title: Occipitocervical fusion has potential to improve sleep apnea in patients with rheumatoid arthritis and upper cervical lesions.
abstract: METHODS
  Case series.
  
  
  OBJECTIVE
  To analyze factors that contribute to the development of sleep apnea in patients with rheumatoid arthritis (RA) and upper cervical lesions.
  
  
  BACKGROUND
  No large prospective study has analyzed the association between sleep apnea and upper cervical involvement resulting from RA. Furthermore, only 1 report in the literature describes a case of sleep apnea accompanying rheumatoid vertical subluxation of the odontoid process.
  
  
  METHODS
  The authors analyzed 8 consecutive RA patients with upper cervical lesions who underwent occipitocervical (O-C) fusion. The patients were examined with all-night polysomnography before and after surgery. Patients with apnea-hypopnea index values>or=5 were diagnosed to have sleep apnea. O-C2 angles were calculated from cervical radiographs.
  
  
  RESULTS
  All 8 patients were diagnosed as having sleep apnea, and most of their apneic episodes were obstructive in origin. Among the 4 patients with medullary compression, central apneic episodes comprised<or=5% of their respiratory events. Two patients with severe sleep apnea had negative O-C2 angles. Six patients who showed postoperative improvements in their sleep apnea all had positive changes in their O-C2 angles exceeding 5 degrees after surgery. The differences between preoperative and postoperative O-C2 angles were significantly greater in the patients with improvement of sleep apnea than in the patients with worsening sleep apnea.
  
  
  CONCLUSIONS
  All our study patients with RA and upper cervical lesions had obstructive-dominant sleep apnea. Negative O-C2 angles may result in upper airway narrowing, increasing the severity of sleep apnea. O-C fusion with correction of kyphosis at the craniovertebral junction has the potential to improve sleep apnea in RA patients.
authors.affiliation: Department of Orthopaedic Surgery, Matsudo City Hospital, Department of Anesthesiology, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ataka
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tanno
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Miyashita
authors.forename: Shiroh
authors.initials: S
authors.lastname: Isono
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001269:Atlanto-Occipital Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007564:Japan; D007593:Joint Instability / Q000209:etiology / Q000601:surgery; D008875:Middle Aged; D017286:Polysomnography; D011859:Radiography; D016059:Range of Motion, Articular; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D013123:Spinal Fusion; D016896:Treatment Outcome