What Is Sleep Apnea?
Sleep apnea is a condition in which you stop breathing while asleep. With sleep apnea, your breathing while you are asleep is interrupted by repeated pauses known as apneic events. The types of sleep apnea include: obstructive sleep apnea, which is the most common form of sleep apnea; central sleep apnea; and mixed (or complex) sleep apnea, which combines the two other types.
Sleep apnea can cause serious health problems. It can increase the risk for stroke, obesity, diabetes, heart attack, heart failure, irregular heartbeat, and high blood pressure. It may also increase the risk for accidents while working or driving, as some people with sleep apnea may fall asleep during those activities.
What Is Central Sleep Apnea?
In CSA, breathing is disrupted regularly during sleep because of the way the brain functions. It is not that you cannot breathe (which is true in obstructive sleep apnea); rather, you do not try to breathe at all. The brain does not tell your muscles to breathe. This type of sleep apnea is usually associated with serious illness, especially an illness in which the lower brainstem -- which controls breathing -- is affected. In infants, central sleep apnea produces pauses in breathing that can last 20 seconds.
Who Gets Central Sleep Apnea?
Central sleep apnea is more common among older adults, especially adults older than age 65. This could be because they may have other medical conditions or sleep patterns that are more likely to cause CSA.Another factor, is being male. Men are more at risk for both CSA and obstructive sleep apnea. Being overweight is a risk factors for OSA but is generally not considered a risk factor for CSA. However, anyone can have any of the types of sleep apnea.
Central sleep apnea is often associated with other conditions. One form of central sleep apnea, however, has no known cause and is not associated with any other disease. In addition, central sleep apnea can occur with obstructive sleep apnea, or it can occur alone.
Conditions that may be associated with central sleep apnea include the following:
- Congestive heart failure
- Hypothyroid Disease
- Kidney failure
- Neurological diseases, such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)
- Damage to the brainstem caused by encephalitis, stroke, injury, or other factors
What Are the Symptoms of Central Sleep Apnea?
The main symptom of CSA is temporary stoppages of breathing while asleep. Although snoring is a very strong symptom of obstructive sleep apnea, snoring is usually not found with central sleep apnea.
Symptoms may also include:
- Being very tired during the day
- Waking up often during the night
- Having headaches in the early morning
- Poor memory and difficulty concentrating
- Mood problems
How Is Central Sleep Apnea Diagnosed?
If you have any of these symptoms of central sleep apnea, or if a family member or bed partner notices that you stop breathing while sleeping, you should talk to your doctor or health care provider.
If your doctor suspects you have central sleep apnea, he is likely to perform a physical exam, take a medical history, and recommend a sleep history. The next step will likely be an overnight sleep study called a polysomnogram. This test is performed in a sleep lab under the direct supervision of a trained technologist. During the test, the following body functions may be monitored:
- Electrical activity of the brain
- Eye movements
- Muscle activity
- Heart rate
- Breathing patterns
- Air flow
- Blood oxygen levels
After the study is completed, the technologist will tally the number of times that breathing is impaired during sleep and then grade the severity of sleep apnea.
How Is Central Sleep Apnea Treated?
If CSA is associated with some other condition, such as congestive heart failure, that condition is treated, if possible.
Some of the more conservative treatments for obstructive sleep apnea would likely benefit people with central sleep apnea as well. Some of these conservative treatments include:
- Losing weight if necessary, and then maintaining a healthy weight
- Avoiding the use of alcohol and sleeping pills, as these items make the airway more likely to collapse during sleep
- Sleeping on your side if you have apneic events when sleeping on your back, possibly using pillows or other devices to keep you in place
- Using nasal sprays or breathing strips to keep air flowing if you have sinus problems or nasal congestion
- Avoiding sleep deprivation
Another treatment is continuous positive airway pressure (CPAP), which is the preferred initial treatment for most people with obstructive sleep apnea. The treatment has been beneficial in people with central sleep apnea, as well. This is especially true of people who have central sleep apnea associated with heart failure.
With CPAP, patients wear a mask over their nose and/or mouth. An air blower forces air through the nose and/or mouth. The air pressure is adjusted so that it is just enough to prevent the upper airway tissues from collapsing during sleep. The pressure is constant and continuous. CPAP prevents airway closure while it is being used, but apnea episodes return when CPAP is stopped or is used improperly. Other styles and types of positive airway pressure devices are available for people who have difficulty tolerating CPAP.
ASV ( Adaptive servo-ventilation) and BPAP (Bilevel positive airway pressure) are other devices which deliver pressurized air.
For patients with moderate to severe central sleep apnea, the FDA has recently approved an implantable device called the Remede System. The small machine is surgically placed under the skin in the upper chest area where it helps stimulate the nerve which moves your diaphragm when you breathe. It monitors your respiratory signals while you sleep and helps restore normal breathing patterns.
Medications can be used under some circumstances.Several different medications aimed at improving CSA include acetazolamide, theophylline, and sedative-hypnotic agents.