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

The long-term results of 12 stereotaxic operations on 11 multiple sclerosis patients with incapacitating intention tremor were evaluated and compared with the experiences of other authors. The selection of the patients, the criteria applied for the success and the length of the follow-up period influenced the reported results. Considering not only the relief of the intention tremor but the overall performance after the operation only a certain group of patients seemed to profit by neurosurgical treatment. Applying this criterion of overall performance and evaluation only 3 out of 11 patients in our series had real benefit from the operation. The reasons for this small number of good or moderate results are given with brief discussion of some of the cases. History, course and fatal outcome of one patient are presented in detail together with the neuropathological findings. According to the literature and the limited number of our own cases the following indications for stereotaxic operations on MS patients can be established: 1. Tremor and hyperkinetic movements should be the dominant features of the symptomatology. 2. The overall performance should be essentially improved by the operation. 3. Patients in the terminal stage of the disease gain little from the procedure, whereas patients with longstanding more benign course are the best candidates.
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PMID:[Indications for stereotaxic neurosurgery of patients with multiple sclerosis (author's transl)]. 5 94

Tremor can be categorized into three general types: resting, action, and intention, Each requires different therapy. Resting tremor is present when the hands are at rest; it disappears with movement. It is characteristic of Parkinson's disease and responds to treatment with L-dopa either alone or in combination with a decarboxylase inhibitor. Action tremor is maximal when the hands are outstretched to the front; it may persist during movement. It is not rare and is often misread as a sign of Parkinson's disease. Propranolol is beneficial. Intention tremor occurs with movement and is characteristic of cerebellar disease. Pharmacologic agents are not helpful. The only known effective treatment is stereotaxic surgery.
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PMID:The shaking patient. Diagnosis and management of tremor. 83 91

Normal voluntary movements are considered to be of two kinds, or to involve two components, (i) a ballistic or "open-loop" type, which are preprogrammed and executed without reference to current sensory information and (ii) a corrective or "closed-loop" type, whose course or termination are regulated by such information. In a previous paper it was suggested that Parkinsonism disrupted the first kind of movement, but intention tremor did not. In the present paper three experiments designed to test this hypothesis are described. Subjects were tested on an acquisition-tracking task using an oscilloscope display and joystick control, and measurements were made of the duration, velocity and error of their initial movements to acquire the target. Parkinsonian movements were found to be considerably different from normal in that (a) most movements by this group lasted longer than the reaction time for their initiation, as if including some secondary correction in their execution, (b) the rate of movement was not varied for different amplitudes (so keeping the duration fairly constant) as in normal subjects, but rather movements of all amplitudes were made at a constant slow rate, so that duration increased markedly with the larger steps, (c) error increased disproportionately as the velocity of movement increased; in particular any movements completed in one reaction time or less tended to be wildly inaccurate, (d) removing either the target or the response marker from the screen at the beginning of a movement had a significant effect, making it shorter in duration and smaller in amplitude than those usually produced with both markers visible all the time. Parkinsonian subjects showed no improvement in performance with repeated attempts at one movement over a whole sequence, so their deficit appears to be stable even after practice on a known fixed task. These results are interpreted as supporting the hypothesis that Parkinsonism interferes with the generation of accurate ballistic action which are characteristic of normal skilled movement. Tremor subjects in general resembled normal control subjects in their initial acquistion movements, but their accuracy was less with the larger steps.
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PMID:Visual "closed-loop" and "open-loop" characteristics of voluntary movement in patients with Parkinsonism and intention tremor. 99 Aug 99

Since the description by Galen in the 2nd Century, A.D., clinical neurology has acknowledged the existence of two types of tremor: that which occurs at rest and that occuring during the execution of movement. With the help of refined methods of analysis, E.M.G. and cinephotography, the authors have carried out a detailed clinical assessment in more than 400 patients. The basic criterion used to define a tremor was the classical definition of Dejerine: "An involuntary, rhythmical and symmetrical movement about an axis of equilibrium." As a result of this study, the conclusion has been reached that there are two types of tremor: postural tremor and tremor of attitude. Both are present while the limb remains immobile, whether by wilful design or when at rest in a position of posture and subject only to the action of gravity. During voluntary movement, tremor is not present. Irregular, asymmetrical and non-rhythmic oscillations may appear however - as in so-called intention tremor, of cerebellar origin - but this abnormal movement can hardly be called a real tremor. It is merely a manifestation of ataxia. As a consequence of this study, it is suggested that further understanding of the basic mechanism of tremor can be reached by the investigation of the central neural structures which are involved in the physiology of posture and attitude.
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PMID:Semiology of Tremors. 109 80

A method of measuring and analysing intention tremor using a linear accelerometer is described. Reasons are given for measuring this particular parameter of the tremor, for using this specific energy conversion device, and for employing the particular form of analysis. A comparison of the numerical values obtained for the amount of tremor activity, compared with a corresponding clinical grading, is made for 30 patients with intention tremor due to a variety of pathological causes. It is shown that the method gives clear correlation with the clinical assessments, although certain discrepancies are noted, and their importance discussed.
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PMID:Intention tremor--a method of measurement. 115 5

Thirty-one patients with intention tremor due to a variety of causes were subjected to measurements of their intention tremor. The effect of varying amounts of lead weights on the amount of limb tremor recorded was noted. It is concluded that simple methods of treatment may be of benefit, and that an objective method of measuring intention tremor overcomes many of the difficulties of a clinical trial of this type. The method described yields quantifiable data which can be subjected to statistical analysis to help overcome the problem of variability. Bias in the results due to practice or fatigue effects has proved negligible. An optimum amount of lead, which was usually between 600 and 840 g, has been noted.
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PMID:Application of an objective method of assessing intention tremor - a further study on the use of weights to reduce intention tremor. 115 6

Six patients with Parkinson's disease, six patients with essential or intention tremor, and nine controls were tested on a step-tracking task using a joystick control and oscilloscope display. Tremor subjects resembled controls in making an initial ballistic movement followed by (defective) corrections, and took longer than the controls to reach the target with small amplitude jumps, but not with larger ones. The reverse was true for parkinsonian subjects, who acquired the target with slow corrective movements only. This suggests that two kinds of movement available to normal people are selectively impaired in these disorders; ballistic movements in Parkinson's disease and small amplitude corrective movements in the other disorders.
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PMID:Ballistic and corrective movements on an aiming task. Intention tremor and parkinsonian movement disorders compared. 116

A set of tests measuring tremor with an accelerometer has been developed to assist in objectively evaluating clinical trails. An experiment was designed to examine the consensual validity of the test measures for Resting, Sustention and Static Intention Tremor for 10 multiple sclerosis patients and 10 parkinsonian patients. Motion pictures of the patients performing the tremor tests were viewed by a senior neurologist who rated tremor using a nine-point ordinal scale. Comparisons made between the quantitative measures of tremor and the neurologist's ratings of tremor show that the tests are consensually valid. The methodology of this experiment may prove useful for examining in the future the consensual validity of new clinical instruments useful for evaluating trails.
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PMID:Validity of quantitative tests measuring tremor. 118 Mar 53

A marked effect of stereotaxic thalamotomy on intention tremor is described and a neurophysiological interpretation is offered. Tremor-generating activity seems to start in the ventral intermediate nucleus (VIM) of the thalamus, as revealed by recording of the unitary activity through a microelectrode at the tip of the insertion needle, after diminution of facilitatory input due to pathology of the cerebellum or its efferent pathway to the cerebrum. This secondary change within the VIM and the loss of facilitatory input leads to an intention tremor as one of the cerebellar symptoms seen in various neurological diseases.
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PMID:Analysis of intention tremor. 132 Apr 88

In the past, intention tremor has responded well to selected neuroablative procedures; however, objective symptomatic and functional outcomes of ventralis lateralis (VL) thalamotomy specifically for intention tremor in the post-computerized tomography era has rarely been reported. This series explored the symptomatic and functional impact of VL thalamotomy on 14 patients presenting at the Mayo Clinic with severe, refractory intention tremor due to multiple sclerosis (five patients), trauma (four patients), or stroke (five patients). General neurological examinations, psychometric evaluations, speech pathology assessments, and neuroradiological scans were performed. Pre- and postoperative disability were graded according to a modified form of an established rating scale for tremor. All patients received VL radiofrequency thalamotomies utilizing neurophysiological recording and stimulation control. Contralateral targeted upper-extremity tremor remained symptomatically absent or markedly reduced in 81.8% of cases (mean follow-up period 23.4 months). The median disability score was reduced by 12 points (0.02 less than p less than 0.05). Persistent surgical morbidity was limited to two patients with mild, nondisabling dysarthrias. One elderly patient died of pulmonary complications 2 weeks postoperatively. There were no reported surgically induced exacerbations in multiple sclerosis; however, some of these patients exhibited difficulties with electrophysiological localization. These results compare favorably with those reported in the literature and confirm that stereotactic VL thalamotomy for debilitating intention tremor carries a low surgical risk and can be an effective treatment option for properly selected patients.
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PMID:Symptomatic and functional outcome of stereotactic ventralis lateralis thalamotomy for intention tremor. 842 Dec 18


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