1
|
Faust PL, McCreary M, Musacchio JB, Kuo S, Vonsattel JG, Louis ED. Pathologically based criteria to distinguish essential tremor from controls: analyses of the human cerebellum. Ann Clin Transl Neurol 2024; 11:1514-1525. [PMID: 38644741 PMCID: PMC11187833 DOI: 10.1002/acn3.52068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 04/02/2024] [Indexed: 04/23/2024] Open
Abstract
OBJECTIVE Essential tremor is among the most prevalent neurological diseases. Diagnosis is based entirely on neurological evaluation. Historically, there were few postmortem brain studies, hindering attempts to develop pathologically based criteria to distinguish essential tremor from control brains. However, an intensive effort to bank essential tremor brains over recent years has resulted in postmortem studies involving >200 brains, which have identified numerous degenerative changes in the essential tremor cerebellar cortex. Although essential tremor and controls have been compared with respect to individual metrics of pathology, there has been no overarching analysis to derive a combination of metrics to distinguish essential tremor from controls. We asked whether there is a constellation of pathological findings that separates essential tremor from controls, and how well that constellation performs. METHODS Analyses included 100 essential tremor brains from the essential tremor centralized brain repository and 50 control brains. A standard tissue block from the cerebellar cortex was used to quantify 11 metrics of pathological change. Three supervised classification algorithms were investigated, with data divided into training and validation samples. RESULTS Using three different algorithms, we illustrate the ability to correctly predict a diagnosis of essential tremor, with sensitivity and specificity >87%, and in the majority of situations, >90%. We also provide a web-based application that uses these metric values, and based on specified cutoffs, determines the likely diagnosis. INTERPRETATION These analyses set the stage for use of pathologically based criteria to distinguish clinically diagnosed essential tremor cases from controls, at the time of postmortem.
Collapse
Affiliation(s)
- Phyllis L. Faust
- Department of Pathology and Cell BiologyColumbia University Irving Medical Center, New York Presbyterian HospitalNew YorkNew YorkUSA
| | - Morgan McCreary
- Statistical Planning and Analysis Section, Department of NeurologyUniversity of Texas SouthwesternDallasTexasUSA
| | - Jessica B. Musacchio
- Department of Pathology and Cell BiologyColumbia University Irving Medical Center, New York Presbyterian HospitalNew YorkNew YorkUSA
| | - Sheng‐Han Kuo
- Department of Neurology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Jean‐Paul G. Vonsattel
- Department of Pathology and Cell BiologyColumbia University Irving Medical Center, New York Presbyterian HospitalNew YorkNew YorkUSA
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
| | - Elan D. Louis
- Department of NeurologyUniversity of Texas SouthwesternDallasTexasUSA
| |
Collapse
|
2
|
Zeng S, Zhou X, He R, Zhao Y, Liu Z, Xu Q, Guo J, Yan X, Li J, Tang B, Sun Q. Association Analysis of Essential Tremor-Associated Genetic Variants in Sporadic Late-Onset Parkinson's Disease. Tremor Other Hyperkinet Mov (N Y) 2024; 14:25. [PMID: 38737298 PMCID: PMC11086585 DOI: 10.5334/tohm.885] [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: 02/26/2024] [Accepted: 04/25/2024] [Indexed: 05/14/2024] Open
Abstract
Background Parkinson's disease (PD) and Essential tremor (ET) are the two most common tremor diseases with recognized genetic pathogenesis. The overlapping clinical features suggest they may share genetic predispositions. Our previous study systematically investigated the association between rare coding variants in ET-associated genes and early-onset PD (EOPD), and found the suggestive association between teneurin transmembrane protein 4 (TENM4) and EOPD. In the current research, we explored the potential genetic interplay between ET-associated genetic loci/genes and sporadic late-onset PD (LOPD). Methods We performed whole-genome sequencing in the 1962 sporadic LOPD cases and 1279 controls from mainland China. We first used logistic regression analysis to test the top 16 SNPs identified by the ET genome-wide association study for the association between ET and LOPD. Then we applied the optimized sequence kernel association testing to explore the rare variant burden of 33 ET-associated genes in this cohort. Results We did not observe a significant association between the included SNPs with LOPD. We also did not discover a significant burden of rare deleterious variants of ET-associated genes in association with LOPD risk. Conclusion Our results do not support the role of ET-associated genetic loci and variants in LOPD. Highlights 1962 cases and 1279 controls were recruited to study the potential genetic interplay between ET-associated genetic loci/variants and sporadic LOPD.No significant association between the ET-associated SNPs and LOPD were observed.No significant burden of rare deleterious variants of ET-associated gene in LOPD risk were found.
Collapse
Affiliation(s)
- Sheng Zeng
- Department of Geriatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
| | - Xun Zhou
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Runcheng He
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Yuwen Zhao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Zhenhua Liu
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Qian Xu
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Jifeng Guo
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Xinxiang Yan
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Jinchen Li
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Beisha Tang
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410008, China
| | - Qiying Sun
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410008, China
| |
Collapse
|
3
|
Martuscello RT, Sivaprakasam K, Hartstone W, Kuo SH, Konopka G, Louis ED, Faust PL. Gene Expression Analysis of Laser-Captured Purkinje Cells in the Essential Tremor Cerebellum. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1166-1181. [PMID: 36242761 PMCID: PMC10359949 DOI: 10.1007/s12311-022-01483-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 12/13/2022]
Abstract
Essential tremor (ET) is a common, progressive neurological disease characterized by an 8-12-Hz kinetic tremor. Despite its high prevalence, the patho-mechanisms of tremor in ET are not fully known. Through comprehensive studies in postmortem brains, we identified major morphological changes in the ET cerebellum that reflect cellular damage in Purkinje cells (PCs), suggesting that PC damage is central to ET pathogenesis. We previously performed a transcriptome analysis in ET cerebellar cortex, identifying candidate genes and several dysregulated pathways. To directly target PCs, we purified RNA from PCs isolated by laser capture microdissection and performed the first ever PC-specific RNA-sequencing analysis in ET versus controls. Frozen postmortem cerebellar cortex from 24 ETs and 16 controls underwent laser capture microdissection, obtaining ≥2000 PCs per sample. RNA transcriptome was analyzed via differential gene expression, principal component analysis (PCA), and gene set enrichment analyses (GSEA). We identified 36 differentially expressed genes, encompassing multiple cellular processes. Some ET (13/24) had greater dysregulation of these genes and segregated from most controls and remaining ETs in PCA. Characterization of genes/pathways enriched in this PCA and GSEA identified multiple pathway dysregulations in ET, including RNA processing/splicing, synapse organization/ion transport, and oxidative stress/inflammation. Furthermore, a different set of pathways characterized marked heterogeneity among ET patients. Our data indicate a range of possible mechanisms for the pathogenesis of ET. Significant heterogeneity among ET combined with dysregulation of multiple cellular processes supports the notion that ET is a family of disorders rather than one disease entity.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA
| | - Karthigayini Sivaprakasam
- Peter O'Donnell Jr. Brain Institute, Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Whitney Hartstone
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, 650 W 168th Street, BB302, New York, NY, USA
| | - Genevieve Konopka
- Peter O'Donnell Jr. Brain Institute, Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Suite NL9.114, Dallas, TX, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA.
| |
Collapse
|
4
|
Martuscello RT, Chen ML, Reiken S, Sittenfeld LR, Ruff DS, Ni CL, Lin CC, Pan MK, Louis ED, Marks AR, Kuo SH, Faust PL. Defective cerebellar ryanodine receptor type 1 and endoplasmic reticulum calcium 'leak' in tremor pathophysiology. Acta Neuropathol 2023; 146:301-318. [PMID: 37335342 PMCID: PMC10350926 DOI: 10.1007/s00401-023-02602-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 06/21/2023]
Abstract
Essential Tremor (ET) is a prevalent neurological disease characterized by an 8-10 Hz action tremor. Molecular mechanisms of ET remain poorly understood. Clinical data suggest the importance of the cerebellum in disease pathophysiology, and pathological studies indicate Purkinje Cells (PCs) incur damage. Our recent cerebellar cortex and PC-specific transcriptome studies identified alterations in calcium (Ca2+) signaling pathways that included ryanodine receptor type 1 (RyR1) in ET. RyR1 is an intracellular Ca2+ release channel located on the Endoplasmic Reticulum (ER), and in cerebellum is predominantly expressed in PCs. Under stress conditions, RyR1 undergoes several post-translational modifications (protein kinase A [PKA] phosphorylation, oxidation, nitrosylation), coupled with depletion of the channel-stabilizing binding partner calstabin1, which collectively characterize a "leaky channel" biochemical signature. In this study, we found markedly increased PKA phosphorylation at the RyR1-S2844 site, increased RyR1 oxidation and nitrosylation, and calstabin1 depletion from the RyR1 complex in postmortem ET cerebellum. Decreased calstabin1-RyR1-binding affinity correlated with loss of PCs and climbing fiber-PC synapses in ET. This 'leaky' RyR1 signature was not seen in control or Parkinson's disease cerebellum. Microsomes from postmortem cerebellum demonstrated excessive ER Ca2+ leak in ET vs. controls, attenuated by channel stabilization. We further studied the role of RyR1 in tremor using a mouse model harboring a RyR1 point mutation that mimics constitutive site-specific PKA phosphorylation (RyR1-S2844D). RyR1-S2844D homozygous mice develop a 10 Hz action tremor and robust abnormal oscillatory activity in cerebellar physiological recordings. Intra-cerebellar microinfusion of RyR1 agonist or antagonist, respectively, increased or decreased tremor amplitude in RyR1-S2844D mice, supporting a direct role of cerebellar RyR1 leakiness for tremor generation. Treating RyR1-S2844D mice with a novel RyR1 channel-stabilizing compound, Rycal, effectively dampened cerebellar oscillatory activity, suppressed tremor, and normalized cerebellar RyR1-calstabin1 binding. These data collectively support that stress-associated ER Ca2+ leak via RyR1 may contribute to tremor pathophysiology.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, 630 W 168th Street, PH Stem 15-124, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Meng-Ling Chen
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - Leah R Sittenfeld
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - David S Ruff
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Chun-Lun Ni
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Chih-Chun Lin
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Ming-Kai Pan
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Andrew R Marks
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, 630 W 168th Street, PH Stem 15-124, New York, NY, 10032, USA.
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA.
| |
Collapse
|
5
|
Fanning A, Kuo SH. Clinical Heterogeneity of Essential Tremor: Understanding Neural Substrates of Action Tremor Subtypes. CEREBELLUM (LONDON, ENGLAND) 2023:10.1007/s12311-023-01551-3. [PMID: 37022657 PMCID: PMC10556200 DOI: 10.1007/s12311-023-01551-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/21/2023] [Indexed: 04/07/2023]
Abstract
Essential tremor (ET) is a common movement disorder affecting millions of people. Studies of ET patients and perturbations in animal models have provided a foundation for the neural networks involved in its pathophysiology. However, ET encompasses a wide variability of phenotypic expression, and this may be the consequence of dysfunction in distinct subcircuits in the brain. The cerebello-thalamo-cortical circuit is a common substrate for the multiple subtypes of action tremor. Within the cerebellum, three sets of cerebellar cortex-deep cerebellar nuclei connections are important for tremor. The lateral hemispheres and dentate nuclei may be involved in intention, postural and isometric tremor. The intermediate zone and interposed nuclei could be involved in intention tremor. The vermis and fastigial nuclei could be involved in head and proximal upper extremity tremor. Studying distinct cerebellar circuitry will provide important framework for understanding the clinical heterogeneity of ET.
Collapse
Affiliation(s)
- Alexander Fanning
- Department of Neurology, Columbia University, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, 10032, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY, 10032, USA.
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, 10032, USA.
| |
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| |
Collapse
|
7
|
Wang X, St George RJ, Bai Q, Tran SN, Alty J. Differences in clinical manifestations of late-onset, compared to earlier-onset essential tremor: A scoping review. J Neurol Sci 2022; 440:120336. [PMID: 35843178 DOI: 10.1016/j.jns.2022.120336] [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: 03/29/2022] [Revised: 06/03/2022] [Accepted: 07/05/2022] [Indexed: 11/24/2022]
Abstract
Across the world, Essential Tremor (ET) is the most common tremor diagnosis but up to half of these diagnoses are inaccurate. The misdiagnosis rate is particularly high in late-onset ET, when tremor begins after the age of 60 years. Currently, ET is reported to affect 5.5% of those over 65 years old and 21.7% aged over 95 but there is emerging evidence that late-onset ET has associations with dementia, mortality and more rapid progression. With ageing populations, and a range of new surgical treatments for ET, there is urgent need to clarify whether the clinical manifestations of late-onset ET are the same as for earlier-onset ET. This scoping review used MEDLINE, EMBASE and CINAHL as the information sources of published peer-reviewed research articles between 2011 and 2021. Analysis was done by narrative synthesis. 14 relevant papers were retrieved from studies conducted in Denmark, India, Italy, Germany, Spain and the US and, together, they comprised 7684 participants in total. Compared to older adults with earlier-onset ET, there is evidence that late-onset ET is associated with higher risk of cognitive impairment and dementia, higher mortality rate, faster rate of progression, lack of family history, altered cortical electrical activity, prolonged pupillary responses, and less propensity to demonstrate characteristic alcohol sensitivity. There is evidence that late-onset ET has different clinical manifestations to earlier-onset ET; in particular there is higher risk of dementia and mortality. The prognosis is important for clinicians to consider when selecting candidates for deep brain stimulation surgery and also for advanced care planning.
Collapse
Affiliation(s)
- Xinyi Wang
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, 17 Liverpool St, Hobart, Australia
| | - Rebecca J St George
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, 17 Liverpool St, Hobart, Australia; School of Psychological Sciences, College of Health and Medicine, University of Tasmania, Churchill Ave, Hobart, Australia
| | - Quan Bai
- Department of Information and Communication Technology, College of Science and Engineering, Churchill Ave, Hobart, Australia
| | - Son N Tran
- Department of Information and Communication Technology, College of Science and Engineering, Churchill Ave, Hobart, Australia
| | - Jane Alty
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, 17 Liverpool St, Hobart, Australia; School of Medicine, College of Health and Medicine, University of Tasmania, 17 Liverpool St, Hobart, Australia; Department of Neurology, Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds, UK.
| |
Collapse
|
8
|
Bellows S, Jimenez-Shahed J. Is essential tremor a disorder of GABA dysfunction? No. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:285-310. [PMID: 35750366 DOI: 10.1016/bs.irn.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although essential tremor is common, its underlying pathophysiology remains uncertain, and several hypotheses seek to explain the tremor mechanism. The GABA hypothesis states that disinhibition of deep cerebellar neurons due to reduced GABAergic input from Purkinje cells results in increased pacemaker activity, leading to rhythmic output to the thalamo-cortical circuit and resulting in tremor. However, some neuroimaging, spectroscopy, and pathology studies have not shown a clear or consistent GABA deficiency in essential tremor, and animal models have indicated that large reductions of Purkinje cell inhibition may improve tremor. Instead, tremor is increasingly attributable to dysfunction in oscillating networks, where altered (but not necessarily reduced) inhibitory signaling can result in tremor. Hypersynchrony of Purkinje cell activity may account for excessive oscillatory cerebellar output, with potential contributions along multiple sites of the olivocerebellar loop. Although older animal tremor models, such as harmaline tremor, have explored contributions from the inferior olivary body, increasing evidence has pointed to the role of aberrant climbing fiber synaptic organization in oscillatory cerebellar activity and tremor generation. New animal models such as hotfoot17j mice, which exhibit abnormal climbing fiber organization due to mutations in Grid2, have recapitulated many features of ET. Similar abnormal climbing fiber architecture and excessive cerebellar oscillations as measured by EEG have been found in humans with essential tremor. Further understanding of hypersynchrony and excessive oscillatory activity in ET phenotypes may lead to more targeted and effective treatment options.
Collapse
|
9
|
Pan MK, Kuo SH. Essential tremor: Clinical perspectives and pathophysiology. J Neurol Sci 2022; 435:120198. [PMID: 35299120 PMCID: PMC10363990 DOI: 10.1016/j.jns.2022.120198] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
Essential tremor (ET) is one of the most common neurological disorders and can be highly disabling. In recent years, studies on the clinical perspectives and pathophysiology have advanced our understanding of ET. Specifically, clinical heterogeneity of ET, with co-existence of tremor and other neurological features such as dystonia, ataxia, and cognitive dysfunction, has been identified. The cerebellum has been found to be the key brain region for tremor generation, and structural alterations of the cerebellum have been extensively studied in ET. Finally, four main ET pathophysiologies have been proposed: 1) environmental exposures to β-carboline alkaloids and the consequent olivocerebellar hyper-excitation, 2) cerebellar GABA deficiency, 3) climbing fiber synaptic pathology with related cerebellar oscillatory activity, 4) extra-cerebellar oscillatory activity. While these four theories are not mutually exclusive, they can represent distinctive ET subtypes, indicating multiple types of abnormal brain circuitry can lead to action tremor. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.
Collapse
|
10
|
Woodward K, Apps R, Goodfellow M, Cerminara NL. Cerebello-Thalamo-Cortical Network Dynamics in the Harmaline Rodent Model of Essential Tremor. Front Syst Neurosci 2022; 16:899446. [PMID: 35965995 PMCID: PMC9365993 DOI: 10.3389/fnsys.2022.899446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/22/2022] [Indexed: 11/18/2022] Open
Abstract
Essential Tremor (ET) is a common movement disorder, characterised by a posture or movement-related tremor of the upper limbs. Abnormalities within cerebellar circuits are thought to underlie the pathogenesis of ET, resulting in aberrant synchronous oscillatory activity within the thalamo-cortical network leading to tremors. Harmaline produces pathological oscillations within the cerebellum, and a tremor that phenotypically resembles ET. However, the neural network dynamics in cerebellar-thalamo-cortical circuits in harmaline-induced tremor remains unclear, including the way circuit interactions may be influenced by behavioural state. Here, we examined the effect of harmaline on cerebello-thalamo-cortical oscillations during rest and movement. EEG recordings from the sensorimotor cortex and local field potentials (LFP) from thalamic and medial cerebellar nuclei were simultaneously recorded in awake behaving rats, alongside measures of tremor using EMG and accelerometery. Analyses compared neural oscillations before and after systemic administration of harmaline (10 mg/kg, I.P), and coherence across periods when rats were resting vs. moving. During movement, harmaline increased the 9-15 Hz behavioural tremor amplitude and increased thalamic LFP coherence with tremor. Medial cerebellar nuclei and cerebellar vermis LFP coherence with tremor however remained unchanged from rest. These findings suggest harmaline-induced cerebellar oscillations are independent of behavioural state and associated changes in tremor amplitude. By contrast, thalamic oscillations are dependent on behavioural state and related changes in tremor amplitude. This study provides new insights into the role of cerebello-thalamo-cortical network interactions in tremor, whereby neural oscillations in thalamocortical, but not cerebellar circuits can be influenced by movement and/or behavioural tremor amplitude in the harmaline model.
Collapse
Affiliation(s)
- Kathryn Woodward
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Richard Apps
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Marc Goodfellow
- Department of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Nadia L. Cerminara
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
- *Correspondence: Nadia L. Cerminara
| |
Collapse
|
11
|
Is essential tremor a degenerative disorder or an electric disorder? Degenerative disorder. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:65-101. [PMID: 35750370 PMCID: PMC9846862 DOI: 10.1016/bs.irn.2022.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Essential tremor (ET) is a highly prevalent neurologic disease and is the most common of the many tremor disorders. ET is a progressive condition with marked clinical heterogeneity, associated with a spectrum of both motor and non-motor features. However, its disease mechanisms remain poorly understood. Much debate has centered on whether ET should be considered a degenerative disorder, with underlying pathological changes in brain causing progressive disease manifestations, or an electric disorder, with overactivity of intrinsically oscillatory motor networks that occur without underlying structural brain abnormalities. Converging data from clinical, neuroimaging and pathological studies in ET now provide considerable evidence for the neurodegenerative hypothesis. A major turning point in this debate is that rigorous tissue-based studies have recently identified a series of structural changes in the ET cerebellum. Most of these pathological changes are centered on the Purkinje cell and connected neuronal populations, which can result in partial loss of Purkinje cells and circuitry reorganizations that would disturb cerebellar function. There is significant overlap in clinical and pathological features of ET with other disorders of cerebellar degeneration, and an increased risk of developing other degenerative diseases in ET. The combined implication of these studies is that ET could be degenerative. The evidence in support of the degenerative hypothesis is presented.
Collapse
|
12
|
Lang EJ, Handforth A. Is the inferior olive central to essential tremor? Yes. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:133-165. [PMID: 35750361 DOI: 10.1016/bs.irn.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We consider the question whether the inferior olive (IO) is required for essential tremor (ET). Much evidence shows that the olivocerebellar system is the main system capable of generating the widespread synchronous oscillatory Purkinje cell (PC) complex spike (CS) activity across the cerebellar cortex that would be capable of generating the type of bursting cerebellar output from the deep cerebellar nuclei (DCN) that could underlie tremor. Normally, synchronous CS activity primarily reflects the effective electrical coupling of IO neurons by gap junctions, and traditionally, ET research has focused on the hypothesis of increased coupling of IO neurons as the cause of hypersynchronous CS activity underlying tremor. However, recent pathology studies of brains from humans with ET and evidence from mutant mice, particularly the hotfoot17 mouse, that largely replicate the pathology of ET, suggest that the abnormal innervation of multiple Purkinje cells (PCs) by climbing fibers (Cfs) is related to tremor. In addition, ET brains show partial PC loss and axon terminal sprouting by surviving PCs. This may provide another mechanism for tremor. It is proposed that in ET, these three mechanisms may promote tremor. They all involve hypersynchronous DCN activity and an intact IO, but the level at which excessive synchronization occurs may be at the IO level (from abnormal afferent activity to this nucleus), the PC level (via aberrant Cfs), or the DCN level (via terminal PC collateral innervation).
Collapse
|
13
|
Abstract
Essential tremor (ET) is one of the most common movement disorders, with a reported >60 million affected individuals worldwide. The definition and underlying pathophysiology of ET are contentious. Patients present primarily with motor features such as postural and action tremors, but may also have other non-motor features, including cognitive impairment and neuropsychiatric symptoms. Genetics account for most of the ET risk but environmental factors may also be involved. However, the variable penetrance and challenges in validating data make gene-environment analysis difficult. Structural changes in cerebellar Purkinje cells and neighbouring neuronal populations have been observed in post-mortem studies, and other studies have found GABAergic dysfunction and dysregulation of the cerebellar-thalamic-cortical circuitry. Commonly prescribed medications include propranolol and primidone. Deep brain stimulation and ultrasound thalamotomy are surgical options in patients with medically intractable ET. Further research in post-mortem studies, and animal and cell-based models may help identify new pathophysiological clues and therapeutic targets and, together with advances in omics and machine learning, may facilitate the development of precision medicine for patients with ET.
Collapse
|
14
|
Roque DA, Hadar E, Zhang Y, Zou F, Murrow R. Reducing Ataxic Side Effects from Ventral Intermediate Nucleus of the Thalamus Deep Brain Stimulation Implantation in Essential Tremor: Potential Advantages of Directional Stimulation. Stereotact Funct Neurosurg 2021; 100:35-43. [PMID: 34535594 DOI: 10.1159/000518238] [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: 05/06/2021] [Accepted: 06/30/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The aim of the study was to retrospectively evaluate the effect of directional deep brain stimulation (DBS) on ataxia in an essential tremor patient population. MATERIALS AND METHODS A retrospective chart review of documented Scale for Assessment and Rating of Ataxia (SARA) scores were analyzed using a case-control design. All subjects we evaluated were treated at a single, tertiary care academic center. We reviewed 14 patients who underwent bilateral ventral intermediate nucleus of the thalamus (VIM) implantation with microelectrode recording, with electrodeposition and segmented contact orientation confirmed via postoperative computed tomography. The main outcome was to determine change in ataxia scores between directional versus monopolar circumferential stimulation. RESULTS Fourteen patients (9 males, median age at implantation 69 [range 63-82]) underwent surgery between October 2017 and July 2020 at the UNC Movement Disorders Center. SARA scores between directional stimulation and monopolar circumferential stimulation demonstrated a significant reduction in total scores with best possible segmented stimulation (n = 13, p < 0.0001, 95% confidence interval [CI] -3.496 to -6.789). This difference remained statistically significant even after removing the SARA tremor subscore (n = 13, p < 0.0001, 95% CI -3.155 to -6.274). In line with prior reports, SARA score changes from the preoperative state were generally worsened when applying monopolar circumferential stimulation bilaterally (n = 13, p = 0.655; 95% CI -2.836 to 4.359), but improved with directional stimulation (n = 13, p = 0.010; 95% CI -1.216 to -7.547). CONCLUSION This retrospective analysis appears to show evidence for improved outcomes through directional stimulation in bilateral VIM DBS implantation with reduction of ataxic side effects that have traditionally plagued postoperative results, all while providing optimized tremor reduction via stimulation.
Collapse
Affiliation(s)
- Daniel Alberto Roque
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Eldad Hadar
- Department of Neurosurgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ying Zhang
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Fei Zou
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Richard Murrow
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
15
|
Wu YC, Louis ED, Gionco J, Pan MK, Faust PL, Kuo SH. Increased Climbing Fiber Lateral Crossings on Purkinje Cell Dendrites in the Cerebellar Hemisphere in Essential Tremor. Mov Disord 2021; 36:1440-1445. [PMID: 33497495 PMCID: PMC8217183 DOI: 10.1002/mds.28502] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 12/21/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Climbing fibers (CFs) innervate Purkinje cells (PCs) with 1:1 relationship to ensure proper cerebellar function. Although CFs abnormally extend into the parallel fiber domain of PC dendrites in essential tremor (ET), the architecture of CFs in relation to PCs has yet to be investigated in detail. OBJECTIVE The aim of this work was to study the architecture of CFs in relation to PCs in ET. METHODS The number of PC somas and PC dendrites that a single CF crossed was quantified in the postmortem cerebellum of 15 ET cases and 15 control cases. RESULTS In ET, CFs crossed a greater number of PC somas and PC dendrites than in control cases, raising the possibility that there is abnormal CF wiring onto the PCs. Interestingly, the increase in CF-PC crossings positively correlated with tremor severity. CONCLUSIONS Patients with ET have increased CF crossings on PC dendrites. This abnormal architectural arrangement may contribute to synchronous brain activity and tremor. © 2021 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Yueh-Chi Wu
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
| | - Elan D. Louis
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, Texas, USA
| | - John Gionco
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Ming-Kai Pan
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Phyllis L. Faust
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
| |
Collapse
|
16
|
Pan MK, Li YS, Wong SB, Ni CL, Wang YM, Liu WC, Lu LY, Lee JC, Cortes EP, Vonsattel JPG, Sun Q, Louis ED, Faust PL, Kuo SH. Cerebellar oscillations driven by synaptic pruning deficits of cerebellar climbing fibers contribute to tremor pathophysiology. Sci Transl Med 2021; 12:12/526/eaay1769. [PMID: 31941824 DOI: 10.1126/scitranslmed.aay1769] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/15/2019] [Indexed: 12/13/2022]
Abstract
Essential tremor (ET) is one of the most common movement disorders and the prototypical disorder for abnormal rhythmic movements. However, the pathophysiology of tremor generation in ET remains unclear. Here, we used autoptic cerebral tissue from patients with ET, clinical data, and mouse models to report that synaptic pruning deficits of climbing fiber (CF)-to-Purkinje cell (PC) synapses, which are related to glutamate receptor delta 2 (GluRδ2) protein insufficiency, cause excessive cerebellar oscillations and might be responsible for tremor. The CF-PC synaptic pruning deficits were correlated with the reduction in GluRδ2 expression in the postmortem ET cerebellum. Mice with GluRδ2 insufficiency and CF-PC synaptic pruning deficits develop ET-like tremor that can be suppressed with viral rescue of GluRδ2 protein. Step-by-step optogenetic or pharmacological inhibition of neuronal firing, axonal activity, or synaptic vesicle release confirmed that the activity of the excessive CF-to-PC synapses is required for tremor generation. In vivo electrophysiology in mice showed that excessive cerebellar oscillatory activity is CF dependent and necessary for tremor and optogenetic-driven PC synchronization was sufficient to generate tremor in wild-type animals. Human validation by cerebellar electroencephalography confirmed that excessive cerebellar oscillations also exist in patients with ET. Our findings identify a pathophysiologic contribution to tremor at molecular (GluRδ2), structural (CF-to-PC synapses), physiological (cerebellar oscillations), and behavioral levels (kinetic tremor) that might have clinical applications for treating ET.
Collapse
Affiliation(s)
- Ming-Kai Pan
- Department of Medical Research, National Taiwan University Hospital, Taipei City 10002, Taiwan. .,Institute of Pharmacology, College of Medicine, National Taiwan University Hospital, Taipei City 10051, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei City 10051, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei City 10051, Taiwan.,Department of Neurology, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin 64041, Taiwan
| | - Yong-Shi Li
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Shi-Bing Wong
- Department of Neurology, Columbia University, New York, NY 10032, USA.,Department of Pediatrics, Taipei Tzu Chi Hospital, Tzu Chi Medical Foundation, New Taipei City 23142, Taiwan
| | - Chun-Lun Ni
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Yi-Mei Wang
- Department of Neurology, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin 64041, Taiwan
| | - Wen-Chuan Liu
- Department of Medical Research, National Taiwan University Hospital, Taipei City 10002, Taiwan.,Institute of Pharmacology, College of Medicine, National Taiwan University Hospital, Taipei City 10051, Taiwan
| | - Liang-Yin Lu
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei City 10051, Taiwan
| | - Jye-Chang Lee
- Molecular Imaging Center, National Taiwan University, Taipei City 10051, Taiwan
| | - Etty P Cortes
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Jean-Paul G Vonsattel
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Qian Sun
- Department of Neuroscience, Columbia University, New York, NY 10032, USA.,Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44016, USA
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT 06519, USA.,Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT 06510, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY 10032, USA. .,Initiative of Columbia Ataxia and Tremor, New York, NY 10032, USA
| |
Collapse
|
17
|
Shalash AS, Hamid E, Elrassas H, Bahbah EI, Mansour AH, Mohamed H, Elbalkimy M. Non-motor symptoms in essential tremor, akinetic rigid and tremor-dominant subtypes of Parkinson's disease. PLoS One 2021; 16:e0245918. [PMID: 33503062 PMCID: PMC7840014 DOI: 10.1371/journal.pone.0245918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 01/10/2021] [Indexed: 12/30/2022] Open
Abstract
Objectives To compare non-motor symptoms (NMSs) among patients with essential tremor (ET), Parkinson’s disease (PD) subtypes (akinetic-rigid type (ART) and tremor-dominant type (TDT)), and healthy controls. Patients and methods This retrospective study included 129 participants, 72 PD (33 PD-ART, 33 PD-TDT, and 6 Mixed), 29 ET patients, and 28 controls. PD patients were assessed by the unified Parkinson’s disease rating scale (UPDRS), Hoehn, and Yahr scale (H&Y), while ET patients were evaluated by the Fahn Tolosa Marin Tremor Rating Scale. All subjects were evaluated by non-motor symptoms scale (NMSS) for NMSs and Beck depression inventory (BDI) for depression. Results PD subtypes groups, ET, and controls were age and gender-matched. Compared to controls, all PD, PD subtypes, and ET showed significantly worse most of NMSs (p<0.001) and depression. Compared to ET, all PD and PD-ART had significantly worse gastrointestinal (p = 0.002), urinary symptoms (p = 0.001, p = 0.003) and depression (p = 0.002) and PD-TDT worse depression, while ET patients showed worse memory/attention than PD subtypes. Total NMSS of ET is highly correlated to depression and moderately to tremor severity and age of onset, while total of NMSS is highly correlated to depression, disease severity, and disability. Conclusion The current study demonstrated several comparable domains of NMSs of PD subtypes and ET, except worse gastrointestinal and urinary symptoms among PD-ART. Identifying different NMSs profiles is important for predicting, better assessing, and tailoring management of ET and PD subtypes.
Collapse
Affiliation(s)
- Ali S Shalash
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Eman Hamid
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Hanan Elrassas
- Okasha Institute of Psychiatry, Ain Shams University, Cairo, Egypt
| | - Eshak I Bahbah
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Alia H Mansour
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Hadeer Mohamed
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Mahmoud Elbalkimy
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| |
Collapse
|
18
|
Ibrahim MF, Beevis JC, Empson RM. Essential Tremor - A Cerebellar Driven Disorder? Neuroscience 2020; 462:262-273. [PMID: 33212218 DOI: 10.1016/j.neuroscience.2020.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 10/23/2020] [Accepted: 11/01/2020] [Indexed: 02/07/2023]
Abstract
Abnormal tremors are the most common of all movement disorders. In this review we focus on the role of the cerebellum in Essential Tremor, a highly debilitating but poorly treated movement disorder. We propose a variety of mechanisms driving abnormal burst firing of deep cerebellar nuclei neurons as a key initiator of tremorgenesis in Essential Tremor. Targetting these mechanisms may generate more effective treatments for Essential Tremor.
Collapse
Affiliation(s)
- Mohamed Fasil Ibrahim
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand.
| | - Jessica C Beevis
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Ruth M Empson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| |
Collapse
|
19
|
Handforth A, Lang EJ. Increased Purkinje Cell Complex Spike and Deep Cerebellar Nucleus Synchrony as a Potential Basis for Syndromic Essential Tremor. A Review and Synthesis of the Literature. THE CEREBELLUM 2020; 20:266-281. [PMID: 33048308 DOI: 10.1007/s12311-020-01197-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 12/19/2022]
Abstract
We review advances in understanding Purkinje cell (PC) complex spike (CS) physiology that suggest increased CS synchrony underlies syndromic essential tremor (ET). We searched PubMed for papers describing factors that affect CS synchrony or cerebellar circuits potentially related to tremor. Inferior olivary (IO) neurons are electrically coupled, with the degree of coupling controlled by excitatory and GABAergic inputs. Clusters of coupled IO neurons synchronize CSs within parasagittal bands via climbing fibers (Cfs). When motor cortex is stimulated in rats at varying frequencies, whisker movement occurs at ~10 Hz, correlated with synchronous CSs, indicating that the IO/CS oscillatory rhythm gates movement frequency. Intra-IO injection of the GABAA receptor antagonist picrotoxin increases CS synchrony, increases whisker movement amplitude, and induces tremor. Harmaline and 5-HT2a receptor activation also increase IO coupling and CS synchrony and induce tremor. The hotfoot17 mouse displays features found in ET brains, including cerebellar GluRδ2 deficiency and abnormal PC Cf innervation, with IO- and PC-dependent cerebellar oscillations and tremor likely due to enhanced CS synchrony. Heightened coupling within the IO oscillator leads, through its dynamic control of CS synchrony, to increased movement amplitude and, when sufficiently intense, action tremor. Increased CS synchrony secondary to aberrant Cf innervation of multiple PCs likely also underlies hotfoot17 tremor. Deep cerebellar nucleus (DCN) hypersynchrony may occur secondary to increased CS synchrony but might also occur from PC axonal terminal sprouting during partial PC loss. Through these combined mechanisms, increased CS/DCN synchrony may plausibly underlie syndromic ET.
Collapse
Affiliation(s)
- Adrian Handforth
- Neurology Service, Veterans Affairs Greater Los Angeles Healthcare System, 11301 Wilshire Blvd., Los Angeles, CA, 90073, USA.
| | - Eric J Lang
- Department of Neuroscience and Physiology, New York University, School of Medicine, New York, NY, USA
| |
Collapse
|
20
|
Tapper S, Göransson N, Lundberg P, Tisell A, Zsigmond P. A pilot study of essential tremor: cerebellar GABA+/Glx ratio is correlated with tremor severity. CEREBELLUM & ATAXIAS 2020; 7:8. [PMID: 32607248 PMCID: PMC7318770 DOI: 10.1186/s40673-020-00116-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/29/2020] [Indexed: 12/16/2022]
Abstract
Objective Essential tremor is a common movement disorder with an unclear origin. Emerging evidence suggests the role of the cerebellum and the thalamus in tremor pathophysiology. We examined the two main neurotransmitters acting inhibitory (GABA+) and excitatory (Glx) respectively, in the thalamus and cerebellum, in patients diagnosed with severe essential tremor. Furthermore, we also investigated the relationship between determined neurotransmitter concentrations and tremor severity in the essential tremor patients. Methods Ten essential tremor patients (prior to deep brain stimulation surgery) and six healthy controls, were scanned using a 3 T MR system. GABA+ and Glx concentrations were measured using magnetic resonance spectroscopy (MRS) performed using single voxel MEGA-PRESS. For the purpose of assessing the tremor severity, the essential tremor rating scale (ETRS) was used in accordance with Fahn, Tolosa, and Marin. Results We demonstrated that the cerebellar GABA+/Glx ratio was positively correlated to the ETRS (r = 0.70, p = 0.03) in essential tremor. Cerebellar and thalamic GABA+ and Glx concentrations did not show any significant difference when comparing essential tremor patients with healthy controls, at the group level. Conclusion We demonstrated a positive correlation between increasing tremor disability and the ratio of GABA+/ Glx in the cerebellum of essential tremor patients. This highlights the impact of an altered balance of the excitatory and inhibitory neurotransmitters in tremor severity. Rather than a change in GABA+, which was constant, we attribute this finding to an overall decrease of Glx.
Collapse
Affiliation(s)
- Sofie Tapper
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Medical Radiation Physics and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Nathanael Göransson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Peter Lundberg
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Medical Radiation Physics and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Anders Tisell
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Medical Radiation Physics and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Peter Zsigmond
- Department of Neurosurgery and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| |
Collapse
|
21
|
Saranza G, Fasano A. Excessive Cerebellar Oscillations in Essential Tremor: Insights Into Disease Mechanism and Treatment. Mov Disord 2020; 35:758. [PMID: 32239538 DOI: 10.1002/mds.28040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 03/07/2020] [Accepted: 03/09/2020] [Indexed: 12/20/2022] Open
Affiliation(s)
- Gerard Saranza
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Centre, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Alfonso Fasano
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Centre, Toronto Western Hospital, Toronto, Ontario, Canada.,Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.,Krembil Brain Institute, Toronto, Ontario, Canada.,CenteR for Advancing Neurotechnological Innovation to Application (CRANIA), Toronto, Ontario, Canada
| |
Collapse
|
22
|
Essential tremor pathology: neurodegeneration and reorganization of neuronal connections. Nat Rev Neurol 2020; 16:69-83. [PMID: 31959938 DOI: 10.1038/s41582-019-0302-1] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2019] [Indexed: 01/26/2023]
Abstract
Essential tremor (ET) is the most common tremor disorder globally and is characterized by kinetic tremor of the upper limbs, although other clinical features can also occur. Postmortem studies are a particularly important avenue for advancing our understanding of the pathogenesis of ET; however, until recently, the number of such studies has been limited. Several recent postmortem studies have made important contributions to our understanding of the pathological changes that take place in ET. These studies identified abnormalities in the cerebellum, which primarily affected Purkinje cells (PCs), basket cells and climbing fibres, in individuals with ET. We suggest that some of these pathological changes (for example, focal PC axonal swellings, swellings in and regression of the PC dendritic arbor and PC death) are likely to be primary and degenerative. By contrast, other changes, such as an increase in PC recurrent axonal collateral formation and hypertrophy of GABAergic basket cell axonal processes, could be compensatory responses to restore cerebellar GABAergic tone and cerebellar cortical inhibitory efficacy. Such compensatory responses are likely to be insufficient, enabling the disease to progress. Here, we review the results of recent postmortem studies of ET and attempt to place these findings into an anatomical-physiological disease model.
Collapse
|
23
|
Zhang M, Li W, Hu L, Chen L, Yang L, Zhang T, Shen H, Peng Y, Gao S, Chen Z, Wang T, Zhao Z. Oral propranolol for treatment of the subgroups of essential tremor: a systematic review and meta-analysis protocol. BMJ Open 2020; 10:e032096. [PMID: 31948986 PMCID: PMC7044890 DOI: 10.1136/bmjopen-2019-032096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/21/2019] [Accepted: 12/04/2019] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Essential tremor (ET), a tremor disorder, is one of the most common movement disorders. Only oral drugs (propranolol, primidone, topiramate, etc)are still the first-line treatment recommended by the Food and Drug Administration. Propranolol is thought to potentially reduce upper limb action tremor. However, it has a poor effect on axial tremor symptoms, such as essential head tremor and voice tremor. Studies have shown that tremor severity develops over time, possibly producing other clinical tremors and neurological soft signs (such as memory loss, gait abnormalities, balance disorders, etc), which further increases the difficulty of treating tremors. However, some recent studies provide emerging evidence for oral propranolol on subgroups of ET, which is based on the anatomical distribution of ET (lower extremities, head, sound, tongue, etc). This systematic review aims to synthesise these new data to improve the efficacy of propranolol in ET subgroups. METHODS AND ANALYSIS We will search for randomised controlled trials from the PubMed, MEDLINE, EMBASE, Cochrane Library, UptoDate and PEDro databases from inception to June 2019. All data will be extracted independently by two reviewers and compared at the end of the review. The two reviewers will screen the study quality, and the Cochrane Collaboration's tool in Review Manager (RevMan) V.5.3.3 will be used to evaluate risk of bias. Our primary outcome will be the functional disability component related to tremors, as measured by the Fahn-Tolosa-Marin Tremor Rating Scale subscales B and C. Secondary outcomes will include severity of tremors and quality of life. Narrative and meta-analytical syntheses are planned. ETHICS AND DISSEMINATION Published aggregated data will be used in this review analysis and therefore no ethical approval is required. The results will be published in peer-reviewed journals, and proliferation activities will include diverse social stakeholders, non-academic groups and patients. PROSPERO REGISTRATION NUMBER CRD42018112580.
Collapse
Affiliation(s)
- Manyu Zhang
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Wei Li
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Lan Hu
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Li Chen
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Liu Yang
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Tian Zhang
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Hui Shen
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Yanan Peng
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Shijun Gao
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Zhibin Chen
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Tan Wang
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| | - Zhenqiang Zhao
- Department of Neurology, First Affiliated Hospital, Hainan Medical University, Haikou, Hainan, China
| |
Collapse
|
24
|
Kuo SH, Louis ED, Faust PL, Handforth A, Chang SY, Avlar B, Lang EJ, Pan MK, Miterko LN, Brown AM, Sillitoe RV, Anderson CJ, Pulst SM, Gallagher MJ, Lyman KA, Chetkovich DM, Clark LN, Tio M, Tan EK, Elble RJ. Current Opinions and Consensus for Studying Tremor in Animal Models. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1036-1063. [PMID: 31124049 PMCID: PMC6872927 DOI: 10.1007/s12311-019-01037-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tremor is the most common movement disorder; however, we are just beginning to understand the brain circuitry that generates tremor. Various neuroimaging, neuropathological, and physiological studies in human tremor disorders have been performed to further our knowledge of tremor. But, the causal relationship between these observations and tremor is usually difficult to establish and detailed mechanisms are not sufficiently studied. To overcome these obstacles, animal models can provide an important means to look into human tremor disorders. In this manuscript, we will discuss the use of different species of animals (mice, rats, fruit flies, pigs, and monkeys) to model human tremor disorders. Several ways to manipulate the brain circuitry and physiology in these animal models (pharmacology, genetics, and lesioning) will also be discussed. Finally, we will discuss how these animal models can help us to gain knowledge of the pathophysiology of human tremor disorders, which could serve as a platform towards developing novel therapies for tremor.
Collapse
Affiliation(s)
- Sheng-Han Kuo
- Department of Neurology, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA.
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 800 Howard Avenue, Ste Lower Level, New Haven, CT, 06519, USA.
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA.
- Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Adrian Handforth
- Neurology Service, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Su-Youne Chang
- Department of Neurologic Surgery and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Billur Avlar
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Eric J Lang
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Ming-Kai Pan
- Department of Medical Research and Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lauren N Miterko
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
| | - Amanda M Brown
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Collin J Anderson
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | | | - Kyle A Lyman
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Lorraine N Clark
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 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
| | - Murni Tio
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Rodger J Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
| |
Collapse
|
25
|
Martuscello RT, Kerridge CA, Chatterjee D, Hartstone WG, Kuo SH, Sims PA, Louis ED, Faust PL. Gene expression analysis of the cerebellar cortex in essential tremor. Neurosci Lett 2019; 721:134540. [PMID: 31707044 DOI: 10.1016/j.neulet.2019.134540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/28/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023]
Abstract
Essential tremor (ET) is one of the most common neurological diseases, with a central feature of an 8-12 Hz kinetic tremor. While previous postmortem studies have identified a cluster of morphological changes in the ET cerebellum centered in/around the Purkinje cell (PC) population, including a loss of PCs in some studies, the underlying molecular mechanisms for these changes are not clear. As genomic studies of ET patients have yet to identify major genetic contributors and animal models that fully recapitulate the human disease do not yet exist, the study of human tissue is currently the most applicable method to gain a mechanistic insight into ET disease pathogenesis. To begin exploration of an underlying molecular source of ET disease pathogenesis, we have performed the first transcriptomic analysis by direct sequencing of RNA from frozen cerebellar cortex tissue in 33 ET patients compared to 21 normal controls. Principal component analysis showed a heterogenous distribution of the expression data in ET patients that only partially overlapped with control patients. Differential expression analysis identified 231 differentially expressed gene transcripts ('top gene hits'), a subset of which has defined expression profiles in the cerebellum across neuronal and glial cell types but a largely unknown relationship to cerebellar function and/or ET pathogenesis. Gene set enrichment analysis (GSEA) identified dysregulated pathways of interest and stratified dysregulation among ET cases. By GSEA and mining curated databases, we compiled major categories of dysregulated processes and clustered string networks of known interacting proteins. Here we demonstrate that these 'top gene hits' contribute to regulation of four main biological processes, which are 1) axon guidance, 2) microtubule motor activity, 3) endoplasmic reticulum (ER) to Golgi transport and 4) calcium signaling/synaptic transmission. The results of our transcriptomic analysis suggest there is a range of different processes involved among ET cases, and draws attention to a particular set of genes and regulatory pathways that provide an initial platform to further explore the underlying biology of ET.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Chloë A Kerridge
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Debotri Chatterjee
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Sheng-Han Kuo
- College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 W 168th Street, BB302, New York, NY, USA.
| | - Peter A Sims
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 W 168th Street, BB302, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, 3960 Broadway, RM208, New York, NY, USA; Sulzberger Columbia Genome Center, Columbia University Medical Center, 1150 St. Nicholas Ave., New York, NY, USA; Department of Biochemistry & Molecular Biophysics, Columbia University Medical Center, 701 W 168th Street, New York, NY, USA.
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, New Haven, CT, USA; Department of Chronic Disease Epidemiology, Yale School of Public Health, 15 York Street, Yale University, New Haven, CT, USA; Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, 15 York Street, New Haven, CT, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| |
Collapse
|
26
|
Becktepe JS, Gövert F, Kasiske L, Yalaz M, Witt K, Deuschl G. Pupillary response to light and tasks in early and late onset essential tremor patients. Parkinsonism Relat Disord 2019; 66:62-67. [PMID: 31327629 DOI: 10.1016/j.parkreldis.2019.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/23/2019] [Accepted: 07/05/2019] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Late-onset essential tremor is characterised by shorter life expectancy and more advanced aging parameters and may therefore be an 'aging-related' tremor. Brainstem functions involved in pupillary responses are hypothesized to reflect such earlier aging. The pupillary light response (PLR) and a task evoked pupillary response (TEPR) were used to test this hypothesis in same-aged patients with early onset (EOET) and late onset (LOET) essential tremor and healthy controls. SUBJECTS AND METHODS Age related changes of the PLR and TEPR during the paced auditory serial addition test (PASAT) were tested in 57 normal subjects. Subsequently, 13 patients with LOET and 16 patients with EOET were compared with 15 age matched healthy controls. Standard parameters of PLR were recorded, amongst others the time to maximum acceleration of the PLR (T1) and the time to maximum velocity (T2). The TEPR was determined during the PASAT as the percentage change in pupil size (PCPS). Data were analysed with ANOVA and post-hoc testing. RESULTS In normal subjects the pupil diameter, latency, maximum acceleration/velocity and percentage amplitude were correlated with age. Latency of the pupillary light response was significantly longer in LOET compared to controls and EOET while no differences were found between EOET and controls. The TEPR showed no significant differences between the three groups. CONCLUSION LOET showed a prolonged latency of the PLR compared to EOET possibly indicating premature aging or rather pathophysiological differences on brainstem level. This study further supports the hypothesis of abnormal aging in LOET.
Collapse
Affiliation(s)
- Jos S Becktepe
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany
| | - Felix Gövert
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany
| | - Lisa Kasiske
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany
| | - Mevlüt Yalaz
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany
| | - Karsten Witt
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany; Department of Neurology and Research Center Neurosensory Science, Carl von Ossietzky University, 26122, Oldenburg, Germany
| | - Günther Deuschl
- Department of Neurology, University Hospital Schleswig Holstein, 24105, Kiel, Germany.
| |
Collapse
|
27
|
Neuropathology and pathogenesis of extrapyramidal movement disorders: a critical update. II. Hyperkinetic disorders. J Neural Transm (Vienna) 2019; 126:997-1027. [DOI: 10.1007/s00702-019-02030-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 06/14/2019] [Indexed: 12/14/2022]
|
28
|
Tarakad A, Jankovic J. Essential Tremor and Parkinson's Disease: Exploring the Relationship. Tremor Other Hyperkinet Mov (N Y) 2019; 8:589. [PMID: 30643667 PMCID: PMC6329774 DOI: 10.7916/d8md0gvr] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/04/2018] [Indexed: 12/31/2022] Open
Abstract
Background There is longstanding controversy surrounding the possible link between essential tremor (ET) and Parkinson's disease (PD). Inconsistent and unreliable diagnostic criteria may in part account for some of the difficulties in defining the relationship between these two common movement disorders. Methods References for this systematic review were identified using PubMed with the search terms "essential tremor" AND "Parkinson's disease" with articles published in English between 1960 and September 2018 included. Results In this review we provide evidence that some patients diagnosed with ET have an increased risk of developing PD years or decades after onset of action tremor. There are several still unresolved questions about the link between the two disorders including lack of verifiable diagnostic criteria for the two disorders and marked overlap in phenomenology. Here we review clinical, epidemiologic, imaging, pathologic, and genetic studies that address the ET-PD relationship. Several lines of evidence support the association between ET and PD, including overlapping motor and non-motor features, relatively high prevalence of rapid eye movement sleep behavior disorder (26-43%) in ET patients, increased prevalence of PD in patients with longstanding antecedent ET, increased prevalence of ET in family members of patients with PD, and the presence of Lewy bodies in the brains of some ET patients (15-24%). Discussion There is a substantial body of evidence supporting the association between ET and PD within at least a subset of patients, although the nature and possible pathogenic mechanisms of the relationship are not well understood.
Collapse
Affiliation(s)
- Arjun Tarakad
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
| | - Joseph Jankovic
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
| |
Collapse
|
29
|
Pan MK, Ni CL, Wu YC, Li YS, Kuo SH. Animal Models of Tremor: Relevance to Human Tremor Disorders. Tremor Other Hyperkinet Mov (N Y) 2018; 8:587. [PMID: 30402338 PMCID: PMC6214818 DOI: 10.7916/d89s37mv] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/10/2018] [Indexed: 12/17/2022] Open
Abstract
Background Tremor is the most common movement disorder; however, the pathophysiology of tremor remains elusive. While several neuropathological alterations in tremor disorders have been observed in post-mortem studies of human brains, a full understanding of the relationship between brain circuitry alterations and tremor requires testing in animal models. Additionally, tremor animal models are critical for our understanding of tremor pathophysiology, and/or to serve as a platform for therapy development. Methods A PubMed search was conducted in May 2018 to identify published papers for review. Results The methodology used in most studies on animal models of tremor lacks standardized measurement of tremor frequency and amplitude; instead, these studies are based on the visual inspection of phenotypes, which may fail to delineate tremor from other movement disorders such as ataxia. Of the animal models with extensive tremor characterization, harmaline-induced rodent tremor models provide an important framework showing that rhythmic and synchronous neuronal activities within the olivocerebellar circuit can drive action tremor. In addition, dopamine-depleted monkey and mouse models may develop rest tremor, highlighting the role of dopamine in rest tremor generation. Finally, other animal models of tremor have involvement of the cerebellar circuitry, leading to altered Purkinje cell physiology. Discussion Both the cerebellum and the basal ganglia are likely to play a role in tremor generation. While the cerebellar circuitry can generate rhythmic movements, the nigrostriatal system is likely to modulate the tremor circuit. Tremor disorders are heterogeneous in nature. Therefore, each animal model may represent a subset of tremor disorders, which collectively can advance our understanding of tremor.
Collapse
Affiliation(s)
- Ming-Kai Pan
- Department of Medical Research, National Taiwan University, Taipei, TW
| | - Chun-Lun Ni
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Yeuh-Chi Wu
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Yong-Shi Li
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| |
Collapse
|