Twitching In Rem Sleep: What Does It Mean?

Sleep is divided into non-rapid eye movement (non-REM) and rapid eye movement (REM) sleep. Involuntary twitches commonly take place during REM sleep, which is often symptomatic of chronic disorders. However, the gold standard method to measure REM sleep, polysomnography, is expensive and impractical. As such, researchers have been working on developing a cost-effective method to measure REM sleep. One study found that finger twitches are more frequent in REM sleep than in non-REM sleep, suggesting that a finger-mounted device could be used to measure REM sleep.

Twitching during REM sleep is more common than during non-REM sleep

Twitching during sleep is a common phenomenon known as a hypnic jerk, sleep start, or myoclonus twitch. These involuntary muscle contractions can occur as people fall asleep or while they are sleeping. While hypnic jerks can happen to anyone, they are more common during the transition between wakefulness and sleep, or what is known as hypnagogia.

During sleep, the body typically goes through different stages, including non-rapid eye movement (non-REM) sleep and rapid eye movement (REM) sleep. REM sleep is characterised by rapid eye movements, skeletal muscle inhibition, and cortical activation similar to wakefulness. It is believed to be important for memory consolidation and development.

Research has found that twitching is more frequent during REM sleep than during non-REM sleep. A study conducted by Reiter et al. (2020) used a finger-mounted device to measure finger twitches in 18 healthy adults. The results showed that finger twitch density was greater during REM sleep compared to non-REM sleep. Each sleep stage had a unique finger twitch density, except for REM and stage N1 sleep, which were similar. Additionally, finger twitch density was greater in late REM sleep than in early REM sleep.

The study also found that as sleep progressed, the difference between finger twitch densities in REM and non-REM sleep became more pronounced. This suggests that twitching during REM sleep becomes more distinguishable from non-REM sleep as the night goes on.

While the exact cause of hypnic jerks is not fully understood, they are generally considered harmless and not a cause for concern. However, if they cause distress or are accompanied by other symptoms such as incontinence, injury, pain, or confusion, it is recommended to consult a doctor.

Twitching is associated with dreams

REM sleep is characterised by rapid eye movements, skeletal muscle inhibition, and cortical activation similar to wakefulness. Researchers have consistently reported elevated levels of twitching in the distal muscles of both animals and humans during REM sleep.

A study by Reiter et al. (2020) found that finger twitch density was greater in REM sleep than in non-REM sleep. The study also found that finger twitch density was greater in late REM sleep than in early REM sleep. The results suggest that finger twitching in REM sleep is distinguishable from finger twitching in most other sleep stages and increases as sleep progresses.

Another study by Chiaro et al. (2016) found that hypnic jerks occur randomly and can affect people of all ages. The researchers also found that 60-70% of individuals experience hypnic jerks, usually just as they are about to fall asleep. However, people who experience them do not usually have them every time they sleep.

Hypnic jerks are a type of sleep myoclonus

Sleep myoclonus is not a disease but a symptom of several different conditions and can also happen without a known cause. It is more common in childhood but can continue into adulthood. Newborn hiccups are a form of myoclonus. In infants, benign sleep myoclonus manifests as repetitive twitches in the arms, legs, or torso while the infant sleeps.

There are two types of myoclonus: physiologic and pathologic. Physiologic myoclonus involves quick muscle twitches followed by relaxation, such as sleep starts. Pathologic myoclonus involves contractions that begin in one part of the body and spread to other muscles in other areas.

The symptoms of sleep myoclonus are difficult to miss and can include shaking, spasms, or contractions. They can be localised to one part of the body or occur all over the body, and can vary in intensity and frequency. Sleep myoclonus can be triggered by external stimuli such as noise, movement, or light.

While the exact cause of sleep myoclonus is unclear, researchers have several theories. One primary theory relates to sleep atonia, the natural process in which muscles become paralysed as a person falls deeper into sleep. During sleep atonia, brain signals that activate movements when a person is awake begin to shut down for the night. Occasionally, a brain signal volleys with electricity, resulting in a muscle spasm.

In some cases, sleep myoclonus occurs alongside other symptoms of nervous system disorders. In adults, it may be triggered by drug use, stroke, neurological disease, trauma, kidney or liver failure, infection, or cancer.

While sleep myoclonus is usually benign and does not require treatment, it can indicate an underlying health condition in some cases. If it interferes with sleep or a person's quality of life, it may be treated with medication such as Xenazine (tetrabenazine).

Twitching is more frequent in late REM sleep than in early REM sleep

The study used a piezo-electric limb sensor taped to the index finger of each participant to detect finger movement and calculate finger twitch density for each stage of sleep. The results suggest that finger twitching in REM sleep is distinguishable from finger twitching in most other sleep stages and increases as sleep progresses.

Furthermore, the study developed a simple algorithm to demonstrate that finger twitch density can be used to determine sleep states (wakefulness, REM sleep, or non-REM sleep), indicating that further investigation of this approach to REM sleep measurement is warranted.

Overall, the findings provide evidence that finger twitching can be used to detect REM sleep and that it becomes more frequent in late REM sleep compared to early REM sleep.

A finger-mounted device can be used to measure twitching

A study was conducted to assess the potential for a finger-mounted device to measure finger twitches and thereby differentiate between REM and non-REM sleep. The study involved 18 healthy adults aged 23.2 ± 3.3 years. A piezo-electric limb sensor was taped to the index finger of each participant to detect finger movement. The results showed that finger twitch density was greater in REM sleep than in non-REM sleep. The study concluded that a finger-mounted device could be used to measure finger twitches and differentiate between REM and non-REM sleep.

The advantages of using a finger-mounted device to measure twitching include its simplicity, low cost, and non-invasiveness compared to polysomnography. It also has the potential to be used in ambulatory settings, making it more convenient and accessible for patients.

However, there are some challenges to using finger-mounted devices for measuring sleep. One challenge is the inter-individual variability in twitch density, which means that a personalised algorithm would be needed to accurately detect sleep stages. Another challenge is the difficulty in discriminating between N1 (early light sleep) and REM sleep, as they have similar twitch densities.

Overall, a finger-mounted device has the potential to be a cost-effective and convenient way to measure twitching and differentiate between REM and non-REM sleep. However, further research and development are needed to improve the accuracy and practicality of this method.

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