Sleep Twitches

The twitching phenomenon that happens in the early stage of sleep is called a hypnagogic massive jerk, or simply a hypnic jerk. It has also been referred to as a sleep start. There has been little research on this topic, but there have been some theories put forth. When the body drifts off into sleep, it undergoes physiological changes related to body temperature, breathing rate and muscular tone. Hypnic jerks may be the result of muscle changes. Another theory suggests that the transition from the waking to the sleeping state signals the body to relax. But the brain may interpret the relaxation as a sign of falling and then signal the arms and legs to wake up. Electroencephalogram studies have shown sleep starts affect almost 10 percent of the population regularly, 80 percent occasionally, and another 10 percent rarely.

Muscle movement or twitching also may take place during the Rapid Eye Movement, or REM, phase of sleep. This also is the time when dreams occur. During the REM phase, all voluntary muscular activity stops with a drop in muscle tone, but some individuals may experience slight eyelid or ear twitching or slight jerks. Some people with REM behavioral disorder, or RBD, may experience more violent muscular twitching and full-fledged activity during sleep. This is because they do not achieve muscle paralysis, and as a result, act out their dreams. Researchers think that people with RBD lack neurological barriers that define the different stages of sleep. New research done by the Mayo Clinic and published in the July 2003 issue of Sleep Medicine shows that melatonin can help lessen RBD symptoms.

Resources:

Sleep twitches, or myoclonic jerks, as they are sometimes called, are explained in easily understood language on this website.

Learn more about REM Behavior Disorder, or RBD, and treatment for sufferers.

View information about various sleep disorders such as insomnia, apnea, and narcolepsy.

November 8, 2003