Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TREMOR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMedDate not supplied

[Dysfunction of the upper respiratory airways in patients with essential tremor].

OBJECTIVES: To investigate pulmonary function abnormalities in essential tremor. METHODS: We obtained maximal inspiratory and expiratory flow-volume curves in 41 unselected patients with essential tremor (14 males, 27 females, age 61.7 +/- 2.14 years). Severity of essential tremor was evaluated using the Fahn, Tolosa and Marin clinical scale. RESULTS: Sixteen patients (39.0%) had flow oscillations on the flow-volume curves (8 only during inspiration, 7 during inspiration and expiration, and 1 with flow oscillations during inspiration and obstructive pattern). The duration and severity of the essential tremor did not influence the pattern of the curve, but abnormal curves were more frequent in patients with voice tremor. Although there were a number of significant correlations between essential tremor scales and spirographic parameters, they were of very low range. Four patients (9.8%) fulfilled criteria for physiological upper airway obstruction: 2 had smooth flow-volume loop contour and 2 had flow oscillations in inspiration and expiration. CONCLUSION: Abnormalities in flow-volume loop contour are a usual finding in essential tremor. This probably reflects involvement of the upper airway musculature, that in some patients can produce clinical upper airway obstruction.

Female↗
PubMed1993

[Tremors].

Tremor can present a diagnostic problem in family practise. Systematic analysis of this symptom allows rapid classification of the problem without use of rigid definitions. Unilateral or very asymmetric tremor that disappears at the onset of a movement is for example a typical sign for parkinsonism without analysis and differentiation between tremor at rest or position-dependent tremor. Also one may assume, that a symmetric tremor that aggravates during standing or movement in most cases is essential and not of cerebellar origin. Different forms of tremor and their therapies and main tremor types are presented graphically.

Adult↗
PubMed1995

[A case of portal-systemic encephalopathy with slowly progressive, non-flapping tremor].

A 52-year-old man has slowly developed a non-flapping tremor during 30 years. He also had suffered from poor concentration for two years. He had, however, no history of episodic disturbance of consciousness. He had no other neurological symptoms except for tremor and hyperreflexia. The tremor was postural and intentional, and extremely increased at the end point. The factor of intentional tremor and hyperkinesia volitionnelle seems to be present in the tremor. Laboratory examination disclosed a hyperammonemia, reduction in Fisher ratio, and poor excretion of ICG. Selective abdominal angiography visualized a large shunt vessel between the left gastric vein and the left renal vein. The normal liver scintigram with 99mTc excluded the dysfunction of liver, and we conclude that the shunt vessel might be congenital. Tremor markedly improved after normalizing blood ammonia level by resection of the shunt vessel. The present case suggests that tremor, even without episodic disturbance of consciousness, could be based on the portal-systemic encephalopathy.

Ammonia↗
PubMed1997

Generalized tremors in dogs: 24 cases (1984-1995).

OBJECTIVE: To characterize clinical features, diagnostic evaluation, and treatment outcome for dogs with generalized tremors. DESIGN: Retrospective case series. ANIMALS: 12 white purebred and 12 nonwhite mixed-breed and purebred dogs. PROCEDURE: Medical records of dogs examined for tremors between January 1984 and July 1995 were reviewed. History, signalment, abnormalities on physical and neurologic examinations, results of diagnostic testing, and diagnosis were recorded for each dog. Results were divided into the following 3 categories on the basis of the cause of the tremors: inflammatory, noninflammatory, and idiopathic. Cause was determined by results of CSF analyses or a history of toxin exposure. RESULTS: The only noninflammatory cause of generalized tremors identified in these dogs was mycotoxin ingestion. Steroid-responsive tremor syndrome had developed in 22 of 24 dogs, half of which had abnormal results of CSF analyses. Most dogs were young adults between 1 and 5 years old. More than half of the dogs were nonwhite mixed-breeds and all weighed < 15 kg (33 lb). Eighty percent of the dogs responded to immunosuppressive treatment within 3 days. CLINICAL IMPLICATIONS: Inflammatory and noninflammatory causes for generalized tremors in dogs result in similar clinical signs, so a logical diagnostic and treatment approach is needed. Steroid-responsive tremor syndrome should be considered in small- to medium-breed, young adult dogs, regardless of coat color. A rapid and complete response to immunosuppressive treatment is expected.

Administration, Oral↗
PubMed1997

An investigation of stretch reflex in physiological tremor.

This paper describes a theoretical consideration on muscle stretch reflex in physiological tremor (abbreviated as tremor). In making a model, the function of rostro-caudal homonymous motoneurone pool as well as the interaction between spinal cord mechanism and supraspinal system is investigated. The known physiology of the neuromuscular oscillations is used to evaluate the responses of a set of differential equation that represents lumped system dynamics underlying the stretch reflex process of tremor. According to the model, the stretch reflex along with the mechanics of limb is behaving as a filter. With sharp resonant peaks and without the need of any external inputs, the filter selects oscillators and sustains tremulous movement. These reflex features, especially the findings of an existence of two sharp resonant centers, are particular valuable in an explanation of the two spectral peaks observed in tremor. It is demonstrated that (1) the two peaks of tremor, which vibrate at 10 Hz and 20 Hz, largely depend on the coupling lambda between spinal and supraspinal system, i.e., lambda leads to "spontaneous symmetry breaking" producing a peak doubling; (2) the two peaks are attributable to two decoupled states found in our model. The pea with 10 Hz is attributed to the state Z+ (t) describing an average state of spinal+supraspinal system, while the one with 20 Hz denotes the state Z-(t) which presents a relative movement of spinal and supraspinal system. With regarding to the nature of tremor under various conditions such as loading, fatigue, and pseudo-gravity, this paper discusses the possible connections of lambda to these experimental environments. Also, this paper argues that representation of stretch reflex by the decoupled states is more essential than other traditional representations used in approaching to tremor phenomena.

Animals↗
PubMed1994

Tremors in Parkinson's disease: symptom analysis and rating.

The object of the present study was to evaluate the hand tremor occurring under various conditions in 81 patients with Parkinson's disease (PD) and to statistically analyze their relation to clinical rating items. We found that resting and action tremor have to be separated, whereas postural tremor can be related to either one of them. Resting tremor does not correlate with disability items or performance items except for an item rating social handicaps. Action tremor shows some influence on performance items. Current rating scales of PD represent a valid measure of resting tremor but are less valid for the measurement of action tremor.

Adult↗
PubMed1997

[Electromyographic characteristics of postanesthetic tremor].

Postanesthetic tremor is a frequent complication during recovery from surgery. Its etiopathogenesis is poorly understood and its electromyographic characteristics have scarcely been studies. We report the electromyographic characteristics of three normothermic patients with postanesthetic tremor. Electromyography revealed tremor to be consistent with that recorded for patients with exacerbated physiological tremor. None of the three patients had electromyographic signs typical of hypothermic patients with tremor. We conclude that the electromyographic signs of postanesthetic tremor should be studied further and consider it noteworthy that the recordings we made could be attributable to high levels of circulating catecholamines, leading to exacerbation of physiologic tremor manifested in the form of postanesthetic shivering.

Adult↗
PubMed1998

['Rubral' tremor after vascular thalamic lesions].

INTRODUCTION: The appearance of tremor after thalamic lesions is well-known but infrequent. Amongst the semiological varieties of thalamic tremors, a particularly uncommon type--which is extremely incapacitating owing to its great amplitude, appearance during action and poor therapeutic response--is the so-called rubric or mesencephalic tremor. CLINICAL CASES: We present four cases, of tremor with the semiological characteristics of rubric tremors after thalamic lesions of ischaemic or haemorrhagic origin. We review the relevant literature. DISCUSSION: The rubric tremor has been said to have its physiopathological origin in a lesion of the nigro-striate via and the efferent cerebellar vias at some point of the mesencephalic or subthalamic path, often without direct involvement of the red nucleus. CONCLUSIONS: The presentation of this type of tremor due to lesions which do not effect the red nucleus and the mesencephalum show the unsuitability of the name.

Aged↗
PubMed1984

Activity of muscle spindles, motor cortex and cerebellar nuclei during action tremor.

Repeated electrode penetration of the dentate and interpositus nuclei in a rhesus monkey transformed an 11-13 Hz physiologic tremor into a much larger action tremor at 5-7 Hz. This tremor was associated with muscle spindle spike train modulation and reflexly evoked tremor modulation of interpositus and motor cortex neurons as well as electromyogram (EMG). No tremor modulation was observed in spike trains recorded from dentate. The timing relationships of the spindle, EMG, and interpositus tremor discharges suggest that the interpositus plays a direct role in tremor suppression. Dentate, by contrast, may function indirectly by setting optimal transcortical long loop reflex dynamics concerned with intended voluntary movement.

Animals↗
PubMed2006

Low-frequency earthquakes in Shikoku, Japan, and their relationship to episodic tremor and slip.

Non-volcanic seismic tremor was discovered in the Nankai trough subduction zone in southwest Japan and subsequently identified in the Cascadia subduction zone. In both locations, tremor is observed to coincide temporally with large, slow slip events on the plate interface downdip of the seismogenic zone. The relationship between tremor and aseismic slip remains uncertain, however, largely owing to difficulty in constraining the source depth of tremor. In southwest Japan, a high quality borehole seismic network allows identification of coherent S-wave (and sometimes P-wave) arrivals within the tremor, whose sources are classified as low-frequency earthquakes. As low-frequency earthquakes comprise at least a portion of tremor, understanding their mechanism is critical to understanding tremor as a whole. Here, we provide strong evidence that these earthquakes occur on the plate interface, coincident with the inferred zone of slow slip. The locations and characteristics of these events suggest that they are generated by shear slip during otherwise aseismic transients, rather than by fluid flow. High pore-fluid pressure in the immediate vicinity, as implied by our estimates of seismic P- and S-wave speeds, may act to promote this transient mode of failure. Low-frequency earthquakes could potentially contribute to seismic hazard forecasting by providing a new means to monitor slow slip at depth.

Journal Article↗
PubMed1980

Physiological tremor enhanced by manoeuvres affecting the segmental stretch reflex.

In view of recent evidence that physiological tremor can be enhanced by positive feedback via the segmental stretch reflex, several manoeuvres and procedures were employed to enhance the finger and hand tremor of healthy subjects--the purpose being to determine if tremorogenic effects, at least in part, are due to increase efficacy of the stretch reflex servo. Mechanical events during tremor (and during voluntary or electrically induced muscle twitches) were recorded together with EMG activity from wrist and finger flexor muscles and discharges from primary spindle endings in these muscles. Physiological tremor can be enhanced not only by manoeuvres which increase the gain of segmental stretch reflexes (Jendrassik manoeuvre) but also by manoeuvres which increase the contrast in spindle firing during stretch versus shortening phases of tremor, thus enhancing reflex modulation. Effects of the latter type can be achieved by procedures which alter mechanical twitch properties of extrafusal fibres (isoproterenol infusions and fatigue) and by procedures which involve application of spindle stimuli acting preferentially during stretch phases of tremor movements (muscle vibrations). Physiological tremor, which can be temporarily enhanced by an externally applied muscle perturbation, also becomes accentuated by those small "pseudo-myoclonic" jerks which occur in all normal subjects attempting to perform slow, smooth movements.

Fatigue↗
PubMed2003

Oral anticoagulation for ECG tremor artefact simulating atrial fibrillation.

That tremor simulates atrial fibrillation and causes oral anticoagulation has not been reported. In a 69-year-old patient with diabetes, arterial hypertension and recurrent strokes, hand tremor developed since 1998. In September 2000 atrial fibrillation was diagnosed upon a routine and 24-hour ambulatory ECG. Because of the additional risk factors for stroke/embolism, phenprocoumon was begun. The diagnosis was changed to paroxysmal AF upon the following ECGs, showing sinus rhythm. Not earlier than 1 year after establishing the diagnosis,"atrial fibrillation" was identified as being due to a tremor artefact. Phenprocoumon was discontinued. Neurological investigations revealed Parkinson's disease as the cause of the tremor. Three weeks after initiation of pramipexol, the tremor artefact was no longer visible on ECG. Misinterpreting an ECG-artefact due to Parkinsons's tremor as atrial fibrillation may be followed by unnecessary diagnostic and therapeutic procedures, including long-term oral anticoagulation. Upon adequate treatment of Parkinson's disease, the tremor artefact immediately disappears from the ECG.

Aged↗
PubMed2003

Accelerometry to distinguish psychogenic from essential or parkinsonian tremor.

The authors measured postural wrist tremor with accelerometry in patients with psychogenic (n = 6), essential (n = 11), and parkinsonian (n = 12) tremor. Tremor was measured in one hand, while the other hand either rested or tapped to an auditory stimulus at 3 and 4 or 5 Hz. Psychogenic tremors showed larger tremor frequency changes and higher intraindividual variability while tapping. Accelerometry may differentiate psychogenic from essential and parkinsonian tremor.

Acceleration↗
PubMed2004

Tremor cells in the human thalamus: differences among neurological disorders.

OBJECT: Thalamic neurons firing at frequencies synchronous with tremor are thought to play a critical role in the generation and maintenance of tremor. The authors studied the incidence and locations of neurons with tremor-related activity (TRA) in the thalamus of patients with varied pathological conditions-including Parkinson disease (PD), essential tremor (ET), multiple sclerosis (MS), and cerebellar disorders--to determine whether known differences in the effectiveness of thalamic stereotactic procedures for these tremors could be correlated to differences in the incidence or locations of TRA cells. METHODS: Seventy-five operations were performed in 61 patients during which 686 TRA cells were recorded from 440 microelectrode trajectories in the thalamus. The locations of the TRA cells in relation to electrophysiologically defined thalamic nuclei and the commissural coordinates were compared among patient groups. The authors found that TRA cells are present in patients with each of these disorders and that these cells populate several nuclei in the ventral lateral tier of the thalamus. There were no large differences in the locations of TRA cells among the different diagnostic classes, although there was a difference in the incidence of TRA cells in patients with PD, who had greater than 3.8 times more cells per thalamic trajectory than patients with ET and approximately five times more cells than patients with MS or cerebellar disorders. CONCLUSIONS: There was an increased incidence of TRA in the thalamus of patients with PD. The location of thalamic TRA cells in patients with basal ganglia and other tremor disorders was similar.

Adult↗
PubMed2000

Diagnosis and management of tremor.

Tremor is the most common involuntary movement disorder. It is differentiated from other involuntary movement disorders, such as chorea, athetosis, ballismus, tics, and myoclonus, by its repetitive, stereotyped, movements of a regular amplitude and frequency. Tremor can be defined as an involuntary, rhythmic, periodic, mechanical oscillation of a body part. Since small-amplitude tremors may not be visible to the naked eye and may only be detectable by sensitive recording devices, amplitude of the tremor is therefore not critical to the definition. Accurate diagnosis of tremor is important because appropriate treatment depends on the accuracy of the clinical diagnosis. This article reviews the classification and management of tremor.

Humans↗
PubMed1984

Metoprolol compared with propranolol in the treatment of essential tremor.

We analyzed effects of metoprolol tartrate and propranolol hydrochloride on 23 patients with essential tremor. Tremor was assessed by patient self-evaluation, clinical scoring, and tremorgrams. Ten of 20 patients had tremor reduction with propranolol. Metoprolol decreased tremor in 13 of 23 patients, including three patients with asthma in whom propranolol had caused respiratory distress. Adverse reactions were infrequent. Individual patients either responded to both propranolol and metoprolol or to neither drug. Patient age, duration of tremor, tremor frequency, family history, or response to intravenous ethyl alcohol did not distinguish responders from nonresponders.

Adult↗
PubMed1986

Dose-response relationship of propranolol in the treatment of essential tremor.

The effect of doses of propranolol hydrochloride, 80 to 800 mg/day, was investigated in 15 patients with essential tremor. The dose was increased by 80 mg weekly. Tremor was recorded by an accelerometer and its amplitude and frequency was determined by spectral analysis. Serum propranolol level was measured by radioreceptor assay. Tremor control varied greatly from complete suppression at 80 mg/day to no reduction at 800 mg/day. Mean serum propranolol levels increased with increasing dosage, but they did not correlate with tremor suppression. Five patients did not tolerate doses higher than 640 mg/day. Maximum tremor suppression occurred within a dose range between 160 and 320 mg/day. Higher doses did not cause additional tremor reduction.

Dose-Response Relationship, Drug↗
PubMed1992

Peripheral mechanical loading and the mechanism of the tremor of chronic alcoholism.

The tremor of chronic alcoholism, although clinically similar to essential tremor, has been considered a distinct syndrome. Its underlying mechanism was analyzed in five patients (none in the acute stages of alcohol withdrawal) hospitalized in an alcohol detoxification program. All five patients performed tracking tasks in which they pursued a linearly moving "target" light with a response light that they controlled by flexion-extension activity of the wrist. Stationary and dynamic targets were used with both isometric and unconstrained wrist mechanical interfaces. Frequency, torque, and displacement tremor characteristics were examined under varying inertial loading or isometric voluntary torque conditions. Two simultaneous tremor components were present in all patients: a prominent 4- to 7-Hz low-frequency peak and a smaller-amplitude 9.4- to 9.6-Hz high-frequency peak. As the inertia of the hand was augmented during unconstrained tasks, the low-frequency peak decreased, while the high-frequency peak was unaffected. As required voluntary effort was increased during isometric testing, the amplitude of the low-frequency peak increased. These findings suggest that the low-frequency peak represents the significant pathologic component of the tremor of chronic alcoholism and that it has a biomechanical reflex mechanism similar to that of the lower-amplitude normal physiologic tremor.

Adult↗