUSIONS
  Invaginated bilateral laminar cleft of the axis is a rare cause of cervical myelopathy. The findings in our case should broaden the radiographic differential diagnosis in patients with cervical myelopathy. Surgical removal is an appropriate and simple treatment for this patient, resulting in a satisfactory outcome.
authors.affiliation: Department of Neurosurgery, Chonnam National University Hospital and Medical School, Gwangju, Korea.
authors.forename: Bong Ju
authors.initials: BJ
authors.lastname: Moon
authors.affiliation: Department of Neurosurgery, Chonnam National University Hospital and Medical School, Gwangju, Korea.
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Choi
authors.affiliation: Department of Neurosurgery, Chonnam National University Hospital and Medical School, Gwangju, Korea. Electronic address: jkl@chonnam.ac.kr.
authors.forename: Jung-Kil
authors.initials: JK
authors.lastname: Lee
mesh_terms: D001368:Axis, Cervical Vertebra / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D002574:Cervical Vertebrae; D019299:Decompression, Surgical / Q000379:methods; D006801:Humans; D007796:Laminectomy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D013117:Spinal Cord Compression / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Anomalous spinous process; Axis; Cervical myelopathy; Cleft; Congenital anomaly; Invagination