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Cui JG, Zhang H, Chen MS, Wang JX, Zhao Y, Li JL. Calcium homeostasis imbalance mediates DEHP induced mitochondrial damage in cerebellum and the antagonistic effect of lycopene. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176351. [PMID: 39299314 DOI: 10.1016/j.scitotenv.2024.176351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/25/2024] [Accepted: 09/16/2024] [Indexed: 09/22/2024]
Abstract
Phthalates (PAEs), especially di (2-ethylhexyl) phthalate (DEHP), are generally considered to have adverse impact on nervous system. The residue of DEHP in the environment has gradually become a widely concerned environmental problem due to its widespread use in plastic items. Lycopene (LYC) as the readily available natural antioxidant is considered to have the potential to alleviate exogenous poisons-induced nerve damage. However, there is currently a lack of strategies to alleviate the neurotoxicity caused by DEHP, and it is also unknown whether LYC can alleviate the neurotoxicity caused by DEHP. The experiment demonstrated that LYC had the potential to mitigate DEHP-induced mitochondrial damage in cerebellum. DEHP induced the disorder of Ca2+ transport in cerebellum, thereby resulting in the imbalance of protein homeostasis. Such disruption in protein homeostasis further results in the overactivation of mitochondrial unfolded protein response (UPRmt) and mitochondrial injury. Mechanistically, LYC could alleviate the imbalance of calcium homeostasis and protein homeostasis induced by DEHP via regulating inositol 1, 4, 5-trisphosphate receptor type1 (IP3R1) and sarco/endoplasmic reticulum Ca (2+)-ATPase 2 (SERCA2), further alleviating mitochondrial damage in cerebellum. Subsequently, the present study suggested the mechanism of cerebellar injury induced by DEHP, and provided a novel approach to treating DEHP-induced neurotoxicity.
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Affiliation(s)
- Jia-Gen Cui
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China
| | - Hao Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China
| | - Ming-Shan Chen
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China
| | - Jia-Xin Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China
| | - Yi Zhao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin 150030, PR China.
| | - Jin-Long Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin 150030, PR China.
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Louis ED, Kuo SH, Faust PL. Purkinje Cell Dendritic Swellings: A Postmortem Study of Essential Tremor and Other Cerebellar Degenerative Disorders. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01739-1. [PMID: 39230844 DOI: 10.1007/s12311-024-01739-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/27/2024] [Indexed: 09/05/2024]
Abstract
Under stress, Purkinje cells (PCs) undergo a variety of reactive morphological changes. These can include swellings of neuronal processes. While axonal swellings, "torpedoes", have been well-studied, dendritic swellings (DS) have not been the centerpiece of study. Surprisingly little is known about their frequency or relationship to other morphological changes in degenerating PCs. Leveraging a large brain bank, we (1) examined the morphology of DS, (2) quantified DS, and (2) examined correlations between counts of DS versus 16 other PC morphological changes in a broad range of cerebellar degenerative disorders. There were 159 brains - 100 essential tremor (ET), 13 Friedreich's ataxia, and 46 spinocerebellar ataxia (SCA) (14 SCA1, 7 SCA2, 13 SCA3, 5 SCA6, 5 SCA7, and 2 SCA8). DS were a feature of PCs across all these disorders, with varying morphologies and changes elsewhere in the dendritic arbor. On Luxol fast blue/hematoxylin and eosin-stained sections, the median number of DS per PC ranged from 0.001 in ET to 0.025 in SCA8. Bielschowsky-stained sections yielded higher counts, from 0.003 in ET to 0.042 in SCA6. Torpedo counts exceeded DS counts by one order of magnitude. DS counts were more robustly correlated with torpedo counts than with counts for any of the other PC morphological changes. In summary, DS ranged in prevalence across cerebellar degenerative disorders, from 1/1,000 to 42/1,000 PCs. Across disorders of cerebellar degeneration, these swellings of the dendritic compartment were most robustly correlated with swellings of the axonal compartment, suggesting a similar type of cellular response to duress.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX, 75390-8813, USA.
- Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY, USA
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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.
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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
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Ruff DS, Balbo I, Lai R, Dieng D, Hennessey C, Vennam K, Dwork AJ, McCreary M, Louis ED, Faust PL, Kuo S. Reduced Bergmann glial process terminations and lateral appendages in essential tremor. Ann Clin Transl Neurol 2024; 11:377-388. [PMID: 38098226 PMCID: PMC10863904 DOI: 10.1002/acn3.51958] [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: 06/14/2023] [Revised: 10/29/2023] [Accepted: 11/12/2023] [Indexed: 02/15/2024] Open
Abstract
OBJECTIVE Postmortem examination of the essential tremor cerebellum has revealed a variety of pathological changes centered in and around Purkinje cells. Studies have predominantly focused on cerebellar neuronal connections. Bergmann glial morphology has not yet been studied in essential tremor. Among their many roles, Bergmann glia in the cerebellar cortex ensheath Purkinje cell synapses and provide neuroprotection. Specifically, the complex radial processes and lateral appendages of Bergmann glia are structural domains that modulate Purkinje cell synaptic transmission. In this study, we investigate whether Bergmann glia morphology is altered in the essential tremor cerebellum. METHODS We applied the Golgi-Kopsch method and used computerized three-dimensional cell reconstruction to visualize Bergmann glia in the postmortem cerebellum of 34 cases and 17 controls. We quantified morphology of terminal structures (number of terminations and lateral appendage density) and morphology of radial processes (total process length, branch length, branch order, and branch volume) in each glial cell. We quantified number of branches and volume as well. RESULTS Essential tremor cases had a 31.9% decrease in process terminations and a 35.7% decrease in lateral appendage density in Bergmann glia. Total process length and branch length did not differ between essential tremor cases and controls. We found also a reduction in number of secondary and tertiary branches and tertiary branches volume. INTERPRETATION These findings suggest that Bergmann glia in essential tremor cases have more alterations in their terminal structures, with a relative preservation of radial processes, and highlight a potential role for these astrocytes in the disease pathophysiology.
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Affiliation(s)
- David S. Ruff
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Ilaria Balbo
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Ruo‐Yah Lai
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Diarra Dieng
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Charlotte Hennessey
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Krish Vennam
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
| | - Andrew J. Dwork
- Department of Pathology and Cell BiologyColumbia University Medical Center, The New York Presbyterian HospitalNew YorkNew York10032USA
- Department of PsychiatryColumbia UniversityNew YorkNew YorkUSA
| | - Morgan McCreary
- Department of NeurologyUniversity of Texas SouthwesternDallasTexas75390USA
| | - Elan D. Louis
- Department of NeurologyUniversity of Texas SouthwesternDallasTexas75390USA
| | - Phyllis L. Faust
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
- Department of Pathology and Cell BiologyColumbia University Medical Center, The New York Presbyterian HospitalNew YorkNew York10032USA
| | - Sheng‐Han Kuo
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
- Initiative for Columbia Ataxia and TremorColumbia UniversityNew YorkNew York10032USA
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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.
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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.
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Shushanyan R, Grigoryan A, Abgaryan T, Karapetyan A. Histological and cytochemical analysis of the brain under conditions of hypobaric hypoxia-induced oxygen deficiency in albino rats. Acta Histochem 2023; 125:152114. [PMID: 37980852 DOI: 10.1016/j.acthis.2023.152114] [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: 06/25/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/21/2023]
Abstract
High altitude sickness is a life-threatening disease that occurs among acclimatized individuals working or living at a high altitude accompanied by hypobaric hypoxia exposure. The prolonged influence of hypobaric hypoxia on the brain may trigger neuronal damage and cell death due to an oxygen deficiency. The purpose of the current study was to investigate the histomorphological changes in the hippocampus, cerebral cortex, cerebellar cortex, and striatum of the rat's brain following chronic hypobaric hypoxia. Fourteen albino rats were used for this investigation. The animals were exposed to chronic hypobaric hypoxia in the special decompression chamber at an altitude of 7000 m for 7 days. The histological analysis was conducted via toluidine staining and silver impregnation. DNA damage and cell apoptosis were assessed via Feulgen staining. The histochemical assessment revealed increased dark neurons in the hippocampus with cell swelling. Silver impregnation showed increased argyrophilic neurons in the cerebellar cortex, striatum, CA1 subfield of the hippocampus, and cerebral cortex. The cytochemical analysis determined the increased apoptotic cells with hyperchromatic condensation and pyknosis in the hippocampus subfields and cerebral cortex. In addition, it has been observed that hypoxia has resulted in small hemorrhages and perivascular edema within the cerebellar and cerebral cortex. The results indicate brain injury observed in the various parts of the brain towards hypobaric hypoxia, however, the hippocampus showed greater vulnerability against hypoxic exposure in comparison to the striatum, cerebellum, and cerebral cortex. These changes support our insights regarding brain intolerance under conditions of hypoxia-induced oxygen deficiency and its histomorphological manifestations.
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Affiliation(s)
- Ruzanna Shushanyan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Anna Grigoryan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Tamara Abgaryan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Anna Karapetyan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
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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.
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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.
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Baumel Y, Yamin HG, Cohen D. Chemical suppression of harmaline-induced body tremor yields recovery of pairwise neuronal coherence in cerebellar nuclei neurons. Front Syst Neurosci 2023; 17:1135799. [PMID: 37251003 PMCID: PMC10211344 DOI: 10.3389/fnsys.2023.1135799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
Neuronal oscillations occur in health and disease; however, their characteristics can differ across conditions. During voluntary movement in freely moving rats, cerebellar nuclei (CN) neurons display intermittent but coherent oscillations in the theta frequency band (4-12 Hz). However, in the rat harmaline model of essential tremor, a disorder attributed to cerebellar malfunction, CN neurons display aberrant oscillations concomitantly with the emergence of body tremor. To identify the oscillation features that may underlie the emergence of body tremor, we analyzed neuronal activity recorded chronically from the rat CN under three conditions: in freely behaving animals, in harmaline-treated animals, and during chemical suppression of the harmaline-induced body tremor. Suppression of body tremor did not restore single neuron firing characteristics such as firing rate, the global and local coefficients of variation, the likelihood of a neuron to fire in bursts or their tendency to oscillate at a variety of dominant frequencies. Similarly, the fraction of simultaneously recorded neuronal pairs oscillating at a similar dominant frequency (<1 Hz deviation) and the mean frequency deviation within pairs remained similar to the harmaline condition. Moreover, the likelihood that pairs of CN neurons would co-oscillate was not only significantly lower than that measured in freely moving animals, but was significantly worse than chance. By contrast, the chemical suppression of body tremor fully restored pairwise neuronal coherence; that is, unlike in the harmaline condition, pairs of neurons that oscillated at the same time and frequency displayed high coherence, as in the controls. We suggest that oscillation coherence in CN neurons is essential for the execution of smooth movement and its loss likely underlies the emergence of body tremor.
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Affiliation(s)
| | | | - Dana Cohen
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
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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.
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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.
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Louis ED, Martuscello RT, Gionco JT, Hartstone WG, Musacchio JB, Portenti M, McCreary M, Kuo SH, Vonsattel JPG, Faust PL. Histopathology of the cerebellar cortex in essential tremor and other neurodegenerative motor disorders: comparative analysis of 320 brains. Acta Neuropathol 2023; 145:265-283. [PMID: 36607423 PMCID: PMC10461794 DOI: 10.1007/s00401-022-02535-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/14/2022] [Accepted: 12/22/2022] [Indexed: 01/07/2023]
Abstract
In recent years, numerous morphologic changes have been identified in the essential tremor (ET) cerebellar cortex, distinguishing ET from control brains. These findings have not been fully contextualized within a broader degenerative disease spectrum, thus limiting their interpretability. Building off our prior study and now doubling the sample size, we conducted comparative analyses in a postmortem series of 320 brains on the severity and patterning of cerebellar cortex degenerative changes in ET (n = 100), other neurodegenerative disorders of the cerebellum [spinocerebellar ataxias (SCAs, n = 47, including 13 SCA3 and 34 SCA1, 2, 6, 7, 8, 14); Friedreich's ataxia (FA, n = 13); multiple system atrophy (MSA), n = 29], and other disorders that may involve the cerebellum [Parkinson's disease (PD), n = 62; dystonia, n = 19] versus controls (n = 50). We generated data on 37 quantitative morphologic metrics, grouped into 8 broad categories: Purkinje cell (PC) loss, heterotopic PCs, PC dendritic changes, PC axonal changes (torpedoes), PC axonal changes (other than torpedoes), PC axonal changes (torpedo-associated), basket cell axonal hypertrophy, and climbing fiber-PC synaptic changes. Principal component analysis of z scored raw data across all diagnoses (11,651 data items) revealed that diagnostic groups were not uniform with respect to pathology. Dystonia and PD each differed from controls in only 4/37 and 5/37 metrics, respectively, whereas ET differed in 21, FA in 10, SCA3 in 10, MSA in 21, and SCA1/2/6/7/8/14 in 27. Pathological changes were generally on the milder end of the degenerative spectrum in ET, FA and SCA3, and on the more severe end of that spectrum in SCA1/2/6/7/8/14. Comparative analyses across morphologic categories demonstrated differences in relative expression, defining distinctive patterns of changes in these groups. In summary, we present a robust and reproducible method that identifies somewhat distinctive signatures of degenerative changes in the cerebellar cortex that mark each of these disorders.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX, 75390-8813, USA.
| | - Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - John T Gionco
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Jessica B Musacchio
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Marisa Portenti
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Morgan McCreary
- Department of Neurology, University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX, 75390-8813, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jean-Paul G Vonsattel
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
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11
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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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12
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Upper Limb Function but Not Proprioception is Impaired in Essential Tremor: A Between-Groups Study and Causal Mediation Analysis. Tremor Other Hyperkinet Mov (N Y) 2023; 13:1. [PMID: 36644368 PMCID: PMC9818046 DOI: 10.5334/tohm.731] [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] [Received: 10/24/2022] [Accepted: 12/19/2022] [Indexed: 01/04/2023] Open
Abstract
Background Essential tremor (ET) is characterized by abnormal oscillatory muscle activity and cerebellar involvement, factors that can lead to proprioceptive deficits, especially in active tasks. The present study aimed to quantify the severity of proprioceptive deficits in people with ET and estimate how these contribute to functional impairments. Methods Upper limb sensory, proprioceptive and motor function was assessed inindividuals with ET (n = 20) and healthy individuals (n = 22). To measure proprioceptive ability, participants discriminated the width of grasped objects and the weight of objects liftedwith the wrist extensors. Causal mediation analysis was used to estimate the extentthat impairments in upper limb function in ET was mediated by proprioceptive ability. Results Participants with ET had impaired upper limb function in all outcomes, and had greater postural and kinetic tremor. There were no differences between groups in proprioceptive discrimination of width (between-group mean difference [95% CI]: 0.32 mm [-0.23 to 0.87 mm]) or weight (-1.12 g [-7.31 to 5.07 g]). Causal mediation analysis showed the effect of ET on upper limb function was not mediated by proprioceptive ability. Conclusions Upper limb function but not proprioception was impaired in ET. The effect of ET on motor function was not mediated by proprioception. These results indicate that the central nervous system of people with ET is able to accommodate mild to moderate tremor in active proprioceptive tasks that rely primarily on afferent signals from muscle spindles.
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13
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Zhou J, Van der Heijden ME, Salazar Leon LE, Lin T, Miterko LN, Kizek DJ, Perez RM, Pavešković M, Brown AM, Sillitoe RV. Propranolol Modulates Cerebellar Circuit Activity and Reduces Tremor. Cells 2022; 11:cells11233889. [PMID: 36497147 PMCID: PMC9740691 DOI: 10.3390/cells11233889] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/10/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
Tremor is the most common movement disorder. Several drugs reduce tremor severity, but no cures are available. Propranolol, a β-adrenergic receptor blocker, is the leading treatment for tremor. However, the in vivo circuit mechanisms by which propranolol decreases tremor remain unclear. Here, we test whether propranolol modulates activity in the cerebellum, a key node in the tremor network. We investigated the effects of propranolol in healthy control mice and Car8wdl/wdl mice, which exhibit pathophysiological tremor and ataxia due to cerebellar dysfunction. Propranolol reduced physiological tremor in control mice and reduced pathophysiological tremor in Car8wdl/wdl mice to control levels. Open field and footprinting assays showed that propranolol did not correct ataxia in Car8wdl/wdl mice. In vivo recordings in awake mice revealed that propranolol modulates the spiking activity of control and Car8wdl/wdl Purkinje cells. Recordings in cerebellar nuclei neurons, the targets of Purkinje cells, also revealed altered activity in propranolol-treated control and Car8wdl/wdl mice. Next, we tested whether propranolol reduces tremor through β1 and β2 adrenergic receptors. Propranolol did not change tremor amplitude or cerebellar nuclei activity in β1 and β2 null mice or Car8wdl/wdl mice lacking β1 and β2 receptor function. These data show that propranolol can modulate cerebellar circuit activity through β-adrenergic receptors and may contribute to tremor therapeutics.
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Affiliation(s)
- Joy Zhou
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meike E. Van der Heijden
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Luis E. Salazar Leon
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Lauren N. Miterko
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dominic J. Kizek
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Ross M. Perez
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Matea Pavešković
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Amanda M. Brown
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Roy V. Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-832-824-8913
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14
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Louis ED, Iglesias-Hernandez D, Hernandez NC, Flowers X, Kuo SH, Vonsattel JPG, Faust PL. Characterizing Lewy Pathology in 231 Essential Tremor Brains From the Essential Tremor Centralized Brain Repository. J Neuropathol Exp Neurol 2022; 81:796-806. [PMID: 35950950 PMCID: PMC9487643 DOI: 10.1093/jnen/nlac068] [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] [Indexed: 12/13/2022] Open
Abstract
The Essential Tremor Centralized Brain Repository is the largest repository of prospectively collected essential tremor (ET) brains (n = 231). Hence, we are uniquely poised to address several questions: What proportion of ET cases has Lewy pathology (LP)? What is the nature of that pathology and how does it relate to other comorbidities? Each brain had a complete neuropathological assessment, including α-synuclein immunostaining. We created a 10-category classification scheme to fully encapsulate the patterns of LP observed. Four metrics of cerebellar pathology were also quantified. Mean age at death = 89.0 ± 6.4 years. Fifty-eight (25.1%) had LP and 46 (19.9%) had early to late stages of Parkinson disease (PD). LP was very heterogeneous. Of 58 cases with LP, 14 (24.1%) clinically developed possible PD or PD after a latency of 5 or more years. There was a similar degree of cerebellar pathology in ET cases both with and without LP. In summary, 1 in 4 ET cases had LP-a proportion that seems higher than expected based on studies among control populations. Heterogeneous LP likely reflects clinical associations between ET and PD, and ET with Alzheimer disease-type neuropathology. These data further our understanding of ET and its relatedness to other degenerative diseases.
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Affiliation(s)
- Elan D Louis
- From the Department of Neurology, University of Texas Southwestern, Dallas, Texas, USA
| | | | - Nora C Hernandez
- From the Department of Neurology, University of Texas Southwestern, Dallas, Texas, USA
| | - Xena Flowers
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Jean Paul G Vonsattel
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
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15
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Wagle Shukla A. Reduction of neuronal hyperexcitability with modulation of T-type calcium channel or SK channel in essential tremor. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:335-355. [PMID: 35750369 DOI: 10.1016/bs.irn.2022.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Essential tremor is one of the most prevalent movement disorders. Propranolol and primidone are the first-line pharmacological therapies. They provide symptomatic control in less than 50% of patients. Topiramate, alprazolam, clonazepam, gabapentin, and botulinum toxin injections are the next line of treatments. These medications lead to modest improvements and are therefore commonly used as add-on agents. Surgical therapies, including deep brain stimulation (DBS) surgery and focused ultrasound beam targeted to the thalamus, are considered for treating tremor refractory to medications and lead to greater than 75% improvements in tremor symptoms. However, DBS is a costly and an invasive procedure; some patients report tolerance to benefits. Focused ultrasound therapy leading to brain lesions is associated with a possibility for permanent clinical deficits. Therefore, research efforts to develop the next generation of oral medications with greater benefits and lesser adverse effects are warranted. There is considerable evidence that the increased functions of calcium channels (P/Q-type and T-type channels) and reduced functions of calcium-activated potassium channels (SK channels) located in the neuronal membranes lead to tremor oscillations. Consequently, many new pharmacological studies have targeted these channels to leverage better clinical outcomes. The current review will discuss the pathophysiology, the specific importance of these channels, and the early clinical experience of using compounds targeting these channels to treat essential tremor.
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Affiliation(s)
- Aparna Wagle Shukla
- Department of Neurology, Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States.
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16
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Riboldi GM, Frucht SJ. Is essential tremor a family of diseases or a syndrome? A family of diseases. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:7-29. [PMID: 35750371 DOI: 10.1016/bs.irn.2022.02.001] [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: 06/15/2023]
Abstract
It is now well-established that essential tremor (ET) can manifest with different clinical presentations and progressions (i.e., upper limb tremor, head tremor, voice tremor, lower limb tremor, task- or position-specific tremor, or a combination of those). Common traits and overlaps are identifiable across these different subtypes of ET, including a slow rate of progression, a response to alcohol and a positive family history. At the same time, each of these manifestations are associated with specific demographic, clinical and treatment-response characteristics suggesting a family of diseases rather than a spectrum of a syndrome. Here we summarize the most important clinical, demographic, neuropathological and imagingfeatures of ET and of its subtypes to support ET as a family of identifiable conditions. This classification has relevance for counseling of patients with regard to disease progression and treatment response, as well as for the design of therapeutic clinical trials.
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Affiliation(s)
- Giulietta M Riboldi
- The Marlene and Paolo Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, United States
| | - Steven J Frucht
- The Marlene and Paolo Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, United States.
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17
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Manto M. Is inferior olive central to the pathophysiology of essential tremor? No. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:167-187. [PMID: 35750362 DOI: 10.1016/bs.irn.2022.02.010] [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
Essential tremor (ET) represents one of the commonest movement disorder worldwide and is the most common tremor disorder. ET manifests with various combinations of motor and nonmotor symptoms. The clinical hallmark is a kinetic tremor of upper limbs. Historically, the pathogenesis of ET has been based on the hypothesis of an overactivity of the inferior olive (inferior olive hypothesis: IOH) where the inferior olive would act as the central pace-maker of ET, resulting in impaired electrophysiological discharges of the olivo-cerebellar tract. The absence of structural alterations in post-mortem studies of the inferior olive is a striking argument against the IOH. Furthermore, neuroimaging studies point towards the implication of the cerebello-thalamo-cerebral pathway rather than the IO, and the harmaline model which has been considered as an animal model of ET presents important weaknesses. By contrast, a series of experiments by Louis et al. have provided convincing evidence of impaired wiring of the Purkinje cell microcircuitry and progressive neurodegeneration of the cerebellar cortex. The Purkinje neuron appears as the primary culprit (Purkinjopathy). The cerebellar cortex hypothesis (CCH) has solid neuropathological signatures, unlike the purely physiological IOH. Rather than a dysregulatory electrophysiological disorder suggested by IOH, ET is a clinical-pathological entity similar to late onset neurodegenerative disorders such as Parkinson's disease or Alzheimer's disease. The CCH emphasizes the need to develop novel therapeutic strategies in order to maintain or promote the cerebellar reserve. The modern reconceptualization of ET in a genuine cerebellar disorder is cleaning the IOH to the light of histopathological studies. ET falls in the large basket of the neurodegenerative diseases and we have entered into a novel formulation of the disease pathogenesis with direct impacts on future therapies.
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Affiliation(s)
- Mario Manto
- Unité des Ataxies Cérébelleuses, Service de Neurologie, CHU-Charleroi, Belgium; Service des Neurosciences, Université de Mons, Belgium.
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18
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Ondo W. Enhancing GABA inhibition is the next generation of medications for essential tremor. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:317-334. [PMID: 35750368 DOI: 10.1016/bs.irn.2022.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
γ-Aminobutyric acid (GABA) is the most prevalent inhibitory CNS neurotransmitter. Activating GABA-A receptors hyperpolarizes cells via Cl- influx, which inhibits action potentials. Although the exact pathophysiologies of tremor are incompletely understood, proposed neuroanatomy extensively implicates GABA pathways. Pathological studies and imaging studies also show GABA abnormalities in patients with ET. Most importantly, medications that activate GABA-A receptors, such as primidone, often improve tremor. Ongoing clinical trials and physiology research should further refine potential future GABAergic targets and treatments, which are currently the most promising targets for pharmacological intervention.
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Affiliation(s)
- William Ondo
- Houston Methodist Hospital, Weill Cornel Medical School, Houston, TX, United States.
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19
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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.
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20
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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.
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21
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Mavroudis I, Kazis D, Petridis F, Chatzikonstantinou S, Karantali E, Njau S, Costa V, Ciobica A, Trus C, Balmus I, Baloyannis S. Morphological and morphometric changes in the Purkinje cells of patients with essential tremor. Exp Ther Med 2021; 23:167. [PMID: 35069848 PMCID: PMC8753961 DOI: 10.3892/etm.2021.11090] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/30/2021] [Indexed: 11/09/2022] Open
Abstract
Essential tremor (ET) is a progressive neurological syndrome characterised by involuntary tremors of the hands or arms, head, jaw and voice. The pathophysiology of ET is not clearly understood yet. However, previous studies have reported several changes in the brain of patients with ET. One of the brain areas extensively investigated is the cerebellum. In the present study, a morphometric analysis of Purkinje cells in patients with ET and ET-plus was performed, and subsequently compared with normal controls using the Golgi silver staining method and 3D neuronal reconstruction. Substantial morphological changes were uncovered in the Purkinje cells of patients with ET compared with normal controls, including a decreased dendritic length and field density, an overall loss of terminal branches and a decreased density of dendritic spines.
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Affiliation(s)
- Ioannis Mavroudis
- Department of Neurology, Leeds Teaching Hospitals, NHS Trust, Leeds, LS1 3EX, United Kingdom
| | - Dimitrios Kazis
- Third Department of Neurology, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
| | - Foivos Petridis
- Third Department of Neurology, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
| | | | - Eleni Karantali
- Third Department of Neurology, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
| | - Samuel Njau
- Department of Forensic Medicine and Toxicology, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
| | - Vasiliki Costa
- Laboratory of Neuropathology and Electron Microscopy, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
| | - Alin Ciobica
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University, Iasi 700506, Romania
| | - Constantin Trus
- Department of Morphological and Functional Sciences, Faculty of Medicine, Dunarea de Jos University, Galati 800008, Romania
| | - Ioana Balmus
- Department of Exact Sciences and Natural Sciences, Institute of Interdisciplinary Research, Alexandru Ioan Cuza University of Iași, Iași 700057, Romania
| | - Stavros Baloyannis
- Laboratory of Neuropathology and Electron Microscopy, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
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22
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Kosmowska B, Wardas J. The Pathophysiology and Treatment of Essential Tremor: The Role of Adenosine and Dopamine Receptors in Animal Models. Biomolecules 2021; 11:1813. [PMID: 34944457 PMCID: PMC8698799 DOI: 10.3390/biom11121813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/25/2021] [Accepted: 11/30/2021] [Indexed: 12/13/2022] Open
Abstract
Essential tremor (ET) is one of the most common neurological disorders that often affects people in the prime of their lives, leading to a significant reduction in their quality of life, gradually making them unable to independently perform the simplest activities. Here we show that current ET pharmacotherapy often does not sufficiently alleviate disease symptoms and is completely ineffective in more than 30% of patients. At present, deep brain stimulation of the motor thalamus is the most effective ET treatment. However, like any brain surgery, it can cause many undesirable side effects; thus, it is only performed in patients with an advanced disease who are not responsive to drugs. Therefore, it seems extremely important to look for new strategies for treating ET. The purpose of this review is to summarize the current knowledge on the pathomechanism of ET based on studies in animal models of the disease, as well as to present and discuss the results of research available to date on various substances affecting dopamine (mainly D3) or adenosine A1 receptors, which, due to their ability to modulate harmaline-induced tremor, may provide the basis for the development of new potential therapies for ET in the future.
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Affiliation(s)
| | - Jadwiga Wardas
- Department of Neuropsychopharmacology, Maj Institute of Pharmacology Polish Academy of Sciences, 31-343 Kraków, Poland;
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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.
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24
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Neuropathology of blepharospasm. Exp Neurol 2021; 346:113855. [PMID: 34464652 DOI: 10.1016/j.expneurol.2021.113855] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/18/2021] [Accepted: 08/27/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND The dystonias are a group of disorders characterized by excessive muscle contractions leading to abnormal repetitive movements or postures. In blepharospasm, the face is affected, leading to excessive eye blinking and spasms of muscles around the eyes. The pathogenesis of blepharospasm is not well understood, but several imaging studies have implied subtle structural defects in several brain regions, including the cerebellum. OBJECTIVE To delineate cerebellar pathology in brains collected at autopsy from 7 human subjects with blepharospasm and 9 matched controls. METHODS Sections from 3 cerebellar regions were sampled and processed using Nissl and silver impregnation stains. Purkinje neurons were the focus of the evaluation, along with as several other subtle pathological features of cerebellar dysfunction such as Purkinje neuron axonal swellings (torpedo bodies), proliferation of basket cell processes around Purkinje neurons (hairy baskets), empty baskets (missing Purkinje neurons), and displacement of cell soma from their usual location (ectopic Purkinje neurons). RESULTS The results revealed a significant reduction in Purkinje neuron and torpedo body density, but no changes in any of the other measures. CONCLUSIONS These findings demonstrate subtle neuropathological changes similar to those reported for subjects with cervical dystonia. These findings may underly some of the subtle imaging changes reported for blepharospasm.
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25
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Louis ED, Faust PL. Essential Tremor Within the Broader Context of Other Forms of Cerebellar Degeneration. THE CEREBELLUM 2021; 19:879-896. [PMID: 32666285 DOI: 10.1007/s12311-020-01160-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Essential tremor (ET) has recently been reconceptualized by many as a degenerative disease of the cerebellum. Until now, though, there has been no attempt to frame it within the context of these diseases. Here, we compare the clinical and postmortem features of ET with other cerebellar degenerations, thereby placing it within the broader context of these diseases. Action tremor is the hallmark feature of ET. Although often underreported in the spinocerebellar ataxias (SCAs), action tremors occur, and it is noteworthy that in SCA12 and 15, they are highly prevalent, often severe, and can be the earliest disease manifestation, resulting in an initial diagnosis of ET in many cases. Intention tremor, sometimes referred to as "cerebellar tremor," is a common feature of ET and many SCAs. Other features of cerebellar dysfunction, gait ataxia and eye motion abnormalities, are seen to a mild degree in ET and more markedly in SCAs. Several SCAs (e.g., SCA5, 6, 14, and 15), like ET, follow a milder and more protracted disease course. In ET, numerous postmortem changes have been localized to the cerebellum and are largely confined to the cerebellar cortex, preserving the cerebellar nuclei. Purkinje cell loss is modest. Similarly, in SCA3, 12, and 15, Purkinje cell loss is limited, and in SCA12 and 15, there is preservation of cerebellar nuclei and relative sparing of other central nervous system regions. Both clinically and pathologically, there are numerous similarities and intersection points between ET and other disorders of cerebellar degeneration.
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Affiliation(s)
- Elan D Louis
- Department of Neurology and Therapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
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26
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Uyaroglu FG, Ucar R, Acarer A, Celebisoy N. What might cervical vestibular-evoked myogenic potential abnormalities mean in essential tremor? Neurol Sci 2021; 42:5271-5276. [PMID: 33860393 DOI: 10.1007/s10072-021-05248-5] [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: 11/18/2020] [Accepted: 04/10/2021] [Indexed: 10/21/2022]
Abstract
AIM/BACKGROUND Essential tremor (ET) is one of the most common movement disorders. However, its pathogenesis is unclear. Human vestibular reflexes are essential not only for gait and posture but also for goal-directed voluntary movements. In this study, cervical vestibular-evoked myogenic potentials (cVEMPs), the electrophysiological equivalent of the vestibulo-collic reflex was studied in ET patients to understand the interaction between the tremor network and the vestibular neural pathways. METHODS cVEMPs were recorded in 40 ET patients and 40 age and sex-matched healthy controls (HCs). The latencies of peaks p13 and n23 and peak-to-peak amplitude of p13-n23 were measured. RESULTS There was no statistically significant difference between the p13 latencies of the HC and ET groups (p 0.79 and p 0.23 for the right and left sides respectively). n23 latency was shortened bilaterally in the ET group (p 0.009 and p 0.02 for the right and left sides respectively). p13-n23 amplitudes of the ET patients were bilaterally reduced when compared with the HC (p <0.001 and p 0.001 for the right and left sides respectively). CONCLUSION Information provided by vestibular afferents is crucial in the control of voluntary movements in humans. Despite this silent but significant effect, the role of the vestibular system in movement disorders is often overlooked. In this study, it was found that cVEMP responses reflecting the activity of the vestibulo-collic pathway were affected in ET which can be either caused by dysfunctional structures or pathways responsible from ET or an additional disorder of vestibular information processing in these patients.
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Affiliation(s)
- Feray Gulec Uyaroglu
- Department of Neurology, Izmir Tepecik Education and Research Hospital, Izmir, Turkey
| | - Roza Ucar
- Department of Neurology, Izmir Tepecik Education and Research Hospital, Izmir, Turkey
| | - Ahmet Acarer
- Department of Neurology and Clinical Neurophysiology, Ege University Medical School, Bornova, 35100, Izmir, Turkey
| | - Nese Celebisoy
- Department of Neurology and Clinical Neurophysiology, Ege University Medical School, Bornova, 35100, Izmir, Turkey.
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27
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Stoyanov D. Biological Signatures of Disease in Neuro-Psychiatry as Inter-Theoretical Reduction. Curr Top Med Chem 2021; 20:746. [PMID: 32442080 DOI: 10.2174/156802662009200331084634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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28
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Hartstone WG, Brown MH, Kelly GC, Tate WJ, Kuo SH, Dwork AJ, Louis ED, Faust PL. Dentate Nucleus Neuronal Density: A Postmortem Study of Essential Tremor Versus Control Brains. Mov Disord 2020; 36:995-999. [PMID: 33258511 DOI: 10.1002/mds.28402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 10/26/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Essential tremor involves the cerebellum, yet quantitative analysis of dentate nucleus neurons has not been conducted. OBJECTIVES To quantitatively compare neuronal density or neuronal number in the dentate nucleus of essential tremor versus age-matched controls. METHODS Using a 7-μm thick Luxol fast blue hematoxylin and eosin-stained paraffin section, dentate nucleus neuronal density (neurons/mm2 ) was determined in 25 essential tremor cases and 25 controls. We also applied a stereological approach in a subset of four essential tremor cases and four controls to estimate total dentate nucleus neuronal number. RESULTS Dentate nucleus neuronal density did not differ between essential tremor cases and controls (P = 0.44). Total dentate nucleus neuronal number correlated with neuronal density (P = 0.007) and did not differ between essential tremor cases and controls (P = 0.95). CONCLUSIONS Neuronal loss, observed in the Purkinje cell population in essential tremor, did not seem to similarly involve the dentate nucleus in essential tremor. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Mark H Brown
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Geoffrey C Kelly
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - William J Tate
- Department of Pathology and Cell Biology, Columbia University Irving 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
| | - Andrew J Dwork
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA.,Department of Psychiatry, Columbia University, New York, New York, USA.,Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute New York, New York, New York, USA
| | - Elan D Louis
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, Texas, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
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29
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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.
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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
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30
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Zhou J, Brown AM, Lackey EP, Arancillo M, Lin T, Sillitoe RV. Purkinje cell neurotransmission patterns cerebellar basket cells into zonal modules defined by distinct pinceau sizes. eLife 2020; 9:55569. [PMID: 32990595 PMCID: PMC7561353 DOI: 10.7554/elife.55569] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 09/29/2020] [Indexed: 01/05/2023] Open
Abstract
Ramón y Cajal proclaimed the neuron doctrine based on circuit features he exemplified using cerebellar basket cell projections. Basket cells form dense inhibitory plexuses that wrap Purkinje cell somata and terminate as pinceaux at the initial segment of axons. Here, we demonstrate that HCN1, Kv1.1, PSD95 and GAD67 unexpectedly mark patterns of basket cell pinceaux that map onto Purkinje cell functional zones. Using cell-specific genetic tracing with an Ascl1CreERT2 mouse conditional allele, we reveal that basket cell zones comprise different sizes of pinceaux. We tested whether Purkinje cells instruct the assembly of inhibitory projections into zones, as they do for excitatory afferents. Genetically silencing Purkinje cell neurotransmission blocks the formation of sharp Purkinje cell zones and disrupts excitatory axon patterning. The distribution of pinceaux into size-specific zones is eliminated without Purkinje cell GABAergic output. Our data uncover the cellular and molecular diversity of a foundational synapse that revolutionized neuroscience.
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Affiliation(s)
- Joy Zhou
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States
| | - Amanda M Brown
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States
| | - Elizabeth P Lackey
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States
| | - Marife Arancillo
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States
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31
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Sailani MR, Jahanbani F, Abbott CW, Lee H, Zia A, Rego S, Winkelmann J, Hopfner F, Khan TN, Katsanis N, Müller SH, Berg D, Lyman KM, Mychajliw C, Deuschl G, Bernstein JA, Kuhlenbäumer G, Snyder MP. Candidate variants in TUB are associated with familial tremor. PLoS Genet 2020; 16:e1009010. [PMID: 32956375 PMCID: PMC7529431 DOI: 10.1371/journal.pgen.1009010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 10/01/2020] [Accepted: 07/24/2020] [Indexed: 11/19/2022] Open
Abstract
Essential tremor (ET) is the most common adult-onset movement disorder. In the present study, we performed whole exome sequencing of a large ET-affected family (10 affected and 6 un-affected family members) and identified a TUB p.V431I variant (rs75594955) segregating in a manner consistent with autosomal-dominant inheritance. Subsequent targeted re-sequencing of TUB in 820 unrelated individuals with sporadic ET and 630 controls revealed significant enrichment of rare nonsynonymous TUB variants (e.g. rs75594955: p.V431I, rs1241709665: p.Ile20Phe, rs55648406: p.Arg49Gln) in the ET cohort (SKAT-O test p-value = 6.20e-08). TUB encodes a transcription factor predominantly expressed in neuronal cells and has been previously implicated in obesity. ChIP-seq analyses of the TUB transcription factor across different regions of the mouse brain revealed that TUB regulates the pathways responsible for neurotransmitter production as well thyroid hormone signaling. Together, these results support the association of rare variants in TUB with ET. Essential tremor (ET) is the most common adult-onset movement disorder and in most affected families it appears to be inherited in an autosomal dominant pattern. The causes of essential tremor are unknown. Although many genetic studies in affected families and sporadic cases of ET have shown that genes may play a role, it has proven quite challenging to identify the specific genetic variants involved. Here, we use state-of-the-art technologies to identify the role of genetic variants on ET through exome sequencing of a large affected ET family and subsequent validation in a large population of cases and controls. We show that rare nonsynonymous variants of the TUB gene are significantly enriched in ET cases versus healthy controls. Further studies of biological pathways regulated by TUB in the mouse brain reveal key pathways related to ET. Our work expands our knowledge of the genetic basis of ET.
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Affiliation(s)
- M. Reza Sailani
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Fereshteh Jahanbani
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Charles W. Abbott
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Hayan Lee
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Amin Zia
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Shannon Rego
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, Technical University, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Franziska Hopfner
- Department of Neurology, Kiel University, Germany
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Tahir N. Khan
- Center for Human Disease Modeling, Duke University, United States of America
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University, United States of America
- Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital, Chicago, IL, United States of America
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | | | - Daniela Berg
- Department of Neurology, Kiel University, Germany
- Department of Neurology, Universitätsklinikum Tübingen, Germany
| | - Katherine M. Lyman
- Department of Genetics, Stanford University, Stanford, CA, United States of America
| | - Christian Mychajliw
- University Hospital Tübingen, Department of Psychiatry and Psychotherapy, Tübingen, Germany
| | | | - Jonathan A. Bernstein
- Department of Pediatrics, Stanford University, Stanford, CA, United States of America
| | | | - Michael P. Snyder
- Department of Genetics, Stanford University, Stanford, CA, United States of America
- * E-mail: (GK); (MPS)
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32
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Nietz A, Krook-Magnuson C, Gutierrez H, Klein J, Sauve C, Hoff I, Christenson Wick Z, Krook-Magnuson E. Selective loss of the GABA Aα1 subunit from Purkinje cells is sufficient to induce a tremor phenotype. J Neurophysiol 2020; 124:1183-1197. [PMID: 32902350 DOI: 10.1152/jn.00100.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Previously, an essential tremor-like phenotype has been noted in animals with a global knockout of the GABAAα1 subunit. Given the hypothesized role of the cerebellum in tremor, including essential tremor, we used transgenic mice to selectively knock out the GABAAα1 subunit from cerebellar Purkinje cells. We examined the resulting phenotype regarding impacts on inhibitory postsynaptic currents, survival rates, gross motor abilities, and expression of tremor. Purkinje cell specific knockout of the GABAAα1 subunit abolished all GABAA-mediated inhibition in Purkinje cells, while leaving GABAA-mediated inhibition to cerebellar molecular layer interneurons intact. Selective loss of GABAAα1 from Purkinje cells did not produce deficits on the accelerating rotarod, nor did it result in decreased survival rates. However, a tremor phenotype was apparent, regardless of sex or background strain. This tremor mimicked the tremor seen in animals with a global knockout of the GABAAα1 subunit, and, like essential tremor in patients, was responsive to ethanol. These findings indicate that reduced inhibition to Purkinje cells is sufficient to induce a tremor phenotype, highlighting the importance of the cerebellum, inhibition, and Purkinje cells in tremor.NEW & NOTEWORTHY Animals with a global knockout of the GABAAα1 subunit show a tremor phenotype reminiscent of essential tremor. Here we show that selective knockout of GABAAα1 from Purkinje cells is sufficient to produce a tremor phenotype, although this tremor is less severe than seen in animals with a global knockout. These findings illustrate that the cerebellum can play a key role in the genesis of the observed tremor phenotype.
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Affiliation(s)
- Angela Nietz
- University of Minnesota, Department of Neuroscience, Minneapolis, Minnesota
| | | | - Haruna Gutierrez
- University of Minnesota, Department of Neuroscience, Minneapolis, Minnesota
| | - Julia Klein
- University of Minnesota, Department of Neuroscience, Minneapolis, Minnesota
| | - Clarke Sauve
- University of Minnesota, Department of Neuroscience, Minneapolis, Minnesota
| | - Isaac Hoff
- University of Minnesota, Department of Neuroscience, Minneapolis, Minnesota
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33
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Louis ED, Faust PL. Essential tremor: the most common form of cerebellar degeneration? CEREBELLUM & ATAXIAS 2020; 7:12. [PMID: 32922824 PMCID: PMC7427947 DOI: 10.1186/s40673-020-00121-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
Background The degenerative cerebellar ataxias comprise a large and heterogeneous group of neurological diseases whose hallmark clinical feature is ataxia, and which are accompanied, to variable degrees, by other features that are attributable to cerebellar dysfunction. Essential tremor (ET) is an exceptionally common neurological disease whose primary motor feature is action tremor, although patients often manifest intention tremor, mild gait ataxia and several other features of cerebellar dysfunction. Main Body In this paper, we review the abundant evidence derived from clinical, neuroimaging and postmortem studies, linking ET to cerebellar dysfunction. Furthermore, we review the combination of clinical, natural history and postmortem features suggesting that ET is neurodegenerative. We then compare the prevalence of ET (400 – 900 cases per 100,000) to that of the other cerebellar degenerations (ranging from <0.5 – 9 cases per 100,000, and in composite likely to be on the order of 20 cases per 100,000) and conclude that ET is 20 to 45 times more prevalent than all other forms of cerebellar degeneration combined. Conclusion Given the data we present, it is logical to conclude that ET is, by far, the most common form of cerebellar degeneration.
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Affiliation(s)
- Elan D Louis
- Department of Neurology and Therapeutics, University of Texas Southwestern, Dallas, TX USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY USA
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34
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Zhu H, Meissner LE, Byrnes C, Tuymetova G, Tifft CJ, Proia RL. The Complement Regulator Susd4 Influences Nervous-System Function and Neuronal Morphology in Mice. iScience 2020; 23:100957. [PMID: 32179479 PMCID: PMC7075988 DOI: 10.1016/j.isci.2020.100957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 10/31/2019] [Accepted: 02/25/2020] [Indexed: 01/02/2023] Open
Abstract
The SUSD4 (Sushi domain-containing protein 4) gene encodes a complement inhibitor that is frequently deleted in 1q41q42 microdeletion syndrome, a multisystem congenital disorder that includes neurodevelopmental abnormalities. To understand SUSD4's role in the mammalian nervous system, we analyzed Susd4 knockout (KO) mice. Susd4 KO mice exhibited significant defects in motor performance and significantly higher levels of anxiety-like behaviors. Susd4 KO brain had abnormal “hairy” basket cells surrounding Purkinje neurons within the cerebellum and significantly reduced dendritic spine density in hippocampal pyramidal neurons. Neurons and oligodendrocyte lineage cells of wild-type mice were found to express Susd4 mRNA. Protein expression of the complement component C1q was increased in the brains of Susd4 KO mice. Our data indicate that SUSD4 plays an important role in neuronal functions, possibly via the complement pathway, and that SUSD4 deletion may contribute to the nervous system abnormalities in patients with 1q41q42 deletions. Susd4 is expressed in neurons and oligodendrocyte lineage cells Susd4 knockout mice have abnormal hippocampal and cerebellar neuronal morphologies Susd4 knockout mice exhibit anxiety-like behaviors and impaired motor function Susd4 knockout mice have elevated brain levels of the complement component C1q
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Affiliation(s)
- Hongling Zhu
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Laura E Meissner
- Office of the Clinical Director and Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Colleen Byrnes
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Galina Tuymetova
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Cynthia J Tifft
- Office of the Clinical Director and Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Richard L Proia
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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35
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Brown AM, White JJ, van der Heijden ME, Zhou J, Lin T, Sillitoe RV. Purkinje cell misfiring generates high-amplitude action tremors that are corrected by cerebellar deep brain stimulation. eLife 2020; 9:e51928. [PMID: 32180549 PMCID: PMC7077982 DOI: 10.7554/elife.51928] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
Tremor is currently ranked as the most common movement disorder. The brain regions and neural signals that initiate the debilitating shakiness of different body parts remain unclear. Here, we found that genetically silencing cerebellar Purkinje cell output blocked tremor in mice that were given the tremorgenic drug harmaline. We show in awake behaving mice that the onset of tremor is coincident with rhythmic Purkinje cell firing, which alters the activity of their target cerebellar nuclei cells. We mimic the tremorgenic action of the drug with optogenetics and present evidence that highly patterned Purkinje cell activity drives a powerful tremor in otherwise normal mice. Modulating the altered activity with deep brain stimulation directed to the Purkinje cell output in the cerebellar nuclei reduced tremor in freely moving mice. Together, the data implicate Purkinje cell connectivity as a neural substrate for tremor and a gateway for signals that mediate the disease.
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Affiliation(s)
- Amanda M Brown
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Joshua J White
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Meike E van der Heijden
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Joy Zhou
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
- Development, Disease Models & Therapeutics Graduate Program, Baylor College of MedicineHoustonUnited States
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36
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Abstract
Established medications that improve tremor include beta-adrenergic antagonists, primidone, topiramate, and ethanol. Less consistent efficacy is reported with many other medications, usually antiepileptic drugs. A number of investigational medications, including T-type calcium channel blockers and allosteric gamma-aminobutyric acid-A modulators, are being developed for tremor. Deep brain stimulation techniques continues to be refined and focused ultrasound thalamotomy now offers an incisionless surgical option. Finally a number of peripheral electrical and mechanical devices are under development for tremor.
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Affiliation(s)
- William George Ondo
- Movement Disorders-Methodist Neurological Institute, Weill Cornel Medical School, 6560 Fannin Suite 1002, Houston, TX 77025, USA.
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37
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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: 98] [Impact Index Per Article: 24.5] [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.
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38
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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.
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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
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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.
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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.
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40
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Contextualizing the pathology in the essential tremor cerebellar cortex: a patholog-omics approach. Acta Neuropathol 2019; 138:859-876. [PMID: 31317229 DOI: 10.1007/s00401-019-02043-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022]
Abstract
Several morphological changes, centered in/around Purkinje cells (PCs), have been identified in the cerebellum of essential tremor (ET) patients. These changes have not been contextualized within a broader degenerative disease spectrum, limiting their interpretability. To address this, we compared the severity and patterning of degenerative changes within the cerebellar cortex in patients with ET, other neurodegenerative disorders of the cerebellum (spinocerebellar ataxias (SCAs), multiple system atrophy (MSA)], and other disorders that may involve the cerebellum [Parkinson's disease (PD), dystonia]. Using a postmortem series of 156 brains [50 ET, 23 SCA (6 SCA3; 17 SCA 1, 2 or 6), 15 MSA, 29 PD, 14 dystonia, 25 controls], we generated data on 37 quantitative morphologic metrics, which were grouped into 8 broad categories: (1) PC loss, (2) heterotopic PCs, (3) PC dendritic changes, (4) PC axonal changes (torpedoes), (5) PC axonal changes (other than torpedoes), (6) PC axonal changes (torpedo-associated), (7) basket cell axonal hypertrophy, (8) climbing fiber-PC synaptic changes. Our analyses used z scored raw data for each metric across all diagnoses (5772 total data items). Principal component analysis revealed that diagnostic groups were not uniform with respect to cerebellar pathology. Dystonia and PD each differed from controls in only 2/37 metrics, whereas ET differed in 21, SCA3 in 8, MSA in 19, and SCA1/2/6 in 26 metrics. Comparing ET with primary disorders of cerebellar degeneration (i.e., SCAs), we observed a spectrum of changes reflecting differences of degree, being generally mild in ET and SCA3 and more severe in SCA1/2/6. Comparative analyses across morphologic categories demonstrated differences in relative expression, defining distinctive patterns of changes in these groups. Thus, the degree of cerebellar degeneration in ET aligns it with a milder end in the spectrum of cerebellar degenerative disorders, and a somewhat distinctive signature of degenerative changes marks each of these disorders.
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Dahmardeh N, Shabani M, Basiri M, Kalantaripour TP, Asadi-Shekaari M. Functional Antagonism of Sphingosine-1-Phosphate Receptor 1 Prevents Harmaline-Induced Ultrastructural Alterations and Caspase-3 Mediated Apoptosis. Malays J Med Sci 2019; 26:28-38. [PMID: 31496891 PMCID: PMC6719891 DOI: 10.21315/mjms2019.26.4.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 07/22/2019] [Indexed: 12/21/2022] Open
Abstract
Background There is a meaningful necessity for a targeted therapy of essential tremor (ET), as medications have not been developed specifically for ET. For nearly a century, many drugs have been applied in the treatment of tremor but the drug treatment of ET remains still unknown. Some potential therapeutic factors such fingolimod (FTY720) can be effectively used to treat ET in animals. In the present research, the effect of FTY720, the immunomodulatory sphingosine 1-phosphate (S1P) analog, on degeneration of cerebellar and olivary neurons induced by harmaline in male rats was investigated. Methods The animals were allotted into control dimethyl sulfoxide (DMSO), saline + harmaline [30 mg/kg, intraperitoneally, (i.p.)], harmaline + FTY720 (1 mg/kg, i.p, 1 h and 24 h before harmaline injection) groups (n = 10). The cerebellum and inferior olive nucleus (ION) were studied for neuronal degeneration using immunohistochemistry (IHC) and ultrastructural study by transmission electron microscopy (TEM) techniques. Results Harmaline caused neuronal cell loss, caspase-3 mediated apoptosis, astrocytosis and ultrastructural changes in cerebellar Purkinje cells and inferior olive neurons. FTY720 exhibited neuroprotective effects on cerebellar Purkinje cells and inferior olivary neurons. Conclusion These results suggest that FTY720 has potential efficacy for prevention of ET neurodegeneration and astrocytosis induced by harmaline in male rats.
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Affiliation(s)
- Narjes Dahmardeh
- Department of Anatomical Sciences, Afzalipour Medical Faculty, Kerman University of Medical Sciences, Kerman, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Zabol University of Medical Sciences, Zabol, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohsen Basiri
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Taj Pari Kalantaripour
- Department of Physiology, School of Medicine, Kerman Branch, Islamic Azad University, Kerman, Iran
| | - Majid Asadi-Shekaari
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
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42
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Mavroudis I, Petridis F, Kazis D. Neuroimaging and neuropathological findings in essential tremor. Acta Neurol Scand 2019; 139:491-496. [PMID: 30977113 DOI: 10.1111/ane.13101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/14/2019] [Accepted: 04/05/2019] [Indexed: 12/21/2022]
Abstract
Essential tremor is a chronic neurological syndrome of heterogenous clinical phenotypes and multiple etiologies. Numerous studies have been done in order to investigate the pathological, neuroimaging, physiological, and clinical features of essential tremor; however, a clear pathophysiological mechanism has not been identified. One of the brain structures has been extensively investigated at the macroscopic and the microscopic level in the cerebellum. In the present study, we aim to discuss the main neuroimaging and neuropathological changes of the cerebellum in essential tremor.
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Affiliation(s)
- Ioannis Mavroudis
- Department of Neurology Leeds Teaching Hospitals Leeds UK
- Third Department of Neurology Aristotle University of Thessaloniki Thessaloniki Greece
| | - Foivos Petridis
- Third Department of Neurology Aristotle University of Thessaloniki Thessaloniki Greece
| | - Dimitrios Kazis
- Third Department of Neurology Aristotle University of Thessaloniki Thessaloniki Greece
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Mari L, Matiasek K, Jenkins CA, De Stefani A, Ricketts SL, Forman O, De Risio L. Hereditary ataxia in four related Norwegian Buhunds. J Am Vet Med Assoc 2019; 253:774-780. [PMID: 30179085 DOI: 10.2460/javma.253.6.774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CASE DESCRIPTION Two 12-week-old Norwegian Buhunds from a litter of 5 were evaluated because of slowly progressive cerebellar ataxia and fine head tremors. Two other females from the same pedigree had been previously evaluated for similar signs. CLINICAL FINDINGS Findings of general physical examination, CBC, and serum biochemical analysis were unremarkable for all affected puppies. Brain MRI and CSF analysis, including PCR assays for detection of Toxoplasma gondii, Neospora caninum, and canine distemper virus, were performed for 3 dogs, yielding unremarkable results. Urinary organic acid screening, enzyme analysis of fibroblasts cultured from skin biopsy specimens, and brainstem auditory-evoked response testing were performed for 2 puppies, and results were also unremarkable. TREATMENT AND OUTCOME The affected puppies were euthanized at the breeder's request, and their brains and spinal cords were submitted for histologic examination. Histopathologic findings included a markedly reduced expression of calbindin D28K and inositol triphosphate receptor 1 by Purkinje cells, with only mild signs of neuronal degeneration. Results of pedigree analysis suggested an autosomal recessive mode of inheritance. Candidate-gene analysis via mRNA sequencing for 2 of the affected puppies revealed no genetic variants that could be causally associated with the observed abnormalities. CLINICAL RELEVANCE Findings for the dogs of this report suggested the existence of a hereditary form of ataxia in Norwegian Buhunds with histologic characteristics suggestive of Purkinje cell dysfunction. The presence of hereditary ataxia in this breed must be considered both in clinical settings and for breeding strategies.
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Heterotopic Purkinje Cells: a Comparative Postmortem Study of Essential Tremor and Spinocerebellar Ataxias 1, 2, 3, and 6. THE CEREBELLUM 2019; 17:104-110. [PMID: 28791574 DOI: 10.1007/s12311-017-0876-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Essential tremor (ET) is among the most common neurological diseases. Postmortem studies have noted a series of pathological changes in the ET cerebellum. Heterotopic Purkinje cells (PCs) are those whose cell body is mis-localized in the molecular layer. In neurodegenerative settings, these are viewed as a marker of the progression of neuronal degeneration. We (1) quantify heterotopias in ET cases vs. controls, (2) compare ET cases to other cerebellar degenerative conditions (spinocerebellar ataxias (SCAs) 1, 2, 3, and 6), (3) compare these SCAs to one another, and (4) assess heterotopia within the context of associated PC loss in each disease. Heterotopic PCs were quantified using a standard LH&E-stained section of the neocerebellum. Counts were normalized to PC layer length (n-heterotopia count). It is also valuable to consider PC counts when assessing heterotopia, as loss of PCs extends both to normally located as well as heterotopic PCs. Therefore, we divided n-heterotopias by PC counts. There were 96 brains (43 ET, 31 SCA [12 SCA1, 7 SCA2, 7 SCA3, 5 SCA6], and 22 controls). The median number of n-heterotopias in ET cases was two times higher than that of the controls (2.6 vs. 1.2, p < 0.05). The median number of n-heterotopias in the various SCAs formed a spectrum, with counts being highest in SCA3 and SCA1. In analyses that factored in PC counts, ET had a median n-heterotopia/Purkinje cell count that was three times higher than the controls (0.35 vs. 0.13, p < 0.01), and SCA1 and SCA2 had counts that were 5.5 and 11 times higher than the controls (respective p < 0.001). The median n-heterotopia/PC count in ET was between that of the controls and the SCAs. Similarly, the median PC count in ET was between that of the controls and the SCAs; the one exception was SCA3, in which the PC population is well known to be preserved. Heterotopia is a disease-associated feature of ET. In comparison, several of the SCAs evidenced even more marked heterotopia, although a spectrum existed across the SCAs. The median n-heterotopia/PC count and median PC in ET was between that of the controls and the SCAs; hence, in this regard, ET could represent an intermediate state or a less advanced state of spinocerebellar atrophy.
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Lee PJ, Kerridge CA, Chatterjee D, Koeppen AH, Faust PL, Louis ED. A Quantitative Study of Empty Baskets in Essential Tremor and Other Motor Neurodegenerative Diseases. J Neuropathol Exp Neurol 2019; 78:113-122. [PMID: 30590599 PMCID: PMC6330169 DOI: 10.1093/jnen/nly114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The underlying biology of essential tremor (ET) is poorly understood. Purkinje cell (PC) loss has been observed in some studies, although this finding remains somewhat controversial. Basket cells are interneurons whose axonal collaterals form a plexus around PC soma. When there is PC loss, this basket plexus appears empty. We used dual immunohistochemical staining for calbindin D28k and glutamic acid decarboxylase to quantify "empty baskets" as an indirect and alternative method of detecting PC loss. Microscopic analyses on 127 brains included ET and a spectrum of motor neurodegenerative diseases (50 ET, 27 spinocerebellar ataxias [SCAs], 25 Parkinson disease, 25 controls). The median percentage of empty baskets in ET patients was 1.5 times higher than controls (48.8% vs 33.5%, p < 0.001) but lower in ET than in SCA1 (59.7%, p = 0.011), SCA2 (77.5%, p = 0.003), and SCA6 (87.0%, p < 0.001). PC loss is not a feature of SCA3, and the median percentage of empty baskets (30.1%) was similar to controls (p = 0.303). These data provide support for PC loss in ET and are consistent with the notion that ET could represent a mild form of cerebellar degeneration with an intermediate degree of PC loss.
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Affiliation(s)
- Paul J Lee
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, Connecticut; New York, New York; Albany, New York
| | - Chloë A Kerridge
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York
| | - Debotri Chatterjee
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York
| | - Arnulf H Koeppen
- Research, Neurology, and Pathology Services, Veterans Affairs Medical Center and Departments of Neurology and Pathology, Albany Medical College, Albany
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York
| | - Elan D Louis
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, Connecticut; New York, New York; Albany, New York
- Department of Neurology, Yale School of Medicine, Yale University, New Haven
- Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, Connecticut
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Absence of Mutation Enrichment for Genes Phylogenetically Conserved in the Olivocerebellar Motor Circuitry in a Cohort of Canadian Essential Tremor Cases. Mol Neurobiol 2018; 56:4317-4321. [PMID: 30315477 DOI: 10.1007/s12035-018-1369-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/27/2018] [Indexed: 10/28/2022]
Abstract
Essential Tremor is a prevalent neurological disorder of unknown etiology. Studies suggest that genetic factors contribute to this pathology. To date, no causative mutations in a gene have been reproducibly reported. All three structures of the olivocerebellar motor circuitry have been linked to Essential Tremor. We postulated that genes enriched for their expression in the olivocerebellar circuitry would be more susceptible to harbor mutations in Essential Tremor patients. A list of 11 candidate genes, enriched for their expression in the olivocerebellar circuitry, was assessed for their variation spectrum and frequency in a cohort of Canadian Essential Tremor cases. Our results from this list of 11 candidate genes do not support an association for Essential Tremor in our cohort of Canadian cases. The heterogenic nature of ET and modest size of the cohort used in this study are two confounding factors that could explain these results.
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47
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Edamakanti CR, Do J, Didonna A, Martina M, Opal P. Mutant ataxin1 disrupts cerebellar development in spinocerebellar ataxia type 1. J Clin Invest 2018. [PMID: 29533923 DOI: 10.1172/jci96765] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Spinocerebellar ataxia type 1 (SCA1) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the protein ATXN1, which is involved in transcriptional regulation. Although symptoms appear relatively late in life, primarily from cerebellar dysfunction, pathogenesis begins early, with transcriptional changes detectable as early as a week after birth in SCA1-knockin mice. Given the importance of this postnatal period for cerebellar development, we asked whether this region might be developmentally altered by mutant ATXN1. We found that expanded ATXN1 stimulates the proliferation of postnatal cerebellar stem cells in SCA1 mice. These hyperproliferating stem cells tended to differentiate into GABAergic inhibitory interneurons rather than astrocytes; this significantly increased the GABAergic inhibitory interneuron synaptic connections, disrupting cerebellar Purkinje cell function in a non-cell autonomous manner. We confirmed the increased basket cell-Purkinje cell connectivity in human SCA1 patients. Mutant ATXN1 thus alters the neural circuitry of the developing cerebellum, setting the stage for the later vulnerability of Purkinje cells to SCA1. We propose that other late-onset degenerative diseases may also be rooted in subtle developmental derailments.
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Affiliation(s)
| | - Jeehaeh Do
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Puneet Opal
- Davee Department of Neurology, and.,Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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48
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Louis ED, Kuo SH, Wang J, Tate WJ, Pan MK, Kelly GC, Gutierrez J, Cortes EP, Vonsattel JPG, Faust PL. Cerebellar Pathology in Familial vs. Sporadic Essential Tremor. THE CEREBELLUM 2018; 16:786-791. [PMID: 28364185 DOI: 10.1007/s12311-017-0853-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Familial and sporadic essential tremor (ET) cases differ in several respects. Whether they differ with respect to cerebellar pathologic changes has yet to be studied. We quantified a broad range of postmortem features (Purkinje cell (PC) counts, PC axonal torpedoes, a host of associated axonal changes, heterotopic PCs, and hairy basket ratings) in 60 ET cases and 30 controls. Familial ET was defined using both liberal criteria (n = 27) and conservative criteria (n = 20). When compared with controls, ET cases had lower PC counts, more torpedoes, more heterotopic PCs, a higher hairy basket rating, an increase in PC axonal collaterals, an increase in PC thickened axonal profiles, and an increase in PC axonal branching. Familial and sporadic ET had similar postmortem changes, with few exceptions, regardless of the definition criteria. The PC counts were marginally lower in familial than sporadic ET (respective p values = 0.059 [using liberal criteria] and 0.047 [using conservative criteria]). The PC thickened axonal profile count was marginally lower in familial ET than sporadic ET (respective p values = 0.037 [using liberal criteria] and 0.17 [using conservative criteria]), and the PC axonal branching count was marginally lower in familial than sporadic ET (respective p values = 0.045 [using liberal criteria] and 0.079 [using conservative criteria]). After correction for multiple comparisons, however, there were no significant differences. Overall, familial and sporadic ET cases share very similar cerebellar postmortem features. These data indicate that pathological changes in the cerebellum are a part of the pathophysiological cascade of events in both forms of ET.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, PO Box 208018, New Haven, CT, 06520-8018, 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.
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jie Wang
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Department of Basic and Community Nursing, School of Nursing, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - William J Tate
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Ming-Kai Pan
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Department of Medical Research, National Taiwan University, Taipei, Taiwan
| | - Geoffrey C Kelly
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Jesus Gutierrez
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, PO Box 208018, New Haven, CT, 06520-8018, USA
| | - Etty P Cortes
- 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, Columbia University, New York, NY, USA
| | - Jean-Paul G Vonsattel
- 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, 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
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Louis ED, Diaz DT, Kuo SH, Gan SR, Cortes EP, Vonsattel JPG, Faust PL. Inferior Olivary nucleus degeneration does not lessen tremor in essential tremor. CEREBELLUM & ATAXIAS 2018; 5:1. [PMID: 29372062 PMCID: PMC5769208 DOI: 10.1186/s40673-018-0080-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/03/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND In traditional models of essential tremor, the inferior olivary nucleus was posited to play a central role as the pacemaker for the tremor. However, recent data call this disease model into question. CASE PRESENTATION Our patient had progressive, long-standing, familial essential tremor. Upper limb tremor began at age 10 and worsened over time. It continued to worsen during the nine-year period he was enrolled in our brain donation program (age 85 - 94 years), during which time the tremor moved from the moderate to severe range on examination. On postmortem examination at age 94, there were degenerative changes in the cerebellar cortex, as have been described in the essential tremor literature. Additionally, there was marked degeneration of the inferior olivary nucleus, which was presumed to be of more recent onset. Such degeneration has not been previously described in essential tremor postmortems. Despite the presence of this degeneration, the patient's tremor not only persisted but it continued to worsen during the final decade of his life. CONCLUSIONS Although the pathophysiology of essential tremor is not completely understood, evidence such as this suggests that the inferior olivary nucleus does not play a critical role in the generation of tremor in these patients.
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Affiliation(s)
- Elan D. Louis
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, PO Box 208018, New Haven, CT 06520-8018 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
| | - Daniel Trujillo Diaz
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, PO Box 208018, New Haven, CT 06520-8018 USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY USA
| | - Shi-Rui Gan
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY USA
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Etty P. Cortes
- 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, Columbia University, New York, NY USA
| | - Jean Paul G. Vonsattel
- 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, 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
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Abstract
Essential tremor (ET) is a progressive and highly prevalent neurologic disease. Along with the tremors, mild to moderate gait ataxia and other signs of cerebellar dysfunction may occur (i.e., subtle saccadic eye movement abnormalities and abnormalities of motor timing) as well as cognitive features, some of which may be due to cerebellar dysfunction. Numerous neuroimaging studies indicate the presence of functional, metabolic, and structural abnormalities in the cerebellum of a patient with ET. In tandem with these clinical and imaging studies, which were gathering increasing support for the notion that the cerebellum and/or cerebellar systems seemed to be at the root of ET, a growing postmortem literature is for the first time beginning to identify microscopic abnormalities in the ET brain, most of which are centered on the Purkinje cells and connected neuronal populations, and are likely to be degenerative. In terms of treatment, most of these pharmacotherapeutic agents serve to enhance GABAergic neurotransmission, further bolstering the notion that ET may very well be a disorder with a primary Purkinje cell dysfunction resulting in reduced cerebellar cortical inhibition. Similarly, the interruption of presumably abnormal cerebellar outflow pathways to the thalamus is the mechanism of deep-brain stimulation surgery, which is highly effective in treating ET.
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Affiliation(s)
- Elan D Louis
- Department of Neurology and Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, United States; Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, United States.
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