Study design: Case series.
Objective: To analyze factors that contribute to the development of sleep apnea in patients with rheumatoid arthritis (RA) and upper cervical lesions.
Summary of background data: 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.
Conclusion: 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.