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Louis ED. Six Myths and Misconceptions about Essential Tremor. Tremor Other Hyperkinet Mov (N Y) 2024; 14:49. [PMID: 39346807 PMCID: PMC11428667 DOI: 10.5334/tohm.948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2024] [Accepted: 09/16/2024] [Indexed: 10/01/2024] Open
Abstract
There are myths and misperceptions about most human diseases, and neurological diseases are no exception. In many instances, myths and misconceptions reflect what is no more than the collective failure of the field to catch up with the state of the science in that field. Hence, one may perhaps refer to these as "lags" rather than myths. As the field of medicine attempts to be evidence-based, it is best to remain true to published data and the state of the science. In this paper, I review six myths and misconceptions about ET. Myth 1 relates to the natural history and prognosis of ET. Myths 2 and 3 relate to the biological basis of ET, whereas myths 4 and 5 relate to the expression of the core clinical feature of ET. Finally, myth 6 focuses on the issue of disease classification. The myths are as follows: Myth 1: "ET is not associated with a shorter life expectancy". Myth 2: "The pathophysiology of ET remains unclear". Myth 3: "There have also been studies that do not show any cerebellar degeneration". Myth 4: "ET is a postural or a kinetic tremor". Myth 5: "Action tremor in ET is usually bilateral and symmetric". Myth 6: "ET plus". As neurologists, we are not ignorant of feedback loops. A regular review of facts should help to frame one's output. As such, one's formulations and output will be firmly grounded in data.
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Affiliation(s)
- Elan D. Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Andrews L, Keller S, Ratcliffe C, Osman-Farah J, Shepherd H, Bhojak M, Macerollo A. Exploring White Matter Microstructure with Symptom Severity and Outcomes Following Deep Brain Stimulation in Tremor Syndromes. Tremor Other Hyperkinet Mov (N Y) 2024; 14:43. [PMID: 39220675 PMCID: PMC11363889 DOI: 10.5334/tohm.904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 09/04/2024] Open
Abstract
Background Essential tremor (ET) and dystonic tremor (DT) are movement disorders that cause debilitating symptoms, significantly impacting daily activities and quality of life. A poor understanding of their pathophysiology, as well as the mediators of clinical outcomes following deep brain stimulation (DBS), highlights the need for biomarkers to accurately characterise and optimally treat patients. Objectives We assessed the white matter microstructure of pathways implicated in the pathophysiology and therapeutic intervention in a retrospective cohort of patients with DT (n = 17) and ET (n = 19). We aimed to identity associations between white matter microstructure, upper limb tremor severity, and tremor improvement following DBS. Methods A fixel-based analysis pipeline was implemented to investigate white matter microstructural metrics in the whole brain, cerebello-thalamic pathways and tracts connected to stimulation volumes following DBS. Associations with preoperative and postoperative severity were analysed within each disorder group and across combined disorder groups. Results DBS led to significant improvements in both groups. No group differences in stimulation positions were identified. When white matter microstructural data was aligned according to the maximally affected upper limb, increased fiber density, and combined fiber density & cross-section of fixels in the left cerebellum were associated with greater tremor severity across DT and ET patients. White matter microstructure did not show associations with postoperative changes in cerebello-thalamic pathways, or tracts connected to stimulation volumes. Discussion Diffusion changes of the cerebellum are associated with the severity of upper limb tremor and appear to overlap in essential or dystonic tremor disorders.
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Affiliation(s)
- Luke Andrews
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
| | - Simon Keller
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
| | - Corey Ratcliffe
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
| | - Jibril Osman-Farah
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Hilary Shepherd
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Maneesh Bhojak
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Antonella Macerollo
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
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Angelini L, Paparella G, Cannavacciuolo A, Costa D, Birreci D, De Riggi M, Passaretti M, Colella D, Guerra A, Berardelli A, Bologna M. Clinical and kinematic characterization of parkinsonian soft signs in essential tremor. J Neural Transm (Vienna) 2024; 131:941-952. [PMID: 38744708 PMCID: PMC11343963 DOI: 10.1007/s00702-024-02784-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/06/2024] [Indexed: 05/16/2024]
Abstract
BACKGROUND Subtle parkinsonian signs, i.e., rest tremor and bradykinesia, are considered soft signs for defining essential tremor (ET) plus. OBJECTIVES Our study aimed to further characterize subtle parkinsonian signs in a relatively large sample of ET patients from a clinical and neurophysiological perspective. METHODS We employed clinical scales and kinematic techniques to assess a sample of 82 ET patients. Eighty healthy controls matched for gender and age were also included. The primary focus of our study was to conduct a comparative analysis of ET patients (without any soft signs) and ET-plus patients with rest tremor and/or bradykinesia. Additionally, we investigated the asymmetry and side concordance of these soft signs. RESULTS In ET-plus patients with parkinsonian soft signs (56.10% of the sample), rest tremor was clinically observed in 41.30% of cases, bradykinesia in 30.43%, and rest tremor plus bradykinesia in 28.26%. Patients with rest tremor had more severe and widespread action tremor than other patients. Furthermore, we observed a positive correlation between the amplitude of action and rest tremor. Most ET-plus patients had an asymmetry of rest tremor and bradykinesia. There was no side concordance between these soft signs, as confirmed through both clinical examination and kinematic evaluation. CONCLUSIONS Rest tremor and bradykinesia are frequently observed in ET and are often asymmetric but not concordant. Our findings provide a better insight into the phenomenology of ET and suggest that the parkinsonian soft signs (rest tremor and bradykinesia) in ET-plus may originate from distinct pathophysiological mechanisms.
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Affiliation(s)
- Luca Angelini
- IRCCS Neuromed, Via Atinense, 18, Pozzilli (IS), 86077, Italy
| | - Giulia Paparella
- IRCCS Neuromed, Via Atinense, 18, Pozzilli (IS), 86077, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | | | - Davide Costa
- IRCCS Neuromed, Via Atinense, 18, Pozzilli (IS), 86077, Italy
| | - Daniele Birreci
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | - Martina De Riggi
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | - Massimiliano Passaretti
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | - Donato Colella
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | - Andrea Guerra
- Parkinson and Movement Disorders Unit, Study Center on Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Padua, Italy
- Padova Neuroscience Center (PNC), University of Padua, Padua, Italy
| | - Alfredo Berardelli
- IRCCS Neuromed, Via Atinense, 18, Pozzilli (IS), 86077, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy
| | - Matteo Bologna
- IRCCS Neuromed, Via Atinense, 18, Pozzilli (IS), 86077, Italy.
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, Rome, 00185, Italy.
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Panyakaew P, Phuenpathom W, Bhidayasiri R, Hallett M. Bedside clinical assessment of patients with common upper limb tremor and algorithmic approach. ASIAN BIOMED 2024; 18:37-52. [PMID: 38708334 PMCID: PMC11063083 DOI: 10.2478/abm-2024-0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
The diagnostic approach for patients with tremor is challenging due to the complex and overlapping phenotypes among tremor syndromes. The first step in the evaluation of tremor is to identify the tremulous movement and exclude the tremor mimics. The second step is to classify the tremor syndrome based on the characteristics of tremor from historical clues and focused examination (Axis 1). Comprehensive tremor examinations involve the assessment of tremor in different conditions (rest, action or mixed, position or task-specific), distribution of tremor (upper limb, lower limb, head, jaw), positive signs for functional tremor (FT) if suspected (distractibility, entrainment, co-contraction), and associated neurological signs including parkinsonism, dystonic posture, cerebellar/brainstem signs, neuropathy, and cognitive impairment. A pivotal feature in this step is to determine any distinct feature of a specific isolated or combined tremor syndrome. In this review, we propose an algorithm to assess upper limb tremors. Ancillary testing should be performed if clinical evaluation is unclear. The choice of investigation depends on the types of tremors considered to narrow down the spectrum of etiology (Axis 2). Laboratory blood tests are considered for acute onset and acute worsening of tremors, while structural neuroimaging is indicated in unilateral tremors with acute onset, nonclassical presentations, and a combination of neurological symptoms. Neurophysiological study is an important tool that aids in distinguishing between tremor and myoclonus, etiology of tremor and document specific signs of FT. Treatment is mainly symptomatic based depending on the etiology of the tremor and the patient's disabilities.
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Affiliation(s)
- Pattamon Panyakaew
- Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok10330, Thailand
- Division of Neurology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok10330, Thailand
| | - Warongporn Phuenpathom
- Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok10330, Thailand
| | - Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok10330, Thailand
- Division of Neurology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok10330, Thailand
- The Academy of Science, The Royal Society of Thailand, Bangkok10330, Thailand
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892-1428, USA
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Pandey S, Dinesh S, Rawat CS, Thelma BK. The Spectrum of Non-Parkinsonian Tremor: A Registry at a Tertiary Care Teaching Institute. Tremor Other Hyperkinet Mov (N Y) 2023; 13:48. [PMID: 38145280 PMCID: PMC10742104 DOI: 10.5334/tohm.828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/09/2023] [Indexed: 12/26/2023] Open
Abstract
Background Tremors other than those associated with Parkinson's disease (non-parkinsonian tremor) are commonly observed in clinical settings. However, their frequency and clinical characteristics have rarely been reported. Objectives To classify non-parkinsonian tremors based on the consensus statement on the classification of tremors, from the task force of the International Parkinson and Movement Disorder Society published in 2018. Methods A prospective registry at a tertiary care teaching institute. Results A total of 475 patients with non-parkinsonian tremors were recruited for the study. 67.57% (n = 321) of our patients were male and a family history of tremor was present in 20.84% (n = 99) of patients. Dystonic tremor (DT) was the most common non-parkinsonian tremor (33.26%). 27.78% of patients fulfilled the new classification criteria for essential tremor, with 13.47% classified as pure ET (ET) and 14.31% exhibiting neurological soft signs, leading to the classification of ET plus (ETP). Patients with ETP had more family history (57.35%) [vs DT (26.48%, p = 0.00004) and ET (10.93%, p = 0.00003], longer duration of disease [mean ± standard deviation (SD) = 9.53 ± 8.64 years] [vs DT (5.60 ± 5.93, p = 0.0003) and ET (6.38 ± 5.97, p = 0.01) years], and more severe tremor as measured by the essential tremor rating assessment scale total score [mean ± SD = 27.42 ± 11.70] [vs DT (23.50 ± 8.62, p = 0.007) and ET (22.12 ± 8.19, p = 0.007)] compared with patients with DT and ET. Conclusions DT was the most common cause of non-parkinsonian tremor in our registry followed by essential tremor syndrome. ETP was more common than ET.
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Affiliation(s)
- Sanjay Pandey
- Department of Neurology, Govind Ballabh Pant Institute of Postgraduate medical education and Research, New Delhi, India
- Department of Neurology and Stroke Medicine, Amrita Hospital, Mata Amritanandamayi Marg Sector 88, Faridabad, Delhi National Capital Region, India
| | - Shreya Dinesh
- Department of Neurology, Govind Ballabh Pant Institute of Postgraduate medical education and Research, New Delhi, India
- Department of Microbiology and Bioinformatics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Chandra Shekhar Rawat
- Department of Neurology, Govind Ballabh Pant Institute of Postgraduate medical education and Research, New Delhi, India
| | - B K Thelma
- Department of Genetics, University of Delhi South Campus, New Delhi, India
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Albanese A. Clinical features of dystonia and the science of classification. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:1-20. [PMID: 37482389 DOI: 10.1016/bs.irn.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
This chapter describes advances in understanding the clinical features of dystonia since initial clinical recognition and its organization into a coherent and systematic clinical set. The clinical features of dystonia were at first considered an odd neurological movement disorder. Etymology of the word misleadingly underlined muscle tone. The main clinical features of dystonia were recognized gradually. They encompass dystonic movements, dystonic postures, alleviating maneuvers, overflow and mirroring. These features are observed in patients who present a variety of syndromes where dystonia occurs in isolation or combined with other movement disorders, or with other neurologic or systemic features. A large number of syndromic combinations is observed in the clinic and some of the syndomes are highlighted here. Practitioners are required to exert dedicated skills to recognize dystonia and correctly diagnose and classify their patients.
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Affiliation(s)
- Alberto Albanese
- Department of Neurology, IRCCS Humanitas Research Hospital, Milano, Italy; Department of Neuroscience, Catholic University, Milano, Italy.
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Lenka A, Pandey S. Dystonia and tremor: Do they have a shared biology? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:413-439. [PMID: 37482399 DOI: 10.1016/bs.irn.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Dystonia and tremor are the two most commonly encountered hyperkinetic movement disorders encountered in clinical practice. While there has been substantial progress in the research on these two disorders, there also exists a lot of gray areas. Entities such as dystonic tremor and tremor associated with dystonia occupy a major portion of the "gray zone". In addition, there is a marked clinical heterogeneity and overlap of several clinical and epidemiological features among dystonia and tremor. These facts raise the possibility that dystonia and tremor could be having shared biology. In this chapter, we revisit critical aspects of this possibility that may have important clinical and research implications in the future. We comprehensively review the points in favor and against the theory that dystonia and tremor have shared biology from clinical, epidemiological, genetic and neuroimaging studies.
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Affiliation(s)
- Abhishek Lenka
- Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX, United States
| | - Sanjay Pandey
- Department of Neurology, Amrita Hospital, Faridabad, Delhi National Capital Region, India.
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Angelini L, Paparella G, De Biase A, Maraone A, Panfili M, Berardelli I, Cannavacciuolo A, Di Vita A, Margiotta R, Fabbrini G, Berardelli A, Bologna M. Longitudinal study of clinical and neurophysiological features in essential tremor. Eur J Neurol 2023; 30:631-640. [PMID: 36437695 PMCID: PMC10107502 DOI: 10.1111/ene.15650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/15/2022] [Accepted: 11/21/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Essential tremor (ET) is a common and heterogeneous disorder characterized by postural/kinetic tremor of the upper limbs and other body segments and by non-motor symptoms, including cognitive and psychiatric abnormalities. Only a limited number of longitudinal studies have comprehensively and simultaneously investigated motor and non-motor symptom progression in ET. Possible soft signs that configure the ET-plus diagnosis are also under-investigated in follow-up studies. We aimed to longitudinally investigate the progression of ET manifestations by means of clinical and neurophysiological evaluation. METHODS Thirty-seven ET patients underwent evaluation at baseline (T0) and at follow-up (T1; mean interval ± SD = 39.89 ± 9.83 months). The assessment included the clinical and kinematic evaluation of tremor and voluntary movement execution, as well as the investigation of cognitive and psychiatric disorders. RESULTS A higher percentage of patients showed tremor in multiple body segments and rest tremor at T1 as compared to T0 (all p-values < 0.01). At T1, the kinematic analysis revealed reduced finger-tapping movement amplitude and velocity as compared to T0 (both p-values < 0.001). The prevalence of cognitive and psychiatric disorders did not change between T0 and T1. Female sex, absence of family history, and rest tremor at baseline were identified as predictive factors of worse disease progression. CONCLUSIONS ET progression is characterized by the spread of tremor in multiple body segments and by the emergence of soft signs. We also identified possible predictors of disease worsening. The results contribute to a better understanding of ET classification and pathophysiology.
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Affiliation(s)
- Luca Angelini
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | | | | | - Annalisa Maraone
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Matteo Panfili
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Isabella Berardelli
- Department of Neurosciences, Mental Health, and Sensory Organs, Suicide Prevention Center, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy
| | | | - Antonella Di Vita
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Roberta Margiotta
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Giovanni Fabbrini
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
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Louis ED. Essential tremor. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:389-401. [PMID: 37620080 DOI: 10.1016/b978-0-323-98817-9.00012-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Essential tremor (ET) is a chronic and progressive neurologic disease. Its central and defining clinical feature is a 4-12Hz kinetic tremor, that is, tremor that occurs during voluntary movements such as drinking from a cup or writing. Patients may also exhibit a range of other tremors-postural, rest, intention, additional motor features (e.g., mild gait ataxia, mild dystonia), as well as nonmotor features. The disease itself seems to be a risk factor for other degenerative diseases such as Alzheimer's disease and Parkinson's disease. Both genetic and toxic environmental factors have been explored as etiologic factors. In addition to a growing appreciation of the presence of clinical, etiologic, and pathologic heterogeneity, there is some support for the notion that ET itself may not be a single disease, but may be a family of diseases whose central defining feature is kinetic tremor of the arms, and which might more accurately be referred to as "the essential tremors." Recent research has increasingly placed the seat of the disease in the cerebellum and cerebellar system and identified a host of neurodegenerative changes within the cerebellum, indicating that this progressive disorder is likely degenerative.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
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Peterson A, Chapman S, Iglesias Hernandez D, Tafader M, Louis ED, Cosentino S. Motor features associated with cognition in non-demented individuals with essential tremor. J Neurol Sci 2022; 439:120323. [PMID: 35752130 PMCID: PMC9942278 DOI: 10.1016/j.jns.2022.120323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/13/2022] [Accepted: 06/12/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Essential tremor (ET) is a clinically heterogeneous disease characterized by motor and non-motor features, including cognitive impairment. In a cross-sectional analysis, we determined whether the presence and severity of motor features of ET are associated with cognitive performance. METHODS Participants enrolled in a study that used motor and neuropsychological measures to characterize a cohort of ET subjects. Action tremor severity and additional motor features (rest tremor, intention tremor, cranial tremor, dystonia, tandem gait missteps) were assessed in non-demented participants. Participants completed a cognitive test protocol assessing domains of memory, executive function, attention, visuospatial ability, and language. An average z-score was calculated to represent global cognition. RESULTS There were 204 ET participants (mean age 78.6, range 55-95). Participants with 10 missteps were more likely to have MCI than those with 0 or 1 misstep (p < 0.001). In unadjusted linear regression models, action tremor severity (p = 0.010), rest tremor (p < 0.001), and tandem gait missteps (p < 0.001) were negatively associated with global cognition. In adjusted models, only tandem gait missteps were negatively associated with global cognition (p < 0.001). Missteps were also negatively associated with memory (p < 0.001), executive function (p < 0.001), attention (p = 0.011), and visuospatial function (p = 0.043). No other motor features were associated with global cognition in adjusted models (p > 0.05). CONCLUSION Among non-demented participants with ET, there is an association between cognitive performance and tandem gait missteps, but no other motor features of ET. This is a first step in establishing impaired tandem gait as a possible indicator of cognitive impairment in patients with ET.
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Affiliation(s)
- Amalia Peterson
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Silvia Chapman
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | | | - Marjana Tafader
- Department of Neuroscience, Lafayette College, Easton, PA, USA
| | - Elan D. Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Stephanie Cosentino
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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Gauthier-Lafreniere E, Aljassar M, Rymar VV, Milton J, Sadikot AF. A standardized accelerometry method for characterizing tremor: Application and validation in an ageing population with postural and action tremor. Front Neuroinform 2022; 16:878279. [PMID: 35991289 PMCID: PMC9386269 DOI: 10.3389/fninf.2022.878279] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/28/2022] [Indexed: 02/06/2023] Open
Abstract
Background Ordinal scales based on qualitative observation are the mainstay in the clinical assessment of tremor, but are limited by inter-rater reliability, measurement precision, range, and ceiling effects. Quantitative tremor evaluation is well-developed in research, but clinical application has lagged, in part due to cumbersome mathematical application and lack of established standards. Objectives To develop a novel method for evaluating tremor that integrates a standardized clinical exam, wrist-watch accelerometers, and a software framework for data analysis that does not require advanced mathematical or computing skills. The utility of the method was tested in a sequential cohort of patients with predominant postural and action tremor presenting to a specialized surgical clinic with the presumptive diagnosis of Essential Tremor (ET). Methods Wristwatch accelerometry was integrated with a standardized clinical exam. A MATLAB application was developed for automated data analysis and graphical representation of tremor. Measures from the power spectrum of acceleration of tremor in different upper limb postures were derived in 25 consecutive patients. The linear results from accelerometry were correlated with the commonly used non-linear Clinical Rating Scale for Tremor (CRST). Results The acceleration power spectrum was reliably produced in all consecutive patients. Tremor frequency was stable in different postures and across patients. Both total and peak power of acceleration during postural conditions correlated well with the CRST. The standardized clinical examination with integrated accelerometry measures was therefore effective at characterizing tremor in a population with predominant postural and action tremor. The protocol is also illustrated on repeated measures in an ET patient who underwent Magnetic Resonance-Guided Focused Ultrasound thalamotomy. Conclusion Quantitative assessment of tremor as a continuous variable using wristwatch accelerometry is readily applicable as a clinical tool when integrated with a standardized clinical exam and a user-friendly software framework for analysis. The method is validated for patients with predominant postural and action tremor, and can be adopted for characterizing tremor of different etiologies with dissemination in a wide variety of clinical and research contexts in ageing populations.
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Affiliation(s)
- Etienne Gauthier-Lafreniere
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Health Centre, McGill University, Montreal, QC, Canada
- Department of Psychiatry, Montreal Neurological Institute, McGill University Health Centre, McGill University, Montreal, QC, Canada
| | - Meshal Aljassar
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Health Centre, McGill University, Montreal, QC, Canada
| | - Vladimir V. Rymar
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Health Centre, McGill University, Montreal, QC, Canada
| | - John Milton
- W.M. Keck Science Department, Claremont Colleges, Claremont, CA, United States
| | - Abbas F. Sadikot
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Health Centre, McGill University, Montreal, QC, Canada
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The differences in clinical characteristics and natural history between essential tremor and essential tremor plus. Sci Rep 2022; 12:7669. [PMID: 35538158 PMCID: PMC9091254 DOI: 10.1038/s41598-022-11775-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/29/2022] [Indexed: 11/08/2022] Open
Abstract
The diverse clinical manifestation of essential tremor (ET) has led to the question whether the different phenotypes may affect the clinical outcome and progression. This study aimed to estimate the clinical characteristics and natural history of ET and ET-plus. A total of 221 patients with ET were included, 117 (52.9%) reclassified as ET and 104 (47.1%) as ET-plus. Patients with ET-plus were significantly older in age at onset (P < 0.001); had a higher frequency of cranial tremors (P < 0.001), neurological comorbidities (P < 0.001) and psychiatric comorbidities (P = 0.025); more tremor progression (P < 0.001); and poorer response to medical treatment (P < 0.001) compared to ET patients. Regression analysis revealed that late-onset tremor (OR 11.02, 95% CI 2.79–43.53), neurological comorbidities (OR 3.38, 95% CI 1.56–7.31), psychiatric comorbidities (OR 4.29, 95% CI 1.48–12.44), cranial tremors (OR 2.10, 95% CI 1.02–4.30), and poor response to medical treatment (OR 3.67, 95% CI 1.87–7.19) were associated with ET-plus diagnosis. ET and ET-plus differ in the age of onset, tremor distribution, comorbidities, treatment response rate, and progression. Identifying the ET phenotypes may increase the clinical value in therapeutic strategies and clinical research in the future.
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Nieuwhof F, Toni I, Buijink AW, van Rootselaar AF, van de Warrenburg BP, Helmich RC. Phase-locked transcranial electrical brain stimulation for tremor suppression in dystonic tremor syndromes. Clin Neurophysiol 2022; 140:239-250. [DOI: 10.1016/j.clinph.2022.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/19/2022]
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14
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Pandey S. Is essential tremor a family of diseases or a syndrome? A syndrome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:31-59. [PMID: 35750367 DOI: 10.1016/bs.irn.2022.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In a consensus statement, a task force of the "International Parkinson and Movement Disorder Society" (IPMDS) has recently proposed a two axes classification for tremor: axis I (clinical manifestations) and axis II (etiology). In the axis, I, the clinical features of tremor in a given patient are specified in terms of medical history, tremor characteristics, associated signs, and laboratory tests for some tremors leading to the discovery of axis 2 etiologies. Based on axis I sign and symptoms a specific clinical syndrome is diagnosed which have been categorized as isolated tremor syndrome (a syndrome consisting only of tremor) and combined tremor syndrome (consisting of tremor and other systemic or neurological signs). The IPMDS task force defined essential tremor as an isolated tremor syndrome of bilateral upper limb action tremor of at least 3years duration with or without a tremor in other locations (e.g., head, voice or lower limbs) in absence of other neurological signs, such as dystonia, ataxia, or parkinsonism. Patients with neurological signs of uncertain significance (such as impaired tandem gait, questionable dystonic posturing, or memory impairment) are classified as essential tremor plus. In this paper, the author will make the argument that essential tremor is a syndrome with multiple causes.
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Affiliation(s)
- Sanjay Pandey
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, New Delhi, India.
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15
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Latorre A, Hallett M, Deuschl G, Bhatia KP. The MDS consensus tremor classification: The best way to classify patients with tremor at present. J Neurol Sci 2022; 435:120191. [PMID: 35247714 DOI: 10.1016/j.jns.2022.120191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/13/2022] [Accepted: 02/17/2022] [Indexed: 12/18/2022]
Abstract
In 2018, the new Consensus Statement on the Classification of Tremors, by the Task Force on Tremor of the International Parkinson Movement Disorder Society, was published. So far, the article has been cited more than 400 times in peer-reviewed international journals and commonly debated in conferences and meetings due to an enthusiastic welcome from the community. Compared to the previous Consensus Statement (1998), the main novelties are: 1) the classification of tremor according to clinical manifestation (Axis 1) and etiology (Axis 2), and therefore the use of a syndromic approach; 2) the definition of essential tremor as a syndrome; 3) the recognition of the new category essential tremor plus, that derives from the uncertain significance of the soft neurological signs often associated with essential tremor. In this paper, we summarise and explain the most important aspects of the new classification of tremors, highlighting the main novelties, their relevance, and application in clinical practice. Moreover, we discuss its possible weakness and reflect on the critical comments made so far. We believe that this new tremor classification is comprehensive, rigorous, and consistent and, considering our current knowledge of tremor syndromes, it is the best we can do at present. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Günther Deuschl
- Department of Neurology, UKSH, Christian-Albrechts-University, Kiel, Germany
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK.
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16
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Louis ED, Hernandez NC, Ottman R, Clark LN. Mixed Motor Disorder: Essential Tremor Families With Heterogeneous Motor Phenomenology. Neurol Clin Pract 2022; 11:e817-e825. [PMID: 34992964 DOI: 10.1212/cpj.0000000000001100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/09/2021] [Indexed: 11/15/2022]
Abstract
Background and Objectives Essential tremor (ET) is one of the most prevalent movement disorders. Because ET is so common, individuals with other neurologic disorders may also have ET. There is evidence, however, that the cooccurrence of ET with Parkinson disease (PD) and/or dystonia is not merely a chance cooccurrence. We have observed combinations of these 3 movement disorders within individuals and across individuals within families containing multiple individuals with ET. This observation has a number of implications. Our objective is to present 4 ET families in whom motor phenomenology was heterogeneous and discuss the implications of this finding. Methods ET cases and their relatives were enrolled in the Family Study of Essential Tremor (2015-present). Phenotyping was performed by a senior movement disorders neurologist based on neurologic examination. Results We present 4 families, including 14 affected individuals, among whom assigned diagnoses were ET, PD, ET + PD, and ET + dystonia. In those with ET and another movement disorder, the predominant and earliest phenotype was ET. Discussion There are assortments of these 3 involuntary motor disorders, ET, dystonia, and PD, both within individuals and in different individuals within ET families. This observation has mechanistic implications. Furthermore, we believe that the concept of the mixed motor disorder should enter into and inform the clinical dialogue. In assigning diagnoses, clinicians are swayed by family history information, and they should be prepared to observe a mix of different motor disorders to manifest within particular families.
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Affiliation(s)
- Elan D Louis
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Nora C Hernandez
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Ruth Ottman
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Lorraine N Clark
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
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17
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Elble RJ. Bayesian Interpretation of Essential Tremor Plus. J Clin Neurol 2022; 18:127-139. [PMID: 35274833 PMCID: PMC8926770 DOI: 10.3988/jcn.2022.18.2.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
Essential tremor (ET) plus is a new tremor classification that was introduced in 2018 by a task force of the International Parkinson and Movement Disorder Society. Patients with ET plus meet the criteria for ET but have one or more additional systemic or neurologic signs of uncertain significance or relevance to tremor (“soft signs”). Soft signs are not sufficient to diagnose another tremor syndrome or movement disorder, and soft signs in ET plus are known to have poor interrater reliability and low diagnostic sensitivity and specificity. Therefore, the clinical significance of ET plus must be interpreted probabilistically when judging whether a patient is more likely to have ET or a combined tremor syndrome, such as dystonic tremor. Such a probabilistic interpretation is possible with Bayesian analysis. This review presents a Bayesian analysis of ET plus in patients suspected of having ET versus a dystonic tremor syndrome, which is the most common differential diagnosis in patients referred for ET. Bayesian analysis of soft signs provides an estimate of the probability that a patient with possible ET is more likely to have an alternative diagnosis. ET plus is a distinct tremor classification and should not be viewed as a subtype of ET. ET plus covers a more-comprehensive phenotyping of people with possible ET, and the clinical interpretation of ET plus is enhanced with Bayesian analysis of associated soft signs.
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Affiliation(s)
- Rodger J. Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
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18
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Lenka A, Pandey S. Essential Tremor: Five New Things. Neurol Clin Pract 2021; 12:183-186. [PMID: 35747894 PMCID: PMC9208407 DOI: 10.1212/cpj.0000000000001145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 10/19/2021] [Indexed: 11/15/2022]
Abstract
ABSTRACTPurpose of the review:To highlight five new things in the research and clinical aspects of essential tremor (ET).Recent findings:The introduction of a new definition of ET and a new category “ET plus” were the major themes of the recent consensus statement. This new change demands a change in the approach to the clinical diagnosis of ET and related diseases. From the pathogenesis standpoint, the cerebellar neurodegenerative model seems to have numerous evidence in its favor compared to the olivary model which has largely fallen out of favor. From the standpoint of therapeutics, magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has enriched the therapeutic armamentarium.Summary:There has been considerable progress in the field of ET. We discuss five new things in this article which include- (i) new definition (ii) ET plus (iii) approach to the diagnosis of ET, (iv) cerebellar degeneration, and (v) MRgFUS thalamotomy.
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Affiliation(s)
- Abhishek Lenka
- MedStar Georgetown University Hospital (AL), Washington, DC; and G.B. Pant Institute of Postgraduate Medical Education and Research (SP), New Delhi, India
| | - Sanjay Pandey
- MedStar Georgetown University Hospital (AL), Washington, DC; and G.B. Pant Institute of Postgraduate Medical Education and Research (SP), New Delhi, India
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19
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Iglesias-Hernandez D, Delgado N, McGurn M, Huey ED, Cosentino S, Louis ED. "ET Plus": Instability of the Diagnosis During Prospective Longitudinal Follow-up of Essential Tremor Cases. Front Neurol 2021; 12:782694. [PMID: 34975736 PMCID: PMC8716461 DOI: 10.3389/fneur.2021.782694] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/26/2021] [Indexed: 11/13/2022] Open
Abstract
Background: A recent consensus statement introduced the term "ET plus". Although investigators have quantified the prevalence of ET plus in cross-sectional studies, patients with ET plus have not been tracked longitudinally; hence, there is no understanding of its stability over time. Methods: We present prospective, longitudinal phenotypic data on an ET cohort that was followed regularly at 18-month intervals (T1, T2, T3, T4) for up to 64 months. We assigned an ET or ET plus diagnosis to each case at each time interval. Results: There were 201 participants at baseline. The proportion with ET plus increased from 58.7% at baseline to 72.1% at T4 (p = 0.046). Of 172 (85.6%) who received a diagnosis of ET plus at one or more time intervals, the diagnosis was unstable (e.g., with reversion) in 62 (36.0%). We also assessed the stability of the clinical features of ET plus. Rest tremor was the most unstable clinical feature of ET plus; it was present in 59 participants, among whom it reverted from present to absent in 23 (39.0%). By contrast, for "memory impairment" (i.e., either mild cognitive impairment or dementia), the proportion who reverted from present to absent was only 21.3%. Conclusion: These data support our two a priori hypotheses: (1) the prevalence of ET plus would increase progressively, as it likely represents a more advanced stage of ET, and (2) the ET plus diagnosis would not be stable over time, as cases would fluctuate with respect to their phenotypic features and their assigned diagnoses.
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Affiliation(s)
| | - Nikki Delgado
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Margaret McGurn
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Edward D. Huey
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Stephanie Cosentino
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Elan D. Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States
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20
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Nieuwhof F, Toni I, Dirkx MF, Gallea C, Vidailhet M, Buijink AWG, van Rootselaar AF, van de Warrenburg BPC, Helmich RC. Cerebello-thalamic activity drives an abnormal motor network into dystonic tremor. Neuroimage Clin 2021; 33:102919. [PMID: 34929584 PMCID: PMC8688717 DOI: 10.1016/j.nicl.2021.102919] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 01/18/2023]
Abstract
Dystonic tremor syndromes are highly burdensome and treatment is often inadequate. This is partly due to poor understanding of the underlying pathophysiology. Several lines of research suggest involvement of the cerebello-thalamo-cortical circuit and the basal ganglia in dystonic tremor syndromes, but their role is unclear. Here we aimed to investigate the contribution of the cerebello-thalamo-cortical circuit and the basal ganglia to the pathophysiology of dystonic tremor syndrome, by directly linking tremor fluctuations to cerebral activity during scanning. In 27 patients with dystonic tremor syndrome (dystonic tremor: n = 23; tremor associated with dystonia: n = 4), we used concurrent accelerometery and functional MRI during a posture holding task that evoked tremor, alternated with rest. Using multiple regression analyses, we separated tremor-related activity from brain activity related to (voluntary) posture holding. Using dynamic causal modelling, we tested for altered effective connectivity between tremor-related brain regions as a function of tremor amplitude fluctuations. Finally, we compared grey matter volume between patients (n = 27) and matched controls (n = 27). We found tremor-related activity in sensorimotor regions of the bilateral cerebellum, contralateral posterior and anterior ventral lateral nuclei of the thalamus (VLp and VLa), contralateral primary motor cortex (hand area), contralateral pallidum, and the bilateral frontal cortex (laterality with respect to the tremor). Grey matter volume was increased in patients compared to controls in the portion of contralateral thalamus also showing tremor-related activity, as well as in bilateral medial and left lateral primary motor cortex, where no tremor-related activity was present. Effective connectivity analyses showed that inter-regional coupling in the cerebello-thalamic pathway, as well as the thalamic self-connection, were strengthened as a function of increasing tremor power. These findings indicate that the pathophysiology of dystonic tremor syndromes involves functional and structural changes in the cerebello-thalamo-cortical circuit and pallidum. Deficient input from the cerebellum towards the thalamo-cortical circuit, together with hypertrophy of the thalamus, may play a key role in the generation of dystonic tremor syndrome.
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Affiliation(s)
- Freek Nieuwhof
- Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6500 HB Nijmegen, the Netherlands
| | - Ivan Toni
- Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6500 HB Nijmegen, the Netherlands
| | - Michiel F Dirkx
- Department of Neurology, Centre of Expertise for Parkinson & Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands
| | - Cecile Gallea
- MOV'IT Section (Movement Investigations and Therapeutics), Paris Brain Institute (CNRS/INSERM UMR 7225/1127), Sorbonne Université, 75013 Paris, France
| | - Marie Vidailhet
- Institut du Cerveau et de la Moelle épinière (ICM) UMR 1127, Hôpital de la Pitié-Salpétrière, Department of Neurology, AP-HP, Sorbonne Université, 75013 Paris, France
| | - Arthur W G Buijink
- Department of Neurology, Amsterdam University Medical Centers, 1105 AZ Amsterdam Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
| | - Anne-Fleur van Rootselaar
- Department of Neurology, Amsterdam University Medical Centers, 1105 AZ Amsterdam Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
| | - Bart P C van de Warrenburg
- Department of Neurology, Centre of Expertise for Parkinson & Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands
| | - Rick C Helmich
- Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6500 HB Nijmegen, the Netherlands; Department of Neurology, Centre of Expertise for Parkinson & Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands.
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21
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Gionco JT, Hartstone WG, Martuscello RT, Kuo SH, Faust PL, Louis ED. Essential Tremor versus "ET-plus": A Detailed Postmortem Study of Cerebellar Pathology. CEREBELLUM (LONDON, ENGLAND) 2021; 20:904-912. [PMID: 33768479 PMCID: PMC8972074 DOI: 10.1007/s12311-021-01263-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/16/2021] [Indexed: 12/17/2022]
Abstract
Essential tremor (ET) is among the most prevalent movement disorders, and by some accounts, the most common form of cerebellar degeneration. Over the past 15 years, we have carefully documented a large number of postmortem changes within the cerebellum; these cerebellar changes differ significantly between ET and controls. A recent Consensus Classification of tremor proposed that ET patients with other neurological signs aside from action tremor (e.g., parkinsonism, ataxia, cognitive changes, dystonia) should be segregated off as "ET-plus". This diagnostic concept has raised considerable controversy and its validity is not yet established. Indeed, "ET-plus" has not been distinguished from ET based on differences in genetics, pathology or prognosis. Here we determine whether ET cases differ from "ET-plus" cases in underlying pathological changes in the postmortem brain. We examined postmortem brains from 50 ET cases (24 ET and 26 ET-plus), using a set of 14 quantitative metrics of cerebellar pathology determined by histologic and immunohistochemical methods. These metrics reflect changes across the Purkinje cell (PC) body (PC counts, empty baskets, heterotopias), PC dendrites (swellings), PC axon (torpedoes and associated axonal changes), basket cell axonal hypertrophy and climbing fiber-PC dendrite synaptic changes. ET and ET-plus were similar with respect to 13 of 14 cerebellar pathologic metrics (p > 0.05). Only one metric, the linear density of thickened PC axon profiles, differed between these groups (ET = 0.529 ± 0.397, ET-plus = 0.777 ± 0.477, p = 0.013), although after correcting for multiple comparisons, there were no differences. If ET-plus were indeed a different entity, then the underlying pathological basis should be distinct from that of ET. This study demonstrated there were no pathological differences in cerebellar cortex between ET versus ET-plus cases. These data do not support the notion that ET and ET-plus represent distinct clinical-pathological entities.
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Affiliation(s)
- John T Gionco
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX, 75390-9020, USA.
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22
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Pandey S, Bhattad S. Soft Signs in Essential Tremor Plus: A Prospective Study. Mov Disord Clin Pract 2021; 8:1275-1277. [PMID: 34765694 DOI: 10.1002/mdc3.13350] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/25/2021] [Accepted: 09/13/2021] [Indexed: 01/31/2023] Open
Affiliation(s)
- Sanjay Pandey
- Department of Neurology Govind Ballabh Pant Postgraduate Institute of Medical Education and Research New Delhi India
| | - Sonali Bhattad
- Department of Neurology Govind Ballabh Pant Postgraduate Institute of Medical Education and Research New Delhi India
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23
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Pandey S, Benito-León J, Kuo SH. Editorial: Tremor Syndromes: Current Concepts and Future Perspectives. Front Neurol 2021; 12:752463. [PMID: 34646231 PMCID: PMC8502893 DOI: 10.3389/fneur.2021.752463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sanjay Pandey
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, New Delhi, India
| | - Julián Benito-León
- Department of Neurology, University Hospital, Madrid, Spain.,Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Medicine, Complutense University, Madrid, Spain
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY, United States.,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, United States
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24
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Louis ED, Huey ED, Cosentino S. Features of "ET plus" correlate with age and tremor duration: "ET plus" may be a disease stage rather than a subtype of essential tremor. Parkinsonism Relat Disord 2021; 91:42-47. [PMID: 34482193 DOI: 10.1016/j.parkreldis.2021.08.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/30/2021] [Accepted: 08/29/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Essential tremor (ET) is characterized by considerable clinical heterogeneity. In 2018, the term "ET plus" was introduced to mark a potential stratification point for dividing ET into subtypes - ET vs ET plus (i.e., ET cases with neurological features other than action tremor). However, as ET progresses, patients often develop increasingly severe tremor, spread of tremor, tremor under different activation conditions, and other features. Given this situation, ET plus may represent a disease stage rather than a disease classification or subtype. In theory, if the defining characteristics of a disease subtype fluctuate with age or disease duration, it raises the distinct possibility the "subtype" is a disease stage. METHODS A cohort of 241 prospectively enrolled ET cases underwent a detailed motor and cognitive assessment in which the features of ET plus including cerebellar signs (intention tremor, tandem gait difficulty), rest tremor, dystonia, and cognitive performance were evaluated. We determined whether these features of ET plus correlated with action tremor duration and age. RESULTS We demonstrated that numerous ET plus features were significantly correlated with both age and action tremor duration (numerous p values < 0.05). The same relationships were observed in a series of sensitivity analyses. CONCLUSION We observed that the component parts of ET plus are highly age- and stage-dependent. These features are yearly-changing features conditional on a demographic and disease stage variable. These data support the notion that ET plus may represent a disease stage rather than a distinct disease subtype or disease classification.
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Affiliation(s)
- Elan D Louis
- University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Edward D Huey
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Stephanie Cosentino
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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25
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Abstract
Tremor is the most commonly encountered movement disorder in clinical practice. A wide range of pathologies may manifest with tremor either as a presenting or predominant symptom. Considering the marked etiological and phenomenological heterogeneity, it would be desirable to develop a classification of tremors that reflects their underlying pathophysiology. The tremor task force of the International Parkinson Disease and Movement Disorders Society has worked toward this goal and proposed a new classification system. This system has remained a prime topic of scientific communications on tremor in recent times. The new classification is based on two axes: 1. based on the clinical features, history, and tremor characteristics and 2. based on the etiology of tremor. In this article, we discuss the key aspects of the new classification, review various tremor syndromes, highlight some of the controversies in the field of tremor, and share the potential future perspectives.
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Affiliation(s)
- Abhishek Lenka
- Department of Neurology, Medstar Georgetown University Hospital, Washington, DC, United States
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, United States
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Becktepe J, Gövert F, Balint B, Schlenstedt C, Bhatia K, Elble R, Deuschl G. Exploring Interrater Disagreement on Essential Tremor Using a Standardized Tremor Elements Assessment. Mov Disord Clin Pract 2021; 8:371-376. [PMID: 33816665 PMCID: PMC8015892 DOI: 10.1002/mdc3.13150] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/25/2022] Open
Abstract
Background Patients with upper limb action tremor frequently exhibit additional neurological signs of uncertain significance. Clinicians vary in their interpretation, and interrater agreement on the final diagnosis is poor. Objectives A new clinical tool for assessing the presence or absence of clinical signs that are important in axis‐1 classification of tremor patients is introduced: the Standardized Tremor Elements Assessment (STEA). Interrater agreement is determined, and signs leading to disagreement in the final diagnosis are identified. Methods Three tremor‐focussed and one dystonia‐focussed movement disorder specialists rated 59 videos of patients with upper limb action tremor syndromes using STEA. Interrater agreements for final diagnosis and STEA items were calculated. Results Interrater agreement regarding the final diagnosis was higher within the group of tremor specialists and poor between dystonia and tremor specialists. Greater agreement was found for items characterizing tremor than for signs of dystonia. Conclusions Clinical signs leading to diagnostic disagreement were identified with STEA, and STEA should therefore be useful in future studies of diagnostic disagreement. The thresholds for considering neurological signs as soft versus significant for ataxia, parkinsonism, dystonia, etc. are critically important in tremor classification and must be studied across movement disorder subspecialties, not simply within a pool of tremor specialists.
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Affiliation(s)
- Jos Becktepe
- Department of Neurology University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel Germany
| | - Felix Gövert
- Department of Neurology University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel Germany
| | - Bettina Balint
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London London UK.,Department of Neurology University Hospital Heidelberg Heidelberg Germany
| | - Christian Schlenstedt
- Department of Neurology University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel Germany
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London London UK
| | - Rodger Elble
- Department of Neurology Southern Illinois University School of Medicine Springfield Illinois USA
| | - Günther Deuschl
- Department of Neurology University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel Germany
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Phenotypic Features of Isolated Essential Tremor, Essential Tremor Plus, and Essential Tremor-Parkinson's Disease in a Movement Disorders Clinic. Tremor Other Hyperkinet Mov (N Y) 2021; 11:12. [PMID: 33828900 PMCID: PMC8015706 DOI: 10.5334/tohm.581] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Patients with essential tremor were initially considered to have isolated tremor, but additional motor and non-motor features have been increasingly recognized. The term “essential tremor plus” was adopted by the Task Force on Tremor of the International Parkinson and Movement Disorder Society to describe essential tremor patients with additional neurologic signs. Objectives: To characterize essential tremor patients and their phenotypes in a movement disorders clinic population in the context of the new tremor classification. Methods: Demographic, clinical, historical, treatment, and diagnostic data were retrospectively collected on 300 patients diagnosed by movement disorder experts with essential tremor. Patients were classified as having essential tremor, essential tremor plus, or essential tremor-Parkinson’s disease combination, and features between these groups were compared. Results: Of the 300 patients, 20.7% were classified as isolated essential tremor, 53.3% as essential tremor plus, and 26.0% as essential tremor-Parkinson’s disease. There was no significant difference in the duration of tremor symptoms. Essential tremor plus patients were more likely to have dystonia, tandem gait abnormalities, head tremor and greater tremor severity. Essential tremor-Parkinson’s disease patients were more likely to have RBD symptoms. There was no significant difference in cognitive impairment between essential tremor plus and essential tremor-Parkinson’s disease patients. Conclusions: Additional motor and non-motor features, including parkinsonism, are common in patients with essential tremor. Further studies are needed to clarify essential tremor phenotypes and to provide insights into possible subtypes. Highlights: 300 patients with essential tremor from a movement disorders clinic were re-classified based on the Movement Disorder Society Consensus Statement on the Classification of Tremors. Additional motor and non-motor features, including parkinsonism, were common, and only 20.7% of patients remained classified as isolated essential tremor.
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Louis ED. The Essential Tremors: Evolving Concepts of a Family of Diseases. Front Neurol 2021; 12:650601. [PMID: 33841316 PMCID: PMC8032967 DOI: 10.3389/fneur.2021.650601] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/12/2021] [Indexed: 12/31/2022] Open
Abstract
The past 10 years has seen a remarkable advance in our understanding of the disease traditionally referred to as “essential tremor” (ET). First, the clinical phenotype of ET has been expanded from that of a bland, unidimensional, and monosymptomatic entity to one with a host of heterogeneous features. These features include a broader and more nuanced collection of tremors, non-tremor motor features (e.g., gait abnormalities) and a range of non-motor features, including cognitive, psychiatric, sleep, and other abnormalities. The natural history of these features, as well as their relationships with one another and with disease duration and severity, are better appreciated than they were previously. Studies of disease etiology have identified a number of candidate genes as well as explored several environmental determinants of disease. In addition, the decade has seen the beginnings and expansion of rigorous postmortem studies that have identified and described the postmortem changes in the brains of patients with ET. This emerging science has given rise to a new notion that the disease, in many cases, is one of cerebellar system degeneration. Across all of these studies (clinical, etiological, and pathophysiological) is the observation that there is heterogeneity across patients and that “essential tremor” is likely not a single disease but, rather, a family of diseases. The time has come to use the more appropriate terminology, “the essential tremors,” to fully describe and encapsulate what is now apparent. In this paper, the author will review the clinical, etiological, and pathophysiological findings, referred to above, and make the argument that the terminology should evolve to reflect advances in science and that “the essential tremors” is a more scientifically appropriate term.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern, Dallas, TX, United States
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