Myoclonus

Myoclonus is an uncontrollable muscle movement that’s sudden and brief. This can happen for a wide range of reasons. Many causes are normal and harmless, but myoclonus can also be a symptom of serious nervous system conditions. Depending on how and why it happens, this symptom may be treatable, and some conditions that cause it may be preventable. Overview What is myoclonus? Myoclonus is a brief, sudden muscle movement (like a twitch, jerk or spasm). It happens when muscles incorrectly activate and usually lasts just a fraction of a second. It can affect a single muscle or a group of them. Some causes are more likely to affect muscles in your hands or feet, shoulders or hips, back or face. Myoclonus (pronounced “my-OCK-lon-us”) can happen in people who are healthy at some point in their life. However, it’s also a possible symptom of several medical conditions, some of which are serious. There are two main ways myoclonus happens: • Positive myoclonus: This is when muscles contract or flex suddenly. • Negative myoclonus: This is when muscles relax suddenly (the technical term for this is “ Possible Causes What are the most common causes of myoclonus? Myoclonus can happen for many reasons. Some of those reasons are normal and expected. Others happen because of specific conditions and disorders that affect various systems in your body. Experts divide myoclonus into four main categories. Normal forms of myoclonus Several processes in your body can cause myoclonus to happen for ...

• Electroencephalography (EEG). This procedure records the electrical activity of the brain. It may help determine where in the brain the myoclonus originates. First, small electrodes are attached to the scalp. You then may be asked to breathe deeply and steadily and look at bright lights or listen to sounds. These actions may uncover irregular electrical activity. • 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. • Evoked potential studies. These tests measure the electrical activity of the brain, brainstem and spinal cord that is triggered by touch, sound, sight and other stimuli. • Magnetic resonance imaging (MRI). An MRI scan may be used to check for structural problems or tumors inside the brain or spinal cord, which may cause the myoclonus symptoms. An MRI scan uses a magnetic field and radio waves to produce detailed images of the brain, spinal cord and other areas of the body. • Laboratory tests. Your health care provider may suggest genetic testing to help identify possible causes of myoclonus. Blood or urine tests may be needed to check for metabolic disorders, autoimmune disease, diabetes, and kidney or liver disease. They also can check for drugs or toxins. T...

Myoclonus is a sudden muscle jerk. It can happen alone or stem from a medical condition. Possible causes include medication side effects, damage to the nervous system, and disorders that affect the brain. In some people with myoclonus, the jerks are mild and have little or no effect on daily life. In these cases, treatment might not be necessary. More severe myoclonus can limit mobility and cause pain or discomfort. When the muscle jerks are a symptom of epilepsy, the treatment usually involves anti-seizure medication. For other causes, doctors may recommend This article discusses the types of myoclonus, its causes, and the treatment options. Share on Pinterest AsiaVision/Getty Images Myoclonus is the medical term for a sudden jerking of a muscle or group of muscles. The jerking is involuntary, meaning that the person is not in control of the movement. Muscle jerks can happen at random or in response to a trigger, and they may repeat in a pattern. Myoclonus is not always serious — for example, it can present as However, it can sometimes be a symptom of an underlying health condition, such as The exact causes are still unclear. However, damage to or dysfunction in parts of the brain that control movement can result in muscle jerks. There are many forms of myoclonus, and a doctor may describe the condition as primary or secondary. Primary myoclonus appears on its own with no other symptoms. It can develop in various parts of the body, including the legs and the roof of the m...

What Is Myoclonus? Myoclonus is sudden muscle spasms that you can’t control. They can be normal -- a hiccup or a "sleep start" when you’re falling asleep, for example -- or they may be a sign of a serious health condition such as Myoclonus might include sudden jerking, quivering, or Types of Myoclonus The types of myoclonus include: • Action. It’s triggered by movement. It can affect your arms, legs, face, and voice. • Physiological. This type happens in people with no underlying health problems. It causes hiccups, twitches when you’re startled, and spasms when you’re just falling asleep or waking up. • Essential. The twitches or jerks are the only sign. It may become more severe over time. Sometimes, it runs in families. • Symptomatic (secondary). This is caused by another health condition, such as an infection, a stroke, a brain tumor, a lack of oxygen, or contact with a chemical or drug. • Stimulus-sensitive. This is triggered by things in the world around you like lights, noise, or movement. • Brainstem. A sudden noise or something you see might cause a grimace. Your elbows, knees, neck, and other parts of your body may flex. • Cortical reflex. Doctors think this is a kind of epilepsy. People who have it are prone to sudden jerk-like movements in their upper limbs and face. • Palatal. This is a tremor in the roof or soft palate of your • Reticular reflex. Twitching or jerking throughout your whole body can happen with this kind of myoclonus. Triggers include movements ...

Myoclonus is a sudden and involuntary muscle spasm. It is usually a symptom of an underlying disorder and can interfere with eating, talking, and walking. The movement is involuntary and can’t be stopped or controlled. It may involve one muscle or a group of muscles. The movements may occur in a pattern or randomly. Hiccups are a mild type of myoclonus, a muscle twitch followed by relaxation. These types of myoclonus are rarely harmful. However, some forms of myoclonus can cause more serious, recurring, shock-like spasms. Myoclonus may develop on its own or as a result of: • infection • • • • • • lipid storage disease • adverse effects of drugs or chemicals • • • Myoclonus also is a symptom of numerous neurological disorders such as: • • • • • • • • paraneoplastic syndromes (conditions that affect some cancer patients) • corticobasal degeneration • • There are many types of myoclonus. The condition is typically described according to the underlying causes or where the symptoms originate. The following are some of the most common types: • Action myoclonus is the most severe form. It may affect the arms, legs, face, and voice. The muscular jerking is made worse by attempts at controlled, voluntary movement. It’s often caused by a lack of oxygen or blood flow to the brain. • Cortical reflex myoclonus originates in the outer layer of the brain tissue. It’s thought to be a form of epilepsy. Spasms may affect a few muscles in one part of the body or many muscles all over. It can...