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

A special movement therapy, called coordination dynamics therapy, has been reported to have the potential to improve central nervous system (CNS) functioning in Parkinson's disease patients. Electromyography using surface electrodes (sEMG) showed that the rhythmic muscle activity leading to Parkinsonian tremor was generated in the patients by the impairment of two kinds of inhibition. First, some premotor spinal oscillators organized themselves in the CNS neuronal networks without strong adequate input and second, the oscillators synchronized their firing to give rise to rhythmic muscle activity and tremor. In this paper it will be shown that highly coordinated arm and leg movements, generated when exercising on a special coordination dynamics therapy device, can reduce Parkinsonian tremor in amplitude and frequency and improve CNS functioning in the short-term memory. sEMG measurements showed upon exercising on the special coordination dynamics therapy device that the motor program improved in the short-term memory and tremor muscle activity became coordinated with the volitional motor program and reduced in size and frequency. Higher load exercising seemed to better reduce tremor muscle activity, probably because the physiologic CNS organization was more integrative then and could 'bind' stronger simultaneous pathologic tremor activity. Moreover, the rhythmic synchronized motor unit firing in different arm and leg muscles was synchronized or coordinated and changed in frequency and amplitude. It is concluded that the integrative re-organization mechanism to reduce Parkinsonian tremor is the phase and frequency coordination between neuron firing of the physiologic neuronal network state, generated by the highly coordinated arm and leg movements, and the simultaneous pathologic tremor network state, generated by the uninhibited neurons, firing synchronized oscillatory.
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PMID:Integrative re-organization mechanism for reducing tremor in Parkinson's disease patients. 1643 48

It is generally accepted that patients with a tremor-dominant type of idiopathic Parkinson's disease progress more slowly than the ones with the rigid-akinetic type. On the other hand successful treatment of Parkinsonian tremor is a challenge. German neurologists use anticholinergics, budipine, beta-blockers, clozapine, dopaminergic substances and for most severe cases deep brain stimulation. Budipine is an enigma because its main mode of action is still unknown, although it is mostly listed under glutamate antagonists. There is however no other anti-Parkinsonian drug available with such a broad spectrum of action as shown for budipine. Budipine has been studied in open and double-blind studies as monotherapy and adjunct therapy. In both instances the drug showed beneficial effects to the patients. It may well be that the non-dopaminergic mode of action of budipine is helpful even for patients who are on stable medication. When 3 years ago reports on budipine-induced prolongation of the QT interval in the ECG emerged larger trials were stopped and nowadays there are strict rules on how to use budipine. Nonetheless, budipine in our hands is a most useful and safe drug to treat tremor and other main symptoms of Parkinson's disease.
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PMID:Budipine in Parkinson's tremor. 1678 59

Low frequency rest tremor is one of the cardinal signs of Parkinson's disease and some of its animal models. Current physiological studies and models of the basal ganglia differ as to which aspects of neuronal activity are crucial to the pathophysiology of Parkinson's disease. There is evidence that neural oscillations and synchronization play a central role in the generation of the disease. However, parkinsonian tremor is not strictly correlated with the synchronous oscillations in the basal ganglia networks. Rather, abnormal basal ganglia output enforces abnormal thalamo-cortical processing leading to akinesia, the main negative symptom of Parkinson's disease. Parkinsonian tremor has probably evolved as a downstream compensatory mechanism.
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PMID:Basal ganglia oscillations and pathophysiology of movement disorders. 1708 15

Tremor is one of the most frequent neurological signs. The correct clinical classification is mainly clinical. The most frequent primarily neurological tremor is essential tremor (prevalence 2 to 5%). It presents in most cases as a more or less symmetrical postural and kinetic tremor. In about 60% of cases an autosomal-dominant inheritance is found. Tremor may manifest not only in the hands but also in the head and voice. In about 60 to 70% of the patients alcohol may improve the tremor. Parkinsonian tremor is normally a tremor at rest and it starts asymmetrically. The legs and the face are frequently involved. Cerebellar tremor is intentional. Orthostatic tremor, which has a high frequency, mainly manifests in the legs and gives rise to postural instability. Dystonic tremor is an action tremor of the affected region of the body. Drug therapy, which is purely symptomatic, mostly depends on clinical manifestation. Postural and action tremors respond to non selective betablockers (propranolol), primidone, some antiepileptics (gabapentin, toparimate) and benzodiazepines. Classical rest tremors are improved by dopaminergic substances (levodopa, dopamine agonists) or anticholinergics. Dystonic tremor may successfully be treated by injections of botulinum toxin. Orthostatic tremor responds to gabapentin or benzodiazepines in some of the patients. In severely handicapped patients with refractory tremors the implantation of thalamic stimulation electrodes may be considered. This treatment may be very successful, however, its inherent risks have to be taken into account.
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PMID:[Tremor]. 1722 23

Changes in shoulder position influence motor cortical outflow to Abductor Digiti Minimi (ADM) muscle in healthy humans. We examined whether these changes may affect finger tremor of central origin. Subjects had their shoulder positioned in two different configurations: 30 degrees horizontal adduction (ANT) and 30 degrees horizontal abduction (POST) with respect to neutral position at 0 degrees in the horizontal plane. In healthy subjects, patients with Parkinsonian tremor (PT) and essential tremor (ET), transcranial magnetic stimulation (TMS) of the motor cortex was performed under resting and active conditions in ANT and POST. PT, ET and physiological tremor (PhT) were studied by accelerometric recordings from the little finger and by EMG activity from ADM and Extensor Carpi Radialis (ECR) in ANT and POST. In healthy and ET subjects, ADM motor evoked responses (MEPs) to TMS were smaller under resting, but larger under active conditions in POST. In PT patients, MEPs showed no difference at rest in ANT but were lower during ADM activation in POST. PT decreased, whereas ET increased in POST. These changes were paralleled by a decrease in PT EMG power and an increase in ET EMG power in POST. In PhT, there was no difference in tremor amplitude between ANT and POST. PT decrease and ET increase in POST parallel the changes in motor cortical outflow to ADM induced by modification of shoulder position under active conditions. This may be evidence for altered premotor-motor interaction at cortical level in PT, and for a role of the motor cortex in generating ET.
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PMID:Effects of posture-related changes in motor cortical output on central oscillatory activity of pathological origin in humans. 1859 45

Tremor is one of the most frequent neurological signs; the diagnosis is mainly clinical. The most frequent tremor is essential tremor, which manifests itself as a postural and kinetic tremor. Tremor may occur not only in the hands, but also in the head and voice. Parkinsonian tremor is a tremor at rest; the legs and face are frequently involved. Orthostatic tremor mainly manifests itself in the legs and gives rise to postural instability. Dystonic tremor is an action tremor of the affected region of the body. Drug therapy mostly depends on the clinical manifestation. Postural and action tremors respond to beta blockers, primidone, some antiepileptics and benzodiazepines. Classical rest tremors are improved by dopaminergic substances or anticholinergics. Dystonic tremor may be successfully treated by injecting botulinum toxin. Orthostatic tremor responds to gabapentin or benzodiazepines in some patients. In patients with severely disability, implantation of thalamic stimulation electrodes may be considered.
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PMID:[Tremor. Differential diagnosis and treatment]. 1861 93

Tremor in Parkinson's disease (PD) is generated by an oscillatory neuronal network consisting of cortex, basal ganglia and thalamus. The subthalamic nucleus (STN) which is part of the basal ganglia is of particular interest, since deep brain stimulation of the STN is an effective treatment for PD including Parkinsonian tremor. It is controversial if and how the STN contributes to tremor generation. In this study, we analyze neuronal STN activity in seven patients with Parkinsonian rest tremor who underwent stereotactic surgery for deep brain stimulation. Surface EMG was recorded from the wrist flexors and extensors. Simultaneously, neuronal spike activity was registered in different depths of the STN using an array of five microelectrodes. After spike-sorting, spectral coherence was analyzed between spike activity of STN neurons and tremor activity. Significant coherence at the tremor frequency was detected between EMG and neuronal STN activity in 76 out of 145 neurons (52.4%). In contrast, coherence in the beta band occurred only in 10 out of 145 neurons (6.9%). Tremor-coherent STN activity was widely distributed over the STN being more frequent in its dorsal parts (70.8-88.9%) than in its ventral parts (25.0-48.0%). Our results suggest that synchronous neuronal STN activity at the tremor frequency contributes to the pathogenesis of Parkinsonian tremor. The wide-spread spatial distribution of tremor-coherent spike activity argues for the recruitment of an extended network of subthalamic neurons for tremor generation.
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PMID:Tremor-correlated neuronal activity in the subthalamic nucleus of Parkinsonian patients. 1863 49

The cortical sources of both the basic and first 'harmonic' frequency of Parkinsonian tremor are addressed in this paper. The power and coherence was estimated using the multitaper method for EEG and EMG data from 6 Parkinsonian patients with a classical rest tremor. The Dynamic Imaging of Coherent Sources (DICS) was used to find the coherent sources in the brain. Before hand this method was validated for the application to the EEG by showing in 3 normal subjects that rhythmic stimuli (1-5Hz) to the median nerve leads to almost identical coherent sources for the basic and first harmonic frequency in the contralateral sensorimotor cortex which is the biologically plausible result. In all the Parkinson patients the corticomuscular coherence was also present in the basic and the first harmonic frequency of the tremor. However, the source for the basic frequency was close to the frontal midline and the first harmonic frequency was in the region of premotor and sensory motor cortex on the contralateral side for all the patients. Thus the generation of these two oscillations involves different cortical areas and possibly follows different pathways to the periphery.
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PMID:Imaging coherent sources of tremor related EEG activity in patients with Parkinson's disease. 1916 69

Loss of dopaminergic neurons from the substantia nigra characterizes the classical pathology of Parkinson's disease, but persistent activation of N-methyl-D-aspartate receptors is also a major component. During difficult airway management in a patient with advanced Parkinson's disease, the use of low-dose (20 mg) i.v. ketamine resulted in complete abolition of severe tremor and dysarthria. This led to the current case report in which low-dose ketamine was used for preoperative sedation and dyskinesia attenuation. Prior research and our experience would suggest that low-dose ketamine, titrated to effect, may provide optimal patient comfort and perioperative control of Parkinsonian tremor.
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PMID:The utility of ketamine for the preoperative management of a patient with Parkinson's disease. 1922 12

While the majority of tremor-afflicted Parkinso-nian (PD) patients suffer from rest tremors, which is not considered highly disabling, a portion of these PD patients also demonstrate action tremors that interfere with their daily lives. Two main considerations in designing an orthosis that aims at suppressing the tremor, are the frequency bands of the tremor and the joints tremor affects. Nine subjects, which included six healthy people, two PD patients with typical tremor afflictions, and a PD patient with severe tremor of not only in her fingers and wrist, but also in her elbow, participated in this study. The highly afflicted patient displayed the need for tremor suppression in action as well as when in rest. The study focuses on uncommon elbow tremors and demonstrates that, for typically afflicted patients, tremor amplitudes are comparable to healthy subjects, but the frequency distribution of the tremors are different at high levels of elbow torque. For the highly afflicted patient, both tremor amplitude and its frequency distribution are different at all levels of elbow torque. The study further investigates the tremors in two bands of frequency on both hands of the highly troubled patient before, and after medication. The two bands are those of classical Parkinsonian tremor (4-6 Hz) and physiological (or enhanced physiological) tremor (8-12 Hz). Power spectrum and tremor amplitude comparisons reveal that, for part of tremulous PD patients, both tremors coexist and, depending on the level of affliction, the designed orthosis needs to suppress tremors in both bands, even at more proximal joints, such as the elbow.
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PMID:Tremor suppression orthoses for parkinson's patients: a frequency range perspective. 1996 11


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