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Prasad S, Saini J, Bharath RD, Pal PK. Differential patterns of functional connectivity in tremor dominant Parkinson's disease and essential tremor plus. J Neural Transm (Vienna) 2024; 131:781-789. [PMID: 38430265 DOI: 10.1007/s00702-024-02761-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 02/23/2024] [Indexed: 03/03/2024]
Abstract
Tremor dominant Parkinson's disease (TDPD) and essential tremor plus (ETP) syndrome are commonly encountered tremor dominant neurological disorders. Although the basal ganglia thalamocortical (BGTC) and cerebello thalamocortical (CTC) networks are implicated in tremorogenesis, the extent of functional connectivity alterations across disorders is uncertain. This study aims to evaluate functional connectivity of the BGTC and CTC in TDPD and ETP. Resting state functional MRI was acquired for 25 patients with TDPD, ETP and 22 healthy controls (HC). Following pre-processing and denoising, seed-to-voxel based connectivity was carried out at FDR < 0.05 using ROIs belonging to the BGTC and CTC. Fahn-Tolosa-Marin tremor rating scale (FTMRS) was correlated with the average connectivity values at FDR < 0.05. Compared to HC, TDPD showed decreased connectivity between cerebellum and pre, post central gyrus. While, ETP showed decreased connectivity between pallidum and occipital cortex, precuneus, cuneus compared to HC. In comparison to ETP, TDPD showed increased connectivity between precentral gyrus, pallidum, SNc with the default mode network (DMN), and decreased connectivity between cerebellum with superior, middle frontal gyrus was observed. Tremor severity positively correlated with connectivity between SNc and DMN in TDPD, and negatively correlated with pallidal connectivity in ETP. Pattern of BGTC, CTC involvement is differential i.e., higher connectivity of the BGTC nodes in TDPD, and higher connectivity of cerebellar nodes in ETP. The interesting observation of pallidal involvement in ETP suggests the role of BGTC in the pathogenesis of ETP, and indicated similarities in concepts of tremor genesis in TDPD and ETP.
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Affiliation(s)
- Shweta Prasad
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Jitender Saini
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India.
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Gurgone S, De Salvo S, Bonanno L, Muscarà N, Acri G, Caridi F, Paladini G, Borzelli D, Brigandì A, La Torre D, Sorbera C, Anfuso C, Di Lorenzo G, Venuti V, d'Avella A, Marino S. Changes in cerebral cortex activity during a simple motor task after MRgFUS treatment in patients affected by essential tremor and Parkinson's disease: a pilot study using functional NIRS. Phys Med Biol 2024; 69:025014. [PMID: 38100845 DOI: 10.1088/1361-6560/ad164e] [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: 05/17/2023] [Accepted: 12/15/2023] [Indexed: 12/17/2023]
Abstract
Objective.Magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS) is a non-invasive thermal ablation method that involves high-intensity focused ultrasound surgery (FUS) and Magnetic Resonance Imaging for anatomical imaging and real-time thermal mapping. This technique is widely employed for the treatment of patients affected by essential tremor (ET) and Parkinson's disease (PD). In the current study, functional near-infrared spectroscopy (fNIRS) was used to highlight hemodynamics changes in cerebral cortex activity, during a simple hand motor task, i.e. unimanual left and right finger-tapping, in ET and PD patients.Approach.All patients were evaluated before, one week and one month after MRgFUS treatment.Main results.fNIRS revealed cerebral hemodynamic changes one week and one month after MRgFUS treatment, especially in the ET group, that showed a significant clinical improvement in tremor clinical scores.Significance.To our knowledge, our study is the first that showed the use of fNIRS system to measure the cortical activity changes following unilateral ventral intermediate nucleus thalamotomy after MRgFUS treatment. Our findings showed that therapeutic MRgFUS promoted the remodeling of neuronal networks and changes in cortical activity in association with symptomatic improvements.
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Affiliation(s)
- Sergio Gurgone
- Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology, 1-4, Yamadaoka, Suita City, 565-0871 Osaka, Japan
| | - Simona De Salvo
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Lilla Bonanno
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Nunzio Muscarà
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Giuseppe Acri
- Dipartimento di Scienze Biomediche, Odontoiatriche, e delle Immagini Morfologiche e Funzionali, Università degli Studi di Messina, c/o A.O.U. Policlinico 'G. Martino' Via Consolare Valeria 1, I-98125 Messina, Italy
| | - Francesco Caridi
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università degli Studi di Messina, V.le F. Stagno D'Alcontres 31, I-98166 Messina, Italy
| | - Giuseppe Paladini
- Dipartimento di Fisica e Astronomia 'Ettore Majorana', Università degli Studi di Catania, Via S. Sofia 64, I-95123 Catania, Italy
| | - Daniele Borzelli
- Dipartimento di Scienze Biomediche, Odontoiatriche, e delle Immagini Morfologiche e Funzionali, Università degli Studi di Messina, c/o A.O.U. Policlinico 'G. Martino' Via Consolare Valeria 1, I-98125 Messina, Italy
- Laboratorio di Fisiologia Neuromotoria, IRCCS Fondazione Santa Lucia, Via Ardeatina 306-354, I-00179 Roma, Italy
| | - Amelia Brigandì
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Domenico La Torre
- Dipartimento di Scienze Mediche e Chirurgiche, Istituto di Neurochirurgia, Università degli Studi 'Magna Graecia' di Catanzaro, Viale Europa, I-88100 Catanzaro, Italy
| | - Chiara Sorbera
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Carmelo Anfuso
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Giuseppe Di Lorenzo
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
| | - Valentina Venuti
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università degli Studi di Messina, V.le F. Stagno D'Alcontres 31, I-98166 Messina, Italy
| | - Andrea d'Avella
- Dipartimento di Scienze Biomediche, Odontoiatriche, e delle Immagini Morfologiche e Funzionali, Università degli Studi di Messina, c/o A.O.U. Policlinico 'G. Martino' Via Consolare Valeria 1, I-98125 Messina, Italy
- Laboratorio di Fisiologia Neuromotoria, IRCCS Fondazione Santa Lucia, Via Ardeatina 306-354, I-00179 Roma, Italy
| | - Silvia Marino
- IRCCS Centro Neurolesi 'Bonino-Pulejo', Via Palermo, Ctr. Casazza, S.S. 113, I-98121 Messina, Italy
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McGurrin P, Norato G, Thompson-Westra J, McCrossin G, Lines E, Lungu C, Pandey S, Tinaz S, Voller B, Ramchandani V, Hallett M, Haubenberger D. Objective response to ethanol in essential tremor: results from a standardized ethanol challenge study. Ann Clin Transl Neurol 2024; 11:156-168. [PMID: 38087917 PMCID: PMC10791018 DOI: 10.1002/acn3.51943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 10/29/2023] [Indexed: 01/17/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Ethanol has been reported to improve tremor severity in approximately two thirds of patients with essential tremor (ET), but the accuracy of that proportion is not certain and the mechanism of action is unknown. The goal of this study was to investigate alcohol response on tremor by applying an a priori objective response definition and subsequently to describe the responder rate to a standardized ethanol dose in a cohort of 85 ET patients. A secondary analysis evaluated other tremor and nontremor features, including demographics, tremor intensity, breath alcohol concentration, nontremor effects of alcohol, self-reported responder status to ethanol, and prior ethanol exposure. METHODS This was a prospective, open-label, single-dose challenge of oral ethanol during which motor and nonmotor measurements were obtained starting immediately prior to ethanol administration and subsequently every 20 min for 120 min. We defined tremor reduction as a 35% decline in power in the patient's tremor frequency recorded during spiral drawing 60 min after ethanol administration. RESULTS In total, 80% of patients were considered alcohol responsive using our objective definition. Responder status and change in the objective tremor metrics were significantly correlated with the change in breath alcohol concentration levels after ethanol administration, but no other relationships to nontremor metrics were found. DISCUSSION A high percentage of patients actually respond to acute ethanol. However, their self-reported response does not correlate well with their objective response. Objective response correlates with breath alcohol level but not with sedation, indicating a specific effect of ethanol on tremor.
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Affiliation(s)
- Patrick McGurrin
- Office of the Senior Vice President and Provost, University of Maryland, College Park, Maryland, USA
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Gina Norato
- Office of the Clinical Director, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Johanna Thompson-Westra
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
- Department of Family Medicine, University of Colorado Anschutz, Aurora, Colorado, USA
| | - Gayle McCrossin
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
- Department of Rehabilitation Medicine, Office of Strategic Research, Applied Physiology and Exercise Science Lab, National Institutes of Health, Bethesda, Maryland, USA
| | - Emily Lines
- Department of Family Medicine, University of Colorado Anschutz, Aurora, Colorado, USA
| | - Codrin Lungu
- Division of Clinical Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Sanjay Pandey
- Department of Neurology and Stroke Medicine, Amrita Hospital, Faridabad, India
| | - Sule Tinaz
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Vijay Ramchandani
- Human Psychopharmacology Laboratory, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Dietrich Haubenberger
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
- Office of the Clinical Director, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
- Department of Neurosciences, University of San Diego California, La Jolla, California, USA
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Fanning A, Kuo SH. Clinical Heterogeneity of Essential Tremor: Understanding Neural Substrates of Action Tremor Subtypes. CEREBELLUM (LONDON, ENGLAND) 2023:10.1007/s12311-023-01551-3. [PMID: 37022657 PMCID: PMC10556200 DOI: 10.1007/s12311-023-01551-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/21/2023] [Indexed: 04/07/2023]
Abstract
Essential tremor (ET) is a common movement disorder affecting millions of people. Studies of ET patients and perturbations in animal models have provided a foundation for the neural networks involved in its pathophysiology. However, ET encompasses a wide variability of phenotypic expression, and this may be the consequence of dysfunction in distinct subcircuits in the brain. The cerebello-thalamo-cortical circuit is a common substrate for the multiple subtypes of action tremor. Within the cerebellum, three sets of cerebellar cortex-deep cerebellar nuclei connections are important for tremor. The lateral hemispheres and dentate nuclei may be involved in intention, postural and isometric tremor. The intermediate zone and interposed nuclei could be involved in intention tremor. The vermis and fastigial nuclei could be involved in head and proximal upper extremity tremor. Studying distinct cerebellar circuitry will provide important framework for understanding the clinical heterogeneity of ET.
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Affiliation(s)
- Alexander Fanning
- Department of Neurology, Columbia University, New York, NY, 10032, USA
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, 10032, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY, 10032, USA.
- Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, 10032, USA.
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Swytink-Binnema CA, Rockel CP, Martino D, Dukelow SP, Pike GB, Kiss ZHT. Limb Preference Changes after Focused-Ultrasound Thalamotomy for Tremor. Mov Disord 2023. [PMID: 36947685 DOI: 10.1002/mds.29350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/30/2023] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND Magnetic resonance-guided focused-ultrasound (MRgFUS) thalamotomy is an effective treatment for essential and other tremors. It targets the ventrointermedius (Vim) nucleus, which is the thalamic relay in a proprioceptive pathway, and contains kinesthetic cells. Although MRgFUS thalamotomy reduces some risks associated with more invasive surgeries, it still has side effects, such as balance and gait disturbances; these may be caused by the lesion impacting proprioception. OBJECTIVES Our aim was to quantitatively measure the effects of MRgFUS on proprioception and limb use in essential tremor patients. We hypothesized that this thalamotomy alters proprioception, because the sensorimotor Vim thalamus is lesioned. METHODS Proprioception was measured using the Kinarm exoskeleton robot in 18 patients. Data were collected pre-operatively, and then 1 day, 3 months, and 1 year after surgery. Patients completed four tasks, assessing motor coordination and postural control, goal-directed movement and bimanual planning, position sense, and kinesthesia. RESULTS Immediately after surgery there were changes in posture speed (indicating tremor improvement), and in bimanual hand use, with the untreated limb being preferred. However, these measures returned to pre-operative baseline over time. There were no changes in parameters related to proprioception. None of these measures correlated with lesion size or lesion-overlap with the dentato-rubro-thalamic tract. CONCLUSIONS This is the first quantitative assessment of proprioception and limb preference following MRgFUS thalamotomy. Our results suggest that focused-ultrasound lesioning of the Vim thalamus does not degrade proprioception but alters limb preference. This change may indicate a required "relearning" in the treated limb, because the effect is transient. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Catherine A Swytink-Binnema
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Conrad P Rockel
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Davide Martino
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sean P Dukelow
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - G Bruce Pike
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Zelma H T Kiss
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Sushkova OS, Morozov AA, Kershner IA, Khokhlova MN, Gabova AV, Karabanov AV, Chigaleichick LA, Illarioshkin SN. Investigation of Phase Shifts Using AUC Diagrams: Application to Differential Diagnosis of Parkinson's Disease and Essential Tremor. SENSORS (BASEL, SWITZERLAND) 2023; 23:1531. [PMID: 36772568 PMCID: PMC9921843 DOI: 10.3390/s23031531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
This study was motivated by the well-known problem of the differential diagnosis of Parkinson's disease and essential tremor using the phase shift between the tremor signals in the antagonist muscles of patients. Different phase shifts are typical for different diseases; however, it remains unclear how this parameter can be used for clinical diagnosis. Neurophysiological papers have reported different estimations of the accuracy of this parameter, which varies from insufficient to 100%. To address this issue, we developed special types of area under the ROC curve (AUC) diagrams and used them to analyze the phase shift. Different phase estimations, including the Hilbert instantaneous phase and the cross-wavelet spectrum mean phase, were applied. The results of the investigation of the clinical data revealed several regularities with opposite directions in the phase shift of the electromyographic signals in patients with Parkinson's disease and essential tremor. The detected regularities provide insights into the contradictory results reported in the literature. Moreover, the developed AUC diagrams show the potential for the investigation of neurodegenerative diseases related to the hyperkinetic movements of the extremities and the creation of high-accuracy methods of clinical diagnosis.
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Affiliation(s)
- Olga S. Sushkova
- Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow, Russia
| | - Alexei A. Morozov
- Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow, Russia
| | - Ivan A. Kershner
- Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow, Russia
| | - Margarita N. Khokhlova
- Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow, Russia
| | - Alexandra V. Gabova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Butlerova 5A, 117485 Moscow, Russia
| | - Alexei V. Karabanov
- FSBI “Research Center of Neurology”, Volokolamskoe Shosse 80, 125367 Moscow, Russia
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Sharifi S, Luft F, de Boer L, Buijink AWG, Mugge W, Schouten AC, Heida T, Bour LJ, van Rootselaar AF. Closing the loop: Novel quantitative fMRI approach for manipulation of the sensorimotor loop in tremor. Neuroimage 2022; 262:119554. [PMID: 35963505 DOI: 10.1016/j.neuroimage.2022.119554] [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: 10/24/2021] [Revised: 07/29/2022] [Accepted: 08/09/2022] [Indexed: 10/31/2022] Open
Abstract
Tremor is thought to be an effect of oscillatory activity within the sensorimotor network. To date, the underlying pathological brain networks are not fully understood. Disentangling tremor activity from voluntary motor output and sensorimotor feedback systems is challenging. To better understand the intrinsic sensorimotor fingerprint underlying tremor, we aimed to disentangle the sensorimotor system into driving (motor) and feedback/compensatory (sensory) neuronal involvement, and aimed to pinpoint tremor activity in essential tremor (ET) and tremor-dominant Parkinson's disease (PD) with a novel closed-loop approach. Eighteen ET patients, 14 tremor-dominant PD patients, and 18 healthy controls were included. An MR-compatible wrist manipulator was employed during functional MRI (fMRI) while muscle activity during (in)voluntary movements was concurrently recorded using electromyography (EMG). Tremor was quantified based on EMG and correlated to brain activity. Participants performed three tasks: an active wrist motor task, a passive wrist movement task, and rest (no wrist movement). The results in healthy controls proved that our experimental paradigm activated the expected motor and sensory networks separately using the active (motor) and passive (sensory) task. ET patients showed similar patterns of activation within the motor and sensory networks. PD patients had less activity during the active motor task in the cerebellum and basal ganglia compared to ET and healthy controls. EMG showed that in ET, tremor fluctuations correlated positively with activity in the inferior olive region, and that in PD tremor fluctuations correlated positively with cerebellar activity. Our novel approach with an MR-compatible wrist manipulator, allowed to investigate the involvement of the motor and sensory networks separately, and as such to better understand tremor pathophysiology. In ET sensorimotor network function did not differ from healthy controls. PD showed less motor-related activity. Focusing on tremor, our results indicate involvement of the inferior olive in ET tremor modulation, and cerebellar involvement in PD tremor modulation.
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Affiliation(s)
- S Sharifi
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC, Amsterdam Neuroscience, University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, Amsterdam 1100 DD, the Netherlands; BIC Brain Imaging Center, Academic Medical Center, Amsterdam, the Netherlands.
| | - F Luft
- Department of Biomedical Signals and Systems, TechMed Centre, University of Twente, Enschede, the Netherlands; BIC Brain Imaging Center, Academic Medical Center, Amsterdam, the Netherlands
| | - L de Boer
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC, Amsterdam Neuroscience, University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, Amsterdam 1100 DD, the Netherlands
| | - A W G Buijink
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC, Amsterdam Neuroscience, University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, Amsterdam 1100 DD, the Netherlands; BIC Brain Imaging Center, Academic Medical Center, Amsterdam, the Netherlands
| | - W Mugge
- Faculty of Mechanical, Maritime and Materials Engineering, Department of Biomechanical Engineering, Delft University of Technology, Delft, the Netherlands
| | - A C Schouten
- Faculty of Mechanical, Maritime and Materials Engineering, Department of Biomechanical Engineering, Delft University of Technology, Delft, the Netherlands
| | - T Heida
- Department of Biomedical Signals and Systems, TechMed Centre, University of Twente, Enschede, the Netherlands
| | - L J Bour
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC, Amsterdam Neuroscience, University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, Amsterdam 1100 DD, the Netherlands
| | - A F van Rootselaar
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC, Amsterdam Neuroscience, University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, Amsterdam 1100 DD, the Netherlands; BIC Brain Imaging Center, Academic Medical Center, Amsterdam, the Netherlands
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Cho HJ. Is essential tremor a degenerative or an electrical disorder? Electrical disorder. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:103-128. [PMID: 35750360 DOI: 10.1016/bs.irn.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Essential tremor (ET) is one of the most common movement disorders, yet we do not have a complete understanding of its pathophysiology. From a phenomenology standpoint, ET is an isolated tremor syndrome of bilateral upper limb action tremor with or without tremor in other body locations. ET is a pathological tremor that arises from excessive oscillation in the central motor network. The tremor network comprises of multiple brain regions including the inferior olive, cerebellum, thalamus, and motor cortex, and there is evidence that a dynamic oscillatory disturbance within this network leads to tremor. ET is a chronic disorder, and the natural history shows a slow progression of tremor intensity with age. There are reported data suggesting that ET follows the disease model of a neurodegenerative disorder, however whether ET is a degenerative or electrical disorder has been a subject of debate. In this chapter, we will review cumulative evidence that ET as a syndrome is a fundamentally electric disorder. The etiology is likely heterogenous and may not be primarily neurodegenerative.
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Affiliation(s)
- Hyun Joo Cho
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.
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Bellows S, Jimenez-Shahed J. Is essential tremor a disorder of GABA dysfunction? No. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:285-310. [PMID: 35750366 DOI: 10.1016/bs.irn.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although essential tremor is common, its underlying pathophysiology remains uncertain, and several hypotheses seek to explain the tremor mechanism. The GABA hypothesis states that disinhibition of deep cerebellar neurons due to reduced GABAergic input from Purkinje cells results in increased pacemaker activity, leading to rhythmic output to the thalamo-cortical circuit and resulting in tremor. However, some neuroimaging, spectroscopy, and pathology studies have not shown a clear or consistent GABA deficiency in essential tremor, and animal models have indicated that large reductions of Purkinje cell inhibition may improve tremor. Instead, tremor is increasingly attributable to dysfunction in oscillating networks, where altered (but not necessarily reduced) inhibitory signaling can result in tremor. Hypersynchrony of Purkinje cell activity may account for excessive oscillatory cerebellar output, with potential contributions along multiple sites of the olivocerebellar loop. Although older animal tremor models, such as harmaline tremor, have explored contributions from the inferior olivary body, increasing evidence has pointed to the role of aberrant climbing fiber synaptic organization in oscillatory cerebellar activity and tremor generation. New animal models such as hotfoot17j mice, which exhibit abnormal climbing fiber organization due to mutations in Grid2, have recapitulated many features of ET. Similar abnormal climbing fiber architecture and excessive cerebellar oscillations as measured by EEG have been found in humans with essential tremor. Further understanding of hypersynchrony and excessive oscillatory activity in ET phenotypes may lead to more targeted and effective treatment options.
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Pan MK, Kuo SH. Essential tremor: Clinical perspectives and pathophysiology. J Neurol Sci 2022; 435:120198. [PMID: 35299120 PMCID: PMC10363990 DOI: 10.1016/j.jns.2022.120198] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
Essential tremor (ET) is one of the most common neurological disorders and can be highly disabling. In recent years, studies on the clinical perspectives and pathophysiology have advanced our understanding of ET. Specifically, clinical heterogeneity of ET, with co-existence of tremor and other neurological features such as dystonia, ataxia, and cognitive dysfunction, has been identified. The cerebellum has been found to be the key brain region for tremor generation, and structural alterations of the cerebellum have been extensively studied in ET. Finally, four main ET pathophysiologies have been proposed: 1) environmental exposures to β-carboline alkaloids and the consequent olivocerebellar hyper-excitation, 2) cerebellar GABA deficiency, 3) climbing fiber synaptic pathology with related cerebellar oscillatory activity, 4) extra-cerebellar oscillatory activity. While these four theories are not mutually exclusive, they can represent distinctive ET subtypes, indicating multiple types of abnormal brain circuitry can lead to action tremor. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.
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Kosmowska B, Wardas J. The Pathophysiology and Treatment of Essential Tremor: The Role of Adenosine and Dopamine Receptors in Animal Models. Biomolecules 2021; 11:1813. [PMID: 34944457 PMCID: PMC8698799 DOI: 10.3390/biom11121813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/25/2021] [Accepted: 11/30/2021] [Indexed: 12/13/2022] Open
Abstract
Essential tremor (ET) is one of the most common neurological disorders that often affects people in the prime of their lives, leading to a significant reduction in their quality of life, gradually making them unable to independently perform the simplest activities. Here we show that current ET pharmacotherapy often does not sufficiently alleviate disease symptoms and is completely ineffective in more than 30% of patients. At present, deep brain stimulation of the motor thalamus is the most effective ET treatment. However, like any brain surgery, it can cause many undesirable side effects; thus, it is only performed in patients with an advanced disease who are not responsive to drugs. Therefore, it seems extremely important to look for new strategies for treating ET. The purpose of this review is to summarize the current knowledge on the pathomechanism of ET based on studies in animal models of the disease, as well as to present and discuss the results of research available to date on various substances affecting dopamine (mainly D3) or adenosine A1 receptors, which, due to their ability to modulate harmaline-induced tremor, may provide the basis for the development of new potential therapies for ET in the future.
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Affiliation(s)
| | - Jadwiga Wardas
- Department of Neuropsychopharmacology, Maj Institute of Pharmacology Polish Academy of Sciences, 31-343 Kraków, Poland;
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12
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van den Berg KRE, Helmich RC. The Role of the Cerebellum in Tremor - Evidence from Neuroimaging. Tremor Other Hyperkinet Mov (N Y) 2021; 11:49. [PMID: 34820148 PMCID: PMC8603856 DOI: 10.5334/tohm.660] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/28/2021] [Indexed: 01/04/2023] Open
Abstract
Background Neuroimaging research has played a key role in identifying which cerebral changes are associated with tremor. Here we will focus on the cerebellum, which may drive tremor oscillations, process tremor-related afferents, modulate activity in remote brain regions, or a combination. Methods On the 6th of October 2021, we conducted a PubMed search to select articles providing neuroimaging evidence for cerebellar involvement in essential tremor (ET), Parkinson's disease (PD) tremor, and dystonic tremor (DT). Results In ET, tremor-related activity is found in motor areas of the bilateral cerebellum, and altered functional connectivity within and outside the cerebellum correlates with tremor severity. Furthermore, ET is associated with cerebellar atrophy, but also with compensatory structural changes outside the cerebellum (e.g. supplementary motor area). In PD, tremor-related cerebellar activity and increased cerebello-thalamic coupling has been found. Emerging evidence suggests that the cerebellum plays a key role in dopamine-resistant rest tremor and in postural tremor. Cerebellar structural alterations have been identified in PD, but only some relate to tremor. DT is associated with more widespread cerebral networks than other tremor types. Discussion In ET, the cerebellum likely acts as an oscillator, potentially due to loss of inhibitory mechanisms. In contrast, in PD the cerebellum may be a modulator, which contributes to tremor oscillations by influencing the thalamo-cortical system. The precise role of the cerebellum in DT remains unclear. We recommend that future research measures tremor-related activity directly by combining electrophysiology with neuroimaging, while brain stimulation techniques may be used to establish causality. Highlights This review of neuroimaging studies has provided convincing evidence that the cerebellum plays a key role in the pathophysiology of ET, PD tremor, and dystonic tremor syndromes. This contribution may consist of driving tremor oscillations, processing tremor-related afferents, modulating activity in remote brain regions, or all the above.
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Affiliation(s)
- Kevin R. E. van den Berg
- Centre of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Rick C. Helmich
- Centre of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
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13
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Pietracupa S, Bologna M, Tommasin S, Berardelli A, Pantano P. The Contribution of Neuroimaging to the Understanding of Essential Tremor Pathophysiology: a Systematic Review. THE CEREBELLUM 2021; 21:1029-1051. [PMID: 34657271 DOI: 10.1007/s12311-021-01335-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/10/2021] [Indexed: 12/14/2022]
Abstract
Essential tremor (ET) is one of the most common movement disorders. Over the last 10 years, magnetic resonance imaging (MRI) has shed light on the structural and functional abnormalities possibly involved in ET pathophysiology. In this systematic review, we aimed to identify the cortical and subcortical structures involved and the role that different brain areas play in the pathophysiology of motor and non-motor ET features. We found that structural (grey and white matter) cerebellar damage and connectivity alterations between the cerebellum and various cortical areas play a role in both motor and non-motor symptoms of ET. In particular, many studies found an association between MRI findings and non-motor symptoms.
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Affiliation(s)
| | - Matteo Bologna
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Silvia Tommasin
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Alfredo Berardelli
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Patrizia Pantano
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
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14
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Di Pietro M, Russo M, Dono F, Carrarini C, Thomas A, Di Stefano V, Telese R, Bonanni L, Sensi SL, Onofrj M, Franciotti R. A Critical Review of Alien Limb-Related Phenomena and Implications for Functional Magnetic Resonance Imaging Studies. Front Neurol 2021; 12:661130. [PMID: 34566830 PMCID: PMC8458742 DOI: 10.3389/fneur.2021.661130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 07/06/2021] [Indexed: 11/27/2022] Open
Abstract
Consensus criteria on corticobasal degeneration (CBD) include alien limb (AL) phenomena. However, the gist of the behavioral features of AL is still “a matter of debate.” CBD-related AL has so far included the description of involuntary movements, frontal release phenomena (frontal AL), or asomatognosia (posterior or “real” AL). In this context, the most frequent symptoms are language and praxis deficits and cortical sensory misperception. However, asomatognosia requires, by definition, intact perception and cognition. Thus, to make a proper diagnosis of AL in the context of CBD, cognitive and language dysfunctions must be carefully verified and objectively assessed. We reviewed the current literature on AL in CBD and now propose that the generic use of the term AL should be avoided. This catchall AL term should instead be deconstructed. We propose that the term AL is appropriate to describe clinical features associated with specific brain lesions. More discrete sets of regionally bound clinical signs that depend on dysfunctions of specific brain areas need to be assessed and presented when posing the diagnosis. Thus, in our opinion, the AL term should be employed in association with precise descriptions of the accompanying involuntary movements, sensory misperceptions, agnosia-asomatognosia contents, and the presence of utilization behavior. The review also offers an overview of functional magnetic resonance imaging-based studies evaluating AL-related phenomena. In addition, we provide a complementary set of video clips depicting CBD-related involuntary movements that should not mistakenly be interpreted as signs of AL.
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Affiliation(s)
- Martina Di Pietro
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Mirella Russo
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Fedele Dono
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Claudia Carrarini
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Astrid Thomas
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Vincenzo Di Stefano
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Roberta Telese
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,IRCCS C. Mondino Foundation, Pavia, Italy
| | - Laura Bonanni
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Stefano L Sensi
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy
| | - Marco Onofrj
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. D'Annunzio" University, Chieti, Italy.,YDA Foundation, Institute of Immune Therapy and Advanced Biological Treatment, Pescara, Italy
| | - Raffaella Franciotti
- Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy
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15
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Holtbernd F, Shah NJ. Imaging the Pathophysiology of Essential Tremor-A Systematic Review. Front Neurol 2021; 12:680254. [PMID: 34220687 PMCID: PMC8244929 DOI: 10.3389/fneur.2021.680254] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/04/2021] [Indexed: 11/28/2022] Open
Abstract
Background: The pathophysiology underlying essential tremor (ET) still is poorly understood. Recent research suggests a pivotal role of the cerebellum in tremor genesis, and an ongoing controversy remains as to whether ET constitutes a neurodegenerative disorder. In addition, mounting evidence indicates that alterations in the gamma-aminobutyric acid neurotransmitter system are involved in ET pathophysiology. Here, we systematically review structural, functional, and metabolic neuroimaging studies and discuss current concepts of ET pathophysiology from an imaging perspective. Methods: We conducted a PubMed and Scopus search from 1966 up to December 2020, entering essential tremor in combination with any of the following search terms and their corresponding abbreviations: positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and gamma-aminobutyric acid (GABA). Results: Altered functional connectivity in the cerebellum and cerebello-thalamico-cortical circuitry is a prevalent finding in functional imaging studies. Reports from structural imaging studies are less consistent, and there is no clear evidence for cerebellar neurodegeneration. However, diffusion tensor imaging robustly points toward microstructural cerebellar changes. Radiotracer imaging suggests that the dopaminergic axis is largely preserved in ET. Similarly, measurements of nigral iron content and neuromelanin are unremarkable in most studies; this is in contrast to Parkinson's disease (PD). PET and MRS studies provide limited evidence for cerebellar and thalamic GABAergic dysfunction. Conclusions: There is robust evidence indicating that the cerebellum plays a key role within a multiple oscillator tremor network which underlies tremor genesis. However, whether cerebellar dysfunction relies on a neurodegenerative process remains unclear. Dopaminergic and iron imaging do not suggest a substantial overlap of ET with PD pathophysiology. There is limited evidence for alterations of the GABAergic neurotransmitter system in ET. The clinical, demographical, and genetic heterogeneity of ET translates into neuroimaging and likely explains the various inconsistencies reported.
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Affiliation(s)
- Florian Holtbernd
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Juelich GmbH, Juelich, Germany.,JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Juelich GmbH, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany.,Department of Neurology, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Juelich GmbH, Juelich, Germany.,JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Juelich GmbH, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany.,Department of Neurology, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
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16
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Lan H, Suo X, Li W, Li N, Li J, Peng J, Lei D, Sweeney JA, Kemp GJ, Peng R, Gong Q. Abnormalities of intrinsic brain activity in essential tremor: A meta-analysis of resting-state functional imaging. Hum Brain Mapp 2021; 42:3156-3167. [PMID: 33769638 PMCID: PMC8193520 DOI: 10.1002/hbm.25425] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 02/05/2023] Open
Abstract
Neuroimaging studies using a variety of techniques have demonstrated abnormal patterns of spontaneous brain activity in patients with essential tremor (ET). However, the findings are variable and inconsistent, hindering understanding of underlying neuropathology. We conducted a meta‐analysis of whole‐brain resting‐state functional neuroimaging studies in ET compared to healthy controls (HC), using anisotropic effect‐size seed‐based d mapping, to identify the most consistent brain activity alterations and their relation to clinical features. After systematic literature search, we included 13 studies reporting 14 comparisons, describing 286 ET patients and 254 HC. Subgroup analyses were conducted considering medication status, head tremor status, and methodological factors. Brain activity in ET is altered not only in the cerebellum and cerebral motor cortex, but also in nonmotor cortical regions including prefrontal cortex and insula. Most of the results remained unchanged in subgroup analyses of patients with head tremor, medication‐naive patients, studies with statistical threshold correction, and the large subgroup of studies using functional magnetic resonance imaging. These findings not only show consistent and robust abnormalities in specific brain regions but also provide new information on the biology of patient heterogeneity, and thus help to elucidate the pathophysiology of ET.
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Affiliation(s)
- Huan Lan
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China
| | - Xueling Suo
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China
| | - Wenbin Li
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China
| | - Nannan Li
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Junying Li
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Jiaxin Peng
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Du Lei
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China.,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - John A Sweeney
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China.,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Graham J Kemp
- Liverpool Magnetic Resonance Imaging Centre (LiMRIC) and Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Rong Peng
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Qiyong Gong
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China.,Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China
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17
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Ibrahim MF, Beevis JC, Empson RM. Essential Tremor - A Cerebellar Driven Disorder? Neuroscience 2020; 462:262-273. [PMID: 33212218 DOI: 10.1016/j.neuroscience.2020.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 10/23/2020] [Accepted: 11/01/2020] [Indexed: 02/07/2023]
Abstract
Abnormal tremors are the most common of all movement disorders. In this review we focus on the role of the cerebellum in Essential Tremor, a highly debilitating but poorly treated movement disorder. We propose a variety of mechanisms driving abnormal burst firing of deep cerebellar nuclei neurons as a key initiator of tremorgenesis in Essential Tremor. Targetting these mechanisms may generate more effective treatments for Essential Tremor.
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Affiliation(s)
- Mohamed Fasil Ibrahim
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand.
| | - Jessica C Beevis
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Ruth M Empson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
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18
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Cerebello-thalamo-cortical network is intrinsically altered in essential tremor: evidence from a resting state functional MRI study. Sci Rep 2020; 10:16661. [PMID: 33028912 PMCID: PMC7541442 DOI: 10.1038/s41598-020-73714-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 08/03/2020] [Indexed: 12/18/2022] Open
Abstract
Cerebello-thalamo-cortical network is suggested to be involved in the pathophysiology of Essential Tremor (ET). 23 patients with ET and 23 matched HC underwent a 3T-MRI with acquisition of a resting state sequence. Connectivity was investigated using a seed-based regression analyses approach. In ET patients were observed:Reduced connectivity between left primary motor cortex (M1) seed and right premotor cortex and cerebellum and bilateral premotor, parietal areas, supplementary motor area (SMA); Increased connectivity between left somatosensory cortex (S1) seed and parietal areas, M1, premotor cortex, SMA; reduced connectivity of this seed with cerebellum. Increased connectivity of SMA seed with premotor cortex and decreased with parietal and precentral areas; Increased connectivity between left thalamus seed and cerebellum; Reduced connectivity between right cerebellum seeds and other cerebellar areas, precentral and premotor areas. ET showed altered connectivity within the cortical sensory-motor network and between cerebral cortex and cerebellum. The increased connectivity between cerebellum and thalamus is consistent with their crucial role in tremor generation. These findings support the dynamical entrainment of multiple central oscillators throughout the cerebello-thalamo-cortical network in ET. This evidence is strengthened by the finding that this network is altered also when the core symptom is absent.
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19
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Boscolo Galazzo I, Magrinelli F, Pizzini FB, Storti SF, Agosta F, Filippi M, Marotta A, Mansueto G, Menegaz G, Tinazzi M. Voxel-based morphometry and task functional magnetic resonance imaging in essential tremor: evidence for a disrupted brain network. Sci Rep 2020; 10:15061. [PMID: 32934259 PMCID: PMC7493988 DOI: 10.1038/s41598-020-69514-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/13/2020] [Indexed: 11/09/2022] Open
Abstract
The pathophysiology of essential tremor (ET) is controversial and might be further elucidated by advanced neuroimaging. Focusing on homogenous ET patients diagnosed according to the 2018 consensus criteria, this study aimed to: (1) investigate whether task functional MRI (fMRI) can identify networks of activated and deactivated brain areas, (2) characterize morphometric and functional modulations, relative to healthy controls (HC). Ten ET patients and ten HC underwent fMRI while performing two motor tasks with their upper limb: (1) maintaining a posture (both groups); (2) simulating tremor (HC only). Activations/deactivations were obtained from General Linear Model and compared across groups/tasks. Voxel-based morphometry and linear regressions between clinical and fMRI data were also performed. Few cerebellar clusters of gray matter loss were found in ET. Conversely, widespread fMRI alterations were shown. Tremor in ET (task 1) was associated with extensive deactivations mainly involving the cerebellum, sensory-motor cortex, and basal ganglia compared to both tasks in HC, and was negatively correlated with clinical tremor scales. Homogeneous ET patients demonstrated deactivation patterns during tasks triggering tremor, encompassing a network of cortical and subcortical regions. Our results point towards a marked cerebellar involvement in ET pathophysiology and the presence of an impaired cerebello-thalamo-cortical tremor network.
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Affiliation(s)
- Ilaria Boscolo Galazzo
- Department of Computer Science, University of Verona, Strada Le Grazie 15, Ca' Vignal 2, 37134, Verona, Italy.
| | - Francesca Magrinelli
- Department of Neurosciences, Biomedicine and Movement Sciences, Neurology Section, University of Verona, Piazzale L.A. Scuro 10, 37134, Verona, Italy.
| | | | - Silvia Francesca Storti
- Department of Computer Science, University of Verona, Strada Le Grazie 15, Ca' Vignal 2, 37134, Verona, Italy
| | - Federica Agosta
- Neuroimaging Research Unit, Division of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Division of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Angela Marotta
- Department of Neurosciences, Biomedicine and Movement Sciences, Neurology Section, University of Verona, Piazzale L.A. Scuro 10, 37134, Verona, Italy
| | - Giancarlo Mansueto
- Department of Diagnostics and Pathology, University of Verona, Verona, Italy
| | - Gloria Menegaz
- Department of Computer Science, University of Verona, Strada Le Grazie 15, Ca' Vignal 2, 37134, Verona, Italy
| | - Michele Tinazzi
- Department of Neurosciences, Biomedicine and Movement Sciences, Neurology Section, University of Verona, Piazzale L.A. Scuro 10, 37134, Verona, Italy
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20
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Louis ED, Faust PL. Essential tremor: the most common form of cerebellar degeneration? CEREBELLUM & ATAXIAS 2020; 7:12. [PMID: 32922824 PMCID: PMC7427947 DOI: 10.1186/s40673-020-00121-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
Background The degenerative cerebellar ataxias comprise a large and heterogeneous group of neurological diseases whose hallmark clinical feature is ataxia, and which are accompanied, to variable degrees, by other features that are attributable to cerebellar dysfunction. Essential tremor (ET) is an exceptionally common neurological disease whose primary motor feature is action tremor, although patients often manifest intention tremor, mild gait ataxia and several other features of cerebellar dysfunction. Main Body In this paper, we review the abundant evidence derived from clinical, neuroimaging and postmortem studies, linking ET to cerebellar dysfunction. Furthermore, we review the combination of clinical, natural history and postmortem features suggesting that ET is neurodegenerative. We then compare the prevalence of ET (400 – 900 cases per 100,000) to that of the other cerebellar degenerations (ranging from <0.5 – 9 cases per 100,000, and in composite likely to be on the order of 20 cases per 100,000) and conclude that ET is 20 to 45 times more prevalent than all other forms of cerebellar degeneration combined. Conclusion Given the data we present, it is logical to conclude that ET is, by far, the most common form of cerebellar degeneration.
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Affiliation(s)
- Elan D Louis
- Department of Neurology and Therapeutics, University of Texas Southwestern, Dallas, TX USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY USA
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21
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Altered spontaneous brain activity in essential tremor with and without resting tremor: a resting-state fMRI study. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 34:201-212. [PMID: 32661843 DOI: 10.1007/s10334-020-00865-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/02/2020] [Accepted: 07/07/2020] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Essential tremor with resting tremor (rET) often exhibits severer clinical features and more extensive functional impairment than essential tremor without resting tremor (ETwr). However, the pathophysiology of rET is still unclear. This study aims to use resting-state functional magnetic resonance imaging (rs-fMRI) to explore the alterations of brain activity between the drug-naïve patients of rET and ETwr. METHODS We recruited 19 patients with rET, 31 patients with ETwr and 25 healthy controls (HCs) to undergo a 3.0-T rs-fMRI examination. The differences of regional brain spontaneous activity between the rET, ETwr and HCs, as well as between total ET (rET + ETwr) and HCs were measured by amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF). The relationships between the altered brain measurements and the clinical scores were analyzed. RESULTS Compared with HCs, both ET subgroups showed significantly decreased ALFF or fALFF values in the basal ganglia, inferior orbitofrontal gyrus and insula. The rET group specifically showed decreased ALFF values in the hippocampus and motor cortices, while the ETwr group specifically evidenced increased ALFF and fALFF values in the cerebellum. DISCUSSION Regional spontaneous activity in rET and ETwr share common changes and have differences, which may suggest that the functional activities in the limbic system and cerebellum are different between the two subtypes. Improved insights into rET and ETwr subtypes and the different brain spontaneous activity will be valuable for improving our understanding of the pathophysiology of the disease.
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22
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Human brain connectivity: Clinical applications for clinical neurophysiology. Clin Neurophysiol 2020; 131:1621-1651. [DOI: 10.1016/j.clinph.2020.03.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
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Brown AM, White JJ, van der Heijden ME, Zhou J, Lin T, Sillitoe RV. Purkinje cell misfiring generates high-amplitude action tremors that are corrected by cerebellar deep brain stimulation. eLife 2020; 9:e51928. [PMID: 32180549 PMCID: PMC7077982 DOI: 10.7554/elife.51928] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
Tremor is currently ranked as the most common movement disorder. The brain regions and neural signals that initiate the debilitating shakiness of different body parts remain unclear. Here, we found that genetically silencing cerebellar Purkinje cell output blocked tremor in mice that were given the tremorgenic drug harmaline. We show in awake behaving mice that the onset of tremor is coincident with rhythmic Purkinje cell firing, which alters the activity of their target cerebellar nuclei cells. We mimic the tremorgenic action of the drug with optogenetics and present evidence that highly patterned Purkinje cell activity drives a powerful tremor in otherwise normal mice. Modulating the altered activity with deep brain stimulation directed to the Purkinje cell output in the cerebellar nuclei reduced tremor in freely moving mice. Together, the data implicate Purkinje cell connectivity as a neural substrate for tremor and a gateway for signals that mediate the disease.
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Affiliation(s)
- Amanda M Brown
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Joshua J White
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Meike E van der Heijden
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Joy Zhou
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute of Texas Children's HospitalHoustonUnited States
- Development, Disease Models & Therapeutics Graduate Program, Baylor College of MedicineHoustonUnited States
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DeSimone JC, Archer DB, Vaillancourt DE, Wagle Shukla A. Network-level connectivity is a critical feature distinguishing dystonic tremor and essential tremor. Brain 2020; 142:1644-1659. [PMID: 30957839 DOI: 10.1093/brain/awz085] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/04/2019] [Accepted: 02/06/2019] [Indexed: 11/12/2022] Open
Abstract
Dystonia is a movement disorder characterized by involuntary muscle co-contractions that give rise to disabling movements and postures. A recent expert consensus labelled the incidence of tremor as a core feature of dystonia that can affect body regions both symptomatic and asymptomatic to dystonic features. We are only beginning to understand the neural network-level signatures that relate to clinical features of dystonic tremor. At the same time, clinical features of dystonic tremor can resemble that of essential tremor and present a diagnostic confound for clinicians. Here, we examined network-level functional activation and connectivity in patients with dystonic tremor and essential tremor. The dystonic tremor group included primarily cervical dystonia patients with dystonic head tremor and the majority had additional upper-limb tremor. The experimental paradigm included a precision grip-force task wherein online visual feedback related to force was manipulated across high and low spatial feedback levels. Prior work using this paradigm in essential tremor patients produced exacerbation of grip-force tremor and associated changes in functional activation. As such, we directly compared the effect of visual feedback on grip-force tremor and associated functional network-level activation and connectivity between dystonic tremor and essential tremor patient cohorts to better understand disease-specific mechanisms. Increased visual feedback similarly exacerbated force tremor during the grip-force task in dystonic tremor and essential tremor cohorts. Patients with dystonic tremor and essential tremor were characterized by distinct functional activation abnormalities in cortical regions but not in the cerebellum. We examined seed-based functional connectivity from the sensorimotor cortex, globus pallidus internus, ventral intermediate thalamic nucleus, and dentate nucleus, and observed abnormal functional connectivity networks in dystonic tremor and essential tremor groups relative to controls. However, the effects were far more widespread in the dystonic tremor group as changes in functional connectivity were revealed across cortical, subcortical, and cerebellar regions independent of the seed location. A unique pattern for dystonic tremor included widespread reductions in functional connectivity compared to essential tremor within higher-level cortical, basal ganglia, and cerebellar regions. Importantly, a receiver operating characteristic determined that functional connectivity z-scores were able to classify dystonic tremor and essential tremor with 89% area under the curve, whereas combining functional connectivity with force tremor yielded 94%. These findings point to network-level connectivity as an important feature that differs substantially between dystonic tremor and essential tremor and should be further explored in implementing appropriate diagnostic and therapeutic strategies.
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Affiliation(s)
- Jesse C DeSimone
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Derek B Archer
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.,Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.,Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Aparna Wagle Shukla
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.,Fixel Center for Neurological Disease, College of Medicine, University of Florida, Gainesville, FL, USA
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25
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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.
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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
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26
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Lee J, Jo HJ, Kim I, Lee J, Min HK, In MH, Knight EJ, Chang SY. Mapping BOLD Activation by Pharmacologically Evoked Tremor in Swine. Front Neurosci 2019; 13:985. [PMID: 31619955 PMCID: PMC6759958 DOI: 10.3389/fnins.2019.00985] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/02/2019] [Indexed: 11/26/2022] Open
Abstract
Harmaline-induced tremor is one of the most commonly utilized disease models for essential tremor (ET). However, the underlying neural networks involved in harmaline-induced tremor and the degree to which these are a representative model of the pathophysiologic mechanism of ET are incompletely understood. In this study, we evaluated the functional brain network effects induced by systemic injection of harmaline using pharmacological functional magnetic resonance imaging (ph-fMRI) in the swine model. With harmaline administration, we observed significant activation changes in cerebellum, thalamus, and inferior olivary nucleus (ION). In addition, inter-regional correlations in activity between cerebellum and deep cerebellar nuclei and between cerebellum and thalamus were significantly enhanced. These harmaline-induced effects gradually decreased with repeated administration of drug, replicating the previously demonstrated ‘tolerance’ effect. This study demonstrates that harmaline-induced tremor is associated with activity changes in brain regions previously implicated in humans with ET. Thus, harmaline-induction of tremor in the swine may be a useful model to explore the neurological effects of novel therapeutic agents and/or neuromodulation techniques for ET.
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Affiliation(s)
- Jeyeon Lee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
| | - Hang Joon Jo
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States.,Department of Radiology, Mayo Clinic, Rochester, MN, United States.,Department of Neurology, Mayo Clinic, Rochester, MN, United States.,Department of Physiology, College of Medicine, Hanyang University, Seoul, South Korea
| | - Inyong Kim
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Jihyun Lee
- Laboratory of Brain and Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Anyang, South Korea
| | - Hoon-Ki Min
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Myung-Ho In
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Emily J Knight
- Department of Developmental Behavioral Pediatrics, University of Rochester, Rochester, NY, United States
| | - Su-Youne Chang
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
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27
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The cortico-rubral and cerebello-rubral pathways are topographically organized within the human red nucleus. Sci Rep 2019; 9:12117. [PMID: 31431648 PMCID: PMC6702172 DOI: 10.1038/s41598-019-48164-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/11/2019] [Indexed: 02/03/2023] Open
Abstract
The Red Nucleus (RN) is a large nucleus located in the ventral midbrain: it is subdivided into a small caudal magnocellular part (mRN) and a large rostral parvocellular part (pRN). These distinct structural regions are part of functionally different networks and show distinctive connectivity features: the mRN is connected to the interposed nucleus, whilst the pRN is mainly connected to dentate nucleus, cortex and inferior olivary complex. Despite functional neuroimaging studies suggest RN involvement in complex motor and higher order functions, the pRN and mRN cannot be distinguished using conventional MRI. Herein, we employ high-quality structural and diffusion MRI data of 100 individuals from the Human Connectome Project repository and constrained spherical deconvolution tractography to perform connectivity-based segmentation of the human RN. In particular, we tracked connections of RN with the inferior olivary complex, the interposed nucleus, the dentate nucleus and the cerebral cortex. We found that the RN can be subdivided according to its connectivity into two clusters: a large ventrolateral one, mainly connected with the cerebral cortex and the inferior olivary complex, and a smaller dorsomedial one, mainly connected with the interposed nucleus. This structural topography strongly reflects the connectivity patterns of pRN and mRN respectively. Structural connectivity-based segmentation could represent a useful tool for the identification of distinct subregions of the human red nucleus on 3T MRI thus allowing a better evaluation of this subcortical structure in healthy and pathological conditions.
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28
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Role of cerebellar GABAergic dysfunctions in the origins of essential tremor. Proc Natl Acad Sci U S A 2019; 116:13592-13601. [PMID: 31209041 DOI: 10.1073/pnas.1817689116] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Essential tremor (ET) is among the most prevalent movement disorders, but its origins are elusive. The inferior olivary nucleus (ION) has been hypothesized as the prime generator of tremor because of the pacemaker properties of ION neurons, but structural and functional changes in ION are unlikely under ET. Abnormalities have instead been reported in the cerebello-thalamo-cortical network, including dysfunctions of the GABAergic projections from the cerebellar cortex to the dentate nucleus. It remains unclear, though, how tremor would relate to a dysfunction of cerebellar connectivity. To address this question, we built a computational model of the cortico-cerebello-thalamo-cortical loop. We simulated the effects of a progressive loss of GABAA α1-receptor subunits and up-regulation of α2/3-receptor subunits in the dentate nucleus, and correspondingly, we studied the evolution of the firing patterns along the loop. The model closely reproduced experimental evidence for each structure in the loop. It showed that an alteration of amplitudes and decay times of the GABAergic currents to the dentate nucleus can facilitate sustained oscillatory activity at tremor frequency throughout the network as well as a robust bursting activity in the thalamus, which is consistent with observations of thalamic tremor cells in ET patients. Tremor-related oscillations initiated in small neural populations and spread to a larger network as the synaptic dysfunction increased, while thalamic high-frequency stimulation suppressed tremor-related activity in thalamus but increased the oscillation frequency in the olivocerebellar loop. These results suggest a mechanism for tremor generation under cerebellar dysfunction, which may explain the origin of ET.
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29
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Abstract
Even before the success of combined positron emission tomography and computed tomography (PET/CT), the neuroimaging community was conceiving the idea to integrate the positron emission tomography (PET), with very high molecular quantitative data but low spatial resolution, and magnetic resonance imaging (MRI), with high spatial resolution. Several technical limitations have delayed the use of a hybrid scanner in neuroimaging studies, including the full integration of the PET detector ring within the MRI system, the optimization of data acquisition, and the implementation of reliable methods for PET attenuation, motion correction, and joint image reconstruction. To be valid and useful in clinical and research settings, this instrument should be able to simultaneously acquire PET and MRI, and generate quantitative parametric PET images comparable to PET-CT. While post hoc co-registration of combined PET and MRI data acquired separately became the most reliable technique for the generation of "fused" PET-MRI images, only hybrid PET-MRI approach allows merging these measurements naturally and correlating them in a temporal manner. Furthermore, hybrid PET-MRI represents the most accurate tool to investigate in vivo the interplay between molecular and functional aspects of brain pathophysiology. Hybrid PET-MRI technology is still in the early stages in the movement disorders field, due to the limited availability of scanners with integrated optimized methodological models. This technology is ideally suited to investigate interactions between resting-state functional/arterial spin labeling MRI and [18F]FDG PET glucose metabolism in the evaluation of the brain "hubs" particularly vulnerable to neurodegeneration, areas with a high degree of connectivity and associated with an efficient synaptic neurotransmission. In Parkinson's disease, hybrid PET-MRI is also the ideal instrument to deeper explore the relationship between resting-state functional MRI and dopamine release at [11C]raclopride PET challenge, in the identification of early drug-naïve Parkinson's disease patients at higher risk of motor complications and in the evaluation of the efficacy of novel neuroprotective treatment able to restore at the same time the altered resting state and the release of dopamine. In this chapter, we discuss the key methodological aspects of hybrid PET-MRI; the evidence in movement disorders of the key resting-state functional and perfusion MRI; [18F]FDG PET and [11C]raclopride PET challenge studies; the potential advantages of using hybrid PET-MRI to investigate the pathophysiology of movement disorders and neurodegenerative diseases. Future directions of hybrid PET-MRI will be discussed alongside with up-to-date technological innovations on hybrid systems.
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30
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Roy A, Coombes SA, Chung JW, Archer DB, Okun MS, Hess CW, Wagle Shukla A, Vaillancourt DE. Cortical dynamics within and between parietal and motor cortex in essential tremor. Mov Disord 2018; 34:95-104. [PMID: 30345712 DOI: 10.1002/mds.27522] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/08/2018] [Accepted: 09/12/2018] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Evidence from functional imaging in essential tremor suggests that activity within parietal and motor cortices may be associated with worsening of tremor at increased visual feedback. OBJECTIVES Examine how cortical oscillations within these regions and the connectivity between these regions is associated with worsening of tremor in essential tremor in response to high visual feedback. METHOD The study included 24 essential tremor participants and 17 controls. We measured cortical activity and tremor magnitude at low and high feedback conditions. Cortical activity was measured using high-density electroencephalogram and isolated using source localization. RESULTS Changes in power across feedback in the 4-12 Hz and 12-30 Hz bands were reduced within the contralateral motor cortex of essential tremor patients compared to controls. The 12-30 Hz bidirectional connectivity between the parietal and contralateral motor cortex was decreased in essential tremor patients. Worsening of tremor from low to high visual feedback was associated with 4-12 Hz activity in contralateral motor cortex. The greatest separation between groups was found when using the difference of the contralateral motor cortex activity at high and low feedback, rather than either feedback condition alone. CONCLUSION Our findings provide new evidence that tremor in essential tremor is associated with reduced power across feedback in the motor cortex and reduced connectivity between the parietal and motor cortices. Combined with previous work on the cerebellar-thalamo-cortical motor circuit, our findings suggest that the network level disturbances associated with essential tremor extend to the cortico-cortical pathway between the parietal cortex and motor cortex. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Arnab Roy
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Stephen A Coombes
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Jae Woo Chung
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Derek B Archer
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Michael S Okun
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - Christopher W Hess
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - Aparna Wagle Shukla
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA.,Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA.,Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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31
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Wang P, Luo X, Zhong C, Yang L, Guo F, Yu N. Resting state fMRI reveals the altered synchronization of BOLD signals in essential tremor. J Neurol Sci 2018; 392:69-76. [PMID: 30025236 DOI: 10.1016/j.jns.2018.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 06/14/2018] [Accepted: 07/08/2018] [Indexed: 10/28/2022]
Abstract
Essential tremor (ET) is one of the most common movement disorders in humans. Nevertheless, there remain several controversies surrounding ET, such as whether it is a disorder of abnormal neuronal oscillations within the tremor network. In this work, the resting-state fMRI data were collected from 17 ET patients and 17 age- and gender-matched healthy controls. First, using FOur-dimensional (spatiotemporal) Consistency of local neural Activities (FOCA) the abnormal synchronization of fMRI signals in ET patients were investigated. Then, global functional connectivity intensity (gFCI) and density (gFCD) were analyzed in the regions exhibiting significant FOCA differences. Compared with healthy controls, patients with ET showed the increased FOCA values found in the bilateral cuneus, the left lingual gyrus, the left paracentral lobule, the right middle temporal gyrus, the bilateral precentral gyrus, the right postcentral gyrus, the pallidum and putamen. Decreased FOCA values in ET patients were located in the frontal gyrus, the bilateral anterior cingulate and the medial dorsal nucleus of right thalamus. In ET patients, significant changes in gFCI and gFCD were located in the cuneus, the middle temporal gyrus and the middle frontal gyrus. Changes in gFCI were also found in the medial frontal gyrus and thalamus in addition to changes in gFCD in the precentral gyrus. Our results provided further evidence that ET might present with abnormal spontaneous activity in the tremor network, including motor-related cotex, basal ganglia and thalamus, as well as distributed non-motor areas. This work also demonstrated that FOCA and functional connectivity have the potential to provide important insight into the pathophysiological mechanism of ET.
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Affiliation(s)
- Pu Wang
- Department of Neurology, Chongzhou People's Hospital, Chongzhou, Sichuan, China
| | - Xiangdong Luo
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Chengqing Zhong
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Lili Yang
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Fuqiang Guo
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.
| | - Nengwei Yu
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.
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32
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Boonstra FMC, Perera T, Noffs G, Marotta C, Vogel AP, Evans AH, Butzkueven H, Moffat BA, van der Walt A, Kolbe SC. Novel Functional MRI Task for Studying the Neural Correlates of Upper Limb Tremor. Front Neurol 2018; 9:513. [PMID: 30013508 PMCID: PMC6036145 DOI: 10.3389/fneur.2018.00513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/11/2018] [Indexed: 01/06/2023] Open
Abstract
Introduction: Tremor of the upper limbs is a disabling symptom that is present during several neurological disorders and is currently without treatment. Functional MRI (fMRI) is an essential tool to investigate the pathophysiology of tremor and aid the development of treatment options. However, no adequately or standardized protocols for fMRI exists at present. Here we present a novel, online available fMRI task that could be used to assess the in vivo pathology of tremor. Objective: This study aims to validate the tremor-evoking potential of the fMRI task in a small group of tremor patients outside the scanner and assess the reproducibility of the fMRI task related activation in healthy controls. Methods: Twelve HCs were scanned at two time points (baseline and after 6-weeks). There were two runs of multi-band fMRI and the tasks included a “brick-breaker” joystick game. The game consisted of three conditions designed to control for most of the activation related to performing the task by contrasting the conditions: WATCH (look at the game without moving joystick), MOVE (rhythmic left/right movement of joystick without game), and PLAY (playing the game). Task fMRI was analyzed using FSL FEAT to determine clusters of activation during the different conditions. Maximum activation within the clusters was used to assess the ability to control for task related activation and reproducibility. Four tremor patients have been included to test ecological and construct validity of the joystick task by assessing tremor frequencies captured by the joystick. Results: In HCs the game activated areas corresponding to motor, attention and visual areas. Most areas of activation by our game showed moderate to good reproducibility (intraclass correlation coefficient (ICC) 0.531–0.906) with only inferior parietal lobe activation showing poor reproducibility (ICC 0.446). Furthermore, the joystick captured significantly more tremulous movement in tremor patients compared to HCs (p = 0.01) during PLAY, but not during MOVE. Conclusion: Validation of our novel task confirmed tremor-evoking potential and reproducibility analyses yielded acceptable results to continue further investigations into the pathophysiology of tremor. The use of this technique in studies with tremor patient will no doubt provide significant insights into the treatment options.
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Affiliation(s)
| | - Thushara Perera
- The Bionics Institute, East Melbourne, VIC, Australia.,Department of Medical Bionics, University of Melbourne, Melbourne, VIC, Australia
| | - Gustavo Noffs
- Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Centre for Neuroscience of Speech, University of Melbourne, Melbourne, VIC, Australia
| | - Cassandra Marotta
- Centre for Neuroscience of Speech, University of Melbourne, Melbourne, VIC, Australia.,Redenlab, Melbourne, VIC, Australia
| | - Adam P Vogel
- The Bionics Institute, East Melbourne, VIC, Australia.,Centre for Neuroscience of Speech, University of Melbourne, Melbourne, VIC, Australia.,Redenlab, Melbourne, VIC, Australia.,Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Andrew H Evans
- Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Helmut Butzkueven
- Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Department of Medicine, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Clayton, VIC, Australia
| | - Bradford A Moffat
- Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - Anneke van der Walt
- Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Department of Medicine, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Clayton, VIC, Australia
| | - Scott C Kolbe
- Department of Medicine, University of Melbourne, Melbourne, VIC, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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33
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Tuleasca C, Najdenovska E, Régis J, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Bach Cuadra M, Levivier M, Van De Ville D. Pretherapeutic functional neuroimaging predicts tremor arrest after thalamotomy. Acta Neurol Scand 2018; 137:500-508. [PMID: 29315459 DOI: 10.1111/ane.12891] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2017] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Essential tremor (ET) represents the most common movement disorder. Drug-resistant ET can benefit from standard stereotactic procedures (deep brain stimulation or radiofrequency thalamotomy) or alternatively minimally invasive high-focused ultrasound or radiosurgery. All aim at same target, thalamic ventro-intermediate nucleus (Vim). METHODS The study included a cohort of 17 consecutive patients, with ET, treated only with left unilateral stereotactic radiosurgical thalamotomy (SRS-T) between September 2014 and August 2015. The mean time to tremor improvement was 3.32 months (SD 2.7, 0.5-10). Neuroimaging data were collected at baseline (n = 17). Standard tremor scores, including activities of daily living (ADL) and tremor score on treated hand (TSTH), were completed pretherapeutically and 1 year later. We further correlate these scores with baseline inter-connectivity in twenty major large-scale brain networks. RESULTS We report as predictive three networks, with the interconnected statistically significant clusters: primary motor cortex interconnected with inferior olivary nucleus, bilateral thalamus interconnected with motor cerebellum lobule V2 (ADL), and anterior default-mode network interconnected with Brodmann area 103 (TSTH). For all, more positive pretherapeutic interconnectivity correlated with higher drop in points on the respective scores. Age, disease duration, or time-to-response after SRS-T were not statistically correlated with pretherapeutic brain connectivity measures (P > .05). The same applied to pretherapeutic tremor scores, after using the same methodology described above. CONCLUSIONS Our findings have clinical implications for predicting clinical response after SRS-T. Here, using pretherapeutic magnetic resonance imaging and data processing without prior hypothesis, we show that pretherapeutic network(s) interconnectivity strength predicts tremor arrest in drug-naïve ET, following stereotactic radiosurgical thalamotomy.
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Affiliation(s)
- C. Tuleasca
- Neurosurgery Service and Gamma Knife Center; Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - E. Najdenovska
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
| | - J. Régis
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit; CHU Timone; Marseille France
| | - T. Witjas
- Neurology Department; CHU Timone; Marseille France
| | - N. Girard
- AMU, CRMBM UMR CNRS 7339; Faculté de Médecine et APHM; Department of Diagnostic and Interventionnal Neuroradiology; Hopital Timone; Marseille France
| | - J. Champoudry
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit; CHU Timone; Marseille France
| | - M. Faouzi
- Center for Clinical Epidemiology; Institute of Social and Preventive Medicine; Lausanne Switzerland
| | - J.-P. Thiran
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
- Department of Radiology; Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
| | - M. Bach Cuadra
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - M. Levivier
- Neurosurgery Service and Gamma Knife Center; Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - D. Van De Ville
- Faculty of Medicine; University of Geneva; Geneva Switzerland
- Medical Image Processing Laboratory; Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
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Muthuraman M, Raethjen J, Koirala N, Anwar AR, Mideksa KG, Elble R, Groppa S, Deuschl G. Cerebello-cortical network fingerprints differ between essential, Parkinson’s and mimicked tremors. Brain 2018; 141:1770-1781. [DOI: 10.1093/brain/awy098] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/13/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Muthuraman Muthuraman
- Section of Movement Disorders and Neurostimulation, Biomedical Statistics and Multimodal Signal processing unit, Department of Neurology, Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz-55131, Germany
| | - Jan Raethjen
- Department of Neurology, Christian-Albrechts-University, Kiel-24105, Germany
| | - Nabin Koirala
- Section of Movement Disorders and Neurostimulation, Biomedical Statistics and Multimodal Signal processing unit, Department of Neurology, Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz-55131, Germany
| | - Abdul Rauf Anwar
- Department of Neurology, Christian-Albrechts-University, Kiel-24105, Germany
- Biomedical Engineering Centre, University of Engineering & Technology, Lahore (KSK Campus)-54890, Pakistan
| | - Kidist G Mideksa
- Department of Neurology, Christian-Albrechts-University, Kiel-24105, Germany
- Institute for Circuit and System Theory, Christian-Albrechts-University, Kiel-24143, Germany
| | - Rodger Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, 62794-9643, USA
| | - Sergiu Groppa
- Section of Movement Disorders and Neurostimulation, Biomedical Statistics and Multimodal Signal processing unit, Department of Neurology, Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz-55131, Germany
| | - Günter Deuschl
- Department of Neurology, Christian-Albrechts-University, Kiel-24105, Germany
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Moldovan AS, Hartmann CJ, Trenado C, Meumertzheim N, Slotty PJ, Vesper J, Schnitzler A, Groiss SJ. Less is more - Pulse width dependent therapeutic window in deep brain stimulation for essential tremor. Brain Stimul 2018; 11:1132-1139. [PMID: 29735344 DOI: 10.1016/j.brs.2018.04.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/23/2018] [Accepted: 04/24/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Shorter pulse widths than conventional pulse width settings may lead to reduction of side effects and therefore be a valuable therapeutic option for deep brain stimulation (DBS) in patients with essential tremor (ET). OBJECTIVE To compare the DBS effect of shorter pulse width at 40 μs (DBS-40 μs) to conventional pulse width at 60 μs (DBS-60 μs) on the therapeutic window in ET patients. METHODS For this prospective, randomized, double-blind, crossover study 9 ET patients with chronic DBS of the ventral intermediate nucleus (VIM)/posterior subthalamic area (PSA) were recruited. Therapeutic window was calculated by determining efficacy and side effect thresholds for DBS-40 μs and DBS-60 μs. Tremor Rating Scales and Kinesia tremor analyses were used to compare clinical efficacy between the considered settings and deactivated DBS (DBS-OFF). Volume of neural activation (VNA) was calculated for both efficacy and side effect thresholds at each pulse width. RESULTS DBS-40 μs showed a significantly larger therapeutic window than DBS-60 μs mainly due to higher side-effect thresholds. Both conditions significantly improved tremor compared to DBS-OFF, while efficacy was comparable between DBS-40 μs and DBS-60 μs. Moreover, VNA at efficacy threshold was smaller and less energy was required for tremor suppression with DBS-40 μs compared to DBS-60 μs. CONCLUSIONS VIM/PSA-DBS with short pulse width represents a promising programming option for DBS in ET as it reduces side effects while maintaining efficient tremor suppression. Furthermore, our data support the notion of pulse width dependent selective modulation of distinct fiber tracts leading to widening of the therapeutic window.
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Affiliation(s)
- Alexia-Sabine Moldovan
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Christian Johannes Hartmann
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Carlos Trenado
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Department of Psychology and Neurosciences, Translational Neuromodulation Unit, Leibniz Centre for Working Environment and Human Factors, TU Dortmund, Dortmund, Germany
| | - Nicola Meumertzheim
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Philipp Jörg Slotty
- Department of Functional and Stereotactic Neurosurgery, Center for Neuromodulation, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Jan Vesper
- Department of Functional and Stereotactic Neurosurgery, Center for Neuromodulation, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Alfons Schnitzler
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Stefan Jun Groiss
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany.
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Liu C, Wang J, Hou Y, Qi Z, Wang L, Zhan S, Wang R, Wang Y. Mapping the changed hubs and corresponding functional connectivity in idiopathic restless legs syndrome. Sleep Med 2018; 45:132-139. [PMID: 29680421 DOI: 10.1016/j.sleep.2017.12.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/19/2017] [Accepted: 12/30/2017] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The hubs of the brain network play a key role in integrating and transferring information between different functional modules. However, whether the changed pattern in functional network hubs contributes to the onset of leg discomfort symptoms in restless legs syndrome (RLS) patients remains unclear. Using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory methods, we investigated whether alterations of hubs can be detected in RLS. METHODS First, we constructed the whole-brain voxelwise functional connectivity and calculated a functional connectivity strength (FCS) map in each of 16 drug-naive idiopathic RLS patients and 26 gender- and age-matched healthy control (HC) subjects. Next, a two-sample t test was applied to compare the FCS maps between HC and RLS patients, and to identify significant changes in FCS in RLS patients. To further elucidate the corresponding changes in the functional connectivity patterns of the aberrant hubs in RLS patients, whole-brain resting-state functional connectivity analyses for the hub areas were performed. RESULTS The hub analysis revealed decreased FCS in the cuneus, fusiform gyrus, paracentral lobe, and precuneus, and increased FCS in the superior frontal gyrus and thalamus in idiopathic drug-naive RLS patients. Subsequent functional connectivity analyses revealed decreased functional connectivity in sensorimotor and visual processing networks and increased functional connectivity in the affective cognitive network and cerebellar-thalamic circuit. Furthermore, the mean FCS value in the superior frontal gyrus was significantly correlated with Hamilton Anxiety Rating Scale scores in RLS patients, and the mean FCS value in the fusiform gyrus was significantly correlated with Hamilton Depression Rating Scale scores. CONCLUSIONS These findings may provide novel insight into the pathophysiology of RLS.
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Affiliation(s)
- Chunyan Liu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Jiaojian Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China
| | - Yue Hou
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Zhigang Qi
- Department of Radiology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Li Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Shuqin Zhan
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Rong Wang
- Central Laboratory, Xuan Wu Hospital, Capital Medical University, Beijing Institute for Brain Disorders, Center of Alzheimer's Disease, Beijing, China; Beijing Geriatric Medical Research Center, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing, China.
| | - Yuping Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neuromodulation, Beijing, China.
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37
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Boonstra F, Florescu G, Evans A, Steward C, Mitchell P, Desmond P, Moffat B, Butzkueven H, Kolbe S, van der Walt A. Tremor in multiple sclerosis is associated with cerebello-thalamic pathology. J Neural Transm (Vienna) 2017; 124:1509-1514. [PMID: 29098451 PMCID: PMC5686246 DOI: 10.1007/s00702-017-1798-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/13/2017] [Indexed: 01/21/2023]
Abstract
Tremor in people with multiple sclerosis (MS) is a frequent and debilitating symptom with a relatively poorly understood pathophysiology. To determine the relationship between clinical tremor severity and structural magnetic resonance imaging parameters. Eleven patients with clinically definite MS and right-sided upper limb tremor were studied. Tremor severity was assessed using the Bain score (overall severity, writing, and Archimedes spiral drawing). Cerebellar dysfunction was assessed using the Scale for the Assessment and Rating of Ataxia. Dystonia was assessed using the Global Dystonia Scale adapted for upper limb. For all subjects, volume was calculated for the thalamus from T1-weighted volumetric scans using Freesurfer. Superior cerebellar peduncle (SCP) cross-sectional areas were measured manually. The presence of lesions was visually determined and the lesion volumes were calculated by the lesion growth algorithm as implemented in the Lesion Segmentation Toolbox. Right thalamic volume negatively correlated with Bain tremor severity score (ρ = - 0.65, p = 0.03). Left thalamic volume negatively correlated with general Bain tremor severity score (ρ = - 0.65, p = 0.03) and the Bain writing score (ρ = - 0.65, p = 0.03). Right SCP area negatively correlated with Bain writing score (ρ = - 0.69, p = 0.02). Finally, Bain Archimedes score was significantly higher in patients with lesions in the contralateral thalamus. Whole brain lesion load showed no relationship with tremor severity. These results implicate degeneration of key structures within the cerebello-thalamic pathway as pathological substrates for tremor in MS patients.
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Affiliation(s)
- Frederique Boonstra
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Australia
| | - Grace Florescu
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Andrew Evans
- Department of Neurology, The Royal Melbourne Hospital, Level 4 South, 300 Grattan Street, Parkville, VIC, 3052, Australia
| | - Chris Steward
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
- Department of Medicine, Royal Melbourne Hospital, Melbourne, Australia
| | - Peter Mitchell
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Patricia Desmond
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Brad Moffat
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Australia
| | - Helmut Butzkueven
- Department of Neurology, The Royal Melbourne Hospital, Level 4 South, 300 Grattan Street, Parkville, VIC, 3052, Australia
- Melbourne Brain Centre at Royal Melbourne Hospital, Department of Medicine, University of Melbourne, Melbourne, Australia
- Multiple Sclerosis Unit, Box Hill Hospital, Box Hill, Australia
- Department of Neuroscience, Alfred Central Clinical School, Monash University, Melbourne, Australia
| | - Scott Kolbe
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Australia
| | - Anneke van der Walt
- Department of Neurology, The Royal Melbourne Hospital, Level 4 South, 300 Grattan Street, Parkville, VIC, 3052, Australia.
- Melbourne Brain Centre at Royal Melbourne Hospital, Department of Medicine, University of Melbourne, Melbourne, Australia.
- Department of Neuroscience, Alfred Central Clinical School, Monash University, Melbourne, Australia.
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Park HJ, Pae C, Friston K, Jang C, Razi A, Zeidman P, Chang WS, Chang JW. Hierarchical Dynamic Causal Modeling of Resting-State fMRI Reveals Longitudinal Changes in Effective Connectivity in the Motor System after Thalamotomy for Essential Tremor. Front Neurol 2017; 8:346. [PMID: 28775707 PMCID: PMC5517411 DOI: 10.3389/fneur.2017.00346] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/03/2017] [Indexed: 01/10/2023] Open
Abstract
Thalamotomy at the ventralis intermedius nucleus for essential tremor is known to cause changes in motor circuitry, but how a focal lesion leads to progressive changes in connectivity is not clear. To understand the mechanisms by which thalamotomy exerts enduring effects on motor circuitry, a quantitative analysis of directed or effective connectivity among motor-related areas is required. We characterized changes in effective connectivity of the motor system following thalamotomy using (spectral) dynamic causal modeling (spDCM) for resting-state fMRI. To differentiate long-lasting treatment effects from transient effects, and to identify symptom-related changes in effective connectivity, we subject longitudinal resting-state fMRI data to spDCM, acquired 1 day prior to, and 1 day, 7 days, and 3 months after thalamotomy using a non-cranium-opening MRI-guided focused ultrasound ablation technique. For the group-level (between subject) analysis of longitudinal (between-session) effects, we introduce a multilevel parametric empirical Bayes (PEB) analysis for spDCM. We found remarkably selective and consistent changes in effective connectivity from the ventrolateral nuclei and the supplementary motor area to the contralateral dentate nucleus after thalamotomy, which may be mediated via a polysynaptic thalamic-cortical-cerebellar motor loop. Crucially, changes in effective connectivity predicted changes in clinical motor-symptom scores after thalamotomy. This study speaks to the efficacy of thalamotomy in regulating the dentate nucleus in the context of treating essential tremor. Furthermore, it illustrates the utility of PEB for group-level analysis of dynamic causal modeling in quantifying longitudinal changes in effective connectivity; i.e., measuring long-term plasticity in human subjects non-invasively.
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Affiliation(s)
- Hae-Jeong Park
- BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea.,Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.,Center for Systems Brain Sciences, Institute of Human Complexity and Systems Science, Yonsei University, Seoul, South Korea.,Department of Cognitive Science, Yonsei University, Seoul, South Korea
| | - Chongwon Pae
- BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Karl Friston
- The Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom
| | - Changwon Jang
- BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Adeel Razi
- The Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom.,Monash Institute of Cognitive and Clinical Neurosciences, Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia.,Department of Electronic Engineering, NED University of Engineering and Technology, Karachi, Pakistan
| | - Peter Zeidman
- The Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom
| | - Won Seok Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, South Korea
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Schöberl F, Feil K, Xiong G, Bartenstein P, la Fougére C, Jahn K, Brandt T, Strupp M, Dieterich M, Zwergal A. Pathological ponto-cerebello-thalamo-cortical activations in primary orthostatic tremor during lying and stance. Brain 2017; 140:83-97. [PMID: 28031220 DOI: 10.1093/brain/aww268] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/25/2016] [Accepted: 09/07/2016] [Indexed: 11/14/2022] Open
Abstract
Primary orthostatic tremor is a rare neurological disease characterized mainly by a high frequency tremor of the legs while standing. The aim of this study was to identify the common core structures of the oscillatory circuit in orthostatic tremor and how it is modulated by changes of body position. Ten patients with orthostatic tremor and 10 healthy age-matched control subjects underwent a standardized neurological and neuro-ophthalmological examination including electromyographic and posturographic recordings. Task-dependent changes of cerebral glucose metabolism during lying and standing were measured in all subjects by sequential 18F-fluorodeoxyglucose-positron emission tomography on separate days. Results were compared between groups and conditions. All the orthostatic tremor patients, but no control subject, showed the characteristic 13-18 Hz tremor in coherent muscles during standing, which ceased in the supine position. While lying, patients had a significantly increased regional cerebral glucose metabolism in the pontine tegmentum, the posterior cerebellum (including the dentate nuclei), the ventral intermediate and ventral posterolateral nucleus of the thalamus, and the primary motor cortex bilaterally compared to controls. Similar glucose metabolism changes occurred with clinical manifestation of the tremor during standing. The glucose metabolism was relatively decreased in mesiofrontal cortical areas (i.e. the medial prefrontal cortex, supplementary motor area and anterior cingulate cortex) and the bilateral anterior insula in orthostatic tremor patients while lying and standing. The mesiofrontal hypometabolism correlated with increased body sway in posturography. This study confirms and further elucidates ponto-cerebello-thalamo-primary motor cortical activations underlying primary orthostatic tremor, which presented consistently in a group of patients. Compared to other tremor disorders one characteristic feature in orthostatic tremor seems to be the involvement of the pontine tegmentum in the pathophysiology of tremor generation. High frequency oscillatory properties of pontine tegmental neurons have been reported in pathological oscillatory eye movements. It is remarkable that the characteristic activation and deactivation pattern in orthostatic tremor is already present in the supine position without tremor presentation. Multilevel changes of neuronal excitability during upright stance may trigger activation of the orthostatic tremor network. Based on the functional imaging data described in this study, it is hypothesized that a mesiofrontal deactivation is another characteristic feature of orthostatic tremor and plays a pivotal role in development of postural unsteadiness during prolonged standing.
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Affiliation(s)
- Florian Schöberl
- 1 Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Katharina Feil
- 1 Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Guoming Xiong
- 2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Peter Bartenstein
- 2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,3 Department of Nuclear Medicine, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,4 Munich Cluster of Systems Neurology, SyNergy, Marchioninistr. 15, 81377 Munich, Germany
| | - Christian la Fougére
- 2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,5 Department of Nuclear Medicine, Eberhard Karls University, Röntgenweg 11, 72076 Tübingen, Germany
| | - Klaus Jahn
- 2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,6 Neurology, Schön Klinik Bad Aibling, Kolbermoorer Str. 72, 83043 Bad Aibling, Germany
| | - Thomas Brandt
- 2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,7 Clinical Neurosciences, Ludwig-Maximilians-Unversity, Marchioninistr. 15, 81377 Munich, Germany
| | - Michael Strupp
- 1 Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Marianne Dieterich
- 1 Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.,4 Munich Cluster of Systems Neurology, SyNergy, Marchioninistr. 15, 81377 Munich, Germany
| | - Andreas Zwergal
- 1 Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany .,2 German Center for Vertigo and Balance Disorders, DSGZ, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
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40
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Cerasa A, Quattrone A. Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence. THE CEREBELLUM 2017; 15:263-75. [PMID: 26626626 DOI: 10.1007/s12311-015-0739-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Essential tremor (ET) is the most common pathological tremor disorder in the world, and post-mortem evidence has shown that the cerebellum is the most consistent area of pathology in ET. In the last few years, advanced neuroimaging has tried to confirm this evidence. The aim of the present review is to discuss to what extent the evidence provided by this field of study may be generalised. We performed a systematic literature search combining the terms ET with the following keywords: MRI, VBM, MRS, DTI, fMRI, PET and SPECT. We summarised and discussed each study and placed the results in the context of existing knowledge regarding the cerebellar involvement in ET. A total of 51 neuroimaging studies met our search criteria, roughly divided into 19 structural and 32 functional studies. Despite clinical and methodological differences, both functional and structural imaging studies showed similar findings but without defining a clear topography of neurodegeneration. Indeed, the vast majority of studies found functional and structural abnormalities in several parts of the anterior and posterior cerebellar lobules, but it remains to be established to what degree these neural changes contribute to clinical symptoms of ET. Currently, advanced neuroimaging has confirmed the involvement of the cerebellum in pathophysiological processes of ET, although a high variability in results persists. For this reason, the translation of this knowledge into daily clinical practice is again partially limited, although new advanced multivariate neuroimaging approaches (machine-learning) are proving interesting changes of perspective.
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Affiliation(s)
| | - Aldo Quattrone
- IBFM, National Research Council, Catanzaro, CZ, Italy. .,Institute of Neurology, Department of Medical Sciences, University "Magna Graecia", Catanzaro, Italy.
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Abstract
A fundamental question about essential tremor (ET) is whether its associated pathological changes and disease mechanisms are linkable to a specific brain region. To that end, recent tissue-based studies have made significant strides in elucidating changes in the ET brain. Emerging from these studies is increasing neuropathological evidence linking ET to the cerebellum. These studies have systematically identified a broad range of structural, degenerative changes in the ET cerebellum, spanning across all Purkinje cell compartments. These include the dendritic compartment (where there is an increase in number of Purkinje cell dendritic swellings, a pruning of the dendritic arbor, and a reduction in spine density), the cell body (where, aside from reductions in Purkinje cell linear density in some studies, there is an increase in the number of heterotopic Purkinje cell soma), and the axonal compartment (where a plethora of changes in axonal morphology have been observed, including an increase in the number of thickened axonal profiles, torpedoes, axonal recurrent collaterals, axonal branching, and terminal axonal sprouting). Additional changes, possibly due to secondary remodeling, have been observed in neighboring neuronal populations. These include a hypertrophy of basket cell axonal processes and changes in the distribution of climbing fiber-Purkinje cell synapses. These changes all distinguish ET from normal control brains. Initial studies further indicate that the profile (i.e., constellation) of these changes may separate ET from other diseases of the cerebellum, thereby serving as a disease signature. With the discovery of these changes, a new model of ET has arisen, which posits that it may be a neurodegenerative disorder centered in the cerebellar cortex. These newly emerging neuropathological studies pave the way for anatomically focused, hypothesis-driven, molecular mechanistic studies of disease pathogenesis.
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Jang C, Park HJ, Chang WS, Pae C, Chang JW. Immediate and Longitudinal Alterations of Functional Networks after Thalamotomy in Essential Tremor. Front Neurol 2016; 7:184. [PMID: 27822200 PMCID: PMC5076435 DOI: 10.3389/fneur.2016.00184] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/10/2016] [Indexed: 12/12/2022] Open
Abstract
Thalamotomy at the ventralis intermedius nucleus has been an effective treatment method for essential tremor, but how the brain network changes immediately responding to this deliberate lesion and then reorganizes afterwards are not clear. Taking advantage of a non-cranium-opening MRI-guided focused ultrasound ablation technique, we investigated functional network changes due to a focal lesion. To classify the diverse time courses of those network changes with respect to symptom-related long-lasting treatment effects and symptom-unrelated transient effects, we applied graph-theoretic analyses to longitudinal resting-state functional magnetic resonance imaging data before and 1 day, 7 days, and 3 months after thalamotomy with essential tremor. We found reduced average connections among the motor-related areas, reduced connectivity between substantia nigra and external globus pallidum and reduced total connection in the thalamus after thalamotomy, which are all associated with clinical rating scales. The average connectivity among whole brain regions and inter-hemispheric network asymmetry show symptom-unrelated transient increases, indicating temporary reconfiguration of the whole brain network. In summary, thalamotomy regulates interactions over the motor network via symptom-related connectivity changes but accompanies transient, symptom-unrelated diaschisis in the global brain network. This study suggests the significance of longitudinal network analysis, combined with minimal-invasive treatment techniques, in understanding time-dependent diaschisis in the brain network due to a focal lesion.
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Affiliation(s)
- Changwon Jang
- BK21 PLUS Project for Medical Science, Severance Hospital, Yonsei University College of Medicine , Seoul , South Korea
| | - Hae-Jeong Park
- BK21 PLUS Project for Medical Science, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea; Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea; Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea; Department of Psychiatry, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea; Department of Cognitive Science, Yonsei University, Seoul, South Korea
| | - Won Seok Chang
- Department of Neurosurgery, Yonsei University College of Medicine , Seoul , South Korea
| | - Chongwon Pae
- BK21 PLUS Project for Medical Science, Severance Hospital, Yonsei University College of Medicine , Seoul , South Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Yonsei University College of Medicine , Seoul , South Korea
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Gibson WS, Jo HJ, Testini P, Cho S, Felmlee JP, Welker KM, Klassen BT, Min HK, Lee KH. Functional correlates of the therapeutic and adverse effects evoked by thalamic stimulation for essential tremor. Brain 2016; 139:2198-210. [PMID: 27329768 PMCID: PMC4958905 DOI: 10.1093/brain/aww145] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/03/2016] [Indexed: 01/05/2023] Open
Abstract
Thalamic deep brain stimulation (DBS) is an effective therapy for essential tremor. Gibson et al. use functional MRI to reveal patterns of activation that correlate with stimulation-induced therapeutic and adverse effects. Their results suggest that thalamic DBS controls tremor, and induces paraesthesias, through distal modulation of tremor-related network nodes. Deep brain stimulation is an established neurosurgical therapy for movement disorders including essential tremor and Parkinson’s disease. While typically highly effective, deep brain stimulation can sometimes yield suboptimal therapeutic benefit and can cause adverse effects. In this study, we tested the hypothesis that intraoperative functional magnetic resonance imaging could be used to detect deep brain stimulation-evoked changes in functional and effective connectivity that would correlate with the therapeutic and adverse effects of stimulation. Ten patients receiving deep brain stimulation of the ventralis intermedius thalamic nucleus for essential tremor underwent functional magnetic resonance imaging during stimulation applied at a series of stimulation localizations, followed by evaluation of deep brain stimulation-evoked therapeutic and adverse effects. Correlations between the therapeutic effectiveness of deep brain stimulation (3 months postoperatively) and deep brain stimulation-evoked changes in functional and effective connectivity were assessed using region of interest-based correlation analysis and dynamic causal modelling, respectively. Further, we investigated whether brain regions might exist in which activation resulting from deep brain stimulation might correlate with the presence of paraesthesias, the most common deep brain stimulation-evoked adverse effect. Thalamic deep brain stimulation resulted in activation within established nodes of the tremor circuit: sensorimotor cortex, thalamus, contralateral cerebellar cortex and deep cerebellar nuclei (FDR q < 0.05). Stimulation-evoked activation in all these regions of interest, as well as activation within the supplementary motor area, brainstem, and inferior frontal gyrus, exhibited significant correlations with the long-term therapeutic effectiveness of deep brain stimulation (P < 0.05), with the strongest correlation (P < 0.001) observed within the contralateral cerebellum. Dynamic causal modelling revealed a correlation between therapeutic effectiveness and attenuated within-region inhibitory connectivity in cerebellum. Finally, specific subregions of sensorimotor cortex were identified in which deep brain stimulation-evoked activation correlated with the presence of unwanted paraesthesias. These results suggest that thalamic deep brain stimulation in tremor likely exerts its effects through modulation of both olivocerebellar and thalamocortical circuits. In addition, our findings indicate that deep brain stimulation-evoked functional activation maps obtained intraoperatively may contain predictive information pertaining to the therapeutic and adverse effects induced by deep brain stimulation.
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Affiliation(s)
- William S Gibson
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Hang Joon Jo
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Paola Testini
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Shinho Cho
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Joel P Felmlee
- 2 Department of Radiology, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Kirk M Welker
- 2 Department of Radiology, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Bryan T Klassen
- 3 Department of Neurology, Mayo Clinic, Rochester, MN, USA 55905, USA
| | - Hoon-Ki Min
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA 2 Department of Radiology, Mayo Clinic, Rochester, MN, USA 55905, USA 4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, 55905, USA
| | - Kendall H Lee
- 1 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA 55905, USA 4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, 55905, USA
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Novellino F, Nicoletti G, Cherubini A, Caligiuri ME, Nisticò R, Salsone M, Morelli M, Arabia G, Cavalli SM, Vaccaro MG, Chiriaco C, Quattrone A. Cerebellar involvement in essential tremor with and without resting tremor: A Diffusion Tensor Imaging study. Parkinsonism Relat Disord 2016; 27:61-6. [DOI: 10.1016/j.parkreldis.2016.03.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/02/2016] [Accepted: 03/28/2016] [Indexed: 11/17/2022]
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Wallentin M, Skakkebæk A, Bojesen A, Fedder J, Laurberg P, Østergaard JR, Hertz JM, Pedersen AD, Gravholt CH. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation. Neuroimage Clin 2016; 11:239-251. [PMID: 26958463 PMCID: PMC4773384 DOI: 10.1016/j.nicl.2016.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/24/2016] [Accepted: 02/10/2016] [Indexed: 11/20/2022]
Abstract
Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.
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Affiliation(s)
- Mikkel Wallentin
- Center of Functionally Integrative Neuroscience, Aarhus University Hospital, building 10-G-5, Nørrebrogade, 8000 Aarhus C, Denmark; Center for Semiotics, Aarhus University, Denmark.
| | - Anne Skakkebæk
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, 8000 Aarhus C, Denmark; Department of Clinical Genetics, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Anders Bojesen
- Department of Clinical Genetics, Vejle Hospital, Sygehus Lillebaelt, 7100 Vejle, Denmark; Institute of Regional Health Research, University of Southern Denmark, 5000 Odense C, Denmark
| | - Jens Fedder
- Centre of Andrology & Fertility Clinic, Department D, Odense University Hospital, 5000 Odense C, Denmark
| | - Peter Laurberg
- Department of Endocrinology, Aalborg University Hospital, 9000 Aalborg, Denmark
| | - John R Østergaard
- Centre for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Denmark
| | - Jens Michael Hertz
- Department of Clinical Genetics, Odense University Hospital, 5000 Odense, Denmark
| | - Anders Degn Pedersen
- Vejlefjord Rehabilitation Center, 7140 Stouby, Denmark; Department of Psychology and Behavioral Sciences, Aarhus University, 8000 Aarhus, Denmark
| | - Claus Højbjerg Gravholt
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, 8000 Aarhus C, Denmark; Department of Molecular Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark
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Broersma M, van der Stouwe AMM, Buijink AWG, de Jong BM, Groot PFC, Speelman JD, Tijssen MAJ, van Rootselaar AF, Maurits NM. Bilateral cerebellar activation in unilaterally challenged essential tremor. NEUROIMAGE-CLINICAL 2015; 11:1-9. [PMID: 26909321 PMCID: PMC4732188 DOI: 10.1016/j.nicl.2015.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/23/2015] [Accepted: 12/24/2015] [Indexed: 01/12/2023]
Abstract
Background Essential tremor (ET) is one of the most common hyperkinetic movement disorders. Previous research into the pathophysiology of ET suggested underlying cerebellar abnormalities. Objective In this study, we added electromyography as an index of tremor intensity to functional Magnetic Resonance Imaging (EMG-fMRI) to study a group of ET patients selected according to strict criteria to achieve maximal homogeneity. With this approach we expected to improve upon the localization of the bilateral cerebellar abnormalities found in earlier fMRI studies. Methods We included 21 propranolol sensitive patients, who were not using other tremor medication, with a definite diagnosis of ET defined by the Tremor Investigation Group. Simultaneous EMG-fMRI recordings were performed while patients were off tremor medication. Patients performed unilateral right hand and arm extension, inducing tremor, alternated with relaxation (rest). Twenty-one healthy, age- and sex-matched participants mimicked tremor during right arm extension. EMG power variability at the individual tremor frequency as a measure of tremor intensity variability was used as a regressor, mathematically independent of the block regressor, in the general linear model used for fMRI analysis, to find specific tremor-related activations. Results Block-related activations were found in the classical upper-limb motor network, both for ET patients and healthy participants in motor, premotor and supplementary motor areas. In ET patients, we found tremor-related activations bilaterally in the cerebellum: in left lobules V, VI, VIIb and IX and in right lobules V, VI, VIIIa and b, and in the brainstem. In healthy controls we found simulated tremor-related activations in right cerebellar lobule V. Conclusions Our results expand on previous findings of bilateral cerebellar involvement in ET. We have identified specific areas in the bilateral somatomotor regions of the cerebellum: lobules V, VI and VIII.
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Affiliation(s)
- Marja Broersma
- Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands; Neuroimaging Center, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
| | - Anna M M van der Stouwe
- Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands; Neuroimaging Center, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
| | - Arthur W G Buijink
- Department of Neurology and Clinical Neurophysiology, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands; Brain Imaging Center, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands.
| | - Bauke M de Jong
- Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands; Neuroimaging Center, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
| | - Paul F C Groot
- Brain Imaging Center, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands; Department of Radiology, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands.
| | - Johannes D Speelman
- Department of Neurology and Clinical Neurophysiology, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands.
| | - Marina A J Tijssen
- Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands; Neuroimaging Center, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
| | - Anne-Fleur van Rootselaar
- Department of Neurology and Clinical Neurophysiology, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands; Brain Imaging Center, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands.
| | - Natasha M Maurits
- Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands; Neuroimaging Center, University Medical Center Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
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Chalah MA, Lefaucheur JP, Ayache SS. Non-invasive Central and Peripheral Stimulation: New Hope for Essential Tremor? Front Neurosci 2015; 9:440. [PMID: 26635516 PMCID: PMC4649015 DOI: 10.3389/fnins.2015.00440] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/01/2015] [Indexed: 12/31/2022] Open
Abstract
Essential tremor (ET) is among the most frequent movement disorders. It usually manifests as a postural and kinematic tremor of the arms, but may also involve the head, voice, lower limbs, and trunk. An oscillatory network has been proposed as a neural correlate of ET, and is mainly composed of the olivocerebellar system, thalamus, and motor cortex. Since pharmacological agents have limited benefits, surgical interventions like deep brain stimulation are the last-line treatment options for the most severe cases. Non-invasive brain stimulation techniques, particularly transcranial magnetic or direct current stimulation, are used to ameliorate ET. Their non-invasiveness, along with their side effects profile, makes them an appealing treatment option. In addition, peripheral stimulation has been applied in the same perspective. Hence, the aim of the present review is to shed light on the emergent use of non-invasive central and peripheral stimulation techniques in this interesting context.
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Affiliation(s)
- Moussa A Chalah
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil Créteil, France ; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris Créteil, France
| | - Jean-Pascal Lefaucheur
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil Créteil, France ; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris Créteil, France
| | - Samar S Ayache
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil Créteil, France ; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris Créteil, France ; Neurology Division, University Medical Center Rizk Hospital Beirut, Lebanon
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48
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Correlates Between Force and Postural Tremor in Older Individuals with Essential Tremor. THE CEREBELLUM 2015; 15:688-695. [DOI: 10.1007/s12311-015-0732-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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49
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Fang W, Chen H, Wang H, Zhang H, Puneet M, Liu M, Lv F, Luo T, Cheng O, Wang X, Lu X. Essential tremor is associated with disruption of functional connectivity in the ventral intermediate Nucleus--Motor Cortex--Cerebellum circuit. Hum Brain Mapp 2015; 37:165-78. [PMID: 26467643 DOI: 10.1002/hbm.23024] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 09/05/2015] [Accepted: 09/28/2015] [Indexed: 01/09/2023] Open
Abstract
The clinical benefits of targeting the ventral intermediate nucleus (VIM) for the treatment of tremors in essential tremor (ET) patients suggest that the VIM is a key hub in the network of tremor generation and propagation and that the VIM can be considered as a seed region to study the tremor network. However, little is known about the central tremor network in ET patients. Twenty-six ET patients and 26 matched healthy controls (HCs) were included in this study. After considering structural and head-motion factors and establishing the accuracy of our seed region, a VIM seed-based functional connectivity (FC) analysis of resting-state functional magnetic resonance imaging (RS-fMRI) data was performed to characterize the VIM FC network in ET patients. We found that ET patients and HCs shared a similar VIM FC network that was generally consistent with the VIM anatomical connectivity network inferred from normal nonhuman primates and healthy humans. Compared with HCs, ET patients displayed VIM-related FC changes, primarily within the VIM-motor cortex (MC)-cerebellum (CBLM) circuit, which included decreased FC in the CBLM and increased FC in the MC. Importantly, tremor severity correlated with these FC changes. These findings provide the first evidence that the pathological tremors observed in ET patients might be based on a physiologically pre-existing VIM - MC - CBLM network and that disruption of FC in this physiological network is associated with ET. Further, these findings demonstrate a potential approach for elucidating the neural network mechanisms underlying this disease.
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Affiliation(s)
- Weidong Fang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Huiyue Chen
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hansheng Wang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Han Zhang
- Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China
| | - Munankami Puneet
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mengqi Liu
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Fajin Lv
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Tianyou Luo
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Oumei Cheng
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xuefeng Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiurong Lu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Solbach K, Mumm M, Brandauer B, Kronenbürger M, Hermsdörfer J, Timmann D. Prehension Kinematics, Grasping Forces, and Independent Finger Control in Mildly Affected Patients with Essential Tremor. THE CEREBELLUM 2015; 15:498-508. [PMID: 26310449 DOI: 10.1007/s12311-015-0717-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although the pathophysiology of essential tremor (ET), one of the most common movement disorders, is not fully understood, evidence increasingly points to cerebellar involvement. To confirm this connection, we assessed the everyday hand and finger movements of patients with ET, as these movements are known to be affected in cerebellar diseases. In 26 mildly affected patients with ET (compared to age- and gender-matched controls), kinematic and finger force parameters were assessed in a precision grip. In a second task, independent finger movements were recorded. The active finger had to press and release against a force-sensitive keypad while the other fingers stayed inactive. Finally, control of grip force to movement-induced, self-generated load changes was studied. Transport and shaping components during prehension were significantly impaired in patients with ET compared to controls. No significant group differences were observed in independent finger movements and grip force adjustments to self-generated load force changes. However, in the latter two tasks, more severely affected ET patients performed worse than less affected. Although observed deficits in hand and finger movement tasks were small, they are consistent with cerebellar dysfunction in ET. Findings need to be confirmed in future studies examining more severely affected ET patients.
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Affiliation(s)
- Kasja Solbach
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.
| | - Mareike Mumm
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.,Department of Pediatrics, St. Vinzenz-Hospital, Dinslaken, Germany
| | - Barbara Brandauer
- Department of Neurology, University of Duisburg-Essen, Essen, Germany.,Clinical Psychology and Psychotherapy, University of Hamburg, Hamburg, Germany
| | | | - Joachim Hermsdörfer
- Department of Sport and Health Sciences, Institute of Movement Science, Technische Universität München, 80992, Munich, Germany
| | - Dagmar Timmann
- Department of Neurology, University of Duisburg-Essen, Essen, Germany
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