title: Upper cervical cord compression due to a C-1 posterior arch in a patient with ossification of the posterior longitudinal ligament and a kyphotic cervical spine in the protruded-head position: case report.
abstract: In this paper the authors report the case of a patient with ossification of the posterior longitudinal ligament (OPLL) below the axial vertebra (C-2) at the kyphotic cervical spine, with an atlas vertebra (C-1) posterior arch that compressed the spinal cord with the head in a pathognomonic position, similar to a protruded position. This condition appears to be very rare. The morphological findings between the kyphotic cervical spine and OPLL, the upper occipitocervical junction, and the protruded-head position are discussed. A 40-year-old man presented with severe pain radiating to both legs when he yawned, sneezed, or extended his jaw (a protruded-head position). A kyphotic cervical spine with OPLL below C-2 was observed using CT and radiography, yet sagittal T2-weighted MRI failed to identify abnormal findings in a neutral or extension position, except for a slight cervical canal stenosis. However, in a pathognomonic protruded-head position, sagittal T2-weighted MRI showed a C-1 posterior arch that severely compressed the spinal cord at the upper cervical level. Therefore, the authors believe that the severe pain radiating to both legs was caused by a spinal canal stenosis due to a C-1 posterior arch impingement. The C-1 posterior arch was resected, and after the surgery, the patient indicated that the intolerable pain had disappeared. In conclusion, in patients with OPLL and a kyphotic cervical spine, the authors propose that the pathognomonic protruded position is valuable for estimating disrupted compensatory mechanisms at the upper cervical junction.
authors.affiliation: Departments of Neurological Surgery and.
authors.forename: Mikinobu
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Norimitsu
authors.initials: N
authors.lastname: Wakao
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kamiya
authors.forename: Aichi
authors.initials: A
authors.lastname: Niwa
authors.forename: Koji
authors.initials: K
authors.lastname: Osuka
authors.forename: Masakazu
authors.initials: M
authors.lastname: Takayasu
mesh_terms: D000328:Adult; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000601:surgery*; D019299:Decompression, Surgical; D006801:Humans; D007738:Kyphosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D017887:Ossification of Posterior Longitudinal Ligament / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D016896:Treatment Outcome