Postural Hand Tremor Research Articles

Amitriptyline enhances the central component of physiological tremor

OBJECTIVESPostural tremor is a regularly encountered side effect of amitriptyline which can be strong enough to cause discontinuation of therapy. The aim was to characterise amitriptyline induced tremor and to...

Quantification of sensory trick impact on tremor amplitude and frequency in 60 patients with head tremor.

Head tremor with an obvious head deviation is the typical clinical picture of tremulous cervical dystonia (TCD), whereas head tremor without any significant head deviation allows for the differential diagnosis of dystonic head tremor (DHT) as well as essential head tremor (EHT). Clinical and polyelectromyographic (poly-EMG) studies have shown a suppression of dystonic muscle activity in patients with TCD performing a maneuver called geste antagonistique. The effect of these trick maneuvers on head tremor has not been investigated in patients with DHT and EHT. We studied the impact of sensory trick maneuvers on head tremor amplitude and frequency clinically by using the tremor subscore of the Tsui scale and by means of computer-based accelerometry in 60 patients with head tremor as their major disorder. Based on clinical data (modified Tsui scale: rating of spontaneous head deviation [rotation + lateroflexion + ante-/retroflexion]), pharmacologic response of tremor (propranolol, primidone, or alcohol), family history (postural hand tremor in first-degree relatives), and poly-EMG findings (reciprocal inhibition in neck muscles during voluntary head rotation), 34 patients were diagnosed as having TCD, 14 were classified as having DHT, and 12 patients were diagnosed as having EHT. Using a clinical rating scale, head tremor amplitudes showed a significant decrease compared with baseline during the performance of sensory trick maneuvers in patients with TCD and DHT, but not in patients with EHT. This clinically observed effect was accompanied by a significant reduction in the mean peak power of the dominant frequency in patients with TCD (decrease by 83%, p = 0.0001) and DHT (decrease by 90%, p = 0.01), but not in patients with EHT (decrease by 6%, p = 0.6). Head tremor frequencies showed no significant changes in relation to the trick maneuvers. We conclude that a significant reduction of head tremor amplitude during a sensory trick maneuver is a useful quantitative criterion to distinguish TCD and DHT from EHT.

The phase of postural hand tremor is not influenced by repetitive photic brain stimulation

Powerful photic stimulation was employed to produce driving of the EEG rhythm recorded from occipital cortex. The resulting quasi-sinusoidal signal was considerably larger than the spontaneous alpha rhythm, and Fourier analysis showed it to be sharply tuned to the frequency of the stimulation which ranged from 7–11 Hz. Physiological postural hand tremor was recorded bilaterally during the period of stimulation. Signal averaging was used to investigate the relationship of the EEG and tremor waveform to the light flashes. The EEG was clearly phasically related to the repetitive stimulus, but the waveform of the tremor was not. We conclude that this external stimulus fails to produce a detectable entrainment of motor output.

A common 3-bp deletion in the DYT1 gene in Russian families with early-onset torsion dystonia.

Hereditary torsion dystonia represent a clinically and genetically heterogeneous group of movement disorders. The most severe and frequent form of hereditary torsion dystonia is early-onset generalized dystonia, DYT1. The DYT1 gene (Ozelius et al., 1997) encodes an ATP-binding protein torsin A. A unique 3-bp deletion (GAG) was found in the heterozygous state in almost all patients with early-onset dystonia from different populations. We observed 39 patients with early-onset generalized torsion dystonia belonging to 22 families from Russia. Seven families were of Ashkenazi Jewish (AJ) ethnic background, and other patients originated from the Slavonic population of Russia. The GAG deletion was identified in 24 affected persons from 15 families (68.2% of the families studied). In all the 7 families of AJ origin the disease was found to be caused by the deletion. In Slavs, the deletion was identified in 8 of 15 families (53%). In two deletion-positive families we observed the co-occurrence of typical early-onset generalized dystonia and atypical phenotypes-either isolated postural hand tremor or stutter.

Clinical expression of essential tremor: effects of gender and age.

Essential tremor (ET) is considered to be a monosymptomatic disorder consisting primarily of postural hand tremor. Nevertheless, clinical expression can vary based on the body region affected by tremor and the coexistence of other neurologic signs, such as tandem gait disturbance. We conducted a two-part study to test the hypothesis that variability in ET clinical expression is influenced by gender and age. In part 1, we examined a large ET clinical database (n = 450), comparing ratings of postural hand and head/voice tremor based on gender. Head/voice tremor was significantly more frequent and more severe among female ET patients; men had more severe postural hand tremor. In part 2, ET patients (n = 40) had significantly more missteps when tandem walking in comparison to age-matched controls. Poor tandem walk in ET cases was associated with more advanced age, but not gender, disease duration, or ratings of postural hand or head/voice tremor. We conclude that gender influences the body region most affected by ET possibly through the effects of the sex chromosomes or hormones. Ataxia (tandem gait difficulty) is common in ET and may be an accentuation of cerebellar dysfunction due to aging.

Characteristics of hand tremor time series.

Tremor is classified into physiological, essential, and parkinsonian tremor by means of clinical criteria. The aim of our work was to extract quantitative features from the measurements of the acceleration of human postural hand tremor. Different mathematical methods were adopted and modified in order to separate these three types of tremor. Best discrimination between physiological and pathological tremors has been achieved by methods distinguishing nonlinear from linear behavior. On the other hand, methods separating different forms of nonlinear behavior have been found to be superior in discriminating parkinsonian and essential tremor. By these methods physiological and pathological tremors can be separated with an error rate below 20% and essential and parkinsonian tremor with an error rate below 10%. This may help to classify tremor time series by objective mathematical criteria and may increase the understanding of the pathophysiological differences underlying these kinds of tremor.

Tremor in Reflex Sympathetic Dystrophy

Postural hand tremor was quantitatively investigated on both sides in 21 patients suffering from unilateral reflex sympathetic dystrophy of the upper extremity. On the affected side, enhanced tremor amplitude, with a mean tremor frequency of 7.2 Hz, was found in 57% of the patients. The appearance of tremor did not correlate to the occurrence of a single clinical symptom of reflex sympathetic dystrophy. On loading with increasing weight, the frequency of this pathological tremor shifted toward lower values, as it is found in physiological tremor. However, the peak frequencies of the electromyogram remained more or less stable. On recovery from this condition, the reflex sympathetic dystrophy tremor disappeared. Acute sympatholytic intervention could normalize reflex sympathetic dystrophy tremor. This would suggest that the sympathetic supply of the affected extremity contributes to the tremor in reflex sympathetic dystrophy. In conclusion, it is suggested that reflex sympathetic dystrophy should be included among the causes of tremor. According to our findings, tremor in reflex sympathetic dystrophy should be regarded as an enhanced physiological tremor.

Orthostatic tremor: An association with essential tremor

Orthostatic tremor is characterized by tremor of the trunk and legs while standing. Rapid frequency has been emphasized as an important criterion for the diagnosis of this tremor. We observed five patients who had the typical findings of orthostatic tremor but had a wide range of frequencies. All five also had postural hand tremor and a family history of essential tremor, suggesting a relationship between orthostatic tremor and essential tremor. This report also emphasizes the association of orthostatic tremor with painful cramps and a relatively consistent improvement with clonazepam.

Motor dysfunction in HIV-infected patients without clinically detectable central-nervous deficit

Motor tests were performed in 50 HIV-infected patients in all stages according to the current CDC classification, but without any clinically evident central nervous system deficit, and the results compared with an age-matched control group. Patients were excluded from the study if there was alcohol or drug abuse, fever and/or opportunistic cerebral infection. The parameters tested were postural tremor of the outstretched hands, most rapid voluntary alternating index finger movements (MRAM) and rise time of most rapid index finger extensions (MRC). Whereas tremor peak frequencies did not differ significantly in the patients and controls, MRAM and rise times of MRCs showed significant slowing in the patient group. Morphologically, the motor test performance of the HIV-infected patients was similar to that of patients with manifest basal ganglia disease (Parkinson's, Huntington's and Wilson's diseases). MRI scans of all patients were normal. It is concluded that in HIV-infected patients there is a very early subclinical central nervous system affection, especially of the basal ganglia, which is detectable with appropriate, quantitative motor function tests. These functional abnormalities precede the structural alterations in the MRI scans.

Neue elektrophysiologische Befunde zur Häufigkeit der Gehirnbeteiligung bei klinisch-neurologisch asymptomatischen HIV-Infizierten

Motor (postural tremor of the outstretched hands, most rapid voluntary alternating index finger movements and rise times of most rapid voluntary isometric index finger extensions) and psychometric tests (multiple choice vocabulary test - form b, syndrome short test, the German version of the standard progressive matrices - Raven, and the psychic and somatic findings according to the AMDP-system) as well as MRI-Scans were analysed in 100 HIV-infected patients of all stages according to the actual CDC-classification, but without any central-nervous or psychic deficit. Patients with drug, alcohol or tranquilizer abuse, opportunistic, cerebral infections or fever were excluded from the study. Tremor-peak-frequencies and reaction times did not show any significant difference to an age- and sex-matched control group; the other motor parameters revealed significant slowing in the patient group and a worsening with the CDC-stages. MRI-scans of all the patients were normal. The psychometric tests did not show significant alterations on a group statistical level, especially not in the depression scales. Morphologically, the motor performances of the HIV-infected patients resembled those of patients with basal ganglia diseases (M. Huntington, M. Wilson, M. Parkinson). Correspondingly, in some cases of clinically dementive HIV-positive patients, MRI-scans showed lesions in the basal ganglia.

Stability of frequency during long-term recordings of hand tremor

During recording of physiological postural hand tremor over a period of 60 min tremor peak frequency (PF) did not change in 14 normal subjects as long as the mechanical conditions were not changed. In contrast, tremor amplitude and synchronization of the corresponding EMG varied considerably. Any alteration in hand mechanics such as changing hand position or adding masses led to changes of PF according to the alteration in mechanical resonant properties. The results show that PF of physiological postural hand tremor is mainly determined by mechanical factors. There is no evidence for a systematic decrease of PF (Stiles et al. 1976) or for the emergence of a formerly described (Lippold 1981) 4–6 Hz tremor component with prolonged maintenance of posture. In the pathological tremor forms of Parkinson's disease or essential tremor PF also remained unchanged during prolonged maintenance of posture.

Frequency/amplitude characteristics of postural tremor of the hands in a population of patients with bilateral essential tremor: implications for the classification and mechanism of essential tremor.

Amplitude/frequency characteristics of postural hand tremor in 59 patients with bilateral essential tremor of various degrees of severity were assessed using accelerometric recordings and spectral analysis. Intra-subject comparisons of tremor characteristics between the more and less affected hands were used to control for variability of tremor due to age factors and intersubject differences in amplitude and frequency. Statistical analysis distinguished three different patient groups. Some patients had low amplitude (less than 0.1-0.015 cm) tremor in the less affected limb (which tended to be 7 Hz or more in frequency in the young) and a larger amplitude tremor in the more affected hand which was 1 Hz or more lower in frequency. Other subjects had either bilaterally small or bilaterally large amplitude tremors of similar frequencies. These findings imply that there is a downwards step in frequency between symptomatic tremors of small and large amplitude. The amplitude and frequency of the small amplitude tremors were unrelated but frequency declined with age. The frequency of the large amplitude tremor was generally determined by amplitude but a wide range of amplitudes were compatible with similar frequencies. The frequency of large amplitude tremor also declined with age. It was concluded that there are two types of essential tremor, the smaller amplitude tremor probably derives from an exaggeration of some or all of the mechanisms of normal physiological tremor whereas the larger amplitude tremor probably arises from a separate "pathological" central nervous mechanism. It is not known if or how one may transform into, or be replaced by, the other during progression of the disease.

Selective adrenergic beta-2-receptor blocking drug, ICI-118.551, is effective in essential tremor

Eighteen patients with essential tremor were treated for 2 days with a non-selective adrenergic beta-blocking drug (dl-propranolol, 80 mg X 3), a beta-2-selective blocker (ICI-118.551, 50 mg X 3) and placebo (X 3) in a randomized double blind cross-over study. Postural hand tremor was recorded with an accelerometer before administration of the drugs and at the end of each treatment period. Compared with placebo, both the beta-blocking drugs caused a statistically significant decrease in tremor intensity and they possessed approximately similar antitremor potency. Subjective benefit was reported by 12 of the 18 patients receiving ICI-118.551, 13 when on propranolol and 3 when on placebo.

Time course of a single oral dose of propranolol in essential tremor.

We studied the effects of a single oral dose (120 mg) of propranolol on essential tremor in 12 patients. Postural hand tremor was recorded by an accelerometer, and its amplitude and frequency determined by spectral analysis. Variable patterns of individual responses gave a mean reduction of tremor amplitude of 50% at 2 hours. Tremor was suppressed as long as 8 hours in some patients. Similar tremor reduction was found on chronic therapy. Even without treatment, tremor amplitude varied from 30 to 50%. A single oral dose of propranolol produces a rapid and sustained reduction of essential tremor, but there are diurnal fluctuations of tremor intensity regardless of treatment.

Mechanical and neural feedback factors in postural hand tremor of normal subjects.

Mechanical and neural feedback factors in postural hand tremor of normal subjects.R N StilesR N StilesPublished Online:01 Jul 1980https://doi.org/10.1152/jn.1980.44.1.40MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByCross-limb dynamics of postural tremor due to limb loading to fatigue: neural overflow but not couplingSteven Morrison, Justin J. Kavanagh, and Karl M. Newell29 July 2019 | Journal of Neurophysiology, Vol. 122, No. 2Characteristics of Rest and Postural Tremors in Parkinson’s Disease: An Analysis of Motor Unit Firing Synchrony and Patterns1 May 2018 | Frontiers in Human Neuroscience, Vol. 12The effects of isometric resistance training on stretch reflex induced tremor in the knee extensor musclesRade Durbaba, Angela Cassidy, Francesco Budini, and Andrea Macaluso15 June 2013 | Journal of Applied Physiology, Vol. 114, No. 12Parallel Neuronal Mechanisms Underlying Physiological Force Tremor in Steady Muscle Contractions of HumansConstantinos N. Christakos, Nikos A. Papadimitriou, and Sophia Erimaki1 January 2006 | Journal of Neurophysiology, Vol. 95, No. 1Augmented visual feedback increases finger tremor during postural pointing30 July 2004 | Experimental Brain Research, Vol. 159, No. 4Damping Actions of the Neuromuscular System With Inertial Loads: Human Flexor Pollicis Longus MuscleDavid C. Lin, and W. Zev Rymer1 March 2001 | Journal of Neurophysiology, Vol. 85, No. 3Physiological tremor in human subjects with X‐linked Kallmann's syndrome and mirror movements5 August 2004 | The Journal of Physiology, Vol. 530, No. 3CROSS-SPECTRAL ANALYSIS OF TREMOR TIME SERIES20 November 2011 | International Journal of Bifurcation and Chaos, Vol. 10, No. 11Coactivation of the antagonist muscle does not covary with steadiness in old adultsRebecca A. Burnett, Douglass H. Laidlaw, and Roger M. Enoka1 July 2000 | Journal of Applied Physiology, Vol. 89, No. 1Damping Actions of the Neuromuscular System With Inertial Loads: Soleus Muscle of the Decerebrate CatDavid C. Lin, and W. Zev Rymer1 February 2000 | Journal of Neurophysiology, Vol. 83, No. 2Load-Independent Contributions From Motor-Unit Synchronization to Human Physiological TremorDavid M. Halliday, Bernard A. Conway, Simon F. Farmer, and Jay R. Rosenberg1 August 1999 | Journal of Neurophysiology, Vol. 82, No. 2Modeling Noisy Time Series: Physiological TremorInternational Journal of Bifurcation and Chaos, Vol. 08, No. 07Central Mechanisms of TremorJournal of Clinical Neurophysiology, Vol. 13, No. 2Does the level of adaptation to a heavy physical effort influence fatigue-induced changes in tremor amplitude?Human Movement Science, Vol. 13, No. 2Knee angle as a determinant of lower leg tremorClinical Biomechanics, Vol. 9, No. 3Effects of strength training-induced fatigue on tremor spectrum in elbow flexionHuman Movement Science, Vol. 13, No. 1Effects of muscle torque and stiffness of spring load on human lower leg tremorHuman Movement Science, Vol. 12, No. 3The muscle activity spectrum: spectral analysis of muscle force as an estimator of overall motor unit activityElectroencephalography and Clinical Neurophysiology, Vol. 63, No. 3Relationship between amplitude of tremor and reflex response of the human jaw-closing systemBrain Research, Vol. 366, No. 1-2Activity of muscle spindles, motor cortex and cerebellar nuclei during action tremorBrain Research, Vol. 323, No. 2Nonlinear damping properties and postural stability of the neuromuscular system More from this issue > Volume 44Issue 1July 1980Pages 40-59 https://doi.org/10.1152/jn.1980.44.1.40PubMed7420138History Published online 1 July 1980 Published in print 1 July 1980 Metrics

Involuntary ankle oscillations from normal subjects.

Spectral analysis of ankle tremor records obtained from normal seated subjects during continuous elevation of the heel for 10-45 min revealed that the root-mean-square (rms) displacement amplitude of the tremor increased from minimum values of about 4 micronm to values as large as 4,000 micronm. Associated with this increase in the displacement amplitude was a systematic decrease in the tremor frequency from values of 7-8 Hz to values of 5-6 Hz. Spectral analysis of demodulated soleus EMG records indicated that the rms value of this EMG (calculated at the tremor frequency) and the rms displacement of the tremor are related by a power function, with the rms value of the EMG increasing over a range of about 4-40 micronV as the tremor displacement increased from about 4 to 4,000 micronm. The negative relation between frequency and rms displacement amplitude values for postural ankle tremor was similar to that found previously for postural hand tremor.