Sleep myoclonus is involuntary, nonrhythmic muscle twitching that occurs either as a person falls asleep or during sleep. The movements include hiccups, starts, and jerks.
Sleep myoclonus is not a disease but a symptom of several different conditions. Sleep myoclonus can also happen without a known cause.
This article discusses what sleep myoclonus is, its causes, and how doctors treat it.
According to the
The symptoms of sleep myoclonus occur when a person falls asleep or during sleep. It causes unpredictable and involuntary muscle jerks or spasms that may affect a single muscle or multiple muscle groups.
These movements may include:
- sudden jerking of the arms, legs, or torso
- shock-like muscle twitches that last for a brief period
- localized or widespread muscle spasms
- muscle spasms that occur in response to external stimuli
There are two types of myoclonus:
- Physiologic myoclonus: These involve quick muscle twitches followed by relaxation. One example is when a person experiences “sleep starts” as they drift to sleep.
- Pathologic myoclonus: This involves contractions that begin in one part of the body and spread to other muscles in other areas.
People with sleep myoclonus may have difficulty falling asleep or experience poor sleep quality.
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Physiologic forms of myoclonus, such as hiccups or sleep starts, can occur in healthy people without leading to serious complications. However, frequent or widespread myoclonus may indicate an underlying neurological disorder.
The exact cause of myoclonus remains unknown. However, in most cases, myoclonus is associated with problems affecting the
Sleep myoclonus can occur by itself or alongside other symptoms of nervous system disorders.
The possible causes of sleep myoclonus vary depending on a person’s age.
Infants and children
Causes of sleep myoclonus in children may include:
- Sleep disorders: Although sleep myoclonus can occur on its own, it can also occur as a symptom of a sleep disorder.
- Pediatric periodic limb movement disorder (PLMD): PLMD is a sleep movement condition that affects children. PLMD causes brief muscle spasms in the legs or arms during sleep.
- Rhythmic movement disorder: Children with
rhythmic movement disorder (RMD) may exhibit rocking or head-jerking movements while falling asleep or transitioning to deep sleep. RMD often occurs alongside developmental disorders, such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorders, and Tourette’s syndrome. - Epilepsy: According to the
NINDS , myoclonus frequently occurs in people with epilepsy. Juvenile myoclonic epilepsy (JME) is a form of epilepsy that involves myoclonic seizures. It accounts for5 to 10% of all cases of epilepsy. The onset of JME symptoms usually occurs in children between 12 and 18 years old.
In adults
Causes of sleep myoclonus that mainly affect adults include:
Restless leg syndrome
Restless leg syndrome (RLS), or Willis-Ekbom disease, is a disorder that affects sleep.
It causes an uncontrollable urge to move the legs, usually because of an uncomfortable sensation, which moving temporarily eases.
It typically happens in the evening or nighttime when a person is sitting or lying down awake.
The nature of its symptoms suggests that RLS is a neurological condition. However, the cause of RLS remains unknown.
Research from the
Multiple sclerosis (MS)
According to the National MS Society, focal and segmental myoclonus are common movement disorders associated with MS.
It is unclear whether MS can directly cause sleep myoclonus. However, the condition has links with numerous sleep disorders, including nocturnal leg spasms and RLS.
Huntington’s disease
People with Huntington’s disease may experience involuntary muscle jerks, known as chorea, as well as changes in cognition and sleep.
As the disease progresses, involuntary muscle movements may start affecting a person’s sleep. According to a
In older adults
Older adults may develop sleep myoclonus due to:
Alzheimer’s disease
Those with Alzheimer’s disease
A doctor can prescribe medications to help reduce this symptom.
Parkinson’s disease
Parkinson’s disease is a neurodegenerative disorder that typically affects people around the
- tremor, or uncontrollable shaking
- muscle rigidity or stiffness
- bradykinesia, which refers to the slowing of automatic muscle movements
- loss of coordination
- changes in posture
People who have Parkinson’s disease may also have urinary and bowel problems, cognitive changes, and difficulty sleeping.
Creutzfeldt-Jakob disease (CJD)
CJD is a progressive brain disorder that leads to cognitive and behavioral changes, as well as involuntary muscle jerks and loss of coordination.
Symptoms of CJD typically first appear in adults ages
Treating any underlying condition that contributes to myoclonus will help alleviate unwanted muscle spasms. If the cause is unknown, a doctor will treat the symptoms as they appear.
Examples of medication that can help treat sleep myoclonus
- antiseizure and anticonvulsant medications, such as clonazepam (Klonopin), phenytoin (Dilantin), and levetiracetam (Keppra)
- sedatives, such as barbiturates
- 5-hydroxytryptophan, an amino acid in serotonin
- botulinum toxin (Botox)
Home remedies
The research on alternative therapies for myoclonus is limited. However, stretching and massaging problematic areas of muscle may help prevent mild muscle spasms or reduce the severity of moderate-to-severe spasms.
People should speak with a doctor if they experience frequent myoclonic episodes that affect their ability to fall or stay asleep.
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.
Medications and at-home remedies may help relieve myoclonic spasms at night. However, all treatments come with possible side effects. People should consult a doctor before starting any new medication or supplement.
The following are commonly asked questions about twitching during sleep.
Is sleep myoclonus serious?
Twitching during sleep does not necessarily indicate an underlying health condition. Physiologic forms of myoclonus, such as a sleep start (hypnic jerk), can happen to anyone and do not cause serious complications.
As widespread or persistent twitching can indicate an underlying health condition, a person may wish to contact a doctor in these cases.
Is twitching normal in REM sleep?
Twitching is common during REM sleep. For example, a
Sleep myoclonus is defined as involuntary and nonrhythmic muscle twitching that occurs as a person is falling asleep or when they are already sleeping. Examples include hiccups and hypnic jerks.
Myoclonus can be physiologic or pathologic. Physiologic myoclonus is common and occurs in healthy individuals. Pathologic myoclonus can indicate an underlying health condition.
Sleep myoclonus is not a condition itself, but a clinical sign. A person should contact a doctor if they experience widespread or persistent sleep myoclonus.