Parasomnias

Parasomnias

These disorders are not primarily disorders of sleep and wake states per se. Rather, they are disorders of partial arousal or disorders that interfere with sleep stage transitions.

Arousal disorders

1. Confusional arousals (sleep drunkenness or excessive sleep inertia)

This disorder is an extreme example of the slowness most people feel upon awakening. People with confusional arousals respond poorly to commands or questions, and they have major memory impairment of things that have just happened or happened a short time before. They may exhibit bizarre and strange behavior. Example: picking up a lamp and talking as if it is a phone. Typically occur when someone is aroused from a deep sleep in the first part of the night.

2. Sleepwalking

Sleepwalkers engage in behaviors not usually associated with sleep, such as sitting up in bed, walking about, or even frantic attempts to "escape." These actions are apparently initiated during slow wave sleep. Sleepwalking may end by itself when the sleepwalker returns to bed and goes back to sleep.

3. Night terrors

This disorder is characterized by a sudden arousal from slow wave sleep with a piercing scream or cry and signs of intense fear. The individual usually sits up in bed with eyes open, but is unresponsive to other people or stimuli. If awakened, the patient is confused and disoriented. People usually can't remember the event or have vague, dreamlike images of it. This is usually a disorder of childhood.

Sleep-wake transition disorders

1. Rhythmic movement disorder

This a group of repeated movements (usually in the head and neck) that typically occur immediately before sleep. This disorder is usually found in children age one or younger. The child may lie prone and repeatedly lift the head or entire upper body, and then forcibly bang the head back on the pillow. Or the child may sit against the wall or headboard and repeatedly bang the back of his head against it. Because of this, the disorder is sometimes called "head banging," but it can involve other movements, such as a body rolling or rocking on hands and knees.

2. Sleep starts

Sleep starts are sudden, brief contraction of muscles in the legs, arms, or head, that occur just as people are falling asleep. These hypnagogic jerks are felt by most people at some time, but when they are very strong or frequent they can lead to insomnia.

3. Sleep talking

This problem can be precipitated by emotional stress, fever, or sleep disorders such as night terrors or even sleep apnea. The talk is usually brief and devoid of emotional content, but it can be a long speech or infused with anger and hostility.

4. Nocturnal leg cramps

As the name suggests, these are leg cramps (usually in the calf) that occur spontaneously during sleep. They may last for only a few seconds or as long as 30 minutes. The cramps cause arousal and disturb sleep.

Parasomnias usually associated with REM sleep

1. Nightmares

The sleeper is awakened from REM sleep with frightening dreams.

2. Sleep paralysis

People with sleep paralysis are unable to perform voluntary movements either right before they go to sleep or upon waking in the morning. Sleep paralysis most often lasts for several minutes and then disappears.

3. Impaired sleep-related penile erections

In men, erections are a natural part of REM sleep. When REM- related erections are not present, it indicates a physical cause of impotence.

4. Sleep-related painful erections

Sometimes the erections associated with REM sleep can be so intense as to be painful. This may cause nighttime awakenings during REM sleep, and subsequent sleep loss.