Definition
Twitching during sleep can result in difficulties in falling and staying asleep, but is often not noticed by the patients themselves. They are characterized by simple, mostly recurring patterns of movement during sleep, which result in repeated waking and reduce the recovery function of sleep. Parasomnias are phenomena that occur during sleep. They do not affect the quality of sleep or the restorative function of sleep. This form of sleep disorder is the activity that a person performs at night from sleep (e.g. twitching).
Causes
The wide range of sleep disorders can have many different causes. Physical and mental imbalance are two possible causes, but often a causal problem cannot be identified. Since many sleep disturbances occur to a lesser extent also with otherwise complaint-free sleeping persons, it can be assumed that such a disturbance, as long as it does not become a load, is a naturally occurring phenomenon.
Especially muscle twitches when falling asleep are not dangerous in most cases. The brain has to process an enormous amount of stimuli every day. It does this through an interplay of inhibiting and activating structures.
During the phase of falling asleep, it can happen that the inhibiting structures have already been shut down, as in a computer, while other parts of the brain are still active and send out movement signals. Magnesium influences the transmission of signals between nerve and muscle. A deficiency can trigger muscle twitches, especially in superficial muscle groups in the arms and legs.
Other causative factors can be a cramp disorder in the brain, a so-called epilepsy, but also diseases of the musculoskeletal system or the nervous structures of the body. Psychological triggers such as depression or anxiety disorders should also be clarified. Often the disorder cannot be traced back to a single cause, but is the result of an interaction of several factors.
Lifestyle, especially insufficient exercise and alcohol and drug consumption, as well as environmental stress or side effects of medication can also influence the development of a sleep disorder. Caffeine consumption or irregular sleeping patterns should also not be neglected as possible causes. Sleep-related rhythmic movement disorders occur primarily in childhood and are often related to environmental stress factors (such as arguments with parents, problems at school) or medically relevant disorders in child development (such as autism or delayed mental development).
In the former case, the disorder can heal spontaneously. Alcohol can have a destructive effect on nerve tracts, especially in the brain. This can lead to feelings of numbness and tingling as well as gait disorders, but can also trigger muscle cramps and weakness.
The brain controls the movement of the muscles by sending or blocking nervous signals via messenger substances. Alcohol has a positive effect on inhibitory messenger substances in the brain and a negative effect on activating ones. Thus, alcohol initially has a cramp-avoiding effect, as it blocks the activating signals, but at the same time it increases the excitability for activating messenger substances.
This is because the body reacts more sensitively to signals when it perceives less of them. This can be well demonstrated by a self-experiment: you go into a dark room and try to get used to the light conditions there in order to recognize something. If the light is suddenly switched on, the brain is automatically flooded with stimuli and you first have to close your eyes.
If the alcohol level now drops, the increased excitability activates nerve cells in the brain, which trigger cramps in the muscles. This phenomenon is called rebound epilepsy and can occur hours to days after the actual consumption. Alcohol is also diuretic, as it blocks a messenger substance in the brain that is normally supposed to limit water excretion via the kidneys.
Due to the increased flow, the body loses not only water, but also important blood salts or electrolytes, such as potassium, sodium and magnesium. These substances are found in varying concentrations in the blood and in the body cells and influence and maintain important bodily functions.Magnesium in particular can lead to muscle cramps in the event of a deficiency, as it has an influence on the transmission between nerve and muscle. It blocks muscle-activating substances, so that a deficiency leads to a permanent tension of the muscle cell.
A lack of sodium can also lead to muscle twitches and in severe cases even to cramps. Sodium is a substance that is important for the transmission of stimuli in the body, especially in the heart, where it influences the transmission of the electrical clock to the muscle cells. If the balance of sodium is disturbed by a deficiency, excitation in the muscle can be triggered more easily and the muscle will cramp.
The negative effects of alcohol consumption on sleep should also not be underestimated. For example, the REM phases, which are important for the body’s recovery, disappear in favor of superficial sleep. This can lead to a worsening of the symptoms.
Intoxicating drugs that affect central nervous structures such as the brain can always trigger sleep disorders. Substances contained in ecstasy, for example, which have a similar chemical structure to amphetamines (i.e. they have a similar effect) can influence the level of messenger substances in the brain and thus trigger muscle twitches, among other things. Nerve cells are connected to each other via switching points, so-called synapses.
By means of messenger substances, excitations can be passed on from one nerve cell to the next. After they have been released, they are taken up again by the nerve cell, as the body likes to save and does not want to reproduce the messenger substances again and again. Amphetamines and similar substances have an inhibitory effect on the reabsorption of the substances used at the site of nerve impulse transmission.
As a result, the nerve cell, if it wants to transmit a signal, must constantly produce new messenger substances that accumulate at the point of transmission and intensify the effect. The decisive messenger here is serotonin: it is prevented from being reabsorbed into the nerve cell, which prolongs its effectiveness. More and more serotonin molecules accumulate in the synaptic cleft (see picture), the excitation lasts longer and one feels happier.
A typical effect is euphoria, as serotonin has a positive effect on mood. If the concentration of effective serotonin exceeds a certain level, it can become dangerous. A so-called serotonin syndrome develops, which is manifested by an increased urge to move, muscle twitching and trembling, confusion or restlessness, palpitations, high blood pressure, increased reflexes and increased sweating.
Not to be underestimated is also the interaction with certain drugs used to treat depression (since serotonin affects mood), and the so-called MAO inhibitors. MAO inhibitors prevent the breakdown of serotonin and similar substances and can therefore have similar effects as described above. Cocaine also affects the pleasure center of the brain in a similar way and can therefore also cause sleep disorders and muscle cramps. Intoxicating drugs can cause muscle tremors, especially during withdrawal. There are the following forms of convulsions during sleep, which are described in more detail below:
- Restless Leg Syndrome
- Periodic movements during sleep
- Nightly calf cramps
- Sleep-related teeth grinding
- Sleep-related rhythmic movement disorders