Definition & Overview
It is normal for people to experience short breathing pauses while sleeping and this is known as sleep apnea. However, if these pauses are extended for a substantial amount of time, the condition, which is then referred to as Central Sleep Apnea, becomes dangerous, even life-threatening.
In Central Sleep Apnea, the aggravating factor is the brain. When the brain fails to signal the muscles that control breathing, the pauses become longer to the point that they become dangerous. In severe cases, the patient will not be able to breath at all or his/her breathing may become too shallow that the body will fail to receive a sufficient amount of oxygen.
There are two type of sleep apnea: Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA). Most people with sleep apnea experience the latter. While less common, CSA presents more danger. Aside from not breathing during sleep, the condition can result in a variety of complications, such as stroke and heart failure.
Unlike CSA wherein breathing pauses are caused by the brain, OSA pauses are caused by tissue collapsing in the airway, preventing air from passing through. Therefore, CSA is more difficult to treat.
Studies have shown that the majority of OSA patients are also affected by CSA. However, this only becomes apparent once OSA has been treated successfully.
Cause of Condition
The brain controls the muscles used in breathing. When we inhale, the brain sends a signal to the breathing muscles to force air to enter the lungs. In CSA, the brain fails to send that signal. Thus the breathing muscles fail to function.
Fortunately, when the brain detects that the body lacks oxygen, it forces the person to wake up and this effectively resets the breathing rhythm. However, once the person falls asleep again, the same thing happens for up to five times every hour. As a result, people with CSA and OSA feel extreme fatigue due to the lack of sleep.
Six types of Central Sleep Apnea
Drug Induced CSA – Triggered by medications, such as Morphine, Oxycodone, and Codeine
Cheyne-Stokes Breathing CSA - This type of CSA is a result of other medical conditions, such as a stroke or congestive heart failure.
Non-Cheyne Stokes Breathing CSA - CSA that is a result of medical conditions other than heart failure or stroke
High Altitude CSA - People who are at altitudes of above 15,000 ft can experience the condition
Primary CSA - The exact cause of this condition is unknown
Complex CSA - CSA that develops while under treatment for OSA
CSA is more prevalent in males, especially those above the age of 65. People with heart disorders, brain tumor, or have had a stroke are also at a higher risk of developing the condition. Opioid medications, high altitude, and Continuous Positive Airway Pressure (CPAP) devices are also known risk factors. However, CPAP devices may also be effective in treating CSA.
It’s imperative that the symptoms of CSA be recognized as soon as possible. If left untreated, the condition can result in a variety of serious complications such as cardiovascular problems, severe fatigue, and concentration difficulties.
Being awakened by your own snoring is one of the most recognizable signs of CSA. This sudden awakening is a result of the brain forcing the body to wake up because it lacks oxygen. People with CSA experience this several times an hour. The possible results are severe fatigue, mood changes, concentration difficulties, hypersomnia, insomnia, and snoring.
However, the above symptoms are not exclusive to CSA; people with OSA also experience them. A doctor can diagnose sleep apnea by performing a variety of tests to identify the exact condition.
Who to See & Types of Treatment Available
If you experience any of the above symptoms, or your partner notices that you frequently snore loudly, you should see a medical professional qualified to diagnose and treat sleep disorders. However, if the doctor determines that the condition is a result of diseases, such as heart ailments, you could be referred to a specialist such as a cardiologist specialist.
The primary diagnostic procedure performed by sleep specialists when determining the type of sleep apnea is called a polysomnography. This procedure involves analyzing the performance of the heart, lungs, and brain activity during sleep. The test may last the entire night. If you’re diagnosed with OSA during the first half of the night, you’ll need to spend the second half using a CPAP device.
Doctors may also recommend brain and heart imaging tests when diagnosing the condition. In such cases, a neurologist or cardiologist may be consulted, especially if a problem is identified in those two areas.
When treating CSA caused by a disorder, the disorder will need to be treated first. There is a good chance that successfully treating the disorder will also result in the treatment of the condition. If CSA is caused by medications, reducing the medications or replacing them with alternative drugs will likely resolve the condition.
Other than treating the underlying condition and reducing medications, patients will also likely need to use a CPAP device to reduce the symptoms of CSA. In some cases, CPAP alone can treat the condition.
Other than CPAP, doctors may recommend the use of an Adaptive servo-ventilation (ASV) or Bi-level positive airway pressure (BPAP) device, especially if CPAP is unable to deliver the desired results. ASV is similar to CPAP, but is also capable of helping patients who fail to breathe for a predetermined amount of seconds. BPAP also performs the same way, but the pressure it delivers can be adjusted to the needs of the patient.
Other forms of treatment include the delivery of supplemental oxygen while the patient is sleeping and prescribing certain medications such acetazolamide and theophylline to treat the condition.
Aurora RN, Chowdhuri S, Ramar K, et al. The treatment of central sleep apnea syndromes in adults: practice parameters with an evidence-based literature review and meta-analyses. SLEEP. 2012;35:17-40.
Pien GW, Pack AI. Sleep disordered breathing. In: Mason RJ, Broaddus VC, Martin TR, et al, eds. Murray and Nadel’s Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Elsevier Saunders; 2010:chap 79.