Pediatric Myoclonus

Pediatric myoclonus is a quick, involuntary, muscle jerk that starts and stops very quickly. The movement can be repetitive, but usually occurs in different places on the body in the same person.

What is Pediatric Myoclonus?

Myoclonic twitches happen unexpectedly and will range from small disturbances (such as hiccups) to severe, jarring movements that affect a child’s quality of life (including problems eating, talking or walking).

Myoclonic movements can’t be controlled and can occur at any time — often happening at night when the body begins to relax at the beginning of sleep. The actions can move from one location of the body to another and may vary in frequency — from multiple twitches a minute to a few spasms per hour.

What are the different types of Pediatric Myoclonus?

There are seven classifications of myoclonus:  

Action myoclonus

Twitches that are caused or intensified by voluntary movements, such as writing or walking. This type can affect the arms, face, legs or voice.

Cortical reflex myoclonus

A type of myoclonus that takes place in the information processing part of the brain. It can be a type of epilepsy, but also occurs outside of epilepsy. It can affect a few muscles in one part of the body or impact multiple muscles in numerous locations. This can be caused by a change in stimulation, such as a loud noise, a change in the lighting or being startled. 

Essential myoclonus

This type can impact multiple family members (inherited) or occur without family history. This form may also present with dystonia.

Palatal myoclonus

Causes contractions near one or both sides of the roof of the mouth (soft palate). It can also affect the face, tongue, throat or diaphragm. The twitches can make a clicking noise, occur rapidly (as often as 150 per minute) and can take place during sleep.

Progressive myoclonus epilepsy (PME)

A rare disorder that begins in childhood and becomes worse over time. It includes seizures and problems walking or talking.

Reticular reflex myoclonus

This is a type of myoclonus that begins in the brain stem, specifically in the location that controls breathing and heartbeat. Typically, the muscle spasms affect the entire body, but for some people, it will only disturb one specific body part at a time, like the legs. The twitches can be caused by voluntary movements or an outside trigger, such as a loud noise.

Stimulus-sensitive myoclonus

These muscle spasms are caused by outside triggers like a surprise or loud noise.

What are the signs and symptoms of Pediatric Myoclonus?

Symptoms of myoclonus include quick, involuntary muscle spasms. The frequency, intensity, and location of the twitches depend on the type of myoclonus. 

How is Pediatric Myoclonus diagnosed?

Diagnostic tests your doctor may order include:

  • Blood tests
  • Electroencephalogram (EEG) (detects electrical activity in the brain)
  • Genetic testing
  • Magnetic resonance imaging (MRI) (imaging test that produces a detailed, 3-D image of the body using a magnetic field)

What are the causes of Pediatric Myoclonus?

Myoclonus can occur at any age and be due to several possible triggers, which include:

How is Pediatric Myoclonus treated?

Doctors may prescribe medications to treat pediatric myoclonus. If they are not effective, deep brain stimulation may be an option. With DBS therapy, surgeons implant a small device under the skin in the chest called a neurostimulator. It sends impulses to electrodes placed in the parts of the brain responsible for involuntary movements to help control them.

Pediatric Myoclonus Doctors and Providers