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  1. Somatosensory temporal discrimination in essential tremor and isolated head and voice tremors.

    Science.gov (United States)

    Conte, Antonella; Ferrazzano, Gina; Manzo, Nicoletta; Leodori, Giorgio; Fabbrini, Giovanni; Fasano, Alfonso; Tinazzi, Michele; Berardelli, Alfredo

    2015-05-01

    The aim of this study was to investigate the somatosensory temporal discrimination threshold in patients with essential tremor (sporadic and familial) and to evaluate whether somatosensory temporal discrimination threshold values differ depending on the body parts involved by tremor. We also investigated the somatosensory temporal discrimination in patients with isolated voice tremor. We enrolled 61 patients with tremor: 48 patients with essential tremor (31 patients with upper limb tremor alone, nine patients with head tremor alone, and eight patients with upper limb plus head tremor; 22 patients with familial vs. 26 sporadic essential tremor), 13 patients with isolated voice tremor, and 45 healthy subjects. Somatosensory temporal discrimination threshold values were normal in patients with familial essential tremor, whereas they were higher in patients with sporadic essential tremor. When we classified patients according to tremor distribution, somatosensory temporal discrimination threshold values were normal in patients with upper limb tremor and abnormal only in patients with isolated head tremor. Temporal discrimination threshold values were also abnormal in patients with isolated voice tremor. Somatosensory temporal discrimination processing is normal in patients with familial as well as in patients with sporadic essential tremor involving the upper limbs. By contrast, somatosensory temporal discrimination is altered in patients with isolated head tremor and voice tremor. This study with somatosensory temporal discrimination suggests that isolated head and voice tremors might possibly be considered as separate clinical entities from essential tremor. © 2015 International Parkinson and Movement Disorder Society.

  2. Tremor

    Science.gov (United States)

    Tremors are unintentional trembling or shaking movements in one or more parts of your body. Most tremors occur in the hands. You can also have arm, head, face, vocal cord, trunk, and leg tremors. Tremors are most common in middle-aged and ...

  3. Defining Dystonic Tremor

    OpenAIRE

    Elble, Rodger J

    2013-01-01

    A strong association between dystonia and tremor has been known for more than a century. Two forms of tremor in dystonia are currently recognized: 1) dystonic tremor, which is tremor produced by dystonic muscle contraction and 2) tremor associated with dystonia, which is tremor in a body part that is not dystonic, but there is dystonia elsewhere. Both forms of tremor in dystonia frequently resemble essential tremor or another pure tremor syndrome (e.g., isolated head and voice tremors and tas...

  4. Early Head Tremor in Essential Tremor: A Case Series and Commentary

    OpenAIRE

    Louis, Elan D.; Badejo, Funmi M.; Cristal, Ashley D.; Meyers, James; Hernandez, Nora; Chen, Karen P.; Naranjo, Kelly V.; Park, Jemin; Clark, Lorraine N.

    2017-01-01

    Background Classically, the onset of head tremor in essential tremor (ET) patients follows that of hand tremor, such that there is a somatotopic spread of involved areas. Here we present a series of seven self?reportedly ?unaffected? relatives of ET cases. These seven were clinically asymptomatic and had normal levels of arm tremor on examination, yet each evidenced a transient head wobble on examination. We estimate the prevalence of this phenotype within the two studies from which cases wer...

  5. Early Head Tremor in Essential Tremor: A Case Series and Commentary.

    Science.gov (United States)

    Louis, Elan D; Badejo, Funmi M; Cristal, Ashley D; Meyers, James; Hernandez, Nora; Chen, Karen P; Naranjo, Kelly V; Park, Jemin; Clark, Lorraine N

    2017-01-01

    Classically, the onset of head tremor in essential tremor (ET) patients follows that of hand tremor, such that there is a somatotopic spread of involved areas. Here we present a series of seven self-reportedly "unaffected" relatives of ET cases. These seven were clinically asymptomatic and had normal levels of arm tremor on examination, yet each evidenced a transient head wobble on examination. We estimate the prevalence of this phenotype within the two studies from which cases were ascertained. ET cases and their self-reportedly affected and unaffected relatives, enrolled in two family studies, underwent a medical history and videotaped neurological examination. In seven self-reportedly "unaffected" relatives, a transient and subtle head wobble was seen, always during sustained phonation, speech, or reading aloud. Total tremor score (a measure of arm tremor) ranged from 5 to 12 (i.e., mild tremor within the range of normal). The prevalence of this phenotype of early head tremor was 3.7% in one study and 23.1% in the other. We present a series of seven individuals who had early head tremor in an evolving transition state from normal to ET. These cases raise a number of broad clinical, phenotypic, and pathophysiological issues about ET.

  6. Idiopathic head tremor in English bulldogs.

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    Guevar, Julien; De Decker, Steven; Van Ham, Luc M L; Fischer, Andrea; Volk, Holger A

    2014-02-01

    Idiopathic head tremor (IHT) syndrome is a recognized but poorly characterized movement disorder in English bulldogs (EBs). The data analyzed were collected via a detailed online questionnaire and video recordings. Thirty-eight percent of the population demonstrated IHT. The first presentation was early in life. There was no sex or neutered status predisposition. The condition disappeared with time in 50% of the cases. The direction of the head movement was vertical or horizontal. The number of episodes per day and the duration of the episodes were greatly variable. The majority of episodes occurred at rest. Most of the episodes were unpredictable. And there was no alteration of the mental status for most dogs during the episodes. Stress has been reported as a suspected trigger factor. IHT in EBs can be considered an idiopathic paroxysmal movement disorder. © 2013 Movement Disorder Society.

  7. An inherited episodic head tremor syndrome in Doberman pinscher dogs.

    Science.gov (United States)

    Wolf, Martina; Bruehschwein, Andreas; Sauter-Louis, Carola; Sewell, Adrian C; Fischer, Andrea

    2011-11-01

    Episodic head tremor anecdotally occurs in the Doberman pinscher dog breed, but it is not described in sufficient detail in the literature. We evaluated 87 Doberman pinschers affected with episodic head tremor and appropriate controls. The data analyzed were collected through detailed questionnaires, elaborate telephone interviews, and video recordings. Affected dogs underwent clinical, neurological, and laboratory examination, and a detailed diagnostic workup was conducted in 5 affected dogs. Pedigrees of affected dogs were collected and reviewed. The affected dogs expressed individual phenotypes of either horizontal or vertical head movements, but rarely did a dog exhibit head movements in both directions. There was considerable variation in duration (10 seconds to 3 hours; median: 3 minutes), frequency of occurrence (1-20 episodes/day; median: 2/day) of head tremor and length of the period without head tremor (1-1,800 days; median: 60 days). Subtle dystonic posturing of the head and neck during head tremor was evident on video recordings of 5 dogs. Certain exceptional conditions such as illness, surgery, some medications, heat, pseudopregnancy, or pregnancy triggered episodes. Two main important forms of episodic head tremor were identified: a familial early-onset form (age dogs were traced back to 1 common sire, also including sporadic cases. Episodic head tremor is an inherited, paroxysmal movement disorder that affects the Doberman pinscher breed. Identification of the causative genes in the future will allow us to obtain a more detailed description of the syndrome. Copyright © 2011 Movement Disorder Society.

  8. Validity of a Screening Question for Head Tremor: An Analysis of Four Essential Tremor Case Samples

    Science.gov (United States)

    Louis, Elan D.; Michalec, Monika

    2014-01-01

    Background The goal of this study was to assess the validity of a screening question for head tremor in essential tremor (ET). There are no published data on this topic, and the knowledge will guide future epidemiological investigations of this disorder. Methods These analyses utilized four distinct patient samples: a population-based study in northern Manhattan, a study of the environmental epidemiology of ET, a genetics study, and a brain repository. Sensitivity was the proportion of ET cases with head tremor on examination who self-reported head tremor. Results The sensitivity of the screening question for head tremor was lowest in the population-based study (31.6%), and higher as well as somewhat similar across the remaining studies (46.7% to 62.2%). Higher sensitivity was associated with tremor of longer duration, presence of voice tremor on examination, female gender, and lower education. The use of the screening question would have increased case ascertainment during the screening phase of these four studies by 1.9%, 4.1%, 10.2% and 20.3%. Conclusions A screening question for head tremor had low to moderate sensitivity in ET. The use of such a screening questionnaire, however, has the potential to increase case ascertainment by as much as 20% in some screening settings. PMID:25323630

  9. Tremor

    Directory of Open Access Journals (Sweden)

    Veronika Kragelj

    2012-01-01

    most frequently used and widely accepted tremor classification divides tremors according to clinical appearance. First, they are roughly divided into resting tremor and action tremor. Action tremor is then subdivided into postural, kinetic, intention, task specific and isometric tremor. Different types of tremor are further combined into tremor syndromes. Causes and mechanisms of tremor are still unclear. Tremor genesis is explained by four hypothetical mechanisms and one of them is assumed to be dominant for each type of tremor. Correct tremor recognition and diagnosis is necessary for appropriate treatment of tremor patients.

  10. Evaluation of Quantitative Measurement Techniques for Head Tremor With Thalamic Deep Brain Stimulation.

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    Chockalingam, Arun; Boggs, Hans; Prusik, Julia; Ramirez-Zamora, Adolfo; Feustel, Paul; Belasen, Abigail; Youn, Youngwon; Fama, Chris; Haller, Jessica; Pilitsis, Julie

    2017-07-01

    Ventralis intermedius thalamic deep brain stimulation (VIM DBS) has shown to be safe and effective for medically refractory essential tremor (ET). We evaluate the use of quantitative tremor measurement methods for head tremor in ET using a "smart" hat and a smartphone application. We enrolled 13 ET patients who previously underwent VIM DBS. Head and arm tremor was measured ON and OFF stimulation using the clinical gold standard Fahn-Tolosa-Marin Tremor Rating Scale (TRS). Results were then compared to two quantitative measurement techniques: Lift Pulse (smartphone application) and modified Nizet (adapted laser point measurement from Nizet et al.). Spearman's rank correlation was used to compare tremor severity and improvement on stimulation using TRS and quantitative methods to measure tremor. Lift Pulse tremor severity measurement significantly correlated with TRS for head (ρ = 0.53, p measurement significantly correlated with TRS for head (ρ = 0.83, p measurement significantly correlated with TRS for arm tremor (ρ = 0.56, p measurement significantly correlated with TRS for head tremor (ρ = 0.53, p measure head and arm tremor severity. We also show the utility of a "smart" hat to measure head tremor. Modified Nizet technique is more effective for measuring head tremor, while Lift Pulse is an effective measure of tremor severity, especially arm tremor improvement. © 2017 International Neuromodulation Society.

  11. Head Tremor in Essential Tremor: “Yes-Yes”, “No-No”, or “Round and Round”?

    Science.gov (United States)

    Robakis, Daphne; Louis, Elan D.

    2015-01-01

    Introduction Essential tremor (ET) is a common yet frequently misdiagnosed movement disorder. One contributing factor may be the dearth of studies that focus on the nuances of clinical phenomenology. A clinical feature that has received relatively little attention is head tremor. Indeed, there is no consensus regarding the predominant direction of head tremor in ET, and no study has examined the clinical correlates of directionality. Methods We identified 51 ET cases with head tremor enrolled in a clinical-epidemiological study of ET at Columbia University. Each had a videotaped neurological examination. Videotapes were viewed and coded by a movement disorders neurologist for head tremor direction (“no-no”, “yes-yes”, or mixed) and continuity (continuous, intermittent, or rare). Direction was correlated with a wide range of clinical features. Results Fourteen cases (27.5%) had “no-no” tremor, 9 (17.6%) had “yes-yes” tremor, and 28 (54.9%) had a mixed tremor. Mixed and “yes-yes” cases were older (p = 0.004) and had a longer tremor duration (p = 0.018) than “no-no” cases. Tremor severity (arms) was higher for mixed cases than for “yes-yes” and “no-no” cases (p = 0.04). More mixed cases had continuously present tremor while more “no-no” cases had rare head tremor (ptremor in ET seems to start as an infrequent tremor in one direction (esp. “no-no”) and becomes more frequent while acquiring additional directionality and a mixed phenotype as the disease progresses. These findings add to our understanding of the clinical spectrum of ET. PMID:26563987

  12. Tremor in dystonia.

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    Pandey, Sanjay; Sarma, Neelav

    2016-08-01

    Tremor has been recognized as an important clinical feature in dystonia. Tremor in dystonia may occur in the body part affected by dystonia known as dystonic tremor or unaffected body regions known as tremor associated with dystonia. The most common type of tremor seen in dystonia patients is postural and kinetic which may be mistaken for familial essential tremor. Similarly familial essential tremor patients may have associated dystonia leading to diagnostic uncertainties. The pathogenesis of tremor in dystonia remains speculative, but its neurophysiological features are similar to dystonia which helps in differentiating it from essential tremor patients. Treatment of tremor in dystonia depends upon the site of involvement. Dystonic hand tremor is treated with oral pharmacological therapy and dystonic head, jaw and voice tremor is treated with injection botulinum toxin. Neurosurgical interventions such as deep brain stimulation and lesion surgery should be an option in patients not responding to the pharmacological treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Bilateral thalamic deep brain stimulation for the treatment of head tremor. Report of two cases.

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    Berk, Caglar; Honey, Christopher R

    2002-03-01

    Isolated head tremor is rare, but can be disabling. The authors' experience with the treatment of limb tremor due to essential tremor led them to consider using bilateral thalamic deep brain stimulation (DBS) in two patients presenting only with disabling head tremor. One patient exhibited no peripheral tremor and the other displayed only a slight upper-limb tremor. Both patients underwent placement of units that apply simultaneous bilateral thalamic DBS. Surgical targets were verified by using intraoperative macrostimulation, and the stimulators were implanted during the same surgery. Patients were videotaped preoperatively and at 2, 4, 6, and 9 months postoperatively during periods in which the stimulators were turned on and off. Videotapes were randomized and rated for resting, postural, and action tremors according to the Fahn clinical rating scale for tremor. Because this scale is not designed for head tremor, the patients were also evaluated on the basis of a functional scale that reflected their quality of life and the amount of disability caused by head tremor. Both patients experienced no tremor after their stimulators were turned on and properly adjusted at the 6th postoperative week. The patients were followed for a total of 9 months and results remained stable throughout this period. No complications were encountered. Bilateral thalamic DBS appears to be an effective and safe treatment for isolated head tremor in patients with essential tremor. The authors present a scale for the functional assessment of head tremor.

  14. Increased risk of head tremor in women with essential tremor: longitudinal data from the Rochester Epidemiology Project.

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    Hardesty, David E; Maraganore, Demetrius M; Matsumoto, Joseph Y; Louis, Elan D

    2004-05-01

    In one cross-sectional study of a community in northern Manhattan, women with essential tremor (ET) were more likely to have head tremor than were men. In that study, patients were seen at one point in time, rather than followed longitudinally. Head tremor often develops after arm tremor, and its appearance in patients with ET may therefore be a function of duration of follow-up. In a second epidemiological study utilizing the Rochester Epidemiology Project, in which ET subjects were followed from disease diagnosis to death, we determined whether there was an association between female gender and head tremor. We utilized the records-linkage system of the Rochester Epidemiology Project to identify ET cases. Records were reviewed and clinical data abstracted by a neurologist specializing in movement disorders. A second neurologist reviewed a subsample of records. There were 107 ET cases (69 women, 38 men) followed for 10.1 +/- 9.1 years from ET diagnosis to death. Head tremor was present in 37 (53.6%) women and 5 (13.2%) men (odds ratio [OR] = 7.6, 95% confidence interval [CI] = 2.7-21.9, P tremor (OR = 6.5, 95% CI = 2.2-19.0, P = 0.001) independent of disease duration. We found in this longitudinal epidemiological study that women with ET were six times more likely to develop head tremor over the course of their illness than were men. The reason for the association between gender and head tremor, which has now been demonstrated in several studies, is not known, but it could reflect gender differences in the distribution of disease pathology within the brain. Copyright 2004 Movement Disorder Society

  15. The ?Head Snap?: A Subtle Clinical Feature During the Finger?Nose?Finger Maneuver in Essential Tremor

    OpenAIRE

    Sternberg, Eliezer J.; Alcalay, Roy N; Levy, Oren A.; Louis, Elan D.

    2013-01-01

    Background Essential tremor is characterized by several hyperkinetic movements, including arm and head tremors. We report another movement of the head in patients with essential tremor, which we term the ?head snap.? This was observed as a jerking motion of the head in some patients while they performed the finger?nose?finger maneuver. Methods We compared the prevalence of the head snap in essential tremor patients vs. Parkinson's disease patients. We also assessed the clinical correlates of ...

  16. Approach to a tremor patient

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    Sharma, Soumya; Pandey, Sanjay

    2016-01-01

    Tremors are commonly encountered in clinical practice and are the most common movement disorders seen. It is defined as a rhythmic, involuntary oscillatory movement of a body part around one or more joints. In the majority of the population, tremor tends to be mild. They have varying etiology; hence, classifying them appropriately helps in identifying the underlying cause. Clinically, tremor is classified as occurring at rest or action. They can also be classified based on their frequency, amplitude, and body part involved. Parkinsonian tremor is the most common cause of rest tremor. Essential tremor (ET) and enhanced physiological tremor are the most common causes of action tremor. Isolated head tremor is more likely to be dystonic rather than ET. Isolated voice tremor could be considered to be a spectrum of ET. Psychogenic tremor is not a diagnosis of exclusion; rather, demonstration of various clinical signs is needed to establish the diagnosis. Severity of tremor and response to treatment can be assessed using clinical rating scales as well as using electrophysiological measurements. The treatment of tremor is symptomatic. Medications are effective in half the cases of essential hand tremor and in refractory patients; deep brain stimulation is an alternative therapy. Midline tremors benefit from botulinum toxin injections. It is also the treatment of choice in dystonic tremor and primary writing tremor. PMID:27994349

  17. Tremor: Tremor:

    OpenAIRE

    Georgiev, Dejan; Kragelj, Veronika; Pirtošek, Zvezdan; Ribarič, Samo

    2012-01-01

    Tremor is one of the most common disorders in the population of patients diagnosed with movement disorders. In the literature we find several classifications and different types of tremors. Each tremor type has its own characteristics. The most frequently used and widely accepted tremor classification divides tremors according to clinical appearance. First, they are roughly divided into resting tremor and action tremor. Action tremor is then subdivided into postural, kinetic, intention, task ...

  18. Tremor

    Science.gov (United States)

    ... overactive thyroid liver or kidney failure anxiety or panic. top What are the symptoms of tremor? Symptoms ... in the arms and legs) and Fragile X syndrome (a disorder marked by a range of intellectual ...

  19. Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

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    Albanese, Alberto; Sorbo, Francesca Del

    2016-01-01

    Background Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods Known forms of syndromes with isolated tremor are reviewed. Diagnostic uncertainties between tremor and dystonia are put into perspective. Results The following isolated tremor syndromes are reviewed: essential tremor, head tremor, voice tremor, jaw tremor, and upper-limb tremor. Their varied phenomenology is analyzed and appraised in the light of a possible relationship with dystonia. Discussion Clinicians making a diagnosis of isolated tremor should remain vigilant for the detection of features of dystonia. This is in keeping with the recent view that isolated tremor may be an incomplete phenomenology of dystonia. PMID:27152246

  20. The "Head Snap": A Subtle Clinical Feature During the Finger–Nose–Finger Maneuver in Essential Tremor

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    Eliezer J. Sternberg

    2013-04-01

    Full Text Available Background:: Essential tremor is characterized by several hyperkinetic movements, including arm and head tremors.  We report another movement of the head in patients with essential tremor, which we term the "head snap." This was observed as a jerking motion of the head in some patients while they performed the finger-nose-finger maneuver. Methods:: We compared the prevalence of the head snap in essential tremor patients vs. Parkinson's disease patients. We also assessed the clinical correlates of the head snap.  Results:: Ten (20% of 50 essential tremor patients exhibited a head snap of any severity (rating ≥0.5 vs. 0 of 50 Parkinson's disease patients (p = 0.001. Patients with head snap had more severe arm tremor on Archimedes spiral drawings (p = 0.019 and were more likely to have head tremor (p = 0.03 than those without it. Conclusions: This sign could be a useful aid in the clinical diagnosis of tremor.

  1. Model of deep non-volcanic tremor part II: episodic tremor and slip

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    Gershenzon, Naum I

    2014-01-01

    Bursts of tremor accompany a moving slip pulse in Episodic Tremor and Slip (ETS) events. The sources of this non-volcanic tremor (NVT) are largely unknown. We have developed a model describing the mechanism of NTV generation. According to this model, NTV is a reflection of resonant-type oscillations excited in a fault at certain depth ranges. From a mathematical viewpoint, tremor (phonons) and slip pulses (solitons) are two different solutions of the sine-Gordon equation describing frictional processes inside a fault. In an ETS event, a moving slip pulse generates tremor due to interaction with structural heterogeneities in a fault and to failures of small asperities. Observed tremor parameters, such as central frequency and frequency attenuation curve, are associated with fault parameters and conditions, such as elastic modulus, effective normal stress, penetration hardness and friction. Model prediction of NTV frequency content is consistent with observations. In the framework of this model it is possible t...

  2. The course of cervical dystonia with head tremor during botulinum toxin type A treatment

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    A. N. Korenko

    2017-01-01

    Full Text Available Objective: to evaluate the efficacy and safety of botulinum toxin type A (BTA injections into the neck muscles to reduce dystonic postures, head tremor, and pain syndrome in patients with cervical dystonia (CD within the first 8 cycles of treatment.Patients and methods. The investigation included 76 patients (26 (34% men and 50 (66% women with CD and dystonic head tremor, who were given BTA injections into the neck muscles for the first time. All the 76 patients received at least one cycle of BTA therapy. At the same type, 18 of these patients received 4 cycles of injections and 36 patients had 8 cycles. Injections were given when the symptoms of CD recurred or increased and the patient needed to be retreated. The interval between the injection cycles was arbitrary, but not less than 12 weeks. The doses of BTA agents per treatment cycle were as follows: Dysport was 400 to 1000 U, xeomin was 50 to 300 U, and Botox 200 to 300 U. The symptoms of CD were assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS and the Tsui scale before the first injection of BTA and injection cycles 4 and 8; the presence or absence of head tremor was recorded.Results. The TWSTRS severity of CD symptoms decreased from 38 [36; 41] to 30 [27; 33] scores by injection cycle 4 (p < 0.001 and to 26 [23; 27] scores by cycle 8 (p<0.01. The Tsui severity of CD reduced from 9.3 [9; 10] to 7.2 [7; 8] scores by injection cycle 4 (p<0.001 and to 6.7 [6; 7] scores by cycle 8. The Tsui tremor scores decreased from 1.9 [1.6; 2.1] to 1.4 [1.1; 1.6] scores by injection cycle 4 and to 1.1 [0.9;1.4] scores by cycle 8 (p<0.01. Tremor completely disappeared in 6 (11% of patients by injection cycle 4 and in 6 (18% patients by cycle 8. According to Section 3 of the TWSTRS, pain intensity was reduced from 9.9 [8.9; 11.0] to 5.0 [3.3; 6.6] scores by injection cycle 4 (p<0.001 and to 2.1 [0.7; 3.6] scores by cycle 8 (p < 0.01; pain regressed completely in 12 (41

  3. Clinical and Breed Characteristics of Idiopathic Head Tremor Syndrome in 291 Dogs: A Retrospective Study

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    Shell, Linda G.; Berezowski, John; Rishniw, Mark; Nibblett, Belle M.; Kelly, Patrick

    2015-01-01

    Objective. To establish signalment and phenomenology of canine idiopathic head tremor syndrome (IHTS), an episodic head movement disorder of undetermined pathogenesis. Design. Retrospective case series. Animals. 291 dogs with IHTS diagnosed between 1999 and 2013. Procedures. Clinical information was obtained from an online community of veterinary information aggregation and exchange (Veterinary Information Network, 777 W Covell Boulevard, Davis, CA 95616) and conducted with their approval. Information on breed, sex, age of onset, tremor description, mentation during the event, effect of distractions and drugs, diagnostics, presence of other problems, and outcome was analyzed. Results. IHTS was found in 24 pure breeds. Bulldogs, Labrador Retrievers, Boxers, and Doberman Pinschers comprised 69%; mixed breeds comprised 17%. Average onset age was 29 months (range: 3 months to 12 years). First episode occurred before 48 months of age in 88%. Vertical (35%), horizontal (50%), and rotational (15%) movements were documented. Possible trigger events were found in 21%. Mentation was normal in 93%. Distractions abated the tremor in 87%. Most dogs did not respond to antiepileptic drugs. Conclusions and Clinical Relevance. This retrospective study documents IHTS in many breeds including Labrador Retrievers, Boxers, and mixed breeds. PMID:26064776

  4. Clinical and Breed Characteristics of Idiopathic Head Tremor Syndrome in 291 Dogs: A Retrospective Study

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    Linda G. Shell

    2015-01-01

    Full Text Available Objective. To establish signalment and phenomenology of canine idiopathic head tremor syndrome (IHTS, an episodic head movement disorder of undetermined pathogenesis. Design. Retrospective case series. Animals. 291 dogs with IHTS diagnosed between 1999 and 2013. Procedures. Clinical information was obtained from an online community of veterinary information aggregation and exchange (Veterinary Information Network, 777 W Covell Boulevard, Davis, CA 95616 and conducted with their approval. Information on breed, sex, age of onset, tremor description, mentation during the event, effect of distractions and drugs, diagnostics, presence of other problems, and outcome was analyzed. Results. IHTS was found in 24 pure breeds. Bulldogs, Labrador Retrievers, Boxers, and Doberman Pinschers comprised 69%; mixed breeds comprised 17%. Average onset age was 29 months (range: 3 months to 12 years. First episode occurred before 48 months of age in 88%. Vertical (35%, horizontal (50%, and rotational (15% movements were documented. Possible trigger events were found in 21%. Mentation was normal in 93%. Distractions abated the tremor in 87%. Most dogs did not respond to antiepileptic drugs. Conclusions and Clinical Relevance. This retrospective study documents IHTS in many breeds including Labrador Retrievers, Boxers, and mixed breeds.

  5. Features of treatment of cervical dystonia associated with head tremor with botulinum toxin type A drugs under electro myographic control

    Directory of Open Access Journals (Sweden)

    A. N. Korenko

    2016-01-01

    Full Text Available The study was aimed to evaluate the efficacy and safety of injections of botulinum toxin typeA (BTA in the neck muscles under electromyographic control and without it to reduce head tremor, muscle tone and dystonic postures, as well as pain in patients with cervical dystonia (CD. 49 patients with CD and dystonic head tremor who received injections of BTA were examined. 33 (67 % patients received Dysport in an average dose of 695 (627; 762 units, 15 (31 % patients received Xeomin in an average dose of 262 (227; 297 units and 1 (2 % patient received 300 units of Botox. 16 (33 % patients received injections under EMGcontrol. The level of symptoms of CD and tremor before and 4 weeks after the treatment were measured by the TWSTRS and Tsui scales. Evaluation of the treatment efficacy was carried out using the patientreported Clinical Global Improvement (CGI scale, and the presence or absence of head tremor after injection was also recorded. The TWSTRS score decreased from 39 (36, 42 to 24 (21, 26, the TZUI score decreased from 9.8 (9, 10 to 4.9 (4, 6 in 4 weeks after injection (p <0.001. The level of tremor measured by Tsui scale decreased from 2.1 (1.7, 2.4 and 0.7 points (0,5; 0,9 (p <0.001. In 24 (49 % cases, complete disappearance of tremor was noted in 4 weeks after injection. Complete regression of tremor was observed significantly more frequently in patients with torticollis who received injections with EMG-control in 10(71 % cases vs. 8(32 % without it (p <0.05. 28(57 % patients noted moderate or significant improvement on the CGI scale. Pain decreased from 5.4 (3.9, 6.9 points to 2.4 (1.3, 3.6 (p <0.001 according to section 3 of TWSTRS scale, pain completely regressed in 15 (52 % patients. BTA injections are highly effective and safe treatment of CD symptoms such as dystonic posture, pain and dystonic tremor. BTA injections in the neck muscles under EMGcontrol can improve outcome in patients with torticollis associated with

  6. Functional tremor.

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    Schwingenschuh, P; Deuschl, G

    2016-01-01

    Functional tremor is the commonest reported functional movement disorder. A confident clinical diagnosis of functional tremor is often possible based on the following "positive" criteria: a sudden tremor onset, unusual disease course, often with fluctuations or remissions, distractibility of the tremor if attention is removed from the affected body part, tremor entrainment, tremor variability, and a coactivation sign. Many patients show excessive exhaustion during examination. Other somatizations may be revealed in the medical history and patients may show additional functional neurologic symptoms and signs. In cases where the clinical diagnosis remains challenging, providing a "laboratory-supported" level of certainty aids an early positive diagnosis. In rare cases, in which the distinction from Parkinson's disease is difficult, dopamine transporter single-photon emission computed tomography (DAT-SPECT) can be indicated. © 2016 Elsevier B.V. All rights reserved.

  7. Intention tremor after head injury. Clinical features and computed tomographic findings

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    Iwadate, Yasuo; Saeki, Naokatsu; Namba, Hiroki; Odaki, Masaru; Oka, Nobuo.

    1989-02-01

    Eight cases of intention tremor as a late complication of head injury were investigated. The patients ranged in age from 3 to 24 years. All received severe head injuries and lapsed into coma immediately afterward (Glasgow Coma Scale scores /le/8). Six patients exhibited decerebration or decortication. Hemiparesis was present in six cases and oculomotor nerve palsy in four. In the chronic stage, all patients displayed some degree of impairment of higher cortical function and five had dysarthria and/or ataxia. Initial computed tomography (CT) scans within 3 hours after the injury were obtained in five cases, of which four showed a hemorrhagic lesion in the midbrain or its surroundings. Other CT findings were diffuse cerebral swelling (four cases), intraventricular hemorrhage (three), and multiple hemorrhagic lesions (two). In the chronic stage, generalized cortical atrophy or ventricular enlargement was noted in five cases. These clinical features and CT findings indicate diffuse brain damage as well as midbrain damage and may reflect shearing injury. (author).

  8. What is essential tremor?

    Science.gov (United States)

    Elble, Rodger J

    2013-01-01

    Classic essential tremor is a clinical syndrome of action tremor in the upper limbs (at least 95% of patients) and less commonly the head, face/jaw, voice, tongue, trunk, and lower limbs, in the absence of other neurologic signs. However, the longstanding notion of that essential tremor is a monosymptomatic tremor disorder is being challenged by a growing literature describing associated disturbances of tandem walking, personality, mood, hearing and cognition. There is also epidemiologic, pathologic and genetic evidence that essential tremor is pathophysiologically heterogeneous. Misdiagnosis of essential tremor is common because clinicians frequently overlook other neurologic signs and because action tremor in the hands is caused by many conditions, including dystonia, Parkinson disease and drug-induced tremor. Thus, essential tremor is nothing more than a syndrome of idiopathic tremulousness, and the challenge for researchers and clinicians is to find specific etiologies of this syndrome. PMID:23591755

  9. Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

    OpenAIRE

    Alberto Albanese; Francesca Del Sorbo

    2016-01-01

    Background: Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods: Known form...

  10. Essential tremor

    Science.gov (United States)

    Tremor - essential; Familial tremor; Tremor - familial; Benign essential tremor; Shaking - essential tremor ... ET is the most common type of tremor. Everyone has some tremor, but the movements are often so small that they can't be seen. ET affects both men and women. ...

  11. Superselective Thalamotomy in the Most Lateral Part of the Ventralis Intermedius Nucleus for Controlling Essential and Parkinsonian Tremor.

    Science.gov (United States)

    Hirato, Masafumi; Miyagishima, Takaaki; Takahashi, Akio; Yoshimoto, Yuhei

    2018-01-01

    The minimum and essential thalamic areas for reducing tremor were investigated in cases treated by superselective thalamotomy in the most lateral part of the ventralis intermedius nucleus (mlp-VIM). Stereotactic superselective VIM thalamotomy with depth microrecording was performed in 21 patients with essential tremor (ET) and 15 patients with tremor-dominant Parkinson disease (PD). A very small and narrow (axial plane) therapeutic lesion was formed as a square on the sagittal plane and inverse V on the axial plane in the mlp-VIM, which covered the kinesthetic response area topographically related to tremor. Patients with ET were followed up for 4.7 ± 3.0 years and patients with PD for 7.9 ± 3.9 years. Almost complete tremor control was achieved in all patients immediately after surgery and continued for up to 8 years. A few adverse events were recognized but disappeared within 1 month without 1 patient with thalamic hemorrhage. The medial border of the therapeutic lesion was significantly more lateral in both patients with ET and patients with PD than the calculated standard target point and was in patients with PD than in patients with ET. The mean width was only about 2.4 mm. The individual differences of the adequate location of the therapeutic lesion were significantly greater in the ET than in the PD group. The important area for reducing tremor was small and narrow and was located in the mlp-VIM, where the proprioceptive ascending signals from the tremor-dominant body part are conducted. Superselective thalamotomy in the mlp-VIM was safe and effective for the long-term in patients with ET and PD. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Volcanic tremor masks its seismogenic source: Results from a study of noneruptive tremor recorded at Mount St. Helens, Washington

    Science.gov (United States)

    Denlinger, Roger P.; Moran, Seth C.

    2014-01-01

    On 2 October 2004, a significant noneruptive tremor episode occurred during the buildup to the 2004–2008 eruption of Mount St. Helens (Washington). This episode was remarkable both because no explosion followed, and because seismicity abruptly stopped following the episode. This sequence motivated us to consider a model for volcanic tremor that does not involve energetic gas release from magma but does involve movement of conduit magma through extension on its way toward the surface. We found that the tremor signal was composed entirely of Love and Rayleigh waves and that its spectral bandwidth increased and decreased with signal amplitude, with broader bandwidth signals containing both higher and lower frequencies. Our modeling results demonstrate that the forces giving rise to this tremor were largely normal to conduit walls, generating hybrid head waves along conduit walls that are coupled to internally reflected waves. Together these form a crucial part of conduit resonance, giving tremor wavefields that are largely a function of waveguide geometry and velocity. We find that the mechanism of tremor generation fundamentally masks the nature of the seismogenic source giving rise to resonance. Thus multiple models can be invoked to explain volcanic tremor, requiring that information from other sources (such as visual observations, geodesy, geology, and gas geochemistry) be used to constrain source models. With concurrent GPS and field data supporting rapid rise of magma, we infer that tremor resulted from drag of nearly solid magma along rough conduit walls as magma was forced toward the surface.

  13. Essential Tremor

    Science.gov (United States)

    ... the person's ability to perform certain tasks or activities of daily living. In many people the tremor may be mild ... the person's ability to perform certain tasks or activities of daily living. In many people the tremor may be mild ...

  14. Essential Tremor

    Science.gov (United States)

    ... Tremor Last Updated: July 2017 Categories: Family Health, Men, Seniors, WomenTags: adult, elderly, higher, multiple sclerosis, Neurologic, older adults, Parkinson Disease Family Health, Men, Seniors, Women ...

  15. Diagnosis and Treatment of Common Forms of Tremor

    Science.gov (United States)

    Puschmann, Andreas; Wszolek, Zbigniew K.

    2014-01-01

    Tremor is the most common movement disorder presenting to an outpatient neurology practice and is defined as a rhythmical, involuntary oscillatory movement of a body part. The authors review the clinical examination, classification, and diagnosis of tremor. The pathophysiology of the more common forms of tremor is outlined, and treatment options are discussed. Essential tremor is characterized primarily by postural and action tremors, may be a neurodegenerative disorder with pathologic changes in the cerebellum, and can be treated with a wide range of pharmacologic and nonpharmacologic methods. Tremor at rest is typical for Parkinson’s disease, but may arise independently of a dopaminergic deficit. Enhanced physiologic tremor, intention tremor, and dystonic tremor are discussed. Further differential diagnoses described in this review include drug- or toxin-induced tremor, neuropathic tremor, psychogenic tremor, orthostatic tremor, palatal tremor, tremor in Wilson’s disease, and tremor secondary to cerebral lesions, such as Holmes’ tremor (midbrain tremor). An individualized approach to treatment of tremor patients is important, taking into account the degree of disability, including social embarrassment, which the tremor causes in the patient’s life. PMID:21321834

  16. Essential Tremor (ET): Coping Tips for Everyday Living

    Science.gov (United States)

    ... upended facial tissue box to steady your head. Writing Print rather than write script. Write in small ... News IETF Accepting Proposals for Grants Relevant to Essential Tremor Chris Kennedy’s Mild Hereditary Tremor No Big ...

  17. Essential Tremor Is More Than a Tremor

    Science.gov (United States)

    ... Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens ... Click to print (Opens in new window) Essential Tremor is More Than a Tremor Providing a voice ...

  18. Essential Tremor Is More Than a Tremor

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    Full Text Available ... Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens ... Click to print (Opens in new window) Essential Tremor is More Than a Tremor Providing a voice ...

  19. Neural computational modeling reveals a major role of corticospinal gating of central oscillations in the generation of essential tremor

    Directory of Open Access Journals (Sweden)

    Hong-en Qu

    2017-01-01

    Full Text Available Essential tremor, also referred to as familial tremor, is an autosomal dominant genetic disease and the most common movement disorder. It typically involves a postural and motor tremor of the hands, head or other part of the body. Essential tremor is driven by a central oscillation signal in the brain. However, the corticospinal mechanisms involved in the generation of essential tremor are unclear. Therefore, in this study, we used a neural computational model that includes both monosynaptic and multisynaptic corticospinal pathways interacting with a propriospinal neuronal network. A virtual arm model is driven by the central oscillation signal to simulate tremor activity behavior. Cortical descending commands are classified as alpha or gamma through monosynaptic or multisynaptic corticospinal pathways, which converge respectively on alpha or gamma motoneurons in the spinal cord. Several scenarios are evaluated based on the central oscillation signal passing down to the spinal motoneurons via each descending pathway. The simulated behaviors are compared with clinical essential tremor characteristics to identify the corticospinal pathways responsible for transmitting the central oscillation signal. A propriospinal neuron with strong cortical inhibition performs a gating function in the generation of essential tremor. Our results indicate that the propriospinal neuronal network is essential for relaying the central oscillation signal and the production of essential tremor.

  20. 1 CFR 21.19 - Composition of part headings.

    Science.gov (United States)

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Composition of part headings. 21.19 Section 21.19 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION OF DOCUMENTS SUBJECT TO CODIFICATION General Headings § 21.19 Composition...

  1. Unusual Wrist Tremor: Unilateral Isometric Tremor?

    Science.gov (United States)

    Zesiewicz, Theresa; Vu, Tuan; Carranza, Michael A.; Appelbaum, Rachel; Snyder, Madeline; Staffetti, Joseph S.; Allison, Kevin G.; Shimberg, William R.; Louis, Elan D.

    2014-01-01

    Background Tremors may be difficult to classify. Case Report An 83-year-old male presented with an unusual left wrist tremor. The tremor could be reproducibly elicited by making a fist or carrying a weighted object (e.g., a shopping bag, bottle of water) of approximately 1 lb or more, and it intensified with heavier weights. The tremor was difficult to classify, although it shared features with isometric tremor. Discussion This specific presentation of tremor has not been reported previously. We hope that the detailed description we provide will aid other neurologists who encounter this or similar tremors in their clinics. PMID:24455450

  2. Unusual Forehead Tremor in Four Patients with Essential Tremor

    OpenAIRE

    Jordi Gascón-Bayarri; Jaume Campdelacreu; Màtil Calopa; Serge Jaumà; Laura Bau; Mònica Povedano; Jordi Montero

    2012-01-01

    Forehead tremor has only been reported in two patients with essential tremor, one with rhythmic tremor and the other with dystonic tremor. We report 4 new patients with essential tremor who present a 4–6 Hz frontal tremor registered by electromyography and unusual features like frontal tremor preceding limb tremor or unilateral involvement. Frontal tremor is present in some patients with essential tremor, sometimes preceding limb tremor. Treatment with botulinum toxin may be useful.

  3. Unusual Forehead Tremor in Four Patients with Essential Tremor

    Directory of Open Access Journals (Sweden)

    Jordi Gascón-Bayarri

    2012-01-01

    Full Text Available Forehead tremor has only been reported in two patients with essential tremor, one with rhythmic tremor and the other with dystonic tremor. We report 4 new patients with essential tremor who present a 4–6 Hz frontal tremor registered by electromyography and unusual features like frontal tremor preceding limb tremor or unilateral involvement. Frontal tremor is present in some patients with essential tremor, sometimes preceding limb tremor. Treatment with botulinum toxin may be useful.

  4. UK semiconductor tracker parts head for CERN

    CERN Multimedia

    Holland, Colin

    2005-01-01

    The last of the 4 barrels that make up the central part of the Semiconductor Tracker (SCT), the heart of the biggest physics collaboration in the world have left Oxford for its new home at the European Particle Physics Laboratory, CERN, near Geneva

  5. Is tremor in dystonia a phenotypic feature of dystonia?

    Science.gov (United States)

    Defazio, Giovanni; Conte, Antonella; Gigante, Angelo F; Fabbrini, Giovanni; Berardelli, Alfredo

    2015-03-10

    To understand better the features and mechanisms distinguishing tremor in dystonia, we reviewed the epidemiologic, clinical, and neurophysiologic data in patients with dystonia and tremor. Clinical studies suggest that tremor starts at or after dystonia onset in body parts affected or unaffected by dystonia. Tremor in dystonia manifests during posture or voluntary movements even though some dystonic patients may have tremor at rest. Prevalence rates for tremor in dystonia are higher in patients with adult-onset dystonia and cervical dystonia than in other dystonias and highest in patients in whom dystonia spreads. Neurophysiologic investigations in patients with dystonia and tremor show reduced reciprocal inhibition between agonist and antagonist upper limb muscles, a lack of brainstem interneuronal inhibition, and abnormal sensory integration. The neurophysiologic abnormalities in patients with dystonia and tremor resemble those in dystonia but differ from those described in essential tremor. Tremor is a phenotypic motor feature in dystonia. © 2015 American Academy of Neurology.

  6. Epidemiology, diagnosis and differential diagnosis in Parkinson's disease tremor.

    Science.gov (United States)

    Baumann, Christian R

    2012-01-01

    The epidemiology of tremor in Parkinson's disease is not well examined. The prevalence of Parkinson's disease is about 100-300 per 100,000, and the majority (70-100%) of these patients may develop tremor during the course of the disorder. The expression of tremor is also influenced by the genetic background of selected patients. On the other hand, Parkinson patients with a predominant tremor phenotype may have a more favourable prognosis in terms of mortality and the development of motor and non-motor complications. The diagnosis of Parkinson tremor is based on a clinical diagnosis of both underlying Parkinson's disease and on the tremor itself. Tremor is a rhythmical, involuntary oscillatory movement of a body part, and includes resting tremor, action tremor including postural and kinetic tremor. The classical type is resting tremor, but other phenotypes may also occur. Misdiagnoses between Parkinson tremor and essential tremor are relatively common. Electrophysiological and functional imaging examinations can be useful in the distinction of the two, but both approaches suffer from some limitations. In general, essential tremor and other tremor forms can be distinguished from Parkinson tremor by their frequency and their expression with different activation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Tectonic tremor

    Science.gov (United States)

    Shelly, David R.

    2016-01-01

    Tectonic, non-volcanic tremor is a weak vibration of ground, which cannot be felt by humans but can be detected by sensitive seismometers. It is defined empirically as a low-amplitude, extended duration seismic signal associated with the deep portion (∼20–40 km depth) of some major faults. It is typically observed most clearly in the frequency range of 2–8 Hz and is depleted in energy at higher frequencies relative to regular earthquakes.

  8. Incidence rates of cranial tremors in essential tremor: a prospective, longitudinal study.

    Science.gov (United States)

    Michalec, Monika; Gillman, Art; Louis, Elan D

    2014-01-01

    Cranial (head, jaw) tremors develop in a sizable number of essential tremor (ET) patients. They are particularly important because they are a significant source of embarrassment and are especially resistant to treatment. There are no data on the rate at which ET patients develop these cranial tremors. Our aim was to estimate the incidence rate of head and jaw tremors in ET. Cases, enrolled in a prospective, longitudinal study, were evaluated at baseline and one follow-up visit. The in-person evaluation included questionnaires and a videotaped neurological examination, which was reviewed by a senior movement disorder neurologist for the presence/absence of head and jaw tremors. The mean time between baseline and follow-up assessments was 6.3 ± 2.4 (median = 6.0; range = 1.5-12.4 years). Five (6.3%) of 79 cases developed head tremor by follow-up (incidence rate = 1,012 per 100,000 person years; 95% confidence interval [CI] = 0-3,219). Twelve (10.6%) of 113 cases developed jaw tremor by follow-up (incidence rate = 1,692 per 100,000 person years; 95% CI = 0-1,692). These epidemiological data were designed to assist physicians in counseling ET patients when they ask about their risks of developing cranial tremors. © 2014 S. Karger AG, Basel.

  9. Essential Tremor Is More Than a Tremor

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    Full Text Available ... Google+ (Opens in new window) Click to email this to a friend (Opens in new window) Click to print ( ... in new window) Essential Tremor is More Than a Tremor Providing a voice for people with essential ...

  10. Essential Tremor Is More Than a Tremor

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    Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > ... Essential Tremor Foundation Seeks Grant Proposals Raving Fan Home About the IETF Volunteer For Healthcare Providers Giving ...

  11. Essential Tremor Is More Than a Tremor

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    Full Text Available ... in new window) Click to email this to a friend (Opens in new window) Click to print ( ... in new window) Essential Tremor is More Than a Tremor Providing a voice for people with essential ...

  12. Essential Tremor Is More Than a Tremor

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    Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > ... Parkinson’s disease and essential tremor symptoms Raving Fan Home About the IETF Volunteer For Healthcare Providers Giving ...

  13. Essential Tremor Is More Than a Tremor

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    Full Text Available ... Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new ... of this life-altering neurological condition. Meet our video volunteers: Recent News Chris Kennedy’s mild hereditary tremor ...

  14. More Time with Tremor: The Experience of Essential Tremor Versus Parkinson's Disease Patients

    Science.gov (United States)

    Louis, Elan D.

    2016-01-01

    Background A broad range of tremors occur in patients with essential tremor and Parkinson's disease; despite this, there are virtually no published data that focus on the patient perspective. The aims were to (1) assess the subjective experience of tremor, comparing essential tremor and Parkinson's disease patients, and (2) assess the clinical correlates of that experience (i.e., what specific clinical characteristics were associated with more experienced tremor)? Methods 121 essential tremor and 100 Parkinson's disease cases enrolled in a cross-sectional, clinical-epidemiological study underwent a detailed clinical assessment, which included a series of standardized questionnaires and neurological examination. The question, “On a typical day, how many waking hours do you have tremor in any body part?”, was also administered. Results Essential tremor cases reported more than three times the median number of waking hours experiencing tremor than Parkinson's disease cases: 10.1 ± 7.8 (median 10.0) vs. 5.5 ± 6.3 (median 3.0) hours (ptremor) reported spending ≥16 hours/day shaking. Greater number of hours experiencing tremor was associated with female gender, higher Center for Epidemiological Studies Depression Scale scores, greater perceived disability and, in essential tremor, higher Essential Tremor Embarrassment Assessment scores. Conclusions Essential tremor patients reported more than three times the median number of waking hours experiencing tremor than Parkinson's disease patients. Certain clinical characteristics tracked with more reported tremor, and the number of such hours had clear clinical ramifications - greater number of hours was associated with both psycho-social and functional consequences. PMID:27430000

  15. Milestones in tremor research.

    Science.gov (United States)

    Elble, Rodger; Deuschl, Günther

    2011-05-01

    Tremor is one of the most frequent movement disorders and covers a wide spectrum of entities summarized in the 1998 consensus statement of the Movement Disorder Society. Essential tremor and Parkinson tremor are most common and are also the most thoroughly studied. Major progress has occurred in the clinical semiology, neuroimaging, epidemiology, and pathophysiology of tremors. Pathology and genetic research are rapidly growing fields of study. Recently described tremor entities include orthostatic tremor, dystonic tremor, cortical tremor, and thalamic tremor. Treatment research methodology has improved substantially, but few double-blind controlled trials have been published. Deep brain stimulation is the most effective treatment for most tremors but is reserved for advanced cases. Copyright © 2011 Movement Disorder Society.

  16. Unusual Wrist Tremor: Unilateral Isometric Tremor?

    Directory of Open Access Journals (Sweden)

    Theresa A. Zesiewicz

    2014-01-01

    Full Text Available Background: Tremors may be difficult to classify.Case Report: An 83‐year‐old male presented with an unusual left wrist tremor. The tremor could be reproducibly elicited by making a fist or carrying a weighted object (e.g., a shopping bag, bottle of water of approximately 1 lb or more, and it intensified with heavier weights. The tremor was difficult to classify, although it shared features with isometric tremor.Discussion: This specific presentation of tremor has not been reported previously. We hope that the detailed description we provide will aid other neurologists who encounter this or similar tremors in their clinics.

  17. Essential tremor and cerebellar dysfunction clinical and kinematic analysis of intention tremor.

    Science.gov (United States)

    Deuschl, G; Wenzelburger, R; Löffler, K; Raethjen, J; Stolze, H

    2000-08-01

    The cerebellum is assumed to play a major role in the pathophysiology of essential tremor (ET). As intention tremor is considered one of the classical features of cerebellar disease, we have assessed a large group of patients with ET for the semiology of the tremor and have performed objective quantitative analysis of a grasping movement in patients with ET, cerebellar disease and a normal control group. We found 25% of the patients to have a moderate or severe kinetic tremor with clear-cut features of a classical intention tremor. Another 33% of the patients had a mild intentional component of their kinetic tremor. Patients with intention tremor (ET(IT)) did not differ from those with predominant postural tremor (ET(PT)) with respect to alcohol sensitivity of the tremor and the frequency of a family history. ET(IT) patients were older and more often showed head and trunk involvement. The onset of this intention tremor has been assessed retrospectively. It was found to begin at a randomly distributed time interval after the onset of the postural tremor, but older patients had a shorter time to development of intention tremor. Quantitative accelerometry of postural tremor showed similar tremor frequencies in both patient groups, but ET(IT) patients had a slightly larger tremor amplitude. Quantitative analysis of a grasping movement using an infrared-camera system was performed in two subgroups of the patients with ET(PT) and ET(IT) and control groups with cerebellar disease or normal subjects. The intention tremor could be quantified objectively as an increased amplitude of curvature during the deceleration and target phase of the movement. The amplitude measurements of intention tremor were clearly abnormal and of comparable magnitude for ET(PT) and cerebellar disease. Additionally, the patients with ET(IT) had a significantly slowed grasping movement during the deceleration and target period. Hypermetria was significantly increased for the patients with ET(IT) and

  18. Task Specific Tremors.

    Science.gov (United States)

    Friedman, Joseph H

    2015-07-01

    A patient reported bilateral hand tremors when writing but not with other tasks. These "task specific" tremors are considered subcategories of essential tremor. Primary writing tremor, in which the tremor occurs only with writing, is probably the most common. The important teaching point is that the "standard" tremor assessment, watching the patient holding a sustained posture and touching his finger to the examiner's and then back to the nose is not adequate. Patients should be tested doing the activity that causes them the most difficulty.

  19. The phenomenology of parkinsonian tremor.

    Science.gov (United States)

    Deuschl, Günther; Papengut, Frank; Hellriegel, Helge

    2012-01-01

    The definition of Parkinsonian tremor covers all different forms occurring in Parkinson's disease. The most common form is rest tremor, labelled as typical Parkinsonian tremor. Other variants cover also postural and action tremors. Data support the notion that suppression of rest tremor may be more specific for PD tremors. Several differential diagnoses like rest tremor in ET, dystonic tremor, psychogenic tremor and Holmes' tremor may be misinterpreted as PD-tremor. Tests and clinical clues to separate them are presented. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Treatment of Essential Tremor

    Science.gov (United States)

    ... for PATIENTS and their FAMILIES TREATMENT OF ESSENTIAL TREMOR This fact sheet is provided to help you understand which therapies help treat essential tremor. Neurologists from the American Academy of Neurology are ...

  1. Tremor in the elderly

    DEFF Research Database (Denmark)

    Deuschl, Günther; Petersen, Inge; Lorenz, Delia

    2015-01-01

    Isolated tremor in the elderly is commonly diagnosed as essential tremor (ET). The prevalence of tremor increases steeply with increasing age, whereas hereditary tremor is becoming less common. Moreover, late-manifesting tremor seems to be associated with dementia and earlier mortality. We...... hypothesize that different entities underlie tremor in the elderly. Two thousand four hundred forty-eight subjects from the Longitudinal Study of Aging Danish Twins older than 70 y answered screening questions for ET in 2001. Two thousan fifty-six (84%) participants drew Archimedes spirals to measure...... their tremor severity, and classical aging phenotypes were assessed. A subgroup of 276 individuals fulfilling either screening criteria for ET or being controls were personally assessed. Medications and mortality data are available. The spiral score increased with age. The spiral score correlated with tremor...

  2. Tremor-related quality of life: A comparison of essential tremor vs. Parkinson's disease patients.

    Science.gov (United States)

    Louis, Elan D; Machado, Duarte G

    2015-07-01

    Tremor-related quality of life is a multi-dimensional concept that reflects the physical, emotional and other health effects of tremor. Curiously, tremor-related quality of life has never been directly compared in patients with the two major tremor disorders, essential tremor (ET) and Parkinson's disease (PD). We performed a head-to-head comparison of ET with PD patients. The Quality of Life in Essential Tremor (QUEST) questionnaire was administered to 103 ET and 103 matched PD patients enrolled in a clinical-epidemiological study in New York. The QUEST total score and QUEST physical subscore were higher in ET than PD patients (both p writing, using a typewriter/computer, fixing small things, dressing, eating, and holding reading material. Tremor is a clinical entity that can have numerous effects on patients. While there were relative differences between the two major tremor disorders, ET and PD, in absolute terms, tremor impacted on several domains of quality of life, from physical to psychosocial, in a large proportion of ET and PD patients. Attempts to judge the efficacy of treatments for tremor, whether pharmacological or surgical, should consider its broad impact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Nontraumatic head and neck injuries: a clinical approach. Part 2.

    Science.gov (United States)

    Brea Álvarez, B; Esteban García, L; Tuñón Gómez, M; Cepeda Ibarra, Y

    Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons. As explained in the first part of this update, these entities affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Maintaining the same approach as in the first part, focusing on the clinical presentations in the emergency department rather than on the anatomic regions affected, we will study the entities that present with two patterns: those that present with a combination of cervical numbness, dysphagia, and dyspnea and those that present with acute sensory deficits. In the latter group, we will specifically focus on visual deficits, because this is the most common symptom that calls for urgent imaging studies. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Therapeutic advances in tremor.

    Science.gov (United States)

    Fasano, Alfonso; Deuschl, Günther

    2015-09-15

    Although tremor is a highly prevalent movement disorder, progress in this field is limited because of the poor understanding of many of the underlying conditions. This review summarizes recent treatment attempts since 2013. For essential tremor, recent innovations are phase I or II studies of Octanol, several clinically relevant refinements for deep brain stimulation, and the development of the new magnetic resonance imaging guided focused ultrasound technique. Further new invasive and noninvasive electrical and magnetic stimulation techniques have been tested for essential tremor and parkinsonian tremor. For multiple sclerosis tremor, some open-label observations have shown positive results (natalizumab, dalfampridine, levetiracetam), whereas controlled trials using cannabinoids have been negative. Functional tremor has shown a positive response to retrainment. Neuroprosthetic devices have been tested in a variety of tremor conditions. Several promising medical and surgical treatment trials are underway and will be completed shortly. © 2015 International Parkinson and Movement Disorder Society.

  5. Lessons from (triggered) tremor

    Science.gov (United States)

    Gomberg, Joan

    2010-01-01

    I test a “clock-advance” model that implies triggered tremor is ambient tremor that occurs at a sped-up rate as a result of loading from passing seismic waves. This proposed model predicts that triggering probability is proportional to the product of the ambient tremor rate and a function describing the efficacy of the triggering wave to initiate a tremor event. Using data mostly from Cascadia, I have compared qualitatively a suite of teleseismic waves that did and did not trigger tremor with ambient tremor rates. Many of the observations are consistent with the model if the efficacy of the triggering wave depends on wave amplitude. One triggered tremor observation clearly violates the clock-advance model. The model prediction that larger triggering waves result in larger triggered tremor signals also appears inconsistent with the measurements. I conclude that the tremor source process is a more complex system than that described by the clock-advance model predictions tested. Results of this and previous studies also demonstrate that (1) conditions suitable for tremor generation exist in many tectonic environments, but, within each, only occur at particular spots whose locations change with time; (2) any fluid flow must be restricted to less than a meter; (3) the degree to which delayed failure and secondary triggering occurs is likely insignificant; and 4) both shear and dilatational deformations may trigger tremor. Triggered and ambient tremor rates correlate more strongly with stress than stressing rate, suggesting tremor sources result from time-dependent weakening processes rather than simple Coulomb failure.

  6. Essential Tremor Is More Than a Tremor

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    Full Text Available ... Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) Click to share on Google+ (Opens in new window) ...

  7. Essential Tremor Is More Than a Tremor

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    Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new window) Click ...

  8. Essential Tremor Is More Than a Tremor

    Medline Plus

    Full Text Available ... Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new ... of this life-altering neurological condition. Meet our video volunteers: Recent News IETF Accepting Proposals for Grants ...

  9. Essential Tremor Is More Than a Tremor

    Medline Plus

    Full Text Available ... Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) Click to share on Google+ (Opens in new window) Click ...

  10. Essential Tremor Is More Than a Tremor

    Medline Plus

    Full Text Available ... reaching out to healthcare providers and the general public. This six-minute video tells the stories of six people living with ET. It goes beyond ... Essential Tremor Foundation Seeks Grant Proposals FDA approves ...

  11. Validity of clinical and patient ratings of tremor disability among older adults.

    Science.gov (United States)

    Lundervold, Duane A; Pahwa, Rajesh; Ament, Patrick A; Corbin, D Edward

    2003-10-01

    To evaluate the validity of the clinical tremor disability interview using a performance-based measure, patient ratings of tremor disability, and bedside tremor severity ratings of upper extremity (UE) action/intention (A/I) and postural (P) tremor. Sixteen older adult essential tremor patients (mean age=75.4 years, sd=5.7 years) took part in a study evaluating the validity of clinical and self-rating scales of tremor disability. A neurologist obtained bedside clinical ratings of UE A/I and P tremor of each limb and completed a clinical tremor disability rating. A second investigator, blind to neurological exam results obtained a clinical disability rating using the same measure, patient rated tremor disability ratings and conducted a performance-based disability assessment. Clinical tremor disability ratings were not significantly related to functional performance-based or patient ratings of tremor disability. Bedside clinical ratings of tremor severity also were not associated with clinical or patient-rated tremor disability. Patient ratings were significantly correlated with performance-based ratings. Further research is needed to validate a brief, sensitive clinical rating scale of tremor disability among older adults. Use of bedside ratings of tremor severity may be problematic and possibly estimate tremor disability. Empirical evaluation of differences in rating methods needs to be directly addressed.

  12. Genetics Home Reference: essential tremor

    Science.gov (United States)

    ... types of activities, such as eating, drinking, or writing. Essential tremor can also occur when the muscles are ... the tremor may affect the voice (vocal tremor). Essential ... using eating utensils, writing, shaving, or applying makeup, and in some cases ...

  13. Advances in primary writing tremor.

    Science.gov (United States)

    Hai, Chen; Yu-ping, Wang; Hua, Wei; Ying, Sun

    2010-11-01

    Primary writing tremor (PWT) is considered to be a type of task-specific tremor in which tremor predominantly occurs and interferes with handwriting. The pathophysiology of PWT is not clear. Primary writing tremor may be a variant of essential tremor, a type of focal dystonia such as writer's cramp, or a separate nosological entity. Botulinum toxin injections and deep brain stimulation may be treatment choices for primary writing tremor. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. The nature of tremor circuits in parkinsonian and essential tremor

    Science.gov (United States)

    Cagnan, Hayriye; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Cheeran, Binith; Fitzgerald, James; Green, Alexander L.; Aziz, Tipu

    2014-01-01

    Tremor is a cardinal feature of Parkinson’s disease and essential tremor, the two most common movement disorders. Yet, the mechanisms underlying tremor generation remain largely unknown. We hypothesized that driving deep brain stimulation electrodes at a frequency closely matching the patient’s own tremor frequency should interact with neural activity responsible for tremor, and that the effect of stimulation on tremor should reveal the role of different deep brain stimulation targets in tremor generation. Moreover, tremor responses to stimulation might reveal pathophysiological differences between parkinsonian and essential tremor circuits. Accordingly, we stimulated 15 patients with Parkinson’s disease with either thalamic or subthalamic electrodes (13 male and two female patients, age: 50–77 years) and 10 patients with essential tremor with thalamic electrodes (nine male and one female patients, age: 34–74 years). Stimulation at near-to tremor frequency entrained tremor in all three patient groups (ventrolateral thalamic stimulation in Parkinson’s disease, P = 0.0078, subthalamic stimulation in Parkinson’s disease, P = 0.0312; ventrolateral thalamic stimulation in essential tremor, P = 0.0137; two-tailed paired Wilcoxon signed-rank tests). However, only ventrolateral thalamic stimulation in essential tremor modulated postural tremor amplitude according to the timing of stimulation pulses with respect to the tremor cycle (e.g. P = 0.0002 for tremor amplification, two-tailed Wilcoxon rank sum test). Parkinsonian rest and essential postural tremor severity (i.e. tremor amplitude) differed in their relative tolerance to spontaneous changes in tremor frequency when stimulation was not applied. Specifically, the amplitude of parkinsonian rest tremor remained unchanged despite spontaneous changes in tremor frequency, whereas that of essential postural tremor reduced when tremor frequency departed from median values. Based on these results we conclude that

  15. Tremor revisited: treatment of PD tremor.

    Science.gov (United States)

    Jiménez, Mayté Castro; Vingerhoets, Francois J G

    2012-01-01

    Parkinsonian tremor is among the most emblematic medical signs and is one of the cardinal manifestations of Parkinson's disease (PD). Its semiology has been extensively addressed by ancient and contemporary medical literature, but more attention has been dedicated to its medical treatment in the past than nowadays. Among the hundreds of studies performed to determine the value of medical and surgical approaches on motor and non motor signs of PD, only a minority specifically considered effect on tremor as an efficacy outcome. Current available guidelines for PD treatment include attempts to specifically address tremor treatment but stress the low level of evidences available. In these conditions, with its still poorly understood pathophysiological basis and variable clinical expression PD tremor treatment is a clinical challenge. Only surgery (lesion or high frequency stimulation) of discrete deep brain targets consistently provides symptomatic long lasting alleviation. Through revision of contemporary scientific evidence, the purpose of this paper is to offer a systematic pragmatic approach to symptomatic management of tremor as one of the distinctive signs of PD that may generate substantial disability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Backprojection of volcanic tremor

    Science.gov (United States)

    Haney, Matthew M.

    2014-01-01

    Backprojection has become a powerful tool for imaging the rupture process of global earthquakes. We demonstrate the ability of backprojection to illuminate and track volcanic sources as well. We apply the method to the seismic network from Okmok Volcano, Alaska, at the time of an escalation in tremor during the 2008 eruption. Although we are able to focus the wavefield close to the location of the active cone, the network array response lacks sufficient resolution to reveal kilometer-scale changes in tremor location. By deconvolving the response in successive backprojection images, we enhance resolution and find that the tremor source moved toward an intracaldera lake prior to its escalation. The increased tremor therefore resulted from magma-water interaction, in agreement with the overall phreatomagmatic character of the eruption. Imaging of eruption tremor shows that time reversal methods, such as backprojection, can provide new insights into the temporal evolution of volcanic sources.

  17. Familial Aggregation of Cranial Tremor in Familial Essential Tremor

    Science.gov (United States)

    Louis, Elan D.; Hernandez, Nora; Clark, Lorraine N.; Ottman, Ruth

    2013-01-01

    Background Essential tremor (ET) is often familial and phenotypic features may be shared within families. Cranial (neck, voice, jaw) tremor is an important feature of ET. We examined whether cranial tremor aggregates in ET families, after controlling for other factors (age, tremor severity and duration). Methods Among ET probands and relatives enrolled in a genetic study at Columbia University (95 subjects in 28 families), we assessed the degree to which occurrence of cranial tremor in the proband predicted occurrence of cranial tremor in affected relatives. Results Forty-five (47.4%) subjects had cranial tremor on neurological examination (probands 66.7%, relatives 39.7%). Among 28 families, 23 (82.1%) contained individuals with and individuals without cranial tremor, indicating a high degree of within-family heterogeneity. In comparison to subjects without cranial tremor, those with cranial tremor had higher total tremor scores (ptremor of longer duration (p=0.01). In logistic regression models, the odds of cranial tremor in a relative was not related to occurrence of cranial tremor in the proband (p>0.24). Conclusions Cranial tremor did not aggregate in families with ET; the major predictor of this disease feature was tremor severity rather than presence of cranial tremor in another family member. PMID:23712245

  18. Fundamental Principles of Tremor Propagation in the Upper Limb.

    Science.gov (United States)

    Davidson, Andrew D; Charles, Steven K

    2017-04-01

    Although tremor is the most common movement disorder, there exist few effective tremor-suppressing devices, in part because the characteristics of tremor throughout the upper limb are unknown. To clarify, optimally suppressing tremor requires a knowledge of the mechanical origin, propagation, and distribution of tremor throughout the upper limb. Here we present the first systematic investigation of how tremor propagates between the shoulder, elbow, forearm, and wrist. We simulated tremor propagation using a linear, time-invariant, lumped-parameter model relating joint torques and the resulting joint displacements. The model focused on the seven main degrees of freedom from the shoulder to the wrist and included coupled joint inertia, damping, and stiffness. We deliberately implemented a simple model to focus first on the most basic effects. Simulating tremorogenic joint torque as a sinusoidal input, we used the model to establish fundamental principles describing how input parameters (torque location and frequency) and joint impedance (inertia, damping, and stiffness) affect tremor propagation. We expect that the methods and principles presented here will serve as the groundwork for future refining studies to understand the origin, propagation, and distribution of tremor throughout the upper limb in order to enable the future development of optimal tremor-suppressing devices.

  19. Simulation of Complex Tremor Migration Patterns

    Science.gov (United States)

    Luo, Y.; Ampuero, J. P.

    2012-12-01

    brittle asperities is relatively high and with a high contrast of friction properties comparing with the background, these asperities also play important roles affecting the macroscopic behavior of the background Slow Slip Event, including its propagation velocity, process zone size, recurrence time and moment release. Our model also successfully reproduces the characteristic spatio-temporal distribution of tremors along-dip (more frequent/ shorter recurrence time of tremor bursts at deeper part of the seismic/aseismic transition zone).

  20. Multiple Resting-State Networks Are Associated With Tremors and Cognitive Features in Essential Tremor.

    Science.gov (United States)

    Fang, Weidong; Chen, Huiyue; Wang, Hansheng; Zhang, Han; Liu, Mengqi; Puneet, Munankami; Lv, Fajin; Cheng, Oumei; Wang, Xuefeng; Lu, Xiurong; Luo, Tianyou

    2015-12-01

    The heterogeneous clinical features of essential tremor indicate that the dysfunctions of this syndrome are not confined to motor networks, but extend to nonmotor networks. Currently, these neural network dysfunctions in essential tremor remain unclear. In this study, independent component analysis of resting-state functional MRI was used to study these neural network mechanisms. Thirty-five essential tremor patients and 35 matched healthy controls with clinical and neuropsychological tests were included, and eight resting-state networks were identified. After considering the structure and head-motion factors and testing the reliability of the selected resting-state networks, we assessed the functional connectivity changes within or between resting-state networks. Finally, image-behavior correlation analysis was performed. Compared to healthy controls, essential tremor patients displayed increased functional connectivity in the sensorimotor and salience networks and decreased functional connectivity in the cerebellum network. Additionally, increased functional network connectivity was observed between anterior and posterior default mode networks, and a decreased functional network connectivity was noted between the cerebellum network and the sensorimotor and posterior default mode networks. Importantly, the functional connectivity changes within and between these resting-state networks were correlated with the tremor severity and total cognitive scores of essential tremor patients. The findings of this study provide the first evidence that functional connectivity changes within and between multiple resting-state networks are associated with tremors and cognitive features of essential tremor, and this work demonstrates a potential approach for identifying the underlying neural network mechanisms of this syndrome. © 2015 International Parkinson and Movement Disorder Society.

  1. Social Anxiety, Tremor Severity, and Tremor Disability: A Search for Clinically Relevant Measures

    OpenAIRE

    Lundervold, Duane A.; Ament, Patrick A.; Peter Holt

    2013-01-01

    Background. While social anxiety has been reported among essential tremor (ET) patients, very little is known about the relation between self-report measures of social anxiety, tremor severity and disability, and cognition. Methods. Sixty-three individuals diagnosed with ET took part in a comprehensive study examining neurocognition and behavioral functioning. A psychiatric diagnostic interview, three social anxiety questionnaires, and an idiographic-based behavioral assessment to pinpoint a...

  2. Tremor - self-care

    Science.gov (United States)

    ... habits if you have problems sleeping. Stress and anxiety can also make your tremor worse. These things may lower your stress level: Meditation, deep relaxation, or breathing exercises Reducing your caffeine intake Alcohol use can also cause ...

  3. Children with Essential Tremor

    Science.gov (United States)

    ... can become a test of will, ingenuity, and stamina. The normal challenges of growing up are magnified ... require staying inside the lines or tracing. Team sports, physical education. Some students with essential tremor have ...

  4. Pharmacotherapy of Essential Tremor

    Science.gov (United States)

    Hedera, Peter; Cibulčík, František; Davis, Thomas L.

    2013-01-01

    Essential tremor (ET) is a common movement disorder but its pathogenesis remains poorly understood. This has limited the development of effective pharmacotherapy. The current therapeutic armamentaria for ET represent the product of careful clinical observation rather than targeted molecular modeling. Here we review their pharmacokinetics, metabolism, dosing, and adverse effect profiles and propose a treatment algorithm. We also discuss the concept of medically refractory tremor, as therapeutic trials should be limited unless invasive therapy is contraindicated or not desired by patients. PMID:24385718

  5. Development of the two-part pattern during regeneration of the head in hydra

    DEFF Research Database (Denmark)

    Bode, Matthias; Awad, T A; Koizumi, O

    1988-01-01

    The head of a hydra is composed of two parts, a domed hypostome with a mouth at the top and a ring of tentacles below. When animals are decapitated a new head regenerates. During the process of regeneration the apical tip passes through a transient stage in which it exhibits tentacle-like charact......The head of a hydra is composed of two parts, a domed hypostome with a mouth at the top and a ring of tentacles below. When animals are decapitated a new head regenerates. During the process of regeneration the apical tip passes through a transient stage in which it exhibits tentacle......-Phe-amide (RFamide), which in the head of hydra is specific to the sensory cells of the hypostomal apex and the ganglion cells of the lower hypostome and tentacles. The TS-19 expression and the ganglion cells with RFamide-like immunoreactivity (RLI) arose first at the apex and spread radially. Once the tentacles...

  6. The pathophysiology of essential tremor and Parkinson's tremor

    NARCIS (Netherlands)

    Helmich, R.C.G.; Toni, I.; Deuschl, G.; Bloem, B.R.

    2013-01-01

    We review recent evidence about the pathophysiology of essential tremor and tremor in Parkinson's disease. We believe that a network perspective is necessary to understand this common neurological symptom, and that knowledge of cerebral network dysfunction in tremor disorders will help to develop

  7. The Pathophysiology of Essential Tremor and Parkinson's Tremor

    NARCIS (Netherlands)

    Helmich, R.C.G.; Toni, I.; Deuschl, G.; Bloem, B.R.

    2013-01-01

    We review recent evidence about the pathophysiology of essential tremor and tremor in Parkinson's disease. We believe that a network perspective is necessary to understand this common neurological symptom, and that knowledge of cerebral network dysfunction in tremor disorders will help to develop

  8. Coherence analysis differentiates between cortical myoclonic tremor and essential tremor

    NARCIS (Netherlands)

    van Rootselaar, AF; Maurits, NM; Koelman, JHTM; van der Hoeven, JH; Bour, LJ; Leenders, KL; Brown, P; Tijssen, MAJ

    Familial cortical myoclonic tremor with epilepsy (FCMTE) is characterized by a distal kinetic tremor, infrequent epileptic attacks, and autosomal dominant inheritance. The tremor is thought to originate from the motor cortex. In our patient group, a premovement cortical spike Could not be

  9. Overview of essential tremor

    Directory of Open Access Journals (Sweden)

    Theresa A Zesiewicz

    2010-07-01

    Full Text Available Theresa A Zesiewicz, Abinaya Chari, Israt Jahan, Amber M Miller, Kelly L SullivanDepartment of Neurology, Parkinson Research Foundation, James A. Haley Veterans Administration Hospital,University of South Florida, Tampa, FL, USAAbstract: Essential tremor (ET is one of the most common movement disorders in the world. Despite this, only one medication (propranolol is approved by the Food and Drug Administration (FDA to treat it. Fortunately, recent studies have identified some additional medications as treatment of ET. Surgical procedures, such as deep brain stimulation of the ventral intermediate nucleus of the thalamus, offer treatment for refractory tremor. The epidemiology, pathogenesis, and medical and surgical treatment of ET will be discussed in this paper.Keywords: Essential tremor, diagnosis, treatment, pathogenesis

  10. Episodic tremor and slip in Northern Sumatra subduction zone

    Science.gov (United States)

    Sianipar, Dimas; Subakti, Hendri

    2017-07-01

    The first reported observation of non-volcanic tremor in Sunda Arc in Sumbawa, Indonesia open a possibility of discovery of episodic tremor and slip (ETS) from out of Pacific Rim. Non-volcanic tremor gives some important information about dynamic of plate boundaries. The characteristics of these tremors are visually as non-impulsive, high frequency, long-duration and low-amplitude signals. Tectonic tremor occurred in a transition part of brittle-ductile of a fault and frequently associated with the shearing mechanism of slow slip. Tectonic tremor is a seismic case that also very interested, because it shows strong sensitivity to stress changes. Deep non-volcanic tremor is usually associated with episodic slow-slip events. Tectonic tremor is found in close association with geodetically observed slow-slip events (SSE) in subduction zones. One research found that there is possibility of SSE occurrence on Banyak Islands, North Sumatra revealed from coral observation. The SSE occurred on the Banyak Islands portion of the megathrust at 30-55 km depth, within the downdip transition zone. We do a systematic search of episodic tremor and its possible relationship with slow-slip phenomena in Northern Sumatra subduction zone. The spectrogram analysis is done to analyze the potential tremor signals. We use three component broadband seismic stations with 20, 25, and 50 sampling per second (BH* and SH* channels). We apply a butterworth 5 Hz highpass filter to separate the signal as local tremor and teleseismic/regional earthquakes. Before computing spectrogram to avoid high-frequency artifacts to remote triggering, we apply a 0.5 Hz filter. We also convert the binary seismic data into sound waves to make sure that these events meet the tectonic tremor criterion. We successfully examine 3 seismic stations with good recording i.e. GSI, SNSI and KCSI. We find there are many evidences of high frequency episodic tremor like signals. This include an analysis of potential triggered

  11. Exploring dielectric elastomers as actuators for hand tremor suppression

    Science.gov (United States)

    Kelley, Christopher R.; Kauffman, Jeffrey L.

    2017-04-01

    Pathological tremor results in undesired motion of body parts, with the greatest effect typically occurring in the hands. Since common treatment methods are ineffective in some patients or have risks associated with surgery or side effects, researchers are investigating mechanical means of tremor suppression. This work explores the viability of dielectric elastomers as the actuators in a tremor suppression control system. Dielectric elastomers have many properties similar to human muscle, making them a natural fit for integration into the human biomechanical system. This investigation develops a model of the integrated wrist-actuator system to determine actuator parameters that produce the necessary control authority without significantly affecting voluntary motion. Furthermore, this paper develops a control law for the actuator voltage to increase the effective viscous damping of the system. Simulations show excellent theoretical tremor suppression, demonstrating the potential for dielectric elastomers to suppress tremor while maximizing compatibility between the actuator and the human body.

  12. Action Tremor of the Legs in Essential Tremor

    Science.gov (United States)

    Poston, Kathleen L.; Rios, Eileen; Louis, Elan D.

    2009-01-01

    The hallmark feature of essential tremor (ET) is action tremor of the arms. Leg tremor may also occur yet it has not been the central focus of previous study. Its prevalence has only rarely been reported and its clinical correlates have yet to be explored. Our aims were to report the prevalence and analyze the clinical correlates of leg action tremor in patients with ET and, given the propensity for normal elderly individuals to manifest mild limb tremors, compare the prevalence with that in age-matched controls. Kinetic leg tremor rated ≥1 tremor occurred in 28/63 (44.4%) ET cases and only 9/63 (14.3%) controls (p tremor occurred in 14.3% of cases. Leg tremor severity modestly correlated with disease duration (r = 0.31, p=0.02). However, the severity and laterality of leg tremor did not correlate with that of arm tremor. The pathophysiological implications of this finding deserve further exploration. PMID:19103506

  13. An autocorrelation method to detect low frequency earthquakes within tremor

    Science.gov (United States)

    Brown, J.R.; Beroza, G.C.; Shelly, D.R.

    2008-01-01

    Recent studies have shown that deep tremor in the Nankai Trough under western Shikoku consists of a swarm of low frequency earthquakes (LFEs) that occur as slow shear slip on the down-dip extension of the primary seismogenic zone of the plate interface. The similarity of tremor in other locations suggests a similar mechanism, but the absence of cataloged low frequency earthquakes prevents a similar analysis. In this study, we develop a method for identifying LFEs within tremor. The method employs a matched-filter algorithm, similar to the technique used to infer that tremor in parts of Shikoku is comprised of LFEs; however, in this case we do not assume the origin times or locations of any LFEs a priori. We search for LFEs using the running autocorrelation of tremor waveforms for 6 Hi-Net stations in the vicinity of the tremor source. Time lags showing strong similarity in the autocorrelation represent either repeats, or near repeats, of LFEs within the tremor. We test the method on an hour of Hi-Net recordings of tremor and demonstrates that it extracts both known and previously unidentified LFEs. Once identified, we cross correlate waveforms to measure relative arrival times and locate the LFEs. The results are able to explain most of the tremor as a swarm of LFEs and the locations of newly identified events appear to fill a gap in the spatial distribution of known LFEs. This method should allow us to extend the analysis of Shelly et al. (2007a) to parts of the Nankai Trough in Shikoku that have sparse LFE coverage, and may also allow us to extend our analysis to other regions that experience deep tremor, but where LFEs have not yet been identified. Copyright 2008 by the American Geophysical Union.

  14. Tremor in multiple sclerosis

    NARCIS (Netherlands)

    Koch, Marcus; Mostert, Jop; Heersema, Dorothea; De Keyser, Jacques

    Tremor is estimated to occur in about 25 to 60 percent of patients with multiple sclerosis (MS). This symptom, which can be severely disabling and embarrassing for patients, is difficult to manage. Isoniazid in high doses, carbamazepine, propranolol and gluthetimide have been reported to provide

  15. Medical Treatment of Essential Tremor

    Science.gov (United States)

    Rajput, Ali H; Rajput, Alex

    2014-01-01

    Essential tremor (ET) is the most common pathological tremor characterized by upper limb action—postural tremor (PT)/kinetic tremor (KT). There are no specific neuropathological or biochemical abnormalities in ET. The disability is consequent to amplitude of KT, which may remain mild without handicap or may become disabling. The most effective drugs for sustained tremor control are propranolol and primidone. Symptomatic drug treatment must be individualized depending on the circumstances that provoke the tremor-related disability. Broad guidelines for treatment are discussed in this review. Patients may be treated intermittently only on stressful occasions with propranolol, clonazepam, or primidone monotherapy, or an alcoholic drink. Those with persistently disabling tremor need continued treatment. PMID:24812533

  16. Apomorphine enhances harmaline-induced tremor in rats.

    Science.gov (United States)

    Ossowska, Krystyna; Głowacka, Urszula; Kosmowska, Barbara; Wardas, Jadwiga

    2015-06-01

    Harmaline-induced tremor is a well-known model of essential tremor in humans. The aim of the present study was to examine the influence of apomorphine, a non-selective dopamine receptor agonist, on the tremor induced by harmaline in rats. Propranolol (a first-line drug in essential tremor) was used as a reference compound. Tremor, locomotor activity and focused stereotypy were measured objectively using force plate actimeters. Tremor was analyzed using a Fourier transform to generate power spectra for rhythmic behavior. The tremor induced by harmaline administered at a dose of 15 mg/kg ip was associated with an increase in power in the 9-15 Hz band (AP2) and in the tremor index, calculated as a difference between AP2 and power in the 0-8 Hz band (AP1). Propranolol injected at a dose of 20mg/kg ip reversed both of these effects of harmaline. Apomorphine administered at the doses of 0.5 and 1mg/kg sc further enhanced AP2 and at the lower dose also the tremor index elevated by harmaline. This increase in AP2 was stronger than enhancement of locomotor activity induced by apomorphine in the harmaline-treated animals. The present study suggests that the dopamine agonist apomorphine enhances the tremor induced by harmaline, and this effect is at least partly independent of hyperactivity. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. How typical are 'typical' tremor characteristics? : Sensitivity and specificity of five tremor phenomena

    NARCIS (Netherlands)

    van der Stouwe, A. M. M.; Elting, J. W.; van der Hoeven, J. H.; van Laar, T.; Leenders, K. L.; Maurits, N. M.; Tijssen, M. Aj.

    Introduction: Distinguishing between different tremor disorders can be challenging. Some tremor disorders are thought to have typical tremor characteristics: the current study aims to provide sensitivity and specificity for five 'typical' tremor phenomena. Methods: Retrospectively, we examined 210

  18. Deep Brain Stimulation for Tremor: Is There a Common Structure?

    Science.gov (United States)

    Fiechter, Michael; Nowacki, Andreas; Oertel, Markus F; Fichtner, Jens; Debove, Ines; Lachenmayer, M Lenard; Wiest, Roland; Bassetti, Claudio L; Raabe, Andreas; Kaelin-Lang, Alain; Schüpbach, Michael W; Pollo, Claudio

    2017-01-01

    Subthalamic nucleus (STN) stimulation has been recognized to control resting tremor in Parkinson disease. Similarly, thalamic stimulation (ventral intermediate nucleus; VIM) has shown tremor control in Parkinson disease, essential, and intention tremors. Recently, stimulation of the posterior subthalamic area (PSA) has been associated with excellent tremor control. Thus, the optimal site of stimulation may be located in the surrounding white matter. The objective of this work was to investigate the area of stimulation by determining the contact location correlated with the best tremor control in STN/VIM patients. The mean stimulation site and related volume of tissue activated (VTA) of 25 tremor patients (STN or VIM) were projected on the Morel atlas and compared to stimulation sites from other tremor studies. All patients showed a VTA that covered ≥50% of the area superior and medial to the STN or inferior to the VIM. Our stimulation areas suggest involvement of the more lateral and superior part of the dentato-rubro-thalamic tract (DRTT), whereas targets described in other studies seem to involve the DRTT in its more medial and inferior part when it crosses the PSA. According to anatomical and diffusion tensor imaging data, the DRTT might be the common structure stimulated at different portions within the PSA/caudal zona incerta. © 2017 S. Karger AG, Basel.

  19. Shallow episodic tremor near the Nankai Trough axis off southeast Mie prefecture, Japan

    Science.gov (United States)

    Annoura, Satoshi; Hashimoto, Tetsuo; Kamaya, Noriko; Katsumata, Akio

    2017-04-01

    We analyzed long-term continuous seismic records (from September 2015 to April 2016) of Dense Ocean-floor Network System for Earthquake and Tsunamis, an ocean-floor observation system deployed around the fore-arc slope of the Nankai subduction zone to investigate shallow tremor near the trough axis. We found that the activity of shallow tremor was concentrated in two time periods: 6 days in October 2015 and 2 weeks in April 2016. During the episode in April 2016, migration and triggering of tremor were observed. These characteristics are similar to those of tremor in the deeper part of the subduction zone. The triggering of tremor indicates that the tremor activity is very sensitive to nearby stress perturbation in the area of this study, which is near the initiation points of past large earthquakes along the Nankai Trough. Therefore, it is very important to monitor tremor activity in this region for understanding the stress accumulation process of megathrust earthquakes.

  20. Understanding Tremor in Multiple Sclerosis: Prevalence, Pathological Anatomy, and Pharmacological and Surgical Approaches to Treatment

    Directory of Open Access Journals (Sweden)

    Andrés Labiano-Fontcuberta

    2012-09-01

    Full Text Available Background: Given that tremor is one of the most prevalent and disabling features of multiple sclerosis (MS, we will review the most significant milestones in tremor in this disease in recent years, focusing on prevalence, clinical features, anatomical basis, and treatment.Methods: Data for this review were identified by searching MEDLINE with the search terms “multiple sclerosis” and “tremor”. References were also identified from relevant articles published between January 1966 and May 2012.Results: The predominant type of MS tremor is a large-amplitude, postural, and kinetic tremor, which most commonly affects the arms, although tremor can also involve head, neck, vocal cords, and trunk. Involvement of the tongue, jaw, or palate has not been reported. Although the anatomical basis underlying tremor in MS is poorly understood, the link between the cerebellum and the MS-related tremor is supported by clinical and experimental studies. Currently available medication is often unsuccessful in most cases. Surgical treatment can be a satisfactory alternative to treat severe and disabling tremor.Discussion: Tremor in MS patients could be considered as an advanced consequence of the disease and its presence suggests a more aggressive course. MS tremor can be severe and very disabling for a small group of patients. Treatment of MS tremor remains a great challenge. Recent studies suggest that dissociating tremor from cerebellar dysfunction using selected clinical tests would be the key issue to successful surgical treatment. Understanding the pathophysiology and biochemistry of tremor production in MS may lead to new therapeutic approaches.

  1. Median Filtering Methods for Non-volcanic Tremor Detection

    Science.gov (United States)

    Damiao, L. G.; Nadeau, R. M.; Dreger, D. S.; Luna, B.; Zhang, H.

    2016-12-01

    Various properties of median filtering over time and space are used to address challenges posed by the Non-volcanic tremor detection problem. As part of a "Big-Data" effort to characterize the spatial and temporal distribution of ambient tremor throughout the Northern San Andreas Fault system, continuous seismic data from multiple seismic networks with contrasting operational characteristics and distributed over a variety of regions are being used. Automated median filtering methods that are flexible enough to work consistently with these data are required. Tremor is characterized by a low-amplitude, long-duration signal-train whose shape is coherent at multiple stations distributed over a large area. There are no consistent phase arrivals or mechanisms in a given tremor's signal and even the durations and shapes among different tremors vary considerably. A myriad of masquerading noise, anthropogenic and natural-event signals must also be discriminated in order to obtain accurate tremor detections. We present here results of the median methods applied to data from four regions of the San Andreas Fault system in northern California (Geysers Geothermal Field, Napa, Bitterwater and Parkfield) to illustrate the ability of the methods to detect tremor under diverse conditions.

  2. Tremor in the elderly: Essential and aging-related tremor.

    Science.gov (United States)

    Deuschl, Günther; Petersen, Inge; Lorenz, Delia; Christensen, Kaare

    2015-09-01

    Isolated tremor in the elderly is commonly diagnosed as essential tremor (ET). The prevalence of tremor increases steeply with increasing age, whereas hereditary tremor is becoming less common. Moreover, late-manifesting tremor seems to be associated with dementia and earlier mortality. We hypothesize that different entities underlie tremor in the elderly. Two thousand four hundred forty-eight subjects from the Longitudinal Study of Aging Danish Twins older than 70 y answered screening questions for ET in 2001. Two thousand fifty-six (84%) participants drew Archimedes spirals to measure their tremor severity, and classical aging phenotypes were assessed. A subgroup of 276 individuals fulfilling either screening criteria for ET or being controls were personally assessed. Medications and mortality data are available. The spiral score increased with age. The spiral score correlated with tremor severity. For the whole cohort, mortality was significantly correlated with the spiral score, and higher spiral scores were associated with lower physical and cognitive functioning. Multivariate analysis identified higher spiral scores as an independent risk factor for mortality. In contrast, the ET patients did not show an increased but rather a lower mortality rate although it was not statistically significant. Consistent with a slower than normal aging, they were also physically and cognitively better functioning than controls. Because incident tremors beyond 70 y of age show worse aging parameters and mortality than controls and ET, we propose to label it 'aging-related tremor' (ART). This tremor starts later in life and is accompanied by subtle signs of aging both cognitively and physically. More detailed clinical features and pathogenesis warrant further assessment. © 2015 International Parkinson and Movement Disorder Society.

  3. Thalamic physiology of intentional essential tremor is more like cerebellar tremor than postural essential tremor

    OpenAIRE

    Zakaria, R; Lenz, FA; Hua, S; Avin, BH; Liu, CC; Mari, Z

    2013-01-01

    The neuronal physiological correlates of clinical heterogeneity in human essential tremor are unknown. We now test the hypothesis that thalamic neuronal and EMG activities during intention essential tremor are similar to those of the intention tremor which is characteristic of cerebellar lesions. Thalamic neuronal firing was studied in a cerebellar relay nucleus (ventral intermediate, Vim) and in a pallidal relay nucleus (ventral oral posterior, Vop) during stereotactic surgery for the treatm...

  4. Dystonia Associated with Idiopathic Slow Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Christopher Kobylecki

    2016-02-01

    Full Text Available Background: We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor.Case Report: The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4–8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor.Discussion: Slow orthostatic tremor may be associated with dystonia and dystonic tremor.

  5. Tremor in the Elderly: Essential and Aging-Related Tremor

    Science.gov (United States)

    Deuschl, Günthe; Petersen, Inge; Lorenz, Delia; Christensen, Kaare

    2016-01-01

    Isolated tremor in the elderly is commonly diagnosed as essential tremor (ET). The prevalence of tremor increases steeply with increasing age, whereas hereditary tremor is becoming less common. Moreover, late-manifesting tremor seems to be associated with dementia and earlier mortality. We hypothesize that different entities underlie tremor in the elderly. Two thousand four hundred forty-eight subjects from the Longitudinal Study of Aging Danish Twins older than 70 y answered screening questions for ET in 2001. Two thousan fifty-six (84%) participants drew Archimedes spirals to measure their tremor severity, and classical aging phenotypes were assessed. A subgroup of 276 individuals fulfilling either screening criteria for ET or being controls were personally assessed. Medications and mortality data are available. The spiral score increased with age. The spiral score correlated with tremor severity. For the whole cohort, mortality was significantly correlated with the spiral score, and higher spiral scores were associated with lower physical and cognitive functioning. Multivariate analysis identified higher spiral scores as an independent risk factor for mortality. In contrast, the ET patients did not show an increased but rather a lower mortality rate although it was not statistically significant. Consistent with a slower than normal aging, they were also physically and cognitively better functioning than controls. Because incident tremors beyond 70 y of age show worse aging parameters and mortality than controls and ET, we propose to label it ‘aging-related tremor’ (ART). This tremor starts later in life and is accompanied by subtle signs of aging both cognitively and physically. More detailed clinical features and pathogenesis warrant further assessment. PMID:26095699

  6. Pregabalin for essential tremor.

    Science.gov (United States)

    Bruno, Elisa; Nicoletti, Alessandra; Quattrocchi, Graziella; Filippini, Graziella; Colosimo, Carlo; Zappia, Mario

    2016-10-20

    Essential tremor is one of the most common movement disorders. Treatment primarily consists of pharmacological agents. While primidone and propranolol are well-established treatments in clinical practice, they may be ineffective in 25% to 55% of patients and can produce serious adverse events in a large percentage of them. For these reasons, it is worth evaluating the treatment alternatives for essential tremor. Some specialists have suggested that pregabalin could be a potentially useful agent, but there is uncertainty about its efficacy and safety. To assess the effects of pregabalin versus placebo or other treatment for essential tremor in adults. We performed a systematic search without language restrictions to identify all relevant trials up to December 2015. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, NICE, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform (ICTRP). We handsearched grey literature and examined the reference lists of identified studies and reviews. We included all randomised controlled trials (RCTs) of pregabalin versus placebo or any other treatments. We included studies in which the diagnosis of ET was made according to accepted and validated diagnostic criteria. We excluded studies conducted in patients presenting secondary forms of tremor or reporting only neurophysiological parameters to assess outcomes. Two reviewers independently collected and extracted data using a data collection form. We assessed the risk of bias of the body of evidence, and we used inverse variance methods to analyse continuous outcomes and measurement scales. We compared the mean difference between treatment groups, and we combined results for dichotomous outcomes using Mantel-Haenszel methods and risk differences We used Review Manager software for data management and analysis. We only found one study eligible for this review (22 participants). We assessed the risk of

  7. Parts : valitsus ei saa kukkuda heade kavatsuste pärast / Juhan Parts ; interv. Rasmus Kagge

    Index Scriptorium Estoniae

    Parts, Juhan, 1966-

    2005-01-01

    Ilmunud ka: Pärnu Postimees 16. märts, lk. 7. Peaminister Juhan Parts selgitab olukorda valitsuses, võimalikust umbusalduse avaldamisest justiitsminister Ken-Marti Vaherile, võimuliidu püsimajäämise tingimustest

  8. Voluntary driven elbow orthosis with speed controlled tremor suppression

    Directory of Open Access Journals (Sweden)

    Gil eHerrnstadt

    2016-03-01

    Full Text Available Robotic technology is gradually becoming commonplace in the medical sector and in the service of patients. Medical conditions that have benefited from significant technological development include stroke, for which rehabilitation with robotic devices is administered, and surgery assisted by robots. Robotic devices have also been proposed for assistance of movement disorders. Pathological tremor, among the most common movement disorders, is such one example. In practice, the dissemination and availability of tremor suppression robotic systems has been limited. Devices in the marketplace tend to either be non-ambulatory or to target specific functions such as eating and drinking.We have developed a one degree-of-freedom (DOF elbow orthosis that could be worn by an individual with tremor. A speed controlled voluntary driven suppression approach is implemented with the orthosis. Typically tremor suppression methods estimate the tremor component of the signal and produce a canceling counterpart signal. The suggested approach, instead estimates the voluntary component of the motion. A controller then actuates the orthosis based on the voluntary signal while simultaneously rejecting the tremorous motion.In this work, we tested the suppressive orthosis using a 1 DOF robotic system that simulates the human arm. The suggested suppression approach does not require a model of the human arm. Moreover, the human input along with the orthosis forearm gravitational forces, of nonlinear nature, are considered as part of the disturbance to the suppression system. Therefore, the suppression system can be modeled linearly. Nevertheless, the orthosis forearm gravitational forces can be compensated by the suppression system.The electromechanical design of the orthosis is presented, and data from an Essential Tremor patient is used as the human input. Velocity tracking results demonstrate an RMS error of 0.31 rad/s, and a power spectral density shows a reduction of

  9. Brain SPECT can differentiate between essential tremor and early-stage tremor-dominant Parkinson's disease.

    Science.gov (United States)

    Song, In-Uk; Park, Jeong-Wook; Chung, Sung-Woo; Chung, Yong-An

    2014-09-01

    There are no confirmatory or diagnostic tests or tools to differentiate between essential tremor (ET) and tremor in idiopathic Parkinson's disease (PD). Although a number of imaging studies have indicated that there are differences between ET and PD, the functional imaging study findings are controversial. Therefore, we analyzed regional cerebral blood flow (CBF) by perfusion brain single-photon emission computed tomography (SPECT) to identify differences between ET and tremor-dominant Parkinson's disease (TPD). We recruited 33 patients with TPD, 16 patients with ET, and 33 healthy controls. We compared the severity of tremor symptoms by comparing the Fahn-Tolosa-Marin rating scale (FTM) score and the tremor score from Unified Parkinson's Disease Rating Scale (UPDRS) between TPD and ET patients. Subjects were evaluated by neuropsychological assessments, MRI and perfusion SPECT of the brain. Total FTM score was significantly higher in ET patients than TPD patients. However, there was no significant difference in FTM Part A scores between the two patient groups, while the scores for FTM Part B and C were significantly higher in ET patients than TPD patients. Brain SPECT analysis of the TPD group demonstrated significant hypoperfusion of both the lentiform nucleus and thalamus compared to the ET group. Brain perfusion SPECT may be a useful clinical method to differentiate between TPD and ET even during early-phase PD, because the lentiform nucleus and thalamus show differences in regional perfusion between these two groups during this time period. Additionally, we found evidence of cerebellar dysfunction in both TPT and ET. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Alprazolam for essential tremor.

    Science.gov (United States)

    Bruno, Elisa; Nicoletti, Alessandra; Quattrocchi, Graziella; Filippini, Graziella; Zappia, Mario; Colosimo, Carlo

    2015-12-06

    Essential tremor (ET) is one of the most common movement disorders. Treatment is based primarily on pharmacological agents. On this basis, although primidone and propranolol are well-established treatments in clinical practice, they could be ineffective in 25% to 55% of patients and can produce serious adverse events (AEs) in a large percentage of individuals. For these reasons, evaluating treatment alternatives for ET may be a worthwhile pursuit. Alprazolam has been suggested as a potentially useful agent for treatment of individuals with ET, but its efficacy and safety are uncertain. PrimaryTo assess the efficacy and safety of alprazolam in the treatment of individuals with ET. SecondaryTo examine effects of alprazolam treatment on the quality of life of people with ET. We carried out a systematic search without language restrictions to identify all relevant trials. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (January 1966 to September 2015), EMBASE (January 1988 to September 2015), the National Institute for Health and Care Excellence (NICE) (1999 to September 2015), ClinicalTrials.gov (1997 to September 2015) and the World Health Organiza tion (WHO) International Clinical Trials Registry Platform (ICTRP) (2004 to September 2015). We handsearched grey literature and examined the reference lists of identified studies and reviews. We included all randomised controlled trials (RCTs) of alprazolam versus placebo or any other treatment. We included studies in which ET was diagnosed according to accepted and validated diagnostic criteria. We excluded studies that included patients presenting with secondary forms of tremor or reporting only neurophysiological parameters for the pur p ose of assessing outcomes. Two review authors independently collected and extracted data using a data collection form. We assessed risk of bias and the body of evidence. We used inverse variance methods for continuous outcomes and measurement scales

  11. Treatment of essential tremor with arotinolol.

    Science.gov (United States)

    Kuroda, Y; Kakigi, R; Shibasaki, H

    1988-04-01

    We investigated the effect of arotinolol, a new peripherally acting beta-adrenergic blocker, in 15 patients with essential tremor. The patients received 30 mg per day of arotinolol for 8 weeks. Accelerometer readings showed a significant reduction in amplitude of postural tremor after treatment. Action tremor also improved to essentially the same degree as postural tremor. The present findings support the view that the therapeutic effect of beta-blockers in essential tremor is mediated by peripheral beta-adrenergic receptors.

  12. Clinical Classification of Borderline Cases in the Family Study of Essential Tremor: An Analysis of Phenotypic Features

    Directory of Open Access Journals (Sweden)

    Elan D. Louis

    2014-02-01

    Full Text Available Background: In genetic research on essential tremor (ET, certain individuals may be particularly challenging to categorize diagnostically.Methods: In the Family Study of Essential Tremor (>200 enrollees, 28 participants with borderline clinical findings who did not meet strict criteria for ET were assigned final diagnoses of ET. We scrutinized the clinical features of these cases and the sensitivity/specificity of certain features that best separated them from 19 unaffected individuals. Results: Borderline ET cases differed from unaffected individuals in eight features: total tremor score, at least one kinetic tremor rating ≥1.5, at least one kinetic tremor rating ≥1.5 in the dominant arm, tremor rating during spiral drawing ≥1.5, higher spiral axis score, head tremor, complaint of tremor, and comment on tremor by others. The combination of at least one kinetic tremor rating ≥1.5 in the dominant arm and the presence of at least three of the remaining seven features predicted the clinician‐assigned diagnosis in 88.6% of borderline ET vs. unaffected individuals (sensitivity 84.6%, specificity 94.4%.Discussion: In a family study, a small number of clinical features characterized borderline ET, and a particular combination of these separated the majority of these borderline cases from normals. These analyses may help researchers minimize diagnostic misclassification.

  13. Intermittent cortical involvement in the preservation of tremor in essential tremor

    NARCIS (Netherlands)

    Sharifi, Sarvi; Luft, Frauke; Verhagen, Rens; Heida, Tjitske; Speelman, Johannes D.; Bour, Lo J.; van Rootselaar, Anne-Fleur

    2017-01-01

    Cortical involvement in essential tremor, an involuntary action tremor supposedly of subcortical origin, is uncertain. Conflicting results of corticomuscular coherence studies in essential tremor suggest an intermittent corticomuscular coupling. On the basis of the literature, we hypothesized that

  14. Role of altered cerebello-thalamo-cortical network in the neurobiology of essential tremor

    Energy Technology Data Exchange (ETDEWEB)

    Lenka, Abhishek; Bhalsing, Ketaki Swapnil; Jhunjhunwala, Ketan [National Institute of Mental Health and Neurosciences, Department of Neurology, Bangalore, Karnataka (India); National Institute of Mental Health and Neurosciences, Department of Clinical Neurosciences, Bangalore, Karnataka (India); Panda, Rajanikant; Saini, Jitender; Bharath, Rose Dawn [National Institute of Mental Health and Neurosciences, Department of Neuroimaging and Interventional Radiology, Bangalore, Karnataka (India); Naduthota, Rajini M.; Yadav, Ravi; Pal, Pramod Kumar [National Institute of Mental Health and Neurosciences, Department of Neurology, Bangalore, Karnataka (India)

    2017-02-15

    Essential tremor (ET) is the most common movement disorder among adults. Although ET has been recognized as a mono-symptomatic benign illness, reports of non-motor symptoms and non-tremor motor symptoms have increased its clinical heterogeneity. The neural correlates of ET are not clearly understood. The aim of this study was to understand the neurobiology of ET using resting state fMRI. Resting state functional MR images of 30 patients with ET and 30 age- and gender-matched healthy controls were obtained. The functional connectivity of the two groups was compared using whole-brain seed-to-voxel-based analysis. The ET group had decreased connectivity of several cortical regions especially of the primary motor cortex and the primary somatosensory cortex with several right cerebellar lobules compared to the controls. The thalamus on both hemispheres had increased connectivity with multiple posterior cerebellar lobules and vermis. Connectivity of several right cerebellar seeds with the cortical and thalamic seeds had significant correlation with an overall score of Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) as well as the subscores for head tremor and limb tremor. Seed-to-voxel resting state connectivity analysis revealed significant alterations in the cerebello-thalamo-cortical network in patients with ET. These alterations correlated with the overall FTM scores as well as the subscores for limb tremor and head tremor in patients with ET. These results further support the previous evidence of cerebellar pathology in ET. (orig.)

  15. Re-Emergent Tremor of Parkinson's Disease Masquerading as Essential Tremor

    Directory of Open Access Journals (Sweden)

    Sarah Morgan

    2016-03-01

    Full Text Available Background: The re-emergent tremor of Parkinson’s disease (PD is generally recognized as a postural tremor. Phenomenology Shown: A PD patient with a re-emergent tremor occurring during a task (spiral drawing, which on the surface produced a tremor that resembled that of essential tremor (ET. Educational Value: Researchers and clinicians should be aware of features of this re-emergent tremor to help distinguish it from that of ET.

  16. Postural and Intention Tremors: A Detailed Clinical Study of Essential Tremor vs. Parkinson?s Disease

    OpenAIRE

    Sternberg, Eliezer J.; Alcalay, Roy N; Levy, Oren A.; Louis, Elan D.

    2013-01-01

    Background: An estimated 30–50% of essential tremor (ET) diagnoses are incorrect, and the true diagnosis in those patients is often Parkinson’s disease (PD) or other tremor disorders. There are general statements about the tremor in these ET and PD, but published data on the more subtle characteristics of tremor are surprisingly limited. Postural tremor may occur in both disorders, adding to the difficulty. There are several anecdotal impressions regarding specific features of postural tremor...

  17. Re-Emergent Tremor of Parkinson?s Disease Masquerading as Essential Tremor

    OpenAIRE

    Morgan, Sarah; Louis, Elan D.

    2016-01-01

    Background The re-emergent tremor of Parkinson?s disease (PD) is generally recognized as a postural tremor. Phenomenology Shown A PD patient with a re-emergent tremor occurring during a task (spiral drawing), which on the surface produced a tremor that resembled that of essential tremor (ET). Educational Value Researchers and clinicians should be aware of features of this re-emergent tremor to help distinguish it from that of ET.

  18. Action tremor in Parkinson's disease: frequency and relationship to motor and non-motor signs.

    Science.gov (United States)

    Gigante, A F; Bruno, G; Iliceto, G; Guido, M; Liuzzi, D; Mancino, P V; De Caro, M F; Livrea, P; Defazio, G

    2015-02-01

    Action tremor may occur in patients with Parkinson's disease and cause misdiagnosis with other movement disorders such as essential tremor and dystonia. Data on the frequency of action tremor in Parkinson's disease and on the relationships with other motor and non-motor signs are limited. A cross-sectional study of 237 patients with Parkinson's disease staging 1-2 on the Hoehn-Yahr scale was conducted. Data on action tremor and other motor and non-motor signs were collected using the Unified Parkinson's Disease Rating Scale part III and the Non-Motor Symptoms Scale. Action tremor was found in 46% of patients and was associated with both severity of rest tremor (adjusted odds ratio 3.0, P Hoehn-Yahr scale. Action tremor correlates with rest tremor and rigidity and may be associated with a lower burden of non-motor symptoms. These findings suggest a contribution of non-dopaminergic mechanisms to action tremor pathophysiology. © 2014 EAN.

  19. Slip rate and tremor genesis in Cascadia

    Science.gov (United States)

    Wech, Aaron G.; Bartlow, Noel M.

    2014-01-01

    At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

  20. Postural tremor and chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Cao, Yiming; Menon, Parvathi; Ching-Fen Chang, Florence; Mahant, Neil; Geevasinga, Nimeshan; Fung, Victor S C; Vucic, Steve

    2017-03-01

    Chronic inflammatory demyelinating polyneuropathy (CIDP) typically presents with a combination of sensory and motor impairments. Tremor is recognized as a common and debilitating feature in CIDP, although the underlying mechanisms are unclear. Clinical tremor severity and disability scores were collected prospectively in 25 CIDP patients and compared with 22 neuromuscular controls. Postural and kinetic tremor were significantly more frequent in CIDP patients (80%) than in neuromuscular controls (35%; P Tremor severity and tremor-related disability were also significantly greater in CIDP patients than in controls. Accelerometry data confirmed the presence of a 5.5 Hz postural tremor and a 5 Hz kinetic tremor. Tremor appears to be a common clinical feature of CIDP that results in significant disability. Sensory and motor impairment may be associated with development of tremor in CIDP. Muscle Nerve 55: 338-343, 2017. © 2016 Wiley Periodicals, Inc.

  1. Tremor: Clinical Phenomenology and Assessment Techniques

    Science.gov (United States)

    Hess, Christopher W.; Pullman, Seth L.

    2012-01-01

    Background Tremors are among the most common movement disorders. As there can be considerable variability in the manner in which clinicians assess tremor, objective quantitative tools such as electromyography, accelerometry, and computerized, spiral analysis can be very useful in establishing a clinical diagnosis and in research settings. Methods In this review, we discuss the various methods of quantitative tremor analysis and the classification and pathogenesis of tremor. The most common pathologic tremors and an approach to the diagnosis of tremor etiology are described. Conclusions Pathologic tremors are common, and the diagnosis of underlying etiology is not always straightforward. Computerized quantitative tremor analysis is a valuable adjunct to careful clinical evaluation in distinguishing tremulous diseases from physiologic tremors, and can also help shed light on their pathogenesis. PMID:23439931

  2. Postural and intention tremors: Detailed clinical study of essential tremor vs. Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Eliezer J Sternberg

    2013-05-01

    Full Text Available ABSTRACTBackground: An estimated 30-50% of essential tremor diagnoses are incorrect, and the true diagnosis in those patients is often Parkinson’s disease or other tremor disorders. There are general statements about the tremor in these essential tremor and Parkinson’s disease, but published data on the more subtle characteristics of tremor are surprisingly limited. Postural tremor may occur in both disorders, adding to the difficulty. There are several anecdotal impressions regarding specific features of postural tremor in essential tremor vs. Parkinson’s disease, including joint distribution (e.g., phalanges, metacarpal-phalangeal joints, wrist, tremor directionality (e.g., flexion-extension vs. pronation-supination, and presence of intention tremor. However, there is little data to support these impressions.Methods: In this cross-sectional study, 100 patients (essential tremor, 50 Parkinson’s disease underwent detailed videotaped neurological examinations. Arm tremor was rated by a movement disorder neurologist who assessed severity and directionality across multiple joints. Results: During sustained arm extension, essential tremor patients exhibited more wrist than metacarpal-phalangeal and phalangeal joint tremor than did Parkinson’s disease patients (p<0.001, and more wrist flexion-extension tremor than wrist pronation-supination tremor (p<0.001. During the finger-nose-finger maneuver, intention tremor was present in approximately one in four (28% essential tremor patients vs. virtually none (4% of the Parkinson’s patients (p<0.001.Conclusions: We evaluated the location, severity, and directionality of postural tremor in essential tremor and Parkinson’s disease, and the presence of intention tremor, observing several clinical differences. We hope that detailed phenomenological data on tremor in essential tremor and Parkinson’s disease will help practicing physicians delineate the two diseases.

  3. Phase dependent modulation of tremor amplitude in essential tremor through thalamic stimulation

    Science.gov (United States)

    Cagnan, Hayriye; Brittain, John-Stuart; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Joint, Carole; Fitzgerald, James; Green, Alexander L.; Aziz, Tipu

    2013-01-01

    High frequency deep brain stimulation of the thalamus can help ameliorate severe essential tremor. Here we explore how the efficacy, efficiency and selectivity of thalamic deep brain stimulation might be improved in this condition. We started from the hypothesis that the effects of electrical stimulation on essential tremor may be phase dependent, and that, in particular, there are tremor phases at which stimuli preferentially lead to a reduction in the amplitude of tremor. The latter could be exploited to improve deep brain stimulation, particularly if tremor suppression could be reinforced by cumulative effects. Accordingly, we stimulated 10 patients with essential tremor and thalamic electrodes, while recording tremor amplitude and phase. Stimulation near the postural tremor frequency entrained tremor. Tremor amplitude was also modulated depending on the phase at which stimulation pulses were delivered in the tremor cycle. Stimuli in one half of the tremor cycle reduced median tremor amplitude by ∼10%, while those in the opposite half of the tremor cycle increased tremor amplitude by a similar amount. At optimal phase alignment tremor suppression reached 27%. Moreover, tremor amplitude showed a non-linear increase in the degree of suppression with successive stimuli; tremor suppression was increased threefold if a stimulus was preceded by four stimuli with a similar phase relationship with respect to the tremor, suggesting cumulative, possibly plastic, effects. The present results pave the way for a stimulation system that tracks tremor phase to control when deep brain stimulation pulses are delivered to treat essential tremor. This would allow treatment effects to be maximized by focussing stimulation on the optimal phase for suppression and by ensuring that this is repeated over many cycles so as to harness cumulative effects. Such a system might potentially achieve tremor control with far less power demand and greater specificity than current high frequency

  4. Postural and Intention Tremors: A Detailed Clinical Study of Essential Tremor vs. Parkinson’s Disease

    Science.gov (United States)

    Sternberg, Eliezer J.; Alcalay, Roy N.; Levy, Oren A.; Louis, Elan D.

    2013-01-01

    Background: An estimated 30–50% of essential tremor (ET) diagnoses are incorrect, and the true diagnosis in those patients is often Parkinson’s disease (PD) or other tremor disorders. There are general statements about the tremor in these ET and PD, but published data on the more subtle characteristics of tremor are surprisingly limited. Postural tremor may occur in both disorders, adding to the difficulty. There are several anecdotal impressions regarding specific features of postural tremor in ET vs. PD, including joint distribution (e.g., phalanges, metacarpal-phalangeal joints, wrist), tremor directionality (e.g., flexion-extension vs. pronation-supination), and presence of intention tremor. However, there is little data to support these impressions. Methods: In this cross-sectional study, 100 patients (ET, 50 PD) underwent detailed videotaped neurological examinations. Arm tremor was rated by a movement disorder neurologist who assessed severity and directionality across multiple joints. Results: During sustained arm extension, ET patients exhibited more wrist than metacarpal-phalangeal and phalangeal joint tremor than did PD patients (p tremor than wrist pronation-supination tremor (p tremor was present in approximately one in four (28%) ET patients vs. virtually none (4%) of the Parkinson’s patients (p tremor in ET and PD, and the presence of intention tremor, observing several clinical differences. We hope that detailed phenomenological data on tremor in ET and PD will help practicing physicians delineate the two diseases. PMID:23717300

  5. Tremor magnitude: a single index to assess writing and drawing in essential tremor.

    Science.gov (United States)

    Ulmanová, Olga; Homann, Carl Nikolaus; Ulman, Radek; Jech, Robert; Capek, Václav; Klempír, Jirí; Růzicka, Evzen

    2007-05-01

    Hand tremor often causes disability in patients with essential tremor (ET). Aim of the study was to investigate whether tremor magnitude, a new single quantitative score obtained from digital tablet recordings of writing and drawing, is able to adequately reflect disability in ET patients. Mean tremor magnitude values showed significant difference between 14 ET patients and 14 healthy age matched controls (p<0.0001). The tremor magnitude values showed significant correlation with standard methods of clinical assessment (p<0.01). We present tremor magnitude as an index that reflects disability resulting from tremor and can help to evaluate ET.

  6. The Clinical Evaluation of Parkinson's Tremor

    NARCIS (Netherlands)

    Zach, H.; Dirkx, M.; Bloem, B.R.; Helmich, R.C.

    2015-01-01

    Parkinson's disease harbours many different tremors that differ in distribution, frequency, and context in which they occur. A good clinical tremor assessment is important for weighing up possible differential diagnoses of Parkinson's disease, but also to measure the severity of the tremor as a

  7. Pathophysiology and Management of Parkinsonian Tremor

    NARCIS (Netherlands)

    Helmich, Rick; Dirkx, M.F.M.

    2017-01-01

    Parkinson's tremor is one of the cardinal motor symptoms of Parkinson's disease. The pathophysiology of Parkinson's tremor is different from that of other motor symptoms such as bradykinesia and rigidity. In this review, the authors discuss evidence suggesting that tremor is a network disorder that

  8. Correlates Between Force and Postural Tremor in Older Individuals with Essential Tremor.

    Science.gov (United States)

    Kavanagh, Justin J; Keogh, Justin W L

    2016-12-01

    Essential tremor (ET) is commonly associated with kinetic tremor. However, other forms of tremor, such as force and postural tremor, may occur in ET with less severity. This study objectively assessed force and postural tremor characteristics in ET with the purpose of identifying the relationships between these tremors. Ten individuals with ET (age 71 ± 5 years) and ten healthy controls (age 70 ± 5 years) participated in the study. Force tremor was quantified as fluctuations in index finger abduction force during isometric contractions at 10 % maximum voluntary contraction (MVC) and 60 % MVC. Postural tremor was quantified as index finger acceleration when the subjects held their entire arm unsupported, and when their arm was supported so that only the index finger could move. Time- and frequency-domain parameters were extracted from tremor data, and then correlations within, and between, tremor subtypes were examined. ET force tremor was dependent on contraction intensity whereas postural tremor was unaffected by the level of limb support. Significant correlations existed between frequency components of postural tremor and force tremor amplitude. Force tremor amplitude normalised to the level of contraction intensity correlated to the proportion of power for postural tremor. These correlations were observed for both contraction intensities and both levels of postural support. The proportion of power represents the output of central oscillators in ET patients and therefore correlated well to force tremor. Given that significant relationships existed between spectral features of postural tremor and the overall force tremor amplitude, it is clear that these tremor modalities are not completely independent in older adults with ET.

  9. Advances in the Assessment and Suppression of Pathological Tremor in the Framework of TREMOR Project

    OpenAIRE

    Gallego, Juan Álvaro; Rocón, Eduardo; Pons Rovira, José Luis

    2013-01-01

    Pathological tremor is the most prevalent movement disorder, and is not effectively managed in a significant proportion of patients. In addition, the epidemiology and neurophysiology of tremors is yet not understood. This abstract summarizes our work on TREMOR project, which aimed at the development and validation of a wearable neuroprosthesis for tremor management. This neuroprosthesis comprised a multimodal interface to parameterize tremor during voluntary activities, and a functional elect...

  10. Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremor

    Science.gov (United States)

    Shelly, David R.

    2009-01-01

    Earthquake predictability depends, in part, on the degree to which sudden slip is preceded by slow aseismic slip. Recently, observations of deep tremor have enabled inferences of deep slow slip even when detection by other means is not possible, but these data are limited to certain areas and mostly the last decade. The region near Parkfield, California, provides a unique convergence of several years of high-quality tremor data bracketing a moderate earthquake, the 2004 magnitude 6.0 event. Here, I present detailed observations of tectonic tremor from mid-2001 through 2008 that indicate deep fault slip both before and after the Parkfield earthquake that cannot be detected with surface geodetic instruments. While there is no obvious short-term precursor, I find unidirectional tremor migration accompanied by elevated tremor rates in the 3 months prior to the earthquake, which suggests accelerated creep on the fault ∼16 km beneath the eventual earthquake hypocenter.

  11. Effects of alprazolam on cortical activity and tremors in patients with essential tremor.

    Science.gov (United States)

    Ibáñez, Jaime; González de la Aleja, Jesús; Gallego, Juan A; Romero, Juan P; Saíz-Díaz, Rosana A; Benito-León, Julián; Rocon, Eduardo

    2014-01-01

    Essential tremor (ET) is characterised by postural and action tremors with a frequency of 4-12 Hz. Previous studies suggest that the tremor activity originates in the cerebello-thalamocortical pathways. Alprazolam is a short-acting benzodiazepine that attenuates tremors in ET. The mechanisms that mediate the therapeutic action of alprazolam are unknown; however, in healthy subjects, benzodiazepines increase cortical beta activity. In this study, we investigated the effect of alprazolam both on beta and tremor-related cortical activity and on alterations in tremor presentation in ET patients. Therefore, we characterised the dynamics of tremor and cortical activity in ET patients after alprazolam intake. We recorded hand tremors and contralateral cortical activity in four recordings before and after a single dose of alprazolam. We then computed the changes in tremors, cortico-muscular coherence, and cortical activity at the tremor frequency and in the beta band. Alprazolam significantly attenuated tremors (EMG: 76.2 ± 22.68%), decreased cortical activity in the tremor frequency range and increased cortical beta activity in all patients (Palprazolam intake. We observed that the tremor severity decreased in association with an increased ratio of beta to tremor-related cortical activity. We hypothesise that the increase in cortical beta activity may act as a blocking mechanism and may dampen the pathological oscillatory activity, which in turn attenuates the observed tremor.

  12. Internal tremor in Parkinson's disease, multiple sclerosis, and essential tremor.

    Science.gov (United States)

    Cochrane, Graham D; Rizvi, Syed; Abrantes, Ana; Crabtree, Brigid; Cahill, Jonathan; Friedman, Joseph H

    2015-10-01

    Internal tremor (IT) is a poorly recognized symptom that has been described in Parkinson's disease (PD). Described as a feeling of tremor in the extremities or trunk without actual movement, ITs are not debilitating but can be bothersome to patients. The origin of the sensation is unknown., and ITs may be prevalent in other diseases than PD. The present study sought to expand knowledge about IT by confirming their presence in PD, and determining their prevalence in Multiple Sclerosis (MS), and Essential Tremor (ET). A survey was developed in order to determine the prevalence of IT in PD, MS, and ET and to learn what associations with various disease characteristics were present. The survey was administered to 89 consecutive PD, 70 MS, and 11 ET patients. ITs were found to be a prevalent symptom in all three disorders (32.6% of PD, 35.9% of MS, and 54.5% of ET subjects reported experiencing ITs). ITs were found to be associated both with the subjects' perceived levels of anxiety and the presence of visible tremors. ITs appear to be a common symptom in all three disorders studied. These results need to be confirmed and compared to appropriate control populations. Copyright © 2015. Published by Elsevier Ltd.

  13. Effects of alprazolam on cortical activity and tremors in patients with essential tremor.

    Directory of Open Access Journals (Sweden)

    Jaime Ibáñez

    Full Text Available BACKGROUND: Essential tremor (ET is characterised by postural and action tremors with a frequency of 4-12 Hz. Previous studies suggest that the tremor activity originates in the cerebello-thalamocortical pathways. Alprazolam is a short-acting benzodiazepine that attenuates tremors in ET. The mechanisms that mediate the therapeutic action of alprazolam are unknown; however, in healthy subjects, benzodiazepines increase cortical beta activity. In this study, we investigated the effect of alprazolam both on beta and tremor-related cortical activity and on alterations in tremor presentation in ET patients. Therefore, we characterised the dynamics of tremor and cortical activity in ET patients after alprazolam intake. METHODS: We recorded hand tremors and contralateral cortical activity in four recordings before and after a single dose of alprazolam. We then computed the changes in tremors, cortico-muscular coherence, and cortical activity at the tremor frequency and in the beta band. RESULTS: Alprazolam significantly attenuated tremors (EMG: 76.2 ± 22.68%, decreased cortical activity in the tremor frequency range and increased cortical beta activity in all patients (P<0.05. At the same time, the cortico-muscular coherence at the tremor frequency became non-significant (P<0.05. We also found a significant correlation (r = 0.757, P<0.001 between the reduction in tremor severity and the increased ratio of cortical activity in the beta band to the activity observed in the tremor frequency range. CONCLUSIONS: This study provides the first quantitative analysis of tremor reduction following alprazolam intake. We observed that the tremor severity decreased in association with an increased ratio of beta to tremor-related cortical activity. We hypothesise that the increase in cortical beta activity may act as a blocking mechanism and may dampen the pathological oscillatory activity, which in turn attenuates the observed tremor.

  14. Characteristics of Task-specific Tremor in String Instrument Players

    OpenAIRE

    Lee, André; Chadde, Mareike; Altenmüller, Eckart; Schoonderwaldt, Erwin

    2014-01-01

    Background In recent studies primary bowing tremor has been described; however, tremor frequency has never been quantitatively assessed. In addition to describing phenomenological aspects of tremor we thus aimed at assessing tremor frequency. Our hypothesis was that primary bowing tremor is similar to the phenomenological aspects and frequency of primary writing tremor. Methods We quantified primary bowing tremor in four violinists under two conditions: open strings and a G major scale. Data ...

  15. Determining posture from physiological tremor

    Science.gov (United States)

    Albert, Mark V.; Kording, Konrad P.

    2012-01-01

    The measurement of body and limb posture is important to many clinical and research studies. Current approaches either directly measure posture (e.g., using optical or magnetic methods) or more indirectly measure it by integrating changes over time (e.g., using gyroscopes and/or accelerometers). Here, we introduce a way of estimating posture from movements without requiring integration over time and the resultingcomplications. Weshow how the almost imperceptible tremor of the hand is affected by posture in an intuitive way and therefore can be used to estimate the posture of the arm. We recorded postures and tremor of the arms of volunteers. By using only the minor axis in the covariance of hand tremor, we could estimate the angle of the forearm with a standard deviation of about 4° when the subject's elbow is resting on a table and about 10° when it is off the table. This technique can also be applied as a post hoc analysis on other hand-position data sets to extract posture. This new method allows the estimation of body posture from tremor, is complementary to other techniques, and so can become a useful tool for future research and clinical applications. PMID:21997329

  16. Treatment of patients with essential tremor.

    Science.gov (United States)

    Deuschl, Günther; Raethjen, Jan; Hellriegel, Helge; Elble, Rodger

    2011-02-01

    Essential tremor is a common movement disorder. Tremor severity and handicap vary widely, but most patients with essential tremor do not receive a diagnosis and hence are never treated. Furthermore, many patients abandon treatment because of side-effects or poor efficacy. A newly developed algorithm, based on the logarithmic relation between tremor amplitude and clinical tremor ratings, can be used to compare the magnitude of effect of available treatments. Drugs with established efficacy (propranolol and primidone) produce a mean tremor reduction of about 50%. Deep brain stimulation (DBS) in the thalamic nucleus ventrointermedius or neighbouring subthalamic structures reduces tremor by about 90%. However, no controlled trials of DBS have been done, and the best target is still uncertain. Better drugs are needed, and controlled trials are required to determine the safety and efficacy of DBS in the nucleus ventrointermedius and neighbouring subthalamic structures. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Numerical Simulation and Validation of a High Head Model Francis Turbine at Part Load Operating Condition

    Science.gov (United States)

    Goyal, Rahul; Trivedi, Chirag; Kumar Gandhi, Bhupendra; Cervantes, Michel J.

    2017-07-01

    Hydraulic turbines are operated over an extended operating range to meet the real time electricity demand. Turbines operated at part load have flow parameters not matching the designed ones. This results in unstable flow conditions in the runner and draft tube developing low frequency and high amplitude pressure pulsations. The unsteady pressure pulsations affect the dynamic stability of the turbine and cause additional fatigue. The work presented in this paper discusses the flow field investigation of a high head model Francis turbine at part load: 50% of the rated load. Numerical simulation of the complete turbine has been performed. Unsteady pressure pulsations in the vaneless space, runner, and draft tube are investigated and validated with available experimental data. Detailed analysis of the rotor stator interaction and draft tube flow field are performed and discussed. The analysis shows the presence of a rotating vortex rope in the draft tube at the frequency of 0.3 times of the runner rotational frequency. The frequency of the vortex rope precession, which causes severe fluctuations and vibrations in the draft tube, is predicted within 3.9% of the experimental measured value. The vortex rope results pressure pulsations propagating in the system whose frequency is also perceive in the runner and upstream the runner.

  18. Quantitative Analysis of Tremors in Welders

    Directory of Open Access Journals (Sweden)

    Paul A. Nausieda

    2011-05-01

    Full Text Available Background: Workers chronically exposed to manganese in welding fumes may develop an extra-pyramidal syndrome with postural and action tremors. Objectives: To determine the utility of tremor analysis in distinguishing tremors among workers exposed to welding fumes, patients with Idiopathic Parkinson’s Disease (IPD and Essential Tremor (ET. Methods: Retrospective study of recorded tremor in subjects from academic Movement Disorders Clinics and Welders. Quantitative tremor analysis was performed and associated with clinical status. Results: Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended. Mean center frequencies (Cf of welders and patients with ET were significantly higher than the mean Cf of PD subjects. Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects. Conclusions: In the context of an appropriate exposure history and neurological examination, tremor analysis may be useful in the diagnosis of manganese-related extra-pyramidal manifestations.

  19. Effects of Alprazolam on Cortical Activity and Tremors in Patients with Essential Tremor

    Science.gov (United States)

    Ibáñez, Jaime; González de la Aleja, Jesús; Gallego, Juan A.; Romero, Juan P.; Saíz-Díaz, Rosana A.; Benito-León, Julián; Rocon, Eduardo

    2014-01-01

    Background Essential tremor (ET) is characterised by postural and action tremors with a frequency of 4–12 Hz. Previous studies suggest that the tremor activity originates in the cerebello-thalamocortical pathways. Alprazolam is a short-acting benzodiazepine that attenuates tremors in ET. The mechanisms that mediate the therapeutic action of alprazolam are unknown; however, in healthy subjects, benzodiazepines increase cortical beta activity. In this study, we investigated the effect of alprazolam both on beta and tremor-related cortical activity and on alterations in tremor presentation in ET patients. Therefore, we characterised the dynamics of tremor and cortical activity in ET patients after alprazolam intake. Methods We recorded hand tremors and contralateral cortical activity in four recordings before and after a single dose of alprazolam. We then computed the changes in tremors, cortico-muscular coherence, and cortical activity at the tremor frequency and in the beta band. Results Alprazolam significantly attenuated tremors (EMG: 76.2±22.68%), decreased cortical activity in the tremor frequency range and increased cortical beta activity in all patients (Ptremor frequency became non-significant (Ptremor severity and the increased ratio of cortical activity in the beta band to the activity observed in the tremor frequency range. Conclusions This study provides the first quantitative analysis of tremor reduction following alprazolam intake. We observed that the tremor severity decreased in association with an increased ratio of beta to tremor-related cortical activity. We hypothesise that the increase in cortical beta activity may act as a blocking mechanism and may dampen the pathological oscillatory activity, which in turn attenuates the observed tremor. PMID:24667763

  20. Harmaline Tremor: Underlying Mechanisms in a Potential Animal Model of Essential Tremor

    Directory of Open Access Journals (Sweden)

    Adrian Handforth

    2012-09-01

    Full Text Available Background: Harmaline and harmine are tremorigenic β-carbolines that, on administration to experimental animals, induce an acute postural and kinetic tremor of axial and truncal musculature. This drug-induced action tremor has been proposed as a model of essential tremor. Here we review what is known about harmaline tremor.Methods: Using the terms harmaline and harmine on PubMed, we searched for papers describing the effects of these β-carbolines on mammalian tissue, animals, or humans.Results: Investigations over four decades have shown that harmaline induces rhythmic burst-firing activity in the medial and dorsal accessory inferior olivary nuclei that is transmitted via climbing fibers to Purkinje cells and to the deep cerebellar nuclei, then to brainstem and spinal cord motoneurons. The critical structures required for tremor expression are the inferior olive, climbing fibers, and the deep cerebellar nuclei; Purkinje cells are not required. Enhanced synaptic norepinephrine or blockade of ionic glutamate receptors suppresses tremor, whereas enhanced synaptic serotonin exacerbates tremor. Benzodiazepines and muscimol suppress tremor. Alcohol suppresses harmaline tremor but exacerbates harmaline-associated neural damage. Recent investigations on the mechanism of harmaline tremor have focused on the T-type calcium channel.Discussion: Like essential tremor, harmaline tremor involves the cerebellum, and classic medications for essential tremor have been found to suppress harmaline tremor, leading to utilization of the harmaline model for preclinical testing of antitremor drugs. Limitations are that the model is acute, unlike essential tremor, and only approximately half of the drugs reported to suppress harmaline tremor are subsequently found to suppress tremor in clinical trials.

  1. Olfaction and essential tremor Olfato no tremor essencial

    Directory of Open Access Journals (Sweden)

    Lucas Barasnevicius Quagliato

    2009-03-01

    Full Text Available OBJECTIVE: To characterize the olfactory identification in 40 essential tremor (ET patients, with the University of Pennsylvania 12 Smell Identification Test (UPSIT, to correlate UPSIT scores to clinical and epidemiological data and to compare it to 89 aged matched controls. METHOD: Patients were assessed using ET Clinical Scale of Evaluation and UPSIT. RESULTS: In patients with ET, the UPSIT medium score was 9.10, similar to the control group (9.11, which was also observed in all age groups. ET severity did not correlate to UPSIT scores. CONCLUSION: This study demonstrated normality of olfactory identification on ET, qualifying UPSIT to be an important tool on tremor differential diagnosis of undetermined origin.OBJETIVO: Caracterizar a identificação olfatória em 40 pacientes com tremor essencial, através do Teste de Identificação de 12 Cheiros da Universidade de Pensilvânia (TICUP, correlacioná-la aos dados clínicos e epidemiológicos e compará-la com 89 indivíduos normais. MÉTODO: Os pacientes foram avaliados com a Escala Clínica de Avaliação do TE e com o TICUP. RESULTADOS: A média de acertos no TICUP nos pacientes com TE foi 9,10, semelhante à do grupo controle (9,11, sendo isso observado em todas as faixas etárias. A gravidade do TE não se correlacionou com o resultado do TICUP. CONCLUSÃO: Este estudo demonstrou normalidade da identificação olfatória no TE, qualificando o TICUP como ferramenta importante no diagnóstico diferencial dos tremores de causa indeterminada.

  2. Using Portable Transducers to Measure Tremor Severity

    Directory of Open Access Journals (Sweden)

    Rodger Elble

    2016-05-01

    Full Text Available Background: Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor. Methods: Medline was searched via PubMed.gov in December 2015 using the Boolean expression “tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer.” Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, and 105 papers written in English were reviewed in detail. Results: Accelerometers, gyroscopes, and digitizing tablets are used most commonly, but few are sold for the purpose of measuring tremor. Consequently, most software for tremor analysis is developed by the user. Wearable transducers are capable of recording tremor continuously, in the absence of a clinician. Tremor amplitude, frequency, and occurrence (percentage of time with tremor can be computed. Tremor amplitude and occurrence correlate strongly with clinical ratings of tremor severity. Discussion: Transducers provide measurements of tremor amplitude that are objective, precise, and valid, but the precision and accuracy of transducers are mitigated by natural variability in tremor amplitude. This variability is so great that the minimum detectable change in amplitude, exceeding random variability, is comparable for scales and transducers. Research is needed to determine the feasibility of detecting smaller change using averaged data from continuous long-term recordings with wearable transducers.

  3. Avaliação vestibular no tremor essencial Vestibular evaluation in the essential tremor

    Directory of Open Access Journals (Sweden)

    Bianca Simone Zeigelboim

    2008-01-01

    Full Text Available TEMA: o tremor essencial é familial em cerca de 50% dos casos, com uma herança autossômica, possui início insidioso e é lentamente progressivo. PROCEDIMENTOS: avaliou-se no Setor de Otoneurologia de um Hospital Particular em fevereiro de 2007, uma paciente do sexo feminino, branca, 59 anos, casada, artista plástica, com história de tremor na cabeça desde os dois anos de idade (sic. A paciente relata queixa de tontura há vários meses de origem súbita sem acompanhamento de náusea e/ou queda. Nega perda de força muscular e formigamento em membros superiores e inferiores, rebaixamento da acuidade auditiva e zumbido. A paciente relata que um de seus filhos possuiu tremor nas mãos há dois anos e avós maternos e paternos com Parkinson. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica e avaliação vestibular por meio da vectoeletronistagmografia. RESULTADOS: observaram-se os seguintes achados ao exame vestibular: nistagmo de posicionamento com características centrais, nistagmo espontâneo presente com os olhos abertos, nistagmo semi-espontâneo do tipo múltiplo e hiper-reflexia em valor absoluto à prova calórica 20ºC (OD e OE. CONCLUSÃO: o exame vestibular mostrou-se sensível e importante para captar alterações em provas que sugerissem envolvimento do sistema nervoso central.BACKGROUND: essential tremors are family-related in about 50% of the cases with an autosomal inheritance and they register an insidious beginning with a slow progression. PROCEDURE: a 59 year old, white female patient, married and whose occupation is a plastic artist with a history of head tremors since she was two years (sic old was evaluated in the Otoneurology sector of a private hospital, during the period from February 2007. The patient had been complaining of dizziness from unknown origin for several months without accompanying nausea and/or falls. She denied any loss of muscular strength or tingling in her upper and lower

  4. Fixation of two part fracture of radial head by pre-bend K-wire: An ...

    African Journals Online (AJOL)

    The study was aimed to see the functional status of elbow after fixation with pre bend K- wire in Mason type II Radial head fractures. We have studied eight patients (3 females and 5 males) with Mason type II isolated radial head fractures aged between 15 and 65 years (average 39 years) who underwent open reduction and ...

  5. Beta-adrenergic modulation of tremor and corticomuscular coherence in humans.

    Directory of Open Access Journals (Sweden)

    Mark R Baker

    Full Text Available Coherence between the bioelectric activity of sensorimotor cortex and contralateral muscles can be observed around 20 Hz. By contrast, physiological tremor has a dominant frequency around 10 Hz. Although tremor has multiple sources, it is partly central in origin, reflecting a component of motoneuron discharge at this frequency. The motoneuron response to ~20 Hz descending input could be altered by non-linear interactions with ~10 Hz motoneuron firing. We investigated this further in eight healthy human subjects by testing the effects of the beta-adrenergic agents propranolol (non-selective β-antagonist and salbutamol (β(2-agonist, which are known to alter the size of physiological tremor. Corticomuscular coherence was assessed during an auxotonic precision grip task; tremor was quantified using accelerometry during index finger extension. Experiments with propranolol used a double-blind, placebo-controlled crossover design. A single oral dose of propranolol (40 mg significantly increased beta band (15.3-32.2 Hz corticomuscular coherence compared with placebo, but reduced tremor in the 6.2-11.9 Hz range. Salbutamol (2.5 mg was administered by inhalation. Whilst salbutamol significantly increased tremor amplitude as expected, it did not change corticomuscular coherence. The opposite direction of the effects of propranolol on corticomuscular coherence and tremor, and the fact that salbutamol enhances tremor but does not affect coherence, implies that the magnitude of corticomuscular coherence is little influenced by non-linear interactions with 10 Hz oscillations in motoneurons or the periphery. Instead, we suggest that propranolol and salbutamol may affect both tremor and corticomuscular coherence partly via a central site of action.

  6. Characterizing Orthostatic Tremor Using a Smartphone Application

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    Arjun Balachandar

    2017-07-01

    Full Text Available Background: Orthostatic tremor is one of the few tremor conditions requiring an electromyogram for definitive diagnosis since leg tremor might not be visible to the naked eye.Phenomenology Shown: An iOS application (iSeismometer, ObjectGraph LLC, New York using an Apple iPhone 5 (Cupertino, CA, USA inserted into the patient’s sock detected a tremor with a frequency of 16.4 Hz on both legs.Educational Value: The rapid and straightforward accelerometer-based recordings accomplished in this patient demonstrate the ease with which quantitative analysis of orthostatic tremor can be conducted and, importantly, demonstrates the potential application of this approach in the assessment of any lower limb tremor

  7. Cascadia subduction tremor muted by crustal faults

    Science.gov (United States)

    Wells, Ray; Blakely, Richard J.; Wech, Aaron G.; McCrory, Patricia A.; Michael, Andrew

    2017-01-01

    Deep, episodic slow slip on the Cascadia subduction megathrust of western North America is accompanied by low-frequency tremor in a zone of high fluid pressure between 30 and 40 km depth. Tremor density (tremor epicenters per square kilometer) varies along strike, and lower tremor density statistically correlates with upper plate faults that accommodate northward motion and rotation of forearc blocks. Upper plate earthquakes occur to 35 km depth beneath the faults. We suggest that the faults extend to the overpressured megathrust, where they provide fracture pathways for fluid escape into the upper plate. This locally reduces megathrust fluid pressure and tremor occurrence beneath the faults. Damping of tremor and related slow slip caused by fluid escape could affect fault properties of the megathrust, possibly influencing the behavior of great earthquakes.

  8. Re-emergent tremor in Parkinson's disease.

    Science.gov (United States)

    Belvisi, Daniele; Conte, Antonella; Bologna, Matteo; Bloise, Maria Carmela; Suppa, Antonio; Formica, Alessandra; Costanzo, Matteo; Cardone, Pierluigi; Fabbrini, Giovanni; Berardelli, Alfredo

    2017-03-01

    Re-emergent tremor (RET) is a postural tremor that appears after a variable delay in patients with Parkinson's disease (PD). The aim of the present study was to evaluate the occurrence and the clinical characteristics of RET in a population of patients with PD. We consecutively assessed 210 patients with PD. We collected the patients' demographic and clinical data. RET was clinically characterized in terms of latency, severity and body side affected. We also investigated a possible relationship with motor and non-motor symptoms and differences in the clinical features in patients with and without RET. RET was present in 42/210 patients. The mean latency of RET was 9.20 ± 6.8 seconds. Mean severity was 2.4 ± 1.9. RET was unilateral in 21 patients. Patients with RET had less severe speech, posture and gait disorders and upper limb and global bradykinesia than patients without RET. Similar findings were observed when we compared patients with RET with patients with tremor at rest associated with action tremor, patients with isolated action tremor and patients with no tremor. By contrast, patients with RET tremor did not clinically differ from those with isolated tremor at rest. Our results suggest that patients with RET and patients with isolated tremor at rest represent the same clinical subtype, whereas patients with action tremor (whether isolated or associated with tremor at rest) might belong to a distinct subtype that is clinically worse. Patients with RET represents a benign subtype of PD, even within the tremor-dominant phenotype. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Jaw Tremor Resulting in Broken Teeth: On the Essential Tremor Spectrum

    Directory of Open Access Journals (Sweden)

    Nora C. Hernandez

    2015-11-01

    Full Text Available Background: Jaw tremors in essential tremor (ET rarely represent anything other than a cosmetic concern. Phenomenology Shown: A case of an ET patient whose jaw tremor was severe enough to result in cracked teeth. Educational Value: It behooves treating clinicians to be aware of the full spectrum of this movement disorder.

  10. A review of dental treatment of head and neck cancer patients, before, during and after radiotherapy: part 1.

    Science.gov (United States)

    Jawad, H; Hodson, N A; Nixon, P J

    2015-01-01

    The incidence of head and neck cancer is on the rise. Most head and neck cancers are treated with surgery, radiotherapy, chemotherapy or a combination of these modalities. Patients undergoing radiotherapy can experience several unwanted oral side effects, which have both short and long term implications. Dental general practitioners should be aware of these implications and should liaise closely with the restorative consultants and the oncology team to establish the best oral care pathway. This two-part series is a review of the oral changes that occur during and after radiotherapy and the oral management of head and neck oncology before, during and after radiotherapy. This article deals with both immediate sequelae such as cellulitis, mucositis, dysphagia, dysguesia and weight loss as well as long term sequelae such as rampant caries, trismus, xerostomia and osteoradionecrosis. It also encompasses the importance and need for pre-radiotherapy assessment.

  11. Identifying spatiotemporal migration patterns of non-volcanic tremors using hidden Markov models

    Science.gov (United States)

    Zhuang, J.; Wang, T.; Obara, K.; Tsuruoka, H.

    2015-12-01

    Tremor activity has been recently detected in various tectonic areas worldwide, and is spatially segmented and temporally recurrent. We design a type of hidden Markov models (HMMs) to investigate this phenomenon, where each state represents a distinct segment of tremor sources. We systematically analyze the tremor data from the Tokai region in southwest Japan using this model and find that tremors in this region concentrate around several distinct centers. We find: (1) The system is classified into three classes, background (quiescent), quasi-quiescent, and active states; (2) The region can be separated into two subsystems, the southwest and northeast parts, with most of the active transitions being among the states in each subsystem and the other transitions mainly to the quiescent/quasi-quiescent states; and (3) Tremor activity lasts longer in the northeastern part than in the southwest part. The success of this analysis indicates the power of HMMs in revealing the underlying physical process that drives non-volcanic tremors. Figure: The migration pattern for the HMM with 8 states. Top panel: Observed distances with the center μi of each state overlayed as the red line and ±σi on the left-hand side of the panel in green lines; Middle panel: the tracked most likely state sequence of the 8-state HMM; Bottom panel: the estimated probability of the data being in each state, with blank representing the probability of being in State 1 (the null state).

  12. Resting tremor only: a variant of Parkinson's disease or of essential tremor.

    Science.gov (United States)

    Chang, M H; Chang, T W; Lai, P H; Sy, C G

    1995-06-01

    Resting tremor is one of the characteristic features of Parkinson's disease. However, there are a number of patients who typically have resting tremor alone for at least 5 years without development of other parkinsonian signs or symptoms. The etiology of an isolated resting tremor is still obscure. Recently, positron emission tomography was used to study these patients with isolated resting tremor, and demonstrated a markedly decreased striatal uptake of fluoro-dopa to the range of Parkinson's disease. These findings suggested the existence of a separate subtype, namely, tremulous Parkinson's disease with a manifestation of resting tremor alone. In order to confirm the existence of this subgroup of tremulous Parkinson's disease and further investigate its morphological changes and the usefulness of magnetic resonance imaging, we collected 5 patients who typically have resting tremor for at least 8 years in the absence of other features of Parkinson's disease. MRI was performed and the results of the images showed typical findings of Parkinson's disease with smudging or decreased distance between substantia nigra and red nucleus. Quantitative analysis also demonstrated a significant decrease of the above-noted distance when the resting tremor group was compared to the essential tremor group. Therefore, patients with an isolated resting tremor can have morphological abnormalities in addition to functional disturbances shown by positron emission tomography. To our knowledge, this is the first paper to report that resting tremor is a variant of Parkinson's disease rather than essential tremor, by using a double-blind method, with magnetic resonance imaging to support.

  13. Feasibility study of spectral pattern recognition reveals distinct classes of volcanic tremor

    Science.gov (United States)

    Unglert, K.; Jellinek, A. M.

    2017-04-01

    Systematic investigations of the similarities and differences among volcanic tremor at a range of volcano types may hold crucial information about the plausibility of inferred source mechanisms, which, in turn, may be important for eruption forecasting. However, such studies are rare, in part because of an intrinsic difficulty with identifying tremor signals within very long time series of volcano seismic data. Accordingly, we develop an efficient tremor detection algorithm and identify over 12,000h of volcanic tremor on 24 stations at Kīlauea, Okmok, Pavlof, and Redoubt volcanoes. We estimate spectral content over 5-minute tremor windows, and apply a novel combination of Principal Component Analysis (PCA) and hierarchical clustering to identify patterns in the tremor spectra. Analyzing several stations from a given volcano together reveals different styles of tremor within individual volcanic settings. In addition to identifying tremor properties common to all stations in a given network, we find localized tremor signals including those related to processes such as lahars or dike intrusions that are only observed on some of the stations within a network. Subsequent application of our analysis to a combination of stations from the different volcanoes reveals that at least three main tremor classes can be detected across all settings. Whereas a regime with a ridge of high power distributed over 1-2Hz and a gradual decay of spectral power towards higher frequencies is observed dominantly at three volcanoes (Kīlauea, Okmok, Redoubt) with magma reservoirs centered at less than 5km below sea level (b.s.l.), a spectrum with a steeper slope and a narrower peak at 1-2Hz is observed only in association with open vents (Kīlauea and Pavlof). A third regime with a peak at approximately 3Hz is confined to two stratovolcanoes (Pavlof and Redoubt). These observations suggest generic relationships between the spectral character of the observed signals and volcano

  14. Geophysics. Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interface.

    Science.gov (United States)

    Yamashita, Y; Yakiwara, H; Asano, Y; Shimizu, H; Uchida, K; Hirano, S; Umakoshi, K; Miyamachi, H; Nakamoto, M; Fukui, M; Kamizono, M; Kanehara, H; Yamada, T; Shinohara, M; Obara, K

    2015-05-08

    Detection of shallow slow earthquakes offers insight into the near-trench part of the subduction interface, an important region in the development of great earthquake ruptures and tsunami generation. Ocean-bottom monitoring of offshore seismicity off southern Kyushu, Japan, recorded a complete episode of low-frequency tremor, lasting for 1 month, that was associated with very-low-frequency earthquake (VLFE) activity in the shallow plate interface. The shallow tremor episode exhibited two migration modes reminiscent of deep tremor down-dip of the seismogenic zone in some other subduction zones: a large-scale slower propagation mode and a rapid reversal mode. These similarities in migration properties and the association with VLFEs strongly suggest that both the shallow and deep tremor and VLFE may be triggered by the migration of episodic slow slip events. Copyright © 2015, American Association for the Advancement of Science.

  15. Nontraumatic head and neck emergencies: a clinical approach. Part 1: cervicofacial swelling, dysphagia, and dyspnea.

    Science.gov (United States)

    Brea Álvarez, B; Tuñón Gómez, M; Esteban García, L; García Hidalgo, C Y; Ruiz Peralbo, R M

    2016-01-01

    Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons: first, they affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Various publications focus on nontraumatic emergencies of the head and neck from the viewpoints of anatomic location or of particular diseases. However, these are not the most helpful viewpoints for dealing with patients in the emergency department, who present with particular signs and symptoms. We propose an analysis starting from the four most common clinical presentations of patients who come to the emergency department for nontraumatic head and neck emergencies: cervical swelling, dysphagia, dyspnea, and loss of vision. Starting from these entities, we develop an approach to the radiologic management and diagnosis of these patients. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Triggered tremor sweet spots in Alaska

    Science.gov (United States)

    Gomberg, Joan; Prejean, Stephanie

    2013-01-01

    To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (probability of triggering tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

  17. Evolution of the cephalopod head complex by assembly of multiple molluscan body parts: Evidence from Nautilus embryonic development.

    Science.gov (United States)

    Shigeno, Shuichi; Sasaki, Takenori; Moritaki, Takeya; Kasugai, Takashi; Vecchione, Michael; Agata, Kiyokazu

    2008-01-01

    Cephalopod head parts are among the most complex occurring in all invertebrates. Hypotheses for the evolutionary process require a drastic body-plan transition in relation to the life-style changes from benthos to active nekton. Determining these transitions, however, has been elusive because of scarcity of fossil records of soft tissues and lack of some of the early developmental stages of the basal species. Here we report the first embryological evidence in the nautiloid cephalopod Nautilus pompilius for the morphological development of the head complex by a unique assembly of multiple archetypical molluscan body parts. Using a specialized aquarium system, we successfully obtained a series of developmental stages that enabled us to test previous controversial scenarios. Our results demonstrate that the embryonic organs exhibit body plans that are primarily bilateral and antero-posteriorly elongated at stereotyped positions. The distinct cephalic compartment, foot, brain cords, mantle, and shell resemble the body plans of monoplacophorans and basal gastropods. The numerous digital tentacles of Nautilus develop from simple serial and spatially-patterned bud-like anlagen along the anterior-posterior axis, indicating that origins of digital tentacles or arms of all other cephalopods develop not from the head but from the foot. In middle and late embryos, the primary body plans largely change to those of juveniles or adults, and finally form a "head" complex assembled by anlagen of the foot, cephalic hood, collar, hyponome (funnel), and the foot-derived epidermal covers. We suggest that extensions of the collar-funnel compartment and free epidermal folds derived from multiple topological foot regions may play an important role in forming the head complex, which is thought to be an important feature during the body plan transition. (c) 2007 Wiley-Liss, Inc.

  18. Deep brain stimulation for the treatment of uncommon tremor syndromes.

    Science.gov (United States)

    Ramirez-Zamora, Adolfo; Okun, Michael S

    2016-08-01

    Deep brain stimulation (DBS) has become a standard therapy for the treatment of select cases of medication refractory essential tremor and Parkinson's disease however the effectiveness and long-term outcomes of DBS in other uncommon and complex tremor syndromes has not been well established. Traditionally, the ventralis intermedius nucleus (VIM) of the thalamus has been considered the main target for medically intractable tremors; however alternative brain regions and improvements in stereotactic techniques and hardware may soon change the horizon for treatment of complex tremors. In this article, we conducted a PubMed search using different combinations between the terms 'Uncommon tremors', 'Dystonic tremor', 'Holmes tremor' 'Midbrain tremor', 'Rubral tremor', 'Cerebellar tremor', 'outflow tremor', 'Multiple Sclerosis tremor', 'Post-traumatic tremor', 'Neuropathic tremor', and 'Deep Brain Stimulation/DBS'. Additionally, we examined and summarized the current state of evolving interventions for treatment of complex tremor syndromes. Expert commentary: Recently reported interventions for rare tremors include stimulation of the posterior subthalamic area, globus pallidus internus, ventralis oralis anterior/posterior thalamic subnuclei, and the use of dual lead stimulation in one or more of these targets. Treatment should be individualized and dictated by tremor phenomenology and associated clinical features.

  19. Afterslip, tremor, and the Denali fault earthquake

    Science.gov (United States)

    Gomberg, Joan; Prejean, Stephanie; Ruppert, Natalia

    2012-01-01

    We tested the hypothesis that afterslip should be accompanied by tremor using observations of seismic and aseismic deformation surrounding the 2002 M 7.9 Denali fault, Alaska, earthquake (DFE). Afterslip happens more frequently than spontaneous slow slip and has been observed in a wider range of tectonic environments, and thus the existence or absence of tremor accompanying afterslip may provide new clues about tremor generation. We also searched for precursory tremor, as a proxy for posited accelerating slip leading to rupture. Our search yielded no tremor during the five days prior to the DFE or in several intervals in the three months after. This negative result and an array of other observations all may be explained by rupture penetrating below the presumed locked zone into the frictional transition zone. While not unique, such an explanation corroborates previous models of megathrust and transform earthquake ruptures that extend well into the transition zone.

  20. Holmes’ Tremor with Shoulder Pain Treated by Deep Brain Stimulation of Unilateral Ventral Intermediate Thalamic Nucleus and Globus Pallidus Internus

    Directory of Open Access Journals (Sweden)

    Sabri Aydın

    2017-05-01

    Full Text Available A 21-year-old male was admitted with severe right arm and hand tremors after a thalamic hemorrhage caused by a traffic accident. He was also suffering from agonizing pain in his right shoulder that manifested after the tremor. Neurologic examination revealed a disabling, severe, and irregular kinetic and postural tremor in the right arm during target-directed movements. There was also an irregular ipsilateral rest tremor and dystonic movements in the distal part of the right arm. The amplitude was moderate at rest and extremely high during kinetic and intentional movements. The patient underwent left globus pallidum internus and ventral intermediate thalamic nucleus deep brain stimulation. The patient improved by more than 80% as rated by the Fahn-Tolosa-Marin Tremor Rating Scale and Visual Analog Scale six months after surgery.

  1. Mathematical model of mechanical parts interconnected electric drives of head and lift in rock digger

    OpenAIRE

    Zavyalov, V. М.; Semykina, I. Yu.

    2007-01-01

    The need for development of new approach to modelling lift and head electric drives of quarry digger in the process of digging has been justified. The differences of the mathematical model suggested from the traditional approach are shown. The disadvantages of existing control systems in digger electric drives are revealed, the method of their removing is proposed.

  2. Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique

    Science.gov (United States)

    Ryberg, T.; Haberland, C.H.; Fuis, G.S.; Ellsworth, W.L.; Shelly, D.R.

    2010-01-01

    Non-volcanic tremor (NVT) has been observed at several subduction zones and at the San Andreas Fault (SAF). Tremor locations are commonly derived by cross-correlating envelope-transformed seismic traces in combination with source-scanning techniques. Recently, they have also been located by using relative relocations with master events, that is low-frequency earthquakes that are part of the tremor; locations are derived by conventional traveltime-based methods. Here we present a method to locate the sources of NVT using an imaging approach for multiple array data. The performance of the method is checked with synthetic tests and the relocation of earthquakes. We also applied the method to tremor occurring near Cholame, California. A set of small-aperture arrays (i.e. an array consisting of arrays) installed around Cholame provided the data set for this study. We observed several tremor episodes and located tremor sources in the vicinity of SAF. During individual tremor episodes, we observed a systematic change of source location, indicating rapid migration of the tremor source along SAF. ?? 2010 The Authors Geophysical Journal International ?? 2010 RAS.

  3. Tremor stability index: a new tool for differential diagnosis in tremor syndromes

    Science.gov (United States)

    Shah, Syed Ahmar; Pedrosa, David J.; Cagnan, Hayriye; Mathy, Alexandre; Chen, Chiung Chu; Martín-Rodríguez, Juan Francisco; Mir, Pablo; Timmerman, Lars; Schwingenschuh, Petra; Bhatia, Kailash; Di Lazzaro, Vincenzo; Brown, Peter

    2017-01-01

    Misdiagnosis among tremor syndromes is common, and can impact on both clinical care and research. To date no validated neurophysiological technique is available that has proven to have good classification performance, and the diagnostic gold standard is the clinical evaluation made by a movement disorders expert. We present a robust new neurophysiological measure, the tremor stability index, which can discriminate Parkinson’s disease tremor and essential tremor with high diagnostic accuracy. The tremor stability index is derived from kinematic measurements of tremulous activity. It was assessed in a test cohort comprising 16 rest tremor recordings in tremor-dominant Parkinson’s disease and 20 postural tremor recordings in essential tremor, and validated on a second, independent cohort comprising a further 50 tremulous Parkinson’s disease and essential tremor recordings. Clinical diagnosis was used as gold standard. One hundred seconds of tremor recording were selected for analysis in each patient. The classification accuracy of the new index was assessed by binary logistic regression and by receiver operating characteristic analysis. The diagnostic performance was examined by calculating the sensitivity, specificity, accuracy, likelihood ratio positive, likelihood ratio negative, area under the receiver operating characteristic curve, and by cross-validation. Tremor stability index with a cut-off of 1.05 gave good classification performance for Parkinson’s disease tremor and essential tremor, in both test and validation datasets. Tremor stability index maximum sensitivity, specificity and accuracy were 95%, 95% and 92%, respectively. Receiver operating characteristic analysis showed an area under the curve of 0.916 (95% confidence interval 0.797–1.000) for the test dataset and a value of 0.855 (95% confidence interval 0.754–0.957) for the validation dataset. Classification accuracy proved independent of recording device and posture. The tremor stability

  4. Essential Tremor: A Neurodegenerative Disease?

    Directory of Open Access Journals (Sweden)

    Julian Benito-Leon

    2011-08-01

    Full Text Available Background: Essential tremor (ET is one of the most common neurological disorders among adults, and is the most common of the many tremor disorders. It has classically been viewed as a benign monosymptomatic condition, yet over the past decade, a growing body of evidence indicates that ET is a progressive condition that is clinically heterogeneous, as it may be associated with a spectrum of clinical features, with both motor and non‐motor elements. In this review, I will describe the most significant emerging milestones in research which, when taken together, suggest that ET is a neurodegenerative condition.Methods: A PubMed search conducted in June 2014 crossing the terms “essential tremor” (ET and “neurodegenerative” yielded 122 entries, 20 of which included the term “neurodegenerative” in the article title. This was supplemented by articles in the author's files that pertained to this topic.Results/Discussion: There is an open and active dialogue in the medical community as to whether ET is a neurodegenerative disease, with considerable evidence in favor of this. Specifically, ET is a progressive disorder of aging associated with neuronal loss (reduction in Purkinje cells as well as other post‐mortem changes that occur in traditional neurodegenerative disorders. Along with this, advanced neuroimaging techniques are now demonstrating distinct structural changes, several of which are consistent with neuronal loss, in patients with ET. However, further longitudinal clinical and neuroimaging longitudinal studies to assess progression are required.

  5. Electrophysiologic characteristics of tremor in Parkinson?s disease and essential tremor

    Directory of Open Access Journals (Sweden)

    Ederson Cichaczewski

    2014-04-01

    Full Text Available Tremor in essential tremor (ET and Parkinson’s disease (PD usually present specific electrophysiologic profiles, however amplitude and frequency may have wide variations. Objective: To present the electrophysiologic findings in PD and ET. Method: Patients were assessed at rest, with posture and action. Seventeen patients with ET and 62 with PD were included. PD cases were clustered into three groups: predominant rest tremor; tremor with similar intensity at rest, posture and during kinetic task; and predominant kinetic tremor. Results: Patients with PD presented tremors with average frequency of 5.29±1.18 Hz at rest, 5.79±1.39 Hz with posture and 6.48±1.34 Hz with the kinetic task. Tremor in ET presented with an average frequency of 5.97±1.1 Hz at rest, 6.18±1 Hz with posture and 6.53±1.2 Hz with kinetic task. Seven (41.2% also showed rest tremor. Conclusion: The tremor analysis alone using the methodology described here, is not sufficient to differentiate tremor in ET and PD.

  6. Posturographic analysis of balance control in patients with essential tremor.

    Science.gov (United States)

    Bove, Marco; Marinelli, Lucio; Avanzino, Laura; Marchese, Roberta; Abbruzzese, Giovanni

    2006-02-01

    Essential tremor (ET) is a common movement disorder causing an important functional disability. ET is generally regarded as a monosymptomatic disorder, but additional signs may be present. We analyzed postural sway in 19 patients with classic ET and in 19 sex- and age-matched normal controls (NC) to uncover possible abnormalities of balance control. Static posturography was performed with eyes open (EO) and closed during quiet stance and during performance of mental calculation or motor sequence of thumb opposition to the other fingers. No significant differences of center of foot pressure (COP) parameters were observed between patients and controls during quiet standing. Visual deprivation induced a similar worsening of postural sway in both groups. Concomitant performance of a cognitive or motor task did not affect COP area, whereas COP path was significantly modified by the cognitive task in both groups. In all EO conditions, the COP path was significantly lower in NC than in ET, but such offset was related only to the group of ET patients with head tremor. This study demonstrates that balance control is only minimally affected in ET, although patients with head involvement and longer disease duration tend to present a reduced postural stability. The "dual-task effect" is less important in ET than in Parkinson's disease patients. Copyright (c) 2005 Movement Disorder Society.

  7. Management of radiation therapy-induced mucositis in head and neck cancer patients. Part I: Clinical significance, pathophysiology and prevention

    Directory of Open Access Journals (Sweden)

    Wei Cheong Ngeow

    2011-12-01

    Full Text Available Oropharyngeal mucositis is the acute inflammatory and ulcerative reaction of the oral mucosa following radiation therapy to the head and neck region. It is such a common problem that nearly all head and neck cancer patients develop some degree of mucositis. This complication is usually transient in nature but it also represents an important clinical problem as it is a painful, debilitating, dose-dependent side effect for which there is no widely acceptable prophylaxis or effective treatment. As several authoritative groups have recently either undertaken systematic reviews or issued guidelines on the management of mucositis, it is the aim of this review to provide instead an overview of all the possible remedies available, as well as highlighting to researchers the gaps that need to be filled. The first part of this review outlines the clinical significance and pathophysiology of radiation-induced mucositis, and looks into some of the preventive approaches available.

  8. A review of dental treatment of head and neck cancer patients, before, during and after radiotherapy: part 2.

    Science.gov (United States)

    Jawad, H; Hodson, N A; Nixon, P J

    2015-01-01

    The incidence of head and neck cancer is on the rise. Radiation therapy is one of the major treatment modalities for the management of oral malignancies. As with any treatment modality, radiation therapy is associated with various complications. The second part of this series is a review of the oral changes that occur during and after radiotherapy and the oral management of head and neck oncology patients before, during and after radiotherapy. Dental practitioners will encounter patients who have been affected by cancer or who are current cancer patents. General dental practitioners (GDPs) have a vital and proactive role in supporting such patients. The aim of this article is to review the oral management of these patients during and after radiotherapy, and gives practical advice for GDPs and their teams in the long-term care of these patients.

  9. Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes

    Science.gov (United States)

    Shelly, David R.; Peng, Zhigang; Hill, David P.; Aiken, Chastity

    2011-01-01

    The passage of radiating seismic waves generates transient stresses in the Earth's crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the triggering stress has passed. Here we scrutinize the location and timing of tremor on the San Andreas fault between 2001 and 2010 in relation to distant earthquakes. We observe tremor on the San Andreas fault that is initiated by passing seismic waves, yet migrates along the fault at a much slower velocity than the radiating seismic waves. We suggest that the migrating tremor records triggered slow slip of the San Andreas fault as a propagating creep event. We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  10. Evaluation of precipitates used in strainer head loss testing. Part I. Chemically generated precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, Chi Bum, E-mail: bahn@anl.go [Argonne National Laboratory, Argonne, IL 60439 (United States); Kasza, Ken E.; Shack, William J.; Natesan, Ken [Argonne National Laboratory, Argonne, IL 60439 (United States); Klein, Paul [The United States Nuclear Regulatory Commission, Rockville, MD 20852 (United States)

    2009-12-15

    The purpose of the current program was to evaluate the properties of chemical precipitates proposed by industry that have been used in sump strainer head loss testing. Specific precipitates that were evaluated included aluminum oxyhydroxide (AlOOH) and sodium aluminum silicate (SAS) prepared according to the procedures in WCAP-16530-NP, along with precipitates formed from injecting chemicals into the test loop according to the procedure used by one sump strainer test vendor for U.S. pressurized water reactors. The settling rates of the surrogate precipitates are strongly dependent on their particle size and are reasonably consistent with those expected from Stokes' Law or colloid aggregation models. Head loss tests showed that AlOOH and SAS surrogates are quite effective in increasing the head loss across a perforated pump inlet strainer that has an accumulated fibrous debris bed. The characteristics of aluminum hydroxide precipitate using sodium aluminate were dependent on whether it was formed in high-purity or ordinary tap water and whether excess silicate was present or not.

  11. Evaluation of precipitates used in strainer head loss testing : Part I. chemically generated precipitates.

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, C. B.; Kasza, K. E.; Shack, W. J.; Natesan, K.; Klein, P.; Nuclear Engineering Division

    2009-12-01

    The purpose of the current program was to evaluate the properties of chemical precipitates proposed by industry that have been used in sump strainer head loss testing. Specific precipitates that were evaluated included aluminum oxyhydroxide (AlOOH) and sodium aluminum silicate (SAS) prepared according to the procedures in WCAP-16530-NP, along with precipitates formed from injecting chemicals into the test loop according to the procedure used by one sump strainer test vendor for U.S. pressurized water reactors. The settling rates of the surrogate precipitates are strongly dependent on their particle size and are reasonably consistent with those expected from Stokes Law or colloid aggregation models. Head loss tests showed that AlOOH and SAS surrogates are quite effective in increasing the head loss across a perforated pump inlet strainer that has an accumulated fibrous debris bed. The characteristics of aluminum hydroxide precipitate using sodium aluminate were dependent on whether it was formed in high-purity or ordinary tap water and whether excess silicate was present or not.

  12. Tremor

    Science.gov (United States)

    ... Research Funded by NINDS Basic Neuroscience Clinical Research Translational Research Research at NINDS Focus on Research Alzheimer's & Related Dementias Bioengineering Epilepsy Health Disparities Neural Interfaces Parkinson's Disease Spinal Cord Injury ...

  13. Tremor

    Science.gov (United States)

    ... clothes with Velcro fasteners or using button hooks Cooking or eating with utensils that have a larger ... member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www. ...

  14. Bilateral Hypertrophic Olivary Degeneration and Holmes Tremor without Palatal Tremor: An Unusual Association

    Science.gov (United States)

    Cosentino, Carlos; Velez, Miriam; Nuñez, Yesenia; Palomino, Henry; Quispe, Darko; Flores, Martha; Torres, Luis

    2016-01-01

    Background Lesions in the Guillain–Mollaret triangle or dentate-rubro-olivary pathway may lead to hypertrophic olivary degeneration (HOD), a secondary trans-synaptic degeneration of the inferior olivary nucleus. HOD is usually associated with palatal tremor and rarely with Holmes tremor. Bilateral HOD is a very unusual condition and very few cases are reported. Case Report We report here two cases of bilateral HOD after two different vascular lesions located at the decussation of superior cerebellar peduncles, thus impairing both central tegmental tracts and interrupting bilaterally the dentate-rubral-olivary pathway. Interestingly, both developed bilateral Holmes tremor but not palatal tremor. Discussion Lesions in some of the components in the Guillain–Mollaret triangle may develop Holmes tremor with HOD and without palatal tremor. Magnetic resonance imaging is an invaluable tool in these cases. Better understanding of the pathways in this loop is needed. PMID:27536461

  15. Bilateral Hypertrophic Olivary Degeneration and Holmes Tremor without Palatal Tremor: An Unusual Association

    Directory of Open Access Journals (Sweden)

    Carlos Cosentino

    2016-07-01

    Full Text Available Background: Lesions in the Guillain–Mollaret triangle or dentate-rubro-olivary pathway may lead to hypertrophic olivary degeneration (HOD, a secondary trans-synaptic degeneration of the inferior olivary nucleus. HOD is usually associated with palatal tremor and rarely with Holmes tremor. Bilateral HOD is a very unusual condition and very few cases are reported. Case Report: We report here two cases of bilateral HOD after two different vascular lesions located at the decussation of superior cerebellar peduncles, thus impairing both central tegmental tracts and interrupting bilaterally the dentate-rubral-olivary pathway. Interestingly, both developed bilateral Holmes tremor but not palatal tremor. Discussion: Lesions in some of the components in the Guillain–Mollaret triangle may develop Holmes tremor with HOD and without palatal tremor. Magnetic resonance imaging is an invaluable tool in these cases. Better understanding of the pathways in this loop is needed.

  16. TREMOR12: An Open-Source Mobile App for Tremor Quantification

    Science.gov (United States)

    Kubben, Pieter L.; Kuijf, Mark L.; Ackermans, Linda P.C.M.; Leentjes, Albert F.G.; Temel, Yasin

    2016-01-01

    Background Evaluating the effect of treatment of tremor is mostly performed with clinical rating scales. Mobile applications facilitate a more rapid, objective, and quantitative evaluation of treatment effect. Existing mobile apps do not offer raw data access, which limits algorithm development. Objective To develop a novel open-source mobile app for tremor quantification. Methods TREMOR12 is an open-source mobile app that samples acceleration, rotation, rotation speed, and gravity, each in 3 axes and time-stamped in a frequency up to 100 Hz. The raw measurement data can be exported as a comma-separated value file for further analysis in the TREMOR12P data processing module. The app was evaluated with 3 patients suffering from essential tremor, who were between 55 and 71 years of age. Results This proof-of-concept study shows that the TREMOR12 app is able to detect and register tremor characteristics such as acceleration, rotation, rotation speed, and gravity in a simple and nonburdensome way. The app is compatible with current regulatory oversight by the European Union (MEDDEV regulations) and the Food and Drug Administration (FDA) guidance on mobile medical applications. Conclusion TREMOR12 offers low-cost tremor quantification for research purposes and algorithm development, and may help to improve treatment evaluation. PMID:27395052

  17. TREMOR12: An Open-Source Mobile App for Tremor Quantification.

    Science.gov (United States)

    Kubben, Pieter L; Kuijf, Mark L; Ackermans, Linda P C M; Leentjes, Albert F G; Temel, Yasin

    2016-01-01

    Evaluating the effect of treatment of tremor is mostly performed with clinical rating scales. Mobile applications facilitate a more rapid, objective, and quantitative evaluation of treatment effect. Existing mobile apps do not offer raw data access, which limits algorithm development. To develop a novel open-source mobile app for tremor quantification. TREMOR12 is an open-source mobile app that samples acceleration, rotation, rotation speed, and gravity, each in 3 axes and time-stamped in a frequency up to 100 Hz. The raw measurement data can be exported as a comma-separated value file for further analysis in the TREMOR12P data processing module. The app was evaluated with 3 patients suffering from essential tremor, who were between 55 and 71 years of age. This proof-of-concept study shows that the TREMOR12 app is able to detect and register tremor characteristics such as acceleration, rotation, rotation speed, and gravity in a simple and nonburdensome way. The app is compatible with current regulatory oversight by the European Union (MEDDEV regulations) and the Food and Drug Administration (FDA) guidance on mobile medical applications. TREMOR12 offers low-cost tremor quantification for research purposes and algorithm development, and may help to improve treatment evaluation. © 2016 S. Karger AG, Basel.

  18. Electrophysiologic Assessments of Involuntary Movements: Tremor and Myoclonus

    Directory of Open Access Journals (Sweden)

    Hyun-Dong Park

    2009-05-01

    Full Text Available Tremor is defined as a rhythmical, involuntary oscillatory movement of a body part. Although neurological examination reveals information regarding its frequency, regularity, amplitude, and activation conditions, the electrophysiological investigations help in confirming the tremor, in differentiating it from other hyperkinetic disorders like myoclonus, and may provide etiological clues. Accelerometer with surface electromyogram (EMG can be used to document the dominant frequency of a tremor, which may be useful as certain frequencies are more characteristic of specific etiologies than others hyperkinetic disorders. It may show rhythmic bursts, duration and activation pattern (alternating or synchronous. Myoclonus is a quick, involuntary movement. Electrophysiological studies may helpful in the evaluation of myoclonus, not only for confirming the clinical diagnosis but also for understanding the underlying physiological mechanisms. Electroencephalogram (EEG-EMG correlates can give us important information about myoclonus. Jerk-locked back-averaging and evoked potentials with recording of the long-latency, long-loop reflexes are currently available to study the pathophysiology of myoclonus.

  19. Characteristics of Task-specific Tremor in String Instrument Players

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    André Lee

    2014-06-01

    Full Text Available Background: In recent studies primary bowing tremor has been described; however, tremor frequency has never been quantitatively assessed. In addition to describing phenomenological aspects of tremor we thus aimed at assessing tremor frequency. Our hypothesis was that primary bowing tremor is similar to the phenomenological aspects and frequency of primary writing tremor.Methods: We quantified primary bowing tremor in four violinists under two conditions: open strings and a G major scale. Data were analyzed using empirical mode decomposition because it takes into account non‐stationarity and non‐linearity of signals. For each patient we further described tremor phenomenology and assessed symptom onset, risk factors, medication, and family history with a structured anamnesis. We compare the findings to previous findings for primary bowing tremor and primary writing tremor.Results: We mainly found a flexion–extension tremor of the wrist with a frequency range of 4.7–6.7 Hz. There was no significant difference between the conditions. Mean onset age was 43±2.4 years. Medication included trihexyphenidyl, propranolol, primidone, and botulinum toxin. We found a positive family history in two patients and an injury prior to symptom onset in another two patients. Comparison of onset age, frequency range, family history, and injuries prior to onset revealed that our findings are very similar to previous findings on primary bowing tremor and primary writing tremor.Discussion: Our findings confirmed our hypothesis that primary bowing tremor is similar to primary writing tremor, with regard to phenomenology and epidemiology as well as tremor frequency. There was no difference in tremor frequency between conditions, suggesting that tremor is not influenced by bimanual coordination or bowing speed. Our findings thus provide new phenomenological aspects and may contribute to a better understanding of primary bowing tremor.

  20. Management of tremor in medieval Persia.

    Science.gov (United States)

    Zargaran, Arman; Zarshenas, Mohammad M; Mehdizadeh, Alireza; Mohagheghzadeh, Abdolali

    2013-01-01

    Tremor has been described in traditional systems of medicine throughout history. Persian medicine was one of those systems in medieval times and in it neurology and neurosurgery were also widely practiced and accepted. Based on the main Persian medical manuscripts, the current study focuses on the medieval concept of tremor as an important neurological disorder in order to clarify the development of neurology. Accordingly, three main approaches to the control and treatment of tremor in traditional Persian medicine are considered. First is lifestyle modification. The administration of simple medicines is the second, and the last is the application of compound medicines. Our study shows how much was known about tremor in traditional Persian medicine.

  1. Relations between tectonic tremor and metamorphic processes

    Science.gov (United States)

    Fagereng, A.; Diener, J. F.

    2011-12-01

    Tectonic tremor appears to require low effective stress conditions, and is therefore commonly inferred to correlate with zones of high fluid pressure. In subduction settings, tremor generally occurs near the down-dip end of the interseismically locked zone of the subduction thrust interface. We calculate the stable mineral assemblages in the subducting slab, and find that slab dehydration is not continuous, but rather restricted to a few reactions localized in pressure-temperature space. Along geothermal gradients applicable to Shikoku and Cascadia, our calculations indicate that localized voluminous water release from the breakdown of lawsonite and chlorite+glaucophane respectively, occurs near the tremor source region at the down-dip limit of the locked zone. The shape of the pressure-temperature path for the subducting slab prevents fluid release at depths above and below where these dehydration reactions occur. It therefore appears that tremor in these locations correlate with site-specific metamorphic dehydration reactions. Tremor is also observed along the deep extension of the central San Andreas Fault. We calculate the stable mineral assemblages in basalt and greywacke, representing main components of the Franciscan Complex melange rocks forming the protolith of San Andreas fault rocks. From thermal models and surface heat flow data it is apparent that the tremor source region is cooling and experiencing retrograde metamorphic conditions. Several mineralogical transitions occur at the temperature-depth conditions of tremor on the deep San Andreas, and during retrograde metamorphism these reactions lead to localized, significant removal of free water from the fault zone and an associated volume decrease. Contrary to subduction-related tremor, tremor on the San Andreas fault is therefore not linked to fluid production within the fault zone; rather it might be related to volume change and/or fault zone weakening that occurs as phyllosilicates replace more

  2. Cerebral activation pattern in primary writing tremor

    OpenAIRE

    Berg, D; Preibisch, C; Hofmann, E; Naumann, M

    2000-01-01

    OBJECTIVE—To compare the cerebral activation pattern during writing of patients with writing tremor with healthy controls using functional MRI
METHODS—Three patients with writing tremor and 10 healthy controls were examined using a 1.5 Tesla scanner. All subjects performed a paradigm of alternating 30 second periods of rest or writing. For functional imaging 60 EPI multislice data sets were acquired. All images were analyzed using SPM96 software. Data were analyzed for the grou...

  3. Subthalamic and Cortical Local Field Potentials Associated with Pilocarpine-Induced Oral Tremor in the Rat.

    Science.gov (United States)

    Long, Lauren L; Podurgiel, Samantha J; Haque, Aileen F; Errante, Emily L; Chrobak, James J; Salamone, John D

    2016-01-01

    Tremulous jaw movements (TJMs) are rapid vertical deflections of the lower jaw that resemble chewing but are not directed at any particular stimulus. In rodents, TJMs are induced by neurochemical conditions that parallel those seen in human Parkinsonism, including neurotoxic or pharmacological depletion of striatal dopamine (DA), DA antagonism, and cholinomimetic administration. Moreover, TJMs in rodents can be attenuated by antiparkinsonian agents, including levodopa (L-DOPA), DA agonists, muscarinic antagonists, and adenosine A2A antagonists. In human Parkinsonian patients, exaggerated physiological synchrony is seen in the beta frequency band in various parts of the cortical/basal ganglia/thalamic circuitry, and activity in the tremor frequency range (3-7 Hz) also has been recorded. The present studies were undertaken to determine if tremor-related local field potential (LFP) activity could be recorded from motor cortex (M1) or subthalamic nucleus (STN) during the TJMs induced by the muscarinic agonist pilocarpine, which is a well-known tremorogenic agent. Pilocarpine induced a robust TJM response that was marked by rhythmic electromyographic (EMG) activity in the temporalis muscle. Compared to periods with no tremor activity, TJM epochs were characterized by increased LFP activity in the tremor frequency range in both neocortex and STN. Tremor activity was not associated with increased synchrony in the beta frequency band. These studies identified tremor-related LFP activity in parts of the cortical/basal ganglia circuitry that are involved in the pathophysiology of Parkinsonism. This research may ultimately lead to identification of the oscillatory neural mechanisms involved in the generation of tremulous activity, and promote development of novel treatments for tremor disorders.

  4. Clinical Application of Cone-Beam Computed Tomography of the Rabbit Head: Part 1 - Normal Dentition

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    GG Comet Riggs

    2016-10-01

    Full Text Available Domestic rabbits (Oryctolagus cuniculus are increasingly popular as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental diseases. Diagnostic approaches for dental disease include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT. CT overcomes many limitations of standard radiography by permitting cross-sectional images of the rabbit head in multiple planes without superimposition of anatomic structures. Cone-beam CT (CBCT is an oral and maxillofacial imaging modality that produces high-resolution images. The objective of this study was to describe and compare the normal anatomic features of the dentition and surrounding maxillofacial structures in healthy rabbits on CBCT and conventional CT. Ten New Zealand white rabbit cadaver heads were scanned using CBCT and conventional CT. Images were evaluated using Anatomage Invivo 5 software. The maxillofacial anatomy was labeled on CBCT images and the mean lengths and widths of the teeth were determined. The visibility of relevant dental and anatomic features (pulp cavity, germinal center, tooth outline, periodontal ligament were scored and compared between conventional CT and CBCT. The thinnest teeth were the maxillary second incisor teeth at 1.29 ± 0.26 mm and the maxillary third molar teeth at 1.04 ±0.10 mm. In general, it was found that CBCT was superior to conventional CT when imaging the dentition. Importantly, the periodontal ligament was significantly (P<0.01 more visible on CBCT than on conventional CT. Ability to see the periodontal ligament with such detail may allow earlier detection and treatment of periodontal disease in rabbits. This study is the first of its kind and shows the feasibility and yield of CBCT when evaluating the maxillofacial features and dentition in rabbits.

  5. Psychogenic Tremor: A Video Guide to Its Distinguishing Features

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    Joseph Jankovic

    2014-08-01

    Full Text Available Background: Psychogenic tremor is the most common psychogenic movement disorder. It has characteristic clinical features that can help distinguish it from other tremor disorders. There is no diagnostic gold standard and the diagnosis is based primarily on clinical history and examination. Despite proposed diagnostic criteria, the diagnosis of psychogenic tremor can be challenging. While there are numerous studies evaluating psychogenic tremor in the literature, there are no publications that provide a video/visual guide that demonstrate the clinical characteristics of psychogenic tremor. Educating clinicians about psychogenic tremor will hopefully lead to earlier diagnosis and treatment. Methods: We selected videos from the database at the Parkinson's Disease Center and Movement Disorders Clinic at Baylor College of Medicine that illustrate classic findings supporting the diagnosis of psychogenic tremor.Results: We include 10 clinical vignettes with accompanying videos that highlight characteristic clinical signs of psychogenic tremor including distractibility, variability, entrainability, suggestibility, and coherence.Discussion: Psychogenic tremor should be considered in the differential diagnosis of patients presenting with tremor, particularly if it is of abrupt onset, intermittent, variable and not congruous with organic tremor. The diagnosis of psychogenic tremor, however, should not be simply based on exclusion of organic tremor, such as essential, parkinsonian, or cerebellar tremor, but on positive criteria demonstrating characteristic features. Early recognition and management are critical for good long-term outcome.

  6. Linking Essential Tremor to the Cerebellum-Animal Model Evidence.

    Science.gov (United States)

    Handforth, Adrian

    2016-06-01

    In this review, we hope to stimulate interest in animal models as opportunities to understand tremor mechanisms within the cerebellar system. We begin by considering the harmaline model of essential tremor (ET), which has ET-like anatomy and pharmacology. Harmaline induces the inferior olive (IO) to burst fire rhythmically, recruiting rhythmic activity in Purkinje cells (PCs) and deep cerebellar nuclei (DCN). This model has fostered the IO hypothesis of ET, which postulates that factors that promote excess IO, and hence PC complex spike synchrony, also promote tremor. In contrast, the PC hypothesis postulates that partial PC cell loss underlies tremor of ET. We describe models in which chronic partial PC loss is associated with tremor, such as the Weaver mouse, and others with PC loss that do not show tremor, such as the Purkinje cell degeneration mouse. We postulate that partial PC loss with tremor is associated with terminal axonal sprouting. We then discuss tremor that occurs with large lesions of the cerebellum in primates. This tremor has variable frequency and is an ataxic tremor not related to ET. Another tremor type that is not likely related to ET is tremor in mice with mutations that cause prolonged synaptic GABA action. This tremor is probably due to mistiming within cerebellar circuitry. In the final section, we catalog tremor models involving neurotransmitter and ion channel perturbations. Some appear to be related to the IO hypothesis of ET, while in others tremor may be ataxic or due to mistiming. In summary, we offer a tentative framework for classifying animal action tremor, such that various models may be considered potentially relevant to ET, subscribing to IO or PC hypotheses, or not likely relevant, as with mistiming or ataxic tremor. Considerable further research is needed to elucidate the mechanisms of tremor in animal models.

  7. Distinguishing the Central Drive to Tremor in Parkinson's Disease and Essential Tremor

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    Brittain, John-Stuart; Cagnan, Hayriye; Mehta, Arpan R.; Saifee, Tabish A.; Edwards, Mark J.

    2015-01-01

    Parkinson's disease (PD) and essential tremor (ET) are the two most common movement disorders. Both have been associated with similar patterns of network activation leading to the suggestion that they may result from similar network dysfunction, specifically involving the cerebellum. Here, we demonstrate that parkinsonian tremors and ETs result from distinct patterns of interactions between neural oscillators. These patterns are reflected in the tremors' derived frequency tolerance, a novel measure readily attainable from bedside accelerometry. Frequency tolerance characterizes the temporal evolution of tremor by quantifying the range of frequencies over which the tremor may be considered stable. We found that patients with PD (N = 24) and ET (N = 21) were separable based on their frequency tolerance, with PD associated with a broad range of stable frequencies whereas ET displayed characteristics consistent with a more finely tuned oscillatory drive. Furthermore, tremor was selectively entrained by transcranial alternating current stimulation applied over cerebellum. Narrow frequency tolerances predicted stronger entrainment of tremor by stimulation, providing good evidence that the cerebellum plays an important role in pacing those tremors. The different patterns of frequency tolerance could be captured with a simple model based on a broadly coupled set of neural oscillators for PD, but a more finely tuned set of oscillators in ET. Together, these results reveal a potential organizational principle of the human motor system, whose disruption in PD and ET dictates how patients respond to empirical, and potentially therapeutic, interventions that interact with their underlying pathophysiology. PMID:25589772

  8. Tectonic tremor and LFEs on a reverse fault in Taiwan: TREMOR AND LFES IN TAIWAN

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Ana C. [Lawrence Livermore National Laboratory, Livermore California USA; Geophysics Department, Stanford University, Stanford California USA; Chao, Kevin [Center for Optimization and Statistical Learning, Northwestern Institute on Complex Systems, Northwestern University, Evanston Illinois USA; Beroza, Gregory C. [Geophysics Department, Stanford University, Stanford California USA

    2017-07-06

    We compare low-frequency earthquakes (LFEs) from triggered and ambient tremor under the southern Central Range, Taiwan. We apply the PageRank algorithm used by Aguiar and Beroza (2014) that exploits the repetitive nature of the LFEs to find repeating LFEs in both ambient and triggered tremor. We use these repeaters to create LFE templates and find that the templates created from both tremor types are very similar. To test their similarity, we use both interchangeably and find that most of both the ambient and triggered tremor match the LFE templates created from either data set, suggesting that LFEs for both events have a common origin. We locate the LFEs by using local earthquake P wave and S wave information and find that LFEs from triggered and ambient tremor locate to between 20 and 35 km on what we interpret as the deep extension of the Chaochou-Lishan Fault.

  9. Comparative study of tectonic tremor locations: Characterization of slow earthquakes in Guerrero, Mexico

    Science.gov (United States)

    Maury, J.; Ide, S.; Cruz-Atienza, V. M.; Kostoglodov, V.; González-Molina, G.; Pérez-Campos, X.

    2016-07-01

    Deep tectonic tremor in Guerrero, Mexico, has been observed using dense temporal seismic networks (i.e., the Meso-American Subduction Experiment and Guerrero Gap Experiment (G-GAP) arrays) during two different time periods. We apply a set of seismic waveform analysis methods to these data sets to constrain the locations of tremors and determine the associated moment tensors. First we detect and locate the tremors. Next, very low frequency (VLF) signals are identified by stacking waveform data during tremor bursts, and their moment tensors are determined. Finally, to better investigate the link between tremors and VLF earthquakes, we detect VLF events using a matched filtering algorithm to search continuous seismic records. None of the 11 VLF events detected by this method occurred in the absence of tremor bursts suggesting they are indeed part of the same phenomena. Unlike previous investigations, our results for the G-GAP period reveal that downdip tremor activity (i.e., in the so-called "sweet spot") is segmented into two patches separated by 40 km in the along-trench direction, indicating possible variations in the geometry of the plate interface and/or slab effective pressure. Moment tensors of VLF signals are consistent with shear slip on the near-horizontal plate interface, but source depths are about 5 km deeper than the established plate interface. The slip directions of the VLF events are slightly ( 10°) counterclockwise of the plate convergence direction, indicating that strain energy promoting left-lateral strike-slip motion may accumulate in the continental crust during the interseismic period.

  10. Insights into the causal relationship between slow slip and tectonic tremor in Guerrero, Mexico

    Science.gov (United States)

    Villafuerte, Carlos; Cruz-Atienza, Víctor M.

    2017-08-01

    Similar to other subduction zones, tectonic tremors (TTs) and slow-slip events (SSEs) take place in the deep segment of the plate interface in Guerrero, Mexico. However, their spatial correlation in this region is not as clear as the episodic tremor and slip observed in Cascadia and Japan. In this study we provide insights into the causal relationship between TTs and SSEs in Guerrero by analyzing the evolution of the deformation fields induced by the long-term 2006 SSE together with new locations of TTs and low-frequency earthquakes (LFEs). Unlike previous studies we find that the SSE slip rate modulates the TT and LFE activity in the whole tremor region. This means that the causal relationship between the SSE and the TT activity directly depends on the stressing rate history of the tremor asperities that is modulated by the surrounding slip rate. We estimated that the frictional strength of the asperities producing tremor downdip in the sweet spot is around 3.2 kPa, which is 2.3 times smaller than the corresponding value updip in the transient zone, partly explaining the overwhelming tremor activity of the sweet spot despite that the slow slip there is smaller. Based on the LFE occurrence-rate history during the interlong-term SSE period, we determined that the short-term SSEs in Guerrero take place further downdip (about 35 km) than previously estimated, with maximum slip of about 8 mm in the sweet spot. This new model features a continuum of slow slip extending across the entire tremor region of Guerrero.

  11. A review of primary writing tremor.

    Science.gov (United States)

    Rana, Abdul Qayyum; Vaid, Haris M

    2012-03-01

    A task-specific tremor (TST) is a rare form of movement disorder that appears while performing or attempting to perform a particular task. Primary writing tremor (PWT) is the most common form of TST which only occurs during the act of writing and hinders it. (Bain PG, Findley LJ, Britton TC, Rothwell JC, Gresty MA, Thompson PD, Marsden CD. MRC Human Movement, and Balance Unit, Institute of Neurology, London, UK. Primary writing tremor. Brain. 1995;118(6):1461-72.) Primary writing tremor type B is present not only during the act of writing but also when the hand assumes a writing posture. (Bain PG, Findley LJ, Britton TC, Rothwell JC, Gresty MA, Thompson PD, Marsden CD. MRC Human Movement and Balance Unit, Institute of Neurology, London, UK. Primary writing tremor. Brain. 1995;118(6):1461-72.) We first of all describe a remarkable case study of a 50-year old, right-handed male who started experiencing a primary writing tremor in his right hand about a year ago. This case was found to be of particular interest because the patient had it relatively difficult when attempting to write numbers as opposed to writing letters. This review further discusses the clinical manifestations of PWT. In addition, three main hypotheses have been proposed for the causation of PWT, although the exact pathophysiology of PWT still remains unknown. It has been suggested that PWT is a separate entity, a variant of essential tremor and not a separate entity, or a type of dystonia. The various treatment options for PWT are discussed including botulinum toxin and oral pharmacotherapy.

  12. Effects of eye-glasses, hair, headgear, and clothing on measured head-related transfer functions Part Ib

    Science.gov (United States)

    Riederer, Klaus A. J.

    2003-10-01

    Extensive head-related transfer function (HRTF) measurements show high HRTF repeatability, consequences of different measurement methods, and conditions covering the whole three-dimensional space [Riederer, J. Audio Eng. Soc. (Abstracts) 46, 1036 (1998), preprint 4846]. This study concentrates on specific effects on HRTFs carefully re-measured on the same Cortex dummy head applying Sennheiser KE4-211-2 microphones at its silicone putty blocked ear-canal entrances, employing 252 sound incidents including seven elevations. The effects of five different wigs (synthetic, natural, thick, thin, long and short hair) with varied hairstyles, four hats (cap, bicycle helmet, mens and womens trilby), clothes (alpaca pullover, bicycling drymax-jacket) and spectacles were investigated under 28 combinations. The influences are highly dependent on direction, frequency, and case. Clothes and eye-glasses affect minimally HRTF; hair has a stronger effect, depending on the actual hairdo (typically above 7 kHz). Hats alter intensively HRTFs (typically above 5 kHz), depending on the model. The measurements give deeper insight to the development of idiosyncratic features in binaural localization cues. The second part of the study addresses their perceptual effects [Riederer, J. Acoust. Soc. Am., this issue]. [Work supported by Graduate School of Electronics, Telecommunication and Automation; thanks to Finnish Broadcasting Company, Mr. Hellstrom; Mrs. Chen.

  13. Ground-motion prediction from tremor

    Science.gov (United States)

    Baltay, Annemarie S.; Beroza, Gregory C.

    2013-01-01

    The widespread occurrence of tremor, coupled with its frequency content and location, provides an exceptional opportunity to test and improve strong ground-motion attenuation relations for subduction zones. We characterize the amplitude of thousands of individual 5 min tremor events in Cascadia during three episodic tremor and slip events to constrain the distance decay of peak ground acceleration (PGA) and peak ground velocity (PGV). We determine the anelastic attenuation parameter for ground-motion prediction equations (GMPEs) to a distance of 150 km, which is sufficient to place important constraints on ground-motion decay. Tremor PGA and PGV show a distance decay that is similar to subduction-zone-specific GMPEs developed from both data and simulations; however, the massive amount of data present in the tremor observations should allow us to refine distance-amplitude attenuation relationships for use in hazard maps, and to search for regional variations and intrasubduction zone differences in ground-motion attenuation.

  14. Botulinum Toxin in Management of Limb Tremor

    Directory of Open Access Journals (Sweden)

    Elina Zakin

    2017-11-01

    Full Text Available Essential tremor is characterized by persistent, usually bilateral and symmetric, postural or kinetic activation of agonist and antagonist muscles involving either the distal or proximal upper extremity. Quality of life is often affected and one’s ability to perform daily tasks becomes impaired. Oral therapies, including propranolol and primidone, can be effective in the management of essential tremor, although adverse effects can limit their use and about 50% of individuals lack response to oral pharmacotherapy. Locally administered botulinum toxin injection has become increasingly useful in the management of essential tremor. Targeting of select muscles with botulinum toxin is an area of active research, and muscle selection has important implications for toxin dosing and functional outcomes. The use of anatomical landmarks with palpation, EMG guidance, electrical stimulation, and ultrasound has been studied as a technique for muscle localization in toxin injection. Earlier studies implemented a standard protocol for the injection of (predominantly wrist flexors and extensors using palpation and EMG guidance. Targeting of muscles by selection of specific activators of tremor (tailored to each patient using kinematic analysis might allow for improvement in efficacy, including functional outcomes. It is this individualized muscle selection and toxin dosing (requiring injection within various sites of a single muscle that has allowed for success in the management of tremors.

  15. The central oscillatory network of orthostatic tremor.

    Science.gov (United States)

    Muthuraman, Muthuraman; Hellriegel, Helge; Paschen, Steffen; Hofschulte, Frank; Reese, Rene; Volkmann, Jens; Witt, K; Deuschl, G; Raethjen, Jan

    2013-09-01

    Orthostatic tremor (OT) is a movement disorder of the legs and trunk that is present in the standing position but typically absent when sitting. The pathological central network involved in orthostatic tremor is still unknown. In this study we analyzed 15 patients with simultaneous high-resolution electroencephalography and electromyography recording to assess corticomuscular coherence. In 1 patient we were able to simultaneously record the local field potential in the ventrolateral thalamus and electroencephalography. Dynamic imaging of coherent source analysis was used to find the sources in the brain that are coherent with the peripheral tremor signal. When standing, the network for the tremor frequency consisted of unilateral activation in the primary motor leg area, supplementary motor area, primary sensory cortex, two prefrontal/premotor sources, thalamus, and cerebellum for the whole 30-second segment recorded. The source coherence dynamics for the primary leg area and the thalamic source signals with the tibialis anterior muscle showed that they were highly coherent for the whole 30 seconds for the contralateral side but markedly decreased after 15 seconds for the ipsilateral side. The source signal and the recorded thalamus signal followed the same time frequency dynamics of coherence in 1 patient. The corticomuscular interaction in OT follows a consistent pattern with an initially bilateral pattern and then a segregated unilateral pattern after 15 seconds. This may add to the feeling of unsteadiness. It also makes the thalamus unlikely as the main source of orthostatic tremor. © 2013 International Parkinson and Movement Disorder Society.

  16. Resting tremor in Parkinson disease: a negative predictor of levodopa-induced dyskinesia.

    Science.gov (United States)

    Kipfer, Stefan; Stephan, Marianne A; Schüpbach, W M Michael; Ballinari, Pietro; Kaelin-Lang, Alain

    2011-08-01

    It is unclear whether patients with different clinical subtypes of Parkinson disease (PD) differ in their risk of developing levodopa-induced dyskinesia (LID) and whether resting tremor is negatively correlated with this risk. To determine whether resting tremor as an initial manifestation of PD negatively correlated with subsequent occurrence and severity of LID and to study the correlations between LID and other epidemiological factors (eg, age at onset of PD and duration of PD). Logistic regression analysis was used to determine predictive factors of LID. Spearman rank correlations between LID and epidemiological factors and motor signs (including tremor) were calculated. Institutional tertiary referral center for movement disorders. Cohort of 85 patients with PD. Occurrence of LID according to the Unified Parkinson Disease Rating Scale part IV. Resting tremor as an initial manifestation of PD was associated with reduced risk of developing LID independent of other predictors of LID (duration of PD, axial signs, and levodopa dose). Resting tremor as an initial manifestation of PD predicts lower probability of developing LID under levodopa treatment.

  17. Essential Tremor (ET): Coping Tips for Everyday Living

    Science.gov (United States)

    ... Options Donate Prev Next IETF > Coping with Essential Tremor > Coping Tips for Everyday Living Coping Tips for ... that can lead to stress with temporarily worsening tremor. In order to assist people who have ET ...

  18. A review on techniques for tremor recording and quantification.

    Science.gov (United States)

    Mansur, Paulo Henrique G; Cury, Lacordaire Kemel P; Andrade, Adriano O; Pereira, Adriano A; Miotto, Guilherme Alessandri A; Soares, Alcimar B; Naves, Eduardo L M

    2007-01-01

    Tremor is the most common movement disorder and differs from other disorders by its repetitive, stereotyped movements, with regular frequency and amplitude. The three most frequent pathological forms of it are the essential tremor (ET), the Parkinson's disease (PD) tremor, and the enhanced physiological tremor. The ET and PD tremor affect the older population mostly. Although there are cases of tremor reported since ancient times, there is currently no consensus about its causes or about its main differential characteristics. In this article, we present a review of the methods more frequently used in measurement and analysis of tremor and the difficulties encountered in the research for the identification of methodologies that allow a significant advance in the study of tremor.

  19. Parkinson's disease tremor is diminished with relaxation guided imagery.

    Science.gov (United States)

    Schlesinger, Ilana; Benyakov, Orna; Erikh, Ilana; Suraiya, Suheir; Schiller, Yitzhak

    2009-10-30

    Patients with Parkinson's disease (PD) may have pronounced tremor that exacerbates during stress. To determine whether PD tremor improves with relaxation guided imagery (RGI) and relaxing music. Twenty patients with PD with moderate to severe tremor participated in sessions where relaxation techniques were implemented. Tremor was objectively monitored using an accelerometer. RGI dramatically decreased tremor in all 20 patients (baseline 270.38 +/- 85.82 vs. RGI 35.57 +/- 43.90 movements per minute P music significantly reduced tremor but to a lesser degree than RGI (220.04 +/- 106.53 movements per minute P = 0.01). Self-relaxation had no significant effect on tremor. RGI can supplement conventional medical treatments for tremor in patients with PD on best medical treatment. (c) 2009 Movement Disorder Society.

  20. Essential Tremor vs. Parkinson's Disease: How Do They Differ?

    Science.gov (United States)

    Essential Tremor (ET) ET vs Parkinson’s disease How do they differ? The characteristics listed in the table below can help differentiate between parkinsonian and essential tremor, but a medical professional should be consulted for ...

  1. Pallidal dysfunction drives a cerebellothalamic circuit into Parkinson tremor

    NARCIS (Netherlands)

    Helmich, R.C.G.; Janssen, M.J.; Oyen, W.J.G.; Bloem, B.R.; Toni, I.

    2011-01-01

    OBJECTIVE: Parkinson disease (PD) is characterized by striatal dopamine depletion, which explains clinical symptoms such as bradykinesia and rigidity, but not resting tremor. Instead, resting tremor is associated with increased activity in a distinct cerebellothalamic circuit. To date, it remains

  2. Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus.

    Science.gov (United States)

    Dirkx, Michiel F; den Ouden, Hanneke E M; Aarts, Esther; Timmer, Monique H M; Bloem, Bastiaan R; Toni, Ivan; Helmich, Rick C

    2017-03-01

    Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic medication reduces tremor in some patients, but many patients have a dopamine-resistant tremor. Using pharmacological functional magnetic resonance imaging, we test how a dopaminergic intervention influences the cerebral circuit involved in Parkinson's tremor. From a sample of 40 patients with Parkinson's disease, we selected 15 patients with a clearly tremor-dominant phenotype. We compared tremor-related activity and effective connectivity (using combined electromyography-functional magnetic resonance imaging) on two occasions: ON and OFF dopaminergic medication. Building on a recently developed cerebral model of Parkinson's tremor, we tested the effect of dopamine on cerebral activity associated with the onset of tremor episodes (in the basal ganglia) and with tremor amplitude (in the cerebello-thalamo-cortical circuit). Dopaminergic medication reduced clinical resting tremor scores (mean 28%, range -12 to 68%). Furthermore, dopaminergic medication reduced tremor onset-related activity in the globus pallidus and tremor amplitude-related activity in the thalamic ventral intermediate nucleus. Network analyses using dynamic causal modelling showed that dopamine directly increased self-inhibition of the ventral intermediate nucleus, rather than indirectly influencing the cerebello-thalamo-cortical circuit through the basal ganglia. Crucially, the magnitude of thalamic self-inhibition predicted the clinical dopamine response of tremor. Dopamine reduces resting tremor by potentiating inhibitory mechanisms in a cerebellar nucleus of the thalamus (ventral intermediate nucleus). This suggests that altered dopaminergic projections to the cerebello-thalamo-cortical circuit have a role

  3. Tremor da escrita: relato de caso

    Directory of Open Access Journals (Sweden)

    Denise Hack Nicaretta

    1994-03-01

    Full Text Available O tremor da escrita é distúrbio precipitado por atividade motora específica, geralmente a escrita. Analisamos este caso sob o ponto de vista clínico e terapêutico. O paciente apresentava tremor ao escrever tomando sua letra ilegível; sem qualquer outra alteração neurológica. Não havia antecedentes familiares, metabólicos, endócrinos, iatrogênicos, tóxicos ou traumáticos. No manuseio terapêutico não ocorreu resposta satisfatória ao propranolol, sendo discreta à primidona. A introdução de anticolinérgicos (tri-hexifenidil evidenciou certa melhora na sintomatologia, com redução do tremor no momento da escrita.

  4. San Andreas tremor cascades define deep fault zone complexity

    Science.gov (United States)

    Shelly, David R.

    2015-01-01

    Weak seismic vibrations - tectonic tremor - can be used to delineate some plate boundary faults. Tremor on the deep San Andreas Fault, located at the boundary between the Pacific and North American plates, is thought to be a passive indicator of slow fault slip. San Andreas Fault tremor migrates at up to 30 m s-1, but the processes regulating tremor migration are unclear. Here I use a 12-year catalogue of more than 850,000 low-frequency earthquakes to systematically analyse the high-speed migration of tremor along the San Andreas Fault. I find that tremor migrates most effectively through regions of greatest tremor production and does not propagate through regions with gaps in tremor production. I interpret the rapid tremor migration as a self-regulating cascade of seismic ruptures along the fault, which implies that tremor may be an active, rather than passive participant in the slip propagation. I also identify an isolated group of tremor sources that are offset eastwards beneath the San Andreas Fault, possibly indicative of the interface between the Monterey Microplate, a hypothesized remnant of the subducted Farallon Plate, and the North American Plate. These observations illustrate a possible link between the central San Andreas Fault and tremor-producing subduction zones.

  5. Diagnóstico diferencial dos tremores

    OpenAIRE

    MATTOS JAMES PITÁGORAS DE

    1998-01-01

    Baseado na revisão da literatura, o autor refere-se aos tremores normal (fisiológico) e anormal (patológico). Analisa particularmente os patológicos, dividindo-os em de repouso e de ação. Com os elementos semiológicos estabelece o diagnóstico diferencial entre os tremores parkinsoniano, essencial severo, rubral, tardio, postural, cinético e os de posição e de ação específica, entre outros.

  6. Unilateral rubral tremors in Wilson′s disease treated with dimercaprol

    Directory of Open Access Journals (Sweden)

    Rahul T Chakor

    2015-01-01

    Full Text Available Tremors are reported as the most frequent neurological manifestation of Wilson′s disease (WD in some series. Postural tremors, rest tremors, action tremors and wing-beating (rubral tremors are the different types of tremors seen in WD. We report a patient of WD with unilateral rubral tremors refractory to 1-year therapy with Penicillamine and anti-tremor medications. The tremors decreased considerably after adding chelation therapy with dimercaprol. Combination of Penicillamine and dimercaprol is an effective decoppering measure in rubral tremors of WD.

  7. Migration of teleseismically triggered tremor in southwestern Japan subduction zone

    Science.gov (United States)

    Kurihara, R.; Obara, K.; Maeda, T.; Takeo, A.

    2016-12-01

    Deep low frequency tremor in subduction zone is sometimes triggered by surface waves from teleseismic earthquakes. In southwestern Japan, a sequence of triggered tremor was reported for the 2004 Sumatra-Andaman earthquake (Miyazawa and Mori, 2006). Such triggered tremor was observed in the ambient tremor zone where the short-term slow slip events episodically occur. However, the triggered tremor is not distributed in the entire source area of ambient tremor, but is concentrated in several fixed spots. In this study, we tried to reveal accurate location of triggered tremor and investigate the spatiotemporal characteristics for understandings of condition and occurrence mechanism of triggered tremor. We detected low frequency earthquakes in tremor sequence triggered by teleseismic wave by using matched filter technique. The data were obtained at 10 NIED Hi-net stations. We used low frequency earthquakes occurred in 2014 detected by JMA as template events. Time duration of the templates is five seconds. We analyzed continuous waveform data for one hour from the origin times of 2004 Sumatra, 2008 Wenchuan, 2012 Sumatra and 2015 Nepal earthquakes. In western Shikoku, detected triggered tremor is concentrated at distant fixed two spots with an average separation of 20 km for analyzed four teleseismic events. Particularly, southwestern spot has a streak-like distribution along the dip direction of the subducting plate. In this spot, we detected along-dip migration of triggered tremor. The migration speed is about 300 km/h for 2008 Wenchuan earthquake and about 20 km/h for 2015 Nepal earthquake. Shelly et al. (2007) reported similar along-dip migration of ambient tremor at velocity from 25 to 150 km/h. Therefore, migrations of triggered tremor detected in this study suggest that the triggered tremor is also associated by slow slip event like as ambient tremor.

  8. Cognition in non-demented Parkinson's disease vs essential tremor: A population-based study.

    Science.gov (United States)

    Sánchez-Ferro, Á; Benito-León, J; Louis, E D; Contador, I; Hernández-Gallego, J; Puertas-Martín, V; Bermejo-Pareja, F

    2017-11-01

    Patients with Parkinson's disease (PD) and essential tremor (ET) have a higher risk of cognitive impairment than age-matched controls. Only a few small studies (11-18 subjects per group) have directly compared the cognitive profile of these conditions. Our aim was to compare the cognitive profile of patients with these two conditions to each other and to healthy individuals in a population-based study of non-demented participants. This investigation was part of the NEDICES study, a survey of the elderly in which 2438 dementia-free participants underwent a short neuropsychological battery. We used nonparametric techniques to evaluate whether there are differences and/or a gradient of impairment across the groups (PD, ET, and controls). Also, we performed a head-to-head comparison of ET and PD, adjusting for age and education. Patients with PD (N=46) and ET (N=180) had poorer cognition than controls (N=2212). An impaired gradient of performance was evident. PD scored lower than ET, and then each of these lower than controls, in memory (P<.05) and verbal fluency (P<.001) tasks. When we compared PD and ET, the former had lower scores in verbal fluency (P<.05), whereas the later had a poorer cognitive processing speed (P<.05). This large population-based study demonstrates that both conditions influence cognitive performance, that a continuum exists from normal controls to ET to PD (most severe), and that although deficits are in many of the same cognitive domains, the affected cognitive domains do not overlap completely. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Dramatic response to levetiracetam in post-ischaemic Holmes’ tremor

    Science.gov (United States)

    Striano, P; Elefante, Andrea; Coppola, Antonietta; Tortora, Fabio; Zara, Federico; Minetti, Carlo

    2009-01-01

    Holmes’ tremor refers to an unusual combination of rest, postural and kinetic tremor of extremities. Common causes of Holmes’ tremor include stroke, trauma, vascular malformations and multiple sclerosis, with lesions involving the thalamus, brain stem or cerebellum. Although some drugs (eg, levodopa and dopaminergic drugs, clonazepam and propranolol) have been occasionally reported to give some benefit, medical treatment of Holmes’ tremor is unsatisfactory, and many patients require thalamic surgery to achieve satisfactory control. We report a patient in whom post-ischaemic Holmes’ tremor dramatically responded to levetiracetam treatment. PMID:21686707

  10. Episodic tremors representing cortical myoclonus are characteristic in Angelman syndrome due to UBE3A mutations.

    Science.gov (United States)

    Goto, Masahide; Saito, Yoshiaki; Honda, Ryoko; Saito, Takashi; Sugai, Kenji; Matsuda, Yuko; Miyatake, Chiharu; Takeshita, Eri; Ishiyama, Akihiko; Komaki, Hirofumi; Nakagawa, Eiji; Sasaki, Masayuki; Uto, Chieko; Kikuchi, Kenjiro; Motoki, Takahiro; Saitoh, Shinji

    2015-02-01

    Neurological manifestations including psychomotor developmental delay and epilepsy in patients with Angelman syndrome caused by ubiquitin protein ligase E3A (UBE3A) mutations has been considered similar but is relatively milder than that in patients with deletion-type Angelman syndrome. This makes the diagnosis of the former subgroup often difficult. We here characterized epilepsy, specifically the types of tremulous movement, in 4 patients (age, 3-38years) with Angelman syndrome caused by UBE3A mutations. Ictal electroencephalography was used to record episodic tremors in all study patients. Jerk-locked averaging was performed using digital electroencephalography and surface electromyogram data from patients who were monitored for 24h. All patients had tremors in the limbs, head, and trunk, which resulted in 2 patients falling backward. These tremors lasted several seconds, and could emerge in clusters for hours in older patients. In addition, the tremors coincided with 7-8Hz rhythmic activity with a frontocentral predominance, diffuse spike-wave bursts, or no apparent change on electroencephalography. In 2 patients, these tremors were confirmed as cortical myoclonus using jerk-locked averaging. The other seizure types were isolated generalized myoclonus and tonic seizures. None of the patients experienced atypical absence seizures. Levetiracetam therapy was effective in controlling the myoclonic events in 2 of the 3 patients. Semirhythmic myoclonus is common in patients with Angelman syndrome caused by UBE3A mutations, and such myoclonic events are often life disabling. The preserved expression of gamma-aminobutyric acid type A receptor subunit genes located proximal to UBE3A might explain the low prevalence of absence seizures in this population. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  11. Prevalence and Correlates of Rest Tremor in Essential Tremor: Cross-Sectional Survey of 831 Patients Across Four Distinct Cohorts

    Science.gov (United States)

    Louis, Elan D.; Hernandez, Nora; Michalec, Monika

    2015-01-01

    Background Essential tremor (ET) is among the most commonly encountered neurological disorders. Its hallmark feature is kinetic tremor. However, other tremors may also occur in ET patients, creating considerable diagnostic confusion among treating physicians. Hence, characterizing the prevalence and clinical accompaniments of these other tremors is of value. Surprisingly, there are few data on the prevalence of rest tremor in ET patients, and even fewer data on the clinical correlates of such tremor. Methods 831 patients in four distinct settings (population, genetics study, study of environmental epidemiology, brain bank) underwent a detailed videotaped neurological examination that was reviewed by a senior movement disorders neurologist. Rest tremor was evaluated in several positions (seated, standing, lying down). Results The prevalence of rest tremor while seated or standing was lowest in the population-based setting (1.9%), highest in the brain bank study (46.4%), and intermediate in the remaining two settings (9.6% and 14.7%, respectively). Rest tremor was restricted to the arms and was not observed in the legs. Rest tremor was associated with older age, longer disease duration (in some studies), greater tremor severity and, to some extent, the presence of cranial tremors. Conclusions Rest tremor can be a common clinical feature of ET. Its prevalence is highly dependent on the setting in which patients are evaluated, ranging from as low as 1% to nearly 50%. Rest tremor seems to emerge as a clinical feature with advancing disease. The anatomical substrates for this type of tremor remain unknown at present. PMID:25786561

  12. Differences in striatal dopamine transporter density between tremor dominant and non-tremor Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kaasinen, Valtteri; Kinos, Maija; Joutsa, Juho [University of Turku and Turku University Hospital, Division of Clinical Neurosciences, Turku (Finland); University of Turku and Turku University Hospital, Turku PET Centre, Turku (Finland); Seppaenen, Marko [University of Turku and Turku University Hospital, Turku PET Centre, Turku (Finland); University of Turku and Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku (Finland); Noponen, Tommi [University of Turku and Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku (Finland)

    2014-10-15

    Parkinson's disease (PD) can manifest with a tremor-dominant or a non-tremor (akinetic-rigid) phenotype. Although the tremor-dominant subtype may show a better prognosis, there is limited information on the phenotypic differences regarding the level of striatal dopamine transmission. The present study investigated striatal dopamine transporter (DAT) binding characteristics in a large sample of patients with and without tremor. [{sup 123}I]FP-CIT SPECT scans of 231 patients with a clinical diagnosis of PD and abnormal FP-CIT binding (157 with tremor, 74 without tremor) and 230 control patients with normal FP-CIT binding (148 with tremor, 82 without tremor) were analysed using an automated region-of-interest analysis of the scans (BRASS). Specific striatal binding ratios were compared between phenotypes and groups using age, sex, and symptom duration, predominant side of symptoms, dopaminergic medications and scanner as covariates. Patients with PD had 28.1 - 65.0 % lower binding in all striatal regions compared to controls (p < 0.001). The mean FP-CIT caudate nucleus uptake and the left caudate nucleus uptake were higher in PD patients with tremor than in PD patients without tremor (mean 9.0 % higher, left 10.5 % higher; p < 0.05), whereas there were no differences between tremor and non-tremor control patients. No significant effects of tremor on DAT binding were observed in the anterior or posterior putamen. The motor phenotype is associated with the extent of caudate dopamine terminal loss in PD, as dopamine function is relatively more preserved in tremor patients. Symptom type is related to caudate dopamine function only in association with Parkinsonian dopaminergic degeneration, not in intact dopamine systems in patients with non-PD tremor. (orig.)

  13. Prevalence and correlates of rest tremor in essential tremor: cross-sectional survey of 831 patients across four distinct cohorts.

    Science.gov (United States)

    Louis, E D; Hernandez, N; Michalec, M

    2015-06-01

    Essential tremor (ET) is amongst the most commonly encountered neurological disorders. Its hallmark feature is kinetic tremor. However, other tremors may also occur in ET patients, creating considerable diagnostic confusion amongst treating physicians. Hence, characterizing the prevalence and clinical accompaniments of these other tremors is of value. Surprisingly, there are few data on the prevalence of rest tremor in ET patients, and even fewer data on the clinical correlates of such tremor. Eight hundred and thirty-one patients in four distinct settings (population, genetics study, study of environmental epidemiology, brain bank) underwent a detailed videotaped neurological examination that was reviewed by a senior movement disorders neurologist. Rest tremor was evaluated in several positions (seated, standing, lying down). The prevalence of rest tremor whilst seated or standing was lowest in the population-based setting (1.9%), highest in the brain bank study (46.4%) and intermediate in the remaining two settings (9.6% and 14.7%, respectively). Rest tremor was restricted to the arms and was not observed in the legs. Rest tremor was associated with older age, longer disease duration (in some studies), greater tremor severity and, to some extent, the presence of cranial tremors. Rest tremor can be a common clinical feature of ET. Its prevalence is highly dependent on the setting in which patients are evaluated, ranging from as low as 1% to nearly 50%. Rest tremor seems to emerge as a clinical feature with advancing disease. The anatomical substrates for this type of tremor remain unknown at present. © 2015 EAN.

  14. Deterministic properties of mine tremor aftershocks

    CSIR Research Space (South Africa)

    Kgarume, TE

    2010-10-01

    Full Text Available Mine tremor aftershock sequences from two deep mines in the Far West Rand goldfield, South Africa, were analysed in order to determine the influence of geological and mining parameters on the risk posed by aftershocks. Mainshocks were stacked...

  15. The effects of isometric resistance training on stretch reflex induced tremor in the knee extensor muscles.

    Science.gov (United States)

    Durbaba, Rade; Cassidy, Angela; Budini, Francesco; Macaluso, Andrea

    2013-06-15

    This study examines the effect of 4 wk of high-intensity isometric resistance training on induced tremor in knee extensor muscles. Fourteen healthy volunteers were assigned to either the training group (n = 7) or the nontraining control group (n = 7). Induced tremor was assessed by measuring force fluctuations during anisometric contractions against spring loading, whose compliance was varied to allow for preferential activation of the short or long latency stretch reflex components. Effects of high-intensity isometric resistance training on induced tremor was assessed under two contraction conditions: relative force matching, where the relative level of activity was equal for both pre- and post-training sessions, set at 30% maximum voluntary contraction (MVC), and absolute force matching, where the level of activity was set to 30% pretrained MVC. The training group experienced a 26.5% increase in MVC in contrast to the 0.8% for the control group. For relative force-matching contractions, induced tremor amplitude and frequency did not change in either the training or control group. During absolute force-matching contractions, induced tremor amplitude was decreased by 37.5% and 31.6% for the short and long components, respectively, with no accompanying change in frequency, for the training group. No change in either measure was observed in the control group for absolute force-matching contractions. The results are consistent with high-intensity isometric resistance training induced neural changes leading to increased strength, coupled with realignment of stretch reflex automatic gain compensation to the new maximal force output. Also, previous reported reductions in anisometric tremor following strength training may partly be due to changed stretch reflex behavior.

  16. Differential effects of alpha-adrenoceptor blockade on essential, physiological and isoprenaline-induced tremor: evidence for a central origin of essential tremor.

    OpenAIRE

    Abila, B; Wilson, J F; Marshall, R W; Richens, A

    1985-01-01

    Intravenous thymoxamine reduced the power of essential tremor but increased that of physiological and isoprenaline-induced tremor. These findings indicate that essential and physiological tremor have dissimilar pathophysiological mechanisms. They also suggest that central adrenergic mechanisms are involved in the pathophysiology of essential tremor and that isoprenaline-induced tremor is not a good model of essential tremor. Furthermore, alpha-adrenoceptor blockers may be a useful therapy for...

  17. Tectonic tremor activity associated with teleseismic and nearby earthquakes

    Science.gov (United States)

    Chao, K.; Obara, K.; Peng, Z.; Pu, H. C.; Frank, W.; Prieto, G. A.; Wech, A.; Hsu, Y. J.; Yu, C.; Van der Lee, S.; Apley, D. W.

    2016-12-01

    Tectonic tremor is an extremely stress-sensitive seismic phenomenon located in the brittle-ductile transition section of a fault. To better understand the stress interaction between tremor and earthquake, we conduct the following studies: (1) search for triggered tremor globally, (2) examine ambient tremor activities associated with distant earthquakes, and (3) quantify the temporal variation of ambient tremor activity before and after nearby earthquakes. First, we developed a Matlab toolbox to enhance the searching of triggered tremor globally. We have discovered new tremor sources in the inland faults in Kyushu, Kanto, and Hokkaido in Japan, southern Chile, Ecuador, and central Colombia in South America, and in South Italy. Our findings suggest that tremor is more common than previously believed and indicate the potential existence of ambient tremor in the triggered tremor active regions. Second, we adapt the statistical analysis to examine whether the long-term ambient tremor rate may affect by the dynamic stress of teleseismic earthquakes. We analyzed the data in Nankai, Hokkaido, Cascadia, and Taiwan. Our preliminary results did not show an apparent increase of ambient tremor rate after the passing of surface waves. Third, we quantify temporal changes in ambient tremor activity before and after the occurrence of local earthquakes under the southern Central Range of Taiwan with magnitudes of >=5.5 from 2004 to 2016. For a particular case, we found a temporal variation of tremor rate before and after the 2010/03/04 Mw6.3 earthquake, located about 20 km away from the active tremor source. The long-term increase in the tremor rate after the earthquake could have been caused by an increase in static stress following the mainshock. For comparison, clear evidence from seismic and GPS observations indicate a short-term increase in the tremor rate a few weeks before the mainshock. The increase in the tremor rate before the mainshock could correlate with stress changes

  18. Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence.

    Science.gov (United States)

    Cerasa, Antonio; Quattrone, Aldo

    2016-06-01

    Essential tremor (ET) is the most common pathological tremor disorder in the world, and post-mortem evidence has shown that the cerebellum is the most consistent area of pathology in ET. In the last few years, advanced neuroimaging has tried to confirm this evidence. The aim of the present review is to discuss to what extent the evidence provided by this field of study may be generalised. We performed a systematic literature search combining the terms ET with the following keywords: MRI, VBM, MRS, DTI, fMRI, PET and SPECT. We summarised and discussed each study and placed the results in the context of existing knowledge regarding the cerebellar involvement in ET. A total of 51 neuroimaging studies met our search criteria, roughly divided into 19 structural and 32 functional studies. Despite clinical and methodological differences, both functional and structural imaging studies showed similar findings but without defining a clear topography of neurodegeneration. Indeed, the vast majority of studies found functional and structural abnormalities in several parts of the anterior and posterior cerebellar lobules, but it remains to be established to what degree these neural changes contribute to clinical symptoms of ET. Currently, advanced neuroimaging has confirmed the involvement of the cerebellum in pathophysiological processes of ET, although a high variability in results persists. For this reason, the translation of this knowledge into daily clinical practice is again partially limited, although new advanced multivariate neuroimaging approaches (machine-learning) are proving interesting changes of perspective.

  19. Evaluation of precipitates used in strainer head loss testing: Part II. Precipitates by in situ aluminum alloy corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, Chi Bum, E-mail: bahn@anl.go [Argonne National Laboratory, Lemont, IL 60439 (United States); Kasza, Ken E.; Shack, William J.; Natesan, Ken [Argonne National Laboratory, Lemont, IL 60439 (United States); Klein, Paul [The United States Nuclear Regulatory Commission, Rockville, MD 20852 (United States)

    2011-05-15

    Graphical abstract: Display Omitted Research highlights: Sump strainer head loss testing to evaluate chemical effects. Aluminum hydroxide precipitates by in situ Al alloy corrosion caused head loss. Intermetallic particles released from Al alloy can also cause significant head loss. When evaluating Al effect on head loss, intermetallics should be considered. - Abstract: Vertical loop head loss tests were performed with 6061 and 1100 aluminum (Al) alloy plates immersed in borated solution at pH = 9.3 at room temperature and 60 {sup o}C. The results suggest that the potential for corrosion of an Al alloy to result in increased head loss across a glass fiber bed may depend on its microstructure, i.e., the size distribution and number density of intermetallic particles that are present in Al matrix and FeSiAl ternary compounds, as well as its Al release rate. Per unit mass of Al removed from solution, the WCAP-16530 aluminum hydroxide (Al(OH){sub 3}) surrogate was more effective in increasing head loss than the Al(OH){sub 3} precipitates formed in situ by corrosion of Al alloy. However, in choosing a representative amount of surrogate for plant specific testing, consideration should be given to the potential for additional head losses due to intermetallic particles and the apparent reduction in the effective solubility of Al(OH){sub 3} when intermetallic particles are present.

  20. [The use of neuromodulation for the treatment of tremor].

    Science.gov (United States)

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Tremor may be a disabling disorder and pharmacologic treatment is the first-line therapy for these patients. Nevertheless, this treatment may lead to a satisfactory tremor reduction in only 50% of patients with essential tremor. Thalamotomy was the treatment of choice for tremor refractory to medical therapy until deep brain stimulation (DBS) of the ventral intermedius nucleus (Vim) of the thalamus has started being used. Nowadays, thalamotomy is rarely performed. This article is a non-systematic review of the indications, results, programming parameters and surgical technique of DBS of the Vim for the treatment of tremor. In spite of the fact that it is possible to achieve similar clinical results using thalamotomy or DBS of the Vim, the former causes more adverse effects than the latter. Furthermore, DBS can be used bilaterally, whereas thalamotomy has a high risk of causing disartria when it is performed in both sides. DBS of the Vim achieved an adequate tremor improvement in several series of patients with tremor caused by essential tremor, Parkinson's disease or multiple sclerosis. Besides the Vim, there are other targets, which are being used by some authors, such as the zona incerta and the prelemniscal radiations. DBS of the Vim is a useful treatment for disabling tremor refractory to medical therapy. It is essential to carry out an accurate patient selection as well as to use a proper surgical technique. The best stereotactic target for tremor is still unknown, although the Vim is the most used one.

  1. Cerebral causes and consequences of parkinsonian resting tremor: a tale of two circuits?

    NARCIS (Netherlands)

    Helmich, R.C.G.; Hallett, M.; Deuschl, G.; Toni, I.; Bloem, B.R.

    2012-01-01

    Tremor in Parkinson's disease has several mysterious features. Clinically, tremor is seen in only three out of four patients with Parkinson's disease, and tremor-dominant patients generally follow a more benign disease course than non-tremor patients. Pathophysiologically, tremor is linked to

  2. [Topiramate in the treatment of essential tremor].

    Science.gov (United States)

    Zalialova, Z A; Latypova, G R

    2008-01-01

    Therapeutic efficacy of topiramate in essential tremor (ET) was assessed in comparison with propranolol in two groups which included 24 and 20 patients, respectively, aged from 21 to 83 years (mean age 53 years). Along with clinical examination, a number of scales: Clinical rating scale for tremor, scale of functional disturbances and Visual-analogous scale have been administered. The efficacy of topiramate was comparable to that of propranolol in 83% and 75% cases, respectively. However topiramate has some therapeutic advantages compared to propranolol; it may be prescribed for all clinical forms regardless of sex (its efficacy is higher in women), age and illness duration, both in earlier and later onset, familial and sporadic variants of ET (propranolol is more effective in patients with family history of ET). Moreover, in contrast to propranolol, topiramate may be prescribed to patients with predisposition to arterial hypertension and bradicardia, bronchial spasms of diabetes mellitus and heart rhythm disturbances.

  3. Brittle and ductile friction and the physics of tectonic tremor

    Science.gov (United States)

    Daub, Eric G.; Shelly, David R.; Guyer, Robert A.; Johnson, P.A.

    2011-01-01

    Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly constrained, limiting our basic understanding of tremor and its relation to earthquakes. We combine field and laboratory observations with a physical friction model comprised of brittle and ductile components, and use the model to provide constraints on the friction and stress state in the lower crust. A phase diagram is constructed that characterizes under what conditions all faulting behaviors occur, including earthquakes, tremor, silent transient slip, and steady sliding. Our results show that tremor occurs over a range of ductile and brittle frictional strengths, and advances our understanding of the physical conditions at which tremor and earthquakes take place.

  4. Task-specific writing tremor: clinical phenotypes, progression, treatment outcomes, and proposed nomenclature.

    Science.gov (United States)

    Ondo, William G; Satija, Pankaj

    2012-02-01

    Task-specific tremor diagnoses remain controversial. We evaluated 56 subjects seen with writing tremor. The diagnosis was made if there was a clear history of exclusive tremor while writing for at least 3 years before noticing tremor in any other scenario and the continued presence of writing tremor as the most prominent aspect of their tremor disorder on examination. The age of tremor onset was 47.2 ± 18.0 years (73.2% male). Ethnic backgrounds were Caucasian (68.4%), African (23.2%), Hispanic (5.2%), and Asian/Indian (3.3%), and 44% reported any tremor in a first degree relative. Writing tremor often progressed to other task-specific tremors or rest tremor but not to immediate postural tremor, as usually seen in essential tremor. The other tremor provoking scenarios were eating/drinking (14), brushing teeth/shaving/make-up (5), typing (2), suture removal (1), and drafting (1) and occurred a mean of 7.5 years after the onset of writing tremor. Fourteen developed a "rest" (true rest or crescendo) tremor but only 2 of these met clinical criteria for Parkinson's disease. Pharmacologic treatments of writing tremor, including with ethanol, were generally poor, whereas deep brain stimulation of the ventral intermediate (VIM) thalamus was successful. Compared with patients with "classic" essential tremor in our clinic, writing tremor patients were more likely African, more likely male, had an older age of onset, a lower likelihood of familial tremor, and were more refractory to tremor medications and ethanol. This supports segregation between task-specific tremor and essential tremor but does not support the specific diagnosis of "writing tremor" because many patients progress to tremor with other tasks.

  5. Hilbert-Huang transform based instrumental assessment of intention tremor in multiple sclerosis

    Science.gov (United States)

    Carpinella, Ilaria; Cattaneo, Davide; Ferrarin, Maurizio

    2015-08-01

    Objective. This paper describes a method to extract upper limb intention tremor from gyroscope data, through the Hilbert-Huang transform (HHT), a technique suitable for the study of nonlinear and non-stationary processes. The aims of the study were to: (i) evaluate the method’s ability to discriminate between healthy controls and MS subjects; (ii) validate the proposed procedure against clinical tremor scores assigned using Fahn’s tremor rating scale (FTRS); and (iii) compare the performance of the HHT-based method with that of linear band-pass filters. Approach. HHT was applied on gyroscope data collected on 20 MS subjects and 13 healthy controls (CO) during finger-to-nose tests (FNTs) instrumented with an inertial sensor placed on the hand. The results were compared to those obtained after traditional linear filtering. The tremor amplitude was quantified with instrumental indexes (TIs) and clinical FTRS ratings. Main results. The TIs computed after HHT-based filtering discriminated between CO and MS subjects with clinically-detected intention tremor (MS_T). In particular, TIs were significantly higher in the final part of the movement (TI2) with respect to the first part (TI1), and, for all components (X, Y, Z), MST showed a TI2 significantly higher than in CO subjects. Moreover, the HHT detected subtle alterations not visible from clinical ratings, as TI2 (Z-component) was significantly increased in MS subjects without clinically-detected tremor (MS_NT). The method’s validity was demonstrated by significant correlations between clinical FTRS scores and TI2 related to X (rs = 0.587, p = 0.006) and Y (rs = 0.682, p < 0.001) components. Contrarily, fewer differences among the groups and no correlation between instrumental and clinical indexes emerged after traditional filtering. Significance. The present results supported the use of the HHT-based procedure for a fully-automated quantitative and objective measure of intention tremor in MS, which can overcome

  6. Accuracy of forecast of mine tremors location

    Energy Technology Data Exchange (ETDEWEB)

    Jan Drzewieck [Central Mining Institute, Katowice (Poland)

    2009-09-15

    The Upper Silesian Coal Basin is one of the most active mining areas in the world in respect of seismicity. Underground mining in this area takes place in a special environment with a high degree of risk of unpredictable event occurrence. Especially dangerous are phenomena that occur during the extraction of deposits at great depths in the environment of compact rocks. Deep underground mining violates the balance of these rocks and induces dynamic phenomena at the longwall life (in terms of distance) referred to as mine tremors. The sources of these tremors are located in layers characterised by high strength, especially in thick sandstone strata occurring in the roof of the mined seam. In the paper a discussion is presented about the influence of mining intensity (longwall face speed) on the location of mine tremor sources, both in the direction of longwall life (in terms of distance) and towards the surface. The presented material has been prepared based on the results of tests and measurements carried out at the Central Mining Institute. 8 refs., 5 figs.

  7. Locating tremor using stacked products of correlations

    Science.gov (United States)

    Li, Ka Lok; Sadeghisorkhani, Hamzeh; Sgattoni, Giulia; Gudmundsson, Olafur; Roberts, Roland

    2017-04-01

    We introduce a back-projection method to locate tremor sources using products of cross-correlation envelopes of time series between seismic stations. For a given subset of n stations, we calculate the (n - 1)th-order product of cross-correlation envelopes and we stack the back-projected products over combinations of station subsets. We show that compared to existing correlation methods and for realistic signal and noise characteristics, this way of combining information can significantly reduce the effects of correlated (spurious or irrelevant signals) and uncorrelated noise. Each back-projected product constitutes an individual localized estimate of the source locations, as opposed to a hyperbola for the existing correlation techniques, assuming a uniform velocity in two dimensions. We demonstrate the method with synthetic examples and a real-data example from tremor at Katla Volcano, Iceland, in July 2011. Despite very complex near-surface structure, including strong topography and thick ice cover, the method appears to produce robust estimates of tremor location.

  8. Stereotactic radiosurgery for medically refractory multiple sclerosis-related tremor.

    Science.gov (United States)

    Raju, Sudesh S; Niranjan, Ajay; Monaco, Edward A; Flickinger, John C; Lunsford, L Dade

    2017-06-30

    OBJECTIVE Multiple sclerosis (MS) is a neurodegenerative disease that can lead to severe intention tremor in some patients. In several case reports, conventional radiotherapy has been reported to possibly exacerbate MS. Radiosurgery dramatically limits normal tissue irradiation to potentially avoid such a problem. Gamma Knife thalamotomy (GKT) has been established as a minimally invasive technique that is effective in treating essential tremor and Parkinson's disease-related tremor. The goal in this study was to analyze the outcomes of GKT in patients suffering from medically refractory MS-related tremor. METHODS The authors retrospectively studied the outcomes of 15 patients (mean age 46.5 years) who had undergone GKT over a 15-year period (1998-2012). Fourteen patients underwent GKT at a median maximum dose of 140 Gy (range 130-150 Gy) using a single 4-mm isocenter. One patient underwent GKT at a dose of 140 Gy delivered via two 4-mm isocenters (3 mm apart). The posteroinferior region of the nucleus ventralis intermedius (VIM) was the target for all GKTs. The Fahn-Tolosa-Marin clinical tremor rating scale was used to evaluate tremor, handwriting, drawing, and drinking. The median time to the last follow-up was 39 months. RESULTS After GKT, 13 patients experienced tremor improvement on the side contralateral to surgery. Four patients noted tremor arrest at a median of 4.5 months post-GKT. Seven patients had excellent tremor improvement and 6 had good tremor improvement. Four patients noted excellent functional improvement, 8 noted good functional improvement, and 1 noted satisfactory functional improvement. Three patients experienced diminished tremor relief at a median of 18 months after radiosurgery. Two patients experienced temporary adverse radiation effects. Another patient developed a large thalamic cyst 60 months after GKT, which was successfully managed with Ommaya reservoir placement. CONCLUSIONS Gamma Knife thalamotomy was found to be a minimally

  9. The long-term outcome of orthostatic tremor.

    Science.gov (United States)

    Ganos, Christos; Maugest, Lucie; Apartis, Emmanuelle; Gasca-Salas, Carmen; Cáceres-Redondo, María T; Erro, Roberto; Navalpotro-Gómez, Irene; Batla, Amit; Antelmi, Elena; Degos, Bertrand; Roze, Emmanuel; Welter, Marie-Laure; Mestre, Tiago; Palomar, Francisco J; Isayama, Reina; Chen, Robert; Cordivari, Carla; Mir, Pablo; Lang, Anthony E; Fox, Susan H; Bhatia, Kailash P; Vidailhet, Marie

    2016-02-01

    Orthostatic tremor is a rare condition characterised by high-frequency tremor that appears on standing. Although the essential clinical features of orthostatic tremor are well established, little is known about the natural progression of the disorder. We report the long-term outcome based on the largest multicentre cohort of patients with orthostatic tremor. Clinical information of 68 patients with clinical and electrophysiological diagnosis of orthostatic tremor and a minimum follow-up of 5 years is presented. There was a clear female preponderance (76.5%) with a mean age of onset at 54 years. Median follow-up was 6 years (range 5-25). On diagnosis, 86.8% of patients presented with isolated orthostatic tremor and 13.2% had additional neurological features. At follow-up, seven patients who initially had isolated orthostatic tremor later developed further neurological signs. A total 79.4% of patients reported worsening of orthostatic tremor symptoms. These patients had significantly longer symptom duration than those without reported worsening (median 15.5 vs 10.5 years, respectively; p=0.005). There was no change in orthostatic tremor frequency over time. Structural imaging was largely unremarkable and dopaminergic neuroimaging (DaTSCAN) was normal in 18/19 cases. Pharmacological treatments were disappointing. Two patients were treated surgically and showed improvement. Orthostatic tremor is a progressive disorder with increased disability although tremor frequency is unchanged over time. In most cases, orthostatic tremor represents an isolated syndrome. Drug treatments are unsatisfactory but surgery may hold promise. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  10. A Quaternion Weighted Fourier Linear Combiner for Modeling Physiological Tremor.

    Science.gov (United States)

    Adhikari, Kabita; Tatinati, Sivanagaraja; Ang, Wei Tech; Veluvolu, Kalyana C; Nazarpour, Kianoush

    2016-11-01

    This paper offers a new approach to model physiological tremor aiming at attenuating undesired vibrations of the tip of microsurgical instruments. Several tremor modeling algorithms, such as the weighted Fourier linear combiner (wFLC), have proved effective. They, however, treat the three-dimensional (3-D) tremor signal as three independent 1-D signals in the x-, y-, and z-axes. In addition, the force f by which a surgeon holds the instrument has never been taken into account in modeling. Hence, conventional algorithms are inherently blind to any potential multidimensional couplings. We first show that there exists statistically significant subject- and task-dependent coherence between data in the x-, y-, z -, and f-axes. We hypothesize that a filter that models the tremor in 4-D ( x , y, z, and f ) yields a more accurate model of tremor. We, therefore, developed a quaternion version of the wFLC algorithm and termed it QwFLC. We tested the proposed QwFLC algorithm with real physiological tremor data that were recorded from five novice subjects and four experienced microsurgeons. Although compared to wFLC, QwFLC requires six times larger computational resources, we showed that QwFLC can improve the modeling by up to 67% and that the improvement is proportional to the total coherence between the tremor in xyz and the force signal. By taking into account interactions of the 3-D tremor and the force data, the tremor modeling performance enhances significantly.

  11. Towards closed-loop deep brain stimulation: decision tree-based essential tremor patient's state classifier and tremor reappearance predictor.

    Science.gov (United States)

    Shukla, Pitamber; Basu, Ishita; Tuninetti, Daniela

    2014-01-01

    Deep Brain Stimulation (DBS) is a surgical procedure to treat some progressive neurological movement disorders, such as Essential Tremor (ET), in an advanced stage. Current FDA-approved DBS systems operate open-loop, i.e., their parameters are unchanged over time. This work develops a Decision Tree (DT) based algorithm that, by using non-invasively measured surface EMG and accelerometer signals as inputs during DBS-OFF periods, classifies the ET patient's state and then predicts when tremor is about to reappear, at which point DBS is turned ON again for a fixed amount of time. The proposed algorithm achieves an overall accuracy of 93.3% and sensitivity of 97.4%, along with 2.9% false alarm rate. Also, the ratio between predicted tremor delay and the actual detected tremor delay is about 0.93, indicating that tremor prediction is very close to the instant where tremor actually reappeared.

  12. Shallow micro low-frequency tremor before the Tohoku-Oki earthquake

    Science.gov (United States)

    Katakami, Satoshi; Ito, Yoshihiro; Ohta, Kazuaki; Hino, Ryota; Suzuki, Syuichi; Shinohara, Masanao

    2017-04-01

    Slow earthquake activity is one of the important phenomena to understand slip behavior in the shallower part of the subduction zone, especially to understand the generation of tsunami earthquakes. Recently, SSEs and low-frequency tremor have been observed near the trench by using ocean bottom observations, and these have been located in the updip portion of a coseismic slip area [Wallace et al., 2016; Yamashita et al., 2015]. In addition, Ito et al. [2015] observed tremor sequences from the excitation of ambient noise amplitude, accompanied with SSE in the source area of the Tohoku-Oki earthquake's mainshock. However, the signals observed within these sequences showed very weak amplitude and were observed at only one station, nearest to the Japan Trench. Here, we report on our detection of micro low-frequency tectonic tremor (mLFT) activity prior to the 2011 Tohoku-Oki earthquake near the Japan Trench by using modified frequency scanning method (mFSM) as applied to ocean bottom seismometers (OBSs) . The original frequency scanning method [Sit et al., 2012] proposed a tremor detection method of calculating envelope waveform ratios through different bandpass filters of broadband data in the Cascadia margin. We modified this analysis for short period OBS seismic data recorded at 17 OBSs deployed in an area near the trench axis offshore Miyagi Prefecture, northeast Japan. Three bandpass filters of 2-4 Hz, 10-20 Hz, and 0.5-1.0 Hz, corresponding to the dominant frequency band of tremors, local earthquakes, and ocean noise, respectively, were applied to the OBS records for a period between November 19, 2010 and March 9, 2011. This duration is the same as the deployment period of TJT2 station which is located nearest to the Japan Trench, and is also before the largest foreshock of the Tohoku-Oki earthquake. The results of applying the mFSM show three major tremor sequences, suggesting tremor activity in the shallowest part of the subduction zone. The sequences agree with

  13. Long-term tremor therapy for Parkinson and essential tremor with sensor-guided botulinum toxin type A injections.

    Science.gov (United States)

    Samotus, Olivia; Lee, Jack; Jog, Mandar

    2017-01-01

    Current pharmacological agents used to treat Parkinson disease (PD) tremor and essential tremor (ET) provide suboptimal benefit and are commonly associated with significant adverse effects. Botulinum toxin type A (BoNT-A) has been shown to be effective for wrist tremor though functionally bothersome muscle weakness frequently occurs. This is the longest study to date demonstrating that BoNT-A therapy coupled with kinematic guidance can provide efficacious outcomes for upper limb tremor with minimized unwanted weakness. A total of 28 PD and 24 ET participants with bothersome, disabling tremor, received six serial BoNT-A treatments every 16 weeks starting at week 0 with a follow-up visit 6 weeks following a treatment, totaling 96 weeks. Clinical scales, including Fahn-Tolosa-Marin tremor rating scale (FTM), and sensor-based tremor assessments were conducted at each visit. Kinematics was utilized to identify which arm muscles contributed to the tremulous movements and the experienced injector used clinical expertise in determining BoNT-A dosages. Following BoNT-A treatment, clinical ratings of tremor severity and functional ability (FTM) showed significant improvements following the first treatment which was maintained up to week 96 in PD and ET. Kinematics detected a significant reduction in PD and ET tremor amplitudes by 70% and 76% over the treatment course, respectively. By objectively distinguishing tremulous muscles and tremor severity, adverse effects were limited to mild perceived weakness by participants in injected muscles during follow-ups. Following the fourth treatment, BoNT-A dosages in flexor and extensor wrist muscles and biceps were reduced for those experiencing residual weakness which ultimately did not interfere with tremor relief or arm function. Kinematics is an objective method that can aid clinicians in assessing and determining optimal BoNT-A parameters to alleviate both PD and ET tremor. BoNT-A injections are tolerable and effective when

  14. Comparative Burden of Subclinical Tremor in a Cohort of Normal Individuals Stratified by Familial Risk for Essential Tremor.

    Science.gov (United States)

    Louis, Elan D; Meyers, James H; Badejo, Olufunmilayo M; Cristal, Ashley D; Hickman, Ruby; Factor-Litvak, Pam

    2018-01-16

    The burden of mild (i.e., subclinical) tremor within essential tremor (ET) families is not fully understood. We assessed the burden of mild tremor in a cohort of 287 adults, none of whom reported tremor or were diagnosed with ET. We recruited adults in 2 groups based on the familial risk for ET: 244 high-risk individuals (i.e., reporting one or more first-degree relative with ET) and 43 low-risk individuals (i.e., reporting no relatives with ET). Tremor was objectively assessed on 4 hand-drawn spirals (total spiral score = 0-12). Mild tremor was defined using 3 different cut points. The prevalence rates of mild tremor among high-risk individuals ranged from 41.4 to 98.4% and were highly dependent on the cut point. Above a certain threshold (i.e., a total spiral score ≥5), 1-in-5 (i.e., 19.7%) high-risk individuals exhibited mild tremor, whereas no low-risk individuals did. High-risk individuals were 3.09-4.50 times more likely than low-risk individuals to exhibit mild tremor. The burden of ET extends beyond the boundaries of the clinically defined disease, and partially expressed forms of ET are abundant in ET families. This fact greatly complicates gene-finding studies and epidemiological studies whose goal is to detect disease-linked associations. © 2018 S. Karger AG, Basel.

  15. Dynamic modeling of the neck muscles during horizontal head movement. Part II: Model construction in Pro/Engineer.

    Science.gov (United States)

    Haapala, Stephenie A; Enderle, John D

    2003-01-01

    This paper describes the next phase of research on a parametric model of the head-neck system for dynamic simulation of horizontal head rotation. A skull has been imported into Pro/Engineer software and has been assigned mass properties such as density, surface area and moments of inertia. The origin of a universal coordinate system has been located at the center of gravity of the T1 vertebrae. Identification of this origin allows insertion and attachment points of the sternocleidomastoid (SCOM) and splenius capitis to be located. An assembly has been created, marking the location of both muscle sets. This paper will also explore the obstacles encountered when working with an imported feature in Pro/E and attempts to resolve some of these issues. The goal of this work involves the creation of a 3D homeomorphic saccadic eye and head movement system.

  16. Self-reported physical activity in essential tremor: Relationship with tremor, balance, and cognitive function.

    Science.gov (United States)

    Louis, Elan D; Collins, Kathleen; Rohl, Brittany; Morgan, Sarah; Robakis, Daphne; Huey, Edward D; Cosentino, Stephanie

    2016-07-15

    Physical inactivity may be the result of medical comorbidities. Inactivity itself may also lead to important health consequences, especially in older patients. Essential tremor (ET) patients may have a variety of physical and cognitive problems that could detrimentally impact on level of physical activity. Yet, to our knowledge, there have been no studies of physical activity in these patients. Self-reported physical activity was assessed using the Physical Activity Scale for the Elderly (PASE) in 100 ET cases (mean age 80.5years) enrolled in a clinical study. Additional clinical measures were the total tremor score, Montreal Cognitive Assessment (MOCA) score and number of steps taken off of the straight line during tandem gait (a measure of balance). Lower PASE score was associated with older age, more tandem gait difficulty, higher total tremor score and lower MOCA score (all pphysical activity. Several of the motor features of ET (tremor and imbalance) are independently associated with reductions in level of physical activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Evaluation of precipitates used in strainer head loss testing : Part II. precipitates by in-situ aluminum alloy corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, C.; Kasza, K. E.; Shack, W. J.; Natesan, K. (Nuclear Engineering Division)

    2011-05-01

    Vertical loop head loss tests were performed with 6061 and 1100 aluminum (Al) alloy plates immersed in borated solution at pH = 9.3 at room temperature and 60 C. The results suggest that the potential for corrosion of an Al alloy to result in increased head loss across a glass fiber bed may depend on its microstructure, i.e., the size distribution and number density of intermetallic particles that are present in Al matrix and FeSiAl ternary compounds, as well as its Al release rate. Per unit mass of Al removed from solution, the WCAP-16530 aluminum hydroxide (Al(OH){sub 3}) surrogate was more effective in increasing head loss than the Al(OH)3 precipitates formed in situ by corrosion of Al alloy. However, in choosing a representative amount of surrogate for plant specific testing, consideration should be given to the potential for additional head losses due to intermetallic particles and the apparent reduction in the effective solubility of Al(OH){sub 3} when intermetallic particles are present.

  18. Seismicity and tectonic tremor accompany the 2014 Gisborne Slow Slip Event: Insights from the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) Experiment, New Zealand

    Science.gov (United States)

    Todd, E. K.; Schwartz, S. Y.; Sheehan, A. F.; Mochizuki, K.

    2016-12-01

    The northern Hikurangi Margin is host to some of the shallowest slow slip events (SSEs) in the world. Slow slip offshore Gisborne, New Zealand has been observed at depths as shallow as 2 km and may extend all the way to the trench. Gisborne SSEs are accompanied by tectonic tremor and increased levels of seismicity, but this activity has only been observed at the onshore, downdip edge of the slow slip patch. Between May 2014 and June 2015, 24 absolute pressure gauges, 10 broadband seismometers, and 5 short period seismometers were deployed offshore Gisborne along the east coast of the North Island of New Zealand as part of the HOBITSS Experiment. These instruments were in place during a large Gisborne SSE (peak slip 20 cm) in September and October 2014. Using this new ocean-derived dataset in conjunction with existing land data from the New Zealand National Seismograph Network operated by GeoNet (http://geonet.org.nz), we present an in-depth, systematic investigation of tremor and microseismicity associated with this shallow Gisborne SSE to further examine the spatial heterogeneity of slip processes on the shallow megathrust. Tremor and earthquakes are collocated with the geodetically inverted slow slip patch with tremor occurring offshore and earthquakes concentrated downdip of a shallowly subducted seamount near the region of peak displacement during the SSE. This discovery indicates that the region of the megathrust slipping in these SSEs is capable of multiple types of slip and understanding the spatiotemporal relationships between these strain release modes has implications for local seismic hazards.

  19. Minimising tremor in a joystick using fuzzy logic

    NARCIS (Netherlands)

    van der Zwaag, B.J.; Corbett, Dan; Jain, Lakhmi; Kappen, H.J.; Duin, R.P.W.; Krose, B.J.A.; Segeth, W.

    We have designed and built a fuzzy logic controller which minimises the effect of Multiple Sclerosis (MS) hand tremors. The aim of our project has been to give people with Multiple Sclerosis better control of an electronic wheelchair by removing tremors from the joystick signal. The system

  20. Capturing hand tremors with a fuzzy logic wheelchair joystick controller

    NARCIS (Netherlands)

    van der Zwaag, B.J.; Corbett, Dan

    We have designed and built a fuzzy logic wheelchair controller which minimizes the effect of Multiple Sclerosis and tremors. The aim of our project has been to give people with Multiple Sclerosis better control of an electric wheelchair by removing tremors from the joystick signal. The system

  1. Fragile X-associated tremor/ataxia syndrome.

    Science.gov (United States)

    Hoem, Gry; Koht, Jeanette

    2017-10-31

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is a hereditary neurodegenerative disorder caused by a mutation on the X chromosome. The major signs and symptoms are tremor, ataxia and parkinsonism. Up to one in 2 000 persons over 50 years of age will develop the syndrome. There is reason to believe that too few individuals in Norway undergo testing for this condition.

  2. [Primary orthostatic tremor: slow harmonic component as responsible of inestability].

    Science.gov (United States)

    Cano, J; Catalán, B; Ibáñez, R; Gudín, M; Hernández, A; Vaamonde, J

    2001-01-01

    Orthostatic tremor (OT) is clinically defined as a tremor of the lower limbs and trunk on walking. It bears a significant functional impairement. Although the term orthostatic tremor was first used by Heilman in 1984, Pazzaglia et al had previously described some cases in 1970. Despite the fact that the pathophysiology of this entity is not fully known, the presence of a central oscillator is generally accepted as being responsible. A high frecuency tremor, between 13 and 18 Hz, constitutes an almost patognomonic finding, and treatment with clonazepam usually improves the symptoms. We present a patient who described his symptoms as "cramps" in lower limbs and trunk on standing up, which were relieved on walking or resting. This clinical presentation together with a neurophysiological recording of the tremor showing an activity of lower frequency (8 Hz) combined with the usual higher frequency (16 Hz) and above all the clear amelioration of symptoms when treated with gabapentin, i.e. resolution of the low frequency tremor without changes in the 16 Hz tremor, were the peculiar features of this case which merits discussion. The slow component of the orthostatic tremor is crucial in this case. The improvement with gabapentin is explained by the disappearance of this slow c

  3. Phenomenology of tremor-like signals observed over hydrocarbon reservoirs

    NARCIS (Netherlands)

    Dangel, S.; Schaepman, M.E.; Stoll, E.P.; Carniel, R.; Barzandji, O.; Rode, E.D.; Singer, J.M.

    2003-01-01

    We have observed narrow-band, low-frequency (1.5-4 Hz, amplitude 0.01-10 mum/s) tremor signals on the surface over hydrocarbon reservoirs (oil, gas and water multiphase fluid systems in porous media) at currently 15 sites worldwide. These 'hydrocarbon tremors' possess remarkably similar spectral and

  4. Estimation of the phase response curve from Parkinsonian tremor.

    Science.gov (United States)

    Saifee, Tabish A; Edwards, Mark J; Kassavetis, Panagiotis; Gilbertson, Tom

    2016-01-01

    Phase response curves (PRCs), characterizing the response of an oscillator to weak external perturbation, have been estimated from a broad range of biological oscillators, including single neurons in vivo. PRC estimates, in turn, provide an intuitive insight into how oscillatory systems become entrained and how they can be desynchronized. Here, we explore the application of PRC theory to the case of Parkinsonian tremor. Initial attempts to establish a causal effect of subthreshold transcranial magnetic stimulation applied to primary motor cortex on the filtered tremor phase were unsuccessful. We explored the possible explanations of this and demonstrate that assumptions made when estimating the PRC in a traditional setting, such as a single neuron, are not arbitrary when applied to the case of tremor PRC estimation. We go on to extract the PRC of Parkinsonian tremor using an iterative method that requires varying the definition of the tremor cycle and estimating the PRC at multiple peristimulus time samples. Justification for this method is supported by estimates of PRC from simulated single neuron data. We provide an approach to estimating confidence limits for tremor PRC and discuss the interpretational caveats introduced by tremor harmonics and the intrinsic variability of the tremor's period. Copyright © 2016 the American Physiological Society.

  5. Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus

    NARCIS (Netherlands)

    Dirkx, M.F.M.; Ouden, H.E.M. den; Aarts, E.; Timmer, M.H.M.; Bloem, B.R.; Toni, I.; Helmich, R.C.G.

    2017-01-01

    Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic

  6. Dopamine reduces Parkinson's tremor through increased thalamic inhibition

    NARCIS (Netherlands)

    Dirkx, M.F.M.; Ouden, H.E.M. den; Aarts, E.; Timmer, M.H.M.; Bloem, B.R.; Toni, I.; Helmich, R.C.G.

    2016-01-01

    Objective: To identify cerebral mechanisms explaining the effects of dopamine on rest tremor in Parkinson's disease. Background: Resting tremor in Parkinson's disease is related to altered activity in the basal ganglia and in the cerebello-thalamo-cortical circuit. Dopaminergic medication reduces

  7. Postural Tremor and Ataxia Progression in Spinocerebellar Ataxias.

    Science.gov (United States)

    Gan, Shi-Rui; Wang, Jie; Figueroa, Karla P; Pulst, Stefan M; Tomishon, Darya; Lee, Danielle; Perlman, Susan; Wilmot, George; Gomez, Christopher M; Schmahmann, Jeremy; Paulson, Henry; Shakkottai, Vikram G; Ying, Sarah H; Zesiewicz, Theresa; Bushara, Khalaf; Geschwind, Michael D; Xia, Guangbin; Subramony, S H; Ashizawa, Tetsuo; Kuo, Sheng-Han

    2017-01-01

    Postural tremor can sometimes occur in spinocerebellar ataxias (SCAs). However, the prevalence and clinical characteristics of postural tremor in SCAs are poorly understood, and whether SCA patients with postural tremor have different ataxia progression is not known. We studied postural tremor in 315 patients with SCA1, 2, 3, and 6 recruited from the Clinical Research Consortium for Spinocerebellar Ataxias (CRC-SCA), which consists of 12 participating centers in the United States, and we evaluated ataxia progression in these patients from January 2010 to August 2012. Among 315 SCA patients, postural tremor was most common in SCA2 patients (SCA1, 5.8%; SCA2, 27.5%; SCA3, 12.4%; SCA6, 16.9%; p = 0.007). SCA3 patients with postural tremor had longer CAG repeat expansions than SCA3 patients without postural tremor (73.67 ± 3.12 vs. 70.42 ± 3.96, p = 0.003). Interestingly, SCA1 and SCA6 patients with postural tremor had a slower rate of ataxia progression (SCA1, β = -0.91, p < 0.001; SCA6, β = -1.28, p = 0.025), while SCA2 patients with postural tremor had a faster rate of ataxia progression (β = 1.54, p = 0.034). We also found that the presence of postural tremor in SCA2 patients could be influenced by repeat expansions of ATXN1 (β = -1.53, p = 0.037) and ATXN3 (β = 0.57, p = 0.018), whereas postural tremor in SCA3 was associated with repeat lengths in TBP (β = 0.63, p = 0.041) and PPP2R2B (β = -0.40, p = 0.032). Postural tremor could be a clinical feature of SCAs, and the presence of postural tremor could be associated with different rates of ataxia progression. Genetic interactions between ataxia genes might influence the brain circuitry and thus affect the clinical presentation of postural tremor.

  8. Vocal Tremor: Novel Therapeutic Target for Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Vinod K. Ravikumar

    2016-10-01

    Full Text Available Tremulous voice is characteristically associated with essential tremor, and is referred to as essential vocal tremor (EVT. Current estimates suggest that up to 40% of individuals diagnosed with essential tremor also present with EVT, which is associated with an impaired quality of life. Traditional EVT treatments have demonstrated limited success in long-term management of symptoms. However, voice tremor has been noted to decrease in patients receiving deep brain stimulation (DBS with the targeting of thalamic nuclei. In this study, we describe our multidisciplinary procedure for awake, frameless DBS with optimal stimulation targets as well as acoustic analysis and laryngoscopic assessment to quantify tremor reduction. Finally, we investigate the most recent clinical evidence regarding the procedure.

  9. Tectonic tremor and LFEs on a reverse fault in Taiwan

    Science.gov (United States)

    Aguiar, Ana C.; Chao, Kevin; Beroza, Gregory C.

    2017-07-01

    We compare low-frequency earthquakes (LFEs) from triggered and ambient tremor under the southern Central Range, Taiwan. We apply the PageRank algorithm used by Aguiar and Beroza (2014) that exploits the repetitive nature of the LFEs to find repeating LFEs in both ambient and triggered tremor. We use these repeaters to create LFE templates and find that the templates created from both tremor types are very similar. To test their similarity, we use both interchangeably and find that most of both the ambient and triggered tremor match the LFE templates created from either data set, suggesting that LFEs for both events have a common origin. We locate the LFEs by using local earthquake P wave and S wave information and find that LFEs from triggered and ambient tremor locate to between 20 and 35 km on what we interpret as the deep extension of the Chaochou-Lishan Fault.

  10. Global search of triggered non-volcanic tremor

    Science.gov (United States)

    Chao, Tzu-Kai Kevin

    Deep non-volcanic tremor is a newly discovered seismic phenomenon with low amplitude, long duration, and no clear P- and S-waves as compared with regular earthquake. Tremor has been observed at many major plate-boundary faults, providing new information about fault slip behaviors below the seismogenic zone. While tremor mostly occurs spontaneously (ambient tremor) or during episodic slow-slip events (SSEs), sometimes tremor can also be triggered during teleseismic waves of distance earthquakes, which is known as "triggered tremor". The primary focus of my Ph.D. work is to understand the physical mechanisms and necessary conditions of triggered tremor by systematic investigations in different tectonic regions. In the first chapter of my dissertation, I conduct a systematic survey of triggered tremor beneath the Central Range (CR) in Taiwan for 45 teleseismic earthquakes from 1998 to 2009 with Mw ≥ 7.5. Triggered tremors are visually identified as bursts of high-frequency (2-8 Hz), non-impulsive, and long-duration seismic energy that are coherent among many seismic stations and modulated by the teleseismic surface waves. A total of 9 teleseismic earthquakes has triggered clear tremor in Taiwan. The peak ground velocity (PGV) of teleseismic surface waves is the most important factor in determining tremor triggering potential, with an apparent threshold of ˜0.1 cm/s, or 7-8 kPa. However, such threshold is partially controlled by the background noise level, preventing triggered tremor with weaker amplitude from being observed. In addition, I find a positive correlation between the PGV and the triggered tremor amplitude, which is consistent with the prediction of the 'clock-advance' model. This suggests that triggered tremor can be considered as a sped-up occurrence of ambient tremor under fast loading from the passing surface waves. Finally, the incident angles of surface waves also play an important rule in controlling the tremor triggering potential. The next

  11. Motor and Non-motor Features: Differences between Patients with Isolated Essential Tremor and Patients with Both Essential Tremor and Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Apostolia Ghika

    2015-08-01

    Full Text Available Background: Patients with essential tremor (ET who develop Parkinson’s disease (ET->PD may differ with respect to motor features (MFs and non-motor features (NMFs from patients with isolated ET. Few studies have assessed this issue. Methods: In this retrospective chart review, we analyzed data on MFs and NMFs of 175 patients, including 54 ET->PD and 121 ET, actively followed in the Athens University 1st Neurology Department. Results: Significantly more ET->PD than ET patients reported asymmetric tremor at ET onset (68.5% vs. 14.9%, p<0.001.  Significantly more ET than ET->PD patients had head tremor (43.5% vs. 13.2%, p<0.001 and cerebellar signs (41.3% vs. 9.3%, p<0.001. More ET than ET->PD patients reported hearing impairment (65.3% vs. 28.3%, p<0.001 and restless legs syndrome (34.8% vs. 3.7%, p<0.001. Conversely, a larger proportion of ET->PD than ET patients reported rapid eye movement behavior disorder (51.9% vs. 10.0%, p<0.001, constipation (67.9% vs. 36.4%, p<0.001, and olfactory dysfunction (83.3% vs. 36.4%, p<0.001. Discussion: The subset of ET->PD patients may have distinct MFs and NMFs that should be assessed further for the possible predictive value for the emergence of PD.  

  12. Management of radiation therapy-induced mucositis in head and neck cancer patients. Part II: supportive treatments

    Directory of Open Access Journals (Sweden)

    Wei Cheong Ngeow

    2011-12-01

    Full Text Available Oropharyngeal mucositis is the acute inflammatory and ulcerative reaction of the oral mucosa following radiation therapy to the head and neck region. It is such a common problem that nearly all head and neck cancer patients develop some degree of mucositis. This complication is usually transient in nature but it also represents an important clinical problem as it is a painful, debilitating, dose-dependent side effect for which there is no widely acceptable prophylaxis or effective treatment. As several authoritative groups have recently either undertaken systematic reviews or issued guidelines on the management of mucositis, it is the aim of this review instead, to provide an overview of all the remedies and pharmaceutical agents available, as well as highlighting to researchers the gaps that need to be filled.

  13. The Connective Tissue Components of Optic Nerve Head Cupping in Monkey Experimental Glaucoma Part 1: Global Change

    Science.gov (United States)

    Yang, Hongli; Ren, Ruojin; Lockwood, Howard; Williams, Galen; Libertiaux, Vincent; Downs, Crawford; Gardiner, Stuart K.; Burgoyne, Claude F.

    2015-01-01

    Purpose To characterize optic nerve head (ONH) connective tissue change within 21 monkey experimental glaucoma (EG) eyes, so as to identify its principal components. Methods Animals were imaged three to five times at baseline then every 2 weeks following chronic unilateral IOP elevation, and euthanized early through end-stage confocal scanning laser tomographic change. Optic nerve heads were serial-sectioned, three-dimensionally (3D) reconstructed, delineated, and quantified. Overall EG versus control eye differences were assessed by general estimating equations (GEE). Significant, animal-specific, EG eye change was required to exceed the maximum physiologic intereye differences in six healthy animals. Results Overall EG eye change was significant (P cupping” in monkey EG which serve as targets for longitudinally staging and phenotyping ONH connective tissue alteration within all forms of monkey and human optic neuropathy. PMID:26641545

  14. Prevalence and characteristics of tremor in the NARCOMS multiple sclerosis registry: a cross-sectional survey.

    Science.gov (United States)

    Rinker, John R; Salter, Amber R; Walker, Harrison; Amara, Amy; Meador, William; Cutter, Gary R

    2015-01-08

    (1)To describe the prevalence and severity of tremor in patients with multiple sclerosis (MS) registered within a large North American MS registry; (2) to provide detailed descriptions on the characteristics and severity of tremor in a subset of registrants and (3) to compare several measures of tremor severity for strength of agreement. The North American Research Committee on MS (NARCOMS) registry. Registrants of NARCOMS reporting mild or greater tremor severity. We determined the cross-sectional prevalence of tremor in the NARCOMS registry over three semiannual updates between fall 2010 and fall 2011. A subset of registrants (n=552) completed a supplemental survey providing detailed descriptions of their tremor. Outcomes included descriptive characteristics of their tremors and correlations between outcome measures to determine the strength of agreement in assessing tremor severity. The estimated prevalence of tremor in NARCOMS ranged from 45% to 46.8%, with severe tremor affecting 5.5-5.9% of respondents. In the subset completing the supplemental survey, mild tremor severity was associated with younger age of MS diagnosis and tremor onset than those with moderate or severe tremor. However, tremor severity did not differ by duration of disease or tremor. Respondents provided descriptions of tremor symptoms on the Clinical Ataxia Rating Scale, which had a moderate to good (ρ=0.595) correlation with the Tremor Related Activities of Daily Living (TRADL) scale. Objectively scored Archimedes' spirals had a weaker (ρ=0.358) correlation with the TRADL. Rates of unemployment, disability and symptomatic medication use increased with tremor severity, but were high even among those with mild tremor. Tremor is common among NARCOMS registrants and severely disabling for some. Both ADL-based and symptom-descriptive measures of tremor severity can be used to stratify patients. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted

  15. Quantitative methods for evaluating the efficacy of thalamic deep brain stimulation in patients with essential tremor.

    Science.gov (United States)

    Wastensson, Gunilla; Holmberg, Björn; Johnels, Bo; Barregard, Lars

    2013-01-01

    Deep brain stimulation (DBS) of the thalamus is a safe and efficient method for treatment of disabling tremor in patient with essential tremor (ET). However, successful tremor suppression after surgery requires careful selection of stimulus parameters. Our aim was to examine the possible use of certain quantitative methods for evaluating the efficacy of thalamic DBS in ET patients in clinical practice, and to compare these methods with traditional clinical tests. We examined 22 patients using the Essential Tremor Rating Scale (ETRS) and quantitative assessment of tremor with the stimulator both activated and deactivated. We used an accelerometer (CATSYS tremor Pen) for quantitative measurement of postural tremor, and a eurythmokinesimeter (EKM) to evaluate kinetic tremor in a rapid pointing task. The efficacy of DBS on tremor suppression was prominent irrespective of the method used. The agreement between clinical rating of postural tremor and tremor intensity as measured by the CATSYS tremor pen was relatively high (rs = 0.74). The agreement between kinetic tremor as assessed by the ETRS and the main outcome variable from the EKM test was low (rs = 0.34). The lack of agreement indicates that the EKM test is not comparable with the clinical test. Quantitative methods, such as the CATSYS tremor pen, could be a useful complement to clinical tremor assessment in evaluating the efficacy of DBS in clinical practice. Future studies should evaluate the precision of these methods and long-term impact on tremor suppression, activities of daily living (ADL) function and quality of life.

  16. The distributed somatotopy of tremor: a window into the motor system

    NARCIS (Netherlands)

    Helmich, R.C.G.

    2013-01-01

    The posterior ventrolateral thalamus (VLp) plays a crucial role in Parkinson's tremor and in essential tremor: deep brain stimulation (DBS) of the VLp effectively diminishes both tremor types. Previous research has shown tremor oscillations in the VLp, but the spatial extent and somatotopy of these

  17. Rest and action tremor in Parkinson's disease: effects of Deep Brain Stimulation

    NARCIS (Netherlands)

    Heida, Tjitske; Wentink, E.C.

    2010-01-01

    One of the cardinal symptoms of Parkinson’s disease is rest tremor. While rest tremor generally disappears during sleep and voluntary movement, action tremor may be triggered by voluntary movement, and may even be more disabling than rest tremor. Deep brain stimulation (DBS) in the subthalamic

  18. Single-plane compensatory phase shift of head and eye oscillations in infantile nystagmus syndrome.

    Science.gov (United States)

    Anagnostou, Evangelos; Spengos, Konstantinos; Anastasopoulos, Dimitri

    2011-09-15

    A 43-year-old man with infantile nystagmus syndrome complained of "head tremor" that would occur during attempted reading. Three-dimensional, combined eye and head recordings were performed with the magnetic search coil technique in two conditions: 1) looking straight-ahead under photopic conditions without a particular attentional focus and 2) reading a simple text held one meter away. A mainly vertical-horizontal spontaneous nystagmus was evident in both conditions, whereas head nodding emerged in the second condition. The head oscillated only in the vertical plane and concomitant analysis of eye and head displacement revealed a counterphase, compensatory pattern of the first harmonic of the INS waveform. This was verified by the significant negative peak of the crosscorrelogram at zero lag. Eye-in-space (gaze) displacement during nystagmic oscillations was thereby reduced suggesting a central adaptive behavior that may have evolved to partly compensate for the abnormal eye movements during reading. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Effects of beta-blockers and nicardipine on oxotremorine-induced tremor in common marmosets.

    Science.gov (United States)

    Mitsuda, M; Nomoto, M; Iwata, S

    1999-10-01

    Effects of beta-blockers (propranolol, arotinolol and nipradilol) and a Ca2+ channel blocker (nicardipine) on oxotremorine-induced tremor were studied in common marmosets. Generalized tremor was elicited by an intraperitoneal administration of 0.25 mg/kg oxotremorine. Intensity of the tremor was classified into 7 degrees, and it was evaluated every 10 min. The total intensity of oxotremorine-induced tremor for each drug was expressed as "points", which were the sum of tremor intensity scores evaluated every 10 min up to 190 min following the administration of oxotremorine. Beta-blockers significantly suppressed the tremor. On the other hand, the Ca2+ channel blocker exacerbated the tremor.

  20. Real-Time Estimation of Pathological Tremor Parameters from Gyroscope Data

    Directory of Open Access Journals (Sweden)

    José L. Pons

    2010-03-01

    Full Text Available This paper presents a two stage algorithm for real-time estimation of instantaneous tremor parameters from gyroscope recordings. Gyroscopes possess the advantage of providing directly joint rotational speed, overcoming the limitations of traditional tremor recording based on accelerometers. The proposed algorithm first extracts tremor patterns from raw angular data, and afterwards estimates its instantaneous amplitude and frequency. Real-time separation of voluntary and tremorous motion relies on their different frequency contents, whereas tremor modelling is based on an adaptive LMS algorithm and a Kalman filter. Tremor parameters will be employed to drive a neuroprosthesis for tremor suppression based on biomechanical loading.

  1. Real-Time Estimation of Pathological Tremor Parameters from Gyroscope Data

    Science.gov (United States)

    Gallego, Juan A.; Rocon, Eduardo; Roa, Javier O.; Moreno, Juan C.; Pons, José L.

    2010-01-01

    This paper presents a two stage algorithm for real-time estimation of instantaneous tremor parameters from gyroscope recordings. Gyroscopes possess the advantage of providing directly joint rotational speed, overcoming the limitations of traditional tremor recording based on accelerometers. The proposed algorithm first extracts tremor patterns from raw angular data, and afterwards estimates its instantaneous amplitude and frequency. Real-time separation of voluntary and tremorous motion relies on their different frequency contents, whereas tremor modelling is based on an adaptive LMS algorithm and a Kalman filter. Tremor parameters will be employed to drive a neuroprosthesis for tremor suppression based on biomechanical loading. PMID:22294919

  2. Improvement of Primary Writing Tremor in Parkinson's Disease with Carbidopa/Levodopa.

    Science.gov (United States)

    Battista, James P; Greene, Paul E

    2015-01-01

    Primary writing tremor is a task-specific phenomenon that has been described as variants of essential tremor or dystonia. We describe the case of a 63-year-old female who initially had primary writing tremor, later developed Parkinson's disease, and once initiated on carbidopa/levodopa had improvement in her parkinsonism and her writing tremor. As neither essential tremor nor typical brachial dystonia respond to carbidopa/levodopa, our case documents that at least some cases of primary writing tremor are not variants of either dystonia or essential tremor.

  3. Linkage of familial essential tremor to chromosome 5q35.

    Science.gov (United States)

    Hicks, James E; Konidari, Ioanna; Scott, Burton L; Stajich, Jeffrey M; Ashley-Koch, Allison E; Gilbert, John R; Scott, William K

    2016-07-01

    Essential tremor is a neurological condition characterized by tremor during voluntary movement. To date, 3 loci linked to familial essential tremor have been identified. We examined 48 essential tremor patients in 5 large essential tremor pedigrees in our data set for genetic linkage using an Affymetrix Axiom array. Linkage analysis was performed using an affecteds-only dominant model in SIMWALK2. To incorporate all genotype information, GERMLINE was used to identify genome segments shared identical-by-descent in pairs of affecteds. Exome sequencing was performed in pedigrees showing evidence of linkage. For one family, chromosomes 5 and 18 showed genome-wide significant linkage to essential tremor. Shared segment analysis excluded the 18p11 candidate region and reduced the 5q35 region by 1 megabase. Exome sequencing did not identify a potential causative variant in this region. A locus on chromosome 5 is linked to essential tremor. Further research is needed to identify a causative variant. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  4. [Essential tremor and Parkinson's disease: are they associated?].

    Science.gov (United States)

    Labiano-Fontcuberta, Andrés; Benito-León, Julián

    2012-10-16

    There is now growing evidence that essential tremor and Parkinson's disease are related. To present the main findings from epidemiologic, genetic, clinical, imaging and pathologic studies, contrasting evidences for and against an association between essential tremor and Parkinson's disease. We include a complete update of the latest findings regarding the overlap between these two disorders. There is current evidence that a history of essential tremor may herald the onset of Parkinson's disease in a subset of patients. Furthermore, the fact that the risk of essential tremor is significantly increased in relatives of patients with Parkinson's disease suggests the possibility that both conditions are genetically related, probably sharing common hereditary predisposition. Dopaminergic deficit among essential tremor patients in functional imaging studies and recent pathological studies describing Lewy bodies in some essential tremor patients, support further evidence for an overlap between both conditions, at least in a subset of patients. The convergence of all the reviewed data suggests the possible existence of a mixed essential tremor-Parkinson's disease phenotype in some patients. However, further studies are needed to better understand this phenotype.

  5. Oral toxicity management in head and neck cancer patients treated with chemotherapy and radiation: Xerostomia and trismus (Part 2). Literature review and consensus statement.

    Science.gov (United States)

    Buglione, Michela; Cavagnini, Roberta; Di Rosario, Federico; Maddalo, Marta; Vassalli, Lucia; Grisanti, Salvatore; Salgarello, Stefano; Orlandi, Ester; Bossi, Paolo; Majorana, Alessandra; Gastaldi, Giorgio; Berruti, Alfredo; Trippa, Fabio; Nicolai, Pietro; Barasch, Andrei; Russi, Elvio G; Raber-Durlacher, Judith; Murphy, Barbara; Magrini, Stefano M

    2016-06-01

    Radiotherapy alone or in combination with chemotherapy and/or surgery is a well-known radical treatment for head and neck cancer patients. Nevertheless acute side effects (such as moist desquamation, skin erythema, loss of taste, mucositis etc.) and in particular late toxicities (osteoradionecrosis, xerostomia, trismus, radiation caries etc.) are often debilitating and underestimated. A multidisciplinary group of head and neck cancer specialists from Italy met in Milan with the aim of reaching a consensus on a clinical definition and management of these toxicities. The Delphi Appropriateness method was used for this consensus and external experts evaluated the conclusions. The paper contains 20 clusters of statements about the clinical definition and management of stomatological issues that reached consensus, and offers a review of the literature about these topics. The review was split into two parts: the first part dealt with dental pathologies and osteo-radionecrosis (10 clusters of statements), whereas this second part deals with trismus and xerostomia (10 clusters of statements). Copyright © 2016. Published by Elsevier Ireland Ltd.

  6. Suppression of enhanced physiological tremor via stochastic noise: initial observations.

    Directory of Open Access Journals (Sweden)

    Carlos Trenado

    Full Text Available Enhanced physiological tremor is a disabling condition that arises because of unstable interactions between central tremor generators and the biomechanics of the spinal stretch reflex. Previous work has shown that peripheral input may push the tremor-related spinal and cortical systems closer to anti-phase firing, potentially leading to a reduction in tremor through phase cancellation. The aim of the present study was to investigate whether peripherally applied mechanical stochastic noise can attenuate enhanced physiological tremor and improve motor performance. Eight subjects with enhanced physiological tremor performed a visuomotor task requiring the right index finger to compensate a static force generated by a manipulandum to which Gaussian noise (3-35 Hz was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a larger green circle. Electromyogram (EMG from the active hand muscles and finger position were recorded. Performance was measured by the mean absolute deviation of the white dot from the zero position. Tremor was identified by the acceleration in the frequency range 7-12 Hz. Two different conditions were compared: with and without superimposed noise at optimal amplitude (determined at the beginning of the experiment. The application of optimum noise reduced tremor (accelerometric amplitude and EMG activity and improved the motor performance (reduced mean absolute deviation from zero. These data provide the first evidence of a significant reduction of enhanced physiological tremor in the human sensorimotor system due to application of external stochastic noise.

  7. Serotonergic modulation of nicotine-induced kinetic tremor in mice.

    Science.gov (United States)

    Kunisawa, Naofumi; Iha, Higor A; Nomura, Yuji; Onishi, Misaki; Matsubara, Nami; Shimizu, Saki; Ohno, Yukihiro

    2017-06-01

    We previously demonstrated that nicotine elicited kinetic tremor by elevating the neural activity of the inferior olive via α7 nicotinic acetylcholine (nACh) receptors. Since α7 nACh receptors reportedly facilitate synaptic monoamine release, we explored the role of 5-HT receptors in induction and/or modulation of nicotine tremor. Treatment of mice with nicotine induced kinetic tremor that normally appeared during movement. The 5-HT 1A agonist, 8-hydroxydipropylaminotetraline (8-OH-DPAT), significantly enhanced nicotine-induced tremor and the action of 8-OH-DPAT was antagonized by WAY-100135 (5-HT 1A antagonist). In addition, the cerebral 5-HT depletion by repeated treatment with p-chlorophenylalanine did not reduce, but rather potentiated the facilitatory effects of 8-OH-DPAT. In contrast, the 5-HT 2 agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), significantly attenuated nicotine tremor, which was antagonized by ritanserin (5-HT 2 antagonist). The 5-HT 3 agonist SR-57227 did not affect nicotine-induced tremor. Furthermore, when testing the direct actions of 5-HT antagonists, nicotine tremor was inhibited by WAY-100135, but was unaffected by ritanserin, ondansetron (5-HT 3 antagonist) or SB-258585 (5-HT 6 antagonist). These results suggest that postsynaptic 5-HT 1A receptors are involved in induction of nicotine tremor mediated by α7 nACh receptors. In addition, 5-HT 2 receptors have an inhibitory modulatory role in induction of nicotine tremor. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  8. Suppression of enhanced physiological tremor via stochastic noise: initial observations.

    Science.gov (United States)

    Trenado, Carlos; Amtage, Florian; Huethe, Frank; Schulte-Mönting, Jürgen; Mendez-Balbuena, Ignacio; Baker, Stuart N; Baker, Mark; Hepp-Reymond, Marie-Claude; Manjarrez, Elias; Kristeva, Rumyana

    2014-01-01

    Enhanced physiological tremor is a disabling condition that arises because of unstable interactions between central tremor generators and the biomechanics of the spinal stretch reflex. Previous work has shown that peripheral input may push the tremor-related spinal and cortical systems closer to anti-phase firing, potentially leading to a reduction in tremor through phase cancellation. The aim of the present study was to investigate whether peripherally applied mechanical stochastic noise can attenuate enhanced physiological tremor and improve motor performance. Eight subjects with enhanced physiological tremor performed a visuomotor task requiring the right index finger to compensate a static force generated by a manipulandum to which Gaussian noise (3-35 Hz) was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a larger green circle. Electromyogram (EMG) from the active hand muscles and finger position were recorded. Performance was measured by the mean absolute deviation of the white dot from the zero position. Tremor was identified by the acceleration in the frequency range 7-12 Hz. Two different conditions were compared: with and without superimposed noise at optimal amplitude (determined at the beginning of the experiment). The application of optimum noise reduced tremor (accelerometric amplitude and EMG activity) and improved the motor performance (reduced mean absolute deviation from zero). These data provide the first evidence of a significant reduction of enhanced physiological tremor in the human sensorimotor system due to application of external stochastic noise.

  9. Quantitative Assessment of Parkinsonian Tremor Based on an Inertial Measurement Unit

    OpenAIRE

    Houde Dai; Pengyue Zhang; Lueth, Tim C

    2015-01-01

    Quantitative assessment of parkinsonian tremor based on inertial sensors can provide reliable feedback on the effect of medication. In this regard, the features of parkinsonian tremor and its unique properties such as motor fluctuations and dyskinesia are taken into account. Least-square-estimation models are used to assess the severities of rest, postural, and action tremors. In addition, a time-frequency signal analysis algorithm for tremor state detection was also included in the tremor as...

  10. Research progress in non-motor symptoms of essential tremor

    Directory of Open Access Journals (Sweden)

    Xi WANG

    2014-05-01

    Full Text Available Essential tremor (ET, a movement disorder characterized by postural or kinetic tremor as the main clinical manifestations, is one of the most common neurological diseases. Traditional view contends that essential tremor is a benign movement disorder with merely motor symptoms. Recent researches show that patients may have some non-motor symptoms besides motor symptoms. Researches and exploration on its non-motor symptoms provide us with a new perspective for clinical diagnosis, treatment and better understanding of the disease. doi: 10.3969/j.issn.1672-6731.2014.05.016

  11. Familial orthostatic tremor and essential tremor in two young brothers: A rare entity

    Directory of Open Access Journals (Sweden)

    Kalyan B Bhattacharyya

    2013-01-01

    Full Text Available Orthostatic tremor (OT, is usually a disease of old age and is characterized by quivering movements of the legs during quiet standing or in the state of isometric contraction in the lower limbs. This is relieved on walking or on lying down. It is diagnosed by surface electromyography, particularly over the quadriceps femoris muscles which shows a distinctive frequency of 13 to 18 Hz on standing. Some investigators consider it as a variant of essential tremor (ET and the two conditions often co-exist. The disease is usually non-familial. Two brothers presented with tremor in the lower limbs on standing and on the outstretched hands without any family history. Subsequently, they were proved to be suffering from OT and ET by clinical examination and surface EMG. Simultaneous occurrence of OT and ET in two young brothers without any family history in the previous generation has not been described before and they also appeared at a much earlier age than what is described in the literature.

  12. Familial Cortical Myoclonic Tremor with Epilepsy and Cerebellar Changes: Description of a New Pathology Case and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Sarvi Sharifi

    2012-08-01

    Full Text Available Background: Over 60 Asian and European families with cortical myoclonic tremor and epilepsy have been reported under various names. Cerebellar changes may be part of the syndrome. In this study, we report the neuropathology findings in a new Dutch familial cortical myoclonic tremor with epilepsy case and review the literature on this syndrome.Methods: Neuropathological investigations were performed for a third case of the Dutch pedigree. In addition, we searched the literature for pedigrees meeting the criteria for benign familial myoclonic tremor and epilepsy.Results: Our third Dutch case showed cerebellar Purkinje cell changes and a normal cerebral cortex. The pedigrees described show phenotypical differences, cerebellar symptoms and cerebellar atrophy to a variable degree. Japanese pedigrees with linkage to chromosome 8q have been reported with milder disease features than members of Italian pedigrees with linkage to chromosome 2p. French pedigrees (5p possibly show even more severe and progressive disease, including cognitive changes and cerebellar features.Discussion: Currently, familial cortical myoclonic tremor is not listed by the International League Against Epilepsy, although it can be differentiated from other epileptic syndromes. Genetic heterogeneity and phenotypical differences between pedigrees exist. Cerebellar changes seem to be part of the syndrome in at least a number of pedigrees.

  13. Medication non-adherence in essential tremor.

    Science.gov (United States)

    Louis, Elan D

    2015-02-01

    There are numerous studies of medication adherence in a variety of chronic diseases including Parkinson's disease; however, there are no such studies in patients with essential tremor (ET). This study aimed to (1) present self-report data on medication adherence in ET cases, (2) examine the demographic and clinical factors that might be associated with lower medication adherence. 151 ET cases were enrolled in a clinical-epidemiological study at Columbia University. An 11-item medication adherence questionnaire, modeled after the Morisky medication adherence questionnaire, was administered. Seventy-three (48.3%) of 151 cases were taking daily medication for ET. One-third (24/73; 32.9%) of cases reported that they sometimes forgot to take their medication, and 1 in 5 (15/73; 20.5%) reported missed doses within the past week. Most striking was that nearly 1 in 4 (17/73; 23.3%) reported that there were whole days in the past two weeks in which they had not taken their medication. A factor analysis revealed four factors that captured different aspects of non-adherence. Higher non-adherence was associated with more depressive symptoms, younger age, and less severe tremor but was not associated with type or number of ET medications. Approximately one in four ET patients reported whole days in the past two weeks in which they had not taken their medication. It is possible that this relatively high rate of non-adherence could be a function of the poor therapeutic efficacy of the medications currently available to treat ET. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Long-term tremor therapy for Parkinson and essential tremor with sensor-guided botulinum toxin type A injections

    Science.gov (United States)

    Samotus, Olivia; Lee, Jack; Jog, Mandar

    2017-01-01

    Objective Current pharmacological agents used to treat Parkinson disease (PD) tremor and essential tremor (ET) provide suboptimal benefit and are commonly associated with significant adverse effects. Botulinum toxin type A (BoNT-A) has been shown to be effective for wrist tremor though functionally bothersome muscle weakness frequently occurs. This is the longest study to date demonstrating that BoNT-A therapy coupled with kinematic guidance can provide efficacious outcomes for upper limb tremor with minimized unwanted weakness. Methods A total of 28 PD and 24 ET participants with bothersome, disabling tremor, received six serial BoNT-A treatments every 16 weeks starting at week 0 with a follow-up visit 6 weeks following a treatment, totaling 96 weeks. Clinical scales, including Fahn-Tolosa-Marin tremor rating scale (FTM), and sensor-based tremor assessments were conducted at each visit. Kinematics was utilized to identify which arm muscles contributed to the tremulous movements and the experienced injector used clinical expertise in determining BoNT-A dosages. Results Following BoNT-A treatment, clinical ratings of tremor severity and functional ability (FTM) showed significant improvements following the first treatment which was maintained up to week 96 in PD and ET. Kinematics detected a significant reduction in PD and ET tremor amplitudes by 70% and 76% over the treatment course, respectively. By objectively distinguishing tremulous muscles and tremor severity, adverse effects were limited to mild perceived weakness by participants in injected muscles during follow-ups. Following the fourth treatment, BoNT-A dosages in flexor and extensor wrist muscles and biceps were reduced for those experiencing residual weakness which ultimately did not interfere with tremor relief or arm function. Conclusions Kinematics is an objective method that can aid clinicians in assessing and determining optimal BoNT-A parameters to alleviate both PD and ET tremor. BoNT-A injections

  15. Botulinum Toxin Type A Injections as Monotherapy for Upper Limb Essential Tremor Using Kinematics.

    Science.gov (United States)

    Samotus, Olivia; Kumar, Niraj; Rizek, Philippe; Jog, Mandar

    2018-01-01

    There is a significant need for a targeted therapy for essential tremor (ET), as medications have not been developed specifically for ET, and the ones prescribed are often not well-tolerated, so that many patients remain untreated. Recent work has shown that, unlike previous experience, kinematically guided individualized botulinum toxin type A (BoNT-A) injections provide benefit along with minimal weakness. Ours is the first long-term (96-week) safety and efficacy study of BoNT-A as monotherapy for ET using kinematically driven injection parameters. Ten ET patients were administered six serial BoNT-A treatments every 16 weeks and were assessed at 6 weeks following treatment. During each study visit, the Fahn-Tolosa-Marin (FTM) scale, the Unified Parkinson's Disease Rating Scale, and the Quality of Life for Essential Tremor Questionnaire (QUEST) were administered along with kinematic assessment of the treated limb. Participants performed scripted tasks with motion sensors placed over each arm joint. Dosing patterns were determined using the movement disorder neurologist's interpretation of muscles contributing to the kinematically analyzed upper limb tremor biomechanics. There was a 33.8% (pfunctional improvement (FTM part C) and a 39.8% (ptremor score was reduced by 62.9% (p=0.001) in the treated and by 44.4% (p=0.03) in the untreated arm at week 96 compared to week 48. Individualized BoNT-A dosing patterns to each individual's tremor biomechanics provided an effective monotherapy for ET as function improved without functionally limiting muscle weakness.

  16. Iceberg Harmonic Tremor, Seismometer Data, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Seismometers were placed on a 25 km by 50 km iceberg called C16 in the Ross Sea, Antarctica, to identify the Iceberg harmonic Tremor (IHT) source mechanism and to...

  17. Evaluation of a screening instrument for essential tremor

    DEFF Research Database (Denmark)

    Lorenz, Delia; Papengut, Frank; Frederiksen, Henrik

    2008-01-01

    To evaluate a screening instrument for essential tremor (ET) consisting of a seven-item questionnaire and a spiral drawing. A total of 2,448 Danish twins aged 70 years or more and a second sample aged 60 years or more (n = 1,684) from a population-based northern German cross-sectional study (Pop....... Definite or probable ET was diagnosed in 104 patients, possible in 86 and other tremors in 98 patients. The sensitivity of the screening instrument was 70.5%, the positive predictive value was 64.9%, the specificity was 68.2%, and the negative predictive value was 73.5%. Tremor severity correlated...... significantly with higher spiral scores and more positive items. More patients were identified by spiral drawing in all tremor groups. The interrater and intrarater reliability for spirals ranged from 0.7 to 0.8 using intraclass coefficient. A cluster analysis revealed that the questionnaire can be reduced...

  18. Palatal tremor after lithium and carbamazepine use: a case report

    Directory of Open Access Journals (Sweden)

    Kuruvilla Anju

    2010-06-01

    Full Text Available Abstract Introduction Palatal tremor, characterized by rhythmic contractions of the soft palate, can occur secondary to pathology in the dentato-rubro-olivary pathway, or in the absence of such structural lesions. Its pathogenesis is only partially understood. We describe a case of probable drug-induced palatal tremor. Case presentation A 27-year-old Indian man had taken carbamazepine and lithium for 7 years for the treatment of a manic episode. He presented with a one-year history of bilateral rhythmic oscillations of his soft palate and tremors of his tongue. There were no other abnormalities detected from his examination or after detailed investigation. Conclusion Palatal tremors may result from medication used in the treatment of psychiatric disorders.

  19. Rare association of central pontine myelinolysis with infantile tremor syndrome

    Directory of Open Access Journals (Sweden)

    Kalpana Datta

    2012-01-01

    Full Text Available Central pontine myelinolysis (CPM is an acute demyelination within the central basis pontis. Though exact mechanism is not known it is seen commonly with rapid correction of hyponatremia and also with pontine ischemia or infarction, demyelinating diseases, pontine neoplasm and different metabolic diseases. We report a rare association of CPM in a patient of Infantile Tremor Syndrom (ITS. ITS is a syndrome of tremor, mental and physical retardation, pigmentary changes of hair and skin and anemia in malnourished children. Though first reported in Indian subcontinent many identical cases were reported from around the world. Our case is a 15 month old child with generalized tremor, mild hepatosplenomegaly with features of grade II malnutrition including skin and hair changes. All the signs and symtoms of tremor improved after treatment with the World Health Organization (WHO protocol for protein energy malnutrition (PEM and administration of propranolol without any side effects.

  20. Rare association of central pontine myelinolysis with infantile tremor syndrome.

    Science.gov (United States)

    Datta, Kalpana; Datta, Supratim; Dutta, Indranil

    2012-01-01

    Central pontine myelinolysis (CPM) is an acute demyelination within the central basis pontis. Though exact mechanism is not known it is seen commonly with rapid correction of hyponatremia and also with pontine ischemia or infarction, demyelinating diseases, pontine neoplasm and different metabolic diseases. We report a rare association of CPM in a patient of Infantile Tremor Syndrom (ITS). ITS is a syndrome of tremor, mental and physical retardation, pigmentary changes of hair and skin and anemia in malnourished children. Though first reported in Indian subcontinent many identical cases were reported from around the world. Our case is a 15 month old child with generalized tremor, mild hepatosplenomegaly with features of grade II malnutrition including skin and hair changes. All the signs and symtoms of tremor improved after treatment with the World Health Organization (WHO) protocol for protein energy malnutrition (PEM) and administration of propranolol without any side effects.

  1. Epidemiology and treatment of 23 musicians with task specific tremor.

    Science.gov (United States)

    Lee, André; Furuya, Shinichi; Altenmüller, Eckart

    2014-01-01

    Task specific tremors in musicians have been mainly described as primary bowing tremor in string instrumentalists in relatively small sample sizes. Our aim was to describe epidemiology, risk factors, phenomenology and treatment options of this disorder in 23 musicians of different instruments. We included 23 professional musicians (4 female, 19 male; mean age 51.5 ± 11.4 years) with a TSTM. During anamnesis, clinical examination, by mail or via telephone patients were asked for epidemiological, phenomenological information, risk factors and treatments. We then compared our findings to primary writing tremor, the most common task specific tremor. Age at onset of the TST was 44.6 ± 13.6 years and tremor appeared 35.1 ± 13.5 years after beginning to play the instrument. The majority of patients were string instrumentalists, followed by woodwind instrumentalists. Other instrumentalists were a guitarist, pianist and percussionist respectively. In contrast to primary writing tremor, we also found proximal muscles of the upper extremity involved in tremor. A positive family history was found in Prior trauma was more common than in primary writing tremor. Treatment with a positive effect on tremor were in order of efficacy: Botulinumtoxin, Primidone, Propranolol, Trihexyphenidyl. No patient had undergone deep brain stimulation. Task specific tremor in musicians is a heterogeneous disorder with a male gender predominance that shares many commonalities with PWT. The onset age as well as the time between starting to play the instrument and tremor onset has a wide range. Because previous trauma and overuse appear to be risk factors, preventive measures against playing related injuries are necessary. There appears to be a genetic predisposition for TST. No single beneficial medication exists and treatment of patients remains highly individual. It should be discussed, whether deep brain stimulation should be offered not only to patients that do not respond to

  2. Surface-wave potential for triggering tectonic (nonvolcanic) tremor

    Science.gov (United States)

    Hill, D.P.

    2010-01-01

    Source processes commonly posed to explain instances of remote dynamic triggering of tectonic (nonvolcanic) tremor by surface waves include frictional failure and various modes of fluid activation. The relative potential for Love- and Rayleigh-wave dynamic stresses to trigger tectonic tremor through failure on critically stressed thrust and vertical strike-slip faults under the Coulomb-Griffith failure criteria as a function of incidence angle is anticorrelated over the 15- to 30-km-depth range that hosts tectonic tremor. Love-wave potential is high for strike-parallel incidence on low-angle reverse faults and null for strike-normal incidence; the opposite holds for Rayleigh waves. Love-wave potential is high for both strike-parallel and strike-normal incidence on vertical, strike-slip faults and minimal for ~45?? incidence angles. The opposite holds for Rayleigh waves. This pattern is consistent with documented instances of tremor triggered by Love waves incident on the Cascadia mega-thrust and the San Andreas fault (SAF) in central California resulting from shear failure on weak faults (apparent friction, ????? 0.2). However, documented instances of tremor triggered by surface waves with strike-parallel incidence along the Nankai megathrust beneath Shikoku, Japan, is associated primarily with Rayleigh waves. This is consistent with the tremor bursts resulting from mixed-mode failure (crack opening and shear failure) facilitated by near-lithostatic ambient pore pressure, low differential stress, with a moderate friction coefficient (?? ~ 0.6) on the Nankai subduction interface. Rayleigh-wave dilatational stress is relatively weak at tectonic tremor source depths and seems unlikely to contribute significantly to the triggering process, except perhaps for an indirect role on the SAF in sustaining tremor into the Rayleigh-wave coda that was initially triggered by Love waves.

  3. Brain biochemistry in autopsied patients with essential tremor.

    Science.gov (United States)

    Shill, Holly A; Adler, Charles H; Beach, Thomas G; Lue, Lih-Fen; Caviness, John N; Sabbagh, Marwan N; Sue, Lucia I; Walker, Douglas G

    2012-01-01

    The pathology of essential tremor is increasingly being studied; however, there are limited studies of biochemical changes in this condition. We studied several candidate biochemical/anatomical systems in the brain stem, striatum, and cerebellum of 23 essential tremor subjects who came to autopsy, comparing them with a control population. Striatal tyrosine hydroxylase, a marker of dopaminergic neurons, was 91.7 ± 113.2 versus 96.4 ± 102.7 ng/mg (not significant) in cases and controls, respectively. Locus coeruleus dopamine beta-hydroxylase, a marker of noradrenergic neurons, was not significantly different between the essential tremor and control groups. Parvalbumin, a marker of GABAergic neurons, was 199.3 ± 42.0 versus 251.4 ± 74.8 ng/mg (P = .025) in the pons in the region of the locus coeruleus of essential tremor subjects versus controls, whereas there was no difference in cerebellar parvalbumin. These results are supportive of a possible role for reduced GABAergic function in the locus coeruleus in essential tremor. The hypothesis that essential tremor represents early Parkinson's disease was not supported, as striatal dopaminergic markers were not reduced compared with control subjects. Copyright © 2011 Movement Disorder Society.

  4. Maximal force and tremor changes across the menstrual cycle.

    Science.gov (United States)

    Tenan, Matthew S; Hackney, Anthony C; Griffin, Lisa

    2016-01-01

    Sex hormones have profound effects on the nervous system in vitro and in vivo. The present study examines the effect of the menstrual cycle on maximal isometric force (MVC) and tremor during an endurance task. Nine eumenorrheic females participated in five study visits across their menstrual cycle. In each menstrual phase, an MVC and an endurance task to failure were performed. Tremor across the endurance task was quantified as the coefficient of variation in force and was assessed in absolute time and relative percent time to task failure. MVC decreases 23% from ovulation to the mid luteal phase of the menstrual cycle. In absolute time, the mid luteal phase has the highest initial tremor, though the early follicular phase has substantially higher tremor than other phases after 150 s of task performance. In relative time, the mid luteal phase has the highest level of tremor throughout the endurance task. Both MVC and tremor during an endurance task are modified by the menstrual cycle. Performance of tasks and sports which require high force and steadiness to exhaustion may be decreased in the mid luteal phase compared to other menstrual phases.

  5. Jaw tremor as a physiological biomarker of bruxism.

    Science.gov (United States)

    Laine, C M; Yavuz, Ş U; D'Amico, J M; Gorassini, M A; Türker, K S; Farina, D

    2015-09-01

    To determine if sleep bruxism is associated with abnormal physiological tremor of the jaw during a visually-guided bite force control task. Healthy participants and patients with sleep bruxism were given visual feedback of their bite force and asked to trace triangular target trajectories (duration=20s, peak force tremor at ∼8 Hz relative to controls, along with increased masseter EMG activity and force-to-EMG coherence in the same frequency range. Patients also showed lower force-to-EMG coherence at low frequencies (tremor during periods of descending vs. ascending force, while controls showed no difference in tremor with respect to force dynamics. Patients with bruxism have abnormal jaw tremor when engaged in a visually-guided bite force task. Measurement of jaw tremor may aid in the detection/evaluation of bruxism. In light of previous literature, our results also suggest that bruxism is marked by abnormal or mishandled peripheral feedback from the teeth. Copyright © 2015. Published by Elsevier Ireland Ltd.

  6. Essential tremor-Parkinson's disease: A double whammy.

    Science.gov (United States)

    Louis, Elan D; Wise, Adina; Alcalay, Roy N; Rao, Ashwini K; Factor-Litvak, Pam

    2016-07-15

    Surprisingly little has been written about the combined clinical entity, essential tremor-Parkinson's disease (ET-PD), which is the result of a double disease hit. We carefully quantified tremor burden using a wide range of measures (tremor severity, tremor-related disability, tremor-related quality of life) and furthermore, studied additional motor and non-motor features in ET-PD. In this prospective, clinical-epidemiological study, we performed a standardized, structured clinical evaluation of 27 ET-PD patients, comparing them to age-matched samples of 35 PD and 109 ET patients. The number of hours/day shaking was lowest in PD (median=3.0), intermediate in ET (median=10.0) and highest in ET-PD (median=14.0) (ptremor. Aside from a significantly greater tremor burden, ET-PD patients exhibited more cognitive and sleep problems and more mobility and balance problems than patients with isolated PD. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Non-volcanic tremor and discontinuous slab dehydration

    Science.gov (United States)

    Fagereng, Åke; Diener, Johann F. A.

    2011-08-01

    Non-volcanic tremor is a recently discovered fault slip style occurring with remarkable regularity in space near the down-dip end of the locked zone on several subduction thrust interfaces. The physical mechanisms and the controls on the location of tremor have not yet been determined. We calculate the stable mineral assemblages and their water content in the subducting slab, and find that slab dehydration is not continuous, but rather restricted to a few reactions localised in pressure-temperature space. Along geothermal gradients applicable to Shikoku and Cascadia - where tremor has been relatively easy to detect - tremor locations correlate with discontinuous and localised voluminous water release from the breakdown of lawsonite and chlorite + glaucophane respectively. The shape of the pressure-temperature path for subducting slabs prevents fluid release at depths above and below where these dehydration reactions occur. We conclude that abundant tremor activity requires metamorphic conditions where localised dehydration occurs during subduction, and this may explain why tremor appears more abundant in some subduction zones than others.

  8. Effects of beta-adrenergic blockers on drug-induced tremors.

    Science.gov (United States)

    Iwata, S; Nomoto, M; Fukuda, T

    1993-03-01

    We studied the effect of various kinds of beta-adrenergic blockers on oxotremorine-, harmaline- and thyrotropin-releasing hormone (TRH)-induced tremors in mice. To investigate what property of beta-blockers plays the main role in suppressing tremor, we employed five beta-blockers (propranolol, atenolol, butoxamine, pindolol, and arotinolol). All drugs suppressed oxotremorine-induced tremors but none reduced harmaline-induced tremors. Even though TRH-induced tremors were decreased significantly only by propranolol and high doses of arotinolol, all drugs had a tendency to reduce the tremor. We concluded that neuropharmacological mechanisms underlying to harmaline-induced tremors were different from those of TRH- and oxotremorine-induced tremors and that features of beta-blockers (beta 1- or beta 2-selectivity, intrinsic sympathomimetic activity, and membrane stabilizing activity) did not primarily contribute to the suppression of tremors.

  9. Quantitative Assessment of Parkinsonian Tremor Based on an Inertial Measurement Unit.

    Science.gov (United States)

    Dai, Houde; Zhang, Pengyue; Lueth, Tim C

    2015-09-29

    Quantitative assessment of parkinsonian tremor based on inertial sensors can provide reliable feedback on the effect of medication. In this regard, the features of parkinsonian tremor and its unique properties such as motor fluctuations and dyskinesia are taken into account. Least-square-estimation models are used to assess the severities of rest, postural, and action tremors. In addition, a time-frequency signal analysis algorithm for tremor state detection was also included in the tremor assessment method. This inertial sensor-based method was verified through comparison with an electromagnetic motion tracking system. Seven Parkinson's disease (PD) patients were tested using this tremor assessment system. The measured tremor amplitudes correlated well with the judgments of a neurologist (r = 0.98). The systematic analysis of sensor-based tremor quantification and the corresponding experiments could be of great help in monitoring the severity of parkinsonian tremor.

  10. Functional Ability Improved in Essential Tremor by IncobotulinumtoxinA Injections Using Kinematically Determined Biomechanical Patterns - A New Future.

    Directory of Open Access Journals (Sweden)

    Olivia Samotus

    Full Text Available Effective treatment for functional disability caused by essential tremor is a significant unmet need faced by many clinicians today. Current literature regarding focal therapy by botulinum toxin type A (BoNT-A injections uses fixed dosing regimens, which cannot be individualized, provides only limited functional benefit and unacceptable muscle weakness commonly occurs. This 38-week open label study, the longest to-date, demonstrates how kinematic technology addressed all these issues by guiding muscle selection.Participants (n = 24 were assessed at weeks 0, 6, 16, 22, 32, and 38 and injected with incobotulinumtoxinA at weeks 0, 16, and 32. Clinical assessments including UPDRS tremor items, Fahn-Tolosa-Marin (FTM tremor rating scale assessing tremor severity, writing and functional ability, quality of life questionnaire (QUEST and objective kinematic assessments were completed at every visit. Participants performed two postural and two weight-bearing scripted tasks with motion sensors placed over the wrist, elbow and shoulder joints. These sensors captured angular tremor amplitude (RMS units and acceleration joint motion that was segmented into directional components: flexion-extension (F/E, pronation-supination and radial-ulnar at the wrist, F/E at the elbow, and F/E and adduction-abduction at the shoulder. Injection parameters were determined using kinematics, followed by the clinician's determination of which muscles would contribute to the specific upper limb tremor biomechanics and dosing per participant.Multi-joint biomechanical recordings allowed individualized muscle selection and showed significant improvement in whole-arm function, FTM parts A-C scores, at week 6 which continued throughout the study. By week 38, the total FTM score statistically significantly reduced from 16.2±4.6 at week 0 to 9.5±6.3 (p<0.0005. UPDRS item 21 score rating action tremor was significantly reduced from 2.6±0.5 at week 0 to 1.6±1.1 (p = 0.01 at week 32

  11. Cognitive functions, fatigue, depression, anxiety, and sleep disturbances: assessment of nonmotor features in young patients with essential tremor.

    Science.gov (United States)

    Sengul, Yildizhan; Sengul, Hakan S; Yucekaya, Sevda K; Yucel, Selma; Bakim, Bahadir; Pazarcı, Nevin K; Özdemir, Gökhan

    2015-09-01

    There is a growing amount of evidence to suggest that besides motor features, patients with essential tremor (ET) may exhibit significant nonmotor features, such as mild cognitive deficits, fatigue, neuropsychiatric symptoms, and sleep disturbances. The goal of this study was to examine nonmotor features in young patients with ET and their impact on quality of life. 45 patients (24.55 ± 7.16 years old) with ET and 35 controls were evaluated using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Beck Depression Inventory, Beck Anxiety Scale, Fatigue Severity Scale, and Short Form-36. Cognitive functions were evaluated using the Turkish version of the Montreal Cognitive Assessment Battery (MoCA). We ruled out other possible causes of the tremor. The tremor rate was evaluated using the Fahn-Tolosa-Marin Tremor Rating Scale. Poor sleep quality, fatigue, anxiety, and depressive symptoms were more common, and MoCA total scores were lower in the patient group. Fatigue, depressive symptoms, and higher anxiety levels were seen to have a negative effect on physical and mental health. Excessive daytime sleepiness had a negative effect on physical health. There is an emerging interest in nonmotor features of ET. This study showed that even young patients have nonmotor features that decrease their quality of life. This might tell us that nonmotor symptoms could be a part of the disease in the early stages.

  12. Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor

    Directory of Open Access Journals (Sweden)

    Shah A.

    2015-09-01

    Full Text Available Deep brain stimulation (DBS, an effective surgical treatment for Essential Tremor (ET, requires test stimulations in the thalamus to find the optimum site for permanent electrode implantation. During these test stimulations, the changes in tremor are only visually evaluated. This, along with other parameters, increases the subjectivity when comparing the efficacy of different thalamic nuclei. We developed a method to quantitatively evaluate tremor during the test stimulations of DBS surgery and applied to 6 ET patients undergoing this treatment. From the quantitative data collected, we identified effective stimulation amplitudes for every test stimulation position and compared it with the ones identified visually during the surgery. We also classified the data based on the thalamic nuclei in which the center of the stimulating contact was present during test stimulations. Results indicate that, to achieve the same reduction in tremor, on average, the stimulation amplitude identified by our method was 0.6 mA lower than those identified by visual evaluation. The comparison of the different thalamic nuclei showed that stimulations in the Ventro-oral and the Intermediolateral nuclei of the thalamus result in higher reduction in tremor for similar stimulation amplitudes as the frequently targeted Ventrointermediate nucleus. We conclude that our quantitative tremor evaluation method is more sensitive than the widely used visual evaluation. Using such quantitative methods will aid in identifying the optimum target structure for patients undergoing DBS.

  13. Discrimination of Parkinsonian Tremor From Essential Tremor by Voting Between Different EMG Signal Processing Techniques

    Directory of Open Access Journals (Sweden)

    A Hossen

    2014-06-01

    Full Text Available Parkinson's disease (PD and essential tremor (ET are the two most common disorders that cause involuntary muscle shaking movements, or what is called "tremor”. PD is a neurodegenerative disease caused by the loss of dopamine receptors which control and adjust the movement of the body. On the other hand, ET is a neurological movement disorder which also causes tremors and shaking, but it is not related to dopamine receptor loss; it is simply a tremor. The differential diagnosis between these two disorders is sometimes difficult to make clinically because of the similarities of their symptoms; additionally, the available tests are complex and expensive. Thus, the objective of this paper is to discriminate between these two disorders with simpler, cheaper and easier ways by using electromyography (EMG signal processing techniques. EMG and accelerometer records of 39 patients with PD and 41 with ET were acquired from the Hospital of Kiel University in Germany and divided into a trial group and a test group. Three main techniques were applied: the wavelet-based soft-decision technique, statistical signal characterization (SSC of the spectrum of the signal, and SSC of the amplitude variation of the Hilbert transform. The first technique resulted in a discrimination efficiency of 80% on the trial set and 85% on the test set. The second technique resulted in an efficiency of 90% on the trial set and 82.5% on the test set. The third technique resulted in an 87.5% efficiency on the trial set and 65.5% efficiency on the test set. Lastly, a final vote was done to finalize the discrimination using these three techniques, and as a result of the vote, accuracies of 92.5%, 85.0% and 88.75% were obtained on the trial data, test data and total data, respectively.

  14. Non-volcanic tremor characteristics and tremor generation environment in Taiwan and a case study of their stress interaction with local earthquakes

    Science.gov (United States)

    Chao, K.; Obara, K.; Nagai, S.; Hirata, N.; Pu, H.; Peng, Z.; Hsu, Y.; Wech, A.; Ching, K.; Leu, P.; Shin, T.; Huang, B.

    2013-12-01

    Recent finding of tremor in Taiwan provides an ideal place to study tremor in collision tectonic environment and its relationship with local earthquakes. Although several studies have identified triggered and ambient tremor beneath the southern Central Range of Taiwan, a number of fundamental questions of tremor remain unclear. For example, it is still not clear whether tremor occurred in the low-angle detachment fault beneath the Central Range, or high-angle thrust fault beneath the Chaochou-Lishan fault. Here we present comprehensive study of tremor in Taiwan by utilizing two different seismic datasets. First, we applied the Waveform Envelope Correlation and Clustering (WECC) method and a spatio-temporal clustering criterion to automatically detect tremor from 2004 to 2012, using continuous data recorded by ten permanent stations operated by the Central Weather Bureau Seismic Network (CWBSN) and the Broadband Array in Taiwan for Seismology (BATS). The tremor activity in this region is characterized by frequent occurrence with short duration of 5~24 min. We found that ambient tremor surrounds an active triggered tremor source and that its spectrum is similar to that of triggered tremor but with lower amplitude, suggesting similar source mechanisms but different driving forces. We also quantified tremor activity before and after the 4 March 2010, Mw6.3 Jiashian earthquake that occurred about 20km southwest from active tremor sources. We found that maximum tremor activity occurred at around 10 days after the Jiashian mainshock and the long-term tremor rate increased 51.7% in a 14-month period, possibly caused by a static Coulomb stress increase with a maximum 20KPa around tremor sources based on the detachment fault model. Interestingly, the tremor rate started to increase about 20 days before the mainshock. We have examined the borehole dilatometer data located at ~36km northeast of the tremor sources, but found no clear change of volumetric strain before the

  15. Heterogeneity of 90Sr radioactive contamination at the head part of the East Ural radioactive trace (EURT).

    Science.gov (United States)

    Modorov, M; Seleznev, A; Mikhailovskaya, L

    2017-02-01

    1: We measured 90Sr concentrations and beta particle flux density (BPFD) in 44 soil samples collected from four soil profiles across a central transect on the head of the East Ural Radioactive Trace (EURT). The relationship between BPFD and 90Sr concentration of each soil sample can be characterised by a linear regression model; 90Sr concentration in the upper 12 cm soil layer can thus be assessed by measuring BPFD in the soil surface. 2: The BPFD on the soil surface was measured at 969 points at seven sites with linear dimensions ranging from 140 × 20 m to 140 × 320 m. The correspondence of 90Sr concentration in the 12 cm soil layer with its BPFD value was calculated for each of these seven sites. Eighty (80) % of 90Sr concentration measurements in the 12 cm soil layer in each model site differed by a factor of 2.0-5. The variability of 90Sr concentration increased significantly in the 12 cm upper soil layer over territories with visual features of landscape disturbance (pits, trenches). The ratio of maximum to minimum concentration of 90Sr varied from 6.1 to 6.6 in the 12 cm soil layer over territories without visual features of anthropogenic soil disturbance. 3: The 90Sr concentration was measured in the skeletons of 34 juvenile Microtus oeconomus individuals weighing less than 12.5 g and trapped at the four model sites in July. The assessment of 90Sr concentration in the 12 cm soil layer was conducted for each point where an animal was trapped. The relationship between 90Sr concentration in soil and in the skeleton was characterised by a linear regression model with a determination coefficient of 0.51. 4: The concentration ratio for 90Sr from soil to skeleton (CRskeleton-soil) was 2.0 ± 0.1 for M. oeconomus over the territory of the EURT, which is consistent with the minimum value of the same CRskeleton-soil for M. oeconomus from the Chernobyl area (Chesser et al., 2000). Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The occurrence of dystonia in upper-limb multiple sclerosis tremor.

    Science.gov (United States)

    Van der Walt, A; Buzzard, K; Sung, S; Spelman, T; Kolbe, S C; Marriott, M; Butzkueven, H; Evans, A

    2015-12-01

    The pathophysiology of multiple sclerosis (MS) tremor is uncertain with limited phenotypical studies available. To investigate whether dystonia contributes to MS tremor and its severity. MS patients (n = 54) with and without disabling uni- or bilateral upper limb tremor were recruited (39 limbs per group). We rated tremor severity, writing and Archimedes spiral drawing; cerebellar dysfunction (SARA score); the Global Dystonia Scale (GDS) for proximal and distal upper limbs, dystonic posturing, mirror movements, geste antagoniste, and writer's cramp. Geste antagoniste, mirror dystonia, and dystonic posturing were more frequent and severe (p tremor severity in tremor compared to non-tremor patients. A 1-unit increase in distal dystonia predicted a 0.52-Bain unit (95% confidence interval (CI) 0.08-0.97), p = 0.022) increase in tremor severity and a 1-unit (95% CI 0.48-1.6, p = 0.001) increase in drawing scores. A 1-unit increase in proximal dystonia predicted 0.93-Bain unit increase (95% CI 0.45-1.41, p tremor severity and 1.5-units (95% CI 0.62-2.41, p = 0.002) increase in the drawing score. Cerebellar function in the tremor limb and tremor severity was correlated (p tremor suggesting that MS tremor pathophysiology involves cerebello-pallido-thalamo-cortical network dysfunction. © The Author(s), 2015.

  17. Studies on orthocephalization. 10. Behaviour of the visceral part of the rat head during the first 14 days after gestation.

    Science.gov (United States)

    Vilmann, H; Moss, M L

    1987-01-01

    The present paper considers the significance of interosseous flexions of the palatal complex in the process of orthocephalization of the rat skull between birth and 7 d p.n. The study is based on a sample of 90 rats divided into 4 age groups, i.e. 0, 4, 7, and 14 d. These rats have been X-rayed, and their photographs subsequently analysed. During the studied period, the constituents of the bony palate, i.e. the horizontal part of the palatine bone, the palatal process of maxilla and the palatal part of premaxilla, increase markedly in length, but with individual differences in growth rate. There is, in the period, a marked decrease in angulation between the cranial base and the palatal plane. This means that the rat skull becomes more orthocranial. There is also a straightening (orthopalatalization) of the palate, as the angle between maxilla and premaxilla becomes more obtuse, and a marked decrease in angulation between the palatine bone and the cranial base. The patterns of angular changes suggest that the process of orthocephalization in the period between birth and 14 d p.n. primarily is a result of an upwards rotation of the palatine bone relative to the cranial base, while interosseous deflections in the palate only play a minor role.

  18. Annual modulation of non-volcanic tremor in northern Cascadia

    Science.gov (United States)

    Pollitz, Fred; Wech, Aaron G.; Kao, Honn; Burgmann, Roland

    2013-01-01

    Two catalogs of episodic tremor events in northern Cascadia, one from 2006 to 2012 and the other from 1997 to 2011, reveal two systematic patterns of tremor occurrence in southern Vancouver Island: (1) most individual events tend to occur in the third quarter of the year; (2) the number of events in prolonged episodes (i.e., episodic tremor and slip events), which generally propagate to Vancouver Island from elsewhere along the Cascadia subduction zone, is inversely correlated with the amount of precipitation that occurred in the preceding 2 months. We rationalize these patterns as the product of hydrologic loading of the crust of southern Vancouver Island and the surrounding continental region, superimposed with annual variations from oceanic tidal loading. Loading of the Vancouver Island crust in the winter (when the land surface receives ample precipitation) and unloading in the summer tends to inhibit and enhance downdip shear stress, respectively. Quantitatively, for an annually variable surface load, the predicted stress perturbation depends on mantle viscoelastic rheology. A mechanical model of downdip shear stress on the transition zone beneath Vancouver Island—driven predominantly by the annual hydrologic cycle—is consistent with the 1997–2012 tremor observations, with peak-to-peak downdip shear stress of about 0.4 kPa. This seasonal dependence of tremor occurrence appears to be restricted to southern Vancouver Island because of its unique situation as an elongated narrow-width land mass surrounded by ocean, which permits seasonal perturbations in shear stress at depth.

  19. Extending Alaska's plate boundary: tectonic tremor generated by Yakutat subduction

    Science.gov (United States)

    Wech, Aaron G.

    2016-01-01

    The tectonics of the eastern end of the Alaska-Aleutian subduction zone are complicated by the inclusion of the Yakutat microplate, which is colliding into and subducting beneath continental North America at near-Pacific-plate rates. The interaction among these plates at depth is not well understood, and further east, even less is known about the plate boundary or the source of Wrangell volcanism. The drop-off in Wadati-Benioff zone (WBZ) seismicity could signal the end of the plate boundary, the start of aseismic subduction, or a tear in the downgoing plate. Further compounding the issue is the possible presence of the Wrangell slab, which is faintly outlined by an anemic, eastward-dipping WBZ beneath the Wrangell volcanoes. In this study, I performed a search for tectonic tremor to map slow, plate-boundary slip in south-central Alaska. I identified ∼11,000 tremor epicenters, which continue 85 km east of the inferred Pacific plate edge marked by WBZ seismicity. The tremor zone coincides with the edges of the downgoing Yakutat terrane, and tremors transition from periodic to continuous behavior as they near the aseismic Wrangell slab. I interpret tremor to mark slow, semicontinuous slip occurring at the interface between the Yakutat and North America plates. The slow slip region lengthens the megathrust interface beyond the WBZ and may provide evidence for a connection between the Yakutat slab and the aseismic Wrangell slab.

  20. Intermittent bilateral coherence in physiological and essential hand tremor.

    Science.gov (United States)

    Chakraborty, Soma; Kopecká, Jana; Šprdlík, Otakar; Hoskovcová, Martina; Ulmanová, Olga; Růžička, Evžen; Zapotocky, Martin

    2017-04-01

    To investigate the prevalence and the temporal structure of bilateral coherence in physiological (PT) and essential (ET) hand tremor. Triaxial accelerometric recordings from both hands in 30 healthy subjects and 34 ET patients were analyzed using spectral coherence and wavelet coherence methods. In 12 additional healthy subjects, the relation between the hand tremor and the chest wall acceleration was evaluated using partial coherence analysis. The majority of both PT and ET subjects displayed significant bilateral coherence. While in PT, bilateral coherence was most frequently found in resting hand position (97% of subjects), in ET the prevalence was comparable for resting (54%) and postural (49%-57%) positions. In both PT and ET, epochs of strong coherence lasting several to a dozen seconds were separated by intervals of insignificant coherence. In PT, bilateral coherence at the main tremor frequency (8-12Hz) was coupled with the ballistocardiac rhythm. The oscillations of the two hands are intermittently synchronized in both PT and ET. We propose that in postural PT, bilateral coherence at the main tremor frequency arises from transient simultaneous entrainment of the left and right hand oscillations to ballistocardiac forcing. Bilateral coherence of hand kinematics provides a sensitive measure of synchronizing influences on the left and right tremor oscillators. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  1. Linking Essential Tremor to the Cerebellum: Clinical Evidence.

    Science.gov (United States)

    Benito-León, Julián; Labiano-Fontcuberta, Andrés

    2016-06-01

    Essential tremor (ET) might be a family of diseases unified by the presence of kinetic tremor, but also showing etiological, pathological, and clinical heterogeneity. In this review, we will describe the most significant clinical evidence, which suggests that ET is linked to the cerebellum. Data for this review were identified by searching PUBMED (January 1966 to May 2015) crossing the terms "essential tremor" (ET) and "cerebellum," which yielded 201 entries, 11 of which included the term "cerebellum" in the article title. This was supplemented by articles in the author's files that pertained to this topic. The wide spectrum of clinical features of ET that suggest that it originates as a cerebellar or cerebellar outflow problem include the presence of intentional tremor, gait and balance abnormalities, subtle features of dysarthria, and oculomotor abnormalities, as well as deficits in eye-hand coordination, motor learning deficits, incoordination during spiral drawing task, abnormalities in motor timing and visual reaction time, impairment of social abilities, improvement in tremor after cerebellar stroke, efficacy of deep brain stimulation (which blocks cerebellar outflow), and cognitive dysfunction. It is unlikely, however, that cerebellar dysfunction, per se, fully explains ET-associated dementia, because the cognitive deficits that have been described in patients with cerebellar lesions are generally mild. Overall, a variety of clinical findings suggest that in at least a sizable proportion of patients with ET, there is an underlying abnormality of the cerebellum and/or its pathways.

  2. Functional Ability Improved in Essential Tremor by IncobotulinumtoxinA Injections Using Kinematically Determined Biomechanical Patterns – A New Future

    Science.gov (United States)

    Samotus, Olivia; Rahimi, Fariborz; Lee, Jack; Jog, Mandar

    2016-01-01

    Objective Effective treatment for functional disability caused by essential tremor is a significant unmet need faced by many clinicians today. Current literature regarding focal therapy by botulinum toxin type A (BoNT-A) injections uses fixed dosing regimens, which cannot be individualized, provides only limited functional benefit and unacceptable muscle weakness commonly occurs. This 38-week open label study, the longest to-date, demonstrates how kinematic technology addressed all these issues by guiding muscle selection. Method Participants (n = 24) were assessed at weeks 0, 6, 16, 22, 32, and 38 and injected with incobotulinumtoxinA at weeks 0, 16, and 32. Clinical assessments including UPDRS tremor items, Fahn-Tolosa-Marin (FTM) tremor rating scale assessing tremor severity, writing and functional ability, quality of life questionnaire (QUEST) and objective kinematic assessments were completed at every visit. Participants performed two postural and two weight-bearing scripted tasks with motion sensors placed over the wrist, elbow and shoulder joints. These sensors captured angular tremor amplitude (RMS units) and acceleration joint motion that was segmented into directional components: flexion-extension (F/E), pronation-supination and radial-ulnar at the wrist, F/E at the elbow, and F/E and adduction-abduction at the shoulder. Injection parameters were determined using kinematics, followed by the clinician’s determination of which muscles would contribute to the specific upper limb tremor biomechanics and dosing per participant. Results Multi-joint biomechanical recordings allowed individualized muscle selection and showed significant improvement in whole-arm function, FTM parts A-C scores, at week 6 which continued throughout the study. By week 38, the total FTM score statistically significantly reduced from 16.2±4.6 at week 0 to 9.5±6.3 (ptremor was significantly reduced from 2.6±0.5 at week 0 to 1.6±1.1 (p = 0.01) at week 32. Quality of life (QUEST

  3. Quantitative Methods for Evaluating the Efficacy of Thalamic Deep Brain Stimulation in Patients with Essential Tremor

    Science.gov (United States)

    Wastensson, Gunilla; Holmberg, Björn; Johnels, Bo; Barregard, Lars

    2013-01-01

    Background Deep brain stimulation (DBS) of the thalamus is a safe and efficient method for treatment of disabling tremor in patient with essential tremor (ET). However, successful tremor suppression after surgery requires careful selection of stimulus parameters. Our aim was to examine the possible use of certain quantitative methods for evaluating the efficacy of thalamic DBS in ET patients in clinical practice, and to compare these methods with traditional clinical tests. Methods We examined 22 patients using the Essential Tremor Rating Scale (ETRS) and quantitative assessment of tremor with the stimulator both activated and deactivated. We used an accelerometer (CATSYS tremor Pen) for quantitative measurement of postural tremor, and a eurythmokinesimeter (EKM) to evaluate kinetic tremor in a rapid pointing task. Results The efficacy of DBS on tremor suppression was prominent irrespective of the method used. The agreement between clinical rating of postural tremor and tremor intensity as measured by the CATSYS tremor pen was relatively high (rs = 0.74). The agreement between kinetic tremor as assessed by the ETRS and the main outcome variable from the EKM test was low (rs = 0.34). The lack of agreement indicates that the EKM test is not comparable with the clinical test. Discussion Quantitative methods, such as the CATSYS tremor pen, could be a useful complement to clinical tremor assessment in evaluating the efficacy of DBS in clinical practice. Future studies should evaluate the precision of these methods and long-term impact on tremor suppression, activities of daily living (ADL) function and quality of life. PMID:24255800

  4. A neuroprosthesis for tremor management through the control of muscle co-contraction.

    Science.gov (United States)

    Gallego, Juan Álvaro; Rocon, Eduardo; Belda-Lois, Juan Manuel; Pons, José Luis

    2013-04-15

    Pathological tremor is the most prevalent movement disorder. Current treatments do not attain a significant tremor reduction in a large proportion of patients, which makes tremor a major cause of loss of quality of life. For instance, according to some estimates, 65% of those suffering from upper limb tremor report serious difficulties during daily living. Therefore, novel forms for tremor management are required. Since muscles intrinsically behave as a low pass filter, and tremor frequency is above that of volitional movements, the authors envisioned the exploitation of these properties as a means of developing a novel treatment alternative. This treatment would rely on muscle co-contraction for tremor management, similarly to the strategy employed by the intact central nervous system to stabilize a limb during certain tasks. We implemented a neuroprosthesis that regulated the level of muscle co-contraction by injecting current at a pair of antagonists through transcutaneous neurostimulation. Co-contraction was adapted to the instantaneous parameters of tremor, which were estimated from the raw recordings of a pair of solid state gyroscopes with a purposely designed adaptive algorithm. For the experimental validation, we enrolled six patients suffering from parkinsonian or essential tremor of different severity, and evaluated the effect of the neuroprosthesis during standard tasks employed for neurological examination. The neuroprosthesis attained significant attenuation of tremor (pneuroprosthesis, although there was a subtle trend towards larger attenuation of more severe tremors. Tremor frequency was not altered during neurostimulation, as expected from the central origin of Parkinson's disease and essential tremor. All patients showed a good tolerance to neurostimulation in terms of comfort and absence of pain, and some spontaneously reported that they felt that tremor was reduced when the neuroprosthesis was activated. The results presented herein demonstrate

  5. IgM-monoclonal gammopathy neuropathy and tremor: a first epidemiologic case control study.

    Science.gov (United States)

    Ahlskog, Matthew C; Kumar, Neeraj; Mauermann, Michelle L; Klein, Christopher J

    2012-07-01

    Small case series suggest tremor occurs frequently in IgM-monoclonal gammopathy of undetermined significance (IgM-MGUS) neuropathy. Epidemiologic study to confirm this association is lacking. Whether the neuropathy or another remote IgM-effect is causal remains unsettled. An IgM-MGUS neuropathy case cohort (n = 207) was compared to age, gender, and neuropathy impairment score (NIS) matched, other-cause neuropathy controls (n = 414). Tremor details were extracted from structured neurologic evaluation. All patients underwent nerve conductions. Tremor occurrence was significantly higher in IgM-MGUS case cohort (29%) than in control cohort (9.2%) (p = 0.001). In IgM-MGUS cases, tremor was associated with worse NIS (p = 0.025) and demyelinating nerve conductions (p = 0.020), but 11 of 60 (18%) IgM-MGUS cases with tremor had axonal neuropathy. In other-cause neuropathy controls, tremor was associated with axonal nerve conductions (p = 0.03) but not with NIS severity (p = 0.57). Tremor occurrence associated with older age in controls, (p = 0.004) but not in IgM-MGUS cases (p = 0.272). Most IgM-MGUS tremor cases (49/60) had a postural-kinetic tremor, 8 had rest tremor, 3 had mixed rest-action. Alternative causes of tremor was identified in 42% of IgM-MGUS cases, the most common type is inherited essential tremor 6/60 (p = 0.04). This first epidemiologic case-control study validates association between IgM-MGUS neuropathy and tremor. Among IgM-MGUS neuropathy cases, severity as well as type of neuropathy (demyelinating over axonal) correlated with tremor occurrence. IgM-MGUS paraproteinemia may increase tremor expression in persons recognized with common other risk factors for tremor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska.

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    Fee, David; Haney, Matthew M; Matoza, Robin S; Van Eaton, Alexa R; Cervelli, Peter; Schneider, David J; Iezzi, Alexandra M

    2017-01-06

    The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity. Copyright © 2017, American Association for the Advancement of Science.

  7. Subglacial discharge at tidewater glaciers revealed by seismic tremor

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    Bartholomaus, Timothy C.; Amundson, Jason M.; Walter, Jacob I.; O'Neel, Shad; West, Michael E.; Larsen, Christopher F.

    2015-01-01

    Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5–10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments.

  8. Dynamic Variability of Isometric Action Tremor in Precision Pinching

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    Tim Eakin

    2012-01-01

    Full Text Available Evolutionary development of isometric force impulse frequencies, power, and the directional concordance of changes in oscillatory tremor during performance of a two-digit force regulation task was examined. Analyses compared a patient group having tremor confounding volitional force regulation with a control group having no neuropathological diagnosis. Dependent variables for tremor varied temporally and spatially, both within individual trials and across trials, across individuals, across groups, and between digits. Particularly striking findings were magnitude increases during approaches to cue markers and shifts in the concordance phase from pinching toward rigid sway patterns as the magnitude increased. Magnitudes were significantly different among trace line segments of the task and were characterized by differences in relative force required and by the task progress with respect to cue markers for beginning, reversing force change direction, or task termination. The main systematic differences occurred during cue marker approach and were independent of trial sequence order.

  9. Essential Palatal Tremor Managed by Cognitive Behavioral Therapy

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    Tomohisa Kitamura

    2015-01-01

    Full Text Available Background. Essential palatal tremor is a disorder of unknown etiology involving involuntary movement of the uvula and soft palate. Treatment attempts including drugs or surgery have been conducted to cease the rhythmical movement. Case Report. A 55-year-old female visited our department complaining of a sudden, noticeable, intermittent, and rhythmical clicking noise in her throat for five years. Oral examination revealed rhythmical contractions of the soft palate with clicking at the frequency of 120 per min. Magnetic resonance imaging (MRI examination of the brain performed after consulting with the department of neuropathic internal medicine showed no abnormalities. Thus, essential palatal tremor was diagnosed. The symptoms improved with cognitive behavioral therapy without drugs or surgical treatments. The patient is now able to stop the rhythmical movement voluntarily. Discussion. Cognitive behavioral therapy might be suitable as first-line therapy for essential palatal tremor because the therapy is noninvasive.

  10. Laryngoscopy evaluation protocol for the differentiation of essential and dystonic voice tremor

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    Bruno Teixeira de Moraes

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Although syndromes that cause voice tremor have singular characteristics, the differential diagnosis of these diseases is a challenge because of the overlap of the existing signs and symptoms. OBJECTIVE: To develop a task-specific protocol to assess voice tremor by means of nasofibrolaryngoscopy and to identify those tasks that can distinguish between essential and dystonic tremor syndromes. METHODS: Cross-sectional study. The transnasal fiberoptic laryngoscopy protocol, which consisted of the assessment of palate, pharynx and larynx tremor during the performance of several vocal and non-vocal tasks with distinct phenomenological characteristics, was applied to 19 patients with voice tremor. Patients were diagnosed with essential or dystonic tremor according to the phenomenological characterization of each group. Once they were classified, the tasks associated with the presence of tremor in each syndrome were identified. RESULTS: The tasks that significantly contributed to the differential diagnosis between essential and dystonic tremor were /s/ production, continuous whistling and reduction of tremor in falsetto. These tasks were phenomenologically different with respect to the presence of tremor in the two syndromes. CONCLUSION: The protocol of specific tasks by means of transnasal fiberoptic laryngoscopy is a viable method to differentiate between essential and dystonic voice tremor syndromes through the following tasks: /s/ production, continuous whistling and reduction of tremor in falsetto.

  11. Tremor Detection Using Parametric and Non-Parametric Spectral Estimation Methods : A Comparison with Clinical Assessment

    NARCIS (Netherlands)

    Martinez Manzanera, Octavio; Elting, Jan Willem; van der Hoeven, Johannes H; Maurits, Natasha M

    2016-01-01

    In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a

  12. MRI-guided focused ultrasound thalamotomy in non-ET tremor syndromes.

    Science.gov (United States)

    Fasano, Alfonso; Llinas, Maheleth; Munhoz, Renato P; Hlasny, Eugen; Kucharczyk, Walter; Lozano, Andres M

    2017-08-22

    To report the 6-month single-blinded results of unilateral thalamotomy with MRI-guided focused ultrasound (MRgFUS) in patients with tremors other than essential tremor. Three patients with tremor due to Parkinson disease, 2 with dystonic tremor in the context of cervicobrachial dystonia and writer's cramp, and 1 with dystonia gene-associated tremor underwent MRgFUS targeting the ventro-intermedius nucleus (Vim) of the dominant hemisphere. The primary endpoint was the reduction of lateralized items of the Tremor Rating Scale of contralateral hemibody assessed by a blinded rater. All patients achieved a statistically significant, immediate, and sustained improvement of the contralateral tremor score by 42.2%, 52.0%, 55.9%, and 52.9% at 1 week and 1, 3, and 6 months after the procedure, respectively. All patients experienced transient side effects and 2 patients experienced persistent side effects at the time of last evaluation: hemitongue numbness and hemiparesis with hemihypoesthesia. Vim MRgFUS is a promising, incision-free, but nevertheless invasive technique to effectively treat tremors other than essential tremor. Future studies on larger samples and longer follow-up will further define its effectiveness and safety. NCT02252380. This study provides Class IV evidence that for patients with tremor not caused by essential tremor, MRgFUS of the Vim improves the tremor of the contralateral hemibody at 6 months. © 2017 American Academy of Neurology.

  13. Laryngoscopy evaluation protocol for the differentiation of essential and dystonic voice tremor.

    Science.gov (United States)

    Moraes, Bruno Teixeira de; Biase, Noemi Grigoletto de

    2016-01-01

    Although syndromes that cause voice tremor have singular characteristics, the differential diagnosis of these diseases is a challenge because of the overlap of the existing signs and symptoms. To develop a task-specific protocol to assess voice tremor by means of nasofibrolaryngoscopy and to identify those tasks that can distinguish between essential and dystonic tremor syndromes. Cross-sectional study. The transnasal fiberoptic laryngoscopy protocol, which consisted of the assessment of palate, pharynx and larynx tremor during the performance of several vocal and non-vocal tasks with distinct phenomenological characteristics, was applied to 19 patients with voice tremor. Patients were diagnosed with essential or dystonic tremor according to the phenomenological characterization of each group. Once they were classified, the tasks associated with the presence of tremor in each syndrome were identified. The tasks that significantly contributed to the differential diagnosis between essential and dystonic tremor were /s/ production, continuous whistling and reduction of tremor in falsetto. These tasks were phenomenologically different with respect to the presence of tremor in the two syndromes. The protocol of specific tasks by means of transnasal fiberoptic laryngoscopy is a viable method to differentiate between essential and dystonic voice tremor syndromes through the following tasks: /s/ production, continuous whistling and reduction of tremor in falsetto. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  14. Task force report: Scales for screening and evaluating tremor: Critique and recommendations

    NARCIS (Netherlands)

    Elble, R.; Bain, P.; Forjaz, M. Joao; Haubenberger, D.; Testa, C.; Goetz, C.G.; Leentjens, A.F.; Martinez-Martin, P.; Traon, A. Pavy-Le; Post, B.; Sampaio, C.; Stebbins, G.T.; Weintraub, D.; Schrag, A.

    2013-01-01

    The Movement Disorder Society established a task force to review rating scales for the assessment of tremor. Screening instruments used in identifying patients with tremor were also reviewed. Seven tremor severity scales, six activities of daily living (ADL)/disability scales, four quality-of-life

  15. Continental crust anisotropy measurements from tectonic tremor in Cascadia

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    Huesca-Pérez, Eduardo; Ortega, Roberto; Valenzuela, Raúl W.

    2017-05-01

    We present new observations of crustal anisotropy in the southern Cascadia fore arc from tectonic tremor. The abundance of tremor activity in Oregon and northern California during slow-slip events offers an enormous amount of information with which to measure and analyze anisotropy in the upper brittle continental crust. To accomplish this, we performed analyses of wave polarization and shear wave splitting of tectonic tremor signals by using three component broadband seismic stations. The splitting times range between 0.11 and 0.32 s and are consistent with typical values observed in the continental crust. Fast polarization azimuths are, in general, margin parallel and trend N-S, which parallels the azimuths of the maximum compressive stresses observed in this region. This pattern is likely to be controlled by the stress field. Comparatively, the anisotropic structure of fast directions observed in the northern section of the Cascadia margin is oblique with respect to the southern section of Cascadia, which, in general, trends E-W and is mainly controlled by active faulting and geological structures. Source distribution analysis using a bivariate normal distribution that expresses the distribution of tremors in a preferred direction shows that in northern California and Oregon, the population of tremors tends to distribute parallel to fast polarization azimuths and maximum compressive stresses, suggesting that both tremor propagation and anisotropy are influenced by the stress field. Results show that the anisotropy reflects an active tectonic process that involves the northward movement of the Oregon Block, which is rotating as a rigid body. In northern Cascadia, previous results of anisotropy show that the crust is undergoing a shortening process due to velocity differences between the Oregon Block and the North America plate, which is moving more slowly with respect to the Oregon Block, making it clash against Vancouver Island.

  16. Familial Aggregation of the Cerebellar Signs in Familial Essential Tremor

    Science.gov (United States)

    Louis, Elan D.; Hernandez, Nora; Chen, Karen P.; Naranjo, Kelly V.; Park, Jemin; Clark, Lorraine N.; Ottman, Ruth

    2017-01-01

    Background Although the hallmark feature of essential tremor (ET) is kinetic tremor, patients may exhibit additional motor features (e.g., intention tremor and mild gait ataxia) that are markers of an underlying abnormality of cerebellar function. ET is also a highly familial disorder, but we do not know whether the presence and expression of cerebellar signs are similar across family members. There are simply no published data. The alternative possibility is that these features are not heritable. We tested the specific hypothesis that the presence of cerebellar signs (i.e., intention tremor, tandem gait difficulty) ran in ET families. Methods ET probands and relatives enrolled in a genetic study at Yale and Columbia universities underwent a detailed videotaped neurological examination. Results There were 187 enrollees (59 probands, 128 affected relatives). In a bivariate logistic regression model, the presence of intention tremor in the proband was not a predictor of the presence of intention tremor in the relatives (odds ratio [OR] = 0.60, 95% confidence interval [CI] = 0.28–1.27, p = 0.18). In a similar model, the presence of greater tandem gait difficulty (i.e., a tandem gait score in the upper quartile) in the proband was not a predictor of the presence of such difficulty in the relatives (OR = 1.22, 95% CI = 0.41–3.66, p = 0.73). Discussion The presence of cerebellar signs did not aggregate in families with ET. In the current dataset, these did not seem to be disease features that were heritable. PMID:28176975

  17. Methodological issues in clinical drug development for essential tremor.

    Science.gov (United States)

    Carranza, Michael A; Snyder, Madeline R; Elble, Rodger J; Boutzoukas, Angelique E; Zesiewicz, Theresa A

    2012-01-01

    Essential tremor (ET) is one of the most common tremor disorders in the world. Despite this, only two medications have received Level A recommendations from the American Academy of Neurology to treat it (primidone and propranolol). Even though these medications provide relief to a large group of ET patients, up to 50% of patients are non-responders. Additional medications to treat ET are needed. This review discusses some of the methodological issues that should be addressed for quality clinical drug development in ET.

  18. Low-level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 2: proposed applications and treatment protocols

    Science.gov (United States)

    Zecha, Judith A. E. M.; Raber-Durlacher, Judith E.; Nair, Raj G.; Epstein, Joel B.; Elad, Sharon; Hamblin, Michael R.; Barasch, Andrei; Migliorati, Cesar A.; Milstein, Dan M. J.; Genot, Marie-Thérèse; Lansaat, Liset; van der Brink, Ron; Arnabat-Dominguez, Josep; van der Molen, Lisette; Jacobi, Irene; van Diessen, Judi; de Lange, Jan; Smeele, Ludi E.; Schubert, Mark M.

    2016-01-01

    Purpose There is a large body of evidence supporting the efficacy of low-level laser therapy (LLLT), more recently termed photobiomodulation (PBM) for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together with a better understanding of mechanisms involved and dosimetric parameters may lead to the management of a broader range of complications associated with HNC treatment. This could enhance patient adherence to cancer therapy, and improve quality of life and treatment outcomes. The mechanisms of action, dosimetric, and safety considerations for PBM have been reviewed in part 1. Part 2 discusses the head and neck treatment side effects for which PBM may prove to be effective. In addition, PBM parameters for each of these complications are suggested and future research directions are discussed. Methods Narrative review and presentation of PBM parameters are based on current evidence and expert opinion. Results PBM may have potential applications in the management of a broad range of side effects of (chemo)radiation therapy (CRT) in patients being treated for HNC. For OM management, optimal PBM parameters identified were as follows: wavelength, typically between 633 and 685 nm or 780–830 nm; energy density, laser or light-emitting diode (LED) output between 10 and 150 mW; dose, 2–3 J (J/cm2), and no more than 6 J/cm2 on the tissue surface treated; treatment schedule, two to three times a week up to daily; emission type, pulsed (<100 Hz); and route of delivery, intraorally and/or transcutaneously. To facilitate further studies, we propose potentially effective PBM parameters for prophylactic and therapeutic use in supportive care for dermatitis, dysphagia, dry mouth, dysgeusia, trismus, necrosis, lymphedema, and voice/speech alterations. Conclusion PBM may have a role in supportive care for a broad range of complications associated with the treatment of HNC with CRT

  19. Low-level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 2: proposed applications and treatment protocols.

    Science.gov (United States)

    Zecha, Judith A E M; Raber-Durlacher, Judith E; Nair, Raj G; Epstein, Joel B; Elad, Sharon; Hamblin, Michael R; Barasch, Andrei; Migliorati, Cesar A; Milstein, Dan M J; Genot, Marie-Thérèse; Lansaat, Liset; van der Brink, Ron; Arnabat-Dominguez, Josep; van der Molen, Lisette; Jacobi, Irene; van Diessen, Judi; de Lange, Jan; Smeele, Ludi E; Schubert, Mark M; Bensadoun, René-Jean

    2016-06-01

    There is a large body of evidence supporting the efficacy of low-level laser therapy (LLLT), more recently termed photobiomodulation (PBM) for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together with a better understanding of mechanisms involved and dosimetric parameters may lead to the management of a broader range of complications associated with HNC treatment. This could enhance patient adherence to cancer therapy, and improve quality of life and treatment outcomes. The mechanisms of action, dosimetric, and safety considerations for PBM have been reviewed in part 1. Part 2 discusses the head and neck treatment side effects for which PBM may prove to be effective. In addition, PBM parameters for each of these complications are suggested and future research directions are discussed. Narrative review and presentation of PBM parameters are based on current evidence and expert opinion. PBM may have potential applications in the management of a broad range of side effects of (chemo)radiation therapy (CRT) in patients being treated for HNC. For OM management, optimal PBM parameters identified were as follows: wavelength, typically between 633 and 685 nm or 780-830 nm; energy density, laser or light-emitting diode (LED) output between 10 and 150 mW; dose, 2-3 J (J/cm(2)), and no more than 6 J/cm(2) on the tissue surface treated; treatment schedule, two to three times a week up to daily; emission type, pulsed (<100 Hz); and route of delivery, intraorally and/or transcutaneously. To facilitate further studies, we propose potentially effective PBM parameters for prophylactic and therapeutic use in supportive care for dermatitis, dysphagia, dry mouth, dysgeusia, trismus, necrosis, lymphedema, and voice/speech alterations. PBM may have a role in supportive care for a broad range of complications associated with the treatment of HNC with CRT. The suggested PBM irradiation

  20. Mental Status Test Scores are Inversely Correlated with Tremor Severity: A Study of 161 Elderly Essential Tremor Cases

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    Elan D. Louis

    2012-07-01

    Full Text Available Background: There is an increasing awareness that patients with essential tremor (ET may exhibit non-motor features, including cognitive dysfunction. Yet there are surprisingly few data in ET on the association, if any, between cognitive dysfunction and motor dysfunction (i.e., tremor severity. Establishing links between the cognitive and motor features of ET would imply that the two share a common underlying pathogenic process. Recent neuroimaging data support this notion.Methods: ET cases were enrolled in a clinical–pathological study at Columbia University Medical Center, New York. The Folstein Mini-Mental State Examination (FMMSE and Modified Mini Mental Status Examination (mMMSE were administered. Action tremor was rated with a total tremor score (TTS.Results: There were 161 ET cases (mean age 83.9±5.7 years, median FMMSE 28, median mMMSE 50. The FMMSE and mMMSE were inversely correlated with the TTS (r = −0.22, p = 0.005; and r = −0.17, p = 0.029. The association, while statistically significant, was modest in magnitude. In linear regression models that adjusted for age, gender, and education, the association between cognitive test scores and TTS remained robust (p<0.001. After excluding 68 (42.2% cases taking ET medications with potential cognitive side effects, results remained unchanged.Conclusions: Each of the two cognitive test scores was associated with tremor severity such that greater cognitive dysfunction occurred in cases with more marked tremor. These data support recent imaging data, which suggest that the cerebellar neurodegeneration underlying ET may be involved in the expression of cognitive symptoms in ET.

  1. O terramoto de Lisboa de 1755: tremores e temores

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    María José Ferro TAVARES

    2009-11-01

    Full Text Available RESUMEN: Con anterioridad al gran terremoto de 1755 ya se habían registrado en Portugal temblores de tierra de intensidad bastante significativa. En la actualidad, las cartas sismotectónicas enseñan que tanto la región de la Gran Lisboa, como la costa sur atlántica y costa algarvia son las que presentan mayor peligrosidad sísmica. Los temblores de tierra fueron desde siempre un asunto de preocupación para la población portuguesa que habitaba estas regiones, provocando temores y fobias que fueron transmitidos de generación en generación. En el presente trabajo se procura identificar las señales de cambios o de continuidad en la población portuguesa y las reacciones ante los efectos de los terremotos que desde tiempos remotos afectaran al país. Particular atención es atribuida a las interpretaciones de raíz escatológica, las primeras que surgieron y que gradualmente fueran sustituidas en el siglo XVII por explicaciones que invocaban la existencia de causas primeras (divinas y causas segundas (naturales en la discusión de este tipo de fenómenos. Va a ser con el terremoto de Lisboa, en 1755, cuando la experimentación surge como medio de explicación, inicialmente apenas en términos retóricos, para después, a partir del siglo XIX, en términos científicos, sustentar la aparición y desarrollo de la propia sismología. En Portugal, mientras exista un copioso acervo bibliográfico en lo que concierne a las referidas explicaciones, una actitud pragmática ante los terremotos ha prevalecido siempre, en el sentido de que es siempre más importante mitigar sus efectos, particularmente los efectos en la salud pública en lo que se refiere al terremoto de Lisboa, que determinar sus causas exactas.ABSTRACT: Before the great Lisbon earthquake of 1755 the continental part of Portugal had already experienced strong, catastrophic tremors; present day seismotectonic maps show that indeed the metropolitan area of the capital city, as well as

  2. Evaluating machine learning algorithms estimating tremor severity ratings on the Bain-Findley scale

    Science.gov (United States)

    Yohanandan, Shivanthan A. C.; Jones, Mary; Peppard, Richard; Tan, Joy L.; McDermott, Hugh J.; Perera, Thushara

    2016-12-01

    Tremor is a debilitating symptom of some movement disorders. Effective treatment, such as deep brain stimulation (DBS), is contingent upon frequent clinical assessments using instruments such as the Bain-Findley tremor rating scale (BTRS). Many patients, however, do not have access to frequent clinical assessments. Wearable devices have been developed to provide patients with access to frequent objective assessments outside the clinic via telemedicine. Nevertheless, the information they report is not in the form of BTRS ratings. One way to transform this information into BTRS ratings is through linear regression models (LRMs). Another, potentially more accurate method is through machine learning classifiers (MLCs). This study aims to compare MLCs and LRMs, and identify the most accurate model that can transform objective tremor information into tremor severity ratings on the BTRS. Nine participants with upper limb tremor had their DBS stimulation amplitude varied while they performed clinical upper-extremity exercises. Tremor features were acquired using the tremor biomechanics analysis laboratory (TREMBAL). Movement disorder specialists rated tremor severity on the BTRS from video recordings. Seven MLCs and 6 LRMs transformed TREMBAL features into tremor severity ratings on the BTRS using the specialists’ ratings as training data. The weighted Cohen’s kappa ({κ\\text{w}} ) defined the models’ rating accuracy. This study shows that the Random Forest MLC was the most accurate model ({κ\\text{w}}   =  0.81) at transforming tremor information into BTRS ratings, thereby improving the clinical interpretation of tremor information obtained from wearable devices.

  3. Rapid voice tremor, or "flutter," in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Aronson, A E; Ramig, L O; Winholtz, W S; Silber, S R

    1992-06-01

    In an attempt to clarify the origin and frequency characteristics of a rapid voice tremor, or "flutter," in patients with amyotrophic lateral sclerosis (ALS), eight patients (four men and four women; ages 42 to 70 years) who had ALS and rapid voice tremor and an age- and sex-matched control group of eight subjects were asked to sustain the vowel /a/ and their voices were recorded for later analysis. Each segment of phonation was demodulated into amplitude and frequency components. From each subject's 8-second amplitude and frequency signals, a fast Fourier transform analysis was done on a 1-second segment previously identified perceptually as having the most apparent tremor or flutter. The results showed that patients with ALS had multiple combinations of levels and frequencies for amplitude and frequency modulations in comparison with control subjects, who had consistently low levels of modulations. In an attempt to quantify the tremor or flutter in ALS, amplitude and frequency modulations were not clearly or predominantly represented at one point along the spectrum. Nevertheless, these frequency and amplitude modulations are more prominent in patients with ALS than in normal subjects. The origins of these aberrant frequency and amplitude modulations in ALS patients remain obscure, although speculation is that they are of peripheral rather than central nervous system origin.

  4. Dementia in Fragile X-associated Tremor/Ataxia Syndrome

    Directory of Open Access Journals (Sweden)

    Ricardo Nitrini

    Full Text Available Abstract Fragile X-associated tremor/ataxia syndrome (FXTAS is a cause of movement disorders and cognitive decline which has probably been underdiagnosed, especially if its prevalence proves similar to those of progressive supranuclear palsy and amyotrophic lateral sclerosis. We report a case of a 74-year-old man who presented with action tremor, gait ataxia and forgetfulness. There was a family history of tremor and dementia, and one of the patient's grandsons was mentally deficient. Neuropsychological evaluation disclosed a frontal network syndrome. MRI showed hyperintensity of both middle cerebellar peduncles, a major diagnostic hallmark of FXTAS. Genetic testing revealed premutation of the FMR1 gene with an expanded (CGG90 repeat. The diagnosis of FXTAS is important for genetic counseling because the daughters of the affected individuals are at high risk of having offspring with fragile X syndrome. Tremors and cognitive decline should raise the diagnostic hypothesis of FXTAS, which MRI may subsequently reinforce, while the detection of the FMR1 premutation can confirm the condition.

  5. Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)

    Science.gov (United States)

    ... onset, and diagnostic criteria of the two conditions. Fragile X Syndrome (FXS) FXS is present (though often not diagnosed) ... long face (more common as children get older). Fragile X-associated Tremor Ataxia Syndrome (FXTAS) FXTAS develops in adulthood—usually after age ...

  6. Acoustic Characteristics of Simulated Respiratory-Induced Vocal Tremor

    Science.gov (United States)

    Lester, Rosemary A.; Story, Brad H.

    2013-01-01

    Purpose: The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor. Method: Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F[subscript 0]) for speech samples obtained by Farinella, Hixon, Hoit, Story,…

  7. Rhythmic finger tapping reveals cerebellar dysfunction in essential tremor

    NARCIS (Netherlands)

    Buijink, A. W. G.; Broersma, M.; van der Stouwe, A. M. M.; van Wingen, G. A.; Groot, P. F. C.; Speelman, J. D.; Maurits, N. M.; van Rootselaar, A. F.

    Introduction: Cerebellar circuits are hypothesized to play a central role in the pathogenesis of essential tremor. Rhythmic finger tapping is known to strongly engage the cerebellar motor circuitry. We characterize cerebellar and, more specifically, dentate nucleus function, and neural correlates of

  8. Strongly gliding harmonic tremor during the 2009 eruption of Redoubt Volcano

    Science.gov (United States)

    Hotovec, Alicia J.; Prejean, Stephanie G.; Vidale, John E.; Gomberg, Joan S.

    2013-01-01

    During the 2009 eruption of Redoubt Volcano, Alaska, gliding harmonic tremor occurred prominently before six nearly consecutive explosions during the second half of the eruptive sequence. The fundamental frequency repeatedly glided upward from harmonic tremor is not uncommon at volcanoes, tremor at such high frequencies is a rare observation. These frequencies approach or exceed the plausible upper limits of many models that have been suggested for volcanic tremor. We also analyzed the behavior of a swarm of repeating earthquakes that immediately preceded the first instance of pre-explosion gliding harmonic tremor. We find that these earthquakes share several traits with upward gliding harmonic tremor, and favor the explanation that the gliding harmonic tremor at Redoubt Volcano is created by the superposition of increasingly frequent and regular, repeating stick–slip earthquakes through the Dirac comb effect.

  9. Tremor in X-linked recessive spinal and bulbar muscular atrophy (Kennedy's disease

    Directory of Open Access Journals (Sweden)

    Francisco A. Dias

    2011-01-01

    Full Text Available OBJECTIVE: To study tremor in patients with X-linked recessive spinobulbar muscular atrophy or Kennedy's disease. METHODS: Ten patients (from 7 families with a genetic diagnosis of Kennedy's disease were screened for the presence of tremor using a standardized clinical protocol and followed up at a neurology outpatient clinic. All index patients were genotyped and showed an expanded allele in the androgen receptor gene. RESULTS: Mean patient age was 37.6 years and mean number of CAG repeats 47 (44-53. Tremor was present in 8 (80% patients and was predominantly postural hand tremor. Alcohol responsiveness was detected in 7 (88% patients with tremor, who all responded well to treatment with a β-blocker (propranolol. CONCLUSION: Tremor is a common feature in patients with Kennedy's disease and has characteristics similar to those of essential tremor.

  10. Using a smart phone as a standalone platform for detection and monitoring of pathological tremors.

    Science.gov (United States)

    Daneault, Jean-François; Carignan, Benoit; Codère, Carl Éric; Sadikot, Abbas F; Duval, Christian

    2012-01-01

    Smart phones are becoming ubiquitous and their computing capabilities are ever increasing. Consequently, more attention is geared toward their potential use in research and medical settings. For instance, their built-in hardware can provide quantitative data for different movements. Therefore, the goal of the current study was to evaluate the capabilities of a standalone smart phone platform to characterize tremor. Algorithms for tremor recording and online analysis can be implemented within a smart phone. The smart phone provides reliable time- and frequency-domain tremor characteristics. The smart phone can also provide medically relevant tremor assessments. Smart phones have the potential to provide researchers and clinicians with quantitative short- and long-term tremor assessments that are currently not easily available. A smart phone application for tremor quantification and online analysis was developed. Then, smart phone results were compared to those obtained simultaneously with a laboratory accelerometer. Finally, results from the smart phone were compared to clinical tremor assessments.

  11. Automated detection and characterization of harmonic tremor in continuous seismic data

    Science.gov (United States)

    Roman, Diana C.

    2017-06-01

    Harmonic tremor is a common feature of volcanic, hydrothermal, and ice sheet seismicity and is thus an important proxy for monitoring changes in these systems. However, no automated methods for detecting harmonic tremor currently exist. Because harmonic tremor shares characteristics with speech and music, digital signal processing techniques for analyzing these signals can be adapted. I develop a novel pitch-detection-based algorithm to automatically identify occurrences of harmonic tremor and characterize their frequency content. The algorithm is applied to seismic data from Popocatepetl Volcano, Mexico, and benchmarked against a monthlong manually detected catalog of harmonic tremor events. During a period of heightened eruptive activity from December 2014 to May 2015, the algorithm detects 1465 min of harmonic tremor, which generally precede periods of heightened explosive activity. These results demonstrate the algorithm's ability to accurately characterize harmonic tremor while highlighting the need for additional work to understand its causes and implications at restless volcanoes.

  12. Tremor Detection Using Parametric and Non-Parametric Spectral Estimation Methods: A Comparison with Clinical Assessment.

    Directory of Open Access Journals (Sweden)

    Octavio Martinez Manzanera

    Full Text Available In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a better insight into tremor. Typically, routine clinical assessment of accelerometry and electromyography data involves visual inspection by clinicians and occasionally computational analysis to obtain objective characteristics of tremor. However, for some tremor disorders these characteristics may be different during daily activity. This variability in presentation between the clinic and daily life makes a differential diagnosis more difficult. A long-term recording of tremor by accelerometry and/or electromyography in the home environment could help to give a better insight into the tremor disorder. However, an evaluation of such recordings using routine clinical standards would take too much time. We evaluated a range of techniques that automatically detect tremor segments in accelerometer data, as accelerometer data is more easily obtained in the home environment than electromyography data. Time can be saved if clinicians only have to evaluate the tremor characteristics of segments that have been automatically detected in longer daily activity recordings. We tested four non-parametric methods and five parametric methods on clinical accelerometer data from 14 patients with different tremor disorders. The consensus between two clinicians regarding the presence or absence of tremor on 3943 segments of accelerometer data was employed as reference. The nine methods were tested against this reference to identify their optimal parameters. Non-parametric methods generally performed better than parametric methods on our dataset when optimal parameters were used. However, one parametric method, employing the high frequency content of the tremor bandwidth

  13. Tremor Detection Using Parametric and Non-Parametric Spectral Estimation Methods: A Comparison with Clinical Assessment.

    Science.gov (United States)

    Martinez Manzanera, Octavio; Elting, Jan Willem; van der Hoeven, Johannes H; Maurits, Natasha M

    2016-01-01

    In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a better insight into tremor. Typically, routine clinical assessment of accelerometry and electromyography data involves visual inspection by clinicians and occasionally computational analysis to obtain objective characteristics of tremor. However, for some tremor disorders these characteristics may be different during daily activity. This variability in presentation between the clinic and daily life makes a differential diagnosis more difficult. A long-term recording of tremor by accelerometry and/or electromyography in the home environment could help to give a better insight into the tremor disorder. However, an evaluation of such recordings using routine clinical standards would take too much time. We evaluated a range of techniques that automatically detect tremor segments in accelerometer data, as accelerometer data is more easily obtained in the home environment than electromyography data. Time can be saved if clinicians only have to evaluate the tremor characteristics of segments that have been automatically detected in longer daily activity recordings. We tested four non-parametric methods and five parametric methods on clinical accelerometer data from 14 patients with different tremor disorders. The consensus between two clinicians regarding the presence or absence of tremor on 3943 segments of accelerometer data was employed as reference. The nine methods were tested against this reference to identify their optimal parameters. Non-parametric methods generally performed better than parametric methods on our dataset when optimal parameters were used. However, one parametric method, employing the high frequency content of the tremor bandwidth under consideration

  14. Rest tremor in Parkinson's disease: Body distribution and time of appearance.

    Science.gov (United States)

    Gigante, Angelo Fabio; Pellicciari, Roberta; Iliceto, Giovanni; Liuzzi, Daniele; Mancino, Paola Vincenza; Custodero, Giacomo Emanuele; Guido, Marco; Livrea, Paolo; Defazio, Giovanni

    2017-04-15

    To assess body distribution and timing of appearance of rest tremor in Parkinson's disease. Information was obtained by a computerized database containing historical information collected at the first visit and data collected during the subsequent follow-up visits. Information on rest tremor developed during the follow-up could be therefore obtained by our own observation in a proportion of patients. Among 289 patients, rest tremor was reported at disease onset in 65.4% of cases and detected at last follow-up examination in 74.4% of patients. Analysis of patients who did not report rest tremor at disease onset indicated that 26% of such patients (9% in the overall population) manifested rest tremor over the disease course. Rest tremor spread to new sites in 39% of patients who manifested rest tremor at disease onset. Regardless of tremor presentation at disease onset or during the follow-up, upper limb was the most frequent tremor localization. Over the follow-up, rest tremor developed faster in the upper limb than in other body sites. The risk of developing rest tremor during the follow-up was not affected by sex, side of motor symptom onset and site of tremor presentation. However, age of disease onset >63years was associated with an increased risk of rest tremor spread. This study provides new information about body distribution and timing of rest tremor appearance during the course of early stages of Parkinson's disease that may help clinicians in patients' counselling. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Automatic classification of sources of volcanic tremors at the Klyuchevskoy volcanic group (Kamchatka) based on the seismic network covariance matrix analysis

    Science.gov (United States)

    Soubestre, Jean; Shapiro, Nikolai M.; Seydoux, Léonard; de Rosny, Julien; Droznin, Dimitry V.; Droznina, Svetlana Ya.; Senyukov, Sergey L.; Gordeev, Evgeny I.

    2017-04-01

    Volcanic tremors may be caused by magma moving through narrow fractures, by fragmentation and pulsation of pressurized fluids within the volcano, or by escape of pressurized steam and gases from fumaroles. They present an important attribute of the volcanic unrest and their detection and characterization is used in volcano monitoring systems. The tremors might be generated within different parts of volcanoes and might characterize different types of volcanic activity. The main goal of the present study is to develop a method of automatic classification of different types (sources) of tremors based on analysis of continuous records of a network of seismographs. The proposed method is based on the analysis of eigenvalues and eigenvectors of the seismic array covariance matrix. First, we followed an approach developed by Seydoux et al. (2016) and analyzed the width of the covariance matrix eigenvalues distribution to detect time periods with strong volcanic tremors. In a next step, we analyzed the frequency-dependent eigenvectors of the covariance matrix. The eigenvectors corresponding to strongest eigenvalues can be used as fingerprints of dominating seismic sources during the period over which the covariance matrix was calculated. We applied the method to the data recorded by the permanent seismic monitoring network composed of 19 stations operated in the vicinity of the Klyuchevskoy group of volcanoes (KVG) located in Kamchatka, Russia. The KVG is composed of 13 stratovolcanoes with 3 of them (Klyuchevskoy, Bezymianny, and Tolbachik) being very active during last decades. In addition, two other active volcanoes, Shiveluch and Kizimen, are located immediately north and south of KVG. This exceptional concentration of active volcanoes provides us with a multiplicity of seismic tremor sources required to validate the method. We used 4.5 years of vertical component records by 19 stations and computed network covariance matrices from day-long windows. We then analyzed

  16. A Network Model of Local Field Potential Activity in Essential Tremor and the Impact of Deep Brain Stimulation.

    Science.gov (United States)

    Yousif, Nada; Mace, Michael; Pavese, Nicola; Borisyuk, Roman; Nandi, Dipankar; Bain, Peter

    2017-01-01

    Essential tremor (ET), a movement disorder characterised by an uncontrollable shaking of the affected body part, is often professed to be the most common movement disorder, affecting up to one percent of adults over 40 years of age. The precise cause of ET is unknown, however pathological oscillations of a network of a number of brain regions are implicated in leading to the disorder. Deep brain stimulation (DBS) is a clinical therapy used to alleviate the symptoms of a number of movement disorders. DBS involves the surgical implantation of electrodes into specific nuclei in the brain. For ET the targeted region is the ventralis intermedius (Vim) nucleus of the thalamus. Though DBS is effective for treating ET, the mechanism through which the therapeutic effect is obtained is not understood. To elucidate the mechanism underlying the pathological network activity and the effect of DBS on such activity, we take a computational modelling approach combined with electrophysiological data. The pathological brain activity was recorded intra-operatively via implanted DBS electrodes, whilst simultaneously recording muscle activity of the affected limbs. We modelled the network hypothesised to underlie ET using the Wilson-Cowan approach. The modelled network exhibited oscillatory behaviour within the tremor frequency range, as did our electrophysiological data. By applying a DBS-like input we suppressed these oscillations. This study shows that the dynamics of the ET network support oscillations at the tremor frequency and the application of a DBS-like input disrupts this activity, which could be one mechanism underlying the therapeutic benefit.

  17. Effectiveness of BoNT A in Parkinson's disease upper limb tremor management.

    Science.gov (United States)

    Rahimi, Fariborz; Bee, Carina; Debicki, Derek; Roberts, Angela C; Bapat, Priya; Jog, Mandar

    2013-09-01

    One the greatest challenges of BoNT A therapy for tremor lies in the complexity and variation of components involved in tremor movement, and the lack of objective measures to determine these components. This 3 month open-label single injection study aims to couple clinician best judgment with kinematics to improve effect of BoNT A (incobotulinumtoxinA) injection in 7 patients with upper limb Parkinson's disease (PD) tremor. Injection was guided with clinical and kinematic assessment of tremor using angular wrist position in 3 degrees of freedom: flexion/extension, pronation/supination, and radial/ulnar deviation. Overall tremor severity and change were measured by linear finger acceleration. Kinematic data from static and functional tasks demonstrate no improvement at one month post-injection, but significant improvement at two and three months. Clinical scales across UPDRS Items 20 (1, 2, 3 months post) and 21 (2 months), and spiral drawings (3 months) showed significant improvement from baseline, while line drawings did not. This study suggests injection of BoNT A as a viable focal management option for upper limb PD tremor. In addition to clinical judgment, objective quantification of tremor dynamics by kinematics may be a feasible assessment and guidance tool which can be used to optimize injection conditions for focal tremor therapy. Kinematic analysis of tremor across a variety of joints in all degrees of movement may provide important insight into tremor dynamics, allowing optimized, targeted focal therapy.

  18. Cognitive Stress Reduces the Effect of Levodopa on Parkinson's Resting Tremor.

    Science.gov (United States)

    Zach, Heidemarie; Dirkx, Michiel F; Pasman, Jaco W; Bloem, Bastiaan R; Helmich, Rick C

    2017-03-01

    Resting tremor in Parkinson's disease (PD) increases markedly during cognitive stress. Dopamine depletion in the basal ganglia is involved in the pathophysiology of resting tremor, but it is unclear whether this contribution is altered under cognitive stress. We test the hypothesis that cognitive stress modulates the levodopa effect on resting tremor. Tremulous PD patients (n = 69) were measured in two treatment conditions (OFF vs. ON levodopa) and in two behavioral contexts (rest vs. cognitive co-activation). Using accelerometry, we tested the effect of both interventions on tremor intensity and tremor variability. Levodopa significantly reduced tremor intensity (across behavioral contexts), while cognitive co-activation increased it (across treatment conditions). Crucially, the levodopa effect was significantly smaller during cognitive co-activation than during rest. Resting tremor variability increased after levodopa and decreased during cognitive co-activation. Cognitive stress reduces the levodopa effect on Parkinson's tremor. This effect may be explained by a stress-related depletion of dopamine in the basal ganglia motor circuit, by stress-related involvement of nondopaminergic mechanisms in tremor (e.g., noradrenaline), or both. Targeting these mechanisms may open new windows for treatment. Clinical tremor assessments under evoked cognitive stress (e.g., counting tasks) may avoid overestimation of treatment effects in real life. © 2017 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.

  19. Achieving work-life balance in the National Collegiate Athletic Association Division I setting, part II: perspectives from head athletic trainers

    National Research Council Canada - National Science Library

    Goodman, Ashley; Mazerolle, Stephanie M; Pitney, William A

    2015-01-01

    ... (AT) serving in a managerial or leadership role. To investigate challenges and strategies used in achieving work-life balance from the perspective of the head AT at a National Collegiate Athletic Association Division I university. Qualitative study...

  20. TECHNOLOGY OF DECREASE OF THE HEAD PART OF BLACKSMITH’S INGOT AND ITS IMPLEMENTATION IN CONDITIONS OF OOO «SSM-TJAZHKASH»

    Directory of Open Access Journals (Sweden)

    V. A. Vladov

    2010-01-01

    Full Text Available OOO «NTTs PT» offers to the enterprises, producing ingots, to apply exoteric and heat-insulating inserts for warmth keeping of the ingot head in a set with metallurgical powder blends.

  1. Inter-Rater Agreement in the Clinical Diagnosis of Essential Tremor: Data from the NEDICES-2 Pilot Study

    Directory of Open Access Journals (Sweden)

    Fernando Sierra-Hidalgo

    2014-02-01

    Full Text Available Background: Our aim was to assess the diagnostic agreement among the neurologists in the Neurological Disorders in Central Spain 2 (NEDICES‐2 study; these neurologists were assigning diagnoses of essential tremor (ET vs. no ET.Methods: Clinical histories and standardized video‐taped neurological examinations of 26 individuals (11 ET, seven Parkinson’s disease, three diagnostically unclear, four normal, one with a tremor disorder other than ET were provided to seven consultant neurologists, six neurology residents, and five neurology research fellows (18 neurologists total. For each of the 26 individuals, neurologists were asked to assign a diagnosis of “ET” or “no ET” using diagnostic criteria proposed by the Movement Disorders Society (MDS. Inter‐rater agreement was assessed both with percent concordance and non‐weighted Κ statistics. Results: Overall Κ was 0.61 (substantial agreement, with no differences between consultant neurologists (Κ = 0.60, neurology residents (Κ = 0.61, and neurology research fellows (Κ = 0.66 in subgroup analyses. Subanalyses of agreement only among those 15 subjects with a previous diagnosis of ET (11 patients and those with a previous diagnosis of being normal (four individuals showed an overall Κ of 0.51 (moderate agreement. Discussion In a population‐based epidemiological study, substantial agreement was demonstrated for the diagnosis of ET among neurologists of different levels of expertise. However, agreement was lower than that previously reported using the Washington Heights–Inwood Genetic Study of Essential Tremor criteria, and a head‐to‐head comparison is needed to assess which is the tool of choice in epidemiological research in ET.

  2. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay ...

  3. Subclinical tremor in normal controls with versus without a family history of essential tremor: data from the United States and Turkey.

    Science.gov (United States)

    Louis, E D; Dogu, O; Ottman, R

    2010-04-01

    Mild action tremor is very common in the population. One fundamental question is whether this tremor is related to the neurological disease essential tremor (ET), which occurs in a much smaller segment of the population? ET is often genetic, and variable phenotypic expression is well-documented in the literature. We determined whether normal controls who report a family history of ET have greater action tremor than normal controls who do not report such a history. Controls, enrolled in two epidemiological studies (New York and Turkey), were examined in detail and action tremor was rated using a valid and reliable clinical rating scale, resulting in a total tremor score (range 0-36). In New York, the total tremor score was higher in 44/406 (10.8%) controls who reported a family history of ET than in 362/406 controls with no such history (4.25 +/- 2.51 vs. 3.78 +/- 2.93, P = 0.02). Controls who reported a first-degree relative with ET had the highest total tremor scores. In Turkey, the total tremor score was higher in 7/89 (7.9%) controls with a family history than in 82/89 controls with no family history (3.43 +/- 4.54 vs. 1.13 +/- 2.54, P = 0.048). All affected relatives in Turkey were first-degree. These data suggest that some of the normal tremor exhibited by people in the population is likely to be subclinical, partially expressed ET and that the sphere of ET is wider than is apparent from a consideration of clinically diagnosed cases.

  4. Thalamic Ventral Intermediate Nucleus Deep Brain Stimulation for Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Alexander C. Lehn

    2017-07-01

    Full Text Available Background: Orthostatic tremor (OT was first described in 1977. It is characterized by rapid tremor of 13–18 Hz and can be recorded in the lower limbs and trunk muscles. OT remains difficult to treat, although some success has been reported with deep brain stimulation (DBS.Case Report: We report a 68-year-old male with OT who did not improve significantly after bilateral thalamic stimulation.Discussion: Although some patients were described who improved after DBS surgery, more information is needed about the effect of these treatment modalities on OT, ideally in the form of randomized trial data. 

  5. Baseline head in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Tammisto, E.; Lehtimaeki, T. (Poeyry Environment Oy, Vantaa (Finland))

    2008-11-15

    As part of the programme for the final disposal of the spent nuclear fuel, Posiva Oy investigates the prevailing hydrological conditions on Olkiluoto island. The hydrological investigations have included several kinds of hydrological tests such as measurements of hydraulic conductivity by flow logging and a double-packer tool as well as interference tests by pumping, in order to study the hydraulic connections between the drillholes. In addition, long-term monitoring of groundwater level and groundwater head as well as measurements of flow conditions in open drillholes, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff) etc. have been part of the investigation programme aiming at the characterization of the bedrock. The data have been used in the compilation of deterministic hydro-zones and hydraulic properties for numerical flow modelling to study the flow pattern on Olkiluoto island. In addition, the compiled bedrock models have been used in the planning of the repository layout and in the analyses of the transport of radionuclides and the functionality of engineered barriers. This report focuses on the measurements of groundwater head by means of multi-packers and in connection with flow loggings. The determination of the undisturbed groundwater head (baseline head) in terms of the in situ fresh water head is the main goal of this report. The density of groundwater is strongly dependent on salinity and due to the saline groundwater deep in the bedrock in Olkiluoto the term fresh water head is used instead of hydraulic head. Taking the density of groundwater into account, the gradient of the residual pressure, which actually causes groundwater flow can be calculated. The measured and calculated heads are converted into corresponding in situ fresh water heads, which correspond to the water level (metres above sea level) in the hose that runs from the packed-off section to the ground surface. This means that

  6. Altered brain network measures in patients with primary writing tremor

    Energy Technology Data Exchange (ETDEWEB)

    Lenka, Abhishek; Jhunjhunwala, Ketan Ramakant [National Institute of Mental Health and Neurosciences, Department of Clinical Neurosciences, Bangalore, Karnataka (India); National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neurology, Bangalore, Karnataka (India); Panda, Rajanikant; Saini, Jitender; Bharath, Rose Dawn [National Institute of Mental Health and Neurosciences, Department of Neuroimaging and Interventional Radiology, Bangalore, Karnataka (India); Yadav, Ravi; Pal, Pramod Kumar [National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neurology, Bangalore, Karnataka (India)

    2017-10-15

    Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writing or while adopting the hand in the writing position. The basic pathophysiology of PWT has not been fully understood. The objective of this study is to explore the alterations in the resting state functional brain connectivity, if any, in patients with PWT using graph theory-based analysis. This prospective case-control study included 10 patients with PWT and 10 age and gender matched healthy controls. All subjects underwent MRI in a 3-Tesla scanner. Several parameters of small-world functional connectivity were compared between patients and healthy controls by using graph theory-based analysis. There were no significant differences in age, handedness (all right handed), gender distribution (all were males), and MMSE scores between the patients and controls. The mean age at presentation of tremor in the patient group was 51.7 ± 8.6 years, and the mean duration of tremor was 3.5 ± 1.9 years. Graph theory-based analysis revealed that patients with PWT had significantly lower clustering coefficient and higher path length compared to healthy controls suggesting alterations in small-world architecture of the brain. The clustering coefficients were lower in PWT patients in left and right medial cerebellum, right dorsolateral prefrontal cortex (DLPFC), and left posterior parietal cortex (PPC). Patients with PWT have significantly altered small-world brain connectivity in bilateral medial cerebellum, right DLPFC, and left PPC. Further studies with larger sample size are required to confirm our results. (orig.)

  7. Different types of tremor in the human thumb.

    Science.gov (United States)

    Brown, T I; Rack, P M; Ross, H F

    1982-11-01

    1. The upper limbs of normal subjects were immobilized in a way that allowed measurement of forces and movements at the thumb interphalangeal joint without significant movement elsewhere in the limb. 2. When the subject attempted to maintain a steady flexing force at the joint against a rigid stop, the actual force showed the irregular 8-11 Hz fluctuations characteristic of a 'physiological tremor'. This force fluctuation increased when the mean flexing force increased. 3. If the subject exerted his flexing force against a light complaint spring, there was an analogous irregular 8-11 Hz movement at the joint. 4. When, however, an extra inertial load was added to the terminal phalanx, flexion against a complaint spring was often accompanied by a different type of tremor. This was a more regular oscillation, of lower frequency (3-6 Hz), and of much larger amplitude. 5. The precise frequency and amplitude of this type of tremor depended on the characteristics of the added inertia and spring, in a way that could have been predicted from the responses of the joint to an imposed sinusoidal movement (Brown, Rack & Ross, 1982a). The movement appeared to arise from re-excitation within stretch reflex pathways. 6. The irregular 8-11 Hz tremor at this joint could not be attributed to reflex re-excitation, since the responses to sinusoidal movement indicated a stretch reflex whose timing would not support a movement at that frequency. It is, however, emphasized that other joints of the hand and fingers may behave in different ways.

  8. Is there a Premotor Phase of Essential Tremor?

    Directory of Open Access Journals (Sweden)

    Abhishek Lenka

    2017-10-01

    Full Text Available Background: Essential tremor (ET is the most common tremor disorder. In addition to its hallmark feature, kinetic tremor of the upper limbs, patients may have a number of non-motor symptoms and signs (NMS. Several lines of evidence suggest that ET is a neurodegenerative disorder and certain NMS may antedate the onset of tremor. This article comprehensively reviews the evidence for the existence of a "premotor phase" of ET, and discusses plausible biological explanations and implications.Methods: A PubMed search in May 2017 identified articles for this review.Results: The existence of a premotor phase of ET gains support primarily from longitudinal data. In individuals who develop incident ET, baseline (i.e., premotor evaluations reveal greater cognitive dysfunction, a faster rate of cognitive decline, and the presence of a protective effect of education against dementia. In addition, baseline evaluations also reveal more self-reported depression, antidepressant medication use, and shorter sleep duration in individuals who eventually develop incident ET. In cross-sectional studies, certain personality traits and NMS (e.g., olfactory dysfunction also suggest the existence of a premotor phase.Discussion: There is preliminary evidence supporting the existence of a premotor phase of ET. The mechanisms are unclear; however, the presence of Lewy bodies in some ET brains in autopsy studies and involvement of multiple neural networks in ET as evident from the neuroimaging studies, are possible contributors. Most evidence is from a longitudinal cohort (Neurological Disorders of Central Spain: NEDICES; additional longitudinal studies are warranted to gain better insights into the premotor phase of ET.

  9. Use of Arotinolol Pharmacotherapy to Treat Drug-induced Tremor: A Report of Three Cases.

    Science.gov (United States)

    Lee, D B; Woo, Y S; Bahk, W M

    2015-07-01

    The aim of the present study is to demonstrate the effect of arotinolol on drug-induced tremor in psychiatric patients. This is a case study of three psychiatric patients with the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) diagnosis of major depressive disorder who were treated in inpatient or outpatient psychiatric settings with antidepressant or antipsychotics. Patients developed tremor. Arotinolol was started to treat the tremor. Drug-induced tremor almost resolved completely. No adverse effects were observed. We have presented a case series of drug-induced tremors that responded well to treatment with arotinolol, which appears to be a safe and well-tolerated drug in the dose ranges used. The possible utility of arotinolol to treat drug-induced tremor deserves attention and further investigation. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Usefulness of intermuscular coherence and cumulant analysis in the diagnosis of postural tremor.

    Science.gov (United States)

    van der Stouwe, A M M; Conway, B A; Elting, J W; Tijssen, M A J; Maurits, N M

    2015-08-01

    To investigate the potential value of two advanced EMG measures as additional diagnostic measures in the polymyographic assessment of postural upper-limb tremor. We investigated coherence as a measure of dependency between two EMG signals, and cumulant analysis to reveal patterns of synchronicity in EMG activity in muscle pairs. Eighty datasets were analyzed retrospectively, obtained from four groups: essential tremor (ET), Parkinson's disease (PD), enhanced physiological tremor (EPT), and functional tremor (FT). Intermuscular coherence was highest in the PD group (0.58), intermediate in FT (0.43) and ET (0.40), and weakest in EPT (0.16) (p=0.002). EPT patients could be distinguished by low coherence: coherence tremor. These additional measures may be helpful in diagnosing difficult tremor cases. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  11. Volcanic tremor associated with eruptive activity at Bromo volcano

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    E. Gottschämmer

    1999-06-01

    Full Text Available Three broadband stations were deployed on Bromo volcano, Indonesia, from September to December 1995. The analysis of the seismograms shows that the signals produced by the volcanic sources cover the frequency range from at least 25 Hz down to periods of several minutes and underlines, therefore, the importance of broadband recordings. Frequency analysis reveals that the signal can be divided into four domains. In the traditional frequency range of volcanic tremor (1-10 Hz sharp transitions between two distinct values of the tremor amplitude can be observed. Additional tremor signal including frequencies from 10 to 20 Hz could be found during late November and early December. Throughout the whole experiment signals with periods of some hundred seconds were observed which are interpreted as ground tilts. For these long-period signals a particle motion analysis was performed in order to estimate the source location. Depth and radius can be estimated when the source is modeled as a sudden pressure change in a sphere. The fourth frequency range lies between 0.1 and 1 Hz and is dominated by two spectral peaks which are due to marine microseism. The phase velocity and the direction of wave propagation of these signals could be determined using the tripartite-method.

  12. Evidence-based guideline update: Treatment of essential tremor

    Science.gov (United States)

    Zesiewicz, T.A.; Elble, R.J.; Louis, E.D.; Gronseth, G.S.; Ondo, W.G.; Dewey, R.B.; Okun, M.S.; Sullivan, K.L.; Weiner, W.J.

    2011-01-01

    Background: This evidence-based guideline is an update of the 2005 American Academy of Neurology practice parameter on the treatment of essential tremor (ET). Methods: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 2004 and April 2010. Results and Recommendations: Conclusions and recommendations for the use of propranolol, primidone (Level A, established as effective); alprazolam, atenolol, gabapentin (monotherapy), sotalol, topiramate (Level B, probably effective); nadolol, nimodipine, clonazepam, botulinum toxin A, deep brain stimulation, thalamotomy (Level C, possibly effective); and gamma knife thalamotomy (Level U, insufficient evidence) are unchanged from the previous guideline. Changes to conclusions and recommendations from the previous guideline include the following: 1) levetiracetam and 3,4-diaminopyridine probably do not reduce limb tremor in ET and should not be considered (Level B); 2) flunarizine possibly has no effect in treating limb tremor in ET and may not be considered (Level C); and 3) there is insufficient evidence to support or refute the use of pregabalin, zonisamide, or clozapine as treatment for ET (Level U). PMID:22013182

  13. Seismic Tremor Reveals Subglacial Discharge at Tidewater Glaciers

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    Bartholomaus, T. C.; Larsen, C. F.; O'Neel, S.; West, M. E.; Amundson, J. M.; Walter, J. I.; Catania, G. A.; Stearns, L. A.; Walker, R. T.; Sutherland, D.; Shroyer, E.; Nash, J. D.

    2014-12-01

    Subglacial discharge from the termini of tidewater glaciers drives submarine terminus melting, influences fjord circulation, erodes and redeposits subglacial sediment, and is a central component of proglacial marine ecosystems. The timing and variability of subglacial discharge can also exert a strong influence on the upstream flow of tidewater glaciers through hydrology-mediated changes in basal motion. However, a lack of observations of subglacial discharge at the ice-ocean interface hinders progress in understanding these processes and contributes to some of the largest uncertainties in sea level rise projections. Here we demonstrate that passive seismic observations collected adjacent to glaciers can meet this observational need. At tidewater and lake-terminating glaciers in Alaska and Greenland, we observe hourly to seasonal variations in low-amplitude, background seismic noise, termed glacio-hydraulic tremor. Variations in tremor amplitude correlate with discharge during the drainage of a glacially-dammed lake and reveal increases in discharge efficiency over the course of the melt season. Recordings of glacio-hydraulic tremor across a range of settings suggest widespread utility for our method. Reliable prediction of future sea level rise requires observations of subglacial discharge that elicit physical insight and can validate models. Our findings provide a platform for new understanding of ice-ocean interactions and related oceanographic, geologic, and ecological disciplines.

  14. Fentanyl bolus induces muscle tremors in sevoflurane-anaesthetized piglets.

    Science.gov (United States)

    Ringer, S K; Spielmann, N; Weiss, M; Mauch, J Y

    2016-08-01

    Intravenous fentanyl (10 mcg/kg) or saline (control) was randomly administered to 10 healthy sevoflurane-mono-anaesthetized piglets. Trembling was assessed by two blinded observers using a visual analogue scale (VAS) and a simple ordinal scale at baseline and 5 min (T5) after drug administration. If no trembling was observed at that time point, the opposite treatment was administered and piglets were re-evaluated after another 5 min (T10). Four out of five piglets showed trembling after fentanyl (T5), while none given saline showed any trembling. With fentanyl the VAS scores were significantly higher at T5 compared either with baseline or with the control treatment. Control animals received fentanyl after the 5 min evaluation and all piglets showed clear trembling afterwards. The median time after fentanyl administration until first muscle tremors was 51 (20-840) s. In summary, nine out of 10 sevoflurane-anaesthetized piglets showed muscle tremors after intravenous fentanyl. Tremors subsided over time and no specific treatment was necessary. © The Author(s) 2015.

  15. Orthostatic Tremor: An Update on a Rare Entity

    Science.gov (United States)

    Benito-León, Julián; Domingo-Santos, Ángela

    2016-01-01

    Background Orthostatic tremor (OT) remains among the most intriguing and poorly understood of movement disorders. Compared to Parkinson’s disease or even essential tremor, there are very few articles addressing more basic science issues. In this review, we will discuss the findings of main case series on OT, including data on etiology, pathophysiology, diagnostic approach, treatment strategies, and outcome. Methods Data for this review were identified by searching PUBMED (January 1966 to August 2016) for the terms “orthostatic tremor” or “shaky leg syndrome,” which yielded 219 entries. We did not exclude papers on the basis of language, country, or publication date. The electronic database searches were supplemented by articles in the authors’ files that pertained to this topic. Results Owing to its rarity, the current understanding of OT is limited and is mostly based on small case series or case reports. Despite this, a growing body of evidence indicates that OT might be a progressive condition that is clinically heterogeneous (primary vs. secondary cases) with a broader spectrum of clinical features, mainly cerebellar signs, and possible cognitive impairment and personality disturbances. Along with this, advanced neuroimaging techniques are now demonstrating distinct anatomical and functional changes, some of which are consistent with neuronal loss. Discussion OT might be a family of diseases, unified by the presence of leg tremor, but further characterized by etiological and clinical heterogeneity. More work is needed to understand the pathogenesis of this condition. PMID:27713855

  16. Slow earthquakes and low frequency tremor along the Apennines, Italy

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    F. Tronca

    2008-06-01

    Full Text Available This paper reviews the main observations on slow earthquakes and low frequency tremor made along the Apennines, the main seismic active zone of Italy. These observations have been made using a geodetic interferometer system operating since 1994 in the underground tunnel of Gran Sasso, central Italy, and an underground seismic array (UNDERSEIS operating since 2002 in the same environment. The observations made in recent years indicate that both phenomena are quite rare and apparently uncorrelated. Slow earthquakes, mainly recorded in 1997 and occasionally later, have probably been caused by the activity of a shallow fault system located near the interferometers. Until now only one tremor episode characterized by low frequency content and duration of several hours has been detected in January 2004, without any correlations with the occurrence of slow or regular earthquakes. The signal to noise ratio of this event is very low, but the results of our detailed analysis show that its frequency contents and wave field characteristics are compatible with a low frequency non volcanic tremor.

  17. Unilateral Standing Leg Tremor as the Initial Manifestation of Parkinson Disease

    OpenAIRE

    Suk Yun Kang; Sook-Keun Song; Jin-Soo Kim; Young Ho Sohn

    2009-01-01

    Background: The aim of this study was to analyze the different forms of leg tremors exhibited while standing in patients with Parkinson disease (PD), and to determine if the type of leg tremor exhibited is indicative of prognosis or treatment response in PD patients. Methods: We studied the clinical characteristics of five PD patients (all women; mean age, 59 years, range, 53–64 years) with unilateral standing leg tremor as the initial manifestation of PD, including their electrophysiological...

  18. Corticomuscular transmission of tremor signals by propriospinal neurons in Parkinson's disease.

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    Manzhao Hao

    Full Text Available Cortical oscillatory signals of single and double tremor frequencies act together to cause tremor in the peripheral limbs of patients with Parkinson's disease (PD. But the corticospinal pathway that transmits the tremor signals has not been clarified, and how alternating bursts of antagonistic muscle activations are generated from the cortical oscillatory signals is not well understood. This paper investigates the plausible role of propriospinal neurons (PN in C3-C4 in transmitting the cortical oscillatory signals to peripheral muscles. Kinematics data and surface electromyogram (EMG of tremor in forearm were collected from PD patients. A PN network model was constructed based on known neurophysiological connections of PN. The cortical efferent signal of double tremor frequencies were integrated at the PN network, whose outputs drove the muscles of a virtual arm (VA model to simulate tremor behaviors. The cortical efferent signal of single tremor frequency actuated muscle spindles. By comparing tremor data of PD patients and the results of model simulation, we examined two hypotheses regarding the corticospinal transmission of oscillatory signals in Parkinsonian tremor. Hypothesis I stated that the oscillatory cortical signals were transmitted via the mono-synaptic corticospinal pathways bypassing the PN network. The alternative hypothesis II stated that they were transmitted by way of PN multi-synaptic corticospinal pathway. Simulations indicated that without the PN network, the alternating burst patterns of antagonistic muscle EMGs could not be reliably generated, rejecting the first hypothesis. However, with the PN network, the alternating burst patterns of antagonist EMGs were naturally reproduced under all conditions of cortical oscillations. The results suggest that cortical commands of single and double tremor frequencies are further processed at PN to compute the alternating burst patterns in flexor and extensor muscles, and the

  19. Examining the motor phenotype of patients with both essential tremor and Parkinson's disease.

    OpenAIRE

    Simões, R.; A. Constantino; Gibadullina, E; Houghton, D.; Louis, E; Litvan, I.

    2012-01-01

    Previous reports have suggested that essential tremor (ET) represents a risk factor for the development of Parkinson's disease (PD). Patients with long-standing ET who develop PD tend to have a tremor-dominant subtype. To further clarify this association, we examined patients from kindreds with autosomal dominant ET who had signs of isolated PD but did not meet criteria for overlapping ET. We identified 22 patients with PD meeting these diagnostic criteria, and 90% (20 of 22) had tremor-predo...

  20. Movement induced tremor in musicians and non-musicians reflects adaptive brain plasticity.

    Science.gov (United States)

    Lee, André; Schoonderwaldt, Erwin; Chadde, Mareike; Altenmüller, Eckart

    2014-01-01

    Evidence exists that motor dexterity is associated with a higher tremor amplitude of physiological tremor. Likewise, lower frequencies are associated with motor control. So far only case reports of a higher amplitude of physiological tremor in musicians exist. Moreover, no study has investigated lower frequencies during a finger movement task in musicians who can be regarded as a model of motor expertise. We developed a model and derived three hypotheses which we investigated in this study: (1) Tremor amplitude is higher in the range of physiological tremor and (2) higher for frequency ranges of dystonic tremor in musicians compared to non-musicians; (3) there is no difference in tremor amplitude at frequencies below 4 Hz. We measured tremor during a finger flexion-extension movement in 19 musicians (age 26.5 ± 8.2 years) and 24 age matched non-musicians (age 26.5 ± 8.7). By using empirical mode decomposition in combination with a Hilbert transform we obtained the instantaneous frequency and amplitude, allowing to compare tremor amplitudes throughout the movement at various frequency ranges. We found a significantly higher tremor amplitude in musicians for physiological tremor and a tendency toward a higher amplitude during most of the movement in the frequency range of 4-8 Hz, which, however, was not significant. No difference was found in the frequency range below 4 Hz for the flexion and for almost the entire extension movement. Our results corroborate findings that the 8-12 Hz oscillatory activity plays a role in motor dexterity. However, our results do not allow for the conclusion that tremor at the frequency range of 4-8 Hz is related to either plasticity induced changes that are beneficial for motor skill development nor to maladaptive changes as, e.g., focal dystonia.

  1. Movement induced tremor in musicians and non-musicians reflects adaptive brain plasticity

    Directory of Open Access Journals (Sweden)

    André eLee

    2014-07-01

    Full Text Available Evidence exists that motor dexterity is associated with a higher tremor amplitude of physiological tremor. Likewise, lower frequencies are associated with motor control. So far only case reports of a higher amplitude of physiological tremor in musicians exist. Moreover, no study has investigated lower frequencies during a finger movement task in musicians who can be regarded as a model of motor expertise. We developed a model and derived 3 hypotheses which we investigated in this study: 1 Tremor amplitude is higher in the range of physiological tremor and 2 higher for frequency ranges of dystonic tremor in musicians compared to non-musicians; 3 there is no difference in tremor amplitude at frequencies below 4Hz. We measured tremor during a finger flexion-extension movement in 19 musicians (age 26.5±8.2 years and 24 age matched non-musicians (age 26.5±8.7. By using empirical mode decomposition in combination with a Hilbert transform we obtained the instantaneous frequency and amplitude, allowing to compare tremor amplitudes throughout the movement at various frequency ranges. We found a significantly higher tremor amplitude in musicians for physiological tremor and a tendency towards a higher amplitude during most of the movement in the frequency range of 4-8Hz , which however was not significant. No difference was found in the frequency range below 4Hz for the flexion and for almost the entire extension movement. Our results corroborate findings that the 8-12Hz oscillatory activity plays a role in motor dexterity. However, our results do not allow for the conclusion that tremor at the frequency range of 4-8Hz is related to either plasticity induced changes that are beneficial for motor skill development nor to maladaptive changes as e.g. focal dystonia.

  2. Cross-spectral analysis of physiological tremor and muscle activity; 2, Application to synchronized EMG

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    Timmer, J; Pfleger, W; Deuschl, G

    1998-01-01

    We investigate the relationship between synchronized muscle activity and tremor time series in (enhanced) physiological tremor by cross-spectral analysis. Special attention is directed to the phase spectrum and its possibilities to clarify the contribution of reflex mechanisms to physiological tremor. The phase spectra are investigated under the assumptions that the EMG synchronization was caused by a reflex, respectively a central oscillator. In comparison of these results to phase spectra of measured data we found a significant contribution of reflexes. But reflexes only modify existing peaks in the power spectrum. The main agents of physiological tremor are an efferent pace and the resonant behavior of the biomechanical system.

  3. Re-emergent tremor in Parkinson's disease: Clinical and accelerometric properties.

    Science.gov (United States)

    Aytürk, Zübeyde; Yilmaz, Rezzak; Akbostanci, M Cenk

    2017-03-01

    Re-emergent tremor (RET) and the classical parkinsonian rest tremor were considered as two different phenomena of the same central tremor circuit. However, clinical and accelerometric characteristics of these tremors were not previously compared in a single study. We evaluated disease characteristics and accelerometric measurements of two tremor types in 42 patients with Parkinson's disease. Disease specific features and accelerometric measurements of peak frequency, amplitude at peak frequency and the root mean square (RMS) amplitude of two tremor types were compared. Eighteen patients had RET and the mean latency of the RET was 9.48 (±9.2)s. Groups of only rest tremor and RET did not differ significantly in age of disease onset, disease duration and severity and mean levodopa equivalent dose. Comparison of peak frequency and amplitude at peak frequency were not different between the groups, but RMS amplitude was significantly higher in the RET group (p=0.03). RMS amplitude of RET was also correlated with disease severity (r=.48, p=0.04). These results support the previous notion that rest tremor and RET are analogue, both are triggered by the same central ossilator with RET being only the suppression of the rest tremor due to arm repositioning. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Parkinsonian rest tremor can be detected accurately based on neuronal oscillations recorded from the subthalamic nucleus.

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    Hirschmann, J; Schoffelen, J M; Schnitzler, A; van Gerven, M A J

    2017-10-01

    To investigate the possibility of tremor detection based on deep brain activity. We re-analyzed recordings of local field potentials (LFPs) from the subthalamic nucleus in 10 PD patients (12 body sides) with spontaneously fluctuating rest tremor. Power in several frequency bands was estimated and used as input to Hidden Markov Models (HMMs) which classified short data segments as either tremor-free rest or rest tremor. HMMs were compared to direct threshold application to individual power features. Applying a threshold directly to band-limited power was insufficient for tremor detection (mean area under the curve [AUC] of receiver operating characteristic: 0.64, STD: 0.19). Multi-feature HMMs, in contrast, allowed for accurate detection (mean AUC: 0.82, STD: 0.15), using four power features obtained from a single contact pair. Within-patient training yielded better accuracy than across-patient training (0.84vs. 0.78, p=0.03), yet tremor could often be detected accurately with either approach. High frequency oscillations (>200Hz) were the best performing individual feature. LFP-based markers of tremor are robust enough to allow for accurate tremor detection in short data segments, provided that appropriate statistical models are used. LFP-based markers of tremor could be useful control signals for closed-loop deep brain stimulation. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  5. White matter microstructure damage in tremor-dominant Parkinson's disease patients

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    Luo, ChunYan; Song, Wei; Chen, Qin; Yang, Jing; Shang, Hui-Fang [Sichuan University, Department of Neurology, West China Hospital, Chengdu, Sichuan (China); Gong, QiYong [Sichuan University, Huaxi MR Research Center, Department of Radiology, West China Hospital, Chengdu, Sichuan (China)

    2017-07-15

    Resting tremor is one of the cardinal motor features of Parkinson's disease (PD). Several lines of evidence suggest resting tremor may have different underlying pathophysiological processes from those of bradykinesia and rigidity. The current study aims to identify white matter microstructural abnormalities associated with resting tremor in PD. We recruited 60 patients with PD (30 with tremor-dominant PD and 30 with nontremor-dominant PD) and 26 normal controls. All participants underwent clinical assessment and diffusion tensor MRI. We used tract-based spatial statistics to investigate white matter integrity across the entire white matter tract skeleton. Compared with both healthy controls and the nontremor-dominant PD patients, the tremor-dominant PD patients were characterized by increased mean diffusivity (MD) and axial diffusivity (AD) along multiple white matter tracts, mainly involving the cerebello-thalamo-cortical (CTC) pathway. The mean AD value in clusters with significant difference was correlated with resting tremor score in the tremor-dominant PD patients. There was no significant difference between the nontremor-dominant PD patients and controls. Our results support the notion that resting tremor in PD is a distinct condition in which significant microstructural white matter changes exist and provide evidence for the involvement of the CTC in tremor genesis of PD. (orig.)

  6. Deep Brain Stimulation for the Treatment of Tremor and Ataxia Associated with Abetalipoproteinemia

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    Antonios Mammis

    2012-07-01

    Full Text Available Background: Abetalipoproteinemia is a rare disorder of fat absorption, characterized by vitamin deficiency, acanthocytosis, and neurologic symptoms including ataxia and tremor.Case Report: A 41-year-old male with abetalipoproteinemia is presented. He underwent staged bilateral thalamic deep brain stimulation (DBS for the treatment of his tremors. After DBS, the patient achieved significant improvements in his tremors, ataxia, and quality of life.Discussion: Thalamic DBS proved to be both safe and efficacious in the management of ataxia and tremors in a patient with abetalipoproteinemia. This is the first report of DBS in abetalipoproteinemia in the literature. 

  7. White matter microstructure damage in tremor-dominant Parkinson's disease patients.

    Science.gov (United States)

    Luo, ChunYan; Song, Wei; Chen, Qin; Yang, Jing; Gong, QiYong; Shang, Hui-Fang

    2017-07-01

    Resting tremor is one of the cardinal motor features of Parkinson's disease (PD). Several lines of evidence suggest resting tremor may have different underlying pathophysiological processes from those of bradykinesia and rigidity. The current study aims to identify white matter microstructural abnormalities associated with resting tremor in PD. We recruited 60 patients with PD (30 with tremor-dominant PD and 30 with nontremor-dominant PD) and 26 normal controls. All participants underwent clinical assessment and diffusion tensor MRI. We used tract-based spatial statistics to investigate white matter integrity across the entire white matter tract skeleton. Compared with both healthy controls and the nontremor-dominant PD patients, the tremor-dominant PD patients were characterized by increased mean diffusivity (MD) and axial diffusivity (AD) along multiple white matter tracts, mainly involving the cerebello-thalamo-cortical (CTC) pathway. The mean AD value in clusters with significant difference was correlated with resting tremor score in the tremor-dominant PD patients. There was no significant difference between the nontremor-dominant PD patients and controls. Our results support the notion that resting tremor in PD is a distinct condition in which significant microstructural white matter changes exist and provide evidence for the involvement of the CTC in tremor genesis of PD.

  8. Observations of two special kinds of tremor at Galeras volcano, Colombia(1989-1991

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    F. Gil-Cruz

    1999-06-01

    Full Text Available Since the reactivation of Galeras volcano in 1988 its seismic activity has been dominated by a variety of LP waveforms and tremor events. Some of these signals occurred as a response to volcanic activity. Among them, two kinds of tremor deserve special attention, Flute tremor and Spasmodic tremor. Flute tremor has a spectrum of equally spaced peaks and is associated with a quasi-steady degassing process at the top of the lava dome. It is accompanied by a flute-like sound. Its spectral features and the correlation with field observations are consistent with a model generation indicating that a crack or set of cracks are excited to resonance by the release and flow of gas through the lava dome. Spasmodic tremor is composed of several distinct LP-like events joined together by a continuous signal with lower amplitudes. Two types of spasmodic tremor may be distinguished on the basis of their spectral characteristics and field observations. Spasmodic tremor type I is apparently dominated by a mix of P, SH and Rayleigh waves as determined from preliminary polarization analysis. The source appears to be located, in a region west of the active crater. As a first approximation, Spasmodic tremor type I could be associated with magmatic intrusion process occurred in 1989-1991.

  9. The Experience of Essential Tremor Caregivers: Burden and Its Correlates

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    Sarah Morgan

    2017-08-01

    Full Text Available BackgroundEssential tremor (ET is associated with physical and cognitive impairments, as well as embarrassment, avoidance of social settings, and related difficulties that negatively impact the lives of patients. In similar disease contexts, burden on friends and relatives acting as caregivers has been noted and has well-documented implications. There has been no study examining caregiver burden related to ET.MethodsData were gathered from 55 ET participants enrolled in a clinical study and their caregivers. The Zarit Burden Interview was used to assess caregiver burden. To assess clinical features that may be associated with burden, we collected several variables including the Montreal Cognitive Assessment, self-reported tremor disability, a videotaped neurological examination, questionnaires assessing ET participants’ suffering, caregivers’ perceptions of that suffering, and both caregiver and ET participant depressive symptoms. Spearman’s correlations were performed between caregiver burden and clinical features, and we created a multivariate linear regression model predicting caregiver burden.ResultsMany ET caregivers provide little to no care and experience little to no burden. However, some caregivers (11% provide over 25 h of care/week, and 13% experience high levels of burden. Caregivers most commonly provided assistance with writing and cooking. Increased burden was associated with the ET participants’ decreased cognition, more caregiving tasks, more hours/week of caregiving activities, a longer duration of care, more ET participant falls/year, more medications taken by the ET participant, and more depressive symptoms in both the ET participant and the caregiver (all p < 0.05. ET participants’ suffering and their caregivers’ perceptions of suffering were both associated with increased burden. Neither tremor severity score nor self-reported tremor disability score was associated with increased caregiver burden. Using a

  10. Cannabinoid receptor agonism suppresses tremor, cognition disturbances and anxiety-like behaviors in a rat model of essential tremor.

    Science.gov (United States)

    Abbassian, Hassan; Esmaeili, Parisa; Tahamtan, Mahshid; Aghaei, Iraj; Vaziri, Zohreh; Sheibani, Vahid; Whalley, Benjamin J; Shabani, Mohammad

    2016-10-01

    Cognitive and motor disturbances are serious consequences of tremor induced by motor disorders. Despite a lack of effective clinical treatment, some potential therapeutic agents have been used to alleviate the cognitive symptoms in the animal models of tremor. In the current study, the effects of WIN55, 212-2 (WIN), a cannabinoid receptor (CBR) agonist, on harmaline-induced motor and cognitive impairments were studied. Adult rats were treated with WIN (0.5mg/kg; i.p.) 15min before harmaline administration (10mg/kg; ip) after which exploratory and anxiety related behaviors, and cognitive function were assessed using open-field behavior and shuttle box tests. Rats that received harmaline only exhibited a markedly reduced number of central square entries when compared to harmaline vehicle-treated controls, whereas those treated with WIN and harmaline showed a significant increase in central square entries, compared to harmaline only treated. The passive avoidance memory impairments observed in harmaline treated rats, was reversed somewhat by administration of WIN. The neuroprotective and anxiolytic effects of WIN demonstrated in the current study can be offered cannabinoid receptor (CBR) agonism as a potential neuroprotective agent in the treatment of patients with tremor that manifest mental dysfunctions. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Fragile X-associated tremor/ataxia syndrome: An under-recognised cause of tremor and ataxia.

    Science.gov (United States)

    Kalus, Sarah; King, John; Lui, Elaine; Gaillard, Frank

    2016-01-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is a progressive degenerative movement disorder resulting from a fragile X "premutation", defined as 55-200 CGG repeats in the 5'-untranslated region of the FMR1 gene. The FMR1 premutation occurs in 1/800 males and 1/250 females, with FXTAS affecting 40-45% of male and 8-16% of female premutation carriers over the age of 50. FXTAS typically presents with kinetic tremor and cerebellar ataxia. FXTAS has a classical imaging profile which, in concert with clinical manifestations and genetic testing, participates vitally in its diagnosis. The revised FXTAS diagnostic criteria include two major radiological features. The "MCP sign", referring to T2 hyperintensity in the middle cerebellar peduncle, has long been considered the radiological hallmark of FXTAS. Recently included as a major radiological criterion in the diagnosis of FXTAS is T2 hyperintensity in the splenium of the corpus callosum. Other imaging features of FXTAS include T2 hyperintensities in the pons, insula and periventricular white matter as well as generalised brain and cerebellar atrophy. FXTAS is an under-recognised and misdiagnosed entity. In patients with unexplained tremor, ataxia and cognitive decline, the presence of middle cerebellar peduncle and/or corpus callosum splenium hyperintensity should raise suspicion of FXTAS. Diagnosis of FXTAS has important implications not only for the patient but also, through genetic counselling and testing, for future generations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Feasibility of an endoscopic approach to the axillary nerve and the nerve to the long head of the triceps brachii with the help of the Da Vinci Robot.

    Science.gov (United States)

    Porto de Melo, P M; Garcia, J C; Montero, E F de Souza; Atik, T; Robert, E-G; Facca, S; Liverneaux, P-A

    2013-09-01

    Surgery to transfer the axillary nerve and the nerve of the long head of the triceps presents two obstacles: 1) the access portals are not standardized and 2) the nerves are for their larger part approached through large incisions. The goal of this study was to explore the feasibility of an endoscopic microsurgical approach. The posterior aspect of a cadaver shoulder was approached through three communicating mini-incisions. The Da Vinci robot camera was installed on a central trocart, and the instrument arms on the adjacent trocarts. A gas insufflation distended the soft tissues up to the lateral axillary space. The branches of the axillary nerve and the nerve to the long head of the triceps brachii muscle were identified. The dissection of the axillary nerve trunk and its branches was easy. The posterior humeral circumflex veins and artery were dissected as well without any difficulty. Finding the nerve to the long head of the triceps brachii was found to be more challenging because of its deeper location. Robots properties allow performing conventional microsurgery: elimination of the physiologic tremor and multiplication of the movements. They also facilitate the endoscopic approach of the peripheral nerves, as seen in our results on the terminal branches of the axillary nerve and the nerve to the long head of the triceps brachii. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  13. Shallow Low-frequency Tremor in the Hyuga-nada region, western Nankai Trough subduction zone, observed by ocean bottom seismographic experiment

    Science.gov (United States)

    Yamashita, Y.; Yakiwara, H.; Shimizu, H.; Uchida, K.; Kamizono, M.; Nakamoto, M.; Fukui, M.; Fujita, S.; Aizawa, K.; Miyamachi, H.; Hirano, S.; Umakoshi, K.; Yamada, T.; Kanehara, H.; Aoshima, T.

    2013-12-01

    The Hyuga-nada region, locating western Nankai trough, is one of the most seismically active areas in Japan. Here, the Philippine Sea Plate subducts northwestward beneath the Eurasian Plate at an approximate rate of 5-7 cm/yr [e.g., Seno et al., 1993; Miyazaki and Heki, 2001]. Interplate earthquakes with magnitudes in the range of 6.5 to 7.5 repeatedly occur at intervals of decades. In the shallower part of the plate boundary in this region, the shallow very-low frequency earthquakes (dominant frequency 10~20 s) occur [Obara and Ito, 2005; Asano et al., 2008]. The shallow part of the plate boundary zone is very important for the generation of large interplate earthquakes and following tsunami. In order to reveal the detail of microseismicity from the shallower part of the plate boundary to seismogenic zone in the Hyuga-nada region, we have conducted Ocean Bottom Seismographic experiment from May 19 until July 6, 2013. We used 12 Ocean Bottom Seismometers (OBSs) with a three-component short-period (10 OBSs: 4.5Hz, 2 OBSs: 1Hz) seismometer. All OBSs were recovered but one OBS was no data because of the technical problem of the recorder. During this experiment, many earthquakes recorded by OBSs. In addition, many low-frequency signals were also recorded. From the characteristic of the waveform and estimated source location, these are the shallow low-frequency tremor which is recorded for the first time by close-in observation the Hyuga-nada region. Here, we report the result of preliminary analysis of these shallow low-frequency tremors. The tremor activity mainly occurred from end of May to end of July 2013. Dominant frequency range of these tremors are 1-8 Hz and long duration range (10 seconds ~ a few minutes), which is same character of low-frequency tremor observed in Kii-Peninsula, Nankai trough using short-period OBSs [Obana and Kodaira, 2009]. We estimated tremor source location using envelop correlation method [Obara, 2002]. Although we estimated only a few

  14. Detection and Evaluation of Episodic Tremor and Slip on Vancouver Island with a Superconducting Gravimeter

    Science.gov (United States)

    Neumeyer, J.; Kim, J.; Kao, R.; Kabirzadeh, H.; Henton, J.; Dragert, H.

    2012-12-01

    In July 2012, the superconducting gravimeter (SG) iGrav001 was installed at the Pacific Geoscience Centre in Sidney, British Columbia, on Vancouver Island. This site is located at the northern part of the Cascadia Subduction Zone where transient surface deformation accompanied by tremor-like seismic signals has been documented with a recurrence interval of 13 to 16 months. This phenomenon, named Episodic Tremor and Slip (ETS), has been interpreted to be associated with slow slip events (silent earthquakes) on the deeper (25-45 km) part of the Cascadia Subduction Zone. Geodetically, these slip events have been indentified primarily via transient horizontal displacements at continuous GPS sites and shear-strain transients recorded by borehole strainmeters of the Plate Boundary Observatory. Absolute gravimeter (AG) measurements have also suggested coincident offsets of several μGals (10-8 m/s2) to be associated with ETS. With continuous and high resolution SG monitoring, new insights into the physical processes involved in ETS are expected. Compared to the AG measurements, continuous SG has a higher resolution in recording gravity (about 0.01μGal in time domain and 1nGal (10-11 m/s2) in frequency domain). With this increased precision and with the fundamental stability of the SG, we hope to resolve low-level gravity transients that may be indicative of mass migration. The next prolonged ETS episode in southern Vancouver Island is expected this fall and the SG will provide the first continuous, stable, high-precision gravity record for an ETS event.

  15. Oral toxicity management in head and neck cancer patients treated with chemotherapy and radiation: Dental pathologies and osteoradionecrosis (Part 1) literature review and consensus statement

    NARCIS (Netherlands)

    Buglione, Michela; Cavagnini, Roberta; Di Rosario, Federico; Sottocornola, Lara; Maddalo, Marta; Vassalli, Lucia; Grisanti, Salvatore; Salgarello, Stefano; Orlandi, Ester; Paganelli, Corrado; Majorana, Alessandra; Gastaldi, Giorgio; Bossi, Paolo; Berruti, Alfredo; Pavanato, Giovanni; Nicolai, Piero; Maroldi, Roberto; Barasch, Andrei; Russi, Elvio G.; Raber-Durlacher, Judith; Murphy, Barbara; Magrini, Stefano M.

    2016-01-01

    Radiotherapy alone or in combination with chemotherapy and/or surgery is the typical treatment for head and neck cancer patients. Acute side effects (such as oral mucositis, dermatitis, salivary changes, taste alterations, etc.), and late toxicities in particular (such as osteo-radionecrosis,

  16. Oral toxicity management in head and neck cancer patients treated with chemotherapy and radiation: Xerostomia and trismus (Part 2). Literature review and consensus statement

    NARCIS (Netherlands)

    Buglione, Michela; Cavagnini, Roberta; Di Rosario, Federico; Maddalo, Marta; Vassalli, Lucia; Grisanti, Salvatore; Salgarello, Stefano; Orlandi, Ester; Bossi, Paolo; Majorana, Alessandra; Gastaldi, Giorgio; Berruti, Alfredo; Trippa, Fabio; Nicolai, Pietro; Barasch, Andrei; Russi, Elvio G.; Raber-Durlacher, Judith; Murphy, Barbara; Magrini, Stefano M.

    2016-01-01

    Radiotherapy alone or in combination with chemotherapy and/or surgery is a well-known radical treatment for head and neck cancer patients. Nevertheless acute side effects (such as moist desquamation, skin erythema, loss of taste, mucositis etc.) and in particular late toxicities (osteoradionecrosis,

  17. Achieving work-life balance in the National Collegiate Athletic Association Division I setting, part II: perspectives from head athletic trainers.

    Science.gov (United States)

    Goodman, Ashley; Mazerolle, Stephanie M; Pitney, William A

    2015-01-01

    Work-life balance has been examined at the collegiate level from multiple perspectives except for the athletic trainer (AT) serving in a managerial or leadership role. To investigate challenges and strategies used in achieving work-life balance from the perspective of the head AT at a National Collegiate Athletic Association Division I university. Qualitative study. Web-based management system. A total of 18 head ATs (13 men, 5 women; age = 44 ± 8 years, athletic training experience = 22 ± 7 years) volunteered. Participants journaled their thoughts and experiences in response to a series of questions. To establish data credibility, we included multiple-analyst triangulation, stakeholder checks, and peer review. We used a general inductive approach to analyze the data. Two higher-order themes emerged from our analysis of the data: organizational challenges and work-life balance strategies. The organizational challenges theme contained 2 lower-order themes: lack of autonomy and role demands. The work-life balance strategies theme contained 3 lower-order themes: prioritization of commitments, strategic boundary setting, and work-family integration. Head ATs are susceptible to experiencing work-life imbalance just as ATs in nonsupervisory roles are. Although not avoidable, the causes are manageable. Head ATs are encouraged to prioritize their personal time, make efforts to spend time away from their demanding positions, and reduce the number of additional responsibilities that can impede time available to spend away from work.

  18. Evaluation of advanced turbomachinery for underground pumped hydroelectric storage. Part 3. Multistage unregulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Pistner, C.

    1980-08-01

    This is the final report in a series of three on studies of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. All three reports address Francis-type, reversible pump/turbines. The first report covered single-stage regulated units; the second report covered two-stage regulated units; the present report covers multistage unregulated units. Multistage unregulated pump/turbines offer an economically attractive option for heads of 1000 to 1500 m. The feasibility of developing such machines for capacities up to 500 MW and operating heads up to 1500 m has been evaluated. Preliminary designs have been generated for six multistage pump/turbines. The designs are for nominal capacities of 350 and 500 MW and for operating heads of 1000, 1250, and 1500 m. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost with no unsolvable problems. Efficiencies of 85.8% and 88.5% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1500-m unit. Performances of the other five machines are at least comparable, and usually better. Over a 1000 to 1500-m head range, specific $/kW costs of the pump/turbines in mid-1978 US dollars vary from 19.0 to 23.1 for the 500-MW machines, and from 21.0 to 24.1 for the 350-MW machines.

  19. Low-level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 2 : proposed applications and treatment protocols

    NARCIS (Netherlands)

    Zecha, J.A.E.M.; Raber-Durlacher, J.E.; Nair, R.G.; Epstein, J.B.; Elad, S.; Hamblin, M.R.; Barasch, A.; Migliorati, C.A.; Milstein, D.M.J.; Genot, M.T.; Lansaat, L.; van der Brink, R.; Arnabat-Dominguez, J.; van der Molen, L.; Jacobi, I.; van Diessen, J.; de Lange, J.; Smeele, L.E.; Schubert, M.M.; Bensadoun, R.J.

    2016-01-01

    Purpose There is a large body of evidence supporting the efficacy of low-level laser therapy (LLLT), more recently termed photobiomodulation (PBM) for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together

  20. Low-level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 2: proposed applications and treatment protocols

    NARCIS (Netherlands)

    Zecha, Judith A. E. M.; Raber-Durlacher, Judith E.; Nair, Raj G.; Epstein, Joel B.; Elad, Sharon; Hamblin, Michael R.; Barasch, Andrei; Migliorati, Cesar A.; Milstein, Dan M. J.; Genot, Marie-Thérèse; Lansaat, Liset; van der Brink, Ron; Arnabat-Dominguez, Josep; van der Molen, Lisette; Jacobi, Irene; van Diessen, Judi; de Lange, Jan; Smeele, Ludi E.; Schubert, Mark M.; Bensadoun, René-Jean

    2016-01-01

    There is a large body of evidence supporting the efficacy of low-level laser therapy (LLLT), more recently termed photobiomodulation (PBM) for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together with a

  1. Three-dimensional assessment of postural tremor during goal-directed aiming.

    Science.gov (United States)

    Kelleran, K J; Morrison, S; Russell, D M

    2016-12-01

    The performance of fine motor tasks which require a degree of precision can be negatively affected by physiological tremor. This study examined the effect of different aiming positions on anterior-posterior (AP), medial-lateral (ML) and vertical (VT) postural tremor. Participants were required to aim a mock handgun at a target located in front of them at eye level. Changes in AP, ML and VT tremor from the forearm and gun barrel were assessed as a function of limb (i.e., whether one or both arms were used) and upper arm position (elbow bent or extended). Tremor was recorded using triaxial accelerometers. Results showed that, across all tasks, the ML and VT tremor for any point was characterized by two frequency peaks (between 1-4 and 8-12 Hz) with amplitude increasing from proximal (forearm) to distal (gun barrel). Interestingly, irrespective of the posture adopted, ML accelerations were of greater amplitude than VT oscillations. AP oscillations were markedly smaller compared to VT and ML tremor, did not display consistent frequency peaks, and were not altered by the arm conditions. Altering the aiming posture resulted in changes in VT and ML tremor amplitude, with oscillations being greater when using a single arm as compared to when two arms were used together. Similarly, tremor amplitude was reduced when the task was performed with the elbow bent compared to the straight arm condition. Overall, these results highlight that ML oscillations make as significant a contribution to the overall tremor dynamics as those observed in the VT direction. However, the origin of ML tremor is not simply the product of voluntary adjustments to maintain aim on the target, but also exhibits features similar to the neural generated 8-12-Hz tremor seen under postural conditions.

  2. Head Lice

    Science.gov (United States)

    ... 1044-1047. Canyon, DV, Speare R, et al . “Spatial and kinetic factors for the transfer of head ... for children. Natural products can give parents false sense of safety If using a natural product or ...

  3. Nonvolcanic tremors and their correlation with slow slip events in Mexico

    Science.gov (United States)

    Kolstoglodov, V.; Shapiro, N. M.; Larson, K.; Payero, J.; Husker, A.; Santiago, L. A.; Clayton, R.; Peyrat, S.

    2009-04-01

    Significant activity of nonvolcanic tremor (NVT) has been observed in the central Mexico (Guerrero) subduction zone since 2001 when continuous seismic records became available. Albeit the quality of these records is poor, it is possible to estimate a temporal variation of energy in the range of 1-2Hz (best signal/noise ratio for the NVT), which clearly indicate the maximum of NVT energy release (En) during the 2001-2002 and 2006 large aseismic slow slip events (SSE) registered by a GPS network. In particular the En is higher for the 2001-2002 SSE which had larger surface displacements and extension than the 2006 SSE. A more detailed and accurate study of NVT activity was carried out using the data collected during the MASE experiment in Mexico. MASE consisted of 100 broad band seismometers in operation for ~2.5 years (2005-2007) along the profile oriented SSW-NNE from Acapulco, and crossing over the subduction zone for a distance of ~500 km. Epicenters and depths of individual tremor events determined using the envelope cross-correlation technique have rather large uncertainties partly originated from the essentially 2D geometry of the network. The "energy" approach is more efficient in this case because it provides an average NVT activity evolution in time and space. The data processing consists of a band pass (1-2Hz) filter of the raw 100 Hz sampled N-S component records, application a 10 min-width median filter to eliminate an effect of local seismic events and noise, and integration of the energy and normalization of daily En using an average coda amplitude from several regional earthquakes of M~5. A time-space distribution of En reveals a strong correlation between NVT energy release and 2006 SSE, which also replicates the two-phase character of this slow event and a migration of the slow slip maximum from North to South. There are also a few clear episodes of relatively high NVT energy release that do not correspond to any significant geodetic signal in GPS

  4. Nonvolcanic Tremor Activity is Highly Correlated With Slow Slip Events, Mexico

    Science.gov (United States)

    Kostoglodov, V.; Shapiro, N.; Larson, K. M.; Payero, J. S.; Husker, A.; Santiago, L. A.; Clayton, R. W.

    2008-12-01

    Significant activity of nonvolcanic tremor (NVT) has been observed in the central Mexico (Guerrero) subduction zone since 2001 when continuous seismic records became available. Although the quality of these records is poor, it is possible to estimate a temporal variation of energy in the range of 1-2Hz (best signal/noise ratio for the NVT). These clearly indicate a maximum of NVT energy release (En) during the 2001-2002 and 2006 large aseismic slow slip events (SSE) registered by the Guerrero GPS network. In particular En is higher for the 2001-2002 SSE which had larger surface displacements and extension than the 2006 SSE. A more detailed and accurate study of NVT activity was carried out using the data collected during the MASE experiment in Mexico. MASE consisted of 100 broad band seismometers in operation for ~2.5 years (2005-2007) along the profile oriented SSW-NNE from Acapulco, and crossing over the subduction zone for a distance of ~500 km. Epicenters and depths of individual tremor events determined using the envelope cross-correlation technique have rather large uncertainties, partly originated from the essentially 2D geometry of the network. The 'energy' approach is more efficient in this case because it provides an average NVT activity evolution in time and space. The data processing consists of a band pass (1-2Hz) filter of the raw 100 Hz sampled N-S component records, application a 10 min-width median filter to eliminate the effect of local seismic events and noise, and integration of the energy and normalization of daily En using an average coda amplitude from several regional earthquakes of M~5. A time-space distribution of En reveals a strong correlation between NVT energy release and the 2006 SSE, which also replicates the two-phase character of this slow event and a migration of the slow slip maximum from North to South. There are also a few clear episodes of relatively high NVT energy release that do not correspond to any significant geodetic

  5. A preliminary report on the efficacy of a dynamic jaw opening device (dynasplint trismus system) as part of the multimodal treatment of trismus in patients with head and neck cancer.

    Science.gov (United States)

    Stubblefield, Michael D; Manfield, Laura; Riedel, Elyn R

    2010-08-01

    To examine the effectiveness of a dynamic jaw opening device as part of a multimodal treatment strategy for trismus in patients with head and neck cancer. Retrospective cohort study. Tertiary care cancer center. Patients with head and neck cancer and trismus (N=20). All patients underwent assessment by a board-certified physiatrist and were referred to physical therapy for delivery of the DTS and instructed to progress use of the DTS to 30 minutes 3 times a day. Additional modalities for the treatment of trismus including pain medications and botulinum toxin injections were prescribed as clinically indicated. Change in maximal interincisal distance (MID) as documented in the medical record. The use of the DTS as part of multimodal therapy including physical therapy, pain medications, and botulinum toxin injections as deemed clinically appropriate resulted in an overall improvement of the MID from 16.5mm to 23.5mm (Ptrismus associated with head and neck cancer and its treatment. Further investigation is needed to determine the relative efficacy of the treatment modalities available for trismus including physical therapy and other jaw stretching devices.

  6. Silva as the Head

    DEFF Research Database (Denmark)

    Svabo, Connie

    2015-01-01

    The head of the performance design programme is substituted by a sister's academy delegate. this performance situation formed part of a week of semesterstart where the students and professors visited Sister's Academy, Malmø. I participated in the Sister's Academy as visiting researcher and here...

  7. Achieving Work-Life Balance in the National Collegiate Athletic Association Division I Setting, Part II: Perspectives From Head Athletic Trainers

    Science.gov (United States)

    Goodman, Ashley; Mazerolle, Stephanie M.; Pitney, William A.

    2015-01-01

    Context: Work-life balance has been examined at the collegiate level from multiple perspectives except for the athletic trainer (AT) serving in a managerial or leadership role. Objective: To investigate challenges and strategies used in achieving work-life balance from the perspective of the head AT at a National Collegiate Athletic Association Division I university. Design: Qualitative study. Setting: Web-based management system. Patients or Other Participants: A total of 18 head ATs (13 men, 5 women; age = 44 ± 8 years, athletic training experience = 22 ± 7 years) volunteered. Data Collection and Analysis: Participants journaled their thoughts and experiences in response to a series of questions. To establish data credibility, we included multiple-analyst triangulation, stakeholder checks, and peer review. We used a general inductive approach to analyze the data. Results: Two higher-order themes emerged from our analysis of the data: organizational challenges and work-life balance strategies. The organizational challenges theme contained 2 lower-order themes: lack of autonomy and role demands. The work-life balance strategies theme contained 3 lower-order themes: prioritization of commitments, strategic boundary setting, and work-family integration. Conclusions: Head ATs are susceptible to experiencing work-life imbalance just as ATs in nonsupervisory roles are. Although not avoidable, the causes are manageable. Head ATs are encouraged to prioritize their personal time, make efforts to spend time away from their demanding positions, and reduce the number of additional responsibilities that can impede time available to spend away from work. PMID:25098746

  8. Orthostatic Tremor: An Update on a Rare Entity

    Directory of Open Access Journals (Sweden)

    Julián Benito-León

    2016-09-01

    Full Text Available Background: Orthostatic tremor (OT remains among the most intriguing and poorly understood of movement disorders. Compared to Parkinson’s disease or even essential tremor, there are very few articles addressing more basic science issues. In this review, we will discuss the findings of main case series on OT, including data on etiology, pathophysiology, diagnostic approach, treatment strategies, and outcome.Methods: Data for this review were identified by searching PUBMED (January 1966 to August 2016 for the terms “orthostatic tremor” or “shaky leg syndrome,” which yielded 219 entries. We did not exclude papers on the basis of language, country, or publication date. The electronic database searches were supplemented by articles in the authors’ files that pertained to this topic.Results: Owing to its rarity, the current understanding of OT is limited and is mostly based on small case series or case reports. Despite this, a growing body of evidence indicates that OT might be a progressive condition that is clinically heterogeneous (primary vs. secondary cases with a broader spectrum of clinical features, mainly cerebellar signs, and possible cognitive impairment and personality disturbances. Along with this, advanced neuroimaging techniques are now demonstrating distinct anatomical and functional changes, some of which are consistent with neuronal loss.Discussion: OT might be a family of diseases, unified by the presence of leg tremor, but further characterized by etiological and clinical heterogeneity. More work is needed to understand the pathogenesis of this condition. 

  9. Emotion modulation of the startle reflex in essential tremor: Blunted reactivity to unpleasant and pleasant pictures.

    Science.gov (United States)

    Lafo, Jacob A; Mikos, Ania; Mangal, Paul C; Scott, Bonnie M; Trifilio, Erin; Okun, Michael S; Bowers, Dawn

    2017-01-01

    Essential tremor is a highly prevalent movement disorder characterized by kinetic tremor and mild cognitive-executive changes. These features are commonly attributed to abnormal cerebellar changes, resulting in disruption of cerebellar-thalamo-cortical networks. Less attention has been paid to alterations in basic emotion processing in essential tremor, despite known cerebellar-limbic interconnectivity. In the current study, we tested the hypothesis that a psychophysiologic index of emotional reactivity, the emotion modulated startle reflex, would be muted in individuals with essential tremor relative to controls. Participants included 19 essential tremor patients and 18 controls, who viewed standard sets of unpleasant, pleasant, and neutral pictures for six seconds each. During picture viewing, white noise bursts were binaurally presented to elicit startle eyeblinks measured over the orbicularis oculi. Consistent with past literature, controls' startle eyeblink responses were modulated according to picture valence (unpleasant > neutral > pleasant). In essential tremor participants, startle eyeblinks were not modulated by emotion. This modulation failure was not due to medication effects, nor was it due to abnormal appraisal of emotional picture content. Neuroanatomically, it remains unclear whether diminished startle modulation in essential tremor is secondary to aberrant cerebellar input to the amygdala, which is involved in priming the startle response in emotional contexts, or due to more direct disruption between the cerebellum and brainstem startle circuitry. If the former is correct, these findings may be the first to reveal dysregulation of emotional networks in essential tremor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Quantitative tremor assessment in workers with current low exposure to mercury vapor.

    Science.gov (United States)

    Wastensson, Gunilla; Lamoureux, Daniel; Sällsten, Gerd; Beuter, Anne; Barregård, Lars

    2006-01-01

    Measurement of tremor has been used in several occupational studies of workers with long-term exposure to mercury vapor (Hg(0)). Recent studies indicate an adverse effect even at relatively low exposure levels. In the present study, we used sensitive quantitative methods to assess tremor in chloralkali workers with current low exposure to Hg(0). Neurological examinations and recordings of tremor using both an accelerometer and a laser-based system were conducted in 43 mercury-exposed workers and 22 age-matched referents. The median urinary mercury concentration in exposed workers was 5.9 (1.3-25) microg/g creatinine (microg/gC), while it was 0.7 (0.2-4.1) microg/gC in referents. The mean exposure time was 15 years, and the median cumulative mercury index was 161 years x microg/gC in exposed workers. There were no differences between the exposed workers and the referents in the clinical evaluation of tremor. In the quantitative tremor tests, no associations were found with current or cumulative mercury exposure for the majority of tremor measures. There were indications that exposure to Hg(0) was associated with a lowering of tremor frequency in the non-dominant hand, and a possible interaction with smoking. The differences were small, however, and overall, this study indicates no significant adverse effects on tremor at these exposure levels.

  11. Intention tremor rated according to different finger-to-nose test protocols: a survey.

    Science.gov (United States)

    Feys, Peter G; Davies-Smith, Angela; Jones, Rosemary; Romberg, Anders; Ruutiainen, Juhani; Helsen, Werner F; Ketelaer, Pierre

    2003-01-01

    To investigate the dependence of intention tremor rating scores on different finger-to-nose test (FNT) protocols, varying in arm position and the time the finger has to be kept on the nose, and to examine their relevance to function. Observational survey. Video recordings were made while patients performed the FNTs and functional tasks such as pouring water. Three European rehabilitation centers in Belgium, Finland, and England. Twenty-six multiple sclerosis patients with intention tremor (avg age, 44.1y). Not applicable. Six examiners rated the degree of intention tremor by using the Fahn Tremor Rating Scale. Interrater reliability for rating intention tremor during the FNTs was high (kappa=.65-.74). Both the required arm position and time constraints affected the magnitude of intention tremor rating scores (mean rank, 2.27-2.95) and their functional relevance (rho=.70-.84). Intention tremor was scored the highest when the arm was lifted to 90 degrees of abduction at the shoulder and the subject was required to stabilize the finger on the nose. However, its functional relevance was lower compared with a more "functionally" executed FNT. The rating of intention tremor during the FNT depends on test instructions. A standardized protocol is needed. Copyright 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

  12. Long-term follow-up of thalamic stimulation versus thalamotomy for tremor suppression

    NARCIS (Netherlands)

    Schuurman, P. Richard; Bosch, D. Andries; Merkus, Maruschka P.; Speelman, Johannes D.

    2008-01-01

    Thalamic stimulation and thalamotomy for treatment of tremor due to Parkinson's disease, essential tremor, and multiple sclerosis were compared in a randomized trial. The symptomatic and functional outcome was studied after 5 years of follow-up. Sixty-eight patients were treated (45 Parkinson's

  13. Atypical Porcine Pestivirus: A Possible Cause of Congenital Tremor Type A-II in Newborn Piglets

    NARCIS (Netherlands)

    de Groof, Ad; Deijs, Martin; Guelen, Lars; van Grinsven, Lotte; van Os-Galdos, Laura; Vogels, Wannes; Derks, Carmen; Cruijsen, Toine; Geurts, Victor; Vrijenhoek, Mieke; Suijskens, Janneke; van Doorn, Peter; van Leengoed, Leo; Schrier, Carla; van der Hoek, Lia

    2016-01-01

    Congenital tremor type A-II in piglets has been regarded as a transmissible disease since the 1970s, possibly caused by a very recently-described virus: atypical porcine pestivirus (APPV). Here, we describe several strains of APPV in piglets with clinical signs of congenital tremor (10 of 10 farms

  14. A prospective single-blind study of Gamma Knife thalamotomy for tremor.

    Science.gov (United States)

    Witjas, Tatiana; Carron, Romain; Krack, Paul; Eusebio, Alexandre; Vaugoyeau, Marianne; Hariz, Marwan; Azulay, Jean Philippe; Régis, Jean

    2015-11-03

    To evaluate the safety and efficacy of unilateral Gamma Knife thalamotomy (GKT) for treatment of severe tremor with a prospective blinded assessment. Fifty patients (mean age: 74.5 years; 32 men) with severe refractory tremor (36 essential, 14 parkinsonian) were treated with unilateral GKT. Targeting of the ventral intermediate nucleus (Vim) was achieved with Leksell Gamma Knife with a single shot through a 4-mm collimator helmet. The prescription dose was 130 Gy. Neurologic and neuropsychological assessments including a single-blinded video assessment of the tremor severity performed by a movement disorders neurologist from another center were performed before and 12 months after treatment. MRI follow-up occurred at 3, 6, and 12 months. The upper limb tremor score improved by 54.2% on the blinded assessment (p tremor components (rest, postural, and intention) were improved. Activities of daily living were improved by 72.2%. Cognitive functions remained unchanged. Following GKT, the median delay of improvement was 5.3 months (range 1-12 months). The only side effect was a transient hemiparesis associated with excessive edema around the thalamotomy in one patient. This blinded prospective assessment demonstrates that unilateral GKT is a safe and efficient procedure for severe medically refractory tremor. Side effects were rare and transient in this study. This study provides Class IV evidence that for patients with severe refractory tremor, GKT is well tolerated and effective in reducing tremor impairment. © 2015 American Academy of Neurology.

  15. Continuous theta-burst stimulation of the primary motor cortex in essential tremor

    DEFF Research Database (Denmark)

    Hellriegel, Helge; Schulz, Eva M; Siebner, Hartwig R

    2012-01-01

    We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation.......We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation....

  16. Multicentre European study of thalamic stimulation in parkinsonian and essential tremor

    NARCIS (Netherlands)

    Limousin, P.; Speelman, J. D.; Gielen, F.; Janssens, M.

    1999-01-01

    Thalamic stimulation has been proposed to treat disabling tremor. The aims of this multicentre study were to evaluate the efficacy and the morbidity of thalamic stimulation in a large number of patients with parkinsonian or essential tremor. One hundred and eleven patients were included in the study

  17. Ambulatory monitoring of tremor and other movements before and after thalamotomy: a new quantitative technique

    NARCIS (Netherlands)

    van Someren, E. J.; van Gool, W. A.; Vonk, B. F.; Mirmiran, M.; Speelman, J. D.; Bosch, D. A.; Swaab, D. F.

    1993-01-01

    Tremor, e.g. in Parkinson patients, often shows large spontaneous fluctuations in severity over the day, to such an extent that a short observation is usually not sufficient to assess the overall severity or the effect of a treatment. Since momentary impressions of the tremor can thus be misleading,

  18. Abnormal vibration induced illusion of movement in essential tremor: evidence for abnormal muscle spindle afferent function

    OpenAIRE

    Frima, N; Grunewald, R

    2005-01-01

    Objectives: Vibration induced illusion of movement (VIIM) is abnormal in patients with idiopathic focal dystonia, an abnormality which corrects with fatigue of the vibrated muscle. Since dystonia and essential tremor sometimes coexist in families, we investigated the perception of VIIM and the effect of fatigue on VIIM in patients with essential tremor.

  19. How to tackle tremor - systematic review of the literature and diagnostic work-up

    NARCIS (Netherlands)

    Buijink, A. W. G.; Contarino, M. F.; Koelman, J. H. T. M.; Speelman, J. D.; van Rootselaar, A. F.

    2012-01-01

    Background: Tremor is the most prevalent movement disorder in clinical practice. It is defined as involuntary, rhythmic, oscillatory movements. The diagnostic process of patients with tremor can be laborious and challenging, and a clear, systematic overview of available diagnostic techniques is

  20. Achieving work-life balance in the National Collegiate Athletic Association Division I setting, part I: the role of the head athletic trainer.

    Science.gov (United States)

    Mazerolle, Stephanie M; Goodman, Ashley; Pitney, William A

    2015-01-01

    Supervisor support has been identified as key to the fulfillment of work-life balance for the athletic trainer (AT), yet limited literature exists on the perspectives of supervisors. To investigate how the head AT facilitates work-life balance among staff members within the National Collegiate Athletic Association Division I setting. Qualitative study. Web-based management system. A total of 18 head ATs (13 men, 5 women; age = 44 ± 8 years, athletic training experience = 22 ± 7 years) volunteered for an asynchronous, Web-based interview. Participants responded to a series of questions by journaling their thoughts and experiences. We included multiple-analyst triangulation, stakeholder checks, and peer review to establish data credibility. We analyzed the data via a general inductive approach. Four prevailing themes emerged from the data: modeling work-life balance, encouraging disengagement from the AT role, cooperation and community workplace, and administrative support and understanding. Head ATs at the Division I level recognized the need to promote work-life balance among their staffs. They not only were supportive of policies that promote work-life balance, including spending time away from the role of the AT and teamwork among staff members, but also modeled and practiced the strategies that they promoted.

  1. Achieving Work-Life Balance in the National Collegiate Athletic Association Division I Setting, Part I: The Role of the Head Athletic Trainer

    Science.gov (United States)

    Mazerolle, Stephanie M.; Goodman, Ashley; Pitney, William A.

    2015-01-01

    Context: Supervisor support has been identified as key to the fulfillment of work-life balance for the athletic trainer (AT), yet limited literature exists on the perspectives of supervisors. Objective: To investigate how the head AT facilitates work-life balance among staff members within the National Collegiate Athletic Association Division I setting. Design: Qualitative study. Setting: Web-based management system. Patients or Other Participants: A total of 18 head ATs (13 men, 5 women; age = 44 ± 8 years, athletic training experience = 22 ± 7 years) volunteered for an asynchronous, Web-based interview. Data Collection and Analysis: Participants responded to a series of questions by journaling their thoughts and experiences. We included multiple-analyst triangulation, stakeholder checks, and peer review to establish data credibility. We analyzed the data via a general inductive approach. Results: Four prevailing themes emerged from the data: modeling work-life balance, encouraging disengagement from the AT role, cooperation and community workplace, and administrative support and understanding. Conclusions: Head ATs at the Division I level recognized the need to promote work-life balance among their staffs. They not only were supportive of policies that promote work-life balance, including spending time away from the role of the AT and teamwork among staff members, but also modeled and practiced the strategies that they promoted. PMID:25343530

  2. Hypertrophic Olivary Degeneration and Palatal or Oculopalatal Tremor

    Directory of Open Access Journals (Sweden)

    Caroline Tilikete

    2017-06-01

    Full Text Available Hypertrophic degeneration of the inferior olive is mainly observed in patients developing palatal tremor (PT or oculopalatal tremor (OPT. This syndrome manifests as a synchronous tremor of the palate (PT and/or eyes (OPT that may also involve other muscles from the branchial arches. It is associated with hypertrophic inferior olivary degeneration that is characterized by enlarged and vacuolated neurons, increased number and size of astrocytes, severe fibrillary gliosis, and demyelination. It appears on MRI as an increased T2/FLAIR signal intensity and enlargement of the inferior olive. There are two main conditions in which hypertrophic degeneration of the inferior olive occurs. The most frequent, studied, and reported condition is the development of PT/OPT and hypertrophic degeneration of the inferior olive in the weeks or months following a structural brainstem or cerebellar lesion. This “symptomatic” condition requires a destructive lesion in the Guillain–Mollaret pathway, which spans from the contralateral dentate nucleus via the brachium conjunctivum and the ipsilateral central tegmental tract innervating the inferior olive. The most frequent etiologies of destructive lesion are stroke (hemorrhagic more often than ischemic, brain trauma, brainstem tumors, and surgical or gamma knife treatment of brainstem cavernoma. The most accepted explanation for this symptomatic PT/OPT is that denervated olivary neurons released from inhibitory inputs enlarge and develop sustained synchronized oscillations. The cerebellum then modulates/accentuates this signal resulting in abnormal motor output in the branchial arches. In a second condition, PT/OPT and progressive cerebellar ataxia occurs in patients without structural brainstem or cerebellar lesion, other than cerebellar atrophy. This syndrome of progressive ataxia and palatal tremor may be sporadic or familial. In the familial form, where hypertrophic degeneration of the inferior olive may not

  3. Orthostatic tremor responds to bilateral thalamic deep brain stimulation.

    Science.gov (United States)

    Lyons, Mark K; Behbahani, Mandana; Boucher, Orland K; Caviness, John N; Evidente, Virgilio Gerald H

    2012-01-01

    Orthostatic tremor (OT) is a disabling movement disorder manifested by postural and gait disturbance. Primarily a condition of elderly people, it can be progressive in up to 15% of patients. The primary treatments are medications that are often ineffective. A 75-year-old male presented with a 10-year history of progressive and disabling OT. He had tried various medications without significant benefits. He underwent bilateral thalamic Vim deep brain stimulation (DBS). At 30-month follow-up, he has had continued significant improvement of his OT. Bilateral thalamic DBS may be a viable option for medically refractory OT.

  4. Penentuan Karakteristik Tremor Gunungapi Semeru Jawa Timur Berdasarkan Analisis Spektral (Studi Kasus: Oktober 2015-Desember 2015

    Directory of Open Access Journals (Sweden)

    Dea Hertiara Municha

    2016-06-01

    Full Text Available Gunungapi Semeru merupakan salah satu gunung aktif di Indonesia dengan tipe erupsi vulkanian dan strombolian. Penelitian ini menggunakan data seismik digital G. Semeru yang terekam pada bulan Oktober 2015- Desember 2015. Data yang akan digunakan dalam penelitian ini yaitu data tremor vulkanik gunungapi Semeru. Penelitian ini bertujuan untuk mengetahui perubahan aktivitas vulkanik yang berdasarkan pada perubahan kegiatan tremor vulkanik. Tremor vulkanik merupakan gempa yang sering terjadi di sekitar gunungapi, gempa ini terjadi akibat aktivitas pergerakan magma ke atas di dalam gunungapi. Salah satu cara untuk mengetahui karakteristik aktivitas Gunung Semeru yaitu dengan analisis spektral. Analisis spektral ini dilakukan dengan menerapkan Fast Fourier Transform. Tujuan dari transformasi ini adalah untuk merubah sinyal dari domain waktu ke domain frekuensi sehinggal diperoleh spektrum frekuensi dari sinyal-sinyal vulkanik. Berdasarkan analisis spektral pada gunung Semeru ini didominasi tremor harmonik yang memiliki ciri-ciri bentuk sinyal puncak spektral yang teratur serta memiliki frekuensi dasar tremor harmonik berkisar 0.1 Hz-2 Hz, sedangkan frekuensi dominan tremor harmonik berkisar 0.2 Hz-3.5 Hz, serta kandungan frekuensi tremor G. Semeru tergolong rendah. Serta terjadi perubahan tertinggi frekuensi dasar dan frekuensi dominan pada stasiun Puncak. Semeru Volcano is one of the active volcanoes in Indonesia with the types of volcanian and strombolian eruptions. This research used digital seismic data of Semeru Volcano that had been recorded on October 2015 to December 2015. The data used in this research was data volcanic tremor of Semeru volcano. This study aimed to determine the changes in volcanic activities based on changes in volcanic tremor activities. Volcanic tremors are frequent earthquakes that are occurred around volcanoes, these earthquakes occurred due to magma movements upward in the volcano. One way to characterize the activity

  5. Physiological and anatomical decomposition of subthalamic neurostimulation effects in essential tremor.

    Science.gov (United States)

    Groppa, Sergiu; Herzog, Jan; Falk, Daniela; Riedel, Christian; Deuschl, Günther; Volkmann, Jens

    2014-01-01

    Postural tremor is the leading symptom in essential tremor, but in some cases intention tremor and limb ataxia emerge and can become highly disabling features. Deep brain stimulation of the thalamus or subthalamic white matter improve tremor and ataxia; however, the underlying network mechanisms are enigmatic. To elucidate the mechanisms of deep brain stimulation in essential tremor, we pursued a multimodal approach combining kinematic measures of reach-to-grasp movements, clinical assessments, physiological measures of neuronal excitability and probabilistic tractography from diffusion tensor imaging. Seven patients with essential tremor (age 62.9 ± 10.3 years, two females) received thalamic deep brain stimulation and a clinical examination of severity of limb tremor and ataxia at off stimulation, using therapeutic and supratherapeutic stimulation parameters. A reach-to-grasp task based on acoustic cues was also performed. To examine the electrical properties of target structures, we determined the chronaxie of neural elements modulated. A control group of 13 healthy subjects (age 56 ± 7.6 years, five females) underwent whole-brain diffusion tensor imaging at 3 T. Probabilistic tractography was applied in healthy subjects from seeds in cerebellum and midbrain to reconstruct the connectivity pattern of the subthalamic area. The positions of stimulation electrodes in patients were transferred into probability maps and connectivity values were correlated to clinical outcome measures. Therapeutic stimulation improved ataxia and tremor mainly during the target period of the reaching paradigm (63% reduction compared with off stimulation). Notably the acceleration (29%) and deceleration periods (41%) were improved. By contrast, supratherapeutic stimulation worsened ataxia during the deceleration period with a 55% increase of spatial variability, while maintaining near complete suppression of tremor. Chronaxie measures were in the range of rapidly-conducting myelinated

  6. Pre-Eruptive Seismic Tremor Signals During the Bardarbunga Eruption, Iceland

    Science.gov (United States)

    Eibl, Eva P. S.; Bean, Christopher J.; Vogfjörd, Kristin S.; Lokmer, Ivan; Möllhoff, Martin; Ying, Yingzi; O'Brien, Gareth; Pálsson, Finnur

    2017-04-01

    The eruption of Bardarbunga volcano in Iceland in 2014/15 was preceded by two weeks of increased seismicity, seismic tremor, deformation and superficial faulting and graben formation. Propagating seismicity at 3 to 8 km depth was interpreted as the formation of a dyke while flow of magma was inferred from modelling of geodetic signals at slightly shallower depth. We present the pre-eruptive seismic activity with a focus on seismic tremor. We analyse and locate the pre-eruptive tremor with a seismic array and an amplitude-based location method that together could resolve both lateral and upwards tremor source migration. We estimate the depth range of the source using numerical simulations and compare our results with hydrological and glaciological observations such as the formation of depressions (so called cauldrons) on the glacier surface. Our results indicate that tremor occurred pre-eruptively and can be linked to the gradual opening of the shallow crust shortly before an eruption started.

  7. Effect of zonisamide on essential tremor: a pilot crossover study in comparison with arotinolol.

    Science.gov (United States)

    Morita, Shuhei; Miwa, Hideto; Kondo, Tomoyoshi

    2005-03-01

    We performed a pilot, crossover trial of zonisamide (ZNS) on essential tremor patients. Patients were randomly selected to start either ZNS or arotinolol treatment for 2 weeks. After a washout period, the patients were switched to an alternative drug. The assessment of tremor was carried out using the Fahn-Tolosa-Marin's clinical rating scale for tremor at baseline and 2 weeks after administration of each drug. There was a significant improvement after ZNS and arotinolol administration compared with the baseline. There was no significant difference in the antitremor effect between ZNS and arotinolol; however, ZNS was more effective for tremors of cranial nerve areas. Although the number of enrolled patients was limited in the present study, this open-label pilot study suggests that ZNS may have a therapeutic potential for essential tremor. A controlled trial of this drug in the future would be valuable.

  8. Design and validation of a neuroprosthesis for the treatment of upper limb tremor.

    Science.gov (United States)

    Gallego, J A; Rocon, E; Belda-Lois, J M; Koutsou, A D; Mena, S; Castillo, A; Pons, J L

    2013-01-01

    Pathological tremor is the most prevalent movement disorder. In spite of the existence of various treatments for it, tremor poses a functional problem to a large proportion of patients. This paper presents the design and implementation of a novel neuroprosthesis for tremor management. The paper starts by reviewing a series of design criteria that were established after analyzing users needs and the expected functionality of the system. Then, it summarizes the design of the neuroprosthesis, which was built to meet the criteria defined previously. Experimental results with a representative group of 12 patients show that the neuroprosthesis provided significant (p < 0.001) and systematic tremor attenuation (in average 52.33 ± 25.48 %), and encourage its functional evaluation as a potential new treatment for tremor in a large cohort of patients.

  9. Tremor-genic slow slip regions may be deeper and warmer and may slip slower than non-tremor-genic regions

    Science.gov (United States)

    Montgomery-Brown, Emily; Syracuse, Ellen M.

    2015-01-01

    Slow slip events (SSEs) are observed worldwide and often coincide with tectonic tremor. Notable examples of SSEs lacking observed tectonic tremor, however, occur beneath Kīlauea Volcano, Hawaii, the Boso Peninsula, Japan, near San Juan Bautista on the San Andreas Fault, California, and recently in Central Ecuador. These SSEs are similar to other worldwide SSEs in many ways (e.g., size or duration), but lack the concurrent tectonic tremor observed elsewhere; instead, they trigger swarms of regular earthquakes. We investigate the physical conditions that may distinguish these non-tremor-genic SSEs from those associated with tectonic tremor, including slip velocity, pressure, temperature, fluids, and fault asperities, although we cannot eliminate the possibility that tectonic tremor may be obscured in highly attenuating regions. Slip velocities of SSEs at Kīlauea Volcano (∼10−6 m/s) and Boso Peninsula (∼10−7 m/s) are among the fastest SSEs worldwide. Kīlauea Volcano, the Boso Peninsula, and Central Ecuador are also among the shallowest SSEs worldwide, and thus have lower confining pressures and cooler temperatures in their respective slow slip zones. Fluids also likely contribute to tremor generation, and no corresponding zone of high vp/vs has been noted at Kīlauea or Boso. We suggest that the relatively faster slip velocities at Kīlauea Volcano and the Boso Peninsula result from specific physical conditions that may also be responsible for triggering swarms of regular earthquakes adjacent to the slow slip, while different conditions produce slower SSE velocities elsewhere and trigger tectonic tremor.

  10. Tremors in white rhinoceroses (Ceratotherium simum during etorphine–azaperone immobilisation

    Directory of Open Access Journals (Sweden)

    Stephanie S. de Lange

    2017-01-01

    Full Text Available Little is known about the mechanisms causing tremors during immobilisation of rhinoceros and whether cardiorespiratory supportive interventions alter their intensity. Therefore, we set out to determine the possible mechanisms that lead to muscle tremors and ascertain whether cardiorespiratory supportive interventions affect tremor intensity. We studied tremors and physiological responses during etorphine–azaperone immobilisation in eight boma-held and 14 free-living white rhinoceroses. Repeated measures analysis of variance and a Friedman test were used to determine differences in variables over time and between interventions. Spearman and Pearson correlations were used to test for associations between variables. Tremor intensity measured objectively by activity loggers correlated well (p < 0.0001; r2 = 0.9 with visual observations. Tremor intensity was greatest when animals were severely hypoxaemic and acidaemic. Tremor intensity correlated strongly and negatively with partial pressure of oxygen (PaO2 (p = 0.0003; r2 = 0.9995 and potential of hydrogen (pH (p = 0.02, r2 = 0.97. It correlated strongly and positively with adrenaline concentrations (p = 0.003; r2 = 0.96, and adrenaline correlated strongly and negatively with PaO2 (p = 0.03; r2 = 0.95 and pH (p = 0.03; r2 = 0.94. Therefore, hypoxaemia and acidaemia were likely associated with the intensity of tremors through their activation of the release of tremorgenic levels of adrenaline. Tremors can be reduced if circulating adrenaline is reduced, and this can be achieved by the administration of butorphanol plus oxygen insufflation. Furthermore, to assist with reducing the risks associated with rhinoceros immobilisation, tremor intensity could be used as a clinical indicator of respiratory and metabolic compromise.

  11. The GABA Hypothesis in Essential Tremor: Lights and Shadows.

    Science.gov (United States)

    Gironell, Alexandre

    2014-01-01

    The gamma-aminobutyric acid (GABA) hypothesis in essential tremor (ET) implies a disturbance of the GABAergic system, especially involving the cerebellum. This review examines the evidence of the GABA hypothesis. The review is based on published data about GABA dysfunction in ET, taking into account studies on cerebrospinal fluid, pathology, electrophysiology, genetics, neuroimaging, experimental animal models, and human drug therapies. Findings from several studies support the GABA hypothesis in ET. The hypothesis follows four steps: 1) cerebellar neurodegeneration with Purkinje cell loss; 2) a decrease in GABA system activity in deep cerebellar neurons; 3) disinhibition in output deep cerebellar neurons with pacemaker activity; and 4) an increase in rhythmic activity of the thalamus and thalamo-cortical circuit, contributing to the generation of tremor. Doubts have been cast on this hypothesis, however, by the fact that it is based on relatively few works, controversial post-mortem findings, and negative genetic studies on the GABA system. Furthermore, GABAergic drug efficacy is low and some GABAergic drugs do not have antitremoric efficacy. The GABA hypothesis continues to be the most robust pathophysiological hypothesis to explain ET. There is light in all GABA hypothesis steps, but a number of shadows cannot be overlooked. We need more studies to clarify the neurodegenerative nature of the disease, to confirm the decrease of GABA activity in the cerebellum, and to test more therapies that enhance the GABA transmission specifically in the cerebellum area.

  12. Linking Essential Tremor to the Cerebellum: Physiological Evidence.

    Science.gov (United States)

    Filip, Pavel; Lungu, Ovidiu V; Manto, Mario-Ubaldo; Bareš, Martin

    2016-12-01

    Essential tremor (ET), clinically characterized by postural and kinetic tremors, predominantly in the upper extremities, originates from pathological activity in the dynamic oscillatory network comprising the majority of nodes in the central motor network. Evidence indicates dysfunction in the thalamus, the olivocerebellar loops, and intermittent cortical engagement. Pathology of the cerebellum, a structure with architecture intrinsically predisposed to oscillatory activity, has also been implicated in ET as shown by clinical, neuroimaging, and pathological studies. Despite electrophysiological studies assessing cerebellar impairment in ET being scarce, their impact is tangible, as summarized in this review. The electromyography-magnetoencephalography combination provided the first direct evidence of pathological alteration in cortico-subcortical communication, with a significant emphasis on the cerebellum. Furthermore, complex electromyography studies showed disruptions in the timing of agonist and antagonist muscle activation, a process generally attributed to the cerebellum. Evidence pointing to cerebellar engagement in ET has also been found in electrooculography measurements, cerebellar repetitive transcranial magnetic stimulation studies, and, indirectly, in complex analyses of the activity of the ventral intermediate thalamic nucleus (an area primarily receiving inputs from the cerebellum), which is also used in the advanced treatment of ET. In summary, further progress in therapy will require comprehensive electrophysiological and physiological analyses to elucidate the precise mechanisms leading to disease symptoms. The cerebellum, as a major node of this dynamic oscillatory network, requires further study to aid this endeavor.

  13. Eye movements between saccades: Measuring ocular drift and tremor.

    Science.gov (United States)

    Ko, Hee-Kyoung; Snodderly, D Max; Poletti, Martina

    2016-05-01

    Intersaccadic periods of fixation are characterized by incessant retinal motion due to small eye movements. While these movements are often disregarded as noise, the temporal modulations they introduce to retinal receptors are significant. However, analysis of these input modulations is challenging because the intersaccadic eye motion is close to the resolution limits of most eyetrackers, including widespread pupil-based video systems. Here, we analyzed in depth the limits of two high-precision eyetrackers, the Dual-Purkinje Image and the scleral search coil, and compared the intersaccadic eye movements of humans to those of a non-human primate. By means of a model eye we determined that the resolution of both techniques is sufficient to reliably measure intersaccadic ocular activity up to approximately 80Hz. Our results show that the characteristics of ocular drift are remarkably similar in the two species; a clear deviation from a scale-invariant spectrum occurs in the range between 50 and 100Hz, generally attributed to ocular tremor, leading to intersaccadic retinal speeds as high as 1.5deg/s. The amplitude of this deviation differs on the two axes of motion. In addition to our experimental observations, we suggest basic guidelines to evaluate the performance of eyetrackers and to optimize experimental conditions for the measurement of ocular drift and tremor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Landslides at Beachy Head, Sussex

    OpenAIRE

    Pennington, Catherine

    2007-01-01

    Beachy Head (Figures 1 and 2) is a famous natural and historic site and tourist attraction on the south coast. The cliff top area is part of the Downland Country Park managed by Eastbourne District Council. The section of cliff surveyed at Beachy Head is situated to the east of the modern lighthouse. The survey spans a 400 m south-facing stretch of beach with a cliff height of between 120 and 160 m. Cliffs and lighthouse at Beachy Head As part of a programme of work monitoring coast...

  15. An Unwilling Partnership With the Great Society Part I: Head Start and the Beginning of Change in the White Medical Community.

    Science.gov (United States)

    deShazo, Richard D; Minor, Wilson F Bill; Smith, Robert; Skipworth, Leigh Baldwin

    2016-07-01

    By 1965, the policies and programs of Lyndon B. Johnson's Great Society brought optimism to black physicians and a new wave of resistance against black civil rights advocates in the American South. The largest of the first Head Start programs, Child Development Group of Mississippi (CDGM), had its roots in Freedom Summer 1964 and the Medical Committee for Human Rights. Like other proposed programs with strong medical components, CDGM was caught in a legislative Bermuda triangle created by the powerful Mississippi congressional delegation to maintain white supremacy and plantation economics. Physician-led investigations exposed the extraordinary level of poor health among Mississippi's black children, supported Head Start as a remedy, and awakened the white medical establishment to health disparities of the Jim Crow period. It was also the beginning of positive change in the previously silent white medical community in the South and their support of civil justice in health. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  16. Evaluation of precipitates used in strainer head loss testing: Part III. Long-term aluminum hydroxide precipitation tests in borated water

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, Chi Bum, E-mail: bahn@anl.go [Argonne National Laboratory, Lemont, IL 60439 (United States); Kasza, Ken E.; Shack, William J.; Natesan, Ken [Argonne National Laboratory, Lemont, IL 60439 (United States); Klein, Paul [United States Nuclear Regulatory Commission, Rockville, MD 20852 (United States)

    2011-05-15

    Research highlights: Aluminum hydroxide precipitation boundary is similar to that for amorphous phase. Various precipitation tests are combined into one map in temperature-'pH + p[Al]{sub T}'. Flocculation tendency of precipitates depend on pH and total Al concentration. DLVO theory explains qualitatively the dependency of flocculation tendency on pH. - Abstract: Long-term aluminum (Al) hydroxide precipitation tests were conducted in slightly alkaline solutions containing 2500 ppm boron. The solution temperature was cycled to obtain a temperature history more representative of emergency core cooling system temperatures after a loss-of-coolant accident. The observed Al precipitation boundary was close to predicted results for amorphous precipitates, which are higher than the solubility expected for crystalline forms. Bench-scale and loop head loss test results under various conditions were successfully combined into single map in a temperature - 'pH + p[Al]{sub T}' domain, which yielded two bounding lines for Al hydroxide solubility in borated alkaline water that depend on whether or not loop head loss tests with Al alloy coupons are included. Precipitates were observed to form either as fine, cloudy suspensions, which showed very little tendency to settle, or as flocculated precipitates. The flocculation tendency of the precipitates can be qualitatively explained by a colloid stability theory or a phase diagram for protein solutions.

  17. Evaluation of precipitates used in strainer head loss testing : Part III. Long-term aluminum hydroxide precipitation tests in borated water.

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, C. B.; Kasza, K. E.; Shack, W. J.; Natesan, K.; Klein, P. (Nuclear Engineering Division); (USNRC)

    2011-05-01

    Long-term aluminum (Al) hydroxide precipitation tests were conducted in slightly alkaline solutions containing 2500 ppm boron. The solution temperature was cycled to obtain a temperature history more representative of emergency core cooling system temperatures after a loss-of-coolant accident. The observed Al precipitation boundary was close to predicted results for amorphous precipitates, which are higher than the solubility expected for crystalline forms. Bench-scale and loop head loss test results under various conditions were successfully combined into single map in a temperature - 'pH + p[Al]{sub T}' domain, which yielded two bounding lines for Al hydroxide solubility in borated alkaline water that depend on whether or not loop head loss tests with Al alloy coupons are included. Precipitates were observed to form either as fine, cloudy suspensions, which showed very little tendency to settle, or as flocculated precipitates. The flocculation tendency of the precipitates can be qualitatively explained by a colloid stability theory or a phase diagram for protein solutions.

  18. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  19. Dynamic investigations of various civil engineering structures due to ambient and mining tremors

    Directory of Open Access Journals (Sweden)

    Kuzniar Krystyna

    2015-01-01

    Full Text Available The first part of the study deals with evaluation of dynamic characteristics of selected typical industrial facilities, such as the extraction steel tower, reinforced concrete tower skips. These structures are located in the coal mine area. The constructions of the test items are varied and complicated, which causes difficulties in the research in situ. In the investigation we used normal and emergency operation of lifting equipment, the effect of wind gusts and rhythmic man swaying. The second part of the study involves the determination of the dynamic characteristics of tailing dam. In this case mining tremors were used as the sources of vibration excitations. By using natural vibration excitation source it was possible to determine the lowest frequency of free vibration of the tailing dam. The third part of the paper focuses on the results of measurements of mine-induced ground vibrations and vibrations of residential buildings of various types. Typical one-family masonry houses as well as 5 and 12 storey reinforced prefabricated buildings were examined. The studies were conducted to determine the transmission of free-field vibrations to the building foundations. According to the significant differences between the simultaneously measured ground and building foundation vibrations, results of experimental tests obtained by means of response spectra are essential for the proper adoption of kinematic loads for dynamic models of these structures. The results of experimental studies were the basis for the verification of dynamic models of investigated structures.

  20. Long-term outcome of deep brain stimulation in fragile X-associated tremor/ataxia syndrome.

    Science.gov (United States)

    Weiss, Daniel; Mielke, Carina; Wächter, Tobias; Bender, Benjamin; Liscic, Rajka M; Scholten, Marlieke; Naros, Georgios; Plewnia, Christian; Gharabaghi, Alireza; Krüger, Rejko

    2015-03-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) presents as complex movement disorder including tremor and cerebellar ataxia. The efficacy and safety of deep brain stimulation of the nucleus ventralis intermedius of the thalamus in atypical tremor syndromes like FXTAS remains to be determined. Here, we report the long-term outcome of three male genetically confirmed FXTAS patients treated with bilateral neurostimulation of the nucleus ventralis intermedius for up to four years. All patients demonstrated sustained improvement of both tremor and ataxia - the latter included improvement of intention tremor and axial tremor. Kinematic gait analyses further demonstrated a regularization of the gait cycle. Initial improvements of hand functional disability were not sustained and reached the preoperative level of impairment within one to two years from surgery. Our data on patients with a genetic cause of tremor show favorable outcome and may contribute to improved patient stratification for neurostimulation therapy in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Deep brain stimulation or thalamotomy in fragile X-associated tremor/ataxia syndrome? Case report.

    Science.gov (United States)

    Tamás, Gertrúd; Kovács, Norbert; Varga, Noémi Ágnes; Barsi, Péter; Erőss, Loránd; Molnár, Mária Judit; Balás, István

    2016-01-01

    We present the case of a 66-year-old man who has been treated for essential tremor since the age of 58. He developed mild cerebellar gait ataxia seven years after tremor onset. Moderate, global brain atrophy was identified on MRI scans. At the age of 68, only temporary tremor relief could be achieved by bilateral deep brain stimulation of the ventral intermedius nucleus of the thalamus. Bilateral stimulation of the subthalamic nucleus also resulted only in transient improvement. In the meantime, progressive gait ataxia and tetraataxia developed accompanied by other cerebellar symptoms, such as nystagmus and scanning speech. These correlated with progressive development of bilateral symmetric hyperintensity of the middle cerebellar peduncles on T2 weighted MRI scans. Genetic testing revealed premutation of the FMR1 gene, establishing the diagnosis of fragile X-associated tremor/ataxia syndrome. Although this is a rare disorder, it should be taken into consideration during preoperative evaluation of essential tremor. Postural tremor ceased two years later after thalamotomy on the left side, while kinetic tremor of the right hand also improved. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  2. Atypical Porcine Pestivirus: A Possible Cause of Congenital Tremor Type A‐II in Newborn Piglets

    Directory of Open Access Journals (Sweden)

    Ad de Groof

    2016-10-01

    Full Text Available Congenital tremor type A‐II in piglets has been regarded as a transmissible disease since the 1970s, possibly caused by a very recently‐described virus: atypical porcine pestivirus (APPV. Here, we describe several strains of APPV in piglets with clinical signs of congenital tremor (10 of 10 farms tested. Piglets on a farm with no history of congenital tremor were PCR‐negative for the virus. To demonstrate a causal relationship between APPV and disease, three gilts were inoculated via intramuscular injection at day 32 of pregnancy. In two of the three litters, vertical transmission of the virus occurred. Clinical signs of congenital tremor were observed in APPV‐infected newborns, yet also two asymptomatic carriers were among the offspring. Piglets of one litter were PCR‐negative for the virus, and these piglets were all without congenital tremors. Long‐term follow up of farm piglets born with congenital tremors showed that the initially high viremia in serum declines at five months of age, but shedding of the virus in feces continues, which explains why the virus remains present at affected farms and causes new outbreaks. We conclude that trans‐placental transmission of APPV and subsequent infection of the fetuses is a very likely cause of congenital tremor type A‐II in piglets.

  3. Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor

    Science.gov (United States)

    2013-01-01

    Background Recent studies suggest that surface muscular functional electrical stimulation (FES) might suppress neurological upper limb tremor. We assessed its effects on upper limb physiological tremor, which is mainly driven by mechanical-reflex oscillations. We investigated the interaction between FES and augmented visual feedback, since (a) most daily activities are performed using visual cues, and (b) augmented visual feedback exacerbates upper limb tremor. Methods 10 healthy subjects (23.4 ± 7.7 years) performed 2 postural tasks with combinations of FES (4 sites; frequency of stimulation: 30 Hz; pulse width: 300 microsec; range of current delivered 10–34 mAmp) and augmented visual feedback. Results Spectral analysis of tremor showed a decrease of power spectral density to 62.18% (p = 0.01), of the integral in the 8-12 Hz frequency band to 57.67% (p = 0.003), and of tremor root mean square (RMS) to 57.16% (p = 0.002) during FES, without any changes in tremor frequency. Augmented visual feedback blocked the beneficial effect of FES, as confirmed by power spectral analysis (p = 0.01). We found a statistically significant interaction between augmented visual feedback and electrical stimulation (p = 0.039). Conclusions Augmented visual feedback antagonizes the effects of FES on physiological tremor. The absence of changes of peak frequency argues against an effect of FES on mechanical properties of the upper limb. PMID:24063436

  4. Estimation of pathological tremor from recorded signals based on adaptive sliding fast Fourier transform

    Directory of Open Access Journals (Sweden)

    Shengxin Wang

    2016-06-01

    Full Text Available Pathological tremor is an approximately rhythmic movement and considerably affects patients’ daily living activities. Biomechanical loading and functional electrical stimulation are proposed as potential alternatives for canceling the pathological tremor. However, the performance of suppression methods is associated with the separation of tremor from the recorded signals. In this literature, an algorithm incorporating a fast Fourier transform augmented with a sliding convolution window, an interpolation procedure, and a damping module of the frequency is presented to isolate tremulous components from the measured signals and estimate the instantaneous tremor frequency. Meanwhile, a mechanism platform is designed to provide the simulation tremor signals with different degrees of voluntary movements. The performance of the proposed algorithm and existing procedures is compared with simulated signals and experimental signals collected from patients. The results demonstrate that the proposed solution could detect the unknown dominant frequency and distinguish the tremor components with higher accuracy. Therefore, this algorithm is useful for actively compensating tremor by functional electrical stimulation without affecting the voluntary movement.

  5. Multiple coincident eruptive seismic tremor sources during the 2014-2015 eruption at Holuhraun, Iceland

    Science.gov (United States)

    Eibl, Eva P. S.; Bean, Christopher J.; Jónsdóttir, Ingibjörg; Höskuldsson, Armann; Thordarson, Thorvaldur; Coppola, Diego; Witt, Tanja; Walter, Thomas R.

    2017-04-01

    We analyze eruptive tremor during one of the largest effusive eruptions in historical times in Iceland (2014/2015 Holuhraun eruption). Seismic array recordings are compared with effusion rates deduced from Moderate Resolution Imaging Spectroradiometer recordings and ground video monitoring data and lead to the identification of three coexisting eruptive tremor sources. This contrasts other tremor studies that generally link eruptive tremor to only one source usually associated with the vent. The three sources are (i) a source that is stable in back azimuth and shows bursts with ramp-like decrease in amplitude at the beginning of the eruption: we link it to a process below the open vents where the bursts correlate with the opening of new vents and temporary increases in the lava fountaining height; (ii) a source moving by a few degrees per month while the tremor amplitude suddenly increases and decreases: back azimuth and slowness correlate with the growing margins of the lava flow field, whilst new contact with a river led to fast increases of the tremor amplitude; and (iii) a source moving by up to 25° southward in 4 days that cannot be related to any observed surface activity and might be linked to intrusions. We therefore suggest that eruptive tremor amplitudes/energies are used with caution when estimating eruptive volumes, effusion rates, or the eruption explosivity as multiple sources can coexist during the eruption phase. Our results suggest that arrays can monitor both the growth of a lava flow field and the activity in the vents.

  6. Effect of stretching and proprioceptive loading in hand function among patients with cerebellar tremor

    Directory of Open Access Journals (Sweden)

    Hariharasudhan Ravichandran

    2016-01-01

    Full Text Available Background and Objective: Tremor, the most common form of abnormal involuntary movement, affects the performance of activities of daily living. Evidence on effective form of physiotherapy techniques which can help manage intentional tremor and improve hand function among cerebellar dysfunction patients in inconclusive. Hence, this study aims to establish the effectiveness of stretching and proprioceptive loading among cerebellar patients with intentional tremors. The objective of this study is to compare the efficacy of stretching and proprioceptive loading among patients with cerebellar intention tremor. Materials and Methods: A total of thirty patients with intention tremor due to cerebellar lesion were recruited for this study. They were randomized into two groups, Group I received stretching exercise and Group II received proprioceptive loading exercise. Pre- and post-test outcome measures were taken at the end of duration of 3 weeks intervention. Outcome measures were Fahn's tremor rating scale and nine hole peg test. Results: Statistical analyses were done by McNemar test, Wilcoxon's signed rank test, and Mann–Whitney test. Post-test scores of both groups were compared and found that Group II treated with proprioceptive loading exercise had higher significant result than the group treated with strengthening exercise program. Conclusion: Proprioceptive loading exercise has demonstrated signifi cant effect on reducing cerebellar tremor and improving muscle coordination in reaching activities.

  7. Occupational mercury exposure in association with prevalence of multiple sclerosis and tremor among US dentists.

    Science.gov (United States)

    Anglen, Julia; Gruninger, Stephen E; Chou, Hwai-Nan; Weuve, Jennifer; Turyk, Mary Ellen; Freels, Sally; Stayner, Leslie Thomas

    2015-09-01

    The effects of chronic occupational exposure to elemental mercury (Hg(0)) are largely unknown. The objective was to evaluate the association of occupational Hg(0) exposure with multiple sclerosis (MS) and tremor. The study included 13,906 dentists who attended the American Dental Association's annual meeting over 24 years (1986-2007 and 2011-2012). Participants reported MS and tremor and provided urine specimens for Hg(0) analysis. The authors estimated mean Hg(0) exposures over time and used logistic regression to estimate the associations of 3 Hg(0) exposure measures with MS or tremor. Among participants, 0.18% reported MS and 1.24% reported tremor. Hg(0) exposure was not associated with MS (odds ratio [OR] per 191 micrograms per liter in cumulative Hg(0) exposure, 0.85; 95% confidence interval [CI], 0.39-1.85). Increased prevalent risk of tremor was found with exposure to both urinary Hg(0) exposure (OR, 1.10 [95% CI, 1.00-1.22]) and cumulative Hg(0) exposure among younger dentists (tremor. Studies with more sophisticated outcome and exposure measures, and including more retired dentists, would provide critical information toward understanding the relation of Hg(0) exposures to MS and tremor risk. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

  8. Abnormal head oscillations in neuro-ophthalmology and neuro-otology

    Science.gov (United States)

    Shaikh, Aasef G.

    2016-01-01

    Purpose This paper describes the clinical phenomenology and contemporary pathophysiology of concurrent oscillations of the eyes and the head that are present in neurological conditions with diverse etiologies. Recent findings One classic example is spasmus nutans in which the eye oscillations are the primary pathology while head nodding is thought to be an operant conditional response that suppresses the eye oscillations to facilitate clear vision. The second example is a combination of head tremor and inadequate compensatory eye movements due to vestibular hypofunction leading to the illusion of pendular nystagmus – hence the condition is called pseudonystagmus. Cerebellar degeneration in ataxia-telangiectasia or synchronized spontaneous discharge from the inferior olive and cerebellum in the syndrome of ocular palatal tremor with dystonia are examples of eye and head oscillations due to the impairment in cerebellar outflow. Infantile nystagmus syndrome also presents with eye and head oscillations, but here the relationship between the two types of oscillations differs among patients and is still unclear. Summary The clinical features and putative pathophysiology of diverse disorders of the eyes and head that produce unwanted oscillations are reviewed and some analogies between eye and head oscillations are suggested. Key clinical pearls that are essential to separate these disorders at the bedside are also emphasized. PMID:26641814

  9. Space-Time Variations in Tidal Stress and Cascadia Tremor Amplitude

    Science.gov (United States)

    Klaus, A. J.; Creager, K. C.; Sweet, J.; Wech, A.

    2011-12-01

    We present a new analysis of the influence of tidal stresses on the amplitude of non-volcanic tremor in Washington State. Tremor counts (Thomas et al., 2009), tremor amplitude (Rubinstein et al., 2008), and strain (Hawthorne and Rubin, 2010) are modulated by tidal stresses in Cascadia as well as in California. However, tremor amplitudes have not yet been extensively studied in Cascadia. Furthermore, Hawthorne and Rubin's Cascadia-wide tidal stress model (2010) allows us to look at the tremor-tide relationship in more detail than ever before. The ability to look at the tidal modulation of tremor amplitude in space as well as time will increase our understanding of this phenomenon and may provide information about the frictional properties of the plate interface. We focus on the August 2010 episodic tremor and slip (ETS) event recorded by the Array of Arrays, a seismic experiment on the Olympic Peninsula. The instrument response is deconvolved, seismograms band-pass filtered at 1.5-5.5 Hz and envelopes are made in 5-minute windows. An inverse problem compensates for site corrections and source-receiver distances to produce, for any given time, a single amplitude measurement at the source. Source locations are determined using an envelope waveform cross-correlation method. Then, we compare the amplitudes, catalog of tremor locations, and the tidal stress at the desired location and time. Amplitudes during the August 2010 ETS event are clearly modulated by tidal stresses. Viewed in the frequency domain, there are clear peaks in the tremor amplitude spectrum at several tidal periods, most prominently the 12.4 and 24 hour periods. Comparison with Hawthorne and Rubin's tidal stress model shows that higher amplitudes are associated with positive shear stress in the downdip direction and, less strongly, with more compressional normal stress.

  10. Biomechanical Loading as an Alternative Treatment for Tremor: A Review of Two Approaches

    Directory of Open Access Journals (Sweden)

    Eduardo Rocon

    2011-08-01

    Full Text Available Background: Tremor is the most common movement disorder and strongly increases in incidence and prevalence with aging. Although not life threatening, upper-limb tremors hamper the independence of 65% of people suffering from them affected persons, greatly impacting their quality of life. Current treatments include pharmacotherapy and surgery (thalamotomy and deep brain stimulation. However, these options are not sufficient for approximately 25% of patients. Therefore, further research and new therapeutic options are required to effectively manage pathological tremor.Methods: This paper presents findings of two research projects in which two different wearable robots for tremor management were developed based on force loading and validated. The first consisted of a robotic exoskeleton that applied forces to tremulous limbs and consistently attenuated mild and severe tremors. The second was a neuroprosthesis based on transcutaneous neurostimulation. A total of 22 patients suffering from parkinsonian or essential tremor (ET of different severities were recruited for experimental validation, and both systems were evaluated using standard tasks employed for neurological examination. The inclusion criterion was a postural and/or kinetic pathological upper-limb tremor resistant to medication.Results: The results demonstrate that both approaches effectively suppressed tremor in most patients, although further research is required. The work presented here is based on clinical evidence from a small number of patients (n = 10 for robotic exoskeleton and n = 12 for the neuroprosthesis, but most had a positive response to the approaches. In summary, biomechanical loading is non-invasive and painless. It may be effective in patients who are insufficiently responsive (or have adverse reactions to drugs or in whom surgery is contraindicated.Discussion: This paper identifies and evaluates biomechanical loading approaches to tremor management and

  11. Tremor Reduction by Deep Brain Stimulation Is Associated With Gamma Power Suppression in Parkinson's Disease.

    Science.gov (United States)

    Beudel, Martijn; Little, Simon; Pogosyan, Alek; Ashkan, Keyoumars; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Bogdanovic, Marko; Cheeran, Binith; Green, Alexander L; Aziz, Tipu; Thevathasan, Wesley; Brown, Peter

    2015-07-01

    Rest tremor is a cardinal symptom of Parkinson's disease (PD), and is readily suppressed by deep brain stimulation (DBS) of the subthalamic nucleus (STN). The therapeutic effect of the latter on bradykinesia and rigidity has been associated with the suppression of exaggerated beta (13-30 Hz) band synchronization in the vicinity of the stimulating electrode, but there is no correlation between beta suppression and tremor amplitude. In the present study, we investigate whether tremor suppression is related to suppression of activities at other frequencies. We recorded hand tremor and contralateral local field potential (LFP) activity from DBS electrodes during stimulation of the STN in 15 hemispheres in 11 patients with PD. DBS was applied with increasing voltages starting at 0.5 V until tremor suppression was achieved or until 4.5 V was reached. Tremor was reduced to 48.9% ± 10.9% of that without DBS once stimulation reached 2.5-3 V (t14 = -4.667, p tremor frequencies and their harmonic (4-12 Hz), or over the beta band. Moreover, low gamma power correlated with tremor severity (mean r = 0.43 ± 0.14, p = 0.008) within subjects. This was not the case for LFP power in the other two bands. Our findings support a relationship between low gamma oscillations and PD tremor, and reinforce the principle that the subthalamic LFP is a rich signal that may contain information about the severity of multiple different Parkinsonian features. © 2015 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals, Inc. on behalf of International Neuromodulation Society.

  12. Cognitive and neuropsychiatric features of orthostatic tremor: A case-control comparison.

    Science.gov (United States)

    Benito-León, Julián; Louis, Elan D; Puertas-Martín, Verónica; Romero, Juan Pablo; Matarazzo, Michele; Molina-Arjona, José Antonio; Domínguez-González, Cristina; Sánchez-Ferro, Álvaro

    2016-02-15

    Evidence suggests that the cerebellum could play a role in the pathophysiology of orthostatic tremor. The link between orthostatic tremor and the cerebellum is of interest, especially in light of the role the cerebellum plays in cognition, and it raises the possibility that orthostatic tremor patients could have cognitive deficits consistent with cerebellar dysfunction. Our aim was to examine whether orthostatic tremor patients had cognitive deficits and distinct personality profiles when compared with matched controls. Sixteen consecutive orthostatic tremor patients (65.7 ± 13.3 years) and 32 healthy matched controls underwent a neuropsychological battery and the Personality Assessment Inventory. In linear regression models, the dependent variable was each one of the neuropsychological test scores or the Personality Assessment Inventory subscales and the independent variable was orthostatic tremor vs. Adjusted for age in years, sex, years of education, comorbidity index, current smoker, and depressive symptoms, diagnosis (orthostatic tremor vs. healthy control) was associated with poor performance on tests of executive function, visuospatial ability, verbal memory, visual memory, and language tests, and on a number of the Personality Assessment Inventory subscales (somatic concerns, anxiety related disorders, depression, and antisocial features). Older-onset OT (>60 years) patients had poorer scores on cognitive and personality testing compared with their younger-onset OT counterparts. Orthostatic tremor patients have deficits in specific aspects of neuropsychological functioning, particularly those thought to rely on the integrity of the prefrontal cortex, which suggests involvement of frontocerebellar circuits. Cognitive impairment and personality disturbances could be disease-associated nonmotor manifestations of orthostatic tremor. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Evaluation of the impact of water harvesting techniques on the evolution of piezometric head of Ain El Bidha groundwater in Kairouan at the Central part of Tunisia

    Science.gov (United States)

    Mechergui, M. Mohamed; Henda Saoudi, Mme

    2016-04-01

    This study aims to assess the impact of water harvesting constructed hydraulic structures (big and small dams, terraces, seuils for recharge…) on the evolution of piezometric head of Ain El Beidha groundwater table. The measurements of depth of water table, taken at the end of rain season and at the end of irrigation season, in many piezometers and monitoring wells, for a long period of observation before and after implementation of all the hydraulic structures, were used with the cumulative rain to the highest water table to diagnostic the effect of natural recharge and constructed hydraulic structures. According to the analysis of curves illustrating the evolution of piezometric head and rainfall over time, it was shown that despite the fact that the same amount of rain fall on the total area in the limits of Ain El Beidha groundwater table, the piezometers respond differently. This is because there are many sources of recharge and many factors affecting the recharge. First of all, the aquifer is divided in four compartments (the calcareous formation of Djebel El Houyareb, the plio-quaternary formation, the Miocene formation: Baglia and Saouaf). All those respond differently to the recharge by their capacity of infiltration and their hydrodynamic characteristics. The recharge of the groundwater table was increased by the implementation of small soil and water conservation structures, artificial lakes, El Haouareb Dam, run off in the natural Oued bads and seuils for recharge installed in the bads of oueds. The different piezometric drown maps were used to determine the flow direction and hydraulic gradient in order to identify the recharge areas, while tracking maps for three equal piezometric heads 210 m 300 m and 370 m established over different years made it possible to assess the impact of hydraulic structures, namely the effect of SWC and Ben Zitoun Lake. To illustrate the impact of El Houareb dam on the groundwater, the piezometric maps and local values

  14. Current Assessment of Integrated Content of Long-Lived Radionuclides in Soils of the Head Part of the East Ural Radioactive Trace - Current Assessment of Integrated Stocks of Long-Lived Radionuclides in Soils of the Head Part of the East-Ural Radioactive Trace

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, Konstantin L. [Institute of Industrial Ecology UB RAS, 620990 Kovalevskoy St., 20, Ekaterinburg (Russian Federation); Molchanova, Inna V.; Mikhailovskaya, Lyudmila N.; Pozolotina, Vera N.; Antonova, Elena V. [Institute of Plant and Animal Ecology UB RAS, 8 Marta St., 202, 620144 Ekaterinburg (Russian Federation)

    2014-07-01

    The East Ural Radioactive Trace is a result of the accident at the Production Association Mayak in 1957(the Kyshtym accident). The {sup 90}Sr was the main contaminant among long-lived radionuclides. Most of it was concentrated in the zone closest to the accident epicentre to the north-west (a narrow sector of about 15 deg., 35 km long). Later, in 1967, the EURT area was contaminated again with air-borne radioactive sediments from Lake Karachay, which had been used by the PA Mayak for storage of liquid radioactive waste. At this case the primary contaminant was {sup 137}Cs most of which was spread within 60 deg. sector oriented in the same direction (Aarkrog et al., 1997; Romanov et al., 1990). Our earlier radioecological studies included the assessment of integrated quantities of {sup 90}Sr, {sup 137}Cs, and {sup 239,240}Pu within the central axis of the trace (Pozolotina et al., 2008; Molchanova et al., 2009). The aim of this investigation was the current assessment of integrated stocks of {sup 90}Sr, {sup 137}Cs, and {sup 239,240}Pu in soils of the head part of the EURT along the central axis and the adjacent areas, to map the contamination data of the studied area using established geostatistical models by ArcGIS 9.3 (ESRI, USA). An inventory of the existing data (38 sampling locations) was performed earlier (Molchanova et al., 2009). Currently the database has information on 102 soil profile cuts. Taking into account the presence of global trends and anisotropy in the source data, ordinary kriging interpolation method was used. Geostatistical data analysis was performed for the determination of the basic parameters of spatial dependencies and the integral assessment of long-lived radionuclides in soils of the central, east peripheral, and west one parts of the trace. This analysis employed simplified geometric models (sector- and rectangle-shaped areas). The Monte Carlo technique was used for quantitatively assesses the uncertainty of the integrated stocks to

  15. The changing profile of infantile tremor syndrome in hilly terrain of India

    Directory of Open Access Journals (Sweden)

    Deeksha A Singla

    2015-01-01

    Full Text Available Background: Infantile tremor syndrome (ITS is characterized by anemia, skin pigmentation, tremors, physical, and mental regression without a defined etiopathogenesis and low incidence. Materials and Methods: We have studied 9 patients over 1 year for the changing clinical and laboratory variables of patients with ITS. Neuroregression and anemia were presented in all followed by tremors in 5 and hypotonia in 2. Result: Sepsis screen was positive in 6 and urine cultures in 2. Antibiotics were required in 6. ITS with changing parameters still significantly contributes to healthcare burden. Conclusion: It is important to screen for urinary infection and septicemia to avoid antibiotic abuse.

  16. Spectrogram analysis of selected tremor signals using short-time Fourier transform and continuous wavelet transform

    Directory of Open Access Journals (Sweden)

    D. Seidl

    1999-06-01

    Full Text Available Among a variety of spectrogram methods Short-Time Fourier Transform (STFT and Continuous Wavelet Transform (CWT were selected to analyse transients in non-stationary tremor signals. Depending on the properties of the tremor signal a more suitable representation of the signal is gained by CWT. Three selected broadband tremor signals from the volcanos Mt. Stromboli, Mt. Semeru and Mt. Pinatubo were analyzed using both methods. The CWT can also be used to extend the definition of coherency into a time-varying coherency spectrogram. An example is given using array data from the volcano Mt. Stromboli.

  17. Acquired progressive ataxia and palatal tremor: importance of MRI evidence of hemosiderin deposition and vascular malformations.

    Science.gov (United States)

    Kumar, Neeraj; Eggers, Scott D Z; Milone, Margherita; Keegan, B Mark

    2011-08-01

    Oculopalatal tremor is frequently accompanied by progressive ataxia. In symptomatic oculopalatal tremor the ataxia frequently is delayed in onset. Progressive ataxia is a defining clinical feature of superficial siderosis. We report 5 cases with palatal tremor and ataxia. Four cases had evidence of intraparenchymal hemosiderin deposition on T2-gradient-echo imaging. Three cases had a brainstem vascular malformation. In two cases the hemosiderin deposition was likely due to prior trauma. The significance of these associations and possible similarities between ataxia related to superficial siderosis and ataxia and intraparenchymal hemosiderin is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Combined thalamic and subthalamic deep brain stimulation for tremor-dominant Parkinson's disease.

    Science.gov (United States)

    Oertel, Markus F; Schüpbach, W Michael M; Ghika, Joseph-André; Stieglitz, Lennart H; Fiechter, Michael; Kaelin-Lang, Alain; Raabe, Andreas; Pollo, Claudio

    2017-02-01

    Deep brain stimulation (DBS) in the thalamic ventral intermediate (Vim) or the subthalamic nucleus (STN) reportedly improves medication-refractory Parkinson's disease (PD) tremor. However, little is known about the potential synergic effects of combined Vim and STN DBS. We describe a 79-year-old man with medication-refractory tremor-dominant PD. Bilateral Vim DBS electrode implantation produced insufficient improvement. Therefore, the patient underwent additional unilateral left-sided STN DBS. Whereas Vim or STN stimulation alone led to partial improvement, persisting tremor resolution occurred after simultaneous stimulation. The combination of both targets may have a synergic effect and is an alternative option in suitable cases.

  19. Estudo retrospetivo sobre tremor epizoótico em Portugal

    OpenAIRE

    Barreto, Ana Catarina da Silva

    2014-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária O tremor epizoótico (TE) é uma encefalopatia espongiforme transmissível (EET) que ocorre naturalmente em ovinos, caprinos e muflões. É uma doença conhecida há mais de 250 anos. Caracteriza-se pela acumulação da isoforma patológica- proteína priónica resistente (PrPres ou PrPsc) de uma proteína fisiológica do hospedeiro- proteína priónica celular (PrPc) no sistema nervoso central, conduzindo à progressiva neurodegeneração e morte. O ...

  20. Public Knowledge and Attitude towards Essential Tremor: A Questionnaire Survey

    Directory of Open Access Journals (Sweden)

    Sherif eShalaby

    2016-04-01

    Full Text Available Background: Public awareness of and attitude towards disease is an important issue for patients. Public awareness of essential tremor (ET has never been studied.Methods: We administered a ten-minute, 31-item questionnaire to 250 consecutive enrollees. These included three samples carefully chosen to have a potential range of awareness of ET: 100 individuals ascertained from a vascular disease clinic, 100 individuals from a general neurology clinic, and 50 Parkinson’s disease (PD patients. Results: Leaving aside PD patients, only 10-15% of enrollees had ever heard of or read about ET. Even among PD patients, only 32.7% had ever heard of or read about ET. After providing enrollees with three synonymous terms for ET (‘benign tremor’, ‘kinetic tremor’, ‘familial tremor’, approximately 40% of non-PD enrollees and 51.0% with PD had ever heard or read about the condition. Even among participants who had heard of ET, approximately 10% did not know what the main symptom was, 1/3 were either unsure or thought ET was the same disease as PD, 1/4 thought that ET was the same condition as frailty- or aging-associated tremor, 2/3 attributed it to odd causes (e.g., trauma or alcohol abuse, only 1/3 knew of the existence of therapeutic brain surgery, fewer than 1/2 knew that children could have ET and 3/4 did not know of a celebrity or historical figure with ET. Hence, lack of knowledge and misconceptions were common.Conclusions: Public knowledge of the existence and features of ET is overall poor. Greater awareness is important for the ET community.

  1. Treatment of essential tremor: Are there issues we are overlooking?

    Directory of Open Access Journals (Sweden)

    Elan D Louis

    2012-01-01

    Full Text Available Background: Essential tremor (ET is one of the most common neurological diseases. Although a large number of medications have been tested, there are only two first-line medications, primidone and propranolol, which is a situation that has not changed in approximately 30 years. Several recent reviews have summarized the current pharmacotherapeutic options for ET and the approach to the management of ET patients. Yet there remain a number of important issues, both scientific and clinical, that have not been broached in the literature and that have therapeutic implications. Objectives: To introduce several clinical and scientific issues that have not formally entered the published literature on the treatment of ET. Methods: In September 2011, materials for this article were gathered during a literature search of PubMed using the following terms: essential tremor, clinical, clinical trial, treatment, medications, therapeutics. English-language articles were selected for further review.Results: The paper focuses on several topics that have received scant or no discussion in the published literature on ET therapeutics. These topics are as follows: the nature of the underlying disease pathophysiology, the presence of pathological heterogeneity, the complexity of cellular and neurochemical changes which may be underlying this disorder, the presence of clinical heterogeneity, the selection of treatment endpoints, the effects of diagnostic uncertainty, the presence of cognitive and psychiatric features in ET, the identification of possible modifiable risk factors and the absence of any neuroprotective therapies. Conclusions: The author has identified several topics that have received scant or no discussion in the published literature on ET therapeutics. Further discussion of the issues raised here may lead to improvements in clinical trial methodologies as well as facilitate the development of fresh approaches to pharmacotherapy.

  2. A 15 year catalog of more than 1 million low-frequency earthquakes: Tracking tremor and slip along the deep San Andreas Fault

    Science.gov (United States)

    Shelly, David R.

    2017-05-01

    Low-frequency earthquakes (LFEs) are small, rapidly recurring slip events that occur on the deep extensions of some major faults. Their collective activation is often observed as a semicontinuous signal known as tectonic (or nonvolcanic) tremor. This manuscript presents a catalog of more than 1 million LFEs detected along the central San Andreas Fault from 2001 to 2016. These events have been detected via a multichannel matched-filter search, cross-correlating waveform templates representing 88 different LFE families with continuous seismic data. Together, these source locations span nearly 150 km along the central San Andreas Fault, ranging in depth from 16 to 30 km. This accumulating catalog has been the source for numerous studies examining the behavior of these LFE sources and the inferred slip behavior of the deep fault. The relatively high temporal and spatial resolutions of the catalog have provided new insights into properties such as tremor migration, recurrence, and triggering by static and dynamic stress perturbations. Collectively, these characteristics are inferred to reflect a very weak fault likely under near-lithostatic fluid pressure, yet the physical processes controlling the stuttering rupture observed as tremor and LFE signals remain poorly understood. This paper aims to document the LFE catalog assembly process and associated caveats, while also updating earlier observations and inferred physical constraints. The catalog itself accompanies this manuscript as part of the electronic supplement, with the goal of providing a useful resource for continued future investigations.

  3. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... contraception], Safety, Self-harm) interview is a feasible way of exploring health risk behaviors and resilience. OBJECTIVE: The purpose of this study was to evaluate how often HEADS topics were addressed according to young patients and staff in pediatric and adult outpatient clinics. METHODS: We conducted...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...

  4. Successful treatment of cerebellar ataxia and tremor in multiple sclerosis with topiramate: a case report.

    Science.gov (United States)

    Schroeder, Alexandra; Linker, Ralf A; Lukas, Carsten; Kraus, Peter H; Gold, Ralf

    2010-01-01

    We describe the clinical efficacy of topiramate for treatment of cerebellar dysfunction in a 33-year-old female patient with relapsing remitting multiple sclerosis. The patient presented severe ataxia and tremor precluding many activities of daily life. Topiramate was administered as a monotherapy and slowly tapered in to 150 mg daily without negative side effects. Treatment was well tolerated and led to a marked and lasting improvement of tremor as well as ataxia during an observation period of 2 years. Upon transient withdrawal of topiramate, ataxia and tremor worsened but were again improved after re-dosing of the drug. Multiple sclerosis immunotherapy was not changed in this period. In conclusion, topiramate may be a new therapeutic option to treat cerebellar tremor and ataxia in patients with multiple sclerosis.

  5. Effect of beta-adrenergic receptor antagonists on nicotine-induced tail-tremor in rats.

    Science.gov (United States)

    Suemaru, K; Gomita, Y; Furuno, K; Araki, Y

    1993-09-01

    The effects of various beta-adrenergic receptor antagonists on nicotine-induced tail-tremor were investigated in rats. Atenolol (5 and 10 mg/kg, IP), arotinolol (5 and 10 mg/kg, IP), and carteolol (5 and 10 mg/kg, IP), hydrophilic beta-adrenergic receptor antagonists, did not affect the tail-tremor induced by nicotine given at a dose of 0.5 mg/kg SC. However, propranolol (5-20 mg/kg, IP) and pindolol (5-20 mg/kg, IP), nonselective and lipophilic beta-adrenergic receptor antagonists, did suppress the tail-tremor dose dependently. In contrast, metoprolol (5-20 mg/kg, IP), lipophilic and beta 1-selective adrenergic receptor antagonists, did not show such an effect. These results suggest that nicotine-induced tail-tremors may be mediated through central beta 2-adrenergic receptors as an appearance and developmental mechanism.

  6. Precise tremor source locations and amplitude variations along the lower-crustal central San Andreas Fault

    Science.gov (United States)

    Shelly, David R.; Hardebeck, Jeanne L.

    2010-01-01

    We precisely locate 88 tremor families along the central San Andreas Fault using a 3D velocity model and numerous P and S wave arrival times estimated from seismogram stacks of up to 400 events per tremor family. Maximum tremor amplitudes vary along the fault by at least a factor of 7, with by far the strongest sources along a 25 km section of the fault southeast of Parkfield. We also identify many weaker tremor families, which have largely escaped prior detection. Together, these sources extend 150 km along the fault, beneath creeping, transitional, and locked sections of the upper crustal fault. Depths are mostly between 18 and 28 km, in the lower crust. Epicenters are concentrated within 3 km of the surface trace, implying a nearly vertical fault. A prominent gap in detectible activity is located directly beneath the region of maximum slip in the 2004 magnitude 6.0 Parkfield earthquake.

  7. Distinguishing essential tremor from Parkinson’s disease: bedside tests and laboratory evaluations

    Science.gov (United States)

    Thenganatt, Mary Ann; Louis, Elan D

    2012-01-01

    Distinguishing essential tremor from Parkinson’s disease can be challenging, both in the early stages of these diseases and as these diseases progress. Various tremor types (rest, postural, kinetic and intention) may be seen in both essential tremor and Parkinson’s disease. Furthermore, with time, the two diseases may coexist within a single patient. Detailed clinical examination with attention to specific features of tremor (frequency, amplitude, pattern and distribution) and associated neurological findings may help distinguish patients with the two diseases. Laboratory testing may provide information that further aids in differentiating the two diseases. These tests include accelerometry and surface electromyography, spiral analysis, dopamine transporter imaging, olfactory testing and, eventually, postmortem histopathology. These tests have limitations and their diagnostic utility requires additional study. PMID:22650171

  8. Decreased cortical inhibition and yet cerebellar pathology in 'familial cortical myoclonic tremor with epilepsy'

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; van der Salm, Sandra M. A.; Bour, Lo J.; Edwards, Mark J.; Brown, Peter; Aronica, Eleonora; Rozemuller-Kwakkel, Johanna M.; Koehler, Peter J.; Koelman, Johannes H. T. M.; Rothwell, John C.; Tijssen, Marina A. J.

    2007-01-01

    Cortical hyperexcitability is a feature of "familial cortical myoclonic tremor with epilepsy" (FCMTE). However, neuropathological investigations in a single FCMTE patient showed isolated cerebellar pathology. Pathological investigations in a second FCMTE patient, reported here, confirmed cerebellar

  9. Levetiracetam in primary orthostatic tremor: a double-blind placebo-controlled crossover study.

    Science.gov (United States)

    Hellriegel, Helge; Raethjen, Jan; Deuschl, G; Volkmann, Jens

    2011-11-01

    In a double-blind crossover study we evaluated the antitremor effect of a 4-week treatment with either escalating dosages of levetiracetam or placebo in orthostatic tremor. Twelve patients with orthostatic tremor participated in the study. Primary end point was improvement in stance duration. Secondary end points were total track length of the sway path and tremor total power. The patients' impression of impairment was assessed by a visual analog scale and quality of life by the SF-36. We found no significant effect of dosage or treatment on stance duration (P = .175), total track length (P = .690), total power (P = .280), or visual analog scale (P =.735). Neither was SF-36 differentially changed by levetiracetam or placebo (SF-36, Physical Component Summary: P = .079; SF-36, Mental Component Summary: P = .073). Side effects like dizziness, fatigue, or nausea were only mild to moderate. Levetiracetam is ineffective in the treatment of orthostatic tremor. Copyright © 2011 Movement Disorder Society.

  10. Detailed Tremor Migration Styles in Guerrero, Mexico Imaged with Cross-station Cross-correlations

    Science.gov (United States)

    Peng, Y.; Rubin, A. M.

    2015-12-01

    Tremor occurred downdip of the area that slipped the most during the 2006 slow slip event (SSE) in Guerrero, Mexico, as opposed to Cascadia, where tremor locations and rupture zones of SSEs largely overlap. Here we obtain high resolution tremor locations by applying cross-station cross-correlations [Armbruster et al., 2014] to seismic data from the Meso-America Subduction Experiment deployment. A few 3-station detectors are adopted to capture detailed deformation styles in the tremor "transient zone" and the downdip "sweet spot" as defined in Frank et al., 2014. Similar to Cascadia, tremor activities in our study region were comprised mostly of short tremor bursts lasting minutes to hours. Many of these bursts show clear migration patterns with propagation velocities of hundreds of km/day, comparable to those in Cascadia. However, the propagation of the main tremor front was often not in a simple unilateral fashion. Before the 2006 SSE, we observe 4 large tremor episodes during which both the transient zone and the sweet spot participated, consistent with previous findings [Frank et al., 2014]. The transient zone usually became active a few days after the sweet spot. We find many along-dip migrations with recurrence intervals of about a half day within a region about 10 km along strike and 35 km along dip in the sweet spot, suggesting possible tidal modulation, after the main front moved beyond this region. These migrations appear not to originate at the main front, in contrast to tremor migrations from a few km to tens of km across observed in Cascadia [Rubin and Armbruster, 2013; Peng et al., 2015; Peng and Rubin, submitted], but possibly similar to Shikoku, Japan [Shelly et al., 2007]. We do not observe obvious half-day periodicity for the migrations farther downdip within the sweet spot. During the SSE, the recurrence interval of tremor episodes decreased significantly in both the transient zone and the sweet spot, with that of the former being much shorter

  11. Analysis of a ceramic head being part of a modular hip prosthesis with the possibility of a conical error; Individuazione dello stato tensionale in una testina in materiale ceramico per protesi d`anca con un errore di conicita` del I tipo nel suo accoppiamento con lo stelo

    Energy Technology Data Exchange (ETDEWEB)

    Ravagli, E.; Vaccari, M. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dipt. Innovazione

    1997-11-01

    This report still pursues the aim of carrying out a systematic mechanical analysis of a ceramic head being part of a modular hip prosthesis, in order to characterize it exhaustively, i.e. to assess its performances and some of its main specifications. Here in particular the aim is to locate the stress of the head when it undergoes the load transferred by the stem, presuming that the stem-head mating is not perfect, but there is a conical error called of the 1st type, to which corresponds a stem summit angle bigger than the one in the head hole. This conical error changes considerably the head stress and therefore this study is considered decisive for a later correct assessment of its resistance to breaking. This study is performed in the frame of the STRIDE-CETMA Project.

  12. Iron accumulation and dysregulation in the putamen in fragile X-associated tremor/ataxia syndrome.

    Science.gov (United States)

    Ariza, Jeanelle; Rogers, Hailee; Hartvigsen, Anna; Snell, Melissa; Dill, Michael; Judd, Derek; Hagerman, Paul; Martínez-Cerdeño, Verónica

    2017-04-01

    Fragile X-associated tremor/ataxia syndrome is an adult-onset disorder associated with premutation alleles of the FMR1 gene. This disorder is characterized by progressive action tremor, gait ataxia, and cognitive decline. Fragile X-associated tremor/ataxia syndrome pathology includes dystrophic white matter and intranuclear inclusions in neurons and astrocytes. We previously demonstrated that the transport of iron into the brain is altered in fragile X-associated tremor/ataxia syndrome; therefore, we also expect an alteration of iron metabolism in brain areas related to motor control. Iron is essential for cell metabolism, but uncomplexed iron leads to oxidative stress and contributes to the development of neurodegenerative diseases. We investigated a potential iron modification in the putamen - a structure that participates in motor learning and performance - in fragile X-associated tremor/ataxia syndrome. We used samples of putamen obtained from 9 fragile X-associated tremor/ataxia syndrome and 9 control cases to study iron localization using Perl's method, and iron-binding proteins using immunostaining. We found increased iron deposition in neuronal and glial cells in the putamen in fragile X-associated tremor/ataxia syndrome. We also found a generalized decrease in the amount of the iron-binding proteins transferrin and ceruloplasmin, and decreased number of neurons and glial cells that contained ceruloplasmin. However, we found increased levels of iron, transferrin, and ceruloplasmin in microglial cells, indicating an attempt by the immune system to remove the excess iron. Overall, found a deficit in proteins that eliminate extra iron from the cells with a concomitant increase in the deposit of cellular iron in the putamen in Fragile X-associated tremor/ataxia syndrome. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  13. Surface-wave potential for triggering tectonic (nonvolcanic) tremor-corrected

    Science.gov (United States)

    Hill, David P.

    2012-01-01

    Source processes commonly posed to explain instances of remote dynamic triggering of tectonic (nonvolcanic) tremor by surface waves include frictional failure and various modes of fluid activation. The relative potential for Love- and Rayleigh-wave dynamic stresses to trigger tectonic tremor through failure on critically stressed thrust and vertical strike-slip faults under the Coulomb-Griffith failure criteria as a function of incidence angle are anticorrelated over the 15- to 30-km-depth range that hosts tectonic tremor. Love-wave potential is high for strike-parallel incidence on low-angle reverse faults and null for strike-normal incidence; the opposite holds for Rayleigh waves. Love-wave potential is high for both strike-parallel and strike-normal incidence on vertical, strike-slip faults and minimal for ~45° incidence angles. The opposite holds for Rayleigh waves. This pattern is consistent with documented instances of tremor triggered by Love waves incident on the Cascadia megathrust and the San Andreas fault (SAF) in central California resulting from shear failure on weak faults (apparent friction is μ* ≤ 0:2). Documented instances of tremor triggered by surface waves with strike-parallel incidence along the Nankai megathrust beneath Shikoku, Japan, however, are associated primarily with Rayleigh waves. This is consistent with the tremor bursts resulting from mixed-mode failure (crack opening and shear failure) facilitated by near-lithostatic ambient pore pressure, low differential stress, with a moderate friction coefficient (μ ~ 0:6) on the Nankai subduction interface. Rayleigh-wave dilatational stress is relatively weak at tectonic tremor source depths and seems unlikely to contribute significantly to the triggering process, except perhaps for an indirect role on the SAF in sustaining tremor into the Rayleigh-wave coda that was initially triggered by Love waves.

  14. Changes of Physiological Tremor Following Maximum Intensity Exercise in Male and Female Young Swimmers

    Directory of Open Access Journals (Sweden)

    Gajewski Jan

    2015-12-01

    Full Text Available Purpose. The aim of this study was to determine the changes in postural physiological tremor following maximum intensity effort performed on arm ergometer by young male and female swimmers. Methods. Ten female and nine male young swimmers served as subjects in the study. Forearm tremor was measured accelerometrically in the sitting position before the 30-second Wingate Anaerobic Test on arm ergometer and then 5, 15 and 30 minutes post-test. Results. Low-frequency tremor log-amplitude (L1−5 increased (repeated factor: p < 0.05 from −7.92 ± 0.45 to −7.44 ± 0.45 and from −6.81 ± 0.52 to −6.35 ± 0.58 in women and men, respectively (gender: p < 0.05 5 minute post-test. Tremor log-amplitude (L15−20 increased (repeated factor: p < 0.001 from −9.26 ± 0.70 to −8.59 ± 0.61 and from −8.79 ± 0.65 to −8.39 ± 0.79 in women and men, respectively 5 minute post-test. No effect of gender was found for high frequency range.The increased tremor amplitude was observed even 30 minute post-exercise. Mean frequency of tremor spectra gradually decreased post-exercises (p < 0.001. Conclusions. Exercise-induced changes in tremor were similar in males and females. A fatigue produced a decrement in the mean frequency of tremor what suggested decreased muscle stiffness post-exercise. Such changes intremorafter exercise may be used as the indicator of fatigue in the nervous system.

  15. Long-Term Efficacy of Constant Current Deep Brain Stimulation in Essential Tremor.

    Science.gov (United States)

    Rezaei Haddad, Ali; Samuel, Michael; Hulse, Natasha; Lin, Hsin-Ying; Ashkan, Keyoumars

    2017-07-01

    Ventralis intermedius deep brain stimulation is an established intervention for medication-refractory essential tremor. Newer constant current stimulation technology offers theoretical advantage over the traditional constant voltage systems in terms of delivering a more biologically stable therapy. There are no previous reports on the outcomes of constant current deep brain stimulation in the treatment of essential tremor. This study aimed to evaluate the long-term efficacy of ventralis intermedius constant current deep brain stimulation in patients diagnosed with essential tremor. Essential tremor patients implanted with constant current deep brain stimulation for a minimum of three years were evaluated. Clinical outcomes were assessed using the Fahn-Tolosa-Marin tremor rating scale at baseline and postoperatively at the time of evaluation. The quality of life in the patients was assessed using the Quality of Life in Essential Tremor questionnaire. Ten patients were evaluated with a median age at evaluation of 74 years (range 66-79) and a mean follow up time of 49.7 (range 36-78) months since starting stimulation. Constant current ventralis intermedius deep brain stimulation was well tolerated and effective in all patients with a mean score improvement from 50.7 ± 5.9 to 17.4 ± 5.7 (p = 0.0020) in the total Fahn-Tolosa-Marin rating scale score (65.6%). Furthermore, the total combined mean Quality of Life in Essential Tremor score was improved from 56.2 ± 4.9 to 16.8 ± 3.5 (p value = 0.0059) (70.1%). This report shows that long-term constant current ventralis intermedius deep brain stimulation is a safe and effective intervention for essential tremor patients. © 2017 International Neuromodulation Society.

  16. Autosomal dominant cortical tremor, myoclonus, and epilepsy (ADCME: Probable first family from India

    Directory of Open Access Journals (Sweden)

    Chandra Mohan Sharma

    2014-01-01

    Full Text Available Autosomal dominant cortical tremor, myoclonus, and epilepsy (ADCME is an extremely rare syndrome characterized by familial occurrence of postural and action-induced tremors of the hands but showing electrophysiologic findings of cortical reflex myoclonus. Patients also have cognitive decline and tonic-clonic seizures, often precipitated by sleep deprivation or photic stimulation. We describe probably the first family from India of this ill-defined syndrome.

  17. Ambient seismic noise interferometry in Hawai'i reveals long-range observability of volcanic tremor

    Science.gov (United States)

    Ballmer, Silke; Wolfe, Cecily; Okubo, Paul G.; Haney, Matt; Thurber, Clifford H.

    2013-01-01

    The use of seismic noise interferometry to retrieve Green's functions and the analysis of volcanic tremor are both useful in studying volcano dynamics. Whereas seismic noise interferometry allows long-range extraction of interpretable signals from a relatively weak noise wavefield, the characterization of volcanic tremor often requires a dense seismic array close to the source. We here show that standard processing of seismic noise interferometry yields volcanic tremor signals observable over large distances exceeding 50 km. Our study comprises 2.5 yr of data from the U.S. Geological Survey Hawaiian Volcano Observatory short period seismic network. Examining more than 700 station pairs, we find anomalous and temporally coherent signals that obscure the Green's functions. The time windows and frequency bands of these anomalous signals correspond well with the characteristics of previously studied volcanic tremor sources at Pu'u 'Ō'ō and Halema'uma'u craters. We use the derived noise cross-correlation functions to perform a grid-search for source location, confirming that these signals are surface waves originating from the known tremor sources. A grid-search with only distant stations verifies that useful tremor signals can indeed be recovered far from the source. Our results suggest that the specific data processing in seismic noise interferometry—typically used for Green's function retrieval—can aid in the study of both the wavefield and source location of volcanic tremor over large distances. In view of using the derived Green's functions to image heterogeneity and study temporal velocity changes at volcanic regions, however, our results illustrate how care should be taken when contamination by tremor may be present.

  18. How to Tackle Tremor – Systematic Review of the Literature and Diagnostic Work-Up

    Science.gov (United States)

    Buijink, A. W. G.; Contarino, M. F.; Koelman, J. H. T. M.; Speelman, J. D.; van Rootselaar, A. F.

    2012-01-01

    Background: Tremor is the most prevalent movement disorder in clinical practice. It is defined as involuntary, rhythmic, oscillatory movements. The diagnostic process of patients with tremor can be laborious and challenging, and a clear, systematic overview of available diagnostic techniques is lacking. Tremor can be a symptom of many diseases, but can also represent a distinct disease entity. Objective: The objective of this review is to give a clear, systematic and step-wise overview of the diagnostic work-up of a patient with tremor. The clinical relevance and value of available laboratory tests in patients with tremor will be explored. Methods: We systematically searched through EMBASE. The retrieved articles were supplemented by articles containing relevant data or provided important background information. Studies that were included investigated the value and/or usability of diagnostic tests for tremor. Results: In most patients, history and clinical examination by an experienced movement disorders neurologist are sufficient to establish a correct diagnosis, and further ancillary examinations will not be needed. Ancillary investigation should always be guided by tremor type(s) present and other associated signs and symptoms. The main ancillary examination techniques currently are electromyography and SPECT imaging. Unfortunately, many techniques have not been studied in large prospective, diagnostic studies to be able to determine important variables like sensitivity and specificity. Conclusion: When encountering a patient with tremor, history, and careful clinical examination should guide the diagnostic process. Adherence to the diagnostic work-up provided in this review will help the diagnostic process of these patients. PMID:23109928

  19. A phase coherence approach to identifying co-located earthquakes and tremor

    Science.gov (United States)

    Hawthorne, J. C.; Ampuero, J.-P.

    2017-05-01

    We present and use a phase coherence approach to identify seismic signals that have similar path effects but different source time functions: co-located earthquakes and tremor. The method used is a phase coherence-based implementation of empirical matched field processing, modified to suit tremor analysis. It works by comparing the frequency-domain phases of waveforms generated by two sources recorded at multiple stations. We first cross-correlate the records of the two sources at a single station. If the sources are co-located, this cross-correlation eliminates the phases of the Green's function. It leaves the relative phases of the source time functions, which should be the same across all stations so long as the spatial extent of the sources are small compared with the seismic wavelength. We therefore search for cross-correlation phases that are consistent across stations as an indication of co-located sources. We also introduce a method to obtain relative locations between the two sources, based on back-projection of interstation phase coherence. We apply this technique to analyse two tremor-like signals that are thought to be composed of a number of earthquakes. First, we analyse a 20 s long seismic precursor to a M 3.9 earthquake in central Alaska. The analysis locates the precursor to within 2 km of the mainshock, and it identifies several bursts of energy-potentially foreshocks or groups of foreshocks-within the precursor. Second, we examine several minutes of volcanic tremor prior to an eruption at Redoubt Volcano. We confirm that the tremor source is located close to repeating earthquakes identified earlier in the tremor sequence. The amplitude of the tremor diminishes about 30 s before the eruption, but the phase coherence results suggest that the tremor may persist at some level through this final interval.

  20. Abnormal climbing fibre-Purkinje cell synaptic connections in the essential tremor cerebellum.

    Science.gov (United States)

    Lin, Chi-Ying; Louis, Elan D; Faust, Phyllis L; Koeppen, Arnulf H; Vonsattel, Jean-Paul G; Kuo, Sheng-Han

    2014-12-01

    Structural changes in Purkinje cells have been identified in the essential tremor cerebellum, although the mechanisms that underlie these changes remain poorly understood. Climbing fibres provide one of the major excitatory inputs to Purkinje cells, and climbing fibre-Purkinje cell connections are essential for normal cerebellar-mediated motor control. The distribution of climbing fibre-Purkinje cell synapses on Purkinje cell dendrites is dynamically regulated and may be altered in disease states. The aim of the present study was to examine the density and distribution of climbing fibre-Purkinje cell synapses using post-mortem cerebellar tissue of essential tremor cases and controls. Using vesicular glutamate transporter type 2 immunohistochemistry, we labelled climbing fibre-Purkinje cell synapses of 12 essential tremor cases and 13 age-matched controls from the New York Brain Bank. Normally, climbing fibres form synapses mainly on the thick, proximal Purkinje cell dendrites in the inner portion of the molecular layer, whereas parallel fibres form synapses on the thin, distal Purkinje cell spiny branchlets. We observed that, compared with controls, essential tremor cases had decreased climbing fibre-Purkinje cell synaptic density, more climbing fibres extending to the outer portion of the molecular layer, and more climbing fibre-Purkinje cell synapses on the thin Purkinje cell spiny branchlets. Interestingly, in essential tremor, the increased distribution of climbing fibre-Purkinje cell synapses on the thin Purkinje cell branchlets was inversely associated with clinical tremor severity, indicating a close relationship between the altered distribution of climbing fibre-Purkinje cell connections and tremor. These findings suggest that abnormal climbing fibre-Purkinje cell connections could be of importance in the pathogenesis of essential tremor. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved

  1. Understanding Tremor in Multiple Sclerosis: Prevalence, Pathological Anatomy, and Pharmacological and Surgical Approaches to Treatment

    OpenAIRE

    Labiano-Fontcuberta, Andrés; Benito-León, Julián

    2012-01-01

    Background Given that tremor is one of the most prevalent and disabling features of multiple sclerosis (MS), we will review the most significant milestones in tremor in this disease in recent years, focusing on prevalence, clinical features, anatomical basis, and treatment. Methods Data for this review were identified by searching MEDLINE with the search terms “multiple sclerosis” and “tremor”. References were also identified from relevant articles published between January 1966 and May 2012....

  2. How to tackle tremor – systematic review of the literature and diagnostic work-up

    Directory of Open Access Journals (Sweden)

    Arthur W.G. Buijink

    2012-10-01

    Full Text Available BackgroundTremor is the most prevalent movement disorder in clinical practice. It is defined as involuntary, rhythmic, oscillatory movements. The diagnostic process of patients with tremor can be laborious and challenging, and a clear, systematic overview of available diagnostic techniques is lacking. Tremor can be a symptom of many diseases, but can also represent a distinct disease entity.ObjectiveThe objective of this review is to give a clear, systematic and step-wise overview of the diagnostic work-up of a patient with tremor. The clinical relevance and value of available laboratory tests in patients with tremor will be explored.MethodsWe systematically searched through EMBASE. The retrieved articles were supplemented by articles containing relevant data or provided important background information. Studies that were included investigated the value and/or usability of diagnostic tests for tremor.ResultsIn most patients, history and clinical examination by an experienced movement disorders neurologist are sufficient to establish a correct diagnosis, and further ancillary examinations will not be needed. Ancillary investigation should always be guided by tremor type(s present and other associated signs and symptoms. The main ancillary examination techniques currently are electromyography and SPECT imaging. Unfortunately, many techniques have not been studied in large prospective, diagnostic studies to be able to determine important variables like sensitivity and specificity.ConclusionWhen encountering a patient with tremor, history and careful clinical examination should guide the diagnostic process. Adherence to the diagnostic work-up provided in this review will help the diagnostic process of these patients.

  3. Voice handicap in essential tremor: a comparison with normal controls and Parkinson's disease.

    Science.gov (United States)

    Louis, Elan D; Gerbin, Marina

    2013-01-01

    Although voice tremor is one of the most commonly noted clinical features of essential tremor (ET), there are nearly no published data on the handicap associated with it. The Voice Handicap Index (VHI) was self-administered by participants enrolled in a research study at Columbia University Medical Center. The VHI quantifies patients' perceptions of handicap due to voice difficulties. Data from 98 ET cases were compared with data from 100 controls and 85 patients with another movement disorder (Parkinson's disease, PD). Voice tremor was present on examination in 25 (25.5%) ET cases; 12 had mild voice tremor (ETMild VT) and 13 had marked voice tremor (ETMarked VT). VHI scores were higher in ET cases than controls (p = 0.02). VHI scores among ETMarked VT were similar to those of PD cases; both were significantly higher than controls (phandicap associated with ET had multiple (i.e., physical, functional, and emotional) dimensions. Moreover, ET cases with marked voice tremor on examination had a level of self-reported voice handicap that was similar to that observed in patients with PD.

  4. Astrovirus as a possible cause of congenital tremor type AII in piglets?

    Science.gov (United States)

    Blomström, Anne-Lie; Ley, Cecilia; Jacobson, Magdalena

    2014-12-16

    Congenital tremor is associated with demyelination of the brain and spinal cord and is clinically noted as outbreaks of trembling and shaking in newborn piglets during a limited time-period. Six forms of the disease have been described, where form AII may be caused by an, as yet, unidentified viral infection. This study aimed to investigate the presence of astrovirus and circovirus by sequencing and polymerase chain reaction (PCR) analysis and by relating the findings to the occurrence of disease and lesions in the brain, in 4-6 days-old piglets obtained from a clinical outbreak of congenital tremor. In piglets with congenital tremor, there were mild to moderate vacuolar changes of the white matter in the cerebrum, brain stem and cerebellum. In healthy piglets, less conspicuous vacuolar changes were detected. One healthy and one diseased piglet were positive for porcine circovirus type 2. The nested pan-PCR showed the presence of astrovirus in at least one brain region in all piglets and by sequencing, two different porcine astrovirus lineages were identified. The results do not support previous studies identifying porcine circovirus type 2 as the cause of congenital tremor. The demonstration of astrovirus in the brain of piglets suffering from congenital tremor is interesting. However, astrovirus was demonstrated in both healthy and diseased individuals and therefore, further studies are warranted to determine the possible involvement of astrovirus in the pathogenesis of congenital tremor in pigs.

  5. The influence of pitch and loudness changes on the acoustics of vocal tremor.

    Science.gov (United States)

    Dromey, Christopher; Warrick, Paul; Irish, Jonathan

    2002-10-01

    The effect of tremor on phonation is to modulate an otherwise steady sound source in its amplitude, fundamental frequency, or both. The severity of untreated vocal tremor has been reported to change under certain conditions that may be related to muscle tension. In order to better understand the phenomenon of vocal tremor, its acoustic properties were examined as individuals volitionally altered their pitch and loudness. These voice conditions were anticipated to alter the tension of the intrinsic laryngeal muscles. The voices of 10 individuals with a diagnosis of vocal tremor were recorded before participating in a longitudinal treatment study. They produced vowels at low and high pitch and loudness levels as well as in a comfortable voice condition. Acoustic analyses quantified the amplitude and frequency modulations of the speakers' voices across the various conditions. Individual speakers varied in the way the pitch and loudness changes affected their tremor, but the following statistically significant effects for the speakers as a group were observed: Higher pitch phonation was associated with a more rapid rate for both amplitude and frequency modulations. Amplitude modulation become faster for louder phonation. Low-pitched phonotion led to decreases in the extent of amplitude tremor. Varying pitch led to dramatic changes in the phase relationship between amplitude and frequency modulation in some of the speakers, whereas this effect was not apparent in other speakers.

  6. Effect of mental fatigue on induced tremor in human knee extensors.

    Science.gov (United States)

    Budini, Francesco; Lowery, Madeleine; Durbaba, Rade; De Vito, Giuseppe

    2014-06-01

    In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6Hz) and high (8-12Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100min of a mental fatigue task, in 12 healthy (29±3.7years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12Hz tremor and had no effect on induced 3-6Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Frictional-faulting model for harmonic tremor before Redoubt Volcano eruptions

    Science.gov (United States)

    Dmitrieva, Ksenia; Hotovec-Ellis, Alicia J.; Prejean, Stephanie G.; Dunham, Eric M.

    2013-01-01

    Seismic unrest, indicative of subsurface magma transport and pressure changes within fluid-filled cracks and conduits, often precedes volcanic eruptions. An intriguing form of volcano seismicity is harmonic tremor, that is, sustained vibrations in the range of 0.5–5 Hz. Many source processes can generate harmonic tremor. Harmonic tremor in the 2009 eruption of Redoubt Volcano, Alaska, has been linked to repeating earthquakes of magnitudes around 0.5–1.5 that occur a few kilometres beneath the vent. Before many explosions in that eruption, these small earthquakes occurred in such rapid succession—up to 30 events per second—that distinct seismic wave arrivals blurred into continuous, high-frequency tremor. Tremor abruptly ceased about 30 s before the explosions. Here we introduce a frictional-faulting model to evaluate the credibility and implications of this tremor mechanism. We find that the fault stressing rates rise to values ten orders of magnitude higher than in typical tectonic settings. At that point, inertial effects stabilize fault sliding and the earthquakes cease. Our model of the Redoubt Volcano observations implies that the onset of volcanic explosions is preceded by active deformation and extreme stressing within a localized region of the volcano conduit, at a depth of several kilometres.

  8. Simulations of tremor-related creep reveal a weak crustal root of the San Andreas Fault

    Science.gov (United States)

    Shelly, David R.; Bradley, Andrew M.; Johnson, Kaj M.

    2013-01-01

    Deep aseismic roots of faults play a critical role in transferring tectonic loads to shallower, brittle crustal faults that rupture in large earthquakes. Yet, until the recent discovery of deep tremor and creep, direct inference of the physical properties of lower-crustal fault roots has remained elusive. Observations of tremor near Parkfield, CA provide the first evidence for present-day localized slip on the deep extension of the San Andreas Fault and triggered transient creep events. We develop numerical simulations of fault slip to show that the spatiotemporal evolution of triggered tremor near Parkfield is consistent with triggered fault creep governed by laboratory-derived friction laws between depths of 20–35 km on the fault. Simulated creep and observed tremor northwest of Parkfield nearly ceased for 20–30 days in response to small coseismic stress changes of order 104 Pa from the 2003 M6.5 San Simeon Earthquake. Simulated afterslip and observed tremor following the 2004 M6.0 Parkfield earthquake show a coseismically induced pulse of rapid creep and tremor lasting for 1 day followed by a longer 30 day period of sustained accelerated rates due to propagation of shallow afterslip into the lower crust. These creep responses require very low effective normal stress of ~1 MPa on the deep San Andreas Fault and near-neutral-stability frictional properties expected for gabbroic lower-crustal rock.

  9. Voice Handicap in Essential Tremor: A Comparison with Normal Controls and Parkinson’s Disease

    Science.gov (United States)

    Louis, Elan D.; Gerbin, Marina

    2013-01-01

    Background Although voice tremor is one of the most commonly noted clinical features of essential tremor (ET), there are nearly no published data on the handicap associated with it. Methods The Voice Handicap Index (VHI) was self-administered by participants enrolled in a research study at Columbia University Medical Center. The VHI quantifies patients’ perceptions of handicap due to voice difficulties. Data from 98 ET cases were compared with data from 100 controls and 85 patients with another movement disorder (Parkinson’s disease, PD). Results Voice tremor was present on examination in 25 (25.5%) ET cases; 12 had mild voice tremor (ETMild VT) and 13 had marked voice tremor (ETMarked VT). VHI scores were higher in ET cases than controls (p = 0.02). VHI scores among ETMarked VT were similar to those of PD cases; both were significantly higher than controls (phandicap associated with ET had multiple (i.e., physical, functional, and emotional) dimensions. Moreover, ET cases with marked voice tremor on examination had a level of self-reported voice handicap that was similar to that observed in patients with PD. PMID:23450107

  10. Successful Treatment of Rubral Tremor by High-Dose Trihexyphenidyl: A Case Report

    Directory of Open Access Journals (Sweden)

    Li-Min Liou

    2006-03-01

    Full Text Available A 24-year-old male suffered from acute-onset right-sided hemiparesis, dysarthria, and ophthalmoplegia in February 2001. Brain magnetic resonance imaging revealed a cavernous angioma with hemorrhage over the left thalamus. Moreover, some rhythmic, coarse, low-frequency (2-3 Hz oscillation over the right wrist and elbow was noted 1 month later. Action tremor was more predominant than resting tremor. Rubral tremor was diagnosed on the basis of the clinical presentation and tremography analysis. Rubral tremor is not unusual, and pharmacotherapy is nearly always ineffective in clinical practice. Deep brain stimulation, thalamotomy, and pallidotomy are all considered effective according to recent research. However, they are either very expensive or invasive, and involve surgical risks. In our patient, we tried valproate, clonazepam, and verapamil one after another, but all in vain. Finally, titration of trihexyphenidyl provided significant benefit. The tremor was successfully controlled by a single high daily dose of trihexyphenidyl (38 mg without severe or uncomfortable side effects. Here, we report a case of successful monotherapy of rubral tremor with high-dose trihexyphenidyl.

  11. Methodology for estimating human perception to tremors in high-rise buildings

    Science.gov (United States)

    Du, Wenqi; Goh, Key Seng; Pan, Tso-Chien

    2017-07-01

    Human perception to tremors during earthquakes in high-rise buildings is usually associated with psychological discomfort such as fear and anxiety. This paper presents a methodology for estimating the level of perception to tremors for occupants living in high-rise buildings subjected to ground motion excitations. Unlike other approaches based on empirical or historical data, the proposed methodology performs a regression analysis using the analytical results of two generic models of 15 and 30 stories. The recorded ground motions in Singapore are collected and modified for structural response analyses. Simple predictive models are then developed to estimate the perception level to tremors based on a proposed ground motion intensity parameter—the average response spectrum intensity in the period range between 0.1 and 2.0 s. These models can be used to predict the percentage of occupants in high-rise buildings who may perceive the tremors at a given ground motion intensity. Furthermore, the models are validated with two recent tremor events reportedly felt in Singapore. It is found that the estimated results match reasonably well with the reports in the local newspapers and from the authorities. The proposed methodology is applicable to urban regions where people living in high-rise buildings might feel tremors during earthquakes.

  12. Quantification of a Secondary Task-Specific Tremor in a Violinist after a Temporal Lobectomy

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    André eLee

    2014-07-01

    Full Text Available Task-specific tremors occur mainly during certain tasks and may be highly disabling. In this case study, we report on a 66-year-old violinist who developed a task-specific tremor of the right arm only while playing the violin four weeks after a temporal lobectomy, which had been performed as a result of his temporal lobe epilepsy. Since a similar case, to our knowledge, has not been reported so far, our aim was to quantitatively assess and describe the tremor by measuring (a the electromyography (EMG activity of the wrist flexor and extensor as well as (b an accelerometer signal of the hand. We found a tremor-related frequency of about 7 Hz. Furthermore, at a similar frequency of about 7 Hz, there was coherence between the tremor acceleration and EMG-activity of the wrist flexor and extensor as well as between the tremor acceleration and coactivation. The tremorgenesis remains unclear, and possible explanations can only be speculative.

  13. Intraoperative acceleration measurements to quantify improvement in tremor during deep brain stimulation surgery.

    Science.gov (United States)

    Shah, Ashesh; Coste, Jérôme; Lemaire, Jean-Jacques; Taub, Ethan; Schüpbach, W M Michael; Pollo, Claudio; Schkommodau, Erik; Guzman, Raphael; Hemm-Ode, Simone

    2017-05-01

    Deep brain stimulation (DBS) surgery is extensively used in the treatment of movement disorders. Nevertheless, methods to evaluate the clinical response during intraoperative stimulation tests to identify the optimal position for the implantation of the chronic DBS lead remain subjective. In this paper, we describe a new, versatile method for quantitative intraoperative evaluation of improvement in tremor with an acceleration sensor that is mounted on the patient's wrist during surgery. At each anatomical test position, the improvement in tremor compared to the initial tremor is estimated on the basis of extracted outcome measures. This method was tested on 15 tremor patients undergoing DBS surgery in two centers. Data from 359 stimulation tests were acquired. Our results suggest that accelerometric evaluation detects tremor changes more sensitively than subjective visual ratings. The effective stimulation current amplitudes identified from the quantitative data (1.1 ± 0.8 mA) are lower than those identified by visual evaluation (1.7 ± 0.8 mA) for similar improvement in tremor. Additionally, if these data had been used to choose the chronic implant position of the DBS lead, 15 of the 26 choices would have been different. These results show that our method of accelerometric evaluation can potentially improve DBS targeting.

  14. Intermittent tremor migrations beneath Guerrero, Mexico, and implications for fault healing within the slow slip zone

    Science.gov (United States)

    Peng, Yajun; Rubin, Allan M.

    2017-01-01

    Slow slip events exhibit significant complexity in slip evolution and variations in recurrence intervals. Behavior that varies systematically with recurrence interval is likely to reflect different extents of fault healing between these events. Here we use high-resolution tremor catalogs beneath Guerrero, Mexico, to investigate the mechanics of slow slip. We observe complex tremor propagation styles, including rapid tremor migrations propagating either along the main tremor front or backward, reminiscent of those in northern Cascadia. We also find many migrations that originate well behind the front and repeatedly occupy the same source region during a tremor episode, similar to those previously reported from Shikoku, Japan. These migrations could be driven by slow slip in the surrounding regions, with recurrence intervals possibly modulated by tides. The propagation speed of these migrations decreases systematically with time since the previous migration over the same source area. Tremor amplitudes seem consistent with changes in the propagation speeds being controlled primarily by changes in the slip speeds. One interpretation is that the high propagation speeds and inferred high slip speeds during the migrations with short recurrence intervals are caused by incomplete healing within the host rock adjacent to the shear zone, which could lead to high permeability and reduced dilatant strengthening of the fault gouge. Similar processes may operate in other slow slip source regions such as Cascadia.

  15. Spatio-temporal distribution of energy radiation from low frequency tremor

    Science.gov (United States)

    Maeda, T.; Obara, K.

    2007-12-01

    Recent fine-scale hypocenter locations of low frequency tremors (LFTs) estimated by cross-correlation technique (Shelly et al. 2006; Maeda et al. 2006) and new finding of very low frequency earthquake (Ito et al. 2007) suggest that these slow events occur at the plate boundary associated with slow slip events (Obara and Hirose, 2006). However, the number of tremor detected by above technique is limited since continuous tremor waveforms are too complicated. Although an envelope correlation method (ECM) (Obara, 2002) enables us to locate epicenters of LFT without arrival time picks, however, ECM fails to locate LFTs precisely especially on the most active stage of tremor activity because of the low-correlation of envelope amplitude. To reveal total energy release of LFT, here we propose a new method for estimating the location of LFTs together with radiated energy from the tremor source by using envelope amplitude. The tremor amplitude observed at NIED Hi-net stations in western Shikoku simply decays in proportion to the reciprocal of the source-receiver distance after the correction of site- amplification factor even though the phases of the tremor are very complicated. So, we model the observed mean square envelope amplitude by time-dependent energy radiation with geometrical spreading factor. In the model, we do not have origin time of the tremor since we assume that the source of the tremor continuously radiates the energy. Travel-time differences between stations estimated by the ECM technique also incorporated in our locating algorithm together with the amplitude information. Three-component 1-hour Hi-net velocity continuous waveforms with a pass-band of 2-10 Hz are used for the inversion after the correction of site amplification factors at each station estimated by coda normalization method (Takahashi et al. 2005) applied to normal earthquakes in the region. The source location and energy are estimated by applying least square inversion to the 1-min window

  16. Effects of vision and arm position on amplitude of arm postural tremor in patients with multiple sclerosis.

    Science.gov (United States)

    Feys, Peter; Helsen, Werner F; Liu, Xuguang; Lavrysen, Ann; Nuttin, Bart; Ketelaer, Piet

    2004-06-01

    To quantify the effects of vision and arm position on arm postural tremor, comparisons were made between flexed and extended arm positions performed with the eyes open and closed. Case-control study. National multiple sclerosis (MS) center in Belgium. Sixteen patients (32 arms) with MS who had intention tremor and 16 healthy controls (32 arms). Not applicable. The amplitude of postural tremor was assessed by a magnetic position sensor attached to the index finger. The amplitude of postural tremor was not influenced by changes in visual condition or different arm positions. Both healthy controls and MS patients made more directional changes in the flexed, compared with the extended arm position. The amplitude of the arm postural tremor in MS is independent of vision and arm position. Selecting 1 arm position is sufficient to assess postural tremor amplitude.

  17. Diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT: A clinical follow up study

    Directory of Open Access Journals (Sweden)

    Manuel eMenéndez-González

    2014-04-01

    Full Text Available The [123I]ioflupane - a dopamine transporter radioligand - SPECT (DaT-SPECT has proven to be useful in the differential diagnosis of tremor. Here, we investigate the diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT. Therefore, 30 patients with tremor and normal DaT-SPECT were followed up for 2 years. In 18 cases we were able to make a diagnosis. The residual 12 patients underwent a second DaT-SPECT, were then followed for additional 12 months and thereafter the diagnosis was reconsidered again. The final diagnoses included cases of essential tremor, dystonic tremor, multisystem atrophy, vascular parkinsonism, progressive supranuclear palsy, corticobasal degeneration, fragile X–associated tremor ataxia syndrome, psychogenic parkinsonism, iatrogenic parkinsonism and Parkinson’s disease. However, for 6 patients the diagnosis remained uncertain. Larger series are needed to better establish the relative frequency of the different conditions behind these cases.

  18. Diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT: a clinical follow up study

    Science.gov (United States)

    Menéndez-González, Manuel; Tavares, Francisco; Zeidan, Nahla; Salas-Pacheco, José M.; Arias-Carrión, Oscar

    2014-01-01

    The [123I]ioflupane—a dopamine transporter radioligand—SPECT (DaT-SPECT) has proven to be useful in the differential diagnosis of tremor. Here, we investigate the diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT. Therefore, 30 patients with tremor and normal DaT-SPECT were followed up for 2 years. In 18 cases we were able to make a diagnosis. The residual 12 patients underwent a second DaT-SPECT, were then followed for additional 12 months and thereafter the diagnosis was reconsidered again. The final diagnoses included cases of essential tremor, dystonic tremor, multisystem atrophy, vascular parkinsonism, progressive supranuclear palsy, corticobasal degeneration, fragile X–associated tremor ataxia syndrome, psychogenic parkinsonism, iatrogenic parkinsonism and Parkinson's disease. However, for 6 patients the diagnosis remained uncertain. Larger series are needed to better establish the relative frequency of the different conditions behind these cases. PMID:24744729

  19. Posture, head stability, and orientation recovery during vestibular regeneration in pigeons.

    Science.gov (United States)

    Dickman, J David; Lim, Insook

    2004-09-01

    Compensatory behavior such as oculomotor, gaze, and postural responses that occur during movement largely depend upon a functioning vestibular system. In the present study, the initial loss and subsequent recovery of postural and head stability in pigeons undergoing vestibular regeneration were examined. Adult pigeons were trained to manipulate a straight run chamber to peck an illuminated key for fluid reward. Six behavioral measures assessing performance, posture, and head stability were quantified. These included run latency, steps (walking), path negotiation (lane changes), gaze saccades, head bobs, and head shakes. Once normative values were obtained for four birds, complete lesion of all receptor cells and denervation of the epithelia in the vestibular endorgans were produced using a single intralabyrinthine application of streptomycin sulfate. Each bird was then tested at specific times during regeneration and the same behavioral measures examined. At 7 days post-streptomycin treatment (PST), all birds exhibited severe postural and head instability, with tremors, head shakes, staggering, and circling predominating. No normal trial runs, walking, gaze saccades, or head bobs were present. Many of these dysfunctions persisted through 3-4 weeks PST. Gradually, tremor and head shakes diminished and were replaced with an increasing number of normal head bobs during steps and gaze saccades. Beginning at 4 weeks PST, but largely inaccurate, was the observed initiation of directed steps, less staggering, and some successful path negotiation. As regeneration progressed, spatial orientation and navigation ability increased and, by 49 days PST, most trials were successful. By 70 days PST, all birds had recovered to pretreatment levels. Thus, it was observed that ataxia must subside, coincident with normalized head and postural stability prior to the recovery of spatial orientation and path navigation recovery. Parallels in recovery were drawn to hair cell regeneration

  20. On the singular values decoupling in the Singular Spectrum Analysis of volcanic tremor at Stromboli

    Directory of Open Access Journals (Sweden)

    R. Carniel

    2006-01-01

    Full Text Available The well known strombolian activity at Stromboli volcano is occasionally interrupted by rarer episodes of paroxysmal activity which can lead to considerable hazard for Stromboli inhabitants and tourists. On 5 April 2003 a powerful explosion, which can be compared in size with the latest one of 1930, covered with bombs a good part of the normally tourist-accessible summit area. This explosion was not forecasted, although the island was by then effectively monitored by a dense deployment of instruments. After having tackled in a previous paper the problem of highlighting the timescale of preparation of this event, we investigate here the possibility of highlighting precursors in the volcanic tremor continuously recorded by a short period summit seismic station. We show that a promising candidate is found by examining the degree of coupling between successive singular values that result from the Singular Spectrum Analysis of the raw seismic data. We suggest therefore that possible anomalies in the time evolution of this parameter could be indicators of volcano instability to be taken into account e.g. in a bayesian eruptive scenario evaluator. Obviously, further (and possibly forward testing on other cases is needed to confirm the usefulness of this parameter.

  1. Effective Management of Upper Limb Parkinsonian Tremor by IncobotulinumtoxinA Injections Using Sensor-based Biomechanical Patterns

    Directory of Open Access Journals (Sweden)

    Fariborz Rahimi

    2015-11-01

    Full Text Available Background: Focal treatment of Parkinson’s disease tremor by botulinum toxin type A incobotulinumtoxinA (BoNT-A injections has been inadequately investigated and at best provides modest relief with significant muscle weakness. Complexity of multi-joint tremulous movements results in non-individualized dosing regimens. This 38-week open-label study used kinematic technology to guide muscle selection and improve efficacy of incobotulinumtoxinA (BoNT-A injections for Parkinson’s disease tremor. Methods: Participants (n=28 attended study visits at weeks 0, 6, 16, 22, 32, and 38, and were injected with BoNT-A at weeks 0, 16, and 32. During each visit, clinical tremor scales, the Unified Parkinson’s Disease Rating Scale (UPDRS and the Fahn–Tolosa–Marin (FTM, and kinematic assessments were conducted. Participants performed rest and postural scripted tasks with motion sensors placed over the wrist, elbow, and shoulder joints where tremor was quantified by angular root mean square (RMS amplitude in multiple degrees of freedom at each joint. Injection parameters were determined using the clinician’s interpretation of which muscles would contribute to the upper limb tremor biomechanics analyzed kinematically. Results: Kinematic measures of tremor amplitude allowed detailed segmentation of tremor into directional components at each arm joint permitting a statistically significant decrease in mean UPDRS item 20 (rest tremor at week 16 (p=0.006 and at week 32 (p=0.014, and in FTM tremor severity scores at week 6 (p=0.024. Ten participants perceived mild muscle weakness following the third treatment, which did not interfere with performing activities of daily living. Discussion: Kinematics is a simple method for standardizing assessments and treatment of upper limb Parkinson’s disease tremor, thereby personalizing tremor therapy and optimizing the effect of BoNT-A injections for Parkinson’s disease tremor.

  2. Analyzing the continuous volcanic tremors detected during the 2015 phreatic eruption of the Hakone volcano

    Science.gov (United States)

    Yukutake, Yohei; Honda, Ryou; Harada, Masatake; Doke, Ryosuke; Saito, Tatsuhiko; Ueno, Tomotake; Sakai, Shin'ichi; Morita, Yuichi

    2017-12-01

    In the present study, we analyze the seismic signals from a continuous volcanic tremor that occurred during a small phreatic eruption of the Hakone volcano, in the Owakudani geothermal region of central Japan, on June 29, 2015. The signals were detected for 2 days, from June 29 to July 1, at stations near the vents. The frequency component of the volcanic tremors showed a broad peak within 1-6 Hz. The characteristics of the frequency component did not vary with time and were independent of the amplitude of the tremor. The largest amplitude was observed at the end of the tremor activity, 2 days after the onset of the eruption. We estimated the location of the source using a cross-correlation analysis of waveform envelopes. The locations of volcanic tremors are determined near the vents of eruption and the surface, with the area of the upper extent of an open crack estimated using changes in the tilt. The duration-amplitude distribution of the volcanic tremor was consistent with the exponential scaling law rather than the power law, suggesting a scale-bound source process. This result suggests that the volcanic tremor originated from a similar physical process occurring practically in the same place. The increment of the tremor amplitude was coincident with the occurrence of impulsive infrasonic waves and vent formations. High-amplitude seismic phases were observed prior to the infrasonic onsets. The time difference between the seismic and infrasonic onsets can be explained assuming a common source located at the vent. This result suggests that both seismic and infrasonic waves are generated when a gas slug bursts at that location. The frequency components of the seismic phases observed just before the infrasonic onset were generally consistent with those of the tremor signals without infrasonic waves. The burst of a gas slug at the surface vent may be a reasonable model for the generation mechanism of the volcanic tremor and the occurrence of impulsive infrasonic

  3. Cross-spectral analysis of physiological tremor and muscle activity; 1, Theory and application to unsynchronized EMG

    CERN Document Server

    Timmer, J; Pfleger, W; Deuschl, G

    1998-01-01

    We investigate the relationship between the extensor electromyogram (EMG) and tremor time series in physiological hand tremor by cross-spectral analysis. Special attention is directed to the phase spectrum and the effects of observational noise. We calculate the theoretical phase spectrum for a second order linear stochastic process and compare the results to measured tremor data recorded from subjects who did not show a synchronized EMG activity in the corresponding extensor muscle. The results show that physiological tremor is well described by the proposed model and that the measured EMG represents a Newtonian force by which the muscle acts on the hand.

  4. Effect of nipradilol, a beta-adrenergic blocker with vasodilating activity, on oxotremorine-induced tremor in mice.

    Science.gov (United States)

    Iwata, S; Nomoto, M; Fukuda, T

    1996-10-01

    The effect of nipradilol, a nonselective beta-adrenergic receptor blocker with nitroglycerin-like vasodilating activity, on oxotremorine-induced tremor was studied in mice. General tremor in mice was elicited by 0.5 mg/kg oxotremorine. The tremor was quantified using a capacitance transducer, then analyzed by a signal processor. The strength of the tremor was expressed in "points". The point values of the tremor (mean +/- SE) in control mice for 5 mg/kg (+/-)-propranolol, 2.5 mg/kg arotinolol, 0.5 mg/kg nipradilol, 1.0 mg/kg nipradilol and 2.5 mg/kg nipradilol were 87 +/- 16, 42 +/- 6, 38 +/- 6, 99 +/- 28, 28 +/- 6 and 31 +/- 7, respectively. The strength of the tremor was reduced by all beta-blockers. Although 1.0 mg/kg nipradilol significantly reduced the tremor, further inhibition of the tremor was not obtained with dosages up to 2.5 mg/kg of the drug. In conclusion, nipradilol was effective for suppressing oxotremorine-induced tremor, as were other beta-blockers.

  5. Non-contact measurement of tremor for the characterisation of Parkinsonian individuals: comparison between Kinect and Laser Doppler vibrometer

    Science.gov (United States)

    Casacanditella, L.; Cosoli, G.; Ceravolo, MG; Tomasini, EP

    2017-08-01

    Parkinson’s disease is a progressive neurodegenerative disorder affecting the central nervous system. One of its main and most evident symptoms is the tremor, which usually manifests at rest with varying intensity during time. An important diagnostic challenge is the differential diagnosis between Parkinson’s disease and the other most widely represented tremor syndrome, i.e. Essential (or senile) tremor. At present there are no standard methods for the quantification of tremor and the diagnosis of both Parkinson’s disease and Essential tremor is mainly done on the base of clinical criteria and by using rating scales. The aim of this work is to objectively and non-invasively assess the tremor linked to the quoted diseases, using non-contact techniques: Laser Doppler Vibrometer (LDV) and Kinect for Windows device. Two subjects with Parkinson’s disease and one with Essential tremor were tested in different conditions: at rest, during a cognitive task, with forward stretched arms and in “Wing position”. The results from data processing in terms of tremor frequency seem to be comparable, with a mean deviation of 0.31 Hz. Furthermore, the values computed are consistent with what is stated in the literature (i.e. 4-12 Hz). So, both LDV and Kinect device can be considered suitable to be used as an objective means for the assessment and monitoring of Parkinson’s disease tremor, helping the clinician in the choice of the most suitable treatment for the patients.

  6. Dopamine receptor D3 gene and essential tremor in large series of German, Danish and French patients

    DEFF Research Database (Denmark)

    Lorenz, Delia; Klebe, Stephan; Stevanin, Giovanni

    2008-01-01

    The genetic causes of essential tremor (ET) seem to be heterogeneous. Recently, ET has been found associated with a functional variant (Ser9Gly) of the dopamine D(3) receptor (DRD3), located in the ETM1 locus on chromosome 3q13.3 described for the first time in 1997. We examined this variant...... carried out in 22 ET families. The distribution of genotypes and allele frequencies showed no significant differences in the whole sample and in a subanalysis of familial and sporadic cases. Age at onset of tremor, tremor duration and tremor severity did not show an association with the genotype...

  7. Epidemiology of neurological disorders in India: review of background, prevalence and incidence of epilepsy, stroke, Parkinson's disease and tremors

    National Research Council Canada - National Science Library

    Gourie-Devi, M

    2014-01-01

    ...). Prevalence and incidence rates of common disorders including epilepsy, stroke, Parkinson's disease and tremors determined through population-based surveys show considerable variation across different...

  8. Data Mining for Tectonic Tremor in a Large Global Seismogram Database using Preprocessed Data Quality Measurements

    Science.gov (United States)

    Rasor, B. A.; Brudzinski, M. R.

    2013-12-01

    The collision of plates at subduction zones yields the potential for disastrous earthquakes, yet the processes that lead up to these events are still largely unclear and make them difficult to forecast. Recent advancements in seismic monitoring has revealed subtle ground vibrations termed tectonic tremor that occur as long-lived swarms of narrow bandwidth activity, different from local earthquakes of comparable amplitude that create brief signals of broader, higher frequency. The close proximity of detected tremor events to the lower edge of the seismogenic zone along the subduction interface suggests a potential triggering relationship between tremor and megathrust earthquakes. Most tremor catalogs are constructed with detection methods that involve an exhausting download of years of high sample rate seismic data, as well as large computation power to process the large data volume and identify temporal patterns of tremor activity. We have developed a tremor detection method that employs the underutilized Quality Analysis Control Kit (QuACK), originally built to analyze station performance and identify instrument problems across the many seismic networks that contribute data to one of the largest seismogram databases in the world (IRIS DMC). The QuACK dataset stores seismogram amplitudes at a wide range of frequencies calculated every hour since 2005 for most stations achieved in the IRIS DMC. Such a preprocessed dataset is advantageous considering several tremor detection techniques use hourly seismic amplitudes in the frequency band where tremor is most active (2-5 Hz) to characterize the time history of tremor. Yet these previous detection techniques have relied on downloading years of 40-100 sample-per-second data to make the calculations, which typically takes several days on a 36-node high-performance cluster to calculate the amplitude variations for a single station. Processing times are even longer for a recently developed detection algorithm that utilize

  9. Utility of the Hand-Drawn Spiral as a Tool in Clinical-Epidemiological Research on Essential Tremor: Data From Four Essential Tremor Cohorts

    Science.gov (United States)

    Louis, Elan D.

    2015-01-01

    Background In descriptive epidemiological studies, investigators must screen large numbers of individu