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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diseases affecting the cerebellum typically cause ataxia, coupled with dysmetria and tremor. Dysmetria is a condition in which there is improper measuring of distance in muscular acts; hypermetria is overreaching (overstepping) and hypometria is underreaching (understepping). Tremor refers to an involuntary, rhythmic, oscillatory movement of a body part. The tremor of cerebellar disease typically is exaggerated by goal-oriented movements (intention tremor). Cerebellar lesions also often cause loss of the menace response, despite the presence of normal vision. The anatomic basis for this phenomenon is obscure. The principal disease affecting the cerebellum in cats is cerebellar hypoplasia due to in utero infection with the panleukopenia virus. This disease will be discussed here. Neurologic signs of cerebellar involvement also may be seen in association with those diseases that affect the CNS multifocally. In these cats, there may be additional signs indicating involvement of other anatomic areas or the cerebellar deficits may occur alone (see discussion of multifocal diseases in Multiple Neurologic Deficits: Inflammatory Diseases [page 426] and Multiple Neurologic Deficits: Noninfectious Diseases [page 440]).
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PMID:Ataxia, dysmetria, tremor. Cerebellar diseases. 180 62

Serial postoperative magnetic resonance (MR) studies were obtained in 21 patients who underwent somatotopically placed stereotactic radiofrequency (rf) ventralis lateralis thalamotomy for the control of movement disorders. The MR studies were reviewed to determine the MR characteristics of early-phase (less than or equal to 7 days) and late-phase (8 days to 5 months) lesions. Surgery was performed for the control of parkinsonian tremor (14 cases), intention tremor (six cases), and essential tremor (one case). Single rf lesions were made with an electrode (1.6 mm in diameter, 3 mm in tip length) heated to 78 degrees C for 60 seconds. On MR images of the lesions, three distinct concentric zones were identified, described as follows (from the center outward). Zone 1 gives increased signal on long-relaxation time (TR) (T2-weighted) MR images in early- and late-phase lesions and decreased signal on short-TR (T1-weighted) MR images in early-phase lesions only. Zone 2 gives decreased signal on long-TR (T2-weighted) images in early- and late-phase lesions; it gives isointense signal on short-TR (T1-weighted) images in early-phase lesions only. Zone 3 gives increased signal on long-TR (T2-weighted) images in early-phase lesions only and decreased signal on short-TR (T1-weighted) MR images in early-phase lesions only. It is considered that in early-phase lesions, Zone 2, with a mean diameter of 7.3 mm on axial long-TR (T2-weighted) imaging, represents an area of hemorrhagic coagulation necrosis. In late-phase lesions, Zone 2, with a mean diameter of 5.0 mm on axial long-TR (T2-weighted) imaging, represents hemosiderin deposition. Zone 3 likely represents edema, and this zone disappears between the early and late periods. From regression analysis, lesion size began to stabilize at approximately 7 months with a mature lesion diameter of 3.3 mm. Long-term follow-up monitoring (median 16 months) showed good tremor control. Based on clinical and radiological findings, the authors conclude that forms of hemoglobin are suitable markers to assess the size of rf lesions. Serial MR imaging provides a noninvasive means of studying the evolution of rf thalamotomy lesions.
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PMID:Sequential magnetic resonance imaging following stereotactic radiofrequency ventralis lateralis thalamotomy. 191 16

Actual phenomena of various types of involuntary movements listed below were demonstrated by moving pictures, which were followed by comments on symptomatology, in particular the fundamental characteristics of an individual involuntary movement. These characteristics are the essence of each involuntary movement, and it is necessary to recognize both its phenomenon itself and its accumulated knowledge in order to realize and interpret the involuntary movement. The following involuntary movements are treated: (1) typical tremor-at-rest in paralysis agitans, (2) atypical parkinsonian tremor, (3) essential tremor, (4) chorea, (5) ballism, (6) athetosis, (7) choreoathetosis, (8) dystonia, (9) spontaneous myoclonus at rest, (10) intention or action myoclonus, (11) intention tremor and (12) hyperkinesis.
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PMID:[Symptomatology of the involuntary movement]. 201 97

Tumours of the pineal region have historically been difficult to remove safely. Only recently have large series of successful pineal area operations been reported, and there are many advocates for surgical reticence with these tumours. We report a case of a 20-year-ol women whose pineal region tumour was irradiated, whereupon a unilateral low-frequency resting and intention tremor developed. Following resection of the lesion, a vascular hamartoma, the tremor virtually disappeared. We believe the tremor was secondary to radiation induced tumour shrinkage and distortion of the mesencephalon. This case is demonstration of the importance of exploration and histological verification of pineal region tumours.
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PMID:"Rubral" tremor following radiation of a pineal region vascular hamartoma. 236 Apr 73

We investigated the effect of arotinolol, a new peripherally acting beta-adrenergic blocker, in 15 patients with essential tremor. The patients received 30 mg per day of arotinolol for 8 weeks. Accelerometer readings showed a significant reduction in amplitude of postural tremor after treatment. Action tremor also improved to essentially the same degree as postural tremor. The present findings support the view that the therapeutic effect of beta-blockers in essential tremor is mediated by peripheral beta-adrenergic receptors.
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PMID:Treatment of essential tremor with arotinolol. 245 Nov 92

Forty-seven railroad workers who were exposed to polychlorinated phenols, including dioxin (TCDD), during 1979 while cleaning up the chemical spillage following damage to a tank car filled with these chemicals were followed medically for the subsequent 6 years. Two committed suicide. The initial neurological complaints included a sense of fatigue and muscle aching, both of which have been reported in other individuals following dioxin exposure. On detailed neurological examination in December, 1985, 24 of 45 had dystonic writer's cramp and/or other action dystonias of the hands. None of the involved individuals had a family history of dystonia, and all 24 dated the onset of the dystonia to the first 2 to 3 years subsequent to their toxic exposure. The dystonias varied in severity but were usually mild. No other types of dystonic involvement were recognized. Thirty-five of the 45 individuals also manifested postural and terminal intention tremor which resembled benign essential tremor. None of the involved individuals had a family history of tremor, and all 35 of those affected dated the onset of the tremor to some time subsequent to their toxic exposure. Forty-three of 45 patients had histories and findings suggestive of peripheral neuropathy. This is the first report relating any type of dystonia to prior dioxin exposure and the first report relating action dystonia, such as dystonic writer's cramp, and postural/terminal intention tremor, to toxic exposure of any type.
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PMID:Dystonia and tremor following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin. 284 55

Two patients with long-standing intention tremor that was interfering with their ability to maintain employment were treated with glutethimide. In both patients, this agent successfully suppressed tremor at doses of 1,000 mg and 4,000 mg per day. Glutethimide has been taken for as long as 14 years in one patient without evidence of side effects.
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PMID:The use of glutethimide for treatment of essential tremor. 292 3

We reported three cases with involuntary movements following pontine hemorrhage. All cases had various symptoms indicating brain-stem lesions, but the consciousness and motor functions were not severely disturbed. CT scans showed a small hematoma localized in unilateral pontine tegmentum in all cases. Intention tremor developed six to ten months after the hemorrhage when the initial neurological symptoms were almost relieved. Electromyogram (EMG) showed a rhythmic 3-4 Hz alternating or synchronized tremor pattern which was induced by finger-nose test and arm stretching. In one case which had showed bilateral horizontal gaze palsy indicating bilateral PPRF involvement in the acute stage, spontaneous vertical nystagmus was observed when the tremor developed. Electronystagmogram (ENG) and its differential calculus showed a pendular nature of the eye movement. This abnormal eye movement did not disappear while the patient was asleep. This case also developed a palatal myoclonus in the chronic stage. Magnetic resonance images (MRI's) obtained one to three years after the hemorrhage revealed a lesion localized in hemipontine tegmentum. The responsible lesion of these involuntary movements was thought to be located in pontine tegmentum from the MRI findings. The functional Prognosis of small hemorrhage in unilateral pontine tegmentum is generally good, but care should be taken for the possibility of late development of various types of involuntary movement.
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PMID:[Three cases of involuntary movements following pontine hemorrhage]. 319 Sep 36

1. The relation between changes in motor cortex neural (MCN) discharge and the development of limb ataxia during cerebellar dysfunction was studied in 4 Cebus monkeys. Elbow movements with decreased accelerations or with tremor were produced by reversible cerebellar nuclear cooling. Discharge from 160 neurons was analyzed in detail. 2. During cerebellar cooling 37 of 80 neurons that discharged before movement onset decreased their phasic, but not their tonic, activity. This could not be explained by decreased peak velocities during cerebellar cooling. It is suggested that this decreased phasic discharge is related to the less abrupt onset and smaller magnitude of agonist EMG activity, and to the decreased initial accelerations, without decreased peak velocities, observed in limb movements during cerebellar dysfunction. This view implies that the cerebellum is involved in some way in the generation of commands to agonist alpha-motoneurons. 3. No evidence was found that 3- to 4-Hz cerebellar intention tremor is driven by a purely central oscillator. All 28 neurons that discharged strongly in relation to cerebellar tremor in movements responded strongly and reciprocally to limb perturbations. 4. A number of changes were observed during cerebellar nuclear cooling in kinematically related neural discharge associated with disordered elbow movements: an increase in discharge of some velocity- and acceleration-like neurons, a decrease in (reciprocal) inhibition, and a shift from an acceleration-like to a velocity-like discharge in some neurons. 5. Fourteen of 29 neurons with muscle-like discharge patterns discharged in a servoassistance-like manner during cerebellar dysfunction that was consistent with them contributing to tremor. 6. The results indicate that a variety of disorders, i.e., in the generation of central commands that initiate movements and in the regulation of the gain and phase of proprioceptive feedback, contribute to the development of limb ataxia during cerebellar dysfunction.
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PMID:Changes in motor cortex neural discharge associated with the development of cerebellar limb ataxia. 319 58

The influence of alterations in visual guidance and somaesthetic sensory inputs was studied in five patients with kinetic and postural tremor characteristic of cerebellar impairment. The patients performed wrist flexion-extension movements or movements about the shoulder with or without visual guidance. Different types of mechanical loads were applied to oppose the wrist movements. The tremor was greatest when the patients used visual cues to guide movements. Kinetic tremor was substantially suppressed during performance of similar movements that were not guided directly by vision. Viscous loads suppressed the tremor nearly linearly, whereas constant loads opposing extension enhanced the tremor. The postural tremor was not observed during isometric contractions. These results support the view that processing of visual information contributes to the impairment of movement in disorders with cerebellar-type tremor and that certain somaesthetic inputs can selectively influence the generation of postural tremor.
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PMID:Visual and mechanical control of postural and kinetic tremor in cerebellar system disorders. 320 2


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