Cheyne-Stokes respiration is a variety of central sleep apnea that is characterized by the cyclical weakening and strengthening of the breath. Different from the more common obstructive sleep apnea – in which breathing is inhibited by a physical obstruction of the airway – central sleep apnea occurs when the brain fails to send messages to the respiratory muscles instructing them to breathe. Altogether, only about five percent of all sleep apnea patients suffer from a central sleep apnea.
Generally, Cheyne-Stokes respiration results from damage to the respiratory system. It most often affects those who have suffered stroke or congestive heart failure, but can also occur following injury to the brain, and can even be triggered by exposure to high altitudes. Episodes of Cheyne-Stokes consist of repeating cycles of abnormal respiration, each lasting between approximately 45 seconds and three minutes. During each cycle, the patient's breathing grows strong and then subsequently weakens. At times, this weakening – also known as hypopnea – progresses to a temporary but complete cessation of respiration, or apnea.
As with all forms of sleep apnea, Cheyne-Stokes respiration can negatively affect the quality of a patient's sleep. Of course, the degradation of one's ability to rest at night can carry over to the realm of waking life. As such, sufferers of Cheyne-Stokes respiration might experience daytime fatigue, disorientation, and moodiness. In some cases, however, sufferers are totally unaware of their condition, and can potentially remain so unless a second party happens to witness a Cheyne-Stokes episode.
Perhaps more grave is the potential of Cheyne-Stokes respiration to aggravate heart difficulties that may have initiated the disorder in the first place. When normal respiratory function is interrupted, oxygen pressure in the blood drops – a phenomenon known as hypoxemia. In the absence of sufficient oxygen pressure, the cardiac system's ability to pump blood to the heart is impaired. This condition, called diastolic dysfunction, can lead to arrhythmia, or abnormal heartbeat, which can in turn bring on further heart disease and stroke.
Those who suspect they may suffer from Cheyne-Stokes respiration should consult a physician for diagnosis. As with any type of sleep apnea, the process of diagnosing Cheyne-Stokes typically requires the patient to sleep under observation. During this period, doctors might apply a battery of tests that monitor brain, cardiac, and respiratory systems for signs of abnormality.
Once Cheyne-Stokes is diagnosed, physicians may seek to treat the underlying condition causing the disorder. Addressing a patient's heart difficulty, for instance, may cause Cheyne-Stokes to resolve. In other cases treatment might include the use of devices to regulate breathing patterns and oxygen levels, and maintain open airways.