What is Central Sleep Apnea?

Sleep apnea is a condition in which breathing is interrupted by repeated pauses while you are sleeping. 

The most common form of sleep apnea is obstructive apnea:  repetitive episodes of obstruction to air flow into the lungs are caused by the relaxation of soft tissues in the upper airway. 

In central sleep apnea, however, the disruption to breathing is related to brain function.  Unlike obstructive sleep apnea when you cannot move air despite the attempt to breathe, in central sleep apnea the brain is not telling the body to breathe.  This type of apnea is often associated with serious illnesses, especially those in which the lower brainstem that controls breathing is affected.

Who gets Central Sleep Apnea?

Central Sleep Apnea is often associated with other medical conditions.  It can also occur in conjunction with Obstructive Sleep Apnea in which case, it is referred to as "Complex Sleep Apnea".

Conditions that are sometimes associated with Central Sleep Apnea include:

• Congestive Heart Failure

• Stroke affecting the brainstem

• Complications of cervical spine surgery

• Primary hypoventilation syndrome

• Damage to the brainstem caused by encephalitis or trauma

• Neurodegenerative illnesses (Parkinson's disease, Alzheimer's disease, Lou Gehrig's disease)

• Bulbar poliomyelitis

• Radiation of the cervical spine

• Severe arthritis and degenerative changes in the cervical spine

Patients taking narcotics for chronic pain can sometimes experience severe Central Sleep Apnea as these medications can have respiratory depressant effects.

There is also idiopathic central sleep apnea in which the apnea is not associated with another disease.

Congestive Heart Failure and Central Sleep Apnea:  Within certain patient populations the incidence of Central Sleep Apnea may be extremely high. In a recent study of patients with heart failure and left ventricular ejection fraction < 45% it was found that 37% of these subjects had significant Central Sleep Apnea.

What are the signs and symptoms?

How is Central Sleep Apnea diagnosed?

The diagnosis is made by an overnight sleep study. During the study various bodily parameters are monitored, including brain waves, eye movements, oxygen levels, heart rate, and breathing patterns. This data is then interpreted by the physician to make the diagnosis.

What are the treatments available?

If the Central Sleep Apnea is associated with some other condition such as congestive heart failure, treatment of that condition may result in improvement.  If the apnea is related to the respiratory depression effects of narcotics, changes in the medication management of the chronic pain may be helpful.

An exciting recent breakthrough specifically created for the treatment of central and complex sleep apnea is Adaptive Servo Ventilation (ASV).  ASV is similar to the continuous positive airway pressure (CPAP) therapy that is used in the treatment of obstructive sleep apnea but there are significant differences.

ASV is a device that can be placed in your home to treat central and complex sleep apnea. The ASV device works during sleep by gently blowing air from a machine into a mask applied over the person's nose.  When the ASV unit detects significant reductions or pauses in breathing, it intervenes with just enough support to maintain the patient's breathing at 90% of what had been normal for that individual just prior to the decrease in breathing.  When the breathing is stable, ASV provides just enough pressure support to help keep the airway open, providing an approximately 50% reduction in the work of breathing.

ASV is unique in that it continuously adapts to the patient.  It provides just enough support when the patient needs it...in a manner so similar to the patient's own recent breathing pattern and rate that it is not only comfortable, but also unlikely to provoke arousals and additional central apneas.

Our clinic was the first sleep center in Central Texas to offer ASV therapy for patients with central and complex sleep apnea.  Our clinicians and sleep technicians are therefore quite knowledgeable and experienced in the use and management of this new technology.

Additional information regarding ASV therapy is available as a educational handout here:  ASV