Central sleep apnea is a sleep-related breathing disorder. People who suffer from it experience cessation of the airway during the night, which leads to lower oxygen levels, and can have serious consequences. Central sleep apnea (CSA) is caused by the brain not properly delivering signals to the muscles that control your breathing. It is different than obstructive sleep apnea (OSA) that is caused by some obstruction of the airway.
Central sleep apnea is often connected to some underlying neurological or cardiovascular conditions, and it is more frequent during non-REM sleep. CSA can be an indicator of a severe illness affecting the lower brainstem, a part of your central nervous system that controls breathing patterns.
CSA can increase the risk of diabetes, stroke, obesity, heart-related conditions, and high blood pressure. It also increases the chances of accidents while driving or working, which can endanger your safety.
We’ll look into the common symptoms of central sleep apnea, what causes it, and how doctors diagnose and treat this condition.
Central sleep apnea shares some symptoms with other sleep disorders, especially obstructive sleep apnea. Most commons symptoms are:
- Frequent nighttime awakenings accompanied by shortness of breath
- Difficulty falling or staying asleep (insomnia)
- Shortness of breath is usually relieved by sitting up
- Excessive daytime sleepiness (hypersomnia) and fatigue
- Morning headaches
- Difficulty learning and concentrating
- Mood swings
- Chest pain at night
While snoring is typically a symptom of obstructive sleep apnea, it can be an indicator of CSA. CSA caused by Parkinson’s disease or some other neurological conditions can have other symptoms like:
- Difficulty swallowing
- Change of voice
- Changes in speech patterns
- General weakness
You should consult a medical professional if you experience any of these symptoms, especially shortness of breath that can wake you up, pauses in breathing during sleep, difficulty staying asleep, or excessive daytime drowsiness. Falling asleep can be particularly dangerous if it happens while you are working or driving. Sometimes, it is easier for your partner to notice some of these symptoms, so ask them to observe you for a short period during the night, and watch out for anything unusual.
Causes and Risk Factors
Central sleep apnea is caused by bad communication between the brain and muscles in charge of respiration. Brain’s signals are not interpreted well, or there are no signals, and that leads to hyperventilation (rapid breathing) or hypoventilation (slow breathing). Both of these alter the amount of carbon dioxide and oxygen in our bodies, which then affects the brain stem, a part of our central nervous system that is in charge of breathing.
Several factors can put you at risk of developing central sleep apnea:
- Stroke, structural brainstem lesion or brain tumor. These brain conditions affect the brainstem and its ability to regulate breathing. Any other conditions that affect this part of your brain increase risk of developing CSA.
- Heart disorders. People with congestive heart failure and atrial fibrillation are at a higher risk of developing central sleep apnea.
- Opioid use. Opioid medications can increase the chances of getting CSA as well. Watch out for pain relievers like morphine, codeine, oxycodone, hydrocodone, fentanyl, tramadol, meperidine, and hydromorphone.
- High Altitude. Sleeping at a higher elevation than what you are generally accustomed to can cause central sleep apnea. The symptoms stop when you get back to your usual altitude.
- Sex. Men are more likely to develop CSA than women.
- Age. CSA is more frequent among older people over 65 years old, probably because they have disrupted sleep patterns and other medical conditions that are likely to cause CSA.
- CPAP therapy. Some people who have obstructive sleep apnea can develop central sleep apnea due to the use of continuous positive airway pressure (CPAP) machine. This condition is known as complex sleep apnea because it is the combination of central and obstructive sleep apneas. This problem is solved by the continuous use of a CPAP machine or trying a different treatment of positive air pressure therapy.
Different Types of Central Sleep Apnea
- Cheyne-Stokes breathing. This type of CSA is commonly associated with stroke and congestive heart failure. The condition is identified by the increase and then decrease of airflow and breathing effort. Stopping of airflow can happen during the weakest breathing effort. This type of CSA is primarily observed in many who are 60 or older, it is rarely seen in women, and it doesn’t seem to be inherited.
- Drug-induced apnea. Certain medications such as some opioids like codeine, morphine, and oxycodone can cause irregular breathing patterns and induce central sleep apnea.
- High altitude periodic breathing. When being at a higher altitude, Cheyne-Strokes breathing pattern might occur. Due to changes in oxygen levels with higher elevation, your breathing patterns can vary between hyperventilation and hypoventilation. This condition seems to affect men more, as they are more sensitive to changes in oxygen and carbon dioxide blood levels. Some people will experience symptoms when sleeping at 15,000 feet (about 5,000 meters) or higher, while anyone resting above 25,000 feet (7,600 meters) will experience this condition.
- Complex sleep apnea. This condition appears in some people and is caused by continuous positive airway pressure (CPAP) therapy. It’s called complex because it is a combination of central and obstructive sleep apneas.
- Idiopathic (primary) sleep apnea. This condition appears to be very rare, and its cause is unknown. It mostly affects middle-aged and seniors, and men are more prone to developing this disease. There might be a tendency for inheritance, and some neurological conditions such as Parkinson’s may increase the risk.
- Medical condition induced central sleep apnea. This type of CSA is rare, and it occurs in patients with medical conditions that include kidney and heart problems, and abnormalities in the brainstem.
Central Sleep Apnea vs. Obstructive Sleep Apnea
Central sleep apnea is different than obstructive sleep apnea. OSA is caused by some obstruction in the airway during sleep. Brain signals are standard, and an effort to breath is intact, but the problem is mechanical.
CSA is a condition in which the brain doesn’t emit right signals, so the muscles that are in charge of breathing don’t function the way they are supposed to. There is no effort to breathe, and it results in apnea.
CSA is a lot less common than OSA. It is estimated that around 20% of all people diagnosed with apneas suffer from CSA.
The doctor will review your medical history, medication use, and existing symptoms. They might ask you to keep a sleep diary for a week or two so that they have better insights into your sleeping patterns. You’ll include a series of information in a sleep diary, such as:
- What time you went to bed every night
- What time you got up in the morning
- How many times you woke up during the night
- Whether you feel well-rested after waking up
- If you took naps during the day
- How energized you felt during the day
If your situation is complicated, they’ll most likely refer you to a sleep specialist for further diagnosis. Sleep specialists often collaborate with cardiologists and neurologists, and they’ll require you to stay at their facility for an overnight sleep study called polysomnogram.
Polysomnogram includes a series of tests that measure your brainwaves, breathing and heart rate, airflow and blood oxygen levels, eye movement, muscle activity and snoring. You might have a full or split-night sleep study.
In a split-night sleep study, you are observed during the first half of the night. If central apnea symptoms are persistent, sleep technicians will hook you up to a continuous positive airway pressure machine during the second part of the night. That way, they can track how you respond to the therapy, and adjust it if it’s needed.
Polysomnography will also make it easier for doctors to rule out other sleeping conditions that may have similar symptoms but require different therapy. Sometimes, they’ll order an MRI scan of your brain and heart, to better understand any underlying conditions you might have.
There are several treatment options for CSA, and they might include:
- Lifestyle changes. Some treatments used to treat OSA can benefit CSA patients as well, such as losing weight if necessary, avoiding alcohol and nicotine, sleeping on your side instead of your back, using nasal sprays to treat congestion, avoiding sleep deprivation and sticking to healthy sleeping habits.
- Continuous positive airway therapy. CPAP is usually the initial treatment used for OSA and can be quite useful in treating CSA as well. The treatment includes wearing a nasal or a full face mask that is hooked up to a CPAP machine. It supplies pressurized air, and it prevents your upper airway from closing while you are asleep. It is essential to stick with your doctor’s advice on CPAP therapy, and you should inform them if you have any problems with it.
- Treating associated medical conditions. Treating other diseases that may be affecting your sleep apnea will make the symptoms of CSA improve as well.
- Reducing opioid medication. If it’s your medication that is causing CSA, your doctor may gradually reduce the dosage of that medication.
- Adaptive servo-ventilation (ASV). If the CPAP therapy wasn’t successful, you might be given ASV. Like CPAP, it delivers pressurized air to the patient. But, unlike CPAP, it regulates the pressure during inspiration and expiration on a breath to breath basis. That makes it easier for patients, as they can sometimes have problems breathing out during CPAP therapy. ASV regulates breathing patterns, and it might even deliver a breath if you haven’t inhaled in a certain amount of seconds. ASV is not recommended for people who suffer from symptomatic heart failure.
- Bilevel positive airway pressure (BiPAP). Like CPAP, BiPAP also delivers a continuous flow of pressurized air. But that pressure is lower for breathing out. Unlike ASV, the amount of pressurized air is fixed, rather than variable. BiPAP can also be instructed to deliver a breath if you haven’t taken one in a certain amount of seconds.
- Oxygen therapy. Supplemental oxygen therapy while sleeping might help with central sleep apnea. There are various devices available on the market.
- Medications. Certain medications can be prescribed if you are not responding well to positive airway pressure. They help to stimulate breathing and acetazolamide and theophylline are the most common ones. They can also be used to prevent CSA in higher altitudes.
Central sleep apnea can be a dangerous medical condition if not treated well. If you notice any symptoms, pay a visit to your doctor, and they’ll know what to do. Even if you are not suffering from central sleep apnea, they might discover some other sleep disorders that are causing you problems. They’ll treat you accordingly and help you get a better night’s sleep.