myoclonus

myoclonus /my·oc·lo·nus/ (mi-ok´lo-nus) shocklike contractions of a muscle or a group of muscles.myoclon´ic

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essential myoclonus  myoclonus of unknown etiology, involving one or more muscles and elicited by excitement or an attempt at voluntary movement.

intention myoclonus  that occurring when voluntary muscle movement is initiated.

nocturnal myoclonus  nonpathological myoclonic jerks occurring as a person is falling asleep or is asleep.

palatal myoclonus  rapid rhythmic, up-and-down movement of one or both sides of the palate, often with ipsilateral synchronous clonic movements of the face, tongue, pharynx, and diaphragm muscles.

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my·oc·lo·nus (m-kl-ns)

n.

A sudden shocklike twitching of muscles or parts of muscles without any rhythm or pattern, occurring in various brain disorders.

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myo·clonic (m-klnk) adj.

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Myoclonus

Involuntary contractions of a muscle or group of muscles.

Mentioned in: Anoxia

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myoclonus

[mī′ōklō′nəs]

Etymology: Gk, mys muscle; + klonos, contraction

a spasm of a muscle or a group of muscles. myoclonic, adj.

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myoclonus [mi″o-klo´nus]

shocklike contractions of part of a muscle, an entire muscle, or a group of muscles; usually a manifestation of a convulsive disorder. adj., adj myoclon´ic.

A single myoclonic arm or leg jerk is normal when the person is falling asleep. Myoclonic jerks are severe with grand mal seizures. From Jarvis, 1996.

palatal myoclonus a condition characterized by a rapid rhythmic movement of one or both sides of the palate.

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myoclonus,

n a spasm of muscle or group of muscles.

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myoclonus

repetitive, rhythmic contractions of a group of skeletal muscles, persisting in sleep. The result of encephalitis or myelitis caused by distemper virus in dogs. Called also canine chorea, flexor spasm and tremor syndrome.

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familial reflex myoclonus

a familial disease seen in young Labrador retriever puppies; myoclonus is followed by a generalized extensor rigidity and opisthotonos.

inherited congenital myoclonus

inherited as a recessive trait in Polled Hereford cattle; at birth affected calves are unable to stand because of myoclonic jerks to skeletal muscles in response to external stimuli; affected calves are not viable. One of the diseases originally classified together as neuraxial edema.

palatal myoclonus

a condition characterized by a rapid rhythmic movement of one or both sides of the palate.

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myoclonus

Lightning movement Neurology A rapid involuntary nonrhythmic spasm that can occur spontaneously at rest, in response to sensory stimulation, or with voluntary movements; myoclonias are symptoms and not, per se, diseases a sui generis Management Clonazepam, valproic acid. See Baltic myoclonus, Posthypoxic ischemic myoclonus, Sleep-related myoclonus.

Myoclonus types

Essential myoclonus Idiopathic/non-progressive, eg restless legs syndrome

Physiologic myoclonus Associated with sleep jerks and hiccups

Epileptic myoclonus Associated with epilepsy and

Symptomatic myoclonus Associated with encephalopathy, spinocerebellar degeneration, metabolic, toxic, or viral encephalopathy or trauma