Sleep myoclonus causes involuntary muscle twitches during sleep or when a person falls asleep. In some cases, sleep myoclonus occurs on its own without an identifiable cause. Sleep myoclonus can also develop as a result of a sleep disorder or a neurological disorder.
Hypnic jerks and other types of myoclonus start in the same part of your brain that controls your startle response. When you fall asleep, it is suspected that a misfire sometimes occurs between nerves in the reticular brainstem, creating a reaction that leads to a hypnic jerk.
Hypnic jerks are generally considered a normal part of falling asleep and do not typically require treatment. However, you may want to talk to your doctor if sleep starts are disrupting your sleep or causing anxiety.
“Hypnic jerks are almost always normal or benign; that is, they are not a sign of an underlying disease process. However, hypnic jerks can occur so frequently that they disrupt sleep in some individuals, and on rare occasions, they may be associated with an underlying neurological disorder.”
In summary
Random hypnic jerks and twitches in sleep are completely normal and quite common. They usually don't indicate an underlying health issue and are simply muscle contraction during sleep that ranges from mild to intense.
Myoclonus may occur normally (for example, jerking of a leg when a person is falling asleep), but it may result from a disorder, such as liver failure, a head injury, low blood sugar, or Parkinson disease or from use of certain drugs. Muscles may jerk quickly or slowly, and jerking may be rhythmic or not.
Caffeine, amphetamines, antidepressants, antipsychotics, benzodiazepines, and stimulants can all increase the likelihood of experiencing hypnic jerks.
Physiologic myoclonus involves quick muscle twitches followed by relaxation. Examples are hiccups and the jerks or “sleep starts” that some people experience while drifting off to sleep. This form occurs in healthy people, causes no difficulties, and does not require medical treatment.
The same phenomenon is called a hypnic jerk if it occurs upon awakening. For example, you might believe that you were falling. A leg movement may incite a fragmentary dream image that you were perhaps kicking a soccer ball.
Nocturnal seizures happen while a person is falling asleep or waking up. They can cause unusual nighttime behavior, such as waking for no reason, urinating while sleeping, and jerking and shaking of the body. They are linked to epilepsy. Nocturnal seizures are usually a type of seizure called a tonic-clonic seizure.
Myoclonic seizures are characterized by brief, jerking spasms of a muscle or muscle group. They often occur with atonic seizures, which cause sudden muscle limpness.
Hypnic jerks generally occur during the stage of sleep in which your muscles start to relax and you begin drifting off. During this time, motor areas of the brain can become spontaneously stimulated. Your brain may misinterpret this stimulation as wakefulness during a less-than-seamless transition to sleep.
Are there any other signs or symptoms of hypnic jerks? Apart from the obvious muscle twitches, you may also experience increased heartbeat, rapid breathing, sweating, clammy skin, and a falling sensation.
Generally, antiepileptic drugs such as valproate, levetiracetam and piracetam are effective in cortical myoclonus, but less effective in other forms of myoclonus. Clonazepam may be helpful with all types of myoclonus.
Anxiety can come with a range of physical symptoms, including muscle twitches. Muscle twitches are caused when your brain interprets anxiety as stress and sends signals to your body that trigger muscle spasms. These spasms can occur in different muscle groups at any time.
Benzodiazepines are the primary symptomatic treatment at end-of-life. While any benzodiazepine will work, clonazepam and lorazepam are commonly used. A continuous infusion of midazolam has also been suggested given the drug's compatibility with morphine and short half-life, allowing rapid dose titration.
Huntington's Disease
Symptoms include jerking; uncontrollable movements of the limbs, trunk, and face; progressive loss of mental abilities; and the development of psychiatric problems. The condition is hereditary – a child with one affected parent has a 50 percent chance of developing Huntington's disease.
Symptoms. Nocturnal seizures may range from awakening for no clear reason, sometimes multiple times a night, to shouting, screaming and violent movements of the arms and legs. Patients may also thrash around or act confused.
Signs you had a seizure in your sleep
Falling out of bed. Waking up with bruises that were not there before. Feeling confused or having a headache the next morning. Wetting the bed.
Episodes of neck myoclonus occur typically during REM sleep; during NREM sleep they are detected very rarely.
Seizures in adults with no seizure history can be caused by a number of factors ranging from high blood pressure, drug abuse and toxic exposures to brain injury, brain infection (encephalitis) and heart disease.
Video Electroencephalography
Using video EEG, your doctor can confirm whether you are having an epileptic seizure and, if so, its type and location in the brain. Video EEG recordings can be used whether you are in the hospital or at home.
Can sleep deprivation trigger a seizure? Yes, it can. Seizures are very sensitive to sleep patterns. Some people have their first and only seizures after an "all-nighter" at college or after not sleeping well for long periods.