Central sleep apnea is a rarer condition than obstructive sleep apnea, involving a dysfunction in the brain systems that govern breathing rather than a blockage of the airway. Many patients with central sleep apnea also have some obstructive apnea. In this study, patients were classified as having the central form if they had 10 or more central events an hour, but five or fewer obstructive events.
Central sleep apnea is not the same as obstructive sleep apnea, which is due to a blockage in the airway. Oral appliances are not indicated in the treatment of central sleep apnea.
The symptoms of central sleep apnea are loud snoring, hypersomnolence (excessive daytime sleepiness), and restless sleep. The problem of excessive daytime sleepiness (especially while driving, working or talking) develops slowly over years and is noticeable by friends and colleagues. Hypersomnolence and neurocognitive disturbances stand as a cause for automobile or work-related accidents in sleep apnea patients.
Other symptoms of central sleep apnea include choking or gasping during sleep, unrefreshing sleep, morning headaches, daytime fatigue, personality changes, memory impairment, impaired concentration, poor judgment, mood disturbances, recent weight gain, polyurea, and impotence.
The hypoxic and hypercapnic drives can be impaired by brain stem lesions or by exposure to recurrent hypoxia and hypercapnia and result in central sleep apnea. The stimulus to breathe instead from the cortex and reticular activating system is lost during sleep and the patient stops breathing, the so-called “Ondine’s curse”. Central sleep apnea can also be caused by another rare condition of bilateral diaphragm paralysis which usually occurs as part of a general neuromuscular condition but in some cases can lead to respiratory failure before general weakness is apparent.
The most common and effective treatment option for patients of central sleep apnea is assisted overnight ventilation with external devices such as a rocking bed, or cuirasse. A rocking bed prevents cessation of breathing during sleep by pushing the diaphragm up and down by gravity. Another ventilator device of importance is cuirasse. Cuirasse consists of a small shell that fits around the patient and is connected to an intermittent vacuum pump that draws out the chest wall.