Myoclonus refers to sudden involuntary twitching of a muscle or a group of muscles. It can be as a result of muscle contractions or muscle relaxation. Myoclonus due to muscle contraction is referred to as positive myoclonus whereas myoclonus due to muscle relaxation is referred to as negative myoclonus. Anyone can experience this condition, and it is not necessarily an illness but more of a symptom. In most cases, it is a temporary nerve dysfunction which is harmless. However, in rare cases it can be an indication of an underlying medical problem such as epilepsy, head injury, side effect to medication, Parkinson disease, or a metabolic condition.2
Who Is At Risk For Myoclonus?
Males and females have an equal risk of experiencing myoclonus as well as children. In infants, muscle twitching often occurs either after feeding or during sleep. Since it is not a form of ailment, it can occur in normal healthy people. For example; hiccups and leg twitching when falling asleep; in infants, muscle twitching often occurs either after feeding or during sleep; these myoclonus are normal and can occur in any individual or baby out there. People with myoclonus describe the phenomena as a shock-like, incontrollable, sudden, and brief muscle jerking that often occurs in a localized part of the body. The intensity of the muscle movement varies and it can either be a burst of spontaneous muscle activity or muscle silencing.1
Generally speaking, there are about 1.3 cases of myoclonus in 100,000 persons and in case of persistence or serious conditions; there are about 8.6 cases of myoclonus per 100,000 people. As much as anyone can experience this symptom, the numbers of affected individuals varies depending on the form they have. While normal myoclonus i.e. hiccups and leg twitching when asleep can occur in a large number of healthy individuals, epileptic myoclonus only affects those who have epilepsy, which is essentially a small population. Secondary myoclonus on the other hand is also a bit more common especially in people who react to certain medication, have had a head injury or experiencing a neurological condition such as a stroke, dementia or Alzheimer’s disease.1
Severe cases of myoclonus, in particular progressive myoclonus, occur in people who have had serious brain or nerve injury. In such a case, the person experiences difficulties in movement, speaking, waking and even eating. Like the name suggests, people with progressive myoclonus keep getting worse over time. Other risk factors that increase the likelihood of myoclonus are genetic disorders, brain tumors, kidney or liver failure, and chemical poisoning. Individuals who have also stayed for a long period without oxygen (prolonged hypoxia) can also experience this symptom.
Normal myoclonus doesn’t pose a life-threatening situation to an individual, thus no need for treatment. But, for people who experience persistent myoclonus, diagnosis of the underlying condition and treatment is necessary. The most appropriate treatment therapy is that which concentrates on identifying the origin of myoclonus and tackling the underlying condition. In case of myoclonus due to epileptic disorder, antiepileptic medication or medication with anti-seizure effect can be administered. If the underlying condition is indeterminable, then treatment should be offered to control myoclonus as a symptom. To effectively manage myoclonus, treatment with multiple drugs is advised since some drugs may not have a greater effect on their own.
Conditions Similar To Myoclonus
There are several conditions which are similar to myoclonus. Therefore, if you have symptoms such as muscle twitching in several muscles around the body that are involuntary and shock-like, you should visit a doctor for further investigation. Some of the conditions that can be mistaken for myoclonus include Tourette syndrome, torsion dystonia, benign essential tremor and Huntington’s disease.1
Myoclonus can either be a normal harmless jerking of a muscle or group of muscles. On the other hand, it can also signify a serious underlying condition. So, if you have a bothering twitching of muscle(s) that occurs frequently, you should ensure you visit a doctor for proper prognosis.