Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Surgical treatments for PD and ET are promising. Medial Pallidotomy, the surgical lesioning of the pallidum, often improves symptoms of long-standing PD. We enrolled twenty-seven late stage PD patients for unilateral medial pallidotomy who were then assessed by the Core Assessment Program for Intracranial Transplantation (CAPIT) protocol. One year after surgery persistent improvement was seen contralateral to the lesion in the following features: drug-induced dyskinesias (92%), akinesia (38%), rigidity (51%), and tremor (42%). Complications included transient dysarthria (7 patients), facial weakness (9 patients), limb weakness (1 patient), swallowing problems (4 patients) and intracerebral haemorrhage (1 patient). Thalamic DBS may improve tremor in PD and ET patients. Therefore, we enrolled fifteen patients (9 PD and 6 ET patients) with disabling tremor, unresponsive to medication. They were assessed by the United Parkinson's Disease Rating Scale (UPDRS) and the Tremor Rating Scale (for PD and ET patients, respectively). Three months after surgery, limb tremor contralateral to stimulation improved by 71% in PD patients and 76% in ET patients. Complications included transient paresthesias (all), confusional state (1 patient) and intracerebral bleed (1 patient). Unilateral medial pallidotomy safely improves some Parkinsonian symptoms contralateral to the lesion. Thalamic DBS may effectively and safely improve contralateral limb tremor in PD and ET.
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PMID:Surgical interventions in the treatment of Parkinson's disease (PD) and essential tremor (ET): medial pallidotomy in PD and chronic deep brain stimulation (DBS) in PD and ET. 929 83

Essential tremor is a common movement disorder. Deep brain stimulation of the VIM nucleus of the thalamus has been reported to be efficacious for reducing essential hand tremor. The effect of deep brain stimulation of the thalamus on essential head tremor has not been well studied. Therefore, we evaluated the effect of DBS of the thalamus in 38 patients with essential head tremor. Head tremor scores prior to surgery were compared with scores at 3, 6, and 12 months postimplant with stimulation "on" and "off." The 3-month evaluations were blinded for 24 patients and all others were open-label. There was a significant improvement in head tremor at all postimplant evaluations compared with baseline. Essential head tremor can be reduced with deep brain stimulation of the VIM nucleus of the thalamus and, pending the results of other controlled trials, should be considered as a treatment option for patients with disabling essential head tremor unresponsive to medication.
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PMID:Efficacy of unilateral deep brain stimulation of the VIM nucleus of the thalamus for essential head tremor. 1049 50

Chronic stimulation of the ventral intermediate nucleus (Vim) of the thalamus is highly effective for the treatment of tremor. Patients with tremor associated with Parkinson's disease and essential tremor appear to respond best. Patients with cerebellar tremors may also respond but to a lesser extent. Although tremor is improved, Vim DBS does not substantially improve the daily living activities of patients with Parkinson's disease. This is related to the lack of effect on rigidity, bradykinesia, and gait and postural disturbances associated with Parkinson's. For this reason, the majority of patients with Parkinson's disease who require surgery are better treated with interventions in the globus pallidus or subthalamic nucleus, targets that allow improvement in all cardinal features of Parkinson's disease. In contrast, Vim DBS has unequivocal functional benefit in patients with essential tremor, this is likely to remain the major indication of this form of therapy. The mechanism of action of thalamic DBS is not understood and remains a research priority.
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PMID:Vim thalamic stimulation for tremor. 1103 77

During the last decade, it has become increasingly clear that DBS represents a useful adjunct for therapies to control various symptoms of Parkinson's disease. The stimulation sites include the thalamic nucleus ventralis intermedius(Vim), globus pallidus internus(GPi) and subthalamic nucleus (STN). The clinical data of DBS therapy currently available from the literature, together with our own experience, are reviewed. The results of our double blinded evaluation of the effects of GPi and STN stimulation are also summarized. DBS therapy affords the best effect on tremor when the Vim is selected as the stimulation site. DBS therapy is also useful for controlling rigidity when the GPi or STN is stimulated. Improvement of bradykinesia may often be induced by DBS therapy involving the GPi or STN. Dopa-induced dyskinesia can be attenuated effectively by the direct and/or indirect effects of DBS therapy. Two advantages of GPi and STN stimulation were identified in our double blinded evaluation. Firstly, the stimulation can supplement a reduced action of levodopa during the off-period. It thus improves the patient's daily activities through attenuation of the motor fluctuations. Secondly, the stimulation can replace part of the action of levodopa during the on-period. It thus attenuates dopa-induced dyskinesia through a reduced dose of medication. More importantly, the stimulation improves the daily activities in dopa-intolerant patients who are being administered a small dose of levodopa because of unbearable side effects. In addition, GPi stimulation has its own inhibitory effect on dopa-induced dyskinesia.
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PMID:[Deep brain stimulation(DBS) therapy for parkkinson,s disease]. 1106 50

Dopamine depletion induces a series of changes in the basal ganglia motor circuit that underlie the origin of the cardinal features of Parkinson's disease. It has now been established that hyperactivity of the subthalamic nucleus (STN) is an essential feature of the parkinsonian state. This leads to increased excitatory driving onto the globus pallidum internum (GPi) and substantia nigra reticulata (SNr) which, in turn, overinhibits the motor projections to the thalamus and brainstem. The STN and GPi have become the preferred targets for surgery to treat PD. In keeping with the classic pathophysiologic model, physiologic and neuroimaging studies in patients have shown that lesioning or functional blockades (by deep brain stimulation, or DBS) of these nuclei increased cortical activation, in parallel with clinical improvements of bradykinesia. Neuronal recording during surgery has also shown tremor-related activity in both the STN and GPi. However, the pathophysiologic model of the basal ganglia needs further refinement to provide a more detailed explanation of the origin of both tremor and rigidity in Parkinson's disease and to explain the antidyskinetic effect of surgery of the GPi and STN.
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PMID:Pathophysiologic basis of surgery for Parkinson's disease. 1118 78

Chronic high frequency (130 Hz) stimulation (HFS) of the thalamic target Vim, first used in our group in 1987 as a treatment of tremor of various origins, has been used over the last ten years in 137 patients. Since 1993, this method has been extended to two other targets (subthalamic nucleus (STN): 137 patients and the medial pallidum (GPi): 12 patients), based on recent experimental data in rats and monkeys. STN appears to be a target of major interest, able to control the three cardinal symptoms and to allow the decrease or suppression of levodopa treatment, which then also suppresses levodopa induced dyskinesias. The stereotactic technique is based on the determination of the target using ventriculography, MRI and electrophysiology, with both microrecording of single neuron activity and microstimulation inducing therapeutic symptom suppression and side effects. Chronic electrodes are then placed bilaterally at the best physiologically defined location and then connected to implantable stimulators (either 2 Itrel II or the new double channel Kinetra), operated at 130-185 Hz, 60 ms pulse width, 2.5 to 3.5 volts. There was no operative mortality and permanent morbidity was observed in 3 patients. The mechanisms of action of HFS are not fully understood, but are definitely related to high frequency and are probably different depending on the target. Inhibition of cellular activity or of neural network functions could be induced, by jamming of a retroactive loop for tremor, or by shutdown of neurotransmitter release in STN. Mechanisms within an individual target are also probably different for tremor or for other symptom alleviation. All cardinal symptoms are alleviated from tremor to akinesia and rigidity. This strong improvement allows the decrease of the drug dosage to approximately 30% of the preoperative level, which suppresses the levodopa-induced dyskinesias. The off period dystonias are also suppressed as well as freezings and falls. The effects remain stable over more than 5 years and in the same period, the off stimulation-off medication UPDRS remains stable and does not increase at the usual rate The low rate of permanent complications, the minor side effects and their immediate reversibility, the possibility of bilateral implantation in one session and the long-term persistence of symptom relief are strong arguments which support chronic HFS of STN as the method of choice when a surgical procedure is indicated for the treatment of Parkinson's disease and even more when a bilateral procedure is necessary. Recent data show that STN stimulation could be useful in the treatment of dystonia as well as some forms of epilepsy. It is therefore possible that DBS in STN as well as in other targets could become a potent therapeutic tool in the near future for neurological disorders.
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PMID:Deep brain stimulation of the corpus luysi (subthalamic nucleus) and other targets in Parkinson's disease. Extension to new indications such as dystonia and epilepsy. 1169 87

Although technological advances have reduced device-related complications, DBS surgery still carries a significant risk of transient and permanent complications. We report our experience in 86 patients and 149 DBS implants. Patients with Parkinson's disease, essential tremor and dystonia were treated. There were 8 perioperative, 8 postoperative, 9 hardware-related complications and 4 stimulation-induced side effects. Only 5 patients (6%) sustained some persistent neurological sequelae, however, 26 of the 86 patients undergoing 149 DBS implants in this series experienced some untoward event with the procedure. Although there were no fatalities or permanent severe disabilities encountered, it is important to extend the informed consent to include all potential complications.
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PMID:Complications of deep brain stimulation surgery. 1237 60

The present study, the largest in the literature, was performed to assess the effectiveness and safety of unilateral subthalamic nucleus (STN) lesioning for Parkinson's disease (PD). From August 1999 to September 2000, 21 consecutive patients evaluated pre- and postoperatively by a single examiner were operated. Levodopa intake and dyskinesia, Hoehn & Yahr, Schwab & England and UPDRS motor scores were recorded. Stereotactic CT and MRI and the effects of macrostimulation were used to determine STN coordinates. A single radiofrequency lesion was made (60-75 degrees C/60"). Concomitant ipsilateral Vim/VOp lesions were made in 8 patients. Using a new technique, we were able to determine the territory of STN involved by the surgical lesion. The Wilcoxon and Mann-Whitney statistical tests were applied to evaluate the surgical results. All recorded parameters showed stable improvement after a mean follow up of 13.5 months. Recurrence occurred in two patients. Contralateral tremor arrest and decrease of rigidity and bradykinesia should be regarded as STN hallmarks to stimulation. Hyperintense lesions in the early-phase MRI seem to be a poor prognostic factor. Lateral territory lesioning correlates with better results. There was no significant difference between the cohorts with and without a Vim/VOp lesion. Dyskinesias happened in two patients (promptly abolished by a Vim/VOp lesion). Other complications were transient and/or rare. In conclusion, STN lesioning is a safe and very effective procedure to treat PD and probably an underutilized operation for those who can not afford the costs of DBS.
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PMID:Unilateral subthalamic nucleus lesioning: a safe and effective treatment for Parkinson's disease. 1256 84

The mechanism by which chronic, high frequency, electrical deep brain stimulation (HF-DBS) suppresses tremor in Parkinson's disease is unknown. Rest tremor in subjects with Parkinson's disease receiving HF-DBS was recorded continuously throughout switching the deep brain stimulator on (at an effective frequency) and off. These data suggest that the stimulation induces a qualitative change in the dynamics, called a Hopf bifurcation, so that the stable oscillations are destabilized. We hypothesize that the periodic stimulation modifies a parameter affecting the oscillation in a time dependent way and thereby induces a Hopf bifurcation. We explore this hypothesis using a schematic network model of an oscillator interacting with periodic stimulation. The mechanism of time-dependent change of a control parameter in the model captures two aspects of the dynamics observed in the data: (1) a gradual increase in tremor amplitude when the stimulation is switched off and a gradual decrease in tremor amplitude when the stimulation is switched on and (2) a time delay in the onset and offset of the oscillations. This mechanism is consistent with these rest tremor transition data and with the idea that HF-DBS acts via the gradual change of a network property. (c) 2001 American Institute of Physics.
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PMID:Dynamics of Parkinsonian tremor during deep brain stimulation. 1277 15

The effects of unilateral subthalamic nucleus (STN) stimulation contralateral to thalamic stimulation in Parkinson disease (PD) have not been previously reported. We are reporting a patient who developed left arm tremor in 1994, at age 62, as her first PD symptom. She underwent right thalamic DBS surgery in 1999 that resulted in complete resolution of left arm tremor. Her PD symptoms progressed and she developed severe motor fluctuations and disabling dyskinesias. In 2003, she underwent left STN electrode implantation. Left STN stimulation improved contralateral motor scores in the medication OFF state, and allowed for reduced medication doses and less dyskinesia. However, there was no significant improvement in activities of daily living (ADL), motor scores in the medication ON state, gait, or postural stability.
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PMID:Unilateral subthalamic nucleus deep brain stimulation contralateral to thalamic stimulation in Parkinson disease. 1587 88


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