tremor

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tremor

a minor earthquake

Tremor

 

an involuntary trembling of the entire body or parts of it. Tremors are characteristically rhythmic and stereotypic; usually they have a narrow range, most often affecting the fingers, eyelids, tongue, lower jaw, and head. In healthy subjects, tremors may be caused by muscular strain, emotional excitement, or exposure to cold. Pathological tremors may be symptoms of chronic alcoholism, thyrotoxicosis, neurotic states, acute infections, and such diseases as parkinsonism. The symptom is treated by treating the primary disease.

Eye tremor is an involuntary rapid movement of the eyeball in relation to the optic axis; its frequency is from 20 to 150 Hz, and its amplitude, from 5 to 15 seconds of arc. Visual perception itself depends to a significant degree on eye tremor, which produces constant changes in the illuminance of certain photoreceptors—that is, the photoreceptors located at the variously illuminated points of the retinal periphery. An image whose projection on the retina remains completely stable for more than a few seconds ceases to be perceived by the visual centers of the brain.

tremor

[′trem·ər]
(geophysics)
A minor earthquake. Also known as earthquake tremor; earth tremor.
(medicine)
Involuntary, rhythmic trembling of voluntary muscles resulting from alternate contraction and relaxation of opposing muscle groups.
References in periodicals archive ?
These scores represent action tremor, which we hereafter refer to simply as tremor.
In conclusion, the evidence presented suggests that the VIM DBS is an important site for reducing action tremor and improving force control in PD.
Lead is a ubiquitous toxicant (Konat and Clausen 1974; Schroeder and Tipton 1968), and laboratory animals and humans exposed to high levels of either inorganic or organic forms of lead develop neurologic disorders in which action tremor is prominent (Booze et al.
Postural and action tremors (tremors that occur during movement) are caused by multiple health problems.