Myoclonic seizures involve sudden muscle contractions that cause twitching. Myoclonus is the medical term for quick, sudden muscle movements.

A seizure is caused by an abnormal change in the brain’s electrical activity. If you have repeated seizures, it’s called epilepsy.

It’s estimated that 3.4 million people in the United States have active epilepsy. But you can have seizures even if you don’t have epilepsy.

There are many possible causes and kinds of seizures. A myoclonic seizure is a type of generalized seizure, meaning it occurs on both sides of the brain. It causes muscle jerking that often lasts for 1 or 2 seconds.

To learn more about myoclonic seizures, read on. We’ll cover the symptoms, causes, and treatment, along with the different types of myoclonic epilepsies.

A myoclonic seizure happens when your muscles suddenly contract, causing quick twitching movements. It usually affects one side of the body and involves the neck, shoulders, and upper arms. It can also affect the whole body.

A myoclonic seizure can be so short that it’s mistaken for:

  • clumsiness
  • tics
  • nervousness

Sometimes, several myoclonic seizures can happen within a short time.

Common symptoms of myoclonic seizures include:

  • quick jerking, often after waking up
  • rhythmic movements
  • sensation of an electric shock
  • unusual clumsiness

Sometimes myoclonic seizures can cluster together, leading to several short jerks in a row.

What are myoclonic atonic seizures?

An atonic seizure causes a sudden loss of muscle tone. This can lead to a fall, also called a drop attack.

If this happens with a myoclonic seizure, it’s called a myoclonic atonic seizure. It causes muscle jerking, followed by muscle limpness.

What is myoclonic astatic epilepsy?

Myoclonic astatic epilepsy, or Doose syndrome, is characterized by repeated myoclonic-atonic seizures. It can also cause absence or generalized tonic-clonic (GTC) seizures.

This condition appears in childhood. It’s quite rare, affecting 1 or 2 out of 100 children with epilepsy.

Myoclonic seizures vs. tonic-clonic seizures

During a myoclonic seizure, some or all of your muscles might twitch. You’ll also likely stay conscious.

This is different than a tonic-clonic seizure, previously called a “grand mal” seizure, which includes two phases.

During the tonic stage, you lose awareness, and your whole body becomes stiff. The seizure progresses to the clonic stage, where your body jerks and shakes.

Tonic-clonic seizures may last several minutes or longer. You won’t remember what happened during the seizure.

Possible causes of myoclonic seizures include:

In many cases, the cause of myoclonic seizures is unknown.

Some factors can increase the risk of myoclonic seizures. These include:

  • family history of epilepsy
  • personal history of seizures
  • young age
  • being female (for juvenile myoclonic epilepsy)
  • stroke
  • activities that may cause brain injury
  • being born with brain abnormalities

Juvenile myoclonic seizures are myoclonic seizures that start in adolescence. Generally, they appear between ages 12 and 18, but they can start anywhere between 5 to 34.

If the seizures repeat, it’s called juvenile myoclonic epilepsy (JME). JME can also cause GTC seizures and absence seizures along with myoclonic seizures. JME affects 5 to 10 percent of people with epilepsy.

The condition may be inherited. In other cases, the cause is unknown.

Myoclonic epilepsy disorders cause myoclonic seizures, along with other symptoms. These include:

Progressive myoclonic epilepsy

Progressive myoclonic epilepsy (PME) is a group of rare conditions, rather than a single disorder. They cause myoclonic seizures and other seizure types, often GTC seizures.

Examples of PME disorders include:

  • Lundborg disease
  • Lafora disease
  • sialidosis
  • neuronal ceroid lipofuscinoses

PMEs can appear at any age, but they often start in late childhood or adolescence. They’re called “progressive” because they get worse over time.

Lennox-Gastaut syndrome

Lennox-Gastaut syndrome often appears between ages 2 and 6. It causes myoclonic seizures and other seizures, which may include:

This syndrome is rare. It often affects children with brain damage due to trauma or brain development issues and other neurological disorders.

If you think you’re having a myoclonic seizure, stop what you’re doing. Avoid moving around during the seizure.

If someone else is having a myoclonic seizure, make sure they don’t get hurt. Clear the area and stay with them until the seizure is done.

Remember, myoclonic seizures are brief. They often last for a few seconds. Focus on staying safe and reducing the risk of injury.

If you’ve already been diagnosed with epilepsy, continue visiting your doctor. This will help them monitor your progress and adjust your treatment as necessary.

See your doctor if you think you’re experiencing myoclonic seizures. Also, seek medical help if you have:

  • muscle jerking or twitching
  • unusual clumsiness
  • a seizure for the first time
  • a long seizure
  • an injury during a seizure
Medical emergency

Call 911 or go to the nearest emergency room if someone:

  • has a first-time seizure
  • has a seizure that lasts for more than 5 minutes
  • has multiple seizures in a short time
  • becomes unconscious during a seizure
  • has trouble breathing or waking up after the seizure
  • is pregnant and having a seizure
  • has a chronic condition, like heart disease, along with a seizure
  • gets hurt during the seizure

Treatment for myoclonic seizure is similar to treatment for other seizures. Your exact treatment will depend on several factors, including:

  • your age
  • how often you have seizures
  • the severity of your seizures
  • your overall health

Options include:

Anti-epilepsy drugs

Anti-epilepsy drugs (AED) are used to prevent seizures. Some seizure drugs used for myoclonic seizures include:

  • valproic acid
  • levetiracetam
  • zonisamide
  • benzodiazepines

AEDs may cause side effects. You may need to try several drugs and doses to determine the best option.

Lifestyle changes

Some lifestyle changes may help prevent your seizure triggers. Examples include:

  • getting enough sleep
  • avoiding flickering lights
  • practicing stress management
  • avoiding or limiting alcohol
  • eating meals at regular intervals


If AEDs don’t control your seizures, you may need surgery, but this is only done in very rare circumstances. This involves removing a part of your brain where the seizures happen.

You might also have surgery if the part where your seizures are happening can be removed without major risks.

JME treatment involves anti-epilepsy drugs. Typically, valproic acid is the most effective option. It can treat all types of seizures that occur with JME.

Other medications used for JME include:

  • levetiracetam
  • lamotrigine
  • topiramate
  • zonisamide

Anti-epilepsy drugs may be used alone or in combination with vagal nerve stimulation.

To determine whether you have myoclonic seizures, your doctor will evaluate the following:

  • Medical history. They’ll ask questions about your symptoms and what you were doing when the seizure started.
  • Family history. Since epilepsy may be genetic, your doctor will want to know about your family history.
  • Electroencephalogram. An electroencephalogram (EEG) tracks the brain’s electrical activity.
  • Imaging tests. Imaging tests, like an MRI or CT scan, create images of your brain. They can show tumors or structural issues, which may help your doctor diagnose your symptoms.
  • Blood tests. Your doctor might order blood tests to rule out other possible conditions. They may check for markers like abnormal electrolyte levels or signs of infection.
  • Spinal tap. A spinal tap might be used to check for infections.

The outlook for myoclonic epilepsy varies.

In most cases, anti-epilepsy drugs can provide long-term management. You might need to take the medication for the rest of your life. But if your seizures go away, you may be able to stop taking medication.

Here’s the outlook for specific epilepsies:

  • Juvenile myoclonic epilepsy. About 60 percent of people with JME achieve long-term seizure absence with anti-epileptic medications. Approximately 15 to 30 percent of people with JME can stop taking medication without experiencing additional seizures.
  • Myoclonic astatic epilepsy. In about 50 percent of children with myoclonic astatic epilepsy, AEDs can manage seizures. However, they’ll likely develop learning difficulties which can be mild to severe depending on how hard the epilepsy is to manage.
  • Progressive myoclonic epilepsies. Depending on the specific condition, PMEs may cause disability over time. In other cases, people with PMEs may be able to live independent lifestyles.

A myoclonic seizure causes muscle jerking, typically after waking up. It usually lasts for a few seconds, so it often goes unnoticed.

Myoclonic epilepsy may be inherited. But often, the specific cause is unknown.

If you think you have myoclonic seizures, or if you have a first-time seizure, see a doctor. They can recommend a treatment plan based on your symptoms.