Breathing-related sleep disorder Health Article

Definition

Breathing-related sleep disorder is marked by sleep disruption caused by abnormal breathing during sleep. The most common complaint of individuals with breathing-related sleep disorder is excessive daytime sleepiness, brought on by frequent interruptions of nocturnal, or nighttime, sleep. A less frequent complaint is insomnia or inability to sleep.

Mental health professionals use the Diagnostic and Statistical Manual of Mental Disorders also known as the DSM to diagnose mental disorders. In the 2000 edition of this manual (the fourth edition, text revision, also known as DSM-IV-TR) breathing-related sleep disorder is listed as one of several different primary sleep disorders. Within the category of primary sleep disorders, it is classified as one of the dyssomnias, which are characterized by irregularities in the quality, timing, and amount of sleep.

The DSM-IV-TR lists three types of breathing-related sleep disorder: obstructive sleep apnea syndrome (the most common type); central sleep apnea syndrome; and central alveolar hypoventilation syndrome.

Description

The most common feature of any breathing-related sleep disorder is interruption of the person's sleep leading to excessive daytime sleepiness. When the regular nighttime sleep of individuals is frequently interrupted, sleepiness at other times of the day is the usual result. People with breathing-related sleep disorder often find that they feel sleepy during such relaxing activities as reading or watching a movie. With extreme cases, the person may feel so sleepy that he or she falls asleep during activities that require alertness, such as talking, walking, or driving.

Other people with breathing-related sleep disorder report having insomnia, or the inability to sleep. Patients also find that their sleep does not refresh them; they may awaken frequently during sleep, or have difficulty breathing while sleeping or lying down.

The two sleep apnea syndromes that are listed as subtypes of breathing-related sleep disorder are characterized by episodes of airway blockage or stopping of breathing during sleep. Sleep apnea is potentially deadly. The other type of breathing-related sleep disorder, central alveolar hypoventilation syndrome, is distinguished from the other two subtypes by the fact that the reduced oxygen content of the blood is caused by shallow breathing. The alveoli, which are the tiny air sacs in the lung tissue, are not able to oxygenate the blood efficiently because the person is not breathing deeply enough. Shallow breathing often occurs when people are awake and is common in severely overweight individuals.

Causes

Many persons with the obstructive sleep apnea syndrome subtype of breathing-related sleep disorder are overweight. The symptoms often grow worse as the person's weight increases. Persons who have obstructive sleep apnea and are not overweight often have breathing passages that are narrowed by swollen tonsils, abnormally large adenoids, or other abnormalities of the various structures of the mouth and throat.

Central sleep apnea syndrome is often associated with cardiac or neurological conditions affecting airflow regulation. It is a disorder that occurs most frequently in elderly patients.

Patients diagnosed with central alveolar hypoventilation syndrome experience a breathing impairment related to abnormally low arterial oxygen levels.

Symptoms

Obstructive sleep apnea syndrome, which is the most common type of breathing-related sleep disorder, is marked by frequent episodes of upper-airway obstruction during sleep. Patients with this syndrome alternate between loud snores or gasps and silent periods that usually last for 20–30 seconds. The snoring is caused by the partial blockage of the airway. The silent periods are caused by complete obstruction of the airway, which makes the patient's breathing stop.

Obstructive sleep apnea syndrome is also common in children with enlarged tonsils. The symptoms of any breathing-related sleep disorder in children are often subtle and more difficult to diagnose. Children under five are more likely to demonstrate such nighttime symptoms as apnea and breathing difficulties. Children over five are more likely to demonstrate such daytime symptoms as sleepiness and attention difficulties.

Persons with central sleep apnea syndrome experience periods when the oxygenation of blood in the lungs temporarily stops during sleep; but they do not suffer airway obstruction. Although these patients may snore, their snoring is usually mild and not a major complaint.

Central alveolar hypoventilation syndrome is characterized by excessive sleepiness and insomnia.

Demographics

The majority of patients with the obstructive sleep apnea type of breathing-related sleep disorder are overweight, middle-aged males. Adult males are two to four times as likely as adult females to experience obstructive sleep apnea syndrome. Among children the male: female ratio is 1:1.

Central sleep apnea syndrome is most common in the elderly.