Sleep-Wake Transition Disorders

Sleep-wake transition disorders cause difficulties in making the transition from waking to slumber, or from one sleep stage to another. The best-known transition disorder is so common that most people don't even consider it to be one: sleep talking.

Sleep talking can occur at any point in the slumber cycle. The lighter the sleep, the more intelligible the speech. During the early stages of the cycle, people may have entire conversations while asleep. In deeper slumber, somniloquy may be restricted to moans and gibberish.

Popular myth associates sleep talking with dreams. While it is possible to talk while dreaming, it isn't as likely as at other stages of slumber. During dreams, our body undergoes temporary paralysis: a safety mechanism designed to prevent us from acting out our dreams and hurting ourselves. This paralysis usually (but not always) includes the jaw and speech mechanisms.

People who talk while asleep have no awareness that they are talking, and often speak in an emotionless tone. Anxiety disorders, stress, and fevers are often responsible for the disorder. Somniloquy is not generally considered a serious problem unless other disorders, such as somnambulism and apnea, are involved.

Somniloquy can be very bothersome to other family members. Here are a few tips to help reduce nighttime chatter:

Rhythmic movement disorder is very common in infants and young children. The child may engage in headbanging, headrolling, bodyrolling or bodyrocking just before falling asleep. Over sixty percent of nine-month-old infants experience it to some degree. By age four, only eighteen percent of children persist in bedtime rhythmic movements.

Nocturnal leg cramps are sudden cramps in the leg that wake people up. The cramp is most often in the calf, but can also be in the soles of the feet. The condition becomes more common as people age: over seventy percent of Americans over age fifty have occasional nocturnal leg cramps.

The cramps may last between mere seconds to as many as ten minutes, and the soreness can linger for longer. Heavy exercise before bedtime appears to increase the chances of leg cramps. Nocturnal leg cramps are not to be confused with restless leg syndrome or periodic limb movement disorder.

Myoclonus (also known as sleep starts) are brief involuntary muscle twitches that often occur as people fall asleep. The sudden twitch startles many people out of sleep. Most people experience myoclonus at one time or another. Hiccups are another type of myoclonus.

WebMD (2007). Sleep Disorders: Parasomnias. Retrieved July 5, 2007, from the WebMD Web site: http://www.webmd.com/sleep-disorders/guide/parasomnias.