Different Types Of Tremor Research Articles

Different types of tremor and myoclonus in an atypical case of shaking upon standing

Shaking upon standing is associated with a spectrum of different conditions. We describe an unusual case with a combination of slow orthostatic tremor, orthostatic myoclonus, and parkinsonism. The case illustrates the utility of electrophysiology for precise characterization of physical findings to establish the diagnosis.

A Review of Techniques Used to Suppress Tremor

The most frequent movement disorder is Tremor, which has an increased incidence and prevalence in people over 65 who have Parkinson's disease or essential tremors. Although not life-threatening, it prevents patients from performing their daily activities. An overview of different types of tremors and their treatment in medical and surgical views are discussed in this paper with a review of the stimulation nerves and muscles technique. Then a look at tremor detection and measurement methods are considered with a review of the medical devices' mechanism of action that is placed as a substitute treatment for patients that have a low response to medications and surgical treatment to provide effective and safe tremor suppression.

Dystonia and Tremor: A Cross-Sectional Study of the Dystonia Coalition Cohort.

To assess the clinical manifestations and predictors of different types of tremors in individuals with different types of isolated dystonia. Clinical manifestations of tremor were assessed in a multicenter, international cross-sectional, cohort study of 2,362 individuals with all types of isolated dystonia (focal, segmental, multifocal, and generalized) recruited through the Dystonia Coalition. Methodical and standardized assessments of all participants in this cohort revealed the overall prevalence of any type of tremor was 53.3%. The prevalence of dystonic tremor varied from 36.9% to 48.4%, depending on criteria used to define it. To identify the factors associated with tremors in dystonia, the data were analyzed by generalized linear modeling and cluster analyses. Generalized linear modeling indicated 2 of the strongest factors associated with tremor included body region affected by dystonia and recruitment center. Tremor was also associated with severity of dystonia and duration of dystonia, but not with sex or race. The cluster analysis distinguished 8 subgroups within the whole cohort; defined largely by body region with dystonia, and secondarily by other clinical characteristics. The large number of cases evaluated by an international team of movement disorder experts facilitated the dissection of several important factors that influence the apparent prevalence and phenomenology of tremor in dystonia. These results are valuable for understanding the many differences reported in prior studies, and for guiding future studies of the nosology of tremor and dystonia.

Quantitative Assessment of Head Tremor in Patients with Essential Tremor and Cervical Dystonia by Using Inertial Sensors.

Tremor is most common among the movement disabilities that affect older people, having a prevalence rate of 4.6% in the population older than 65 years. Despite this, distinguishing different types of tremors is clinically challenging, often leading to misdiagnosis. However, due to advances in microelectronics and wireless communication, it is now possible to easily monitor tremor in hospitals and even in home environments. In this paper, we propose an architecture of a system for remote health-care and one possible implementation of such system focused on head tremor monitoring. In particular, the aim of the study presented here was to test new tools for differentiating essential tremor from dystonic tremor. To that aim, we propose a number of temporal and spectral features that are calculated from measured gyroscope signals, and identify those that provide optimal differentiation between two groups. The mean signal amplitude feature results in sensitivity = 0.8537 and specificity = 0.8039 in distinguishing patients having cervical dystonia with or without tremor. In addition, mean signal amplitude was shown to be significantly higher in patients with essential tremor than in patients with cervical dystonia, whereas the mean peak frequency is not different between two groups.

Origin of Shallow Volcanic Tremor: The Dynamics of Gas Pockets Trapped Beneath Thin Permeable Media

AbstractLinking volcano‐seismic signals with subsurface processes is crucial to improve the forecasting of volcanic eruptions. One of the most enigmatic signals is shallow volcanic tremor, a highly periodic ground vibration that is typically sourced beneath the crater of active volcanoes, is long lasting (from minutes to years), appears during unrest periods, and frequently precedes eruptions. In this paper, we demonstrate that shallow tremor can be produced by periodic pressure oscillations emerging spontaneously beneath permeable media (e.g., fractured magma caps). These pressure oscillations are the result of three concurrent processes: (a) the transient porous flow of gases through the permeable cap; (b) the temporary accumulation of these gases beneath the cap, forming a gas pocket; and (c) the random supply of volatiles from deeper levels. For highly permeable media (≥10−12 m2; realistic for shallow volcanic edifices), the pressure in subsurface gas pockets is governed by the equation of a linear oscillator; hence, under proper conditions, periodic pressure oscillations emerge during the transfer of gases from the Earth's interior to the surface. Our model is consistent with geophysical data showing that the tremor source is localized at a fixed region and can explain the main characteristics of ground vibrations, including frequency gliding, variations of seismic amplitude prior to eruptions, and the different types of tremor observed. For thin permeable caps (<100 m), we find that different eruption mechanisms (e.g., magma ascent vs. cap sealing) leave distinct footprints in the tremor properties, thus opening new perspectives to forecast the type and style of impending eruptions.

Tremor: A Clinical Guide For The Non-Neurologist

Tremor is the commonest involuntary movement. The differential diagnosis is wide, and can be challenging even for experienced neurologists. Nonetheless, many tremors have a benign etiology and clinical course and, in many cases, non-neurologists are able to clinically manage these situations. This manuscript approaches the different types of tremor, their diagnosis, main differential diagnoses, the desired clinical approach, and therapeutic options of the most important conditions in clinical practice.

Cerebello-cortical network fingerprints differ between essential, Parkinson's and mimicked tremors.

Cerebello-thalamo-cortical loops play a major role in the emergence of pathological tremors and voluntary rhythmic movements. It is unclear whether these loops differ anatomically or functionally in different types of tremor. We compared age- and sex-matched groups of patients with Parkinson's disease or essential tremor and healthy controls (n = 34 per group). High-density 256-channel EEG and multi-channel EMG from extensor and flexor muscles of both wrists were recorded simultaneously while extending the hands against gravity with the forearms supported. Tremor was thereby recorded from patients, and voluntarily mimicked tremor was recorded from healthy controls. Tomographic maps of EEG-EMG coherence were constructed using a beamformer algorithm coherent source analysis. The direction and strength of information flow between different coherent sources were estimated using time-resolved partial-directed coherence analyses. Tremor severity and motor performance measures were correlated with connection strengths between coherent sources. The topography of oscillatory coherent sources in the cerebellum differed significantly among the three groups, but the cortical sources in the primary sensorimotor region and premotor cortex were not significantly different. The cerebellar and cortical source combinations matched well with known cerebello-thalamo-cortical connections derived from functional MRI resting state analyses according to the Buckner-atlas. The cerebellar sources for Parkinson's tremor and essential tremor mapped primarily to primary sensorimotor cortex, but the cerebellar source for mimicked tremor mapped primarily to premotor cortex. Time-resolved partial-directed coherence analyses revealed activity flow mainly from cerebellum to sensorimotor cortex in Parkinson's tremor and essential tremor and mainly from cerebral cortex to cerebellum in mimicked tremor. EMG oscillation flowed mainly to the cerebellum in mimicked tremor, but oscillation flowed mainly from the cerebellum to EMG in Parkinson's and essential tremor. The topography of cerebellar involvement differed among Parkinson's, essential and mimicked tremors, suggesting different cerebellar mechanisms in tremorogenesis. Indistinguishable areas of sensorimotor cortex and premotor cerebral cortex were involved in all three tremors. Information flow analyses suggest that sensory feedback and cortical efferent copy input to cerebellum are needed to produce mimicked tremor, but tremor in Parkinson's disease and essential tremor do not depend on these mechanisms. Despite the subtle differences in cerebellar source topography, we found no evidence that the cerebellum is the source of oscillation in essential tremor or that the cortico-bulbo-cerebello-thalamocortical loop plays different tremorogenic roles in Parkinson's and essential tremor. Additional studies are needed to decipher the seemingly subtle differences in cerebellocortical function in Parkinson's and essential tremors.

Tremor in progressive supranuclear palsy

IntroductionTremor is thought to be a rare feature of progressive supranuclear palsy (PSP). MethodsWe retrospectively reviewed the database of the CurePSP brain bank at Mayo Clinic Florida to retrieve all available clinical information for PSP patients. All patients underwent a standard neuropathological assessment and an immunohistochemical evaluation for tau and α-synuclein. DNA was genotyped for the MAPT H1/H2 haplotype. ResultsOf the 375 PSP patients identified, 344 had a documented presence or absence of tremor, which included 146 (42%) with tremor, including 29 (20%) with postural/action tremors, 16 (11%) with resting tremor, 7 (5%) with intention tremor, 20 (14%) with a combination of different types of tremor, and 74 (51%) patients who had tremor at some point during their illness, but details were unavailable. The tremor severity of 96% of the patients (54/55) who had this data was minimal to mild. The probability of observing a tremor during a neurological examination during the patient's illness was estimated to be ∼22%. PSP patients with postural/action tremors and PSP patients with resting tremor responded to carbidopa-levodopa therapy more frequently than PSP patients without tremor, although the therapy response was always transient. There were no significant differences in pathological findings between the tremor groups. ConclusionsTremor is an inconspicuous feature of PSP; however, 42% (146/344) of the PSP patients in our study presented some form of tremor. Because there is no curative therapy for PSP, carbidopa/levodopa therapy should be tried for patients with postural, action, and resting tremor.

Types of tremor in patients with cerebrovascular diseases and cardiovascular events

Introduction: Tremor can occur as a part of the clinical picture of cerebrovascular diseases. Many patients with cerebral stroke have cardiovascu- lar diseases as a comorbidity or complication of stroke; sometimes cardiovascular events can lead to embolic stroke. Aim: To present types of tremor in patients with cerebrovascular diseases and cardiovascular events and diabetes mellitus type 2, clinical characteristics of tremor and investigations used. Material and methods: In our study we included 36 patients, 24 men and 12 women, that were exami- ned and followed for 3 years, from 2012-2015. All pa- tients were subjected to the following investigations: neurological examination, laboratory analysis, compu- terized tomography of brain, magnetic resonance ima- ging and electroencephalography. In cardiovascular patients we also performed Doppler sonography of ca- rotid arteries, electrocardiography, cardiac ultrasound. The patients were examined and treated by cardiolo- gists. Results: Of all patients 22% had cerebral infarc- tion, 41% atherosclerosis, 36% multiple lacunar in- farctions and 28% diabetes mellitus type 2. Three pati- ents with cerebral infarction had chorea, hemiballi- smus, dystonia and dystonic tremor, three had postural tremor and two cerebellar intention tremor. Athero- sclerotic patients had atherosclerotic action tremor, while diabetic patients predominantly had with ac- tion-type tremor. Electroencephalography showed irri- tative basic brain activity with slow waves, while caro- tid arteries stenosis was diagnosed by Doppler sono- graphy. Computerized tomography of the brain and magnetic resonance imaging revealed cerebrovascular diseases in certain areas. Patients with cardiomyo- pathy, rhythm disorders, high blood pressure, hyperli- pidemia was investigated and medically treated by a cardiologist. Conclusion: In cerebrovascular diseases different types of tremor can occur as a result of damage of the extrapyramidal system.

Distinction between essential and physiological tremor using Hilbert-Huang transform

Neurophysiological investigation, based on accelerometric (ACC) and electromyographic (EMG) recordings, is an essential step in the diagnosis of tremor. Among various signal analysis methods, fast Fourier transform (FFT) is the most frequently used in this domain. However, FFT has several limitations: first, it assumes that tremor is a periodic and linear signal, which is not true; second, it cannot distinguish between different types of tremor, when their frequency overlap in similar range, such as essential tremor (ET) and physiological tremor (PT). Therefore, we decided to apply a non-linear method of signal analysis based on empirical mode decomposition (EMD) and Hilbert Huang transform (HHT), according to various procedures and compared to a more classical FFT approach. A first group of 8 healthy subjects with PT and a second group of 8patients with ET were included in this study. At individual level, FFT was effective to highlight ET in the 8patients, but PT in only 2subjects. The EMD-HHT procedures performed better than FFT, revealing a common peak of PT in all subjects. Moreover, at group level, our EMD-HHT method allowed to clearly differentiate the two groups, especially by giving evidence for the existence of low frequency oscillations (around 4Hz) in subjects with PT. Although their physiological origin remains largely unknown, such slow oscillations seem to be of great importance to highlight PT and they have been much underestimated in the literature. Our original EMD-HHT approach is able to provide substantial improvement in the neurophysiological characterisation of the different types of tremor, especially for diagnostic application.

Analysis of tremor in motor learning task

Abstract Hand-eye coordination is required in many skilled tasks. Individual differences affect the performance of people at work and leisure, for example, during assembly jobs or sports. The aim of this study was to determine whether motor learning can change the physiological action of hand tremor. Tremor is a repetitive and stereotyped movement, with regular frequency and amplitude, but there are different types of tremors with pattern variation. The results were calculated by participants’ time-on and time-off the target, the average distance from the center of the target, and the frequency of oscillatory movement of a cursor (tremor). The results of this study indicate a statistically significant (p<0.05) influence of effect of task repetition on improvement of motor control and reduction of a high-amplitude tremor and an increase of a low-amplitude tremor. The assessed individuals achieved more than 50% better outcomes of a hand-eye coordination task in the final trials when compared with the initial trials. The dynamics of motor learning tend to rise, with a steady level of a 1-h interval between trials.

Prevalence and clinical classification of tremor in elderly—A community‐based survey in Brazil

Prevalence data on different types of tremor among the elderly population are very scarce. The objective of this study was to study the prevalence of tremor in a community-dwelling elderly population in the town of Bambuí, Brazil. The authors studied 1186 inhabitants aged≥64 years. This was a 2-phase study in which all participants who screened positive in a questionnaire for tremor and parkinsonism or who used drugs capable of causing/suppressing tremor were examined. In this population, the prevalence rate was 17.4% for tremor, 7.4% for essential tremor, 5.6% for parkinsonian tremor, 2.8% for enhanced physiological tremor, and 1.6% for other causes. There were no gender differences in prevalence rates for all types. Patients who had Parkinson's disease with tremor were older than those who had essential tremor, whereas patients who had enhanced physiological tremor were significantly younger. The age-specific prevalence of tremor increased with advancing age for both men and women. The prevalence of tremor in the studied population was high and increased with advancing age. Essential tremor, parkinsonian tremor, and enhanced physiological tremor were the most commonly identified causes. © 2013 Movement Disorder Society.

A Multivariate Auto-Regressive Method to Estimate Cortico-Muscular Coherence for the Detection of Movement Intent

In this work a time-frequency approach to estimate the Cortico-Muscular Coherence for the detection of the movement intent is presented, assessed on simulated data, and evaluated experimentally during different motor tasks performed by healthy subjects and patients suffering from different types of tremor. Cortico-Muscular Coherence is an index of the coupling of EEG signal in the cortical area with sEMG activity in the frequency domain, and its contributions in the beta band (15–30 Hz) have been associated to the movement intent. Cortico-Muscular Coherence estimation is here achieved by considering a closed-loop representation of the signals under analysis obtained through Multivariate Auto Regressive modeling. Significance levels for Cortico-Muscular Coherence are assessed by means of a surrogate data analysis approach. The detection technique is able to reveal significant Cortico-Muscular Coherence changes in 79% of the experimental trials, with a mean anticipation of 1.35 s with respect to movement onset. Time-frequency estimation of Cortico-Muscular Coherence can provide an insight for the development of a multimodal BCI able to integrate information from the brain activity in the functioning of assistive devices.

Günther Deuschl: from mathematics to movement disorders

Günther Deuschl: from mathematics to movement disorders

P23-4 Surface electromyographic characteristics of different types of tremors

P23-4 Surface electromyographic characteristics of different types of tremors

Telemonitoring System of Neurological Signs in a Health Telematique Network

The paper presents a new, experimental, wireless tremor telemonitoring system composed of an optional variable number of portable devices integrating three-axis acceleration mini-sensors which are connected to very small dimensions acquisition systems with Wi-Fi transmission capabilities. The main advantages of the design system consist of the possibilities to monitor simultaneously many body parts of one or multiple subjects on local or more extended areas both for scheduled assessments and in an everyday life environment. Possible applications of the presented experimental system, considered as a part of a health telematic network, consist of delivering supplementary, consistent sets of data to clinicians in order to reliably assess patients’ state in home and community settings, over longer periods of time. This system consists of delivering new data necessary for differential diagnosis of different types of tremors, or to precise different stages of illness in a health telematic network. The multiple simultaneous measuring capabilities and the extended observation time period could cover eventually neglected aspects related to occasional, temporary, or an intermittent tremor. The Wi-Fi DAQ proposed system’s novelty, in contrast with existing Wi-Fi solutions, is its ultra low power Wi-Fi capability, which makes it suitable for sensing applications where battery power management is critical.

Functional imaging of tremor.

We review the insight that has been obtained from positron emission tomography (PET) and magnetic resonance imaging (MRI) activation studies on the functional anatomy underlying different forms of tremor. The effects of treatment, both pharmacologic and interventional approaches, on the dysfunctional cerebral systems involved in tremor, also are considered. Finally, we speculate on the neuropharmacologic basis of different types of tremor based on available in vivo PET evidence.

P234 Monitoring of drug efficacy on different types of tremor in Parkinson's disease

P234 Monitoring of drug efficacy on different types of tremor in Parkinson's disease

Epilepsia partialis continua: semiology and differential diagnoses

Epilepsia partialis continua (EPC) is a rare form of focal status epilepticus. It may have vascular, immune-mediated, neoplastic or metabolic-toxic causes. The origin of EPC has been linked with the motor cortex. This has been solidly supported by sophisticated electrophysiological studies. Here, a series of video sequences from patients with EPC (due to Rasmussen encephalitis, early-stage multiple sclerosis, and steroid responsive encephalopathy with autoimmune thyroiditis), and other cases with repetitive myoclonic jerks or movement disorders (myoclonic epilepsy associated with ragged-red fibers, Jacksonian march, myoclonic seizures in other types of frontal lobe or idiopathic generalized epilepsies, and different types of tremor) is presented. [Published with video sequences].

Effektive und sichere Therapie eines behindernden Tremors - Tiefe Hirnstimulation bei Tremor

Tremor kann bei verschiedenen neurologischen Erkrankungen auftreten und ist häufig durch medikamentöse Behandlung gut zu unterdrücken. Ein stark ausgeprägter Tremor, der häufig nicht auf Medikation anspricht, ist eine gute Indikation für die tiefe Hirnstimulation. Dieses Verfahren ist aus dem experimentellen Stadium herausgetreten und hat sich in den letzten 10 Jahren als effektive und sichere Therapie eines behindernden Tremors etabliert. Es basiert auf der Implantation von Elektroden in verschiedene Zentren des Gehirnes, die dort verbleiben und über subkutane Impulsgeber dauernd gereizt werden. Die verschiedenen Tremorarten werden im Folgenden aufgeführt und besprochen, wie die Indikation zur Hirnstimulation jeweils zu stellen ist.