Central sleep apnea (CSA) is a sleep disorder characterized by repeated pauses in breathing during sleep, occurring because the brain temporarily fails to send the proper signals to the muscles that control breathing. This condition differs from obstructive sleep apnea (OSA), where breathing pauses result from a physical blockage in the airway. While CSA itself is rarely a direct cause of death, it significantly increases the risk of serious, potentially life-threatening health complications if left unaddressed.
Understanding Central Sleep Apnea
Central sleep apnea manifests when the brain’s respiratory control centers do not adequately stimulate the breathing muscles during sleep. Unlike obstructive sleep apnea, where the airway collapses despite breathing efforts, CSA involves a lack of respiratory effort altogether. This means the brain temporarily “forgets” to tell the body to breathe, leading to pauses in airflow. These interruptions can occur sporadically or in a cyclical pattern throughout the night.
Several underlying medical conditions and factors can contribute to the development of central sleep apnea. Heart conditions, particularly congestive heart failure and atrial fibrillation, are frequently associated with CSA. Neurological disorders such as stroke, Parkinson’s disease, or amyotrophic lateral sclerosis (ALS) can also impair the brain’s ability to regulate breathing. Additionally, the use of opioid pain medications can affect breathing patterns and induce CSA.
Other potential causes include high-altitude exposure and certain inherited disorders. In some instances, central sleep apnea may emerge during treatment for obstructive sleep apnea with positive airway pressure devices.
How Central Sleep Apnea Impacts the Body
The repeated breathing pauses in central sleep apnea lead to significant physiological changes within the body. When breathing stops, blood oxygen levels can drop, a condition known as hypoxemia, while carbon dioxide levels in the blood can rise. These fluctuations place considerable stress on various bodily systems, particularly the cardiovascular system.
The body’s involuntary reflexes attempt to restart breathing, often by causing brief awakenings or arousals from sleep. This constant cycle of oxygen deprivation and arousal activates the sympathetic nervous system, responsible for the “fight or flight” response. This activation can lead to immediate effects such as an increased heart rate and fluctuations in blood pressure. Over time, this chronic stress on the heart and blood vessels can have damaging effects.
Serious Health Risks
Untreated central sleep apnea can lead to a range of serious health complications. The persistent strain on the cardiovascular system can significantly increase the risk of heart attack and stroke. The sudden drops in blood oxygen and the sympathetic nervous system activation can also trigger or worsen arrhythmias, which are irregular heartbeats.
High blood pressure, or hypertension, is another common outcome of long-term untreated CSA. This elevated pressure puts additional stress on the heart and blood vessels, further increasing the risk of cardiovascular events. For individuals with existing heart or neurological conditions, central sleep apnea can exacerbate their symptoms and accelerate disease progression, potentially leading to more severe outcomes.
Diagnosis and Treatment
Diagnosing central sleep apnea typically involves a polysomnography, commonly known as a sleep study. During this overnight test, various bodily functions are monitored, including brain activity, heart rate, breathing patterns, and blood oxygen levels.
Treatment approaches for central sleep apnea often focus on managing the underlying medical conditions that contribute to it. For instance, optimizing treatment for heart failure can frequently improve CSA symptoms. Reducing or discontinuing opioid medications, if they are the cause, is also a primary intervention.
Mechanical ventilation devices are commonly used to support breathing during sleep. Adaptive servo-ventilation (ASV) is a specialized device that monitors breathing patterns and adjusts air pressure in real-time to stabilize respiration during central apneic events. While continuous positive airway pressure (CPAP) is often a first-line therapy for sleep apnea, it may not consistently control CSA and can sometimes induce it in individuals with obstructive sleep apnea. Bilevel positive airway pressure (BiPAP) machines can be an effective alternative for certain types of CSA, especially those linked to specific medical conditions or for patients who do not tolerate CPAP. In some cases, supplemental oxygen or specific medications may also be prescribed to help stimulate breathing.