1
|
Benarroch E. What Is the Role of the Dentate Nucleus in Normal and Abnormal Cerebellar Function? Neurology 2024; 103:e209636. [PMID: 38954796 DOI: 10.1212/wnl.0000000000209636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
|
2
|
Yang Y, Zheng C, Chen B, Hernandez NC, Faust PL, Cai Z, Louis ED, Matuskey D. Decreased Synaptic Vesicle Glycoprotein 2A Binding in the Human Postmortem Essential Tremor Cerebellum: Evidence of Reduction in Synaptic Density. CEREBELLUM (LONDON, ENGLAND) 2024; 23:1053-1060. [PMID: 37783917 DOI: 10.1007/s12311-023-01611-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/27/2023] [Indexed: 10/04/2023]
Abstract
OBJECTIVE Despite being one of the most prevalent neurological diseases, the pathophysiology of essential tremor (ET) is not fully understood. Neuropathological studies have identified numerous degenerative changes in the cerebellum of ET patients, however. These data align with considerable clinical and neurophysiological data linking ET to the cerebellum. While neuroimaging studies have variably shown mild atrophy in the cerebellum, marked atrophy is not a clear feature of the cerebellum in ET and a search for a more suitable neuroimaging signature of neurodegeneration is in order. Postmortem studies in ET have examined different neuropathological alterations in the cerebellum, but as of yet have not focused on measures of generalized synaptic markers. This pilot study focuses on synaptic vesicle glycoprotein 2A (SV2A), a protein expressed in practically all synapses in the brain, as a measure of synaptic density in postmortem ET cases. METHODS The current study utilized autoradiography with the SV2A radioligand [18F]SDM-16 to assess synaptic density in the cerebellar cortex and dentate nucleus in three ET cases and three age-matched controls. RESULTS Using [18F]SDM-16, SV2A was 53% and 46% lower in the cerebellar cortex and dentate nucleus, respectively, in ET cases compared to age-matched controls. CONCLUSION In this pilot study, using in vitro SV2A autoradiography, we have observed significantly lower synaptic density in the cerebellar cortex and dentate nucleus of ET cases. Future research could expand on our sample size and focus on in vivo imaging in ET to explore whether SV2A imaging could serve as a much-needed disease biomarker.
Collapse
Affiliation(s)
- Yanghong Yang
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Chao Zheng
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Baosheng Chen
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Nora C Hernandez
- Department of Neurology, University of Texas Southwestern School of Medicine, Dallas, TX, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, New York, NY, USA
| | - Zhengxin Cai
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern School of Medicine, Dallas, TX, USA
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.
| |
Collapse
|
3
|
Sharifi S, Buijink AWG, Luft F, Scheijbeler EP, Potters WV, van Wingen G, Heida T, Bour LJ, van Rootselaar AF. Differences in Olivo-Cerebellar Circuit and Cerebellar Network Connectivity in Essential Tremor: a Resting State fMRI Study. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1123-1136. [PMID: 36214998 PMCID: PMC10657290 DOI: 10.1007/s12311-022-01486-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
The olivo-cerebellar circuit is thought to play a crucial role in the pathophysiology of essential tremor (ET). Whether olivo-cerebellar circuit dysfunction is also present at rest, in the absence of clinical tremor and linked voluntary movement, remains unclear. Assessing this network in detail with fMRI is challenging, considering the brainstem is close to major arteries and pulsatile cerebrospinal fluid-filled spaces obscuring signals of interest. Here, we used methods tailored to the analysis of infratentorial structures. We hypothesize that the olivo-cerebellar circuit shows altered intra-network connectivity at rest and decreased functional coupling with other parts of the motor network in ET. In 17 ET patients and 19 healthy controls, we investigated using resting state fMRI intracerebellar functional and effective connectivity on a dedicated cerebellar atlas. With independent component analysis, we investigated data-driven cerebellar motor network activations during rest. Finally, whole-brain connectivity of cerebellar motor structures was investigated using identified components. In ET, olivo-cerebellar pathways show decreased functional connectivity compared with healthy controls. Effective connectivity analysis showed an increased inhibitory influence of the dentate nucleus towards the inferior olive. Cerebellar independent component analyses showed motor resting state networks are less strongly connected to the cerebral cortex compared to controls. Our results indicate the olivo-cerebellar circuit to be affected at rest. Also, the cerebellum is "disconnected" from the rest of the motor network. Aberrant activity, generated within the olivo-cerebellar circuit could, during action, spread towards other parts of the motor circuit and potentially underlie the characteristic tremor of this patient group.
Collapse
Affiliation(s)
- Sarvi Sharifi
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands.
| | - Arthur W G Buijink
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Frauke Luft
- Department of Biomedical Signals and Systems, University of Twente, TechMed Centre, Enschede, The Netherlands
| | - Elliz P Scheijbeler
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location Vrije Universiteit Amsterdam, Boelelaan 1117, Amsterdam, The Netherlands
| | - Wouter V Potters
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Guido van Wingen
- Department of Psychiatry, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Tjitske Heida
- Department of Biomedical Signals and Systems, University of Twente, TechMed Centre, Enschede, The Netherlands
| | - Lo J Bour
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Anne-Fleur van Rootselaar
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| |
Collapse
|
4
|
Bal N, Şengül Y, Behmen MB, Powell A, Louis ED. Vestibular reflexes in essential tremor: abnormalities of ocular and cervical vestibular-evoked myogenic potentials are associated with the cerebellum and brainstem involvement. J Neural Transm (Vienna) 2023; 130:1553-1559. [PMID: 37199795 DOI: 10.1007/s00702-023-02652-3] [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: 03/29/2023] [Accepted: 05/12/2023] [Indexed: 05/19/2023]
Abstract
This study utilized cervical vestibular-evoked myogenic potentials tests (cVEMP) and ocular vestibular-evoked myogenic potentials tests (oVEMP) to investigate the vestibulocollic and vestibuloocular reflex arcs and to evaluate cerebellar and brainstem involvement) in essential tremor (ET). Eighteen cases with ET and 16 age- and gender-matched healthy control subjects (HCS) were included in the present study. Otoscopic and neurologic examinations were performed on all participants, and both cervical and ocular VEMP tests were performed. Pathological cVEMP results were increased in the ET group (64.7%) compared to the HCS (41,2%; p > 0.05). The latencies of P1 and N1 waves were shorter in the ET group than in HCS (p = 0.01 and p = 0.001). Pathological oVEMP responses were significantly higher in the ET group (72.2%) compared to the HCS (37.5%; p = 0.01). There was no statistically significant difference in oVEMP N1-P1 latencies between groups (p > 0.05). Because the ET group had high pathological responses to the oVEMP, but not the cVEMP, the upper brainstem pathways may be more affected by ET.
Collapse
Affiliation(s)
- Nilüfer Bal
- Department of Audiology, Faculty of Health Sciences, Bezmialem Vakıf University, Istanbul, Turkey.
- Subdepartment of Audiology, Department of Otolarygology, Faculty of Medicine, Subdepartment of Audiology, Marmara University, Istanbul, Turkey.
| | - Yıldızhan Şengül
- Department of Neurology, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Meliha Başöz Behmen
- Department of Audiology, Faculty of Health Sciences, Bezmialem Vakıf University, Istanbul, Turkey
| | - Allison Powell
- Department of Neurology, University Texas Southwestern Med. Center, Dallas, Texas, USA
| | - Elan D Louis
- Department of Neurology, University Texas Southwestern Med. Center, Dallas, Texas, USA
| |
Collapse
|
5
|
Martuscello RT, Sivaprakasam K, Hartstone W, Kuo SH, Konopka G, Louis ED, Faust PL. Gene Expression Analysis of Laser-Captured Purkinje Cells in the Essential Tremor Cerebellum. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1166-1181. [PMID: 36242761 PMCID: PMC10359949 DOI: 10.1007/s12311-022-01483-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 12/13/2022]
Abstract
Essential tremor (ET) is a common, progressive neurological disease characterized by an 8-12-Hz kinetic tremor. Despite its high prevalence, the patho-mechanisms of tremor in ET are not fully known. Through comprehensive studies in postmortem brains, we identified major morphological changes in the ET cerebellum that reflect cellular damage in Purkinje cells (PCs), suggesting that PC damage is central to ET pathogenesis. We previously performed a transcriptome analysis in ET cerebellar cortex, identifying candidate genes and several dysregulated pathways. To directly target PCs, we purified RNA from PCs isolated by laser capture microdissection and performed the first ever PC-specific RNA-sequencing analysis in ET versus controls. Frozen postmortem cerebellar cortex from 24 ETs and 16 controls underwent laser capture microdissection, obtaining ≥2000 PCs per sample. RNA transcriptome was analyzed via differential gene expression, principal component analysis (PCA), and gene set enrichment analyses (GSEA). We identified 36 differentially expressed genes, encompassing multiple cellular processes. Some ET (13/24) had greater dysregulation of these genes and segregated from most controls and remaining ETs in PCA. Characterization of genes/pathways enriched in this PCA and GSEA identified multiple pathway dysregulations in ET, including RNA processing/splicing, synapse organization/ion transport, and oxidative stress/inflammation. Furthermore, a different set of pathways characterized marked heterogeneity among ET patients. Our data indicate a range of possible mechanisms for the pathogenesis of ET. Significant heterogeneity among ET combined with dysregulation of multiple cellular processes supports the notion that ET is a family of disorders rather than one disease entity.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA
| | - Karthigayini Sivaprakasam
- Peter O'Donnell Jr. Brain Institute, Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Whitney Hartstone
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, 650 W 168th Street, BB302, New York, NY, USA
| | - Genevieve Konopka
- Peter O'Donnell Jr. Brain Institute, Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Suite NL9.114, Dallas, TX, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, 10032, USA.
| |
Collapse
|
6
|
Martuscello RT, Chen ML, Reiken S, Sittenfeld LR, Ruff DS, Ni CL, Lin CC, Pan MK, Louis ED, Marks AR, Kuo SH, Faust PL. Defective cerebellar ryanodine receptor type 1 and endoplasmic reticulum calcium 'leak' in tremor pathophysiology. Acta Neuropathol 2023; 146:301-318. [PMID: 37335342 PMCID: PMC10350926 DOI: 10.1007/s00401-023-02602-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 06/21/2023]
Abstract
Essential Tremor (ET) is a prevalent neurological disease characterized by an 8-10 Hz action tremor. Molecular mechanisms of ET remain poorly understood. Clinical data suggest the importance of the cerebellum in disease pathophysiology, and pathological studies indicate Purkinje Cells (PCs) incur damage. Our recent cerebellar cortex and PC-specific transcriptome studies identified alterations in calcium (Ca2+) signaling pathways that included ryanodine receptor type 1 (RyR1) in ET. RyR1 is an intracellular Ca2+ release channel located on the Endoplasmic Reticulum (ER), and in cerebellum is predominantly expressed in PCs. Under stress conditions, RyR1 undergoes several post-translational modifications (protein kinase A [PKA] phosphorylation, oxidation, nitrosylation), coupled with depletion of the channel-stabilizing binding partner calstabin1, which collectively characterize a "leaky channel" biochemical signature. In this study, we found markedly increased PKA phosphorylation at the RyR1-S2844 site, increased RyR1 oxidation and nitrosylation, and calstabin1 depletion from the RyR1 complex in postmortem ET cerebellum. Decreased calstabin1-RyR1-binding affinity correlated with loss of PCs and climbing fiber-PC synapses in ET. This 'leaky' RyR1 signature was not seen in control or Parkinson's disease cerebellum. Microsomes from postmortem cerebellum demonstrated excessive ER Ca2+ leak in ET vs. controls, attenuated by channel stabilization. We further studied the role of RyR1 in tremor using a mouse model harboring a RyR1 point mutation that mimics constitutive site-specific PKA phosphorylation (RyR1-S2844D). RyR1-S2844D homozygous mice develop a 10 Hz action tremor and robust abnormal oscillatory activity in cerebellar physiological recordings. Intra-cerebellar microinfusion of RyR1 agonist or antagonist, respectively, increased or decreased tremor amplitude in RyR1-S2844D mice, supporting a direct role of cerebellar RyR1 leakiness for tremor generation. Treating RyR1-S2844D mice with a novel RyR1 channel-stabilizing compound, Rycal, effectively dampened cerebellar oscillatory activity, suppressed tremor, and normalized cerebellar RyR1-calstabin1 binding. These data collectively support that stress-associated ER Ca2+ leak via RyR1 may contribute to tremor pathophysiology.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, 630 W 168th Street, PH Stem 15-124, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Meng-Ling Chen
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - Leah R Sittenfeld
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - David S Ruff
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Chun-Lun Ni
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Chih-Chun Lin
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Ming-Kai Pan
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, USA
| | - Andrew R Marks
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, 1150 St Nicholas Ave, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 650 W 168th Street, BB305, New York, NY, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, 630 W 168th Street, PH Stem 15-124, New York, NY, 10032, USA.
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA.
| |
Collapse
|
7
|
Olivier C, Lamy JC, Kosutzka Z, Van Hamme A, Cherif S, Lau B, Vidailhet M, Karachi C, Welter ML. Cerebellar Transcranial Alternating Current Stimulation in Essential Tremor Patients with Thalamic Stimulation: A Proof-of-Concept Study. Neurotherapeutics 2023; 20:1109-1119. [PMID: 37097344 PMCID: PMC10457262 DOI: 10.1007/s13311-023-01372-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2023] [Indexed: 04/26/2023] Open
Abstract
Essential tremor (ET) is a disabling condition resulting from a dysfunction of cerebello-thalamo-cortical circuitry. Deep brain stimulation (DBS) or lesion of the ventral-intermediate thalamic nucleus (VIM) is an effective treatment for severe ET. Transcranial cerebellar brain stimulation has recently emerged as a non-invasive potential therapeutic option. Here, we aim to investigate the effects of high-frequency non-invasive cerebellar transcranial alternating current stimulation (tACS) in severe ET patients already operated for VIM-DBS. Eleven ET patients with VIM-DBS, and 10 ET patients without VIM-DBS and matched for tremor severity, were included in this double-blind proof-of-concept controlled study. All patients received unilateral cerebellar sham-tACS and active-tACS for 10 min. Tremor severity was blindly assessed at baseline, without VIM-DBS, during sham-tACS, during and at 0, 20, 40 min after active-tACS, using kinetic recordings during holding posture and action ('nose-to-target') task and videorecorded Fahn-Tolosa-Marin (FTM) clinical scales. In the VIM-DBS group, active-tACS significantly improved both postural and action tremor amplitude and clinical (FTM scales) severity, relative to baseline, whereas sham-tACS did not, with a predominant effect for the ipsilateral arm. Tremor amplitude and clinical severity were also not significantly different between ON VIM-DBS and active-tACS conditions. In the non-VIM-DBS group, we also observed significant improvements in ipsilateral action tremor amplitude, and clinical severity after cerebellar active-tACS, with a trend for improved postural tremor amplitude. In non-VIM-DBS group, sham- active-tACS also decreased clinical scores. These data support the safety and potential efficacy of high-frequency cerebellar-tACS to reduce ET amplitude and severity.
Collapse
Affiliation(s)
- Claire Olivier
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- PANAM Core Facility, Institut du Cerveau - Paris Brain Institute, Paris, France
| | - Jean-Charles Lamy
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- PANAM Core Facility, Institut du Cerveau - Paris Brain Institute, Paris, France
- Department of Neurology, AP-HP, Hôpital Salpetriere, DMU Neuroscience 6, Paris, France
| | - Zuzana Kosutzka
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- Department of Neurology, AP-HP, Hôpital Salpetriere, DMU Neuroscience 6, Paris, France
| | - Angèle Van Hamme
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- PANAM Core Facility, Institut du Cerveau - Paris Brain Institute, Paris, France
| | - Saoussen Cherif
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
| | - Brian Lau
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
| | - Marie Vidailhet
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- Department of Neurology, AP-HP, Hôpital Salpetriere, DMU Neuroscience 6, Paris, France
| | - Carine Karachi
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France
- Department of Neurosurgery, AP-HP, Hôpital Salpetriere, Paris, France
| | - Marie-Laure Welter
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, 47 Bd de L'Hôpital, 75013, Paris, France.
- PANAM Core Facility, Institut du Cerveau - Paris Brain Institute, Paris, France.
- Clinical Investigation Center, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France.
- Department of Neurophysiology, Rouen University Hospital, University of Rouen, Rouen, France.
| |
Collapse
|
8
|
Yang Y, Zheng C, Chen B, Hernandez NC, Faust PL, Cai Z, Louis ED, Matuskey D. Decreased Synaptic Vesicle Glycoprotein 2A Binding in the Human Postmortem Essential Tremor Cerebellum: Evidence of Reduction in Synaptic Density. RESEARCH SQUARE 2023:rs.3.rs-2838184. [PMID: 37205584 PMCID: PMC10187382 DOI: 10.21203/rs.3.rs-2838184/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Objective Despite being one of the most prevalent neurological diseases, the pathophysiology of essential tremor (ET) is not fully understood. Neuropathological studies have identified numerous degenerative changes in the cerebellum of ET patients, however. These data align with considerable clinical and neurophysiological data linking ET to the cerebellum. While neuroimaging studies have variably shown mild atrophy in the cerebellum, marked atrophy is not a clear feature of the cerebellum in ET and that a search for a more suitable neuroimaging signature of neurodegeneration is in order. Postmortem studies in ET have examined different neuropathological alterations in the cerebellum, but as of yet have not focused on measures of generalized synaptic markers. This pilot study focuses on synaptic vesicle glycoprotein 2A (SV2A), a protein expressed in practically all synapses in the brain, as a measure of synaptic density in postmortem ET cases. Methods The current study utilized autoradiography with the SV2A radioligand [ 18 F]SDM-16 to assess synaptic density in the cerebellar cortex and dentate nucleus in three ET cases and three age-matched controls. Results Using [ 18 F]SDM-16, SV2A was 53% and 46% lower in the cerebellar cortex and dentate nucleus, respectively, in ET cases compared to age-matched controls. Conclusion For the first time, using in vitro SV2A autoradiography, we have observed significantly lower synaptic density in the cerebellar cortex and dentate nucleus of ET cases. Future research could focus on in vivo imaging in ET to explore whether SV2A imaging could serve as a much-needed disease biomarker.
Collapse
Affiliation(s)
| | | | | | | | - Phyllis L Faust
- Columbia University Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital
| | | | - Elan D Louis
- University of Texas Southwestern School of Medicine
| | | |
Collapse
|
9
|
Sondergaard RE, Strzalkowski NDJ, Gan LS, Jasaui Y, Furtado S, Pringsheim TM, Sarna JR, Avanzino L, Kiss ZHT, Martino D. Cerebellar Brain Inhibition Is Associated With the Severity of Cervical Dystonia. J Clin Neurophysiol 2023; 40:293-300. [PMID: 34334683 DOI: 10.1097/wnp.0000000000000884] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Cerebellar connectivity is thought to be abnormal in cervical dystonia (CD) and other dystonia subtypes, based on evidence from imaging studies and animal work. The authors investigated whether transcranial magnetic stimulation-induced cerebellar brain inhibition (CBI), a measure of cerebellar efficiency at inhibiting motor outflow, is abnormal in patients with CD and/or is associated with clinical features of CD. Because of methodological heterogeneity in CBI reporting, the authors deployed additional controls to reduce potential sources of variability in this study. METHODS Cerebellar brain inhibition was applied in 20 CD patients and 14 healthy control subjects. Cerebellar brain inhibition consisted of a cerebellar conditioning stimulus delivered at four different interstimulus intervals (ISIs) before a test stimulus delivered to hand muscle representation in the motor cortex. The average ratio of conditioned to unconditioned motor evoked potential was computed for each ISI. Cervical dystonia clinical severity was measured using the Toronto Western Spasmodic Torticollis Rating Scale. Control experiments involved neuronavigated transcranial magnetic stimulation, neck postural control in patients, and careful screening for noncerebellar pathway inhibition via cervicomedullary evoked potentials. RESULTS There was no difference between CBI measured in healthy control subjects and CD patients at any of the four ISIs; however, CBI efficiency was significantly correlated with worsening CD clinical severity at the 5 ms ISI. CONCLUSIONS Cerebellar brain inhibition is a variable measure in both healthy control subjects and CD patients; much of this variability may be attributed to experimental methodology. Yet, CD severity is significantly associated with reduced CBI at the 5 ms ISI, suggestive of cerebello-thalamo-cortical tract dysfunction in this disorder.
Collapse
Affiliation(s)
- Rachel E Sondergaard
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Calgary, AB, Canada
| | - Nicholas D J Strzalkowski
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Calgary, AB, Canada
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada
| | - Liu Shi Gan
- Hotchkiss Brain Institute, Calgary, AB, Canada
| | - Yamile Jasaui
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Sarah Furtado
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Tamara M Pringsheim
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Calgary, AB, Canada
- Department of Psychiatry, Pediatrics and Community Healthy Sciences, University of Calgary, Calgary, AB, Canada
| | - Justyna R Sarna
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Laura Avanzino
- Department of Experimental Medicine, Section of Human Physiology, University of Genoa, Genoa, Italy; and
- IRCCS Policlinico, San Martino, Genova
| | - Zelma H T Kiss
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Calgary, AB, Canada
| | - Davide Martino
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Calgary, AB, Canada
| |
Collapse
|
10
|
Louis ED. Essential tremor. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:389-401. [PMID: 37620080 DOI: 10.1016/b978-0-323-98817-9.00012-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Essential tremor (ET) is a chronic and progressive neurologic disease. Its central and defining clinical feature is a 4-12Hz kinetic tremor, that is, tremor that occurs during voluntary movements such as drinking from a cup or writing. Patients may also exhibit a range of other tremors-postural, rest, intention, additional motor features (e.g., mild gait ataxia, mild dystonia), as well as nonmotor features. The disease itself seems to be a risk factor for other degenerative diseases such as Alzheimer's disease and Parkinson's disease. Both genetic and toxic environmental factors have been explored as etiologic factors. In addition to a growing appreciation of the presence of clinical, etiologic, and pathologic heterogeneity, there is some support for the notion that ET itself may not be a single disease, but may be a family of diseases whose central defining feature is kinetic tremor of the arms, and which might more accurately be referred to as "the essential tremors." Recent research has increasingly placed the seat of the disease in the cerebellum and cerebellar system and identified a host of neurodegenerative changes within the cerebellum, indicating that this progressive disorder is likely degenerative.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| |
Collapse
|
11
|
Muruzheva ZM, Traktirov DS, Tumashova OS, Karpenko MN. Cluster analysis of clinical, biochemical and electrophysiological features of essential tremor patients. Exploratory study. Clin Neurol Neurosurg 2022; 222:107472. [DOI: 10.1016/j.clineuro.2022.107472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/22/2022] [Accepted: 09/27/2022] [Indexed: 11/03/2022]
|
12
|
Cosentino S, Shih LC. Does essential tremor increase risk of cognitive impairment and dementia? Yes. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:195-231. [PMID: 35750363 DOI: 10.1016/bs.irn.2022.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Essential Tremor (ET), by definition, is a disorder of movement. Yet over the years, epidemiologic, clinical, pathologic, and neuroimaging studies have converged to reveal a cognitive side of ET. The cognitive symptoms in ET are heterogeneous and are likely to reflect heterogeneous underlying mechanisms. In this chapter, we review and synthesize a diverse set of studies from both population-based settings to cohorts with more detailed investigations into cognition to consider the various mechanisms by which cognitive symptoms may emerge in a subset of individuals with ET. As part of our analysis, we consider questions surrounding ET diagnosis and the possibility of comorbid disease as potential factors that, upon closer examination, appear to strengthen the argument in favor of ET as a risk factor for dementia. Importantly, we also consider the clinical relevance of cognitive impairment in ET. While ET is not universally characterized by significant cognitive deficits, the data from epidemiological, cognitive, neuroimaging, and postmortem neuropathologic studies converge to reveal an increased risk for cognitive impairment and dementia among individuals with ET. We conclude by offering directions for future research, and a neurocognitive framework with which to consider existing findings and to use in the design of novel studies dedicated to clarifying the basis, nature, and course of cognitive impairments in ET.
Collapse
Affiliation(s)
- Stephanie Cosentino
- Cognitive Neuroscience Division of the Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, United States; Department of Neurology, Columbia University Irving Medical Center, New York, United States.
| | - Ludy C Shih
- Department of Neurology, Parkinson's Disease and Movement Disorders Center, Boston Medical Center, Boston, Massachusetts, United States; Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, United States.
| |
Collapse
|
13
|
Lang EJ, Handforth A. Is the inferior olive central to essential tremor? Yes. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:133-165. [PMID: 35750361 DOI: 10.1016/bs.irn.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We consider the question whether the inferior olive (IO) is required for essential tremor (ET). Much evidence shows that the olivocerebellar system is the main system capable of generating the widespread synchronous oscillatory Purkinje cell (PC) complex spike (CS) activity across the cerebellar cortex that would be capable of generating the type of bursting cerebellar output from the deep cerebellar nuclei (DCN) that could underlie tremor. Normally, synchronous CS activity primarily reflects the effective electrical coupling of IO neurons by gap junctions, and traditionally, ET research has focused on the hypothesis of increased coupling of IO neurons as the cause of hypersynchronous CS activity underlying tremor. However, recent pathology studies of brains from humans with ET and evidence from mutant mice, particularly the hotfoot17 mouse, that largely replicate the pathology of ET, suggest that the abnormal innervation of multiple Purkinje cells (PCs) by climbing fibers (Cfs) is related to tremor. In addition, ET brains show partial PC loss and axon terminal sprouting by surviving PCs. This may provide another mechanism for tremor. It is proposed that in ET, these three mechanisms may promote tremor. They all involve hypersynchronous DCN activity and an intact IO, but the level at which excessive synchronization occurs may be at the IO level (from abnormal afferent activity to this nucleus), the PC level (via aberrant Cfs), or the DCN level (via terminal PC collateral innervation).
Collapse
|
14
|
Filip P, Burdová K, Valenta Z, Jech R, Kokošová V, Baláž M, Mangia S, Michaeli S, Bareš M, Vojtíšek L. Tremor associated with similar structural networks in Parkinson's disease and essential tremor. Parkinsonism Relat Disord 2021; 95:28-34. [PMID: 34979362 DOI: 10.1016/j.parkreldis.2021.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 12/01/2021] [Accepted: 12/20/2021] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Despite substantial clinical and pathophysiological differences, the characteristics of tremor in Parkinson's disease (PD) and essential tremor (ET) patients bear certain similarities. The presented study delineates tremor-related structural networks in these two disorders. METHODS 42 non-advanced PD patients (18 tremor-dominant, 24 without substantial tremor), 17 ET, and 45 healthy controls underwent high-angular resolution diffusion-weighted imaging acquisition to reconstruct their structural motor connectomes as a proxy of the anatomical interconnections between motor network regions, implementing state-of-the-art globally optimised probabilistic tractography. RESULTS When compared to healthy controls, ET patients exhibited higher structural connectivity in the cerebello-thalamo-cortical network. Interestingly, the comparison of tremor-dominant PD patients and PD patients without tremor yielded very similar results - higher structural connectivity in tremor-dominant PD sharing multiple nodes with the tremor network detected in ET, despite the generally lower structural connectivity between basal ganglia and frontal cortex in the whole PD group when compared to healthy controls. CONCLUSION The higher structural connectivity of the cerebello-thalamo-cortical network seems to be the dominant tremor driver in both PD and ET. While it appears to be the only tremor-related network in ET, its combination with large scale hypoconnectivity in the frontal cortico-subcortical network in PD may explain different clinical features of tremor in these two disorders.
Collapse
Affiliation(s)
- Pavel Filip
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic; Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, USA.
| | - Kristína Burdová
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Zdeněk Valenta
- Department of Statistical Modelling, Institute of Computer Science of the Czech Academy of Sciences, Prague, Czech Republic
| | - Robert Jech
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Viktória Kokošová
- Department of Neurology, Faculty of Medicine, Masaryk University and University Hospital Brno, Brno, Czech Republic
| | - Marek Baláž
- First Department of Neurology, Faculty of Medicine, Masaryk University and University Hospital of St. Anne, Brno, Czech Republic
| | - Silvia Mangia
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, USA
| | - Shalom Michaeli
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, USA
| | - Martin Bareš
- First Department of Neurology, Faculty of Medicine, Masaryk University and University Hospital of St. Anne, Brno, Czech Republic; Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Lubomír Vojtíšek
- Central European Institute of Technology (CEITEC), Masaryk University, Neuroscience Centre, Brno, Czech Republic
| |
Collapse
|
15
|
Fra̧czek TM, Ferleger BI, Brown TE, Thompson MC, Haddock AJ, Houston BC, Ojemann JG, Ko AL, Herron JA, Chizeck HJ. Closing the Loop With Cortical Sensing: The Development of Adaptive Deep Brain Stimulation for Essential Tremor Using the Activa PC+S. Front Neurosci 2021; 15:749705. [PMID: 34955714 PMCID: PMC8695120 DOI: 10.3389/fnins.2021.749705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/04/2021] [Indexed: 11/25/2022] Open
Abstract
Deep Brain Stimulation (DBS) is an important tool in the treatment of pharmacologically resistant neurological movement disorders such as essential tremor (ET) and Parkinson's disease (PD). However, the open-loop design of current systems may be holding back the true potential of invasive neuromodulation. In the last decade we have seen an explosion of activity in the use of feedback to "close the loop" on neuromodulation in the form of adaptive DBS (aDBS) systems that can respond to the patient's therapeutic needs. In this paper we summarize the accomplishments of a 5-year study at the University of Washington in the use of neural feedback from an electrocorticography strip placed over the sensorimotor cortex. We document our progress from an initial proof of hardware all the way to a fully implanted adaptive stimulation system that leverages machine-learning approaches to simplify the programming process. In certain cases, our systems out-performed current open-loop approaches in both power consumption and symptom suppression. Throughout this effort, we collaborated with neuroethicists to capture patient experiences and take them into account whilst developing ethical aDBS approaches. Based on our results we identify several key areas for future work. "Graded" aDBS will allow the system to smoothly tune the stimulation level to symptom severity, and frequent automatic calibration of the algorithm will allow aDBS to adapt to the time-varying dynamics of the disease without additional input from a clinician. Additionally, robust computational models of the pathophysiology of ET will allow stimulation to be optimized to the nuances of an individual patient's symptoms. We also outline the unique advantages of using cortical electrodes for control and the remaining hardware limitations that need to be overcome to facilitate further development in this field. Over the course of this study we have verified the potential of fully-implanted, cortically driven aDBS as a feasibly translatable treatment for pharmacologically resistant ET.
Collapse
Affiliation(s)
- Tomasz M. Fra̧czek
- Neuroscience Program, University of Washington, Seattle, WA, United States
| | - Benjamin I. Ferleger
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
| | - Timothy E. Brown
- Department of Philosophy, University of Washington, Seattle, WA, United States
| | - Margaret C. Thompson
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
| | - Andrew J. Haddock
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
| | - Brady C. Houston
- Neuroscience Program, University of Washington, Seattle, WA, United States
| | - Jeffrey G. Ojemann
- Department of Neurological Surgery, University of Washington, Seattle, WA, United States
| | - Andrew L. Ko
- Department of Neurological Surgery, University of Washington, Seattle, WA, United States
| | - Jeffrey A. Herron
- Department of Neurological Surgery, University of Washington, Seattle, WA, United States
| | - Howard J. Chizeck
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
| |
Collapse
|
16
|
Gionco JT, Hartstone WG, Martuscello RT, Kuo SH, Faust PL, Louis ED. Essential Tremor versus "ET-plus": A Detailed Postmortem Study of Cerebellar Pathology. CEREBELLUM (LONDON, ENGLAND) 2021; 20:904-912. [PMID: 33768479 PMCID: PMC8972074 DOI: 10.1007/s12311-021-01263-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/16/2021] [Indexed: 12/17/2022]
Abstract
Essential tremor (ET) is among the most prevalent movement disorders, and by some accounts, the most common form of cerebellar degeneration. Over the past 15 years, we have carefully documented a large number of postmortem changes within the cerebellum; these cerebellar changes differ significantly between ET and controls. A recent Consensus Classification of tremor proposed that ET patients with other neurological signs aside from action tremor (e.g., parkinsonism, ataxia, cognitive changes, dystonia) should be segregated off as "ET-plus". This diagnostic concept has raised considerable controversy and its validity is not yet established. Indeed, "ET-plus" has not been distinguished from ET based on differences in genetics, pathology or prognosis. Here we determine whether ET cases differ from "ET-plus" cases in underlying pathological changes in the postmortem brain. We examined postmortem brains from 50 ET cases (24 ET and 26 ET-plus), using a set of 14 quantitative metrics of cerebellar pathology determined by histologic and immunohistochemical methods. These metrics reflect changes across the Purkinje cell (PC) body (PC counts, empty baskets, heterotopias), PC dendrites (swellings), PC axon (torpedoes and associated axonal changes), basket cell axonal hypertrophy and climbing fiber-PC dendrite synaptic changes. ET and ET-plus were similar with respect to 13 of 14 cerebellar pathologic metrics (p > 0.05). Only one metric, the linear density of thickened PC axon profiles, differed between these groups (ET = 0.529 ± 0.397, ET-plus = 0.777 ± 0.477, p = 0.013), although after correcting for multiple comparisons, there were no differences. If ET-plus were indeed a different entity, then the underlying pathological basis should be distinct from that of ET. This study demonstrated there were no pathological differences in cerebellar cortex between ET versus ET-plus cases. These data do not support the notion that ET and ET-plus represent distinct clinical-pathological entities.
Collapse
Affiliation(s)
- John T Gionco
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX, 75390-9020, USA.
| |
Collapse
|
17
|
Louis ED, Faust PL. Essential Tremor Within the Broader Context of Other Forms of Cerebellar Degeneration. THE CEREBELLUM 2021; 19:879-896. [PMID: 32666285 DOI: 10.1007/s12311-020-01160-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Essential tremor (ET) has recently been reconceptualized by many as a degenerative disease of the cerebellum. Until now, though, there has been no attempt to frame it within the context of these diseases. Here, we compare the clinical and postmortem features of ET with other cerebellar degenerations, thereby placing it within the broader context of these diseases. Action tremor is the hallmark feature of ET. Although often underreported in the spinocerebellar ataxias (SCAs), action tremors occur, and it is noteworthy that in SCA12 and 15, they are highly prevalent, often severe, and can be the earliest disease manifestation, resulting in an initial diagnosis of ET in many cases. Intention tremor, sometimes referred to as "cerebellar tremor," is a common feature of ET and many SCAs. Other features of cerebellar dysfunction, gait ataxia and eye motion abnormalities, are seen to a mild degree in ET and more markedly in SCAs. Several SCAs (e.g., SCA5, 6, 14, and 15), like ET, follow a milder and more protracted disease course. In ET, numerous postmortem changes have been localized to the cerebellum and are largely confined to the cerebellar cortex, preserving the cerebellar nuclei. Purkinje cell loss is modest. Similarly, in SCA3, 12, and 15, Purkinje cell loss is limited, and in SCA12 and 15, there is preservation of cerebellar nuclei and relative sparing of other central nervous system regions. Both clinically and pathologically, there are numerous similarities and intersection points between ET and other disorders of cerebellar degeneration.
Collapse
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
| |
Collapse
|
18
|
Wu YC, Louis ED, Gionco J, Pan MK, Faust PL, Kuo SH. Increased Climbing Fiber Lateral Crossings on Purkinje Cell Dendrites in the Cerebellar Hemisphere in Essential Tremor. Mov Disord 2021; 36:1440-1445. [PMID: 33497495 PMCID: PMC8217183 DOI: 10.1002/mds.28502] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 12/21/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Climbing fibers (CFs) innervate Purkinje cells (PCs) with 1:1 relationship to ensure proper cerebellar function. Although CFs abnormally extend into the parallel fiber domain of PC dendrites in essential tremor (ET), the architecture of CFs in relation to PCs has yet to be investigated in detail. OBJECTIVE The aim of this work was to study the architecture of CFs in relation to PCs in ET. METHODS The number of PC somas and PC dendrites that a single CF crossed was quantified in the postmortem cerebellum of 15 ET cases and 15 control cases. RESULTS In ET, CFs crossed a greater number of PC somas and PC dendrites than in control cases, raising the possibility that there is abnormal CF wiring onto the PCs. Interestingly, the increase in CF-PC crossings positively correlated with tremor severity. CONCLUSIONS Patients with ET have increased CF crossings on PC dendrites. This abnormal architectural arrangement may contribute to synchronous brain activity and tremor. © 2021 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Yueh-Chi Wu
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
| | - Elan D. Louis
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, Texas, USA
| | - John Gionco
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Ming-Kai Pan
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Phyllis L. Faust
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- InitiatIve for Columbia Ataxia and Tremor, Columbia University, New York, New York, USA
| |
Collapse
|
19
|
Billeri L, Naro A. A narrative review on non-invasive stimulation of the cerebellum in neurological diseases. Neurol Sci 2021; 42:2191-2209. [PMID: 33759055 DOI: 10.1007/s10072-021-05187-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 03/15/2021] [Indexed: 12/26/2022]
Abstract
IMPORTANCE The cerebellum plays an important role in motor, cognitive, and affective functions owing to its dense interconnections with basal ganglia and cerebral cortex. This review aimed at summarizing the non-invasive cerebellar stimulation (NICS) approaches used to modulate cerebellar output and treat cerebellar dysfunction in the motor domain. OBSERVATION The utility of NICS in the treatment of cerebellar and non-cerebellar neurological diseases (including Parkinson's disease, dementia, cerebellar ataxia, and stroke) is discussed. NICS induces meaningful clinical effects from repeated sessions alone in both cerebellar and non-cerebellar diseases. However, there are no conclusive data on this issue and several concerns need to be still addressed before NICS could be considered a valuable, standard therapeutic tool. CONCLUSIONS AND RELEVANCE Even though some challenges must be overcome to adopt NICS in a wider clinical setting, this tool might become a useful strategy to help patients with lesions in the cerebellum and cerebral areas that are connected with the cerebellum whether one could enhance cerebellar activity with the intention of facilitating the cerebellum and the entire, related network, rather than attempting to facilitate a partially damaged cortical region or inhibiting the homologs' contralateral area. The different outcome of each approach would depend on the residual functional reserve of the cerebellum, which is confirmed as a critical element to be probed preliminary in order to define the best patient-tailored NICS.
Collapse
Affiliation(s)
- Luana Billeri
- IRCCS Centro Neurolesi Bonino Pulejo, via Palermo, SS113, Ctr. Casazza, 98124, Messina, Italy
| | - Antonino Naro
- IRCCS Centro Neurolesi Bonino Pulejo, via Palermo, SS113, Ctr. Casazza, 98124, Messina, Italy.
| |
Collapse
|
20
|
Horisawa S, Kohara K, Nonaka T, Mochizuki T, Kawamata T, Taira T. Case Report: Deep Cerebellar Stimulation for Tremor and Dystonia. Front Neurol 2021; 12:642904. [PMID: 33746894 PMCID: PMC7973230 DOI: 10.3389/fneur.2021.642904] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/12/2021] [Indexed: 12/20/2022] Open
Abstract
Background: The cerebellum plays an important role in the pathogenesis and pathophysiology of movement disorders, including tremor and dystonia. To date, there have been few reports on deep cerebellar stimulation. Case Report: The patient was a 35-year-old previously healthy man with no history of movement disorders. He developed a tremor and stiffness in his left hand at the age of 27 years, which was diagnosed as a dystonic tremor. We performed right thalamotomy, which resulted in a complete resolution of the tremor; however, the dystonia persisted. Subsequently, the patient developed left foot dystonia with inversion and a newly developed tremor in the right hand and foot. The patient underwent left ventralis intermedius (VIM) deep brain stimulation (VIM-DBS) and left pallidothalamic tract DBS (PTT-DBS). Left VIM-DBS completely resolved the right hand and foot tremor, and PTT-DBS significantly improved the left hand and foot dystonia. Three months postoperatively, the patient developed an infection and wound disruption at the surgical site. We performed palliative surgery for deep cerebellar stimulation via the posterior cranial region, which was not infected. The surgery was performed under general anesthesia with the patient lying in the prone position. Eight contact DBS electrodes were used. The placement of electrodes extended from the superior cerebellar peduncle to the dentate nucleus. Both the right hand and foot tremor improved with right cerebellar stimulation. Further, both the left hand and foot dystonia improved with left cerebellar stimulation. Right and left cerebellar stimulation led to no improvement in the left hand and foot dystonia and right hand and foot tremor, respectively. Stimulation-induced complications observed in the patient included dizziness, dysphagia, and dysarthria. After the surgery, the patient developed hypersalivation and hyperhidrosis in the left side of the body, both of which did not improve with adjustments of stimulation parameters. At the 6-month follow-up, the tremor and dystonia had almost completely resolved. Conclusion: Deep cerebellar stimulation deserves consideration as a potential treatment for tremor and dystonia.
Collapse
Affiliation(s)
- Shiro Horisawa
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| | - Kotaro Kohara
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| | - Taku Nonaka
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| | - Tatsuki Mochizuki
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| | - Takakazu Kawamata
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| | - Takaomi Taira
- Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan
| |
Collapse
|
21
|
Hartstone WG, Brown MH, Kelly GC, Tate WJ, Kuo SH, Dwork AJ, Louis ED, Faust PL. Dentate Nucleus Neuronal Density: A Postmortem Study of Essential Tremor Versus Control Brains. Mov Disord 2020; 36:995-999. [PMID: 33258511 DOI: 10.1002/mds.28402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 10/26/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Essential tremor involves the cerebellum, yet quantitative analysis of dentate nucleus neurons has not been conducted. OBJECTIVES To quantitatively compare neuronal density or neuronal number in the dentate nucleus of essential tremor versus age-matched controls. METHODS Using a 7-μm thick Luxol fast blue hematoxylin and eosin-stained paraffin section, dentate nucleus neuronal density (neurons/mm2 ) was determined in 25 essential tremor cases and 25 controls. We also applied a stereological approach in a subset of four essential tremor cases and four controls to estimate total dentate nucleus neuronal number. RESULTS Dentate nucleus neuronal density did not differ between essential tremor cases and controls (P = 0.44). Total dentate nucleus neuronal number correlated with neuronal density (P = 0.007) and did not differ between essential tremor cases and controls (P = 0.95). CONCLUSIONS Neuronal loss, observed in the Purkinje cell population in essential tremor, did not seem to similarly involve the dentate nucleus in essential tremor. © 2020 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Mark H Brown
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Geoffrey C Kelly
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - William J Tate
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Andrew J Dwork
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA.,Department of Psychiatry, Columbia University, New York, New York, USA.,Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute New York, New York, New York, USA
| | - Elan D Louis
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, Texas, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
22
|
Handforth A, Lang EJ. Increased Purkinje Cell Complex Spike and Deep Cerebellar Nucleus Synchrony as a Potential Basis for Syndromic Essential Tremor. A Review and Synthesis of the Literature. THE CEREBELLUM 2020; 20:266-281. [PMID: 33048308 DOI: 10.1007/s12311-020-01197-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 12/19/2022]
Abstract
We review advances in understanding Purkinje cell (PC) complex spike (CS) physiology that suggest increased CS synchrony underlies syndromic essential tremor (ET). We searched PubMed for papers describing factors that affect CS synchrony or cerebellar circuits potentially related to tremor. Inferior olivary (IO) neurons are electrically coupled, with the degree of coupling controlled by excitatory and GABAergic inputs. Clusters of coupled IO neurons synchronize CSs within parasagittal bands via climbing fibers (Cfs). When motor cortex is stimulated in rats at varying frequencies, whisker movement occurs at ~10 Hz, correlated with synchronous CSs, indicating that the IO/CS oscillatory rhythm gates movement frequency. Intra-IO injection of the GABAA receptor antagonist picrotoxin increases CS synchrony, increases whisker movement amplitude, and induces tremor. Harmaline and 5-HT2a receptor activation also increase IO coupling and CS synchrony and induce tremor. The hotfoot17 mouse displays features found in ET brains, including cerebellar GluRδ2 deficiency and abnormal PC Cf innervation, with IO- and PC-dependent cerebellar oscillations and tremor likely due to enhanced CS synchrony. Heightened coupling within the IO oscillator leads, through its dynamic control of CS synchrony, to increased movement amplitude and, when sufficiently intense, action tremor. Increased CS synchrony secondary to aberrant Cf innervation of multiple PCs likely also underlies hotfoot17 tremor. Deep cerebellar nucleus (DCN) hypersynchrony may occur secondary to increased CS synchrony but might also occur from PC axonal terminal sprouting during partial PC loss. Through these combined mechanisms, increased CS/DCN synchrony may plausibly underlie syndromic ET.
Collapse
Affiliation(s)
- Adrian Handforth
- Neurology Service, Veterans Affairs Greater Los Angeles Healthcare System, 11301 Wilshire Blvd., Los Angeles, CA, 90073, USA.
| | - Eric J Lang
- Department of Neuroscience and Physiology, New York University, School of Medicine, New York, NY, USA
| |
Collapse
|
23
|
Louis ED, Faust PL. Essential tremor: the most common form of cerebellar degeneration? CEREBELLUM & ATAXIAS 2020; 7:12. [PMID: 32922824 PMCID: PMC7427947 DOI: 10.1186/s40673-020-00121-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
Background The degenerative cerebellar ataxias comprise a large and heterogeneous group of neurological diseases whose hallmark clinical feature is ataxia, and which are accompanied, to variable degrees, by other features that are attributable to cerebellar dysfunction. Essential tremor (ET) is an exceptionally common neurological disease whose primary motor feature is action tremor, although patients often manifest intention tremor, mild gait ataxia and several other features of cerebellar dysfunction. Main Body In this paper, we review the abundant evidence derived from clinical, neuroimaging and postmortem studies, linking ET to cerebellar dysfunction. Furthermore, we review the combination of clinical, natural history and postmortem features suggesting that ET is neurodegenerative. We then compare the prevalence of ET (400 – 900 cases per 100,000) to that of the other cerebellar degenerations (ranging from <0.5 – 9 cases per 100,000, and in composite likely to be on the order of 20 cases per 100,000) and conclude that ET is 20 to 45 times more prevalent than all other forms of cerebellar degeneration combined. Conclusion Given the data we present, it is logical to conclude that ET is, by far, the most common form of cerebellar degeneration.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology and Therapeutics, University of Texas Southwestern, Dallas, TX USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY USA
| |
Collapse
|
24
|
The Problem of Questionable Dystonia in the Diagnosis of 'Essential Tremor-Plus'. Tremor Other Hyperkinet Mov (N Y) 2020; 10:27. [PMID: 32864186 PMCID: PMC7427675 DOI: 10.5334/tohm.539] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In a recent consensus statement on tremor, the task force of the International Parkinson and Movement Disorder Society proposed a new term, ‘essential tremor-plus (ET-plus)’ which includes patients with the characteristics of essential tremor (ET) and additional soft neurological signs of uncertain significance such as questionable dystonic posturing. The clinical interpretation of questionable dystonia has been left to the investigator. The consensus statement also stated that the ET-plus syndrome does not include other clearly defined syndromes like dystonic tremor. However, the boundary between questionable dystonia and definite dystonia is not distinct leading to diagnostic uncertainty in a clinical setting. A similar case may be classified as ET-plus by one observer and dystonic tremor by another. Following the new definition, many studies have reclassified their ET cohort, and they have highlighted the problem of defining questionable dystonia in the diagnosis of ET plus. ET-plus is likely to be a mixture of patients that actually have dystonia and those that don’t, and clinically all we can do is to be suspicious that there might be dystonia. For example, it is not clear whether we should consider spooning and index finger pointing as a sign of questionable or definite dystonia. There are major research and possible therapeutic implications of questionable dystonia in the diagnosis of ET-plus. The concept of ET-plus is extremely difficult to implement without definite guidelines. The resolution will need a biomarker such as physiology or imaging.
Collapse
|
25
|
Auditory and Olfactory Deficits in Essential Tremor - Review of the Current Evidence. Tremor Other Hyperkinet Mov (N Y) 2020; 10:3. [PMID: 32775017 PMCID: PMC7394198 DOI: 10.5334/tohm.57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Essential tremor (ET) is the most common adult movement disorder, characterized by several motor and increasingly well recognized non-motor symptoms. Sensory deficits, such as hearing impairment and olfactory dysfunction, are amongst them. This review analyzes the available evidence of these sensory deficits and their possible mechanistic basis in patients with ET. Method: A PubMed literature search on the topic was performed in the May 2019 database. Results: Nineteen articles on hearing impairment and olfactory dysfunction in ET patients were identified. The prevalence of hearing impairment is higher in ET patients than healthy controls or Parkinson disease. Cochlear pathologies are suggested as the underlying cause, but there is still a lack of information about retrocochlear pathologies and central auditory processing. Reports on olfactory dysfunction have conflicting results. The presence of mild olfactory dysfunction in ET was suggested. Conflicting results may be due to the lack of consideration of the disease’s heterogeneity, but according to recent data, most studies do not find prominent evidence of olfactory loss in ET. Conclusion: Although there is increasing interest in studies on non-motor symptoms in ET, there are few studies on sensory deficits, which are of particularly high prevalence. More studies are needed on to investigate the basis of non-motor symptoms, including sensory deficits.
Collapse
|
26
|
Sengul Y, Bal N, Louis ED. Evidence of central involvement in essential tremor: a detailed study of auditory pathway physiology. J Neural Transm (Vienna) 2020; 127:1153-1159. [PMID: 32507996 DOI: 10.1007/s00702-020-02215-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 05/28/2020] [Indexed: 10/24/2022]
Abstract
Essential tremor (ET) is a common tremor disorder that is likely neurodegenerative. The pathophysiology of ET involves the cerebellum and its connections in the brainstem and thalamus. Hearing dysfunction has been shown to be a non-motor finding in ET patients. A limited number of studies have suggested that cochlear pathology is the cause, but studies have not evaluated the integrity of the primary auditory pathway in ET. The main aim of this study is to investigate the integrity of the auditory pathway via auditory brainstem response (ABR) and auditory middle latency response (AMLR), thereby allowing us to evaluate the auditory pathway from the 8th cranial nerve to the cerebral cortex. Sixteen ET patients and sixteen age- and gender-matched controls (64 ears) were evaluated. In the ABR study, we detected prolongation of wave V peak latencies (ms) in ET (p = 0.02). In the AMLR study, P0 (p = 0.03), Pa (p = 0.008), Na (p = 0.03), and Nb (p = 0.01) waves differed between the two groups. Eleven ET patients and four control subjects had abnormal electrophysiological findings (ABR or AMLR or both) (68.8% vs. 25%, p = 0.01). Tremor duration was greater in ET patients with abnormal electrophysiological findings (p = 0.01). Finally, we observed prolongation of latencies after the ABR III wave, indicating that abnormalities exist within the superior olivary complex. For the first time, our research provides evidence that ET-related pathology is present at the subcortical and cortical levels of the auditory pathway.
Collapse
Affiliation(s)
- Yildizhan Sengul
- Department of Neurology, Faculty of Medicine, Bezmialem Foundation University, Fatih, Istanbul, Turkey. .,Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA.
| | - Nilufer Bal
- Department of Audiology, Faculty of Medical Sciences, Bezmialem Foundation University, Fatih, Istanbul, Turkey
| | - Elan D Louis
- Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA.,Center for Neuroepidemiology and Clinical Neurological Research, 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
| |
Collapse
|
27
|
Samuelsson JG, Sundaram P, Khan S, Sereno MI, Hämäläinen MS. Detectability of cerebellar activity with magnetoencephalography and electroencephalography. Hum Brain Mapp 2020; 41:2357-2372. [PMID: 32115870 PMCID: PMC7244390 DOI: 10.1002/hbm.24951] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/15/2019] [Accepted: 02/01/2020] [Indexed: 12/31/2022] Open
Abstract
Electrophysiological signals from the cerebellum have traditionally been viewed as inaccessible to magnetoencephalography (MEG) and electroencephalography (EEG). Here, we challenge this position by investigating the ability of MEG and EEG to detect cerebellar activity using a model that employs a high‐resolution tessellation of the cerebellar cortex. The tessellation was constructed from repetitive high‐field (9.4T) structural magnetic resonance imaging (MRI) of an ex vivo human cerebellum. A boundary‐element forward model was then used to simulate the M/EEG signals resulting from neural activity in the cerebellar cortex. Despite significant signal cancelation due to the highly convoluted cerebellar cortex, we found that the cerebellar signal was on average only 30–60% weaker than the cortical signal. We also made detailed M/EEG sensitivity maps and found that MEG and EEG have highly complementary sensitivity distributions over the cerebellar cortex. Based on previous fMRI studies combined with our M/EEG sensitivity maps, we discuss experimental paradigms that are likely to offer high M/EEG sensitivity to cerebellar activity. Taken together, these results show that cerebellar activity should be clearly detectable by current M/EEG systems with an appropriate experimental setup.
Collapse
Affiliation(s)
- John G Samuelsson
- Harvard-MIT Division of Health Sciences and Technology (HST), Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Padmavathi Sundaram
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Sheraz Khan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Martin I Sereno
- Department of Psychology and Neuroimaging Center, San Diego State University, San Diego, California, USA.,Experimental Psychology, University College London, London, UK
| | - Matti S Hämäläinen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
28
|
Awad A, Blomstedt P, Westling G, Eriksson J. Deep brain stimulation in the caudal zona incerta modulates the sensorimotor cerebello-cerebral circuit in essential tremor. Neuroimage 2019; 209:116511. [PMID: 31901420 DOI: 10.1016/j.neuroimage.2019.116511] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/09/2019] [Accepted: 12/30/2019] [Indexed: 01/25/2023] Open
Abstract
Essential tremor is effectively treated with deep brain stimulation (DBS), but the neural mechanisms underlying the treatment effect are poorly understood. Essential tremor is driven by a dysfunctional cerebello-thalamo-cerebral circuit resulting in pathological tremor oscillations. DBS is hypothesised to interfere with these oscillations at the stimulated target level, but it is unknown whether the stimulation modulates the activity of the cerebello-thalamo-cerebral circuit during different task states (with and without tremor) in awake essential tremor patients. To address this issue, we used functional MRI in 16 essential tremor patients chronically implanted with DBS in the caudal zona incerta. During scanning, the patients performed unilateral tremor-inducing postural holding and pointing tasks as well as rest, with contralateral stimulation turned On and Off. We show that DBS exerts both task-dependent as well as task-independent modulation of the sensorimotor cerebello-cerebral regions (p ≤ 0.05, FWE cluster-corrected for multiple comparisons). Task-dependent modulation (DBS × task interaction) resulted in two patterns of stimulation effects. Firstly, activity decreases (blood oxygen level-dependent signal) during tremor-inducing postural holding in the primary sensorimotor cortex and cerebellar lobule VIII, and activity increases in the supplementary motor area and cerebellar lobule V during rest (p ≤ 0.05, post hoc two-tailed t-test). These effects represent differences at the effector level and may reflect DBS-induced tremor reduction since the primary sensorimotor cortex, cerebellum and supplementary motor area exhibit less motor task-activity as compared to the resting condition during On stimulation. Secondly, task-independent modulation (main effect of DBS) was observed as activity increase in the lateral premotor cortex during all motor tasks, and also during rest (p ≤ 0.05, post hoc two-tailed t-test). This task-independent effect may mediate the therapeutic effects of DBS through the facilitation of the premotor control over the sensorimotor circuit, making it less susceptible to tremor entrainment. Our findings support the notion that DBS in essential tremor is modulating the sensorimotor cerebello-cerebral circuit, distant to the stimulated target, and illustrate the complexity of stimulation mechanisms by demonstrating task-dependent as well as task-independent actions in cerebello-cerebral regions.
Collapse
Affiliation(s)
- Amar Awad
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Sweden; Department of Integrative Medical Biology, Physiology Section, Umeå University, Sweden.
| | - Patric Blomstedt
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Sweden
| | - Göran Westling
- Department of Integrative Medical Biology, Physiology Section, Umeå University, Sweden
| | - Johan Eriksson
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Sweden; Department of Integrative Medical Biology, Physiology Section, Umeå University, Sweden
| |
Collapse
|
29
|
Paul JL, Dashtipour K, Chen Z, Wang C. DNA methylome study of human cerebellar tissues identified genes and pathways possibly involved in essential tremor. PRECISION CLINICAL MEDICINE 2019; 2:221-234. [PMID: 31886034 PMCID: PMC6927097 DOI: 10.1093/pcmedi/pbz028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/30/2019] [Accepted: 12/01/2019] [Indexed: 01/13/2023] Open
Abstract
Background Essential tremor (ET) is a neurological syndrome of unknown origin with poorly understood etiology and pathogenesis. It is suggested that the cerebellum and its tracts may be involved in the pathophysiology of ET. DNA methylome interrogation of cerebellar tissue may help shine some light on the understanding of the mechanism of the development of ET. Our study used postmortem human cerebellum tissue samples collected from 12 ET patients and 11 matched non-ET controls for DNA methylome study to identify differentially methylated genes in ET. Results Using Nugen’s Ovation reduced representation bisulfite sequencing (RRBS), we identified 753 genes encompassing 938 CpG sites with significant differences in DNA methylation between the ET and the control group. Identified genes were further analyzed with Ingenuity Pathway Analysis (IPA) by which we identified certain significant pathways, upstream regulators, diseases and functions, and networks associated with ET. Conclusions Our study provides evidence that there are significant differences in DNA methylation patterns between the ET and control samples, suggesting that the methylation alteration of certain genes in the cerebellum may be associated with ET pathogenesis. The identified genes allude to the GABAergic hypothesis which supports the notation that ET is a neurodegenerative disease, particularly involving the cerebellum.
Collapse
Affiliation(s)
- Jennifer L Paul
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Khashayar Dashtipour
- Division of Movement Disorders, Department of Neurology, Loma Linda University Medical Center, Loma Linda, CA 92350, USA
| | - Zhong Chen
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Charles Wang
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.,Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| |
Collapse
|
30
|
Lenka A, Louis ED. Revisiting the Clinical Phenomenology of "Cerebellar Tremor": Beyond the Intention Tremor. THE CEREBELLUM 2019; 18:565-574. [PMID: 30565088 DOI: 10.1007/s12311-018-0994-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tremor is an involuntary, rhythmic, oscillatory movement of a body part. It is a central feature of a range of diseases resulting from pathological changes in the cerebellum. Interestingly, in modern times, the terms "cerebellar tremor" and "intention tremor" are often used synonymously and interchangeably. However, "cerebellar tremor" (i.e., tremors of cerebellar origin) do not always present exclusively as intention tremor. In this article, we comprehensively revisit the clinical phenomenology of tremors observed in various diseases that are based in the cerebellum. By this, we mean diseases for which the cerebellum and its various connections are often seen as playing a central and defining role. These include spinocerebellar ataxias, essential tremor, orthostatic tremor, dystonia, acute cerebellitis, cerebellar tumors, paraneoplastic cerebellar degeneration, and cerebellar strokes. The theme of this article is to highlight, through published data available in the current literature, that the clinical phenomenology of tremor of cerebellar origin is heterogeneous, and it extends beyond that of intention tremor to include postural tremors, kinetic tremor, rest tremor, and orthostatic tremor. This heterogeneity is consistent with the seminal work of Gordon Holmes, in which he described a variety of tremors aside from intention tremor in the setting of cerebellar lesions. In the end, it would seem that the notion that intention tremor is the sole signature of cerebellar lesions is an over-simplification and is not correct. Future studies are warranted to identify and further characterize the heterogeneity of tremors arising from the various cerebellar etiologies.
Collapse
Affiliation(s)
- Abhishek Lenka
- Department of Neurology, MedStar Georgetown University Hospital, Washington, DC, USA
| | - 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. .,Department of Neurology, Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, 15 York Street, PO Box 208018, New Haven, CT, 06520-8018, USA.
| |
Collapse
|
31
|
Lai RY, Tomishon D, Figueroa KP, Pulst SM, Perlman S, Wilmot G, Gomez CM, Schmahmann JD, Paulson H, Shakkottai VG, Ying SH, Zesiewicz T, Bushara K, Geschwind M, Xia G, Subramony SH, Ashizawa T, Kuo SH. Tremor in the Degenerative Cerebellum: Towards the Understanding of Brain Circuitry for Tremor. THE CEREBELLUM 2019; 18:519-526. [PMID: 30830673 DOI: 10.1007/s12311-019-01016-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebellar degenerative pathology has been identified in tremor patients; however, how the degenerative pathology could contribute to tremor remains unclear. If the cerebellar degenerative pathology can directly drive tremor, one would hypothesize that tremor is likely to occur in the diseases of cerebellar ataxia and follows the disease progression in such disorders. To further test this hypothesis, we studied the occurrence of tremor in different disease stages of classical cerebellar degenerative disorders: spinocerebellar ataxias (SCAs). We further separately analyzed postural tremor and rest tremor, two forms of tremor that both involve the cerebellum. We also explored tremor in different subtypes of SCAs. We found that 18.1% of SCA patients have tremor. Interestingly, SCA patients with tremor have worse ataxia than those without tremor. When stratifying patients into mild, moderate, and severe disease stages according to the severity of ataxia, moderate and severe SCA patients more commonly have tremor than those with mild ataxia, the effect most prominently observed in postural tremor of SCA3 and SCA6 patients. Finally, tremor can independently contribute to worse functional status in SCA2 patients, even after adjusting for ataxia severity. Tremor is more likely to occur in the severe stage of cerebellar degeneration when compared to mild stages. Our results partially support the cerebellar degenerative model of tremor.
Collapse
Affiliation(s)
- Ruo-Yah Lai
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Darya Tomishon
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Karla P Figueroa
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Susan Perlman
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - George Wilmot
- Department of Neurology, Emory University, Atlanta, GA, USA
| | | | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Henry Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | | | - Sarah H Ying
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Theresa Zesiewicz
- Department of Neurology, University of South Florida, Tampa, FL, USA
| | - Khalaf Bushara
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA
| | - Michael Geschwind
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Guangbin Xia
- Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - S H Subramony
- Department of Neurology and McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | | | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| |
Collapse
|
32
|
Kuo SH, Louis ED, Faust PL, Handforth A, Chang SY, Avlar B, Lang EJ, Pan MK, Miterko LN, Brown AM, Sillitoe RV, Anderson CJ, Pulst SM, Gallagher MJ, Lyman KA, Chetkovich DM, Clark LN, Tio M, Tan EK, Elble RJ. Current Opinions and Consensus for Studying Tremor in Animal Models. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1036-1063. [PMID: 31124049 PMCID: PMC6872927 DOI: 10.1007/s12311-019-01037-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tremor is the most common movement disorder; however, we are just beginning to understand the brain circuitry that generates tremor. Various neuroimaging, neuropathological, and physiological studies in human tremor disorders have been performed to further our knowledge of tremor. But, the causal relationship between these observations and tremor is usually difficult to establish and detailed mechanisms are not sufficiently studied. To overcome these obstacles, animal models can provide an important means to look into human tremor disorders. In this manuscript, we will discuss the use of different species of animals (mice, rats, fruit flies, pigs, and monkeys) to model human tremor disorders. Several ways to manipulate the brain circuitry and physiology in these animal models (pharmacology, genetics, and lesioning) will also be discussed. Finally, we will discuss how these animal models can help us to gain knowledge of the pathophysiology of human tremor disorders, which could serve as a platform towards developing novel therapies for tremor.
Collapse
Affiliation(s)
- Sheng-Han Kuo
- Department of Neurology, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA.
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 800 Howard Avenue, Ste Lower Level, New Haven, CT, 06519, USA.
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA.
- Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Adrian Handforth
- Neurology Service, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Su-Youne Chang
- Department of Neurologic Surgery and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Billur Avlar
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Eric J Lang
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Ming-Kai Pan
- Department of Medical Research and Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lauren N Miterko
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
| | - Amanda M Brown
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Collin J Anderson
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | | | - Kyle A Lyman
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Lorraine N Clark
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Murni Tio
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Rodger J Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
| |
Collapse
|
33
|
Malik AR, Willnow TE. Excitatory Amino Acid Transporters in Physiology and Disorders of the Central Nervous System. Int J Mol Sci 2019; 20:ijms20225671. [PMID: 31726793 PMCID: PMC6888459 DOI: 10.3390/ijms20225671] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Excitatory amino acid transporters (EAATs) encompass a class of five transporters with distinct expression in neurons and glia of the central nervous system (CNS). EAATs are mainly recognized for their role in uptake of the amino acid glutamate, the major excitatory neurotransmitter. EAATs-mediated clearance of glutamate released by neurons is vital to maintain proper glutamatergic signalling and to prevent toxic accumulation of this amino acid in the extracellular space. In addition, some EAATs also act as chloride channels or mediate the uptake of cysteine, required to produce the reactive oxygen speciesscavenger glutathione. Given their central role in glutamate homeostasis in the brain, as well as their additional activities, it comes as no surprise that EAAT dysfunctions have been implicated in numerous acute or chronic diseases of the CNS, including ischemic stroke and epilepsy, cerebellar ataxias, amyotrophic lateral sclerosis, Alzheimer’s disease and Huntington’s disease. Here we review the studies in cellular and animal models, as well as in humans that highlight the roles of EAATs in the pathogenesis of these devastating disorders. We also discuss the mechanisms regulating EAATs expression and intracellular trafficking and new exciting possibilities to modulate EAATs and to provide neuroprotection in course of pathologies affecting the CNS.
Collapse
Affiliation(s)
- Anna R. Malik
- Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
- Correspondence:
| | | |
Collapse
|
34
|
Martuscello RT, Kerridge CA, Chatterjee D, Hartstone WG, Kuo SH, Sims PA, Louis ED, Faust PL. Gene expression analysis of the cerebellar cortex in essential tremor. Neurosci Lett 2019; 721:134540. [PMID: 31707044 DOI: 10.1016/j.neulet.2019.134540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/28/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023]
Abstract
Essential tremor (ET) is one of the most common neurological diseases, with a central feature of an 8-12 Hz kinetic tremor. While previous postmortem studies have identified a cluster of morphological changes in the ET cerebellum centered in/around the Purkinje cell (PC) population, including a loss of PCs in some studies, the underlying molecular mechanisms for these changes are not clear. As genomic studies of ET patients have yet to identify major genetic contributors and animal models that fully recapitulate the human disease do not yet exist, the study of human tissue is currently the most applicable method to gain a mechanistic insight into ET disease pathogenesis. To begin exploration of an underlying molecular source of ET disease pathogenesis, we have performed the first transcriptomic analysis by direct sequencing of RNA from frozen cerebellar cortex tissue in 33 ET patients compared to 21 normal controls. Principal component analysis showed a heterogenous distribution of the expression data in ET patients that only partially overlapped with control patients. Differential expression analysis identified 231 differentially expressed gene transcripts ('top gene hits'), a subset of which has defined expression profiles in the cerebellum across neuronal and glial cell types but a largely unknown relationship to cerebellar function and/or ET pathogenesis. Gene set enrichment analysis (GSEA) identified dysregulated pathways of interest and stratified dysregulation among ET cases. By GSEA and mining curated databases, we compiled major categories of dysregulated processes and clustered string networks of known interacting proteins. Here we demonstrate that these 'top gene hits' contribute to regulation of four main biological processes, which are 1) axon guidance, 2) microtubule motor activity, 3) endoplasmic reticulum (ER) to Golgi transport and 4) calcium signaling/synaptic transmission. The results of our transcriptomic analysis suggest there is a range of different processes involved among ET cases, and draws attention to a particular set of genes and regulatory pathways that provide an initial platform to further explore the underlying biology of ET.
Collapse
Affiliation(s)
- Regina T Martuscello
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Chloë A Kerridge
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Debotri Chatterjee
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Whitney G Hartstone
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| | - Sheng-Han Kuo
- College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 W 168th Street, BB302, New York, NY, USA.
| | - Peter A Sims
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 W 168th Street, BB302, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, 3960 Broadway, RM208, New York, NY, USA; Sulzberger Columbia Genome Center, Columbia University Medical Center, 1150 St. Nicholas Ave., New York, NY, USA; Department of Biochemistry & Molecular Biophysics, Columbia University Medical Center, 701 W 168th Street, New York, NY, USA.
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 15 York Street, New Haven, CT, USA; Department of Chronic Disease Epidemiology, Yale School of Public Health, 15 York Street, Yale University, New Haven, CT, USA; Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, 15 York Street, New Haven, CT, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, P&S 15-405, New York, NY, USA; College of Physicians and Surgeons, Columbia University Medical Center and the New York Presbyterian Hospital, 630 W 168th Street, New York, NY, USA.
| |
Collapse
|
35
|
Kovács A, Farkas Z, Kelemen A, Juhos V, Szűcs A, Kamondi A. Lamotrigine Induces Tremor among Epilepsy Patients Probably via Cerebellar Pathways. TOHOKU J EXP MED 2019; 248:273-284. [PMID: 31447473 DOI: 10.1620/tjem.248.273] [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] [Indexed: 11/18/2022]
Abstract
Lamotrigine, a frequently used antiepileptic drug, inhibits voltage-gated sodium-channels. By suppressing the release of glutamate and aspartate, lamotrigine acts as a membrane stabilizer, and it is also effective in bipolar disorder and migraine. However, lamotrigine is known to induce tremor among 4-10% of patients. We examined the lamotrigine-induced tremor in 28 epilepsy patients (age: 38.06 ± 13.56 years; 24 females and 4 males) receiving lamotrigine monotherapy and compared the data to 30 age- and sex-matched controls (age: 33.06 ± 10.71 years; 25 females and 5 males). Tremor was visually assessed by clinical tremor rating scales. Quantitative characteristics (intensity, center frequency and frequency dispersion) which are regularly used to differentiate various tremor syndromes were measured by validated, sensitive biaxial accelerometry in resting, postural and intentional positions. Regularity of repetitive finger and hand movements and reaction time were also determined. Data were statistically analyzed. Clinical tremor rating scales detected pathological tremor in three patients (10%), while accelerometry revealed tremor in seven patients (25%). Center frequency of patients with pathological tremor was similar to controls, but the frequency dispersion was significantly lower and tremor intensity was significantly higher in both postural and intentional positions. Rhythmic movements and reaction time were normal. Our results show that objective measurements detect pathological intention tremor in 25% of epilepsy patients receiving lamotrigine monotherapy. Quantitative characteristics suggest the involvement of the cerebellum in the pathomechanism of lamotrigine-induced tremor. Determining the parameters of drug-induced tremor syndromes might help to understand the complex action of tremor generator networks.
Collapse
Affiliation(s)
- Andrea Kovács
- Department of Neurology, National Institute of Clinical Neurosciences.,János Szentágothai Doctoral School of Neurosciences, Semmelweis University
| | | | - Anna Kelemen
- Department of Neurology, National Institute of Clinical Neurosciences
| | | | - Anna Szűcs
- Department of Neurology, National Institute of Clinical Neurosciences
| | - Anita Kamondi
- Department of Neurology, National Institute of Clinical Neurosciences.,Department of Neurology, Semmelweis University
| |
Collapse
|
36
|
Odgerel Z, Sonti S, Hernandez N, Park J, Ottman R, Louis ED, Clark LN. Whole genome sequencing and rare variant analysis in essential tremor families. PLoS One 2019; 14:e0220512. [PMID: 31404076 PMCID: PMC6690583 DOI: 10.1371/journal.pone.0220512] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/17/2019] [Indexed: 11/19/2022] Open
Abstract
Essential tremor (ET) is one of the most common movement disorders. The etiology of ET remains largely unexplained. Whole genome sequencing (WGS) is likely to be of value in understanding a large proportion of ET with Mendelian and complex disease inheritance patterns. In ET families with Mendelian inheritance patterns, WGS may lead to gene identification where WES analysis failed to identify the causative single nucleotide variant (SNV) or indel due to incomplete coverage of the entire coding region of the genome, in addition to accurate detection of larger structural variants (SVs) and copy number variants (CNVs). Alternatively, in ET families with complex disease inheritance patterns with gene x gene and gene x environment interactions enrichment of functional rare coding and non-coding variants may explain the heritability of ET. We performed WGS in eight ET families (n = 40 individuals) enrolled in the Family Study of Essential Tremor. The analysis included filtering WGS data based on allele frequency in population databases, rare SNV and indel classification and association testing using the Mixed-Model Kernel Based Adaptive Cluster (MM-KBAC) test. A separate analysis of rare SV and CNVs segregating within ET families was also performed. Prioritization of candidate genes identified within families was performed using phenolyzer. WGS analysis identified candidate genes for ET in 5/8 (62.5%) of the families analyzed. WES analysis in a subset of these families in our previously published study failed to identify candidate genes. In one family, we identified a deleterious and damaging variant (c.1367G>A, p.(Arg456Gln)) in the candidate gene, CACNA1G, which encodes the pore forming subunit of T-type Ca(2+) channels, CaV3.1, and is expressed in various motor pathways and has been previously implicated in neuronal autorhythmicity and ET. Other candidate genes identified include SLIT3 which encodes an axon guidance molecule and in three families, phenolyzer prioritized genes that are associated with hereditary neuropathies (family A, KARS, family B, KIF5A and family F, NTRK1). Functional studies of CACNA1G and SLIT3 suggest a role for these genes in ET disease pathogenesis.
Collapse
Affiliation(s)
- Zagaa Odgerel
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Shilpa Sonti
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Nora Hernandez
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, United States of America
| | - Jemin Park
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, United States of America
| | - Ruth Ottman
- G.H Sergievsky Center, Columbia University, New York, NY, United States of America
- Department of Neurology, College of Physicians and Surgeons, Columbia University New York, NY, United States of America
- Department of Epidemiology, Mailman School of Public Health, Columbia University, NY, United States of America
- Division of Epidemiology, New York State Psychiatric Institute, New York, NY, United States of America
| | - Elan D. Louis
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, United States of America
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, United States of America
| | - Lorraine N. Clark
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
- * E-mail:
| |
Collapse
|
37
|
Abstract
Click here to listen to the Podcast Essential tremor is the most common form of tremor in humans. Given neurologists' high exposure to this condition, and its seemingly straightforward phenotype, it might seem easy to diagnose. However, 30%-50 % of patients labelled as having 'essential tremor' have other diagnoses, mostly Parkinson's disease and dystonia. The tremor of essential tremor is neither non-descript nor featureless but is multifaceted and highly patterned. This review focuses on its clinical features, beginning with a discussion of tremors and then briefly discussing its additional motor features, and presents several aids to help distinguish essential tremor from Parkinson's disease and dystonia. Careful attention to certain clinical nuances will aid the diagnosis and care of patients with essential tremor.
Collapse
Affiliation(s)
- Elan D Louis
- Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA .,Center for Neuroepidemiology and Clinical Neurological Research, 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
| |
Collapse
|
38
|
Abstract
It is a clinical experience that acute lesions of the cerebellum induce pathological tremor, which tends to improve. However, quantitative characteristics, imaging correlates, and recovery of cerebellar tremor have not been systematically investigated. We studied the prevalence, quantitative parameters measured with biaxial accelerometry, and recovery of pathological tremor in 68 patients with lesions affecting the cerebellum. We also investigated the correlation between the occurrence and characteristics of tremor and lesion localization using 3D T1-weighted MRI images which were normalized and segmented according to a spatially unbiased atlas template for the cerebellum. Visual assessment detected pathological tremor in 19% while accelerometry in 47% of the patients. Tremor was present both in postural and intentional positions, but never at rest. Two types of pathological tremor were distinguished: (1) low-frequency tremor in 36.76% of patients (center frequency 2.66 ± 1.17 Hz) and (2) normal frequency-high-intensity tremor in 10.29% (center frequency 8.79 ± 1.43 Hz). The size of the lesion did not correlate with the presence or severity of tremor. Involvement of the anterior lobe and lobule VI was related to high tremor intensity. In all followed up patients with acute cerebellar ischemia, the tremor completely recovered within 8 weeks. Our results indicate that cerebellar lesions might induce pathological postural and intentional tremor of 2-3 Hz frequency. Due to its low frequency and low amplitude, quantitative tremorometry is neccessary to properly identify it. There is no tight correlation between lesion localization and quantitative characteristics of cerebellar tremor.
Collapse
|
39
|
Bareš M, Apps R, Avanzino L, Breska A, D'Angelo E, Filip P, Gerwig M, Ivry RB, Lawrenson CL, Louis ED, Lusk NA, Manto M, Meck WH, Mitoma H, Petter EA. Consensus paper: Decoding the Contributions of the Cerebellum as a Time Machine. From Neurons to Clinical Applications. CEREBELLUM (LONDON, ENGLAND) 2019; 18:266-286. [PMID: 30259343 DOI: 10.1007/s12311-018-0979-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Time perception is an essential element of conscious and subconscious experience, coordinating our perception and interaction with the surrounding environment. In recent years, major technological advances in the field of neuroscience have helped foster new insights into the processing of temporal information, including extending our knowledge of the role of the cerebellum as one of the key nodes in the brain for this function. This consensus paper provides a state-of-the-art picture from the experts in the field of the cerebellar research on a variety of crucial issues related to temporal processing, drawing on recent anatomical, neurophysiological, behavioral, and clinical research.The cerebellar granular layer appears especially well-suited for timing operations required to confer millisecond precision for cerebellar computations. This may be most evident in the manner the cerebellum controls the duration of the timing of agonist-antagonist EMG bursts associated with fast goal-directed voluntary movements. In concert with adaptive processes, interactions within the cerebellar cortex are sufficient to support sub-second timing. However, supra-second timing seems to require cortical and basal ganglia networks, perhaps operating in concert with cerebellum. Additionally, sensory information such as an unexpected stimulus can be forwarded to the cerebellum via the climbing fiber system, providing a temporally constrained mechanism to adjust ongoing behavior and modify future processing. Patients with cerebellar disorders exhibit impairments on a range of tasks that require precise timing, and recent evidence suggest that timing problems observed in other neurological conditions such as Parkinson's disease, essential tremor, and dystonia may reflect disrupted interactions between the basal ganglia and cerebellum.The complex concepts emerging from this consensus paper should provide a foundation for further discussion, helping identify basic research questions required to understand how the brain represents and utilizes time, as well as delineating ways in which this knowledge can help improve the lives of those with neurological conditions that disrupt this most elemental sense. The panel of experts agrees that timing control in the brain is a complex concept in whom cerebellar circuitry is deeply involved. The concept of a timing machine has now expanded to clinical disorders.
Collapse
Affiliation(s)
- Martin Bareš
- First Department of Neurology, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic.
- Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, USA.
| | - Richard Apps
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Laura Avanzino
- Department of Experimental Medicine, Section of Human Physiology and Centro Polifunzionale di Scienze Motorie, University of Genoa, Genoa, Italy
- Centre for Parkinson's Disease and Movement Disorders, Ospedale Policlinico San Martino, Genoa, Italy
| | - Assaf Breska
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, USA
| | - Egidio D'Angelo
- Neurophysiology Unit, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Brain Connectivity Center, Fondazione Istituto Neurologico Nazionale Casimiro Mondino (IRCCS), Pavia, Italy
| | - Pavel Filip
- First Department of Neurology, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Marcus Gerwig
- Department of Neurology, University of Duisburg-Essen, Duisburg, Germany
| | - Richard B Ivry
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, USA
| | - Charlotte L Lawrenson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Elan D Louis
- 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
| | - Nicholas A Lusk
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Mario Manto
- Department of Neurology, CHU-Charleroi, Charleroi, Belgium -Service des Neurosciences, UMons, Mons, Belgium
| | - Warren H Meck
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan
| | - Elijah A Petter
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| |
Collapse
|
40
|
Cerebellar repetitive transcranial magnetic stimulation for patients with essential tremor. Parkinsonism Relat Disord 2019; 64:304-307. [PMID: 30928207 DOI: 10.1016/j.parkreldis.2019.03.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 01/19/2023]
Abstract
INTRODUCTION The possibility of repetitive transcranial magnetic stimulation (rTMS) as an alternative therapy for essential tremor (ET) patients has emerged. However, its effect on medicated ET patients is lacking. The aim of this pilot study was to investigate the effect of cerebellar low-frequency rTMS as an "add-on" treatment. METHODS In this single-blinded, randomized, sham-controlled pilot study, patients with ET were randomized into two groups, one receiving real-rTMS and the other sham-rTMS. For 5 days, 1200 stimulations per day were applied to the bilateral cerebellar hemispheres at an intensity of 90% of the resting motor threshold (RMT) with a frequency of 1-Hz. Motor evoked potentials (MEPs) and the Fahn-Tolosa-Marin tremor rating scales (TRS) were measured before, immediately, and 4 weeks after the completion of the rTMS procedures. All patients continued taking medications during all procedures. RESULTS Among 22 patients, 12 and 10 patients were randomized into the real- and sham-rTMS groups, respectively. Repeated analysis of variance (ANOVA) measurements showed that the total TRS, TRS-A and B were changed both in real and sham-rTMS groups without interaction between time and group. TRS-C and MEPs, were not significantly changed at each follow-up point in either the real or sham-rTMS sessions. CONCLUSION We conclude that cerebellar low-frequency rTMS is safe, but has no significant effect as an "add-on" therapy in patients with ET.
Collapse
|
41
|
Filip P, Gallea C, Lehéricy S, Lungu O, Bareš M. Neural Scaffolding as the Foundation for Stable Performance of Aging Cerebellum. THE CEREBELLUM 2019; 18:500-510. [DOI: 10.1007/s12311-019-01015-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
42
|
Goetz L, Chabardès S. In Reply: Deep Brain Stimulation of the Pedunculopontine Nucleus Area in Parkinson Disease: Magnetic Resonance Imaging-Based Anatomoclinical Correlations and Optimal Target. Neurosurgery 2019; 84:E106-E107. [PMID: 30445622 DOI: 10.1093/neuros/nyy518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Laurent Goetz
- Grenoble Institute of Neurosciences INSERM U1216 CEA-UJF-CHUGA Grenoble, France.,University Grenoble Alpes Grenoble, France.,CERVO Brain Research CenterInstitut Universitaire en Santé Mentale de QuébecDepartment of Psychiatry and NeuroscienceUniversité Laval Québec City, Canada
| | - Stéphan Chabardès
- Grenoble Institute of Neurosciences INSERM U1216 CEA-UJF-CHUGA Grenoble, France.,University Grenoble Alpes Grenoble, France.,Department of NeurosurgeryCentre Hospitalier Universitaire Grenoble Alpes Grenoble, France.,Clinatec-CEA-LetiGrenoble, France
| |
Collapse
|
43
|
Fernandes TMP, Felismino DDSF, Almeida NLD, Santos NAD. Percepção Visual no Tremor Essencial: Uma Revisão Sistemática. PSICOLOGIA: TEORIA E PESQUISA 2019. [DOI: 10.1590/0102.3772e35210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RESUMO Investigou-se a relação entre percepção visual e tremor essencial (TE). Realizou-se uma revisão dos estudos publicados sobre o tema nas bases de dados PubMed, BIREME, CINAHL, Web of Science, PsycINFO, SciELO, SCOPUS e ELSEVIER desde a origem até 05 de janeiro de 2017. A triagem, extração de dados e avaliação foram realizadas por dois revisores. Para avaliar a qualidade dos estudos utilizou-se as diretrizes do National Institutes of Health (NIH). De 132 estudos potencialmente elegíveis, 12 foram selecionados de acordo com os critérios de elegibilidade. Os resultados indicaram que pessoas com TE apresentam baixa sensibilidade visual quando comparados com indivíduos saudáveis, apesar de não apresentarem prejuízos na visão de cores. Apesar da heterogeneidade dos dados, observamos que existem prejuízos visuais em pessoas com TE e estes podem ser uma das principais características clínicas não-motoras.
Collapse
|
44
|
van Dun K, Mitoma H, Manto M. Cerebellar Cortex as a Therapeutic Target for Neurostimulation. THE CEREBELLUM 2018; 17:777-787. [PMID: 30276522 DOI: 10.1007/s12311-018-0976-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Non-invasive stimulation of the cerebellum is growingly applied both in the clinic and in research settings to modulate the activities of cerebello-cerebral loops. The anatomical location of the cerebellum, the high responsiveness of the cerebellar cortex to magnetic/electrical stimuli, and the implication of the cerebellum in numerous cerebello-cerebral networks make the cerebellum an ideal target for investigations and therapeutic purposes. In this mini-review, we discuss the potentials of cerebellar neuromodulation in major brain disorders in order to encourage large-scale sham-controlled research and explore this therapeutic aid further.
Collapse
Affiliation(s)
- Kim van Dun
- Clinical and Experimental Neurolinguistics, CLIN, Vrije Universiteit Brussels, Pleinlaan 2, 1050, Brussels, Belgium.
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium.,Service des Neurosciences, UMons, Mons, Belgium
| |
Collapse
|
45
|
Absence of Mutation Enrichment for Genes Phylogenetically Conserved in the Olivocerebellar Motor Circuitry in a Cohort of Canadian Essential Tremor Cases. Mol Neurobiol 2018; 56:4317-4321. [PMID: 30315477 DOI: 10.1007/s12035-018-1369-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/27/2018] [Indexed: 10/28/2022]
Abstract
Essential Tremor is a prevalent neurological disorder of unknown etiology. Studies suggest that genetic factors contribute to this pathology. To date, no causative mutations in a gene have been reproducibly reported. All three structures of the olivocerebellar motor circuitry have been linked to Essential Tremor. We postulated that genes enriched for their expression in the olivocerebellar circuitry would be more susceptible to harbor mutations in Essential Tremor patients. A list of 11 candidate genes, enriched for their expression in the olivocerebellar circuitry, was assessed for their variation spectrum and frequency in a cohort of Canadian Essential Tremor cases. Our results from this list of 11 candidate genes do not support an association for Essential Tremor in our cohort of Canadian cases. The heterogenic nature of ET and modest size of the cohort used in this study are two confounding factors that could explain these results.
Collapse
|
46
|
Pan MK, Ni CL, Wu YC, Li YS, Kuo SH. Animal Models of Tremor: Relevance to Human Tremor Disorders. Tremor Other Hyperkinet Mov (N Y) 2018; 8:587. [PMID: 30402338 PMCID: PMC6214818 DOI: 10.7916/d89s37mv] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/10/2018] [Indexed: 12/17/2022] Open
Abstract
Background Tremor is the most common movement disorder; however, the pathophysiology of tremor remains elusive. While several neuropathological alterations in tremor disorders have been observed in post-mortem studies of human brains, a full understanding of the relationship between brain circuitry alterations and tremor requires testing in animal models. Additionally, tremor animal models are critical for our understanding of tremor pathophysiology, and/or to serve as a platform for therapy development. Methods A PubMed search was conducted in May 2018 to identify published papers for review. Results The methodology used in most studies on animal models of tremor lacks standardized measurement of tremor frequency and amplitude; instead, these studies are based on the visual inspection of phenotypes, which may fail to delineate tremor from other movement disorders such as ataxia. Of the animal models with extensive tremor characterization, harmaline-induced rodent tremor models provide an important framework showing that rhythmic and synchronous neuronal activities within the olivocerebellar circuit can drive action tremor. In addition, dopamine-depleted monkey and mouse models may develop rest tremor, highlighting the role of dopamine in rest tremor generation. Finally, other animal models of tremor have involvement of the cerebellar circuitry, leading to altered Purkinje cell physiology. Discussion Both the cerebellum and the basal ganglia are likely to play a role in tremor generation. While the cerebellar circuitry can generate rhythmic movements, the nigrostriatal system is likely to modulate the tremor circuit. Tremor disorders are heterogeneous in nature. Therefore, each animal model may represent a subset of tremor disorders, which collectively can advance our understanding of tremor.
Collapse
Affiliation(s)
- Ming-Kai Pan
- Department of Medical Research, National Taiwan University, Taipei, TW
| | - Chun-Lun Ni
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Yeuh-Chi Wu
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Yong-Shi Li
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| |
Collapse
|
47
|
Han Q, Hou Y, Shang H. A Voxel-Wise Meta-Analysis of Gray Matter Abnormalities in Essential Tremor. Front Neurol 2018; 9:495. [PMID: 29997568 PMCID: PMC6028592 DOI: 10.3389/fneur.2018.00495] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/06/2018] [Indexed: 02/05/2023] Open
Abstract
Objective: To identify the consistent gray matter (GM) volume changes from the whole brain voxel-based morphometry (VBM) studies on essential tremor (ET). Methods: The whole brain VBM studies comparing ET patients and healthy controls (HCs) were systematically searched in the PubMed, Embase and Web of Science from January 2000 to December 2017. Coordinates with significant differences in regional GM volume between ET patients and HCs were extracted from included studies and the meta-analysis was performed using effect size-based signed differential mapping (ES-SDM). Results: A total of 10 studies with 241 ET patients and 213 HCs were included in the meta-analysis. The consistent GM volume reduction was detected in the left precuneus extending to the left posterior cingulate gyrus. The subgroup meta-analysis which included studies performed on a 3.0 T scanner revealed significant GM volume increases in the bilateral frontal lobes, bilateral temporal lobes, left insula, left striatum and left pons, but obvious publication biases of these findings were detected through funnel plots and Egger's tests. Conclusions: The consistent result of our meta-analysis showed a structural damage in the left precuneus extending to the left posterior cingulate gyrus, which possibly played a role in the cognitive dysfunction and depression in ET patients. It might enhance our understanding of the pathophysiological mechanisms underlying ET.
Collapse
Affiliation(s)
- Qing Han
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Yanbing Hou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Huifang Shang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
48
|
Abstract
Essential Tremor (ET) is one of the most common neurological diseases, with an estimated 7 million affected individuals in the US; the pathophysiology of the disorder is poorly understood. Recently, we identified a mutation (KCNS2 (Kv9.2), c.1137 T > A, p.(D379E) in an electrically silent voltage-gated K+ channel α-subunit, Kv9.2, in a family with ET, that modulates the activity of Kv2 channels. We have produced transgenic Drosophila lines that express either the human wild type Kv9.2 (hKv9.2) or the ET causing mutant Kv9.2 (hKv9.2-D379E) subunit in all neurons. We show that the hKv9.2 subunit modulates activity of endogenous Drosophila K+ channel Shab. The mutant hKv9.2-D379E subunit showed significantly higher levels of Shab inactivation and a higher frequency of spontaneous firing rate consistent with neuronal hyperexcitibility. We also observed behavioral manifestations of nervous system dysfunction including effects on night time activity and sleep. This functional data further supports the pathogenicity of the KCNS2 (p.D379E) mutation, consistent with our prior observations including co-segregation with ET in a family, a likely pathogenic change in the channel pore domain and absence from population databases. The Drosophila hKv9.2 transgenic model recapitulates several features of ET and may be employed to advance our understanding of ET disease pathogenesis.
Collapse
|
49
|
Cameron E, Dyke JP, Hernandez N, Louis ED, Dydak U. Cerebral gray matter volume losses in essential tremor: A case-control study using high resolution tissue probability maps. Parkinsonism Relat Disord 2018; 51:85-90. [PMID: 29574086 DOI: 10.1016/j.parkreldis.2018.03.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/23/2018] [Accepted: 03/09/2018] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Essential tremor (ET) is increasingly recognized as a multi-dimensional disorder with both motor and non-motor features. For this reason, imaging studies are more broadly examining regions outside the cerebellar motor loop. Reliable detection of cerebral gray matter (GM) atrophy requires optimized processing, adapted to high-resolution magnetic resonance imaging (MRI). We investigated cerebral GM volume loss in ET cases using automated segmentation of MRI T1-weighted images. METHODS MRI was acquired on 47 ET cases and 36 controls. Automated segmentation and voxel-wise comparisons of volume were performed using Statistical Parametric Mapping (SPM) software. To improve upon standard protocols, the high-resolution International Consortium for Brain Mapping (ICBM) 2009a atlas and tissue probability maps were used to process each subject image. Group comparisons were performed: all ET vs. Controls, ET with head tremor (ETH) vs. Controls, and severe ET vs. Controls. An analysis of variance (ANOVA) was performed between ET with and without head tremor and controls. Age, sex, and Montreal Cognitive Assessment (MoCA) score were regressed out from each comparison. RESULTS We were able to consistently identify regions of cerebral GM volume loss in ET and in ET subgroups in the posterior insula, superior temporal gyri, cingulate cortex, inferior frontal gyri and other occipital and parietal regions. There were no significant increases in GM volume in ET in any comparisons with controls. CONCLUSION This study, which uses improved methodologies, provides evidence that GM volume loss in ET is present beyond the cerebellum, and in fact, is widespread throughout the cerebrum as well.
Collapse
Affiliation(s)
- Eric Cameron
- School of Health Sciences, Purdue University, 550 Stadium Mall Dr., West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 University Blvd., Indianapolis, IN 46202, USA
| | - Jonathan P Dyke
- Department of Radiology, Citigroup Biomedical Imaging Center, Weill Cornell Medicine, 516 E. 72nd St., New York, NY 10021, USA
| | - Nora Hernandez
- Department of Neurology, Yale School of Medicine, Yale University, P.O. Box 208018, New Haven, CT 06520, USA
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, P.O. Box 208018, New Haven, CT 06520, USA; Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, 600 College St., P.O. Box 208034, New Haven, CT 06520, USA; Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06510, USA
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, 550 Stadium Mall Dr., West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 University Blvd., Indianapolis, IN 46202, USA.
| |
Collapse
|
50
|
Hashimoto T, Muralidharan A, Yoshida K, Goto T, Yako T, Baker KB, Vitek JL. Neuronal activity and outcomes from thalamic surgery for spinocerebellar ataxia. Ann Clin Transl Neurol 2018; 5:52-63. [PMID: 29376092 PMCID: PMC5771317 DOI: 10.1002/acn3.508] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/30/2017] [Accepted: 10/31/2017] [Indexed: 11/11/2022] Open
Abstract
Objectives We investigated the effects of deep brain stimulation (DBS) or lesions of the ventral intermediate nucleus (Vim) of the thalamus for spinocerebellar ataxia (SCA) and examined the pathophysiological role of neuronal activity of the Vim underlying ataxia. Methods Five patients with SCA with cortical atrophy (ages 60-69 years; 2 sporadic and three familial SCA) and five patients with essential tremor (ET) (ages 57-71 years) were treated with Vim surgery. Intraoperatively, we recorded neuronal activity from single neurons in the Vim thalamus while patients were at rest and compared the physiological properties of those neurons between patients with SCA and those with ET. Results Postsurgery mean scores for the Fahn-Tolosa-Marin Tremor Scale were improved from 78 to 44 in SCA patients and from 54 to 21 in ET patients. Stronger stimulation was necessary to optimize outcomes in SCA as compared to ET patients. We analyzed 68 Vim neurons in SCA and 60 Vim neurons in ET. Mean discharge rates, burst characteristics, and oscillatory activity were similar for both patient groups, however, we observed that the ratio of cells responding to passive manipulation was significantly smaller (P = 0.0001) in SCA (22%) than in ET (71%). Interpretation Thalamic surgery led to a significant improvement in tremor in SCA patients. One potential mechanism underlying ataxia in SCA may be disruption of cerebellar sensory feedback, which modulates motor commands in the cerebello-thalamo-cortical network.
Collapse
Affiliation(s)
| | - Abirami Muralidharan
- Neuromodulation Research CenterDepartment of NeurologyUniversity of MinnesotaMinneapolisMinnesota
| | - Kunihiro Yoshida
- Department of Brain Disease ResearchShinshu University School of MedicineMatsumotoJapan
| | - Tetsuya Goto
- Department of NeurosurgeryShinshu University School of MedicineMatsumotoJapan
| | - Takehiro Yako
- Department of NeurosurgeryAizawa HospitalMatsumotoJapan
| | | | - Jerrold L. Vitek
- Neuromodulation Research CenterDepartment of NeurologyUniversity of MinnesotaMinneapolisMinnesota
| |
Collapse
|