title: Diagnosis and treatment of ossification of the posterior longitudinal ligament of the spine: report of eight cases and literature review.
abstract: OBJECTIVE
  Ossification of the posterior longitudinal ligament (OPLL) is a common, well-recognized cause of spinal stenosis and myelopathy in Japan. Although also common in whites, especially among the elderly, it has received little scientific attention. We wish to increase awareness of this important cause of myelopathy, and to determine if the clinical characteristics of OPLL are similar in non-Japanese and Japanese patients.
  
  
  METHODS
  The clinical and radiologic features of eight cases of OPLL are presented. These cases combined with 73 non-Japanese cases gathered from the English literature are contrasted with 2,125 Japanese cases of OPLL.
  
  
  RESULTS
  Similarities among non-Japanese and Japanese cases included: (1) male predominance; (2) peak age at onset of symptoms in the sixth decade; (3) clinical presentation, which ranged from asymptomatic to quadriplegia, with progressive or acute onset of neurologic deterioration; (4) greater than 95% localization to the cervical spine, spastic quadriparesis being the most common neurologic presentation; (5) an association with several rheumatic conditions including diffuse idiopathic skeletal hyperostosis (DISH), spondylosis, and ankylosing spondylitis; and (6) neurologic improvement with either conservative or surgical treatment in a significant proportion of patients. Differences between the two groups were minimal and included a higher mean age at onset (although onset in both groups occurred within the sixth decade) and a greater proportion of patients with DISH and with the continuous type of OPLL in the non-Japanese group.
  
  
  CONCLUSIONS
  The clinical characteristics of OPLL are similar in Japanese and non-Japanese patient populations. Increased awareness of this condition, which has potentially devastating neurologic complications, will favorably influence diagnosis, treatment, and outcome.
authors.affiliation: Department of Neurology, Montreal General Hospital, McGill University, Quebec, Canada.
authors.forename: D A
authors.initials: DA
authors.lastname: Trojan
authors.forename: J
authors.initials: J
authors.lastname: Pouchot
authors.forename: R
authors.initials: R
authors.lastname: Pokrupa
authors.forename: R M
authors.initials: RM
authors.lastname: Ford
authors.forename: C
authors.initials: C
authors.lastname: Adamsbaum
authors.forename: R O
authors.initials: RO
authors.lastname: Hill
authors.forename: J M
authors.initials: JM
authors.lastname: Esdaile
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001510:Bed Rest; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007796:Laminectomy / Q000592:standards; D008022:Ligaments; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D009999:Ossification, Heterotopic / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D026741:Physical Therapy Modalities / Q000592:standards; D015995:Prevalence; D044469:Racial Groups; D012307:Risk Factors; D012737:Sex Factors; D013122:Spinal Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003907:Dexamethasone