What is Central Sleep Apnea?

Central sleep apnea (CSA) is a type of sleep disorder that causes your breathing to repeatedly stop and start during sleep. It’s associated with significant complications, including frequent nighttime awakenings, excessive daytime sleepiness and an increased risk of problems associated with the heart and circulatory system.^[1]

Causes of CSA

Breathing is controlled by the autonomic nervous system, a part of the nervous system that unconsciously controls bodily function such as breathing, heart rate and digestion. Under normal circumstances, when the brain senses the need for a breath, it sends signals to the diaphragm and intercostal muscles to contract and relax at regular intervals. In CSA, this process is disrupted because the brain fails to send those signals. CSA may be caused by a number of important factors including:^[2]

• Cheyne-Stokes breathing – a distinct breathing pattern characterized by progressively deeper and faster breaths followed by a gradual decrease that leads to a temporary cessation of breathing (apnea). Most commonly associated with congestive heart failure (CHF) and stroke.
• High altitude periodic breathing – exposure to very high altitudes where less oxygen is available in the air may cause a Cheyne-Stokes type of breathing pattern.
• Complex (mixed) sleep apnea – a combination of both types of sleep apneas: obstructive sleep apnea (OSA) and CSA.
• Medical condition-induced CSA – CSA caused by certain medical conditions that are not associated with the Cheyne-Stokes variety of breathing.
• Idiopathic CSA – CSA caused by an unknown source.
• Drug-induced apnea – certain types of medications, particularly opioids (morphine, Oxycodone, Codeine, etc.) can cause an irregular breathing pattern including an increase and decrease in a regular pattern or a complete, temporary cessation of breathing.

Central Sleep Apnea Symptoms

Symptoms of central sleep apnea include:²

• Loud snoring accompanied by abrupt awakenings, shortness of breath and snorting or gasping for air (witnessed by a partner or bed mate)
• Shortness of breath that’s relieved by sitting in an upright position
• Difficulty staying asleep (one type of insomnia)
• Excessive daytime sleepiness (hypersomnia)
• Difficulty concentrating
• Chest pain at night
• Mood changes
• Morning headaches

Are You at Risk?

The following factors may put you at risk for CSA:²

• Being male
• Being an older adult, especially older than 65 years of age
• Having atrial fibrillation (A-fib) or CHF
• History of stroke, brain tumor or structural brain lesion
• Sleeping in high altitude
• Use of opioids
• Use of continuous positive airway pressure (CPAP) for OSA (sometimes causes CSA)

CSA Diagnosis

Central sleep apnea is diagnosed using a test called a polysomnography, commonly referred to as a sleep study.²

Central Sleep Apnea Treatment

Treatment of CSA may include the following:²

• Addressing coexisting medical conditions – may help resolve CSA.
• Reducing opioid consumption – gradually reducing your dose of this type of medication may help eliminate CSA.
• Using CPAP – usually the first-line treatment for CSA. Involves wearing a mask over your nose while you sleep that’s attached to a hose and small pump that delivers continuous pressure to help keep your airway open.
• Adaptive servo-ventilation (ASV) – sometimes utilized if CPAP is ineffective; instead of continuous pressure used with CPAP, ASV adjusts the amount of pressure with every breath and may also deliver a breath when breathing is paused for a certain amount of seconds.
• Bi-Level Positive Airway Pressure – delivers a higher amount of pressure when you breathe in and a lower amount of pressure when you breathe out. More tolerable than CPAP for some people, especially people with lung diseases like COPD.
• Supplemental oxygen – used during sleep may help relieve CSA.
• Certain medications – medications that stimulate breathing such as acetazolamide (Diamox) and theophylline (Theo-24, etc.) may be helpful for those with CSA.

How CSA Differs from Other Types of Sleep Apnea

We already know that CSA is characterized by a failure of the breathing center in the brain to send a signal to the muscles of breathing to breathe. How does CSA differ from OSA? And how does one wind up with both?

Obstructive sleep apnea – the most common type of sleep apnea – occurs when the throat muscles sporadically relax during sleep causing a partial or complete blockage of the airway. This leads to episodes of hypopnea (abnormally slow/shallow breathing) and complete apnea (cessation of breathing). It differs from CSA because it’s caused by a physical obstruction of the airway and has nothing to do with brain activity and the autonomic nervous system.^[3]

Complex or mixed sleep apnea is a combination of both types of sleep apneas: OSA and CSA. It’s been suggested that some OSA patients treated with CPAP also develop CSA. In fact, in 2006, researchers from the Mayo Clinic conducted a study using 223 OSA patients and found that 15% of them also had CSA. During CPAP treatment their airways were successfully “splinted open and free from obstruction,” but they continued to have difficulty breathing during sleep. The study revealed that their symptoms of OSA shifted to symptoms of CSA while undergoing CPAP treatment for OSA.^[4]

***For more information about central sleep apnea, talk to your primary care provider.

_{[1] Eckert, D. J., Jordan, A. S., Merchia, P., & Malhotra, A. (2007). Central Sleep Apnea: Pathophysiology and Treatment. Chest, 131(2), 595–607. http://doi.org/10.1378/chest.06.2287}

_{[2] Mayo Clinic. Central Sleep Apnea. August 7, 2017.}

_{[3] Mayo Clinic. Obstructive Sleep Apnea. August 2, 2017.}

_{[4] Wang, J., Wang, Y., Feng, J., Chen, B., & Cao, J. (2013). Complex sleep apnea syndrome. Patient Preference and Adherence, 7, 633–641. http://doi.org/10.2147/PPA.S46626}