What does myoclonus mean?
Myoclonus is a medical term for a sudden, brief, involuntary contraction of a muscle or group of muscles. The resulting movement may resemble a twitch, jerk, or shock-like spasm and can affect a single muscle or occur throughout the body. Myoclonus has many possible causes, including developmental and degenerative neurological conditions, medication effects, metabolic disturbances, and seizure disorders; it is also a defining feature of syndromes such as myoclonic epilepsy. The term is mainly used in clinical settings, where doctors may distinguish an individual myoclonic jerk from a recurring pattern of myoclonus. It is related to the adjective “myoclonic,” as in “myoclonic seizures,” and should not be confused with a voluntary muscle movement or a general restlessness. The word's origin reflects the forceful, disordered character of the movement.
nounA sudden, involuntary contraction or jerking of a muscle or group of muscles. Myoclonus can occur as an isolated symptom or as part of a neurological disorder, including epilepsy.
- A sudden, brief, involuntary contraction of a muscle or group of muscles.
- A recurring or generalized pattern of such involuntary muscle jerks, especially as a feature of a neurological disorder.
"The patient experienced brief myoclonus whenever the lights flickered."
"The neurologist asked whether the patient had noticed episodes of myoclonus during sleep."
"Myoclonic seizures caused the infant's arms to jerk suddenly and briefly."
The standard medical plural is “myocloni,” as in a description of recurrent involuntary jerks.
"The examination revealed frequent myocloni in both upper limbs."
Myoclonus is a muscle movement with its own dramatic name: it comes from Greek roots meaning “muscle” and “turmoil.”
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does myoclonus come from?
Myoclonus combines the combining form myo-, from Greek mys, meaning “muscle,” with a form related to Greek klonos, meaning “turmoil” or “commotion.” The compound was developed in medical usage to describe an involuntary muscular movement. Its elements are reflected in related medical words such as myology, myocyte, and clonus.
Related word forms
How myoclonus is actually used
This is primarily medical terminology. In clinical writing, “myoclonic jerk” often refers to an individual movement, while “myoclonus” can denote the symptom or condition more generally. The adjective is “myoclonic.”