Central Sleep Apnea Syndrome (CSAS) occurs when breathing either stops (apnea) or is reduced (hypopnea) in persons with unobstructed upper airways.1 As a result of the central respiratory center’s failure to signal to breathe, the person’s breathing is diminished or stops repetitively for 10 seconds or more.
In contrast to Obstructive Sleep Apnea Syndrome (OSAS), where arousals are typically required to terminate the apnea, central apnea-hypopneas generally end gradually, when the signal to breath returns.2
There are four subtypes of CSAS:
- Primary Central Sleep Apnea
- Central Sleep Apnea Due to Cheyne Stokes Breathing Pattern
- Central Sleep Apnea Due to a Medical Condition Other Than Cheyne Stokes
- Central Sleep Apnea Due to a Drug or Substance
Primary Central Sleep Apnea
The cause of Primary Central Sleep Apnea Syndrome (CSAS) is not known, but it is thought to involve overly sensitive oxygen (O2) and carbon dioxide (CO2) sensors and feedback loops.3
Central Sleep Apnea Due to Cheyne-Stokes Breathing Pattern
Cheyne-Stokes breathing is characterized by apneas, hypopneas, or both, alternating with periods of excessive breathing (hyperpneas). This waxing and waning pattern distinguishes Cheyne-Stokes from other forms of CSAS.
Central Sleep Apnea Due to a Medical Condition Other Than Cheyne Stokes
Patients may develop CSAS from brain stem lesions of vascular, neoplastic, or other etiology. Others result from renal dysfunction.
Central Sleep Apnea Due to a Drug or Substance
Numerous drugs give rise to CSAS, including the use of opioid preparations. 4
- Wellman A and D White, “Central Sleep Apnea and Periodic Breathing,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1140-1152.
- Xie A, Rutherford R, Rankin F, et al. Hypocapnia and increased ventilatory responsiveness in patients with idiopathic central sleep apnea. Am J Respir Crit Care Med. 1995;152:1950-1955.
- Wellman A, and D White, “Central Sleep Apnea and Periodic Breathing,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1140-1152.
- Farnery R, Walker J, Cloward T, Rhondeau S. Sleep-disordered breathing associated with long-term opioid therapy. Chest. 2003;123:632-639.