Myoclonus (myo- "muscle", clonus "spasm") describes a medical sign and, generally, is not a diagnosis of a disease.
A very rare form includes the diaphragmatic flutter, the Belly Dancer's Syndrome,[2]: 2 or Van Leeuwenhoek's disease.
[2]: 3 Studies show that possible causes include disruptions within the central or peripheral nervous systems, anxiety, nutritional disorder, and certain pharmaceuticals.
[citation needed] Myoclonic seizure can be described as "jumps" or "jolts" experienced in a single extremity or even the entire body.
The feeling experienced by the individual is described as uncontrollable jolts common to receiving a mild electric shock.
Familiar examples of normal myoclonus include hiccups and hypnic jerks that some people experience while drifting off to sleep.
Myoclonus may also develop in response to infection, hyperosmolar hyperglycemic state, head or spinal cord injury, stroke, stress, brain tumors, kidney or liver failure, lipid storage disease, chemical or drug poisoning, as a side effect of certain drugs (such as tramadol,[6] quinolones, benzodiazepine, gabapentin, sertraline, lamotrigine, opioids), or other disorders.
Benign myoclonic movements are commonly seen during the induction of general anesthesia with intravenous medications such as etomidate and propofol.
Jerks of muscle groups, much of the body, or a series in rapid succession, which results in the person jerking bolt upright from a more relaxed sitting position is sometimes seen in ambulatory patients being treated with high doses of morphine, hydromorphone, and similar drugs, and is possibly a sign of high and/or rapidly increasing serum levels of these drugs.
Scientists believe that some types of stimulus-sensitive myoclonus may involve overexcitability of the parts of the brain that control movement.
Receptors that appear to be related to myoclonus include those for two important inhibitory neurotransmitters: serotonin, which constricts blood vessels and brings on sleep, and gamma-aminobutyric acid (GABA), which helps the brain maintain muscle control.
Other receptors with links to myoclonus include those for glycine, an inhibitory neurotransmitter that is important for the control of motor and sensory functions in the spinal cord, and those affected by benzodiazepines, a variety of medication that usually induces sleep.
Concerning more serious conditions, the complex origins of myoclonus may be treated with multiple drugs, which have a limited effect individually, but greater when combined with others that act on different brain pathways or mechanisms.
Some studies have shown that doses of 5-hydroxytryptophan (5-HTP) leads to improvement in patients with some types of action myoclonus and PME.
The chemical messenger responsible for triggering the involuntary muscle contractions is blocked by the Botulinum toxins of the Botox.
[10] Surgery is also a viable option for treatment if the symptoms are caused by a tumor or lesion in the brain or spinal cord.
In severe cases, particularly those indicating an underlying disorder in the brain or nerves, movement can be extremely distorted and limit ability to normally function, such as in eating, talking, and walking.
However, the prognosis for more simple forms of myoclonus in otherwise healthy individuals may be neutral, as the disease may cause few to no difficulties.
Identifying whether or not abnormalities in these pathways cause myoclonus may help in efforts to develop drug treatments and diagnostic tests.
[12] The word myoclonus uses combining forms of myo- and clonus, indicating muscle contraction dysfunction.
The variant stressing the -oc- syllable is the only pronunciation given in a half dozen major American dictionaries (medical and general).