Relief Of Tremor Research Articles

Motivational slow negative potential shift (CNV) related to thalamotomy.

The alteration of cortical electrical activity induced by imperative stimulation following warning stimulation, contigent negative variation (CNV), and psychological changes following thalamotomy for relief of intractable pain (CM) and tremor (VL) are studied, since CNV has a close relationship with the degree of psychological activity. Ventrolateral thalamotomy does not have any effect on the amplitude of cortical CNV, but the ventromedioposterior part of the centre median has a generating action of CNV in itself and it has facilitatory effects upon cortical CNV. According to these results, the effective mechanism of centre median thalamotomy for relief of intractable pain is caused by suppression of attention and expectancy for exogenous stimuli following lesions of the centre median.

The antiparkinsonian efficacy of bromocriptine.

The antiparkinsonian activity of bromocriptine, a presumed dopaminergic receptor agonist, was investigated in monkeys with surgically induced tremor and in a group of parkinsonian patients. A single administration of bromocriptine resulted in a dose-dependent relief of tremor in monkeys. Repeated administration enhanced this effect. Only mild abnormal involuntary movements were observed and only after repeated administration. Eleven patients with Parkinson's disease were treated with bromocriptine (mean dose, 26.4 mg a day). Clinically obvious improvement was noted in one or more of the cardinal signs of the disease in six patients (responders). No obvious improvement in any of the cardinal signs was noted in the remaining five patients (nonresponders). Clinically, the responders were older and more severely affected and had been on a higher dose of levodopa. However, they had had the disease for a shorter period. It is suggested that failure to respond to bromocriptine may be related to a decrease in the sensitivity of postsynaptic dopaminergic receptors.

Physiologically Defined VIM Nucleus

In the course of stereotactic surgery for some 100 parkinsonian patients, correlative study of recording and stimulation has been done in and around the thalamic nucleus ventralis intermedius (VIM) under local anesthesia. The VIM nucleus is roughly identified either by the increase of neural noise level or radiological measurement. More accurately, in the thus identified VIM, sensory neurons related to kinesthetic sense of the contralateral extremity were found in about half of the cases. Electrical stimulation of this point at threshold intensity produced paresthesia on the contralateral area around its receptive field. With increased stimulus intensity, increment of grouping discharge in EMG of that part was pertinent in the majority of cases. A small localized lesion at such a thalamic point was shown to be quite effective for alleviation of tremor without any neurological, especially sensory, deficit.

Indications for stereotaxic neurosurgery of patients with multiple sclerosis (author's transl)

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.

Optimum Target for Tremor Arrest

In an attempt to further define the optimum target for abolishing tremor, 25 cases out of a series of 1,000 consecutive thalamotomies for Parkinson''s disease were selected on the basis that mere impact of electrode placement had suddenly arrested tremor. These sites were carefully plotted, and correlated with the available data from physiological exploration. They were grouped in a relatively restricted area, extended from 2 to 8 mm in front of PC, from 8 mm above to 2 mm below the AC-PC line in the sagittal plane, and from 13 to 15 mm laterally, but densely in its posterio-inferior part. There is a soma-totopic arrangement, since tremor is sometimes exclusively arrested in one limb. These sites correspond to the area from where Gillingham and others reported rhythmic bursting activity synchronous with tremor. Stimulation with low frequency produced an increase or activation of tremor, and with higher frequencies, amelioration or suppressive response. In all cases, the radiofrequency lesion at this site produced a long-lasting relief of tremor, with no side effects. This area corresponded to the prelemniscal radiation and lemniscal sector of V.c.p., V.i.m. and posterior-basal part of V.o.p

Action of m-tyrosine in experimental models: Evidence for possible antiparkinsonian activity

The antiparkinsonian acitivity of m-tyrosine was investigated in two experimental animal models. In rats with a unilateral 6-OH-dopamine (DA)-induced lesion of the nigro-neostriatal DA pathway, the administration of d,1- or 1-m-tyrosine in combination with an extracerebral 3,4-dihydroxyphenylalanine (Dopa) decarboxylase inhibitor or with a monoamine oxidase inhibitor causes marked turning of the rat towards the intact side and mimicks the action of Dopa in this model. The present results indicate that d,1- and 1-m-tyrosine treatment results in preferential stimulation of denervated DA receptors, the 1-form probably being the active form. Pharmacological analysis involving also cerebral decarboxylase inhibition, treatment with a DA-β-hydroxylase inhibitor or a DA-receptor blocking agent, spiroperidol, indicates that m-tyramine formed from m-tyrosine was acting as a false transmitter on Dd receptors. Negative results were obtained with α-methyl-Dopa, α-methyl-m-tyrosine and 5-hydropxyptophan (5-HTP), indicating that α-methyl-DA, α-methyl-m-tyrosine and 5-hydroxytryptamine (5-HT) are poor stimulators of DA-receptor sites. In monkeys with unilateral ventromedial tegmental lesions, d,1- and 1-m-tyrosine alone or in combination with an extracerebral Dopa-decarboxylase inhibitor causes a transient relief of the tremor of the ipsilateral extremities. The tremor relief induced by m-tyrosine but not only Dopa is potentiated when the animals are pretreated with a monoamine oxidase inhibitor. In both experimental models, m-tyrosine exhibited a weaker pharmacological activity than Dopa. The results suggest that m-tyrosine could be of therapeutic value in the treatment of Parkinsonism. Unlike Dopa, m-tyrosine is not metabolized by catechol-O-methyltransferase and, owing to its weaker DA-receptor stimulation could elicit less hyperk9nesias than Dopa.

Drug-induced relief of experimental tremor in monkeys.

Drug-induced relief of experimental tremor in monkeys.

L-dopa in the treatment of Parkinsonism; a preliminary appraisal.

HE treatment of parkinsonism from the time of its first clear description by Parkinson 1~ to the modern era has been less than satisfactory. Neurosurgical procedures directed at the pyramidal tracts ranged from the premotor cortex through the cerebral peduncles and into the spinal cord. The goal was to relieve unilaterally a single troublesome symptom, namely, tremor, leaving the problems of bradykinesia, gait, balance, posture, voice, speech, swallowing, and others untouched. Some success was obtained, usually at the price of significant weakness in the limbs involved. When the weakness diminished, as it often did following surgery, the tremor tended to recur. Neurosurgical procedures directed at the basal ganglia ushered in a whole new phase of treatment, chiefly because relief of tremor, rigidity, and poor alternating movements could be obtained without producing any weakness whatsoever. This divorced the tremor and rigidity from what had previously been thought to be their intrinsic dependence upon the great voluntary motor pathway, the pyramidal tract. Reports from neurosurgical centers throughout the world concurred on this point. Our own experiences have been extensively reported and show that alleviation of tremor and rigidity can be obtained in 85% to 90% of properly selected patients with cryosurgical lesions directed at the ventrolateral and posteroventrolateral nuclei of the contralateral thalamus. ~ Acceptable mortality and morbidity figures were also reported from our clinic in a series of nearly 3000 eases. 11 The mortality in that series of consecutive operations done for parkinsonism

Relief of intention tremor by thalamic surgery.

Relief of intention tremor by thalamic surgery.

L-dopa for parkinsonism

Existing anti-Parkinsonian drugs help 60–80% of patients,1 mainly by reducing rigidity. Stereotaxic surgery also reduces rigidity but has proved particularly helpful in the alleviation of tremor.2 Evidence is now accumulating that a new drug, L-dopa (l-dihydroxyphenylalanine), is useful in the management of Parkinsonism. Its salient therapeutic action is the reduction of hypokinesia, making it easier to initiate voluntary movement. It also helps to control oculogyric crises, which are generally refractory to all other forms of treatment.

Stereotactic thalamotomy in the treatment of extrapyramidal disorders: criteria for selection of parkinsonian patients.

Abstract: Stereotactic thalamotomy has been performed to date on 370 patients with extrapyramidal disorders; 287 of these patients had Parkinson's disease.The proper selection of candidates for this operation, among elderly persons just as among younger ones, is essential for success. The criteria for selection of parkinsonian patients are listed, as are the contraindications for the operation in this disease.When properly selected elderly parkinsonian patients undergo accurately performed stereotactic thalamotomy, good results (complete or marked relief of tremor and/or rigidity) can be expected in about 75 per cent of the cases. Two representative case reports are included.

Relief of Intention Tremor of Multiple Sclerosis by Thalamic Surgery

The relief of postural and intention tremor of multiple sclerosis can be accomplished by infliction of a surgical lesion in the ventrolateral nucleus of the thalamus. The development of postural or intention tremor in such cases is secondary to a lesion of the cerebellodentato thalamic pathway, which results in impaired feedback of sensory communication from muscle spindles via cerebellum to the thalamus. A surgical lesion within ventrolateral thalamus abolishes communication of pathologic sensory information to the motor cortex, and thus relieves the tremor. In a series of 32 cases of intention tremor due to multiple sclerosis, the patients were subjected to thalamic surgery and followed up for one to ten years. The tremor was abolished or markedly lessened in 85% (27 of 32) of the patients in this series. There was one postoperative death; there are two patients with preexisting spastic hemiparesis who had worsening of spasticity following surgery. It is concluded that thalamic surgery is the treatment of choice of chronic or progressive intention tremor of multiple sclerosis.

Relief of intention tremor of multiple sclerosis by thalamic surgery

Relief of intention tremor of multiple sclerosis by thalamic surgery

Neurological side-effects in a series of operations on the basal ganglia.

T HIS is a s tudy of the neurological sideeffects of operations on the basal ganglia. I t is based on the correlation of clinical and radiological data obtained in a series of 650 basal ganglia operations for Parkinson 's disease. The medical l i terature shows particular concern with the optimal location of the lesion which will result in relief of rigidity and tremor. There is now almost complete agreemen t tha t the best therapeutic effects are achieved by lesions located in the area of the ventral thalamus al though the exact coordinates va ry somewhat from one author to another.l,4,5,s Hemiballismus and hemiplegia are two impor tan t complications following basal ganglia surgery. 7'9 Menta l changes following bilateral operations have also been mentioned especially by the Riechert school. 6 Informat ion regarding other neurological phenomena occasionally seen following basal ganglia stereotactic surgery is scarce. The symptoms include dystonic movements and postures, dysarthria , sensory changes and thalamic pain . One also gathers the impression that postoperat ive problems such as hemiplegia and mental changes are primarily due to true surgical complications, especially vascular softening and hemorrhages2 I t is our purpose to analyze our own series in order to discover the correlation, if any, between the radiological location of the lesions and the most common neurological side-effects. We will not concern ourselves with clinical results in terms of alleviation of t remor and rigidity except for comparison and we have eliminated those cases where the undesirable effects were the result of purely surgical complications, such as hemorrhage. This work follows closely the paper first published in 1960 by Cooper and one of

Thalamotomy for the relief of intention tremor in multiple sclerosis.

Acta Neurologica ScandinavicaVolume 38, Issue s3 p. 153-156 THALAMOTOMY FOR THE RELIEF OF INTENTION TREMOR IN MULTIPLE SCLEROSIS B. Broager, B. BroagerSearch for more papers by this authorT. Fog, T. FogSearch for more papers by this author B. Broager, B. BroagerSearch for more papers by this authorT. Fog, T. FogSearch for more papers by this author First published: October 1962 https://doi.org/10.1111/j.1600-0404.1962.tb01135.xCitations: 9 From the Neurosurgical Department, Bispebjerg Hospital, and the Neurological Department, Kommunehospitalet, Copenhagen. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume38, Issues3October 1962Pages 153-156 RelatedInformation

DIFFERENTIAL EFFECTS OF ANTIEPILEPTICS ON HIPPO-CAMPAL AND PALLIDAL AFTERDISGHARGES IN CATS

Many investigators reported that the hippocampus (HPC) was involved in cerebral and cerebellar seizure discharges and epileptiform phenomena (1-4), and it was the well known site of histological lesion which was found in approximately 50 per cent of epileptic brains (5, 6). The HPC has the lowest threshold of excitability to electrical stimulus of all the cerebral structues so far studied since reported by Kaada (1). Pathologically and electrophysiologically the sensitive structure of brain is suggested to play an essential part in the development of the epileptic seizures. Several ablation and electrophysiological experiments on the brains (7-13) have confirmed that extrapyradmidal structures play a predominant part in the mechanism of generalized convulsion, and that convulsion has not cortical origin followed with corticospinal propagation. For the relief of tremor and rigidity in extrapyramidal diseases, the surgical lesion is often made in the globus pallidus (GP) (14). Most characteristic response to electrical stimulation of GP is tremor in human (15). The present investigation was undertaken to evaluate the effects of clinically known antiepileptics quantitatively on the both hippocampal and pallidal seizures with special reference to threshold voltage and afterdischarge propagation induced by electrical stimulation of both HPC and GP.

Ocular Signs After Stereotactic Lesions in the Pallidum and Thalamus

This is a report of the occurrence of nystagmus retractorius, inferior quadrantanopia of optic tract or geniculate origin, and paresis of conjugate gaze, following localized stereotactic lesions in the central nervous system of man. These ocular phenomena were observed after the lesions were placed in the region of the pallidum or thalamus for the relief of tremor and rigidity in extrapyramidal diseases and for the relief of intractable pain. Report of Cases Case 1. —This 72-year-old white woman developed intractable postherpetic neuralgia following herpes zoster ophthalmicus on the right in August, 1958. Protamine, x-ray therapy, avulsion of the right supraorbital nerve, and undermining of the affected skin failed to produce relief. Because of persistence of the pain, she was admitted to Duke Hospital in July, 1960, for stereotactic thalamotomy. Neurological examination revealed a complete anesthesia in the distribution of the first division of the right trigeminal nerve; otherwise, it was

Effect of stimulation of the pallidum on experimental tegmental tremor in the cat.

The mechanism, responsible for the relief of Parkinsonian tremor following pallidal lesions, is obscure. The neuronal mechanisms underlying the tremor itself are not well understood at present, although evidence from several inveEtigations (2, 4, 8, 9, 11, 12, 16, 17, 19) is focussing attention on the brain stem, particularly the midbrain reticular formation, as the source of the underlying periodic neuronal activity. Spiegel and Wycis (12) have suggested that the beneficial effect of pallidotomy upon the tremor may be due to interruption of pallidofugal fibers carrying facilitating impulses to lower tremorgenetic centers. The problem of the existence of such pallidofugal impulses can be approached experimentally, since by stimulating the midbrain reticular formation in cats (2, 11, 20) and monkeys (4), one can produce a tremor which is similar to Parkinsonian tremor in several of its features (2, 11, 20) and in its response to certain drugs (4). The extent to which the neurophysiological mechanism of this experimental tremor is similar to that of Parkinsonian tremor requires further study, but a similarity of these mechanisms is suggested by the evidence cited above. The main object of the present experiments was to ascertain whether the tremor produced by stimulating the mesencephalic tegmentum in the cat can be influenced by pallidal stimulation.

COMBINED LATERAL AND VENTRAL PYRAMIDOTOMY IN TREATMENT OF PARALYSIS AGITANS

IN RECENT years there has been great interest in the surgical treatment of parkinsonism, following the work of Bucy and Case, 1 in 1939, which demonstrated that it was possible to relieve tremor by operative means. Previously it had been shown that the medical treatment of paralysis agitans was unsatisfactory. There had been long experience with various drugs, primarily those of the atropine series, which provided only transient and slight relief. The inadequacy of medical measures necessitated a more radical approach, which in the past ten years has produced a variety of surgical technics. Meyers 2 set up criteria for an ideal operative procedure for the relief of tremor, of which the following are important: The benefits to be anticipated from the operation should be commensurate with the risks involved. No impairment of function beyond that already in evidence should result from the operative procedure. Ideally, the operation should not