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Central Sleep Apnea


Kingman P. Strohl

, MD, Case School of Medicine, Case Western Reserve University

Reviewed/Revised Oct 2022

Central sleep apnea (CSA) is a heterogeneous group of conditions characterized by changes in ventilatory drive without airway obstruction. Most of these conditions cause asymptomatic changes in breathing pattern during sleep. The diagnosis is based on clinical findings and, when necessary, confirmed by polysomnography. Treatment is supportive.

General references

  • 1. Donovan LM, Kapur VK: Prevalence and characteristics of central compared to obstructive sleep apnea: analyses from the sleep heart health study cohort. Sleep 39(7):1353-9, 2016. doi: 10.5665/sleep.5962. PMID: 27166235; PMCID: PMC4909617.

  • 2. McLaren AT, Bin-Hasan S, Narang I: Diagnosis, management and pathophysiology of central sleep apnea in children. Paediatr Respir Rev 30:49-57, 2019. doi:10.1016/j.prrv.2018.07.005

Pathophysiology of Central Sleep Apnea

Unlike with obstructive sleep apnea Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , in which airway obstruction restricts airflow, central sleep apnea (CSA) is caused by alterations in respiratory drive, which during sleep is highly dependent on carbon dioxide levels. Two mechanisms are distinguished:

  • Hypoventilation-related CSA: Decreased ventilatory drive causes transient decreases and/or pauses in respiration.

  • Hyperventilation-related CSA: Increased ventilatory drive during sleep leads to hypocapnia which causes a compensatory fall in ventilation that, if abnormally prolonged, leads to recurrent central apnea with arousals.

Hypoventilation-related CSA usually occurs in patients with a central nervous system or neuromuscular disorder that directly impairs ventilation, resulting in high CO2 levels (hypercapnia). Rarely, patients have an impaired chemoreceptor response to hypercapnia (primary alveolar hypoventilation).

Paradoxically, most CSA involves periods of hyperventilation. Transient increases in ventilation for any reason may overshoot the target carbon dioxide level, causing hypocapnia. In most people, compensatory mechanisms restore normal ventilation despite the hypocapnia. In patients with CSA, compensatory mechanisms do not respond quickly enough, and the hypocapnia causes periods of hypoventilation and/or apnea resulting in hypercapnia. Patients may cycle periodically between hyper- and hypoventilation, as in Cheyne-Stokes breathing, in which patients have brief periods of apnea followed by progressively faster and deeper breathing, which then becomes slower and shallower until they become apneic again and repeat the cycle.

Disturbed ventilation occurs primarily during sleep because during wakefulness there are additional external stimuli for respiration.

Etiology of Central Sleep Apnea

Congenital central hypoventilation syndrome (Ondine curse) is a rare form of idiopathic CSA manifesting in neonates, in some cases associated with Hirschsprung disease Hirschsprung Disease Hirschsprung disease is a congenital anomaly consisting of a failure of neuronal colonization (and thus a failure of innervation) of the lower intestine, usually limited to the colon, resulting... read more Hirschsprung Disease . A mutation in the PHOX2 gene is responsible for 80 to 90% of cases. This mutation produces variable phenotypes. Clinically evident cases are inherited in a dominant pattern. Sleep hypoventilation can be found in the parents.

An extremely rare condition that can cause CSA is a syndrome of Rapid-Onset obesity (marked weight gain in < 1 year) with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD); cause is multifactorial. Patients present in their second or third decade, often after a stress such as infection or surgery.

Symptoms and Signs of Central Sleep Apnea

Central sleep apnea may be asymptomatic, detected by caretakers or bed partners who notice long, quiet respiratory pauses and shallow breaths followed by hyperpnea, or restless sleep.

Diagnosis of Central Sleep Apnea

  • Clinical evaluation

  • Often polysomnography

To diagnose central nervous system causes of apnea with hypercapnia, brain or brain stem imaging may be indicated. Arterial blood gases and bicarbonate levels during wakefulness are helpful to distinguish hypercapnic from hypocapnic pathophysiology.

Treatment of Central Sleep Apnea

  • Treatment of cause

  • Supportive care

For patients who have CSA and Cheyne-Stokes breathing, supplemental oxygen may decrease apneic and hypopneic episodes; positive airway modalities have been used, but efficacy is not clear.

Acetazolamide, which causes metabolic acidosis and stimulates respiration, is effective for CSA caused by high altitude and is useful in some patients with heart failure.

Electrical pacing of the diaphragm, typically done by transvenous phrenic nerve stimulation, is an option, such as for children > 2 years with congenital central hypoventilation syndrome, or for adults with symptomatic recurrent CSA. Programmable phrenic nerve or diaphragm stimulation systems can produce a rhythmic breathing pattern that stabilizes tidal volume, airflow, and oxygenation, entrains breathing during sleep, and potentially alters disease progression (2 Treatment references Central sleep apnea (CSA) is a heterogeneous group of conditions characterized by changes in ventilatory drive without airway obstruction. Most of these conditions cause asymptomatic changes... read more ).

Treatment references

  • 1. Dempsey JA: Central sleep apnea: misunderstood and mistreated! F1000Res. 8:F1000 Faculty Rev-981, 2019. doi: 10.12688/f1000research.18358.1

  • 2. Schwartz AR, Sgambati FP, James KJ, et al: Novel phrenic nerve stimulator treats Cheyne-Stokes respiration: polysomnographic insights. J Clin Sleep Med 16(5):817–820, 2020. doi: 10.5664/jcsm.8328

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

Drugs Mentioned In This Article

Drug Name Select Trade
Dolophine, Methadose
Diamox, Diamox Sequels
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