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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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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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Li T, Le W, Jankovic J. Linking the cerebellum to Parkinson disease: an update. Nat Rev Neurol 2023; 19:645-654. [PMID: 37752351 DOI: 10.1038/s41582-023-00874-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2023] [Indexed: 09/28/2023]
Abstract
Parkinson disease (PD) is characterized by heterogeneous motor and non-motor symptoms, resulting from neurodegeneration involving various parts of the central nervous system. Although PD pathology predominantly involves the nigral-striatal system, growing evidence suggests that pathological changes extend beyond the basal ganglia into other parts of the brain, including the cerebellum. In addition to a primary involvement in motor control, the cerebellum is now known to also have an important role in cognitive, sleep and affective processes. Over the past decade, an accumulating body of research has provided clinical, pathological, neurophysiological, structural and functional neuroimaging findings that clearly establish a link between the cerebellum and PD. This Review presents an overview and update on the involvement of the cerebellum in the clinical features and pathogenesis of PD, which could provide a novel framework for a better understanding the heterogeneity of the disease.
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Affiliation(s)
- Tianbai Li
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Weidong Le
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, the First Affiliated Hospital, Dalian Medical University, Dalian, China.
- Institute of Neurology, Sichuan Academy of Medical Sciences, Sichuan Provincial Hospital, Chengdu, China.
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
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Kumar A, Lin CC, Kuo SH, Pan MK. Physiological Recordings of the Cerebellum in Movement Disorders. CEREBELLUM (LONDON, ENGLAND) 2023; 22:985-1001. [PMID: 36070135 PMCID: PMC10354710 DOI: 10.1007/s12311-022-01473-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/27/2022] [Indexed: 06/15/2023]
Abstract
The cerebellum plays an important role in movement disorders, specifically in symptoms of ataxia, tremor, and dystonia. Understanding the physiological signals of the cerebellum contributes to insights into the pathophysiology of these movement disorders and holds promise in advancing therapeutic development. Non-invasive techniques such as electroencephalogram and magnetoencephalogram can record neural signals with high temporal resolution at the millisecond level, which is uniquely suitable to interrogate cerebellar physiology. These techniques have recently been implemented to study cerebellar physiology in healthy subjects as well as individuals with movement disorders. In the present review, we focus on the current understanding of cerebellar physiology using these techniques to study movement disorders.
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Affiliation(s)
- Ami Kumar
- Department of Neurology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 650 W 168thStreet, Room 305, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University Irving Medical Center, New York, NY, USA
| | - Chih-Chun Lin
- Department of Neurology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 650 W 168thStreet, Room 305, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University Irving Medical Center, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 650 W 168thStreet, Room 305, New York, NY, 10032, USA.
- Initiative for Columbia Ataxia and Tremor, Columbia University Irving Medical Center, New York, NY, USA.
| | - Ming-Kai Pan
- Cerebellar Research Center, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin, 64041, Taiwan.
- Department and Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, 10051, Taiwan.
- Department of Medical Research, National Taiwan University Hospital, Taipei, 10002, Taiwan.
- Institute of Biomedical Sciences, Academia Sinica, Taipei City, 11529, Taiwan.
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Rasmussen CLM, Thomsen LB, Heegaard CW, Moos T, Burkhart A. The Npc2 Gt(LST105)BygNya mouse signifies pathological changes comparable to human Niemann-Pick type C2 disease. Mol Cell Neurosci 2023; 126:103880. [PMID: 37454976 DOI: 10.1016/j.mcn.2023.103880] [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: 03/17/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023] Open
Abstract
INTRODUCTION Niemann-Pick type C2 disease (NP-C2) is a fatal neurovisceral disorder caused by defects in the lysosomal cholesterol transporter protein NPC2. Consequently, cholesterol and other lipids accumulate within the lysosomes, causing a heterogeneous spectrum of clinical manifestations. Murine models are essential for increasing the understanding of the complex pathology of NP-C2. This study, therefore, aims to describe the neurovisceral pathology in the NPC2-deficient mouse model to evaluate its correlation to human NP-C2. METHODS Npc2-/- mice holding the LST105 mutation were used in the present study (Npc2Gt(LST105)BygNya). Body and organ weight and histopathological evaluations were carried out in six and 12-week-old Npc2-/- mice, with a special emphasis on neuropathology. The Purkinje cell (PC) marker calbindin, the astrocytic marker GFAP, and the microglia marker IBA1 were included to assess PC degeneration and neuroinflammation, respectively. In addition, the pathology of the liver, lungs, and spleen was assessed using hematoxylin and eosin staining. RESULTS Six weeks old pre-symptomatic Npc2-/- mice showed splenomegaly and obvious neuropathological changes, especially in the cerebellum, where initial PC loss and neuroinflammation were evident. The Npc2-/- mice developed neurological symptoms at eight weeks of age, severely progressing until the end-stage of the disease at 12 weeks. At the end-stage of the disease, Npc2-/- mice were characterized by growth retardation, tremor, cerebellar ataxia, splenomegaly, foam cell accumulation in the lungs, liver, and spleen, brain atrophy, pronounced PC degeneration, and severe neuroinflammation. CONCLUSION The Npc2Gt(LST105)BygNya mouse model resembles the pathology seen in NP-C2 patients and denotes a valuable model for increasing the understanding of the complex disease manifestation and is relevant for testing the efficacies of new treatment strategies.
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Affiliation(s)
| | - Louiza Bohn Thomsen
- Neurobiology Research and Drug Delivery, Department of Health Science and Technology, Aalborg University, Denmark
| | | | - Torben Moos
- Neurobiology Research and Drug Delivery, Department of Health Science and Technology, Aalborg University, Denmark
| | - Annette Burkhart
- Neurobiology Research and Drug Delivery, Department of Health Science and Technology, Aalborg University, Denmark.
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Spampinato DA, Casula EP, Koch G. The Cerebellum and the Motor Cortex: Multiple Networks Controlling Multiple Aspects of Behavior. Neuroscientist 2023:10738584231189435. [PMID: 37649430 DOI: 10.1177/10738584231189435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The cerebellum and its thalamic projections to the primary motor cortex (M1) are well known to play an essential role in executing daily actions. Anatomic investigations in animals and postmortem humans have established the reciprocal connections between these regions; however, how these pathways can shape cortical activity in behavioral contexts and help promote recovery in neuropathological conditions remains not well understood. The present review aims to provide a comprehensive description of these pathways in animals and humans and discuss how novel noninvasive brain stimulation (NIBS) methods can be used to gain a deeper understanding of the cerebellar-M1 connections. In the first section, we focus on recent animal literature that details how information sent from the cerebellum and thalamus is integrated into an broad network of cortical motor neurons. We then discuss how NIBS approaches in humans can be used to reliably assess the connectivity between the cerebellum and M1. Moreover, we provide the latest perspectives on using advanced NIBS approaches to investigate and modulate multiple cerebellar-cortical networks involved in movement behavior and plasticity. Finally, we discuss how these emerging methods have been used in translation research to produce long-lasting modifications of cerebellar-thalamic-M1 to restore cortical activity and motor function in neurologic patients.
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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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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: 9] [Impact Index Per Article: 9.0] [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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9
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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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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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Ishibashi T, Baba H. Paranodal Axoglial Junctions, an Essential Component in Axonal Homeostasis. Front Cell Dev Biol 2022; 10:951809. [PMID: 35874818 PMCID: PMC9299063 DOI: 10.3389/fcell.2022.951809] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/20/2022] [Indexed: 11/28/2022] Open
Abstract
In vertebrates, a high density of voltage-gated Na+ channel at nodes of Ranvier and of voltage-gated K+ channel at juxtaparanodes is necessary for rapid propagation of action potential, that is, for saltatory conduction in myelinated axons. Myelin loops attach to the axonal membrane and form paranodal axoglial junctions (PNJs) at paranodes adjacent to nodes of Ranvier. There is growing evidence that the PNJs contribute to axonal homeostasis in addition to their roles as lateral fences that restrict the location of nodal axolemmal proteins for effective saltatory conduction. Perturbations of PNJs, as in specific PNJ protein knockouts as well as in myelin lipid deficient mice, result in internodal axonal alterations, even if their internodal myelin is preserved. Here we review studies showing that PNJs play crucial roles in the myelinated axonal homeostasis. The present evidence points to two functions in particular: 1) PNJs facilitate axonal transport of membranous organelles as well as cytoskeletal proteins; and 2) they regulate the axonal distribution of type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) in cerebellar Purkinje axons. Myelinated axonal homeostasis depends among others on the state of PNJs, and consequently, a better understanding of this dependency may contribute to the clarification of CNS disease mechanisms and the development of novel therapies.
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Affiliation(s)
- Tomoko Ishibashi
- Department of Functional Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Hiroko Baba
- Department of Occupational Therapy, Faculty of Rehabilitation, Niigata University of Health and Welfare, Niigata, Japan
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12
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A review on pathology, mechanism, and therapy for cerebellum and tremor in Parkinson's disease. NPJ Parkinsons Dis 2022; 8:82. [PMID: 35750692 PMCID: PMC9232614 DOI: 10.1038/s41531-022-00347-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/30/2022] [Indexed: 12/16/2022] Open
Abstract
Tremor is one of the core symptoms of Parkinson’s disease (PD), but its mechanism is poorly understood. The cerebellum is a growing focus in PD-related researches and is reported to play an important role in tremor in PD. The cerebellum may participate in the modulation of tremor amplitude via cerebello-thalamo-cortical circuits. The cerebellar excitatory projections to the ventral intermediate nucleus of the thalamus may be enhanced due to PD-related changes, including dopaminergic/non-dopaminergic system abnormality, white matter damage, and deep nuclei impairment, which may contribute to dysregulation and resistance to levodopa of tremor. This review summarized the pathological, structural, and functional changes of the cerebellum in PD and discussed the role of the cerebellum in PD-related tremor, aiming to provide an overview of the cerebellum-related mechanism of tremor in PD.
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13
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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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14
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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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15
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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: 19] [Impact Index Per Article: 6.3] [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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16
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Purkinje cell axonal swellings enhance action potential fidelity and cerebellar function. Nat Commun 2021; 12:4129. [PMID: 34226561 PMCID: PMC8257784 DOI: 10.1038/s41467-021-24390-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/11/2021] [Indexed: 11/08/2022] Open
Abstract
Axonal plasticity allows neurons to control their output, which critically determines the flow of information in the brain. Axon diameter can be regulated by activity, yet how morphological changes in an axon impact its function remains poorly understood. Axonal swellings have been found on Purkinje cell axons in the cerebellum both in healthy development and in neurodegenerative diseases, and computational models predicts that axonal swellings impair axonal function. Here we report that in young Purkinje cells, axons with swellings propagated action potentials with higher fidelity than those without, and that axonal swellings form when axonal failures are high. Furthermore, we observed that healthy young adult mice with more axonal swellings learn better on cerebellar-related tasks than mice with fewer swellings. Our findings suggest that axonal swellings underlie a form of axonal plasticity that optimizes the fidelity of action potential propagation in axons, resulting in enhanced learning.
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17
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Shalash AS, Hamid E, Elrassas H, Bahbah EI, Mansour AH, Mohamed H, Elbalkimy M. Non-motor symptoms in essential tremor, akinetic rigid and tremor-dominant subtypes of Parkinson's disease. PLoS One 2021; 16:e0245918. [PMID: 33503062 PMCID: PMC7840014 DOI: 10.1371/journal.pone.0245918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 01/10/2021] [Indexed: 12/30/2022] Open
Abstract
Objectives To compare non-motor symptoms (NMSs) among patients with essential tremor (ET), Parkinson’s disease (PD) subtypes (akinetic-rigid type (ART) and tremor-dominant type (TDT)), and healthy controls. Patients and methods This retrospective study included 129 participants, 72 PD (33 PD-ART, 33 PD-TDT, and 6 Mixed), 29 ET patients, and 28 controls. PD patients were assessed by the unified Parkinson’s disease rating scale (UPDRS), Hoehn, and Yahr scale (H&Y), while ET patients were evaluated by the Fahn Tolosa Marin Tremor Rating Scale. All subjects were evaluated by non-motor symptoms scale (NMSS) for NMSs and Beck depression inventory (BDI) for depression. Results PD subtypes groups, ET, and controls were age and gender-matched. Compared to controls, all PD, PD subtypes, and ET showed significantly worse most of NMSs (p<0.001) and depression. Compared to ET, all PD and PD-ART had significantly worse gastrointestinal (p = 0.002), urinary symptoms (p = 0.001, p = 0.003) and depression (p = 0.002) and PD-TDT worse depression, while ET patients showed worse memory/attention than PD subtypes. Total NMSS of ET is highly correlated to depression and moderately to tremor severity and age of onset, while total of NMSS is highly correlated to depression, disease severity, and disability. Conclusion The current study demonstrated several comparable domains of NMSs of PD subtypes and ET, except worse gastrointestinal and urinary symptoms among PD-ART. Identifying different NMSs profiles is important for predicting, better assessing, and tailoring management of ET and PD subtypes.
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Affiliation(s)
- Ali S Shalash
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Eman Hamid
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Hanan Elrassas
- Okasha Institute of Psychiatry, Ain Shams University, Cairo, Egypt
| | - Eshak I Bahbah
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Alia H Mansour
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Hadeer Mohamed
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
| | - Mahmoud Elbalkimy
- Faculty of Medicine, Department of Neurology, Ain Shams University, Cairo, Egypt
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18
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Gossard TR, McCarter SJ, Gorres E, Feemster JC, Timm PC, Teigen LN, Ralston CL, Westerland SM, Conway JP, Jagielski JT, Olson CD, Edgar LJ, Veum EL, Savica R, Boeve BF, Silber MH, St Louis EK. Quantitative REM Sleep without Atonia in Parkinson's Disease and Essential Tremor. Mov Disord Clin Pract 2020; 8:37-43. [PMID: 33426157 DOI: 10.1002/mdc3.13112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 11/08/2022] Open
Abstract
Background Rapid eye movement (REM) sleep behavior disorder (RBD) occurs occasionally in essential tremor (ET), but polysomnographic REM sleep without atonia (RSWA) analyses have been sparse. Objective To characterize the amount and distribution of polysomnographic RSWA, the electrophysiologic substrate of RBD, in patients with Parkinson's disease (PD) and ET. Methods We analyzed quantitative RSWA in 73 patients: PD (23), ET (23), and age-sex-matched controls (27). None had dream-enactment behavior history or received antidepressants. Phasic, tonic, "any," and phasic-burst duration RSWA measures were calculated in the submentalis (SM) and anterior tibialis (AT) muscles. The automated REM atonia index (RAI) was also determined. Statistical analysis was performed by Kruskal-Wallis rank-sum and Mann-Whitney tests. Results SM phasic RSWA was significantly greater for PD than ET patients and controls (12.5% ± 12.8% vs. 4.9% ± 6.7%, 3.9% ± 2.6%), as was SM "any" (13.54% ± 14.30% vs. 5.2% ± 7.6%, 4.2% ± 2.6%). RAI was significantly lower in PD than in ET and controls (0.78 ± 0.23 vs. 0.92 ± 0.09 vs. 0.90 ± 0.17, P ≤ 0.005), but no different between ET and controls. AT phasic and "any" RSWA was similar between the 3 groups. ET and control RSWA was similar in all measures. Two ET patients (8.7%) had SM RSWA similar to PD patients. Conclusions Elevated SM RSWA distinguished PD from ET in patients without dream-enactment symptoms and occurs frequently in PD patients, and in isolated tremor suggests underlying synucleinopathy. Prospective studies will further validate these findings.
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Affiliation(s)
- Thomas R Gossard
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - Stuart J McCarter
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Department of Neurology Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Evan Gorres
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - John C Feemster
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - Paul C Timm
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - Luke N Teigen
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - Christy L Ralston
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Cornell College Mount Vernon Iowa USA
| | - Sarah M Westerland
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA
| | - Jimmy P Conway
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Luther College Decorah Iowa USA
| | - Jack T Jagielski
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Luther College Decorah Iowa USA
| | - Carl D Olson
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,St. Olaf College Northfield Minnesota USA
| | - Liam J Edgar
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,St. Olaf College Northfield Minnesota USA
| | - Emma L Veum
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Luther College Decorah Iowa USA
| | - Rodolfo Savica
- Department of Neurology Mayo Clinic College of Medicine and Science Rochester Minnesota USA.,Department of Health Science Research Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Brad F Boeve
- Department of Neurology Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Michael H Silber
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Department of Neurology Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Erik K St Louis
- Division of Pulmonary and Critical Care Medicine Mayo Center for Sleep Medicine Scottsdale Arizona USA.,Department of Neurology Mayo Clinic College of Medicine and Science Rochester Minnesota USA
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19
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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: 92] [Impact Index Per Article: 23.0] [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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20
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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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21
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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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22
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Maia PD, Raj A, Kutz JN. Slow-gamma frequencies are optimally guarded against effects of neurodegenerative diseases and traumatic brain injuries. J Comput Neurosci 2019; 47:1-16. [PMID: 31165337 DOI: 10.1007/s10827-019-00714-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 02/02/2019] [Accepted: 03/19/2019] [Indexed: 01/10/2023]
Abstract
We introduce a computational model for the cellular level effects of firing rate filtering due to the major forms of neuronal injury, including demyelination and axonal swellings. Based upon experimental and computational observations, we posit simple phenomenological input/output rules describing spike train distortions and demonstrate that slow-gamma frequencies in the 38-41 Hz range emerge as the most robust to injury. Our signal-processing model allows us to derive firing rate filters at the cellular level for impaired neural activity with minimal assumptions. Specifically, we model eight experimentally observed spike train transformations by discrete-time filters, including those associated with increasing refractoriness and intermittent blockage. Continuous counterparts for the filters are also obtained by approximating neuronal firing rates from spike trains convolved with causal and Gaussian kernels. The proposed signal processing framework, which is robust to model parameter calibration, is an abstraction of the major cellular-level pathologies associated with neurodegenerative diseases and traumatic brain injuries that affect spike train propagation and impair neuronal network functionality. Our filters are well aligned with the spectrum of dynamic memory fields including working memory, visual consciousness, and other higher cognitive functions that operate in a frequency band that is - at a single cell level - optimally guarded against common types of pathological effects. In contrast, higher-frequency neural encoding, such as is observed with short-term memory, are susceptible to neurodegeneration and injury.
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Affiliation(s)
- Pedro D Maia
- Weill Cornell Medicine, Department of Radiology, New York, NY, USA. .,Weill Cornell Medicine, Brain and Mind Research Institute, New York, NY, USA.
| | - Ashish Raj
- Weill Cornell Medicine, Department of Radiology, New York, NY, USA.,Weill Cornell Medicine, Brain and Mind Research Institute, New York, NY, USA
| | - J Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, 98195-2420, USA
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23
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Long Trace Eyeblink Conditioning Is Largely Preserved in Essential Tremor. THE CEREBELLUM 2019; 18:67-75. [PMID: 29916048 DOI: 10.1007/s12311-018-0956-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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24
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Tarakad A, Jankovic J. Essential Tremor and Parkinson's Disease: Exploring the Relationship. Tremor Other Hyperkinet Mov (N Y) 2019; 8:589. [PMID: 30643667 PMCID: PMC6329774 DOI: 10.7916/d8md0gvr] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/04/2018] [Indexed: 12/31/2022] Open
Abstract
Background There is longstanding controversy surrounding the possible link between essential tremor (ET) and Parkinson's disease (PD). Inconsistent and unreliable diagnostic criteria may in part account for some of the difficulties in defining the relationship between these two common movement disorders. Methods References for this systematic review were identified using PubMed with the search terms "essential tremor" AND "Parkinson's disease" with articles published in English between 1960 and September 2018 included. Results In this review we provide evidence that some patients diagnosed with ET have an increased risk of developing PD years or decades after onset of action tremor. There are several still unresolved questions about the link between the two disorders including lack of verifiable diagnostic criteria for the two disorders and marked overlap in phenomenology. Here we review clinical, epidemiologic, imaging, pathologic, and genetic studies that address the ET-PD relationship. Several lines of evidence support the association between ET and PD, including overlapping motor and non-motor features, relatively high prevalence of rapid eye movement sleep behavior disorder (26-43%) in ET patients, increased prevalence of PD in patients with longstanding antecedent ET, increased prevalence of ET in family members of patients with PD, and the presence of Lewy bodies in the brains of some ET patients (15-24%). Discussion There is a substantial body of evidence supporting the association between ET and PD within at least a subset of patients, although the nature and possible pathogenic mechanisms of the relationship are not well understood.
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Affiliation(s)
- Arjun Tarakad
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
| | - Joseph Jankovic
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
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25
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Lusch B, Weholt J, Maia PD, Kutz JN. Modeling cognitive deficits following neurodegenerative diseases and traumatic brain injuries with deep convolutional neural networks. Brain Cogn 2018; 123:154-164. [PMID: 29597065 DOI: 10.1016/j.bandc.2018.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 11/17/2017] [Accepted: 02/27/2018] [Indexed: 01/10/2023]
Abstract
The accurate diagnosis and assessment of neurodegenerative disease and traumatic brain injuries (TBI) remain open challenges. Both cause cognitive and functional deficits due to focal axonal swellings (FAS), but it is difficult to deliver a prognosis due to our limited ability to assess damaged neurons at a cellular level in vivo. We simulate the effects of neurodegenerative disease and TBI using convolutional neural networks (CNNs) as our model of cognition. We utilize biophysically relevant statistical data on FAS to damage the connections in CNNs in a functionally relevant way. We incorporate energy constraints on the brain by pruning the CNNs to be less over-engineered. Qualitatively, we demonstrate that damage leads to human-like mistakes. Our experiments also provide quantitative assessments of how accuracy is affected by various types and levels of damage. The deficit resulting from a fixed amount of damage greatly depends on which connections are randomly injured, providing intuition for why it is difficult to predict impairments. There is a large degree of subjectivity when it comes to interpreting cognitive deficits from complex systems such as the human brain. However, we provide important insight and a quantitative framework for disorders in which FAS are implicated.
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Affiliation(s)
- Bethany Lusch
- Department of Applied Mathematics, University of Washington, United States.
| | - Jake Weholt
- Department of Applied Mathematics, University of Washington, United States
| | - Pedro D Maia
- Department of Applied Mathematics, University of Washington, United States
| | - J Nathan Kutz
- Department of Applied Mathematics, University of Washington, United States
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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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28
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Maia PD, Kutz JN. Reaction time impairments in decision-making networks as a diagnostic marker for traumatic brain injuries and neurological diseases. J Comput Neurosci 2017; 42:323-347. [PMID: 28393281 DOI: 10.1007/s10827-017-0643-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 02/18/2017] [Accepted: 03/29/2017] [Indexed: 10/19/2022]
Abstract
The presence of diffuse Focal Axonal Swellings (FAS) is a hallmark cellular feature in many neurological diseases and traumatic brain injury. Among other things, the FAS have a significant impact on spike-train encodings that propagate through the affected neurons, leading to compromised signal processing on a neuronal network level. This work merges, for the first time, three fields of study: (i) signal processing in excitatory-inhibitory (EI) networks of neurons via population codes, (ii) decision-making theory driven by the production of evidence from stimulus, and (iii) compromised spike-train propagation through FAS. As such, we demonstrate a mathematical architecture capable of characterizing compromised decision-making driven by cellular mechanisms. The computational model also leads to several novel predictions and diagnostics for understanding injury level and cognitive deficits, including a key finding that decision-making reaction times, rather than accuracy, are indicative of network level damage. The results have a number of translational implications, including that the level of network damage can be characterized by the reaction times in simple cognitive and motor tests.
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Affiliation(s)
- Pedro D Maia
- Department of Applied Mathematics, University of Washington, Seattle, WA, 98195-3925, USA.
| | - J Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, 98195-3925, USA
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Habipoglu Y, Alpua M, Bilkay C, Turkel Y, Dag E. Autonomic dysfunction in patients with essential tremor. Neurol Sci 2016; 38:265-269. [PMID: 27812758 DOI: 10.1007/s10072-016-2754-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/27/2016] [Indexed: 11/29/2022]
Abstract
The aim of this study was to evaluate the autonomic function in patients with essential tremor (ET). Thirty-one adult patients with ET and 26 healthy controls were enrolled in the study. The electrophysiological evaluations of the autonomic nervous system function were performed by sympathetic skin response (SSR) and R-R interval variation (RRIV) tests. The mean latency of SSR in ET patients was significantly delayed compared with the controls (P = 0.01). The mean amplitude of sympathetic skin response was significantly lower in ET patients in comparison to the controls (P = 0.001). No differences were found in mean RRIV values in both group subjects. Sympathetic dysfunction may occur in patients with ET. This may be easily demonstrated by SSR tests.
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Affiliation(s)
- Yasin Habipoglu
- Department of Neurology, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey
| | - Murat Alpua
- Department of Neurology, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey
| | - Cemil Bilkay
- Department of Anatomy, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey
| | - Yakup Turkel
- Department of Neurology, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey.
| | - Ersel Dag
- Department of Neurology, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey
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Bodranghien F, Bastian A, Casali C, Hallett M, Louis ED, Manto M, Mariën P, Nowak DA, Schmahmann JD, Serrao M, Steiner KM, Strupp M, Tilikete C, Timmann D, van Dun K. Consensus Paper: Revisiting the Symptoms and Signs of Cerebellar Syndrome. CEREBELLUM (LONDON, ENGLAND) 2016; 15:369-91. [PMID: 26105056 PMCID: PMC5565264 DOI: 10.1007/s12311-015-0687-3] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cerebellum is involved in sensorimotor operations, cognitive tasks and affective processes. Here, we revisit the concept of the cerebellar syndrome in the light of recent advances in our understanding of cerebellar operations. The key symptoms and signs of cerebellar dysfunction, often grouped under the generic term of ataxia, are discussed. Vertigo, dizziness, and imbalance are associated with lesions of the vestibulo-cerebellar, vestibulo-spinal, or cerebellar ocular motor systems. The cerebellum plays a major role in the online to long-term control of eye movements (control of calibration, reduction of eye instability, maintenance of ocular alignment). Ocular instability, nystagmus, saccadic intrusions, impaired smooth pursuit, impaired vestibulo-ocular reflex (VOR), and ocular misalignment are at the core of oculomotor cerebellar deficits. As a motor speech disorder, ataxic dysarthria is highly suggestive of cerebellar pathology. Regarding motor control of limbs, hypotonia, a- or dysdiadochokinesia, dysmetria, grasping deficits and various tremor phenomenologies are observed in cerebellar disorders to varying degrees. There is clear evidence that the cerebellum participates in force perception and proprioceptive sense during active movements. Gait is staggering with a wide base, and tandem gait is very often impaired in cerebellar disorders. In terms of cognitive and affective operations, impairments are found in executive functions, visual-spatial processing, linguistic function, and affective regulation (Schmahmann's syndrome). Nonmotor linguistic deficits including disruption of articulatory and graphomotor planning, language dynamics, verbal fluency, phonological, and semantic word retrieval, expressive and receptive syntax, and various aspects of reading and writing may be impaired after cerebellar damage. The cerebellum is organized into (a) a primary sensorimotor region in the anterior lobe and adjacent part of lobule VI, (b) a second sensorimotor region in lobule VIII, and (c) cognitive and limbic regions located in the posterior lobe (lobule VI, lobule VIIA which includes crus I and crus II, and lobule VIIB). The limbic cerebellum is mainly represented in the posterior vermis. The cortico-ponto-cerebellar and cerebello-thalamo-cortical loops establish close functional connections between the cerebellum and the supratentorial motor, paralimbic and association cortices, and cerebellar symptoms are associated with a disruption of these loops.
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Affiliation(s)
- Florian Bodranghien
- FNRS ULB-Erasme, Unité d'Etude du Mouvement, 808 Route de Lennik, 1070, Brussels, Belgium
| | - Amy Bastian
- Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD, 21205, USA
| | - Carlo Casali
- Department of Medical and Surgical Sciences and Biotechnologies, Rome Sapienza University, Rome, Italy
| | - Mark Hallett
- Human Motor Control Section, NINDS, Bethesda, MD, USA
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Mario Manto
- FNRS ULB-Erasme, Unité d'Etude du Mouvement, 808 Route de Lennik, 1070, Brussels, Belgium.
| | - Peter Mariën
- Clinical and Experimental Neurolinguistics, CLIN, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Department of Neurology and Memory Clinic, ZNA Middelheim General Hospital, Antwerp, Belgium
| | - Dennis A Nowak
- Helios Klinik Kipfenberg, Kindingerstrasse 13, D-85110, Kipfenberg, Germany
- Neurologische Universitätsklinik, Philipps-Universität Marburg, Baldingerstraße, D-35043, Marburg, Germany
| | - Jeremy D Schmahmann
- Ataxia Unit, Cognitive Behavioural Neurology Unit, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Mariano Serrao
- Department of Medical and Surgical Sciences and Biotechnologies, Rome Sapienza University, Rome, Italy
- Rehabilitation Centre, Movement Analysis LAB, Policlinico Italia, Rome, Italy
| | - Katharina Marie Steiner
- Department of Neurology, University Clinic Essen, Hufelandstrasse 55, 45147, Essen, Germany
- Department of Neurology, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany
| | | | - Caroline Tilikete
- CRNL INSERM U1028 CNRS UMR5292, Team ImpAct, Bron, F-69676, France
- Lyon I University, Lyon, F-69373, France
- Hospices Civils de Lyon, Neuro-Ophthalmology and Neurology D, Hôpital Neurologique Pierre Wertheimer, Bron, F-69677, France
| | - Dagmar Timmann
- Department of Neurology, University Clinic Essen, Hufelandstrasse 55, 45147, Essen, Germany
- Department of Neurology, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany
| | - Kim van Dun
- Department of Neurology and Memory Clinic, ZNA Middelheim General Hospital, Antwerp, Belgium
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Takagishi Y, Katanosaka K, Mizoguchi H, Murata Y. Disrupted axon-glia interactions at the paranode in myelinated nerves cause axonal degeneration and neuronal cell death in the aged Caspr mutant mouse shambling. Neurobiol Aging 2016; 43:34-46. [PMID: 27255813 DOI: 10.1016/j.neurobiolaging.2016.03.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 12/16/2022]
Abstract
Emerging evidence suggests that axonal degeneration is a disease mechanism in various neurodegenerative diseases and that the paranodes at the nodes of Ranvier may be the initial site of pathogenesis. We investigated the pathophysiology of the disease process in the central and peripheral nervous systems of a Caspr mutant mouse, shambling (shm), which is affected by disrupted paranodal structures and impaired nerve conduction of myelinated nerves. The shm mice manifest a progressive neurological phenotype as mice age. We found extensive axonal degeneration and a loss of neurons in the central nervous system and peripheral nervous system in aged shm mice. Axonal alteration of myelinated nerves was defined by abnormal distribution and expression of neurofilaments and derangements in the status of phosphorylated and non/de-phosphorylated neurofilaments. Autophagy-related structures were also accumulated in degenerated axons and neurons. In conclusion, our results suggest that disrupted axon-glia interactions at the paranode cause the cytoskeletal alteration in myelinated axons leading to neuronal cell death, and the process involves detrimental autophagy and aging as factors that promote the pathogenesis.
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Affiliation(s)
- Yoshiko Takagishi
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
| | - Kimiaki Katanosaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Hiroyuki Mizoguchi
- Research Center for Next-Generation Drug Development, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Yoshiharu Murata
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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32
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Fujioka S, Algom AA, Murray ME, Sanchez-Contreras MY, Tacik P, Tsuboi Y, Van Gerpen JA, Uitti RJ, Rademakers R, Ross OA, Wszolek ZK, Dickson DW. Tremor in progressive supranuclear palsy. Parkinsonism Relat Disord 2016; 27:93-7. [PMID: 27039056 DOI: 10.1016/j.parkreldis.2016.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/16/2016] [Accepted: 03/20/2016] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Tremor is thought to be a rare feature of progressive supranuclear palsy (PSP). METHODS We retrospectively reviewed the database of the CurePSP brain bank at Mayo Clinic Florida to retrieve all available clinical information for PSP patients. All patients underwent a standard neuropathological assessment and an immunohistochemical evaluation for tau and α-synuclein. DNA was genotyped for the MAPT H1/H2 haplotype. RESULTS Of the 375 PSP patients identified, 344 had a documented presence or absence of tremor, which included 146 (42%) with tremor, including 29 (20%) with postural/action tremors, 16 (11%) with resting tremor, 7 (5%) with intention tremor, 20 (14%) with a combination of different types of tremor, and 74 (51%) patients who had tremor at some point during their illness, but details were unavailable. The tremor severity of 96% of the patients (54/55) who had this data was minimal to mild. The probability of observing a tremor during a neurological examination during the patient's illness was estimated to be ∼22%. PSP patients with postural/action tremors and PSP patients with resting tremor responded to carbidopa-levodopa therapy more frequently than PSP patients without tremor, although the therapy response was always transient. There were no significant differences in pathological findings between the tremor groups. CONCLUSIONS Tremor is an inconspicuous feature of PSP; however, 42% (146/344) of the PSP patients in our study presented some form of tremor. Because there is no curative therapy for PSP, carbidopa/levodopa therapy should be tried for patients with postural, action, and resting tremor.
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Affiliation(s)
- Shinsuke Fujioka
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA; Department of Neuropathology, 4500 San Pablo Road, Jacksonville, FL 32224, USA; Department of Neuroscience Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA; Department of Neurology, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, Fukuoka 814-0180, Japan.
| | - Avi A Algom
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Melissa E Murray
- Department of Neuropathology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | | | - Pawel Tacik
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Yoshio Tsuboi
- Department of Neurology, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, Fukuoka 814-0180, Japan.
| | - Jay A Van Gerpen
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Ryan J Uitti
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Rosa Rademakers
- Department of Neuroscience Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Owen A Ross
- Department of Neuroscience Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Zbigniew K Wszolek
- Department of Neurology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Dennis W Dickson
- Department of Neuropathology, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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Shill HA, Adler CH, Beach TG. Lewy bodies are incidental in essential tremor. Parkinsonism Relat Disord 2016; 26:81. [PMID: 27010072 DOI: 10.1016/j.parkreldis.2016.02.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 02/29/2016] [Indexed: 10/22/2022]
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Solbach K, Mumm M, Brandauer B, Kronenbürger M, Hermsdörfer J, Timmann D. Prehension Kinematics, Grasping Forces, and Independent Finger Control in Mildly Affected Patients with Essential Tremor. THE CEREBELLUM 2015; 15:498-508. [PMID: 26310449 DOI: 10.1007/s12311-015-0717-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although the pathophysiology of essential tremor (ET), one of the most common movement disorders, is not fully understood, evidence increasingly points to cerebellar involvement. To confirm this connection, we assessed the everyday hand and finger movements of patients with ET, as these movements are known to be affected in cerebellar diseases. In 26 mildly affected patients with ET (compared to age- and gender-matched controls), kinematic and finger force parameters were assessed in a precision grip. In a second task, independent finger movements were recorded. The active finger had to press and release against a force-sensitive keypad while the other fingers stayed inactive. Finally, control of grip force to movement-induced, self-generated load changes was studied. Transport and shaping components during prehension were significantly impaired in patients with ET compared to controls. No significant group differences were observed in independent finger movements and grip force adjustments to self-generated load force changes. However, in the latter two tasks, more severely affected ET patients performed worse than less affected. Although observed deficits in hand and finger movement tasks were small, they are consistent with cerebellar dysfunction in ET. Findings need to be confirmed in future studies examining more severely affected ET patients.
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Affiliation(s)
- Kasja Solbach
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.
| | - Mareike Mumm
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.,Department of Pediatrics, St. Vinzenz-Hospital, Dinslaken, Germany
| | - Barbara Brandauer
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.,Clinical Psychology and Psychotherapy, University of Hamburg, Hamburg, Germany
| | | | - Joachim Hermsdörfer
- Department of Sport and Health Sciences, Institute of Movement Science, Technische Universität München, 80992, Munich, Germany
| | - Dagmar Timmann
- Department of Neurology, University of Duisburg-Essen, Essen, Germany
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Abstract
Essential tremor (ET) is one of the most common neurological diseases, with an estimated 7 million affected individuals in the United States. Postmortem studies in the past few years have resulted in new knowledge as well as a new formulation of disease pathophysiology. This new formulation centers on the notion that ET might be a disease of the cerebellum and, more specifically, the Purkinje cell (PC) population. Indeed, several investigators have proposed that ET may be a "Purkinjopathy." Supporting this formulation are data from controlled postmortem studies demonstrating (1) a range of morphological changes in the PC axon, (2) abnormalities in the position and orientation of PC bodies, (3) reduction in the number of PCs in some studies, (4) morphological changes in and pruning of the PC dendritic arbor with loss of dendritic spines, and (5) alterations in both the PC-basket cell interface and the PC-climbing fiber interface in ET cases. This new formulation has engendered some controversy and raised additional questions. Whether the constellation of changes observed in ET differs from that seen in other degenerative disorders of the cerebellum remains to be determined, although initial studies suggest the likely presence of a distinct profile of changes in ET.
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Affiliation(s)
- Elan D Louis
- Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA
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36
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Louis ED, Kuo SH, Vonsattel JPG, Faust PL. Torpedo formation and Purkinje cell loss: modeling their relationship in cerebellar disease. THE CEREBELLUM 2015; 13:433-9. [PMID: 24590661 DOI: 10.1007/s12311-014-0556-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Torpedo formation and Purkinje cell (PC) loss represent standard and inter-related cerebellar responses to injury. Surprisingly, the nature of their relationship has not been carefully characterized across a range of normal and disease states. Are brains with more torpedoes expected to have fewer PCs? We quantified torpedoes and PCs in four groups: essential tremor (ET), spinocerebellar ataxia (SCA), multiple system atrophy-cerebellar (MSA-C), and controls. Brains from 100 individuals (58 ET, 27 controls, 7 SCA, 8 MSA-C) were available at the New York Brain Bank. After complete neuropathological assessment, a standard parasagittal neocerebellar block was harvested; a 7-μm thick section was stained with Luxol fast blue/hematoxylin and eosin; and torpedoes and PCs were quantified. For a given PC count, SCA and MSA-C cases often had higher torpedo counts than ET cases or controls. Furthermore, the relationship between torpedo and PC counts was complex. The correlation between torpedo and PC counts was negative in ET cases (i.e., individuals with more torpedoes had fewer PCs [i.e., more PC loss]) whereas the relationship was positive in MSA-C cases (i.e., individuals with fewer PCs [i.e., more PC loss] had fewer torpedoes). Patients with SCA showed both patterns. When all diagnostic groups were combined, the correlation was best fit by a quadratic (i.e., parabolic) model rather than a simple linear model; this model incorporated data on the negative correlation in ET cases, the mixed results in SCA cases, and the positive correlation in MSA-C cases (r = 0.636). The relationship between torpedo and PC counts was complex and heterogeneous across a range of cerebellar disease states, and was best characterized by a quadratic rather than a simple model. With more severe cerebellar disease, torpedoes can be quite numerous and are likely a common feature of surviving PCs, but eventually, dramatic loss of PC leads to a paradoxical reduction in observable torpedoes.
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Affiliation(s)
- Elan D Louis
- GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA,
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Larivière R, Gaudet R, Gentil BJ, Girard M, Conte TC, Minotti S, Leclerc-Desaulniers K, Gehring K, McKinney RA, Shoubridge EA, McPherson PS, Durham HD, Brais B. Sacs knockout mice present pathophysiological defects underlying autosomal recessive spastic ataxia of Charlevoix-Saguenay. Hum Mol Genet 2014; 24:727-39. [PMID: 25260547 DOI: 10.1093/hmg/ddu491] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS [MIM 270550]) is an early-onset neurodegenerative disorder caused by mutations in the SACS gene. Over 170 SACS mutations have been reported worldwide and are thought to cause loss of function of sacsin, a poorly characterized and massive 520 kDa protein. To establish an animal model and to examine the pathophysiological basis of ARSACS, we generated Sacs knockout (Sacs(-/-)) mice. Null animals displayed an abnormal gait with progressive motor, cerebellar and peripheral nerve dysfunctions highly reminiscent of ARSACS. These clinical features were accompanied by an early onset, progressive loss of cerebellar Purkinje cells followed by spinal motor neuron loss and peripheral neuropathy. Importantly, loss of sacsin function resulted in abnormal accumulation of non-phosphorylated neurofilament (NF) bundles in the somatodendritic regions of vulnerable neuronal populations, a phenotype also observed in an ARSACS brain. Moreover, motor neurons cultured from Sacs(-/-) embryos exhibited a similar NF rearrangement with significant reduction in mitochondrial motility and elongated mitochondria. The data points to alterations in the NF cytoskeleton and defects in mitochondrial dynamics as the underlying pathophysiological basis of ARSACS.
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Affiliation(s)
- Roxanne Larivière
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
| | - Rébecca Gaudet
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
| | - Benoit J Gentil
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Martine Girard
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | | | - Sandra Minotti
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | | | - Kalle Gehring
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry and
| | - R Anne McKinney
- Department of Pharmacology, McGill University, Montreal, QC, Canada H3G 0B1
| | - Eric A Shoubridge
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Heather D Durham
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
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Schmouth JF, Dion PA, Rouleau GA. Genetics of essential tremor: From phenotype to genes, insights from both human and mouse studies. Prog Neurobiol 2014; 119-120:1-19. [DOI: 10.1016/j.pneurobio.2014.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/16/2014] [Accepted: 05/02/2014] [Indexed: 11/30/2022]
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Symanski C, Shill HA, Dugger B, Hentz JG, Adler CH, Jacobson SA, Driver-Dunckley E, Beach TG. Essential tremor is not associated with cerebellar Purkinje cell loss. Mov Disord 2014; 29:496-500. [PMID: 24532134 DOI: 10.1002/mds.25845] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/26/2013] [Accepted: 01/12/2014] [Indexed: 11/06/2022] Open
Abstract
There has been controversy as to whether there is an underlying neurodegenerative process of the cerebellum in essential tremor (ET). The aim of this study was to examine whether ET is associated with Purkinje cell (PC) loss. Prospectively categorized ET and control subjects who were longitudinally examined in the Arizona Study for Aging and Neurodegenerative Disorders and came to autopsy between 1998 and 2013 underwent standardized neuropathological assessment of the brain. PC linear density of the cerebellar hemisphere was calculated in a blinded manner. There were 56 ET cases and 62 age-matched controls free of dementia and other neurodegenerative disorders included in the study. Mean PC linear density was 3.80 ± 0.81 cells per mm for tremor cases and 3.82 ± 0.91 cells per mm for controls (Δ 0.02; 95% confidence interval [CI]: -0.30-0.34). PC counts were not associated with tremor duration (r = 0.06; 95% CI: -0.21-0.32). These data demonstrate that ET is not associated with cerebellar PC loss.
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Affiliation(s)
- Claire Symanski
- Cleo Roberts Center, Banner Sun Health Research Institute, Sun City, Arizona, USA
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Haubenberger D, Nahab FB, Voller B, Hallett M. Treatment of essential tremor with long-chain alcohols: still experimental or ready for prime time? Tremor Other Hyperkinet Mov (N Y) 2014; 4:tre-04-211-4673-2. [PMID: 24587968 PMCID: PMC3918508 DOI: 10.7916/d8rx991r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/31/2013] [Indexed: 12/30/2022] Open
Abstract
AIM To review current literature on long-chain alcohols and their derivatives as novel pharmacotherapy for the treatment of essential tremor (ET). BACKGROUND Currently available and recommended pharmacotherapies for ET are often limited by suboptimal treatment effects, frequent adverse effects, and drug interactions. While ethanol is reported to profoundly decrease tremor severity in the majority of patients with ET, preclinical experience suggests that long-chain alcohols such as 1-octanol might lead to a comparable tremor reduction without ethanol's typical side effects of sedation and intoxication. Here, we review the literature on the first clinical trials on 1-octanol and its metabolite octanoic acid (OA) for the treatment of ET. METHODS The literature on preclinical and clinical trials on long-chain alcohols as well as OA was reviewed and summarized, and an outlook given on next phases of development. DISCUSSION 1-octanol was demonstrated to be safe and effective in a double-blind, placebo-controlled low-dose trial, and open-label data showed excellent tolerability and dose-dependent efficacy up to 128 mg/kg. Despite 1-octanol's efficacy, its future viability as an effective therapy is limited by its pharmacological properties that require large volumes to be orally administered. Pharmacokinetic data indicate that OA is the active metabolite of 1-octanol. Preclinical efficacy data for OA are positive, and human pilot data demonstrated excellent safety as well as efficacy in secondary outcome measures of tremor amplitudes. OA also has more favorable pharmacological properties for drug delivery; hence, OA may be worth developing as a pharmaceutical.
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Affiliation(s)
- Dietrich Haubenberger
- Department of Neurology, Medical University of Vienna, Vienna, Austria
- Human Motor Control Section, Medical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Fatta B. Nahab
- Movement Disorders Center, Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Bernhard Voller
- Department of Neurology, Medical University of Vienna, Vienna, Austria
- Human Motor Control Section, Medical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
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Abstract
Classic essential tremor is a clinical syndrome of action tremor in the upper limbs (at least 95 % of patients) and less commonly the head, face/jaw, voice, tongue, trunk, and lower limbs, in the absence of other neurologic signs. However, the longstanding notion that essential tremor is a monosymptomatic tremor disorder is being challenged by a growing literature describing associated disturbances of tandem walking, personality, mood, hearing, and cognition. There is also epidemiologic, pathologic, and genetic evidence that essential tremor is pathophysiologically heterogeneous. Misdiagnosis of essential tremor is common because clinicians frequently overlook other neurologic signs and because action tremor in the hands is caused by many conditions, including dystonia, Parkinson disease, and drug-induced tremor. Thus, essential tremor is nothing more than a syndrome of idiopathic tremulousness, and the challenge for researchers and clinicians is to find specific etiologies of this syndrome.
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Mao X, Wang T, Liu M, Chang X, Li N, Gu Y, Zhao D, Liao Q, Peng R. Meta-analysis of the influence of DRD3 Ser9Gly variant on susceptibility for essential tremor. J Clin Neurosci 2013; 20:1644-9. [PMID: 24054403 DOI: 10.1016/j.jocn.2013.03.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/06/2013] [Accepted: 03/10/2013] [Indexed: 02/05/2023]
Abstract
The dopamine D3 receptor (DRD3) Ser9Gly variant has attracted more attention since the variant was observed to be associated with risk of essential tremor (ET). A number of association studies concerning the DRD3 Ser9Gly variant and ET susceptibility have been conducted in various populations. However, some results were contradictory. To derive a more precise estimation of the relationship between the DRD3 Ser9Gly variant and the genetic risk of ET, we performed a comprehensive meta-analysis which included seven case-control studies. The meta-analysis was conducted in four genetic models: dominant, recessive, heterozygous, and homozygous. The odds ratio and 95% confidence intervals were used as the measure of association. The combined results of overall analysis showed a lack of association of the DRD3 Ser9Gly variant and ET, regardless of the genetic model of Ser9Gly. Publication bias and heterogeneity were absent in most analyses. In conclusion, the present meta-analysis does not support the notion that the DRD3 Ser9Gly variant is a genetic risk factor for ET.
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Affiliation(s)
- Xueye Mao
- Department of Neurology, West China Hospital, Sichuan University, 37 Guo Xue Road, Chengdu 610041, Sichuan Province, China
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Saifee TA, Edwards MJ. A normal inferior olive in essential tremor--peacemaker or pacemaker? Mov Disord 2013; 28:694-6. [PMID: 23728621 DOI: 10.1002/mds.25485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/12/2013] [Accepted: 04/01/2013] [Indexed: 11/05/2022] Open
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Imataka G, Yamanouchi H, Hirato J, Eguchi M, Kojima M, Honma K, Arisaka O. Autopsy report of a 7-year old patient with the mosaic trisomy 13. Cell Biochem Biophys 2013; 67:813-7. [PMID: 23526188 PMCID: PMC3825528 DOI: 10.1007/s12013-013-9567-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We present here a long survival case of a patient with the mosaic form of trisomy 13 who died of aspiration pneumonia at the age of 7 years and 4 months. The autopsy revealed olfactory aplasia and fenestration of the septum pellucidum, and dilated lateral ventricles and atrophic hippocampus. Furthermore, there were numerous "torpedos" (i.e., swollen fusiform Purkinje cell axons), mostly in the granular layer underneath the Purkinje cell layer, and, occasionally, in the granular layer. Similar neuropathological findings have been reported in elderly cases of essential tremor, Parkinson's disease, or Alzheimer's disease. Precise mechanism for this axonal change is still unclear. These pathological changes have never previously been reported in the literature on trisomy 13, and the present patient is one of the oldest autopsied individuals with the mosaic trisomy 13.
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Affiliation(s)
- George Imataka
- Department of Pediatrics, Dokkyo Medical University School of Medicine, 880 Mibu, Shimotsuga, Tochigi, 321-0293, Japan,
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Abstract
The pathology of essential tremor (ET) is increasingly being studied. The main findings include a reduction in cerebellar Purkinje cells, other pathological changes of cerebellar degeneration and restricted Lewy bodies in the locus ceruleus. This paper will review those findings and put them into context with clinical studies in ET and findings in neurodegenerative disorders such as Parkinson's disease.
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Affiliation(s)
- Holly A Shill
- Banner Sun Health Research Institute, Sun City, AZ, USA.
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46
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Essential tremor is a neurodegenerative disease. J Neural Transm (Vienna) 2012; 119:1383-7; discussion 1373. [DOI: 10.1007/s00702-012-0878-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 07/25/2012] [Indexed: 10/28/2022]
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Rajput AH, Adler CH, Shill HA, Rajput A. Essential tremor is not a neurodegenerative disease. Neurodegener Dis Manag 2012; 2:259-268. [PMID: 23105950 DOI: 10.2217/nmt.12.23] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The pathophysiology of essential tremor (ET) remains unknown. Standard neuropathological studies have reported no consistent changes but a detailed study found neurodegeneration in all ET cases - 24% demonstrated lower brainstem Lewy body (LB) inclusions and 76% experienced a loss of cerebellar Purkinje cells (PCs) and its sequelae. We review the evidence on neurodegeneration in ET. The prevalence of LB inclusions in ET brains is similar to that in the asymptomatic general population. These incidental LB disease cases have evidence for reduced striatal tyrosine hydroxylase levels, as found in Parkinson's disease, but there is no evidence for reduced tyrosine hydroxylase levels in ET patients. Reduced mean PC counts in ET cases compared with the controls reported by some studies could not be replicated by others. Most ET cases have the same number of PCs as controls of a comparable age. Neither the lower brainstem LB inclusions nor the cerebellar PC loss represent the neurodegenerative basis of ET. Further studies are needed to determine the pathophysiology of ET.
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Affiliation(s)
- Ali H Rajput
- Movement Disorders Program, Neurology Division, University of Saskatchewan/Saskatoon Health Region, 103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada
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Lax NZ, Hepplewhite PD, Reeve AK, Nesbitt V, McFarland R, Jaros E, Taylor RW, Turnbull DM. Cerebellar ataxia in patients with mitochondrial DNA disease: a molecular clinicopathological study. J Neuropathol Exp Neurol 2012; 71:148-61. [PMID: 22249460 PMCID: PMC3272439 DOI: 10.1097/nen.0b013e318244477d] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cerebellar ataxia is a prominent clinical symptom in patients with mitochondrial DNA (mtDNA) disease. This is often progressive with onset in young adulthood. We performed a detailed neuropathologic investigation of the olivary-cerebellum in 14 genetically and clinically well-defined patients with mtDNA disease. Quantitative neuropathologic investigation showed varying levels of loss of Purkinje cells and neurons of the dentate nucleus and inferior olivary nuclei. Typically, focal Purkinje cell loss was present in patients with the m.3243A>G mutation caused by the presence of microinfarcts, with relative preservation of neuronal cell populations in the olivary and dentate nuclei. In contrast, patients with the m.8344A>G mutation or recessive POLG mutations showed extensive and global neuronal cell loss in all 3 olivary-cerebellum areas examined. Molecular analysis of mutated mtDNA heteroplasmy levels revealed that neuronal cell loss occurred independently of the level of mutated mtDNA present within surviving neurons. High levels of neuronal respiratory chain deficiency, particularly of complex I, were detected in surviving cells; levels of deficiency were greater in regions with extensive cell loss. We found a relationship between respiratory deficiency and neuronal cell density, indicating that neuronal cell death correlates with respiratory deficiency. These findings highlight the vulnerability of the olivary-cerebellum to mtDNA defects.
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Affiliation(s)
- Nichola Zoe Lax
- Mitochondrial Research Group, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom
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50
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Paris-Robidas S, Brochu E, Sintes M, Emond V, Bousquet M, Vandal M, Pilote M, Tremblay C, Di Paolo T, Rajput AH, Rajput A, Calon F. Defective dentate nucleus GABA receptors in essential tremor. ACTA ACUST UNITED AC 2011; 135:105-16. [PMID: 22120148 DOI: 10.1093/brain/awr301] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The development of new treatments for essential tremor, the most frequent movement disorder, is limited by a poor understanding of its pathophysiology and the relative paucity of clinicopathological studies. Here, we report a post-mortem decrease in GABA(A) (35% reduction) and GABA(B) (22-31% reduction) receptors in the dentate nucleus of the cerebellum from individuals with essential tremor, compared with controls or individuals with Parkinson's disease, as assessed by receptor-binding autoradiography. Concentrations of GABA(B) receptors in the dentate nucleus were inversely correlated with the duration of essential tremor symptoms (r(2) = 0.44, P < 0.05), suggesting that the loss of GABA(B) receptors follows the progression of the disease. In situ hybridization experiments also revealed a diminution of GABA(B(1a+b)) receptor messenger RNA in essential tremor (↓27%). In contrast, no significant changes of GABA(A) and GABA(B) receptors (protein and messenger RNA), GluN2B receptors, cytochrome oxidase-1 or GABA concentrations were detected in molecular or granular layers of the cerebellar cortex. It is proposed that a decrease in GABA receptors in the dentate nucleus results in disinhibition of cerebellar pacemaker output activity, propagating along the cerebello-thalamo-cortical pathways to generate tremors. Correction of such defective cerebellar GABAergic drive could have a therapeutic effect in essential tremor.
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