spasm(redirected from Hemifacial spasm)
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spasm,involuntary rigid muscle contraction, often persistent and often accompanied by pain. It usually has some underlying physical cause such as disease, strain, or injury to the muscle or nearby tissues, impairment of circulation, or a disturbance of body chemistry. The spasm may be confined to one group of muscles or it may be severe and fairly generalized, as in convulsionsconvulsion,
sudden, violent, involuntary contraction of the muscles of the body, often accompanied by loss of consciousness. It is not known what causes the abnormal impulses from the brain that result in convulsive seizures, since the disturbance may arise in normal brain
..... Click the link for more information. . Painless localized spasms are called tics. These purposeless movements, usually of some part of the face, may begin as purposeful movement in response to some stimulus but eventually are carried out automatically, apparently without reason. They may disappear spontaneously after a time, or may require the elimination of some physical or psychic cause.
an involuntary tonic contraction (cramp) of a muscle or group of muscles. Spasms may affect striated skeletal muscles (for example, with certain paralyses) or smooth muscles. Subject to spasms are the smooth muscles of the vascular wall (for instance, during angina pectoris), the bronchi, the esophagus (cardiospasm), and the intestine. Skeletal-muscle spasms make movement difficult, and smooth-muscle spasms disrupt various functions of organs.
a sudden involuntary muscular contraction marked by extreme tension. Two types of spasms are distinguished: tonic and clonic. In tonic spasm, the tension persists for a long time, and in clonic spasm, there are synchronous jerking muscular contractions, which may be diffuse or limited. Spasms of different muscle groups are designated by specific terms, for example, trismus (spasm of the masticatory muscles) and blepharospasm (spasm of the ring muscle of the eye). Clonic spasms of the entire body are sometimes called convulsions.
Spasm may arise spontaneously or as a reaction to external influences, for example, spasm of the gastrocnemius muscles after chilling in water. It may also result from internal influences, for example, tension of the abdominal muscles in peritonitis. Spasm may be a manifestation of epilepsy, eclampsia, spasmophilia, inflammation, brain tumor and trauma, and many other disorders. In addition to spasm of striated muscles, there is spasm of smooth muscles, for example, cardiospasm and pylorospasm. In children, spasm is most common at a very early age, owing to the structure and functioning of the brain at this stage of life; it results from infection, poisoning, trauma, and various psychogenic factors.
Spasm is treated by caring for the underlying disorder and by administering such anticonvulsants as phenobarbital, primidone, and diphenylhydantoin. The affected person should get sufficient sleep and should abstain from alcohol.
V. A. KARLOV