Myoclonus refers to a quick jerking movement that you can't control. Hiccups are a form of myoclonus, as are the sudden jerks or "sleep starts" that you may feel just before falling asleep. These forms of myoclonus occur in healthy people and usually aren't serious.
Other forms of myoclonus may occur because of a nervous system disorder, such as epilepsy, a metabolic condition, or a reaction to a medicine.
Treating whatever condition causes myoclonus can help control symptoms. Sometimes the cause of myoclonus is unknown or can't be specifically treated. In these cases, the goal of treatment is to reduce the effects of myoclonus on quality of life.
People with myoclonus often describe their symptoms as jerks, shakes or spasms that are:
If your myoclonus symptoms become frequent and persistent, talk to your health care provider about a diagnosis and treatment options.
Myoclonus may be caused by a variety of underlying problems. It is commonly separated into different types based on what is causing it. The cause can help determine treatment.
This type of myoclonus occurs in healthy people and rarely needs treatment. Examples include:
Essential myoclonus occurs on its own, usually without other symptoms and without being related to any underlying illness. The cause of essential myoclonus is often unknown. In some cases, the cause is hereditary, meaning passed down in families.
This type of myoclonus occurs as part of an epileptic disorder.
Symptomatic myoclonus results from an underlying medical condition. It is sometimes called secondary myoclonus. Examples include:
Nervous system conditions that result in secondary myoclonus include:
To diagnose myoclonus, your health care provider reviews your medical history and symptoms and conducts a physical examination.
You may have tests to find the cause and rule out other potential causes of myoclonus. In some cases, imaging tests or nerve tests may be needed.
Electromyography (EMG). In this procedure, electrodes are placed on multiple muscles, especially muscles that are involved in the jerking.
An instrument records the electrical activity from the muscles when they are at rest and when they are contracted, such as when you bend your arm. These signals help determine the pattern and origin of the myoclonus.
Treatment of myoclonus works bets if you can stop the problem that's causing it. For example, treatment may focus on another condition, a medicine or a toxin that is causing the myoclonus.
Most of the time, however, the underlying cause can't be cured or eliminated. In these cases, treatment is aimed at reducing myoclonus symptoms, especially when they're disabling. There are no drugs specifically designed to treat myoclonus. But treatments for other diseases may help relieve myoclonus symptoms. More than one drug may be needed to control the symptoms.
Medicines that health care providers commonly prescribe for myoclonus include:
Anticonvulsants. Drugs used to control epileptic seizures may help reduce myoclonus symptoms. The most common anticonvulsants used for myoclonus are levetiracetam (Keppra, Elepsia XR, Spritam), valproic acid, zonisamide (Zonegran, Zonisade) and primidone (Mysoline). Piracetam is another anticonvulsant that's been found to be effective, but it's not available in the United States.
Valproic acid may cause side effects such as nausea. Levetiracetam may cause side effects such as fatigue and dizziness. Side effects from primidone may include sedation and nausea.
OnabotulinumtoxinA (Botox) injections may help treat various forms of myoclonus, particularly if only a single area is affected. This treatment blocks the release of a chemical messenger that triggers muscle contractions.
If myoclonus symptoms are caused by a tumor or lesion in the brain or spinal cord, surgery may be an option. People with myoclonus affecting parts of the face or ear also may benefit from surgery.
Deep brain stimulation has been tried in some people with myoclonus and other movement disorders. Electrodes are implanted within certain areas of the brain. The electrodes produce electrical signals to block the irregular impulses that can cause myoclonus. Researchers continue to study deep brain stimulation for myoclonus.
You'll probably first discuss your concerns with your primary care provider. Your provider might then refer you to a neurologist. A neurologist is a specialist trained in nervous system conditions.
Because appointments can be brief, and because there's often a lot to talk about, it's a good idea to arrive well prepared for your appointment. Here's some information to help you get ready for your appointment, and to know what to expect.
Your time with your health care provider is limited, so preparing a list of questions ahead of time will help you make the most of your time together. For myoclonus, some basic questions to ask include:
In addition to the questions that you've prepared, don't hesitate to ask questions during your appointment at any time that you don't understand something.
Your health care provider is likely to ask you a number of questions. Being ready to answer them may make time to go over any points you want to discuss in-depth. You might be asked:
