Parasomnias

5. REM sleep-related sinus arrest

This is a rare disorder in which the heart will periodically stop beating during REM sleep. Heart stoppages can last up to nine seconds before starting again. This is different from cardiac arrest caused by sleep apnea.

6. REM sleep behavior disorder

In this disorder, the usual REM-associated muscle paralysis is absent, so that people act out the dreams they are having. Punching, kicking, leaping, and running from the bed are common.

Other parasomnias

1. Sleep bruxism

Grinding or clenching teeth during sleep. The sound of grinding teeth can be unpleasant to others who hear it and can cause excessive tooth wear in the individual. It can also lead to jaw pain and headaches while awake.

2. Sleep enuresis (bedwetting)

Urination at night is found in every infant, but as children are toilet trained, they become more able to control their bladder at night. Usually, though, regular bedwetting disappears after the age of five. It is estimated that regular bedwetting occurs in 10 percent of 6-year-olds, 5 percent of 10-year-olds and 3 percent of 12-year-olds. When there are no other neurological, psychiatric, or urological problems that may cause bedwetting, it is called "primary enuresis." There is evidence that primary enuresis is hereditary.

3. Sleep-related abnormal swallowing syndrome

People with this disorder have inadequate swallowing of their saliva while sleeping. Saliva builds up in the mouth, then flows down the throat and is breathed into the lungs. The sleeper wakes up choking and coughing.

4. Sudden unexplained nocturnal death syndrome

This syndrome is typified by sudden death in healthy young adults while they sleep. Neither clinical history nor autopsy provides an explanation for death. The first signs are labored breathing, gasping, and choking, but the disorder is not sleep apnea. Fibrillation (spasm) of the heart muscle has sometimes been detected. Southeast Asian men between 25 and 44 years of age are most often the victims of this disorder.

5. Primary snoring

Primary snoring is loud upper airway breathing sounds without signs of sleep apnea or diminished breathing.

6. Infant sleep apnea

Central or obstructive apneas during sleep in infants. Premature infants are more at risk for this disorder than infants born at term. Infants born before 31 weeks of gestation have about a 50 to 80 percent chance of developing apnea, whereas 7 percent of infants born at term have apnea.

7. Congenital central hypoventilation syndrome

Due to a failure of the automatic control of breathing, not enough air is pulled into the lungs. It is usually worse during sleep than during wakefulness. It usually gets better over 6 to 12 months, although children may have to be hospitalized when they get colds or flus until they are four or five years old.

8. Sudden infant death syndrome

This is an unexplained sudden death during sleep for which there is no adequate explanation. The cause is still a mystery , although risk factors include laying an infant on its stomach, respiratory infections, being one of a multiple birth, or being born to a substance abusing mother.

9. Benign neonatal sleep myoclonus

This is a jerking of the limbs and trunk, or repetitive stretching. The disorder is rare but harmless. The cause is not known.