Central sleep apnea (CSA) is a form of sleep-disordered breathing that occurs when the brain fails to send regular signals to the breathing muscle (diaphragm) during sleep. As a result, breathing is either not attempted or becomes more shallow than normal. This is very different than the more common obstructive sleep apnea, where the body tries to breathe but the airway remains closed or partially obstructed.
In a healthy patient (without sleep apnea), the brain signals the breathing muscle (diaphragm) to contract at regular intervals. The signal to breathe travels from the brain stem, down the phrenic nerve, and then to the diaphragm, causing a contraction. This contraction of the diaphragm pulls air into the lungs.
For patients with central sleep apnea, the brain fails to send regular signals to the diaphragm. This is usually because the brain has a delayed response to sensing levels of carbon dioxide (CO2) in the blood stream1. This delay in CO2 response causes an extended “pause” of breathing, ranging in duration from roughly 10 to 40 seconds. An episode may result in:
These events can happen multiple times per hour – sometimes as frequently as once per minute. However, these sleep disturbances are often not enough to fully wake the patient. A patient’s sleep partner may actually be more likely to identify the breathing disorder than the patient himself/herself!
An online discussion of central sleep apnea prepared by experts at Minnesota’s Mayo Clinic breaks the disease down into five types:
Many patients with CSA also have heart disease, especially heart failure. Within this population, patients with CSA are at increased risk for hospitalizations and even death.
The symptoms of central sleep apnea are for the most part the same as those of obstructive sleep apnea. They include chronic fatigue, daytime sleepiness, morning headaches and restless sleep. But if the cause is a neurological disease, the CSA sufferer may also experience difficulty swallowing, voice changes, and an overall sense of weakness and numbness. A thorough sleep study with polysomnography will show whether the lapses in breathing result from airway blockage or irregular breathe signals from the brain. Many patients with CSA also have heart disease, especially heart failure. Within this population, patients with CSA are at increased risk for hospitalizations and even death.
Central sleep apnea is diagnosed by performing an overnight sleep study. Equipment that measures airflow, oxygenation, movement of the abdomen or chest, sound (i.e. snoring), and a variety of other parameters will be used to determine whether someone has a sleep-breathing disorder. This evaluation is often done in a sleep lab.
Treatment options for Central sleep apnea include:
Check out these resources for more information on central sleep apnea: