How to define complex sleep apnea? How does it relate to central sleep apnea?

Receiving a sleep apnea diagnosis can be concerning and may raise many questions as to what it really means and how it will affect your life. 

In this blog post, we describe two types of sleep apnea (complex and central), and explain how they’re related to each other. This information will be useful to people who want to understand their diagnosis and better manage their symptoms for a better quality of life.

Types of sleep apnea you need to know about

The first thing to understand is that “sleep apnea” is an umbrella term for several sleep disorders that interfere with normal breathing. 

There are three types of sleep apnea: complex, central, and obstructive sleep apnea. 

Of these three types, obstructive sleep apnea or OSA is the most common. It’s estimated that this condition affects approximately 1 billion people all over the world.

Central sleep apnea affects less than 1% of adults over 40 years old in the United States. And 15% of all sleep apnea patients suffer from complex sleep apnea.

It’s very important to know which type of these three disorders you have, because the implications and treatment will vary. Although some of the symptoms are similar (such as daytime fatigue and multiple sleep/ breathing interruptions), each type of sleep apnea needs to be addressed individually.

What is central sleep apnea?

Like other types of sleep apnea, this disorder affects the upper airways, but the problem isn’t mechanical or physiological. In other words, people with this type of sleep apnea don’t experience any narrowing or blocking of their airways.

Instead, this disorder has its root in the central nervous system – hence its name. Specifically, breathing interruptions occur because the brain fails to send messages to the parts of the body that are responsible for correct breathing.

Because of the brain involvement, this form of sleep apnea often coexists with other conditions that also affect the brain or the central nervous system. Risk factors include infections affecting the brain or brainstem, brain tumors, stroke, and cervical or brainstem lesions. 

The use of opioid medications and narcotic painkillers can also increase the chances of developing this disorder, as do obesity, chronic heart failure, and Parkinson’s disease.

What is complex sleep apnea?

This type of sleep apnea has aspects of both OSA and central sleep apnea. 

Although in this blog post we won’t describe OSA in detail, you need to know that this condition often improves when the patient follows CPAP therapy. This involves the use of a Continuous Positive Air Pressure machine, which ensures the airways remain open and oxygen reaches the brain throughout the night. 

However, patients with complex sleep apnea don’t respond well to CPAP therapy, and the symptoms continue even after the airway blockage or narrowing is addressed. 

It’s also possible that someone with OSA develops central sleep apnea after being treated with CPAP, in which case their diagnosis changes to complex sleep apnea. This happens in approximately 2% of all sleep apnea cases. 

Sleep specialists don’t fully understand the mechanism behind this disorder, but they have confirmed that the symptoms are not related to the use of certain medications or to conditions like stroke or heart failure. 

It’s also been found that men -- and those with severe forms of OSA -- are more likely to develop complex sleep apnea after starting CPAP treatment.

Other studies have suggested that this subtype of sleep apnea is more likely to appear in people who suffer from insomnia or who sleep in an environment where there’s an imbalance between carbon dioxide and oxygen levels.

From all this, we can see that although complex and central sleep apnea have different causes, one can give rise to the other. Now, if you’ve been diagnosed with either form of sleep apnea, the question is what can you do to alleviate the symptoms.

Treating central and complex sleep apnea

The top priority of all sleep apnea treatments is to stabilize breathing patterns so that the brain and body get the amount of oxygen they need to function. 

Where the root causes of the disorder are known, treatment will also focus on addressing them. For example, central sleep apnea patients whose condition is caused by narcotic painkillers would have to explore the possibility of taking other medications instead. 

Similarly, a sleep specialist would recommend diet changes and exercise to a patient whose symptoms are linked to obesity.

Central sleep apnea can also be treated using drugs that stimulate breathing, medical devices that are similar to a pacemaker, and CPAP therapy. 

Complex sleep apnea patients may benefit from using tongue stabilizing devices and other types of oral appliances that correct the jaw position to facilitate breathing. 

Patients who are not responsive to CPAP may see some improvement when switching to ASV therapy, or using a BiPAP machine.

As usual, any changes to your current treatment plan must be discussed in advance with your doctor and sleep specialist.