- Most tremors occur in the hands, legs and arms. They also occur in the face, the trunk, the head and the voice of the sleeping individual. Sleep tremors could be a symptom of a neurological disorder. They most often occur in healthy individuals with no other known disorders. Tremors can be caused by the excessive consumption of alcohol or alcohol withdrawal. Sleep tremors can also run in families and can also be caused by overactive thyroid conditions.
The essential tremor is one of the more than 20 types of tremor, according to the National Institute of Neurological Disorders and Stroke Online. Tremors can occur at any age, but onset is most common after age 40. The head is mostly effected, but the tongue, voice, head, legs and trunk are also involved. The head tremor may be interpreted as a "yes-yes" or a "no-no" movement, according to the NINDS Online.
Parkinsonian tremor is described by the NINDS Online as a "pin-rolling" action that effects mostly the hands. This type of tremor can also effect the chin, lips, legs and trunk.
- Sleep myoclonus refers to a sudden involuntary jerking or twitching of a muscle or a group of muscles, according to the National Institute of Neurological Disorders and Stroke Online. Myoclonus twitches sometimes appear alone or in pattern sequences. In some cases, these twitches begin in one area of the body and spread to muscles in other areas, while occuring in an otherwise healthy individual. This form of twitching normally appears during the initial phase of sleep and could be a symptom of a sleep disorder, such as restless leg syndrome.
- Sleep convulsions are involuntary muscle spasms that can last from 30 seconds to two minutes. When an individual is having sleep convulsions, notice which arms or legs are shaking, fever and for a change in consciousness. The use of alcohol or drugs can trigger sleep convulsions. They can signal medical causes including low blood sugar, epilepsy, heart disease or a head injury. If convulsions continue without stopping, seek medical attention.
- Dystonia is a movement disorder that causes dystonic tremors. Individuals of all ages can suffer dystonic tremors, which are painful positions and twisting motions of the body that are caused by involuntary muscle contractions.
REM Behavior Disorder
- Twitching during REM sleep, the phase of sleep where rapid eye movement occurs, could indicate REM behavior disorder, or RBD. Normal REM sleep is when the body is limp with sleep paralysis while the brain is busy processing information. This phase of sleep is also where the strongest dreams occur. Individuals with REM behavior disorder experience violent twitching and muscle spasms during the REM stages, instead of the healthy limp sleep paralysis. Individuals with this disorder do not have the ability for muscle relaxation during REM sleep. Muscles twitch and react as they are acting within the dream.