Flinching In Sleep: Why It Happens And How To Stop It

Involuntary muscle twitching or flinching while falling asleep or during sleep is known as a hypnic jerk or sleep start. These sudden muscle contractions can occur on one side of the body or the entire body and may be accompanied by vocalizations or sharp cries. While hypnic jerks are generally harmless, they can sometimes be indicative of other sleep-related issues or underlying medical conditions. Factors such as excessive caffeine consumption, vigorous exercise before sleep, emotional stress, and sleep deprivation can increase the likelihood of experiencing hypnic jerks. Understanding and addressing these factors can help improve sleep quality and reduce instances of hypnic jerks.

Hypnic jerks, or sleep starts, are sudden involuntary muscle contractions

The exact cause of hypnic jerks is unknown, but researchers have several theories. One theory suggests that it is caused by a misfire between nerves in the reticular brainstem, which creates a reaction that leads to the jerk. Another theory proposes that the brain misunderstands the relaxation of muscles as the body prepares for sleep. The brain then thinks the person is falling and causes the muscles to tense to "catch" the body, resulting in a jerk.

Certain risk factors can increase the likelihood of experiencing hypnic jerks, such as excessive caffeine and stimulant consumption, vigorous exercise before sleep, emotional stress, and sleep deprivation. Managing these factors through lifestyle changes, such as reducing caffeine intake, avoiding stimulants, and improving sleep habits, can help reduce the frequency of hypnic jerks.

While hypnic jerks themselves are not a cause for concern, they can sometimes be indicative of other sleep-related issues or underlying medical conditions. For example, frequent or widespread myoclonus may suggest an underlying neurological disorder. Additionally, hypnic jerks can lead to anxiety about falling asleep and insomnia, especially if they are intense or accompanied by upsetting hallucinations or dreams of falling.

If you are experiencing frequent hypnic jerks that are disrupting your sleep or causing distress, it may be helpful to consult a doctor or a sleep specialist. They can provide guidance and recommend appropriate treatments or lifestyle changes to improve your sleep quality.

Nightmares or night terrors can cause people to move or cry out in their sleep

Nightmares and night terrors are common causes of sleep disturbances. Night terrors are partial awakenings that induce panic or fear. They occur when the brain is partially asleep and partially awake, causing a state of panic or fear. During a night terror, you may cry out, scream, or move around violently. Many people with night terrors go back to sleep as soon as the episode ends, and they often have no memory of the night terror the next morning.

Night terrors are a type of parasomnia, a group of sleep disorders that affect sleep movements and behaviour. They typically occur during the non-rapid eye movement (NREM) stage of sleep, usually in the first part of the night. While night terrors are more common in children, they can also occur in adults, especially those with underlying sleep disorders such as sleep apnea or periodic limb movement disorder.

Nightmares, on the other hand, are typically associated with rapid eye movement (REM) sleep, which occurs later in the night. During REM sleep, our brains are more active, and we are more likely to dream. Nightmares can cause us to wake up suddenly, crying or screaming, and we often have vivid memories of the frightening dream upon awakening.

Both nightmares and night terrors can lead to violent movements during sleep. These can include flailing arms and legs, jumping out of bed, or even sleepwalking. In some cases, people with night terrors or nightmares may injure themselves or others during these episodes.

If you are experiencing frequent nightmares or night terrors that are affecting your sleep quality or causing distress, it is important to seek help. A healthcare provider can evaluate your symptoms and provide guidance or treatment to help manage these sleep disturbances.

Sleep disorders such as restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) can cause jerking movements

Restless legs syndrome (RLS) is a condition that involves an irresistible urge to move the legs, and sometimes the arms, when a person is sitting still or lying down. It is often associated with strange and intense sensations in the legs or arms, which can be described as burning, creeping, or tugging sensations, or like insects crawling inside the legs. RLS can make it difficult for people to relax and fall asleep, leading to poor sleep quality and daytime sleepiness.

Periodic limb movement disorder (PLMD), on the other hand, involves repetitive and rhythmic movements of the arms, legs, or both during sleep. These movements occur every 20 to 40 seconds and can include brief muscle spasms, twitches, or jerks. People with PLMD are usually not aware of their movements or the brief awakenings that may follow. However, they may experience insomnia, excessive daytime sleepiness, and poor sleep quality.

Both RLS and PLMD are often linked, with a high percentage of people with RLS also experiencing PLMD. Treatment for these disorders involves medication that helps reduce the movements or aids in sleeping through them. While there is no cure for these disorders, medications such as gabapentin enacarbil, a seizure medication, and dopaminergic agents have been found to be effective in relieving symptoms.

In addition to RLS and PLMD, there are other potential causes of jerking movements during sleep. One common phenomenon is sleep myoclonus, which refers to involuntary muscle twitches and jerks that can occur as a person falls asleep or during sleep. Sleep myoclonus can be physiologic, occurring in healthy people without underlying complications, or pathologic, indicating an underlying neurological disorder. Hypnic jerks are another common cause of involuntary muscle twitches that can occur as a person falls asleep, often due to high levels of stress and anxiety, or as a result of consuming stimulating substances such as caffeine, nicotine, or alcohol.

High levels of stress and anxiety can make it difficult to relax and fall asleep, potentially triggering a hypnic jerk

Stress and anxiety can contribute to insomnia and sleep deprivation, increasing the likelihood of hypnic jerks. When stressed or anxious, elevated cortisol levels and anxious thoughts can interfere with restful sleep, making it challenging to transition between wakefulness and sleep. This disrupted transition can lead to involuntary muscle twitches associated with hypnic jerks.

Additionally, stress and anxiety can heighten alertness, making it easier for individuals to startle and wake up when hypnic jerks occur. Research using electroencephalography (EEG) has identified specific brain activity during hypnic jerks, known as vertex sharp waves, which may contribute to the sudden muscle contractions.

To mitigate the impact of stress and anxiety on sleep and potentially reduce the occurrence of hypnic jerks, individuals can consider incorporating relaxation techniques into their bedtime routine. This may include guided meditations, breathing exercises, gentle stretches, listening to music, or reading a book. Reducing caffeine and stimulant intake, particularly close to bedtime, can also help improve sleep quality and potentially lessen the frequency of hypnic jerks.

While hypnic jerks are typically benign, if they cause distress or are accompanied by other symptoms, individuals are advised to consult a healthcare professional. In some cases, addressing underlying stress and anxiety through lifestyle changes or medical intervention can help reduce the intensity and frequency of hypnic jerks.

REM sleep behaviour disorder (RBD) involves acting out dreams, which can include flinching or twitching

During normal REM sleep, the body experiences temporary muscle paralysis, known as atonia, while the brain shows activity similar to wakefulness. This allows us to dream safely, lying still while the brain is active. However, for individuals with REM sleep behaviour disorder (RBD), this normal muscle paralysis does not occur, enabling them to physically act out their dreams.

RBD is a sleep disorder, specifically a parasomnia, and is not a mental health condition. People with RBD are not aware of their behaviours during sleep and may only find out about their condition when their bed partner informs them or when they wake up with an injury. The symptoms of RBD can vary in severity, ranging from mild muscle twitches or limb movements to more violent actions such as kicking, punching, or grabbing the air or their bed partner. About eight in ten people with RBD experience sleep-related injuries, and the disorder can coexist with other neurological conditions.

The exact cause of RBD is unknown, but researchers believe it may be related to certain neural pathways in the brain. One theory suggests that an issue in the brainstem, specifically the pons, leads to REM sleep without atonia. The pons controls muscle paralysis during REM sleep, and lesions in this area have been associated with Parkinson's disease, Lewy body dementia, and multiple system atrophy.

If you suspect you may have RBD, it is important to consult a healthcare provider. They may recommend a sleep study, which typically involves monitoring your breathing, eye movements, arm and leg movements, brain and heart activity, and blood oxygen levels. Treatment options can help reduce symptoms and prevent injuries, and it is crucial to create a safe sleeping environment.

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