Impact of Covid-19 on essential tremor and dystonic tremor: Experience of an Italian centre

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.

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A Tremor with an Abnormal Posture

10.1093/med/9780190607555.003.0018 ◽

2016 ◽

Author(s):

Robertus M. A. de Bie ◽

Susanne E. M. Ten Holter

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Deep Brain Stimulation ◽

Essential Tremor ◽

Brain Stimulation ◽

Movement Disorders ◽

Beta Blockers ◽

Dystonic Tremor ◽

Abnormal Posture ◽

Deep Brain

Dystonic tremors are a commonly misdiagnosed group of primary tremor disorders, typically mistaken for Parkinson’s disease or essential tremor. Like most movement disorders, this is a clinical diagnosis, so the overlap in some features between all of these disorders can be confusing to less experienced and even more experienced physicians. A tremor in the presence of a dystonia is a dystonic tremor syndrome, regardless of the clinical features. Treatment of dystonic tremor can be challenging without the same gratifying response seen to levodopa in tremor associated with Parkinson’s disease or to beta-blockers and primidone in essential tremor. Deep-brain stimulation remains an option in the most disabling cases.

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Tremors

10.2310/im.6352 ◽

2016 ◽

Author(s):

Alfonso Fasano ◽

Günther Deuschl

Keyword(s):

Movement Disorder ◽

Essential Tremor ◽

Involuntary Movement ◽

The Body ◽

Drug Induced ◽

Parkinsonian Tremor ◽

Dystonic Tremor ◽

Physiologic Tremor ◽

Disease Definition ◽

Holmes Tremor

Tremor is the most common movement disorder and denotes a rhythmic and involuntary movement of one or several regions of the body. This review covers disease definition, essential tremor, enhanced physiologic tremor, parkinsonian tremor, dystonic tremor, orthostatic tremor, cerebellar tremor, Holmes tremor, neuropathic tremor, palatal tremor, drug-induced and toxic tremors, functional tremor, rare tremor syndromes, tremorlike conditions, and treatment of tremor. Figures show action tremor assessment, the central nervous system circuits of tremor, magnetic resonance imaging findings in specific tremor conditions, general management of tremor patients, an algorithm for the treatment of parkinsonian tremor, and an algorithm for the treatment of dystonic tremor and primary writing tremor. Tables list types of tremor according to the condition of activation, tremor conditions in newborns and during childhood, clinical features of the most common tremor syndromes, motor signs other than tremor and nonmotor features of essential tremor patients, Movement Disorder Society consensus criteria for the diagnosis of essential tremor, genetic and environmental causes of essential tremor, causes of enhanced physiologic tremor, drugs and toxins known to cause tremor, paroxysmal tremors, pseudorhythmic myoclonus in the differential diagnosis of tremor, and pharmacologic management of essential tremor. Key words: essential tremor, movement disorder, pathologic tremor, physiologic tremor, tremor This review contains 6 highly rendered figures, 7 videos, 11 tables, and 163 references.

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Unusual Forehead Tremor in Four Patients with Essential Tremor

Case Reports in Neurological Medicine ◽

10.1155/2012/278140 ◽

2012 ◽

Vol 2012 ◽

pp. 1-3

Author(s):

Jordi Gascón-Bayarri ◽

Jaume Campdelacreu ◽

Màtil Calopa ◽

Serge Jaumà ◽

Laura Bau ◽

...

Keyword(s):

Botulinum Toxin ◽

Essential Tremor ◽

The Other ◽

Dystonic Tremor ◽

Unilateral Involvement

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.

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Comparative connectivity correlates of dystonic and essential tremor deep brain stimulation

Brain ◽

10.1093/brain/awab074 ◽

2021 ◽

Author(s):

Takashi Tsuboi ◽

Joshua K Wong ◽

Robert S Eisinger ◽

Lela Okromelidze ◽

Mathew R Burns ◽

...

Keyword(s):

Deep Brain Stimulation ◽

Essential Tremor ◽

Brain Stimulation ◽

Rating Scale ◽

Structural Connectivity ◽

Cortical Network ◽

Dystonic Tremor ◽

Intermediate Nucleus ◽

Ventral Intermediate Nucleus ◽

Deep Brain

Abstract The pathophysiology of dystonic tremor and essential tremor remains partially understood. In patients with medication-refractory dystonic tremor or essential tremor, deep brain stimulation (DBS) targeting the thalamus or posterior subthalamic area has evolved into a promising treatment option. However, the optimal DBS targets for these disorders remains unknown. This retrospective study explored the optimal targets for DBS in essential tremor and dystonic tremor using a combination of volumes of tissue activated estimation and functional and structural connectivity analyses. We included 20 patients with dystonic tremor who underwent unilateral thalamic DBS, along with a matched cohort of 20 patients with essential tremor DBS. Tremor severity was assessed preoperatively and approximately 6 months after DBS implantation using the Fahn-Tolosa-Marin Tremor Rating Scale. The tremor-suppressing effects of DBS were estimated using the percentage improvement in the unilateral tremor-rating scale score contralateral to the side of implantation. The optimal stimulation region, based on the cluster centre of gravity for peak contralateral motor score improvement, for essential tremor was located in the ventral intermediate nucleus region and for dystonic tremor in the ventralis oralis posterior nucleus region along the ventral intermediate nucleus/ventralis oralis posterior nucleus border (4 mm anterior and 3 mm superior to that for essential tremor). Both disorders showed similar functional connectivity patterns: a positive correlation between tremor improvement and involvement of the primary sensorimotor, secondary motor and associative prefrontal regions. Tremor improvement, however, was tightly correlated with the primary sensorimotor regions in essential tremor, whereas in dystonic tremor, the correlation was tighter with the premotor and prefrontal regions. The dentato-rubro-thalamic tract, comprising the decussating and non-decussating fibres, significantly correlated with tremor improvement in both dystonic and essential tremor. In contrast, the pallidothalamic tracts, which primarily project to the ventralis oralis posterior nucleus region, significantly correlated with tremor improvement only in dystonic tremor. Our findings support the hypothesis that the pathophysiology underpinning dystonic tremor involves both the cerebello-thalamo-cortical network and the basal ganglia-thalamo-cortical network. Further our data suggest that the pathophysiology of essential tremor is primarily attributable to the abnormalities within the cerebello-thalamo-cortical network. We conclude that the ventral intermediate nucleus/ventralis oralis posterior nucleus border and ventral intermediate nucleus region may be a reasonable DBS target for patients with medication-refractory dystonic tremor and essential tremor, respectively. Uncovering the pathophysiology of these disorders may in the future aid in further improving DBS outcomes.

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Review: Diagnosis and management of essential tremor and dystonic tremor

Therapeutic Advances in Neurological Disorders ◽

10.1177/1756285609104791 ◽

2009 ◽

Vol 2 (4) ◽

pp. 215-222 ◽

Cited By ~ 21

Author(s):

Alexandre Gironell ◽

Jaime Kulisevsky

Keyword(s):

Essential Tremor ◽

Diagnosis And Management ◽

Dystonic Tremor

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Network-level connectivity is a critical feature distinguishing dystonic tremor and essential tremor

Brain ◽

10.1093/brain/awz085 ◽

2019 ◽

Vol 142 (6) ◽

pp. 1644-1659 ◽

Cited By ~ 16

Author(s):

Jesse C DeSimone ◽

Derek B Archer ◽

David E Vaillancourt ◽

Aparna Wagle Shukla

Keyword(s):

Functional Connectivity ◽

Essential Tremor ◽

Clinical Features ◽

Visual Feedback ◽

Grip Force ◽

Precision Grip ◽

Critical Feature ◽

Dystonic Tremor ◽

Body Regions ◽

Force Tremor

AbstractDystonia is a movement disorder characterized by involuntary muscle co-contractions that give rise to disabling movements and postures. A recent expert consensus labelled the incidence of tremor as a core feature of dystonia that can affect body regions both symptomatic and asymptomatic to dystonic features. We are only beginning to understand the neural network-level signatures that relate to clinical features of dystonic tremor. At the same time, clinical features of dystonic tremor can resemble that of essential tremor and present a diagnostic confound for clinicians. Here, we examined network-level functional activation and connectivity in patients with dystonic tremor and essential tremor. The dystonic tremor group included primarily cervical dystonia patients with dystonic head tremor and the majority had additional upper-limb tremor. The experimental paradigm included a precision grip-force task wherein online visual feedback related to force was manipulated across high and low spatial feedback levels. Prior work using this paradigm in essential tremor patients produced exacerbation of grip-force tremor and associated changes in functional activation. As such, we directly compared the effect of visual feedback on grip-force tremor and associated functional network-level activation and connectivity between dystonic tremor and essential tremor patient cohorts to better understand disease-specific mechanisms. Increased visual feedback similarly exacerbated force tremor during the grip-force task in dystonic tremor and essential tremor cohorts. Patients with dystonic tremor and essential tremor were characterized by distinct functional activation abnormalities in cortical regions but not in the cerebellum. We examined seed-based functional connectivity from the sensorimotor cortex, globus pallidus internus, ventral intermediate thalamic nucleus, and dentate nucleus, and observed abnormal functional connectivity networks in dystonic tremor and essential tremor groups relative to controls. However, the effects were far more widespread in the dystonic tremor group as changes in functional connectivity were revealed across cortical, subcortical, and cerebellar regions independent of the seed location. A unique pattern for dystonic tremor included widespread reductions in functional connectivity compared to essential tremor within higher-level cortical, basal ganglia, and cerebellar regions. Importantly, a receiver operating characteristic determined that functional connectivity z-scores were able to classify dystonic tremor and essential tremor with 89% area under the curve, whereas combining functional connectivity with force tremor yielded 94%. These findings point to network-level connectivity as an important feature that differs substantially between dystonic tremor and essential tremor and should be further explored in implementing appropriate diagnostic and therapeutic strategies.

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Thalamic deep brain stimulation for tremor in Parkinson disease, essential tremor, and dystonia

Neurology ◽

10.1212/wnl.0000000000004295 ◽

2017 ◽

Vol 89 (13) ◽

pp. 1416-1423 ◽

Cited By ~ 79

Author(s):

Rubens Gisbert Cury ◽

Valerie Fraix ◽

Anna Castrioto ◽

Maricely Ambar Pérez Fernández ◽

Paul Krack ◽

...

Keyword(s):

Deep Brain Stimulation ◽

Parkinson Disease ◽

Essential Tremor ◽

Brain Stimulation ◽

Rating Scale ◽

Dystonic Tremor ◽

Over Time ◽

Deep Brain

Objective:To report on the long-term outcomes of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) in Parkinson disease (PD), essential tremor (ET), and dystonic tremor.Methods:One hundred fifty-nine patients with PD, ET, and dystonia underwent VIM DBS due to refractory tremor at the Grenoble University Hospital. The primary outcome was a change in the tremor scores at 1 year after surgery and at the latest follow-up (21 years). Secondary outcomes included the relationship between tremor score reduction over time and the active contact position. Tremor scores (Unified Parkinson's Disease Rating Scale-III, items 20 and 21; Fahn, Tolosa, Marin Tremor Rating Scale) and the coordinates of the active contacts were recorded.Results:Ninety-eight patients were included. Patients with PD and ET had sustained improvement in tremor with VIM stimulation (mean improvement, 70% and 66% at 1 year; 63% and 48% beyond 10 years, respectively; p < 0.05). There was no significant loss of stimulation benefit over time (p > 0.05). Patients with dystonia exhibited a moderate response at 1-year follow-up (41% tremor improvement, p = 0.027), which was not sustained after 5 years (30% improvement, p = 0.109). The more dorsal active contacts' coordinates in the right lead were related to a better outcome 1 year after surgery (p = 0.029). During the whole follow-up, forty-eight patients (49%) experienced minor side effects, whereas 2 (2.0%) had serious events (brain hemorrhage and infection).Conclusions:VIM DBS is an effective long-term (beyond 10 years) treatment for tremor in PD and ET. Effects on dystonic tremor were modest and transient.Classification of evidence:This provides Class IV evidence. It is an observational study.

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038 Tremor: a clinical and neurophysiological study

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2019-anzan.35 ◽

2019 ◽

Vol 90 (e7) ◽

pp. A13.2-A13

Author(s):

Alessandro Fois ◽

Neil Mahant ◽

Steve Vucic ◽

Victor SC Fung

Keyword(s):

Essential Tremor ◽

Upper Limb ◽

Temporal Discrimination ◽

Clinical Trial Design ◽

Clinical Problem ◽

Future Research ◽

Cross Sectional ◽

Clinical Criteria ◽

Dystonic Tremor ◽

Neurophysiological Studies

IntroductionTremor is a common clinical problem seen in a number of diseases. Robust classification and diagnosis of tremor remains controversial due to overlap in clinical features and lack of established biomarkers. This hampers effective research including therapeutic trials. We present our research protocol for a cross-sectional study which aims to find more robust methods of tremor classification and diagnosis.MethodsAdults with upper limb tremor of varying aetiologies, diagnosed using current clinical criteria (including essential tremor, Parkinsonian tremor, and dystonic tremor), and age-matched controls are eligible for recruitment. Participants undergo a clinical and neurophysiological assessment, including accelerometry, surface electromyography, long-latency stretch reflexes, temporal discrimination, and tonic vibration reflexes. Data will be analysed using a cluster analysis to identify robust tremor syndromes and biomarkers associated with them. We aim to recruit 100 participants prior to analysis.ResultsAt time of writing, 13 participants with upper limb tremor have been studied (6 with essential tremor, 5 with dystonic tremor, and 2 with indeterminate tremor; mean age 66 years, range 18–85). Participants tolerated the clinical and neurophysiological studies well with 100% completion rate after recruitment. With current rates of recruitment we anticipate completion of recruitment and commencement of data analysis in October 2019.ConclusionsOur protocol aims to identify robust tremor phenotypes and biomarkers for them. This will allow patients with tremor to be classified into more biologically homogeneous diagnostic categories, aiding future research into the mechanism of tremor and more rational clinical trial design.

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