What is central sleep apnea?

Central sleep apnea (CSA) is a breathing disorder that causes your body to decrease or stop the effort of breathing during sleep. It is usually caused by an issue in the brain or heart. Certain medications (like pain medications) can cause this breathing pattern too. It is different from obstructive sleep apnea (OSA) because the problem is not caused by a blockage of the airway. Central sleep apnea is less common than obstructive sleep apnea.

The brain and heart normally interact to direct, monitor, and change the amount of air that we breathe. The problem in CSA is that the brain does not send appropriate signals to breathe. CSA syndromes in adults are divided into these five categories:

Primary CSA

This breathing pattern consists of repeated periods of time where there is no effort to breathe. As a result, there is little to no airflow. The cause is unknown.

Cheyne-Stokes breathing pattern

This breathing pattern is rhythmic with a steady increase (crescendo) of breathing effort and airflow followed by a decrease (decrescendo) and then sometimes an absence of effort and airflow. This is associated with heart failure, stroke, and possibly kidney disease.

Medical condition not Cheyne-Stokes

This is when central apnea occurs due to medical conditions without the typical pattern of Cheyne-Stokes breathing. It is caused by heart and kidney problems. It may also result from a problem in the base of the brain where breathing is controlled.

High-altitude periodic breathing

This is seen when sleeping at altitudes higher than about 15,000 feet. The breathing pattern is similar to Cheyne-Stokes breathing pattern. The difference is that there is no history of heart failure, stroke, or kidney failure. It often improves as the altitude decreases. The cycle time (the time from one breath to another) also tends to be shorter.

Due to drug or substance

This breathing pattern can vary – from a regular increasing and decreasing respiratory effort to something that is quite irregular. Sometimes there are elements of obstruction such as the breathing that is seen in OSA. Medications most associated with this central sleep apnea pattern are in the opioid category – such as prescription pain medications or illicit substances such as heroin.

What are symptoms of central sleep apnea?

Many people with CSA have the following problems:

Disrupted sleep with frequent awakenings
Difficulty falling asleep
Daytime sleepiness

Other problems often seen include the following:

Pauses in breathing during sleep
Waking up short of breath

A bed partner often can tell if you stop breathing during sleep.

Many people with CSA are sleepy during the day. They find that they are still tired even after a nap. When you stop breathing, your body wakes up. It happens quickly so you aren’t aware of it. This disrupts your sleep. You can stop breathing hundreds of times in one night. This can make you feel very tired the next day.

The medical conditions that cause CSA can also worsen the problems with sleeping and daytime sleepiness.

What are risk factors for central sleep apnea?

Risk factors vary depending on the subtype of CSA.

Primary CSA

Not known, but it appears to be quite rare and occurs in the middle-aged or elderly. Men seem to be affected more than women. There may be a tendency for inheritance. Some neurological conditions may increase the risk. These include Multi-System Atrophy and Parkinson disease.

Cheyne-Stokes breathing pattern

Occurs mainly in men aged 60 or older. It is seen in 25% to 40% of men with chronic congestive heart failure. It is also found in 10% of men who have had a stroke. It is rarely seen in women and does not appear to be inherited.

Medical condition not Cheyne-Stokes

Occurs rarely in patients with a variety of medical conditions. These include heart or kidney problems and abnormalities of the base of the brain where breathing is regulated.

High-altitude periodic breathing

Not known, but it appears to be more common in men. This is because men are more responsive to changes in the level of oxygen and carbon dioxide in their blood. This responsiveness is thought to be partially inherited. Some people sleeping at altitudes higher than 15,000 feet (about 5,000 meters) will have this disorder. Anyone sleeping above 25,000 feet (about 7,600 meters) will be affected.

Due to drug or substance

Appears to occur in those who are taking opioids. The risk for central sleep apnea seems to increase as the dosage of opioids increases. Studies have looked at chronic opioid use (use longer than three months) but it is unclear if short-term opioid use carries the same risks. There are no other characteristics known.

How to diagnose central sleep apnea?

Sleep doctors have training and expertise in this area. The doctor will review your medical history and symptoms. In the case of high-altitude periodic breathing, the detailed history alone should be enough to detect the problem. If needed, the doctor will schedule you for a sleep study.

Most of the causes of CSA are serious conditions that should be evaluated and treated. A sleep doctor can put together a treatment plan just for you. First, she must evaluate the causes of CSA and look for other conditions that create similar problems with sleeping. These include the following:

Another sleep disorder
A medical condition
Medication use
A mental health disorder
Substance abuse

The doctor will need to know your symptoms and how long you have had them. She will also want to know if your symptoms began at the same time as other medical problems or when you slept at a high altitude.

Get information from those who sleep with you or have seen you sleep. This includes spouses, relatives, friends, teammates, and roommates. You will also need to provide a complete medical history.

Keep a sleep diary for two weeks. Include the following information:

What time you went to bed each night
What time you got up in the morning
How many times you woke up during the night
Whether you felt rested when you woke up
If you took naps during the day
Whether you felt sleepy or rested throughout the day

The sleep diary will help the doctor see your sleeping patterns. This information gives the doctor clues about what is causing your problem and how to correct it.

If your doctor thinks that you have a problem with breathing during sleep, you will need to have a sleep study. This study is called polysomnography. It will chart your brain waves, heartbeat, and breathing as you sleep. It will also record how your arms and legs move. This will reveal if you have CSA. It will also show how bad the problem is.

If you have CSA, you may be asked to return for a second polysomnography. This visit will include a CPAP titration study. You will be given positive airway pressure (PAP) treatment as you sleep.

How to treat central sleep apnea?

PAP is the treatment most often used for CSA. It is delivered through a mask that you wear over the nose alone or the nose and mouth. The air gently blows into the back of the throat. This keeps the airway open so you can keep breathing as you sleep.

The amount of air pressure needed is different for each person. A CPAP study will show what level is right for you. Often a variation of PAP, called BPAP (bilevel positive airway pressure), is used.

A thorough evaluation and treatment of underlying medical conditions needs to be done. Heart failure or kidney failure needs specific treatment. Stroke may require special care such as rehabilitation and a careful assessment of your risk of having another stroke.

In the case of high-altitude periodic breathing, no specific treatment may be needed but other problems that occur at high altitudes may need to be addressed. Some of these may respond to medication. Others require avoiding high altitudes and are often reversible by descending to a lower altitude.

In the case of CSA due to drug or substance, a change of medication or discontinuation of the medication or substance may be needed.

Some patients with CSA may be treated with phrenic nerve stimulation. The implanted device stimulates the nerve that sends signals to the diaphragm to stimulate breathing.