Sleep apneas are sleeping disorders in which severe snoring, restless sleep at night and excessive sleepiness during the day are the characteristic symptoms.
What is a Sleep Apnea?
People with a sleep apnea suffer repeated interruptions to their breathing during sleep. Breathing normally provides a constant flow of air to the lungs; when this is interrupted, the amount of oxygen in the blood decreases. When the oxygen level drops below a certain point (after about ten seconds without breathing), a deep inhalation is triggered, causing the sufferer to awaken briefly. These constant interruptions lead to severely disrupted, unrefreshing sleep.
Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is the most common sleep apnea, accounting for 84% of cases. In OSA, the airflow is blocked when the upper part of the throat becomes narrowed during sleep. The usual cause is excess fat around the neck, structural problems with the nose, jaw or mouth, or weakened throat muscles due to alcohol, smoking or sleeping pills.
Central Sleep Apnea
Central sleep apnea is rare, being diagnosed in only 0.4% of cases. It differs from OSA in that it is not caused by an obstruction of the airway. Instead, people with central sleep apnea have a malfunction in the part of the brain that controls breathing (the brainstem). Periodically, the signal that triggers the chest muscles to inhale is not given; as a result, the sufferer stops breathing temporarily.
Central sleep apnea is usually seen in people with damage to the brainstem caused by, for example, infection, stroke or Parkinson’s disease. Certain drugs, including opiates, barbiturates and benzodiazepines, can also affect the control of breathing during sleep. In some cases, central sleep apnea is idiopathic; that is, there is no detectable cause.
Complex Sleep Apnea
Complex sleep apnea is diagnosed in 15% of cases and is a combination of OSA and central sleep apnea. It occurs when people who have had OSA for a long time begin to develop episodes of central sleep apnea in addition to their OSA.
Sleep Apnea Prognosis
People with a sleep apnea are generally assessed in sleep clinics, using specialized sleep studies (polysomnography) and other tests. There are various treatments for OSA, including lifestyle changes such as losing weight or stopping smoking, use of compressed air through a nasal mask or a dental appliance to keep the airway open, and surgery. In central sleep apnea, medications may be given to stimulate breathing, though the outlook tends to be worse when the apnea is caused by damage to the brainstem.
References:
British Snoring & Sleep Apnoea Association. Central Sleep Apnoeas. Accessed 18-03-10
MedlinePlus. Obstructive Sleep Apnea. Accessed 18-03-10
Morgenthaler TI et al.Complex Sleep Apnea Syndrome: Is It a Unique Clinical Syndrome? Sleep 2006; 29(9): 1203−9.
Disclaimer
The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
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