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1. Repetitive, often regular, oscillatory movements caused by alternate, or synchronous, but irregular contraction of opposing muscle groups; usually involuntary. 2. Minute ocular movement occurring during fixation on an object. [L. a shaking]
- alcoholic withdrawal t. intention t. present in the withdrawal period of one of two types: 1) a t. of greater than 8 Hz, with continuous antagonistic muscle activity, and 2) a t. of less than 8 Hz, with intermittent spontaneous antagonistic muscle activity.
- alternating t. a form of hyperkinesia characterized by regular, symmetric, to-and-fro movements (at about 4 per second) that are produced by patterned, alternating contraction of muscles and their antagonists.
- alternative t. a coarse, low frequency (3–8 Hz) pathologic t. produced by alternating contraction of muscles and their antagonists; seen with Parkinson disease and kinetic predominant action t..
- coarse t. a t. in which the amplitude is large and the oscillations are usually irregular and slow.
- continuous t. SYN: persistent t..
- essential t. an action t. of 4–8 Hz frequency that usually begins in early adult life and is limited to the upper limbs and head; called familial when it appears in several family members.
- familial t. SYN: heredofamilial t..
- flapping t. SYN: asterixis.
- head tremors SYN: head-nodding.
- heredofamilial t. [MIM*190300] a benign t. inherited as a dominant character; it may be a rapid oscillation resembling that seen in thyrotoxicosis, a coarse t. during rest and inhibited by a voluntary effort, or one which appears only upon movement; of autosomal dominant inheritance. SYN: benign essential t., familial t..
- hysterical t. usually an intermittent, coarse, irregular t., limited to one limb. SYN: psychogenic t..
- intention t. a t. that occurs during the performance of precise voluntary movements, caused by disorders of the cerebellum or its connections. SYN: action t., kinetic t., volitional t. (2).
- passive t. SYN: resting t..
- persistent t. a t. that is constant, whether the subject is at rest or moving. SYN: continuous t..
- postural t. t. present when the limbs or trunk are kept in certain positions and when they are moved actively, usually due to near-synchronous rhythmic bursts in opposing muscle groups. SYN: static t..
- psychogenic t. SYN: hysterical t..
- resting t. a coarse, rhythmic t., 3–5 Hz frequency, usually confined to hands and forearms, that appears when the limbs are relaxed, and disappears with active limb movements; characteristic of Parkinson disease. SYN: passive t..
- static t. SYN: postural t..
- wing-beating t. a coarse, irregular t. that is most prominent when the limbs are held outstretched, reminiscent of a bird flapping its wings; due to up and down excursion of arm at abducted shoulder. Seen mainly with Wilson disease.
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trem·or 'trem-ər n a trembling or shaking usu. from physical weakness, emotional stress, or disease <\tremors of the hands>
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n.
a rhythmical and alternating movement that may affect any part of the body. The physiological tremor is a feature of the normal mechanism for maintaining posture. It may be more apparent in states of fatigue or anxiety or when the thyroid gland is overactive. Essential tremor is slower and particularly affects the hands and arms when held out or holding a teacup. It can be embarrassing and inconvenient but it is not accompanied by any other symptoms. A similar tremor may also occur in several members of one family and also in elderly people. Propranolol reduces the intensity of essential tremor. Primary orthostatic tremor affects the legs when standing still, causing unsteadiness if the position is maintained. Resting tremor is a prominent symptom of parkinsonism. An intention tremor occurs when a patient with disease of the cerebellum tries to touch an object. The closer the object is approached the wilder become the movements.
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trem·or (tremґər) [L., from tremere to shake] an involuntary trembling or quivering. tremulous adjMedical dictionary. 2011.