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Steina A, Sure S, Butz M, Vesper J, Schnitzler A, Hirschmann J. Mapping Subcortico-Cortical Coupling-A Comparison of Thalamic and Subthalamic Oscillations. Mov Disord 2024; 39:684-693. [PMID: 38380765 DOI: 10.1002/mds.29730] [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: 06/27/2023] [Revised: 11/29/2023] [Accepted: 01/08/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND The ventral intermediate nucleus of the thalamus (VIM) is an effective target for deep brain stimulation in tremor patients. Despite its therapeutic importance, its oscillatory coupling to cortical areas has rarely been investigated in humans. OBJECTIVES The objective of this study was to identify the cortical areas coupled to the VIM in patients with essential tremor. METHODS We combined resting-state magnetoencephalography with local field potential recordings from the VIM of 19 essential tremor patients. Whole-brain maps of VIM-cortex coherence in several frequency bands were constructed using beamforming and compared with corresponding maps of subthalamic nucleus (STN) coherence based on data from 19 patients with Parkinson's disease. In addition, we computed spectral Granger causality. RESULTS The topographies of VIM-cortex and STN-cortex coherence were very similar overall but differed quantitatively. Both nuclei were coupled to the ipsilateral sensorimotor cortex in the high-beta band; to the sensorimotor cortex, brainstem, and cerebellum in the low-beta band; and to the temporal cortex, brainstem, and cerebellum in the alpha band. High-beta coherence to sensorimotor cortex was stronger for the STN (P = 0.014), whereas low-beta coherence to the brainstem was stronger for the VIM (P = 0.017). Although the STN was driven by cortical activity in the high-beta band, the VIM led the sensorimotor cortex in the alpha band. CONCLUSIONS Thalamo-cortical coupling is spatially and spectrally organized. The overall similar topographies of VIM-cortex and STN-cortex coherence suggest that functional connections are not necessarily unique to one subcortical structure but might reflect larger frequency-specific networks involving VIM and STN to a different degree. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Alexandra Steina
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Sarah Sure
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Markus Butz
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Jan Vesper
- Department of Functional Neurosurgery and Stereotaxy, Neurosurgical Clinic, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Jan Hirschmann
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
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Guehl D, Guillaud E, Langbour N, Doat E, Auzou N, Courtin E, Branchard O, Engelhardt J, Benazzouz A, Eusebio A, Cuny E, Burbaud P. Usefulness of thalamic beta activity for closed-loop therapy in essential tremor. Sci Rep 2023; 13:22332. [PMID: 38102180 PMCID: PMC10724233 DOI: 10.1038/s41598-023-49511-5] [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: 05/18/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023] Open
Abstract
A partial loss of effectiveness of deep brain stimulation of the ventral intermediate nucleus of the thalamus (VIM) has been reported in some patients with essential tremor (ET), possibly due to habituation to permanent stimulation. This study focused on the evolution of VIM local-field potentials (LFPs) data over time to assess the long-term feasibility of closed-loop therapy based on thalamic activity. We performed recordings of thalamic LFPs in 10 patients with severe ET using the ACTIVA™ PC + S (Medtronic plc.) allowing both recordings and stimulation in the same region. Particular attention was paid to describing the evolution of LFPs over time from 3 to 24 months after surgery when the stimulation was Off. We demonstrated a significant decrease in high-beta LFPs amplitude during movements inducing tremor in comparison to the rest condition 3 months after surgery (1.91 ± 0.89 at rest vs. 1.27 ± 1.37 µV2/Hz during posture/action for N = 8/10 patients; p = 0.010), 12 months after surgery (2.92 ± 1.75 at rest vs. 2.12 ± 1.78 µV2/Hz during posture/action for N = 7/10 patients; p = 0.014) and 24 months after surgery (2.32 ± 0.35 at rest vs 0.75 ± 0.78 µV2/Hz during posture/action for 4/6 patients; p = 0.017). Among the patients who exhibited a significant decrease of high-beta LFP amplitude when stimulation was Off, this phenomenon was observed at least twice during the follow-up. Although the extent of this decrease in high-beta LFPs amplitude during movements inducing tremor may vary over time, this thalamic biomarker of movement could potentially be usable for closed-loop therapy in the long term.
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Affiliation(s)
- Dominique Guehl
- Service de Neurophysiologie Clinique de l'enfant et de l'adulte, Hôpital Pellegrin, Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France.
- Institut des Maladies Neurodégénératives, Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000, Bordeaux, France.
| | - Etienne Guillaud
- Institute of Cognitive and Integrative Neurosciences, Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | - Nicolas Langbour
- Centre de Recherche en Psychiatrie, CH de la Milétrie, 86000, Poitiers, France
| | - Emilie Doat
- Institute of Cognitive and Integrative Neurosciences, Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | - Nicolas Auzou
- Institut des Maladies Neurodégénératives Clinique (IMNc), Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
| | - Edouard Courtin
- Service de Neurophysiologie Clinique de l'enfant et de l'adulte, Hôpital Pellegrin, Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
| | | | | | - Abdelhamid Benazzouz
- Institut des Maladies Neurodégénératives, Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000, Bordeaux, France
| | - Alexandre Eusebio
- Department of Neurology and Movement Disorders, APHM, Hôpitaux Universitaire de Marseille, Marseille, France
- Institut de Neurosciences de la Timone, UMR 7289, Aix Marseille Univ, CNRS, Marseille, France
| | - Emmanuel Cuny
- Service de Neurochirurgie, CHU de Bordeaux, Bordeaux, France
| | - Pierre Burbaud
- Service de Neurophysiologie Clinique de l'enfant et de l'adulte, Hôpital Pellegrin, Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
- Institut des Maladies Neurodégénératives, Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000, Bordeaux, France
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Colella D, Passaretti M, Frantellizzi V, Silvia De Feo M, Cannavacciuolo A, Angelini L, Birreci D, Costa D, Paparella G, Guerra A, De Vincentis G, Berardelli A, Bologna M. Subtle changes in central dopaminergic tone underlie bradykinesia in essential tremor. Neuroimage Clin 2023; 40:103526. [PMID: 37847966 PMCID: PMC10587600 DOI: 10.1016/j.nicl.2023.103526] [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: 07/30/2023] [Revised: 09/25/2023] [Accepted: 10/09/2023] [Indexed: 10/19/2023]
Abstract
INTRODUCTION In this research, our primary objective was to explore the correlation between basal ganglia dopaminergic neurotransmission, assessed using 123I-FP-CIT (DAT-SPECT), and finger movements abnormalities in patients with essential tremor (ET) and Parkinson's disease (PD). METHODS We enrolled 16 patients with ET, 17 with PD, and 18 healthy controls (HC). Each participant underwent comprehensive clinical evaluations, kinematic assessments of finger tapping. ET and PD patients underwent DAT-SPECT imaging. The DAT-SPECT scans were subjected to both visual and semi-quantitative analysis using DaTQUANT®. We then investigated the correlations between the clinical, kinematic, and DAT-SPECT data, in patients. RESULTS Our findings confirm that individuals with ET exhibited slower finger tapping than HC. Visual evaluation of radiotracer uptake in both striata demonstrated normal levels within the ET patient cohort, while PD patients displayed reduced uptake. However, there was notable heterogeneity in the quantification of uptake within the striata among ET patients. Additionally, we found a correlation between the amount of radiotracer uptake in the striatum and movement velocity during finger tapping in patients. Specifically, lower radioligand uptake corresponded to decreased movement velocity (ET: coef. = 0.53, p-adj = 0.03; PD: coef. = 0.59, p-adj = 0.01). CONCLUSION The study's findings suggest a potential link between subtle changes in central dopaminergic tone and altered voluntary movement execution, in ET. These results provide further insights into the pathophysiology of ET. However, longitudinal studies are essential to determine whether the slight reduction in dopaminergic tone observed in ET patients represents a distinct subtype of the disease or could serve as a predictor for the clinical progression into PD.
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Affiliation(s)
- Donato Colella
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Massimiliano Passaretti
- Department of Human Neurosciences, Sapienza University of Rome, Italy; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Viviana Frantellizzi
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Italy
| | - Maria Silvia De Feo
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Italy
| | | | - Luca Angelini
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Daniele Birreci
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Davide Costa
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Giulia Paparella
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed Pozzilli (IS), Italy
| | - Andrea Guerra
- Parkinson and Movement Disorder Unit, Study Center on Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Padua, Italy
| | - Giuseppe De Vincentis
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed Pozzilli (IS), Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed Pozzilli (IS), Italy.
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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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Matthews LG, Puryear CB, Correia SS, Srinivasan S, Belfort GM, Pan MK, Kuo SH. T-type calcium channels as therapeutic targets in essential tremor and Parkinson's disease. Ann Clin Transl Neurol 2023; 10:462-483. [PMID: 36738196 PMCID: PMC10109288 DOI: 10.1002/acn3.51735] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 02/05/2023] Open
Abstract
Neuronal action potential firing patterns are key components of healthy brain function. Importantly, restoring dysregulated neuronal firing patterns has the potential to be a promising strategy in the development of novel therapeutics for disorders of the central nervous system. Here, we review the pathophysiology of essential tremor and Parkinson's disease, the two most common movement disorders, with a focus on mechanisms underlying the genesis of abnormal firing patterns in the implicated neural circuits. Aberrant burst firing of neurons in the cerebello-thalamo-cortical and basal ganglia-thalamo-cortical circuits contribute to the clinical symptoms of essential tremor and Parkinson's disease, respectively, and T-type calcium channels play a key role in regulating this activity in both the disorders. Accordingly, modulating T-type calcium channel activity has received attention as a potentially promising therapeutic approach to normalize abnormal burst firing in these diseases. In this review, we explore the evidence supporting the theory that T-type calcium channel blockers can ameliorate the pathophysiologic mechanisms underlying essential tremor and Parkinson's disease, furthering the case for clinical investigation of these compounds. We conclude with key considerations for future investigational efforts, providing a critical framework for the development of much needed agents capable of targeting the dysfunctional circuitry underlying movement disorders such as essential tremor, Parkinson's disease, and beyond.
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Affiliation(s)
| | - Corey B Puryear
- Praxis Precision Medicines, Boston, Massachusetts, 02110, USA
| | | | - Sharan Srinivasan
- Praxis Precision Medicines, Boston, Massachusetts, 02110, USA.,Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | | | - Ming-Kai Pan
- Department and Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, 10051, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, 10617, Taiwan.,Department of Medical Research, National Taiwan University Hospital, Taipei, 10002, Taiwan.,Cerebellar Research Center, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin, 64041, Taiwan
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, New York, 10032, USA.,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, New York, 10032, USA
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6
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Srinivasan SR. Targeting Circuit Abnormalities in Neurodegenerative Disease. Mol Pharmacol 2023; 103:38-44. [PMID: 36310030 DOI: 10.1124/molpharm.122.000563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/18/2022] [Accepted: 10/24/2022] [Indexed: 02/03/2023] Open
Abstract
Despite significant improvement in our ability to diagnose both common and rare neurodegenerative diseases and understand their underlying biologic mechanisms, there remains a disproportionate lack of effective treatments, reflecting the complexity of these disorders. Successfully advancing novel treatments for neurodegenerative disorders will require reconsideration of traditional approaches, which to date have focused largely on specific disease proteins or cells of origin. This article proposes reframing these diseases as conditions of dysfunctional circuitry as a complement to ongoing efforts. Specifically reviewed is how aberrant spiking is a common downstream mechanism in numerous neurodegenerative diseases, often driven by dysfunction in specific ion channels. Surgical modification of this electrical activity via deep brain stimulation is already an approved modality for many of these disorders. Therefore, restoring proper electrical activity by targeting these channels pharmacologically represents a viable strategy for intervention, not only for symptomatic management but also as a potential disease-modifying therapy. Such an approach is likely to be a promising route to treating these devastating disorders, either as monotherapy or in conjunction with current drugs. SIGNIFICANCE STATEMENT: Despite extensive research and improved understanding of the biology driving neurodegenerative disease, there has not been a concomitant increase in approved therapies. Accordingly, it is time to shift our perspective and recognize these diseases also as disorders of circuitry to further yield novel drug targets and new interventions. An approach focused on treating dysfunctional circuitry has the potential to reduce or reverse patient symptoms and potentially modify disease course.
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7
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Lu H, Lin J, Xiong Y, Deng L, Wang X, Zhang D, Bian X, Zhou J, Pan L, Lou X. Assessing the impact of MR-guided focused ultrasound thalamotomy on brain activity and connectivity in patients with essential tremor. Neurosurg Focus 2022; 53:E5. [PMID: 36455269 DOI: 10.3171/2022.9.focus22228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 09/20/2022] [Indexed: 12/04/2022]
Abstract
OBJECTIVE Although magnetic resonance-guided focused ultrasound (MRgFUS) at the ventral intermediate (VIM) thalamic nucleus is a novel and effective treatment for medication-refractory essential tremor (ET), it is unclear how the ablation lesion affects functional activity. The current study sought to evaluate the functional impact of MRgFUS thalamotomy in patients with ET, as well as to investigate the relationship between neuronal activity changes and tremor control. METHODS This study included 30 patients with ET who underwent MRgFUS thalamotomy with a 6-month follow-up involving MRI and clinical tremor rating. Additional sex- and age-matched healthy people were recruited for the healthy control group. The fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity were used to identify functional alteration regions of interest (ROIs). To investigate changes after treatment, ROI- and seed-based functional connectivity (FC) analyses were performed. RESULTS Patients with ET had significantly increased fALFF in the right postcentral gyrus (PoCG; ROI 1), regional homogeneity in the left PoCG (ROI 2), and regional homogeneity in the right PoCG (ROI 3, cluster-level p value family-wise error [pFWE] < 0.05), which were recovered and normalized at 6 months after MRgFUS thalamotomy. FCs between ROI 2 and the right supramarginal gyrus, ROI 2 and the right superior parietal gyrus, and ROI 3 and the left precentral gyrus were also found to be increased after treatment (cluster-level pFWE < 0.05). Furthermore, changes in fALFF, regional homogeneity, and FC values were significantly correlated with tremor relief (p < 0.05). Preoperative FC strengths were found to be inversely related to the postoperative tremor control ratio (p < 0.05). CONCLUSIONS In patients with ET, the VIM lesion of MRgFUS thalamotomy resulted in symptom-related regional functional recovery associated with sensorimotor and attention networks. Preoperative FC strengths may reflect the postoperative tremor control ratio, implying that this metric could be a useful neuroimaging biomarker for predicting symptom relief in patients with ET following thalamotomy.
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Affiliation(s)
| | | | | | | | | | | | | | - Jiayou Zhou
- 2Neurosurgery, Chinese PLA General Hospital/Chinese PLA Medical School, Beijing, China
| | - Longsheng Pan
- 2Neurosurgery, Chinese PLA General Hospital/Chinese PLA Medical School, Beijing, China
| | - Xin Lou
- Departments of1Radiology and
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Lee J, Kim J, Cortez J, Chang SY. Thalamo-cortical network is associated with harmaline-induced tremor in rodent model. Exp Neurol 2022; 358:114210. [PMID: 36007599 DOI: 10.1016/j.expneurol.2022.114210] [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: 07/31/2022] [Accepted: 08/19/2022] [Indexed: 11/04/2022]
Abstract
Essential tremor (ET) is the most frequent form of pathologic tremor and one of the most common adult-onset neurologic impairments. However, underlying mechanisms by which structural alterations within the tremor circuit generate the pathological state and how rhythmic neuronal activities propagate and drive tremor remains unclear. Harmaline (HA)-induced tremor model has been most frequently utilized animal model for ET studies, however, there is still a dearth of knowledge over the degree to whether HA-induced tremor mimics the actual underlying pathophysiology of ET, particularly the involvement of thalamo-cortical region. In this study, we investigated the electrophysiological response of the motor circuit including the ventrolateral thalamus (vlTh) and the primary motor cortex (M1), and the modulatory effect of thalamic deep brain stimulation (DBS) using a rat HA-induced tremor model. We found that the theta and high-frequency oscillation (HFO) band power significantly increased after HA administration in both vlTh and M1, and the activity was modulated by the tremor suppression drug (propranolol) and the thalamic DBS. The theta band phase synchronization between the vlTh and M1 was significantly enhanced during the HA-induced tremor, and the transition of cross-frequency coupling in vlTh was found to be associated with the state of HA-induced tremor. Our findings support that the HA tremor could be useful as a valid preclinical model of ET in the context of thalamo-cortical neural network interaction.
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Affiliation(s)
- Jeyeon Lee
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Jiwon Kim
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Joshua Cortez
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Su-Youne Chang
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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Wagle Shukla A. Reduction of neuronal hyperexcitability with modulation of T-type calcium channel or SK channel in essential tremor. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:335-355. [PMID: 35750369 DOI: 10.1016/bs.irn.2022.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Essential tremor is one of the most prevalent movement disorders. Propranolol and primidone are the first-line pharmacological therapies. They provide symptomatic control in less than 50% of patients. Topiramate, alprazolam, clonazepam, gabapentin, and botulinum toxin injections are the next line of treatments. These medications lead to modest improvements and are therefore commonly used as add-on agents. Surgical therapies, including deep brain stimulation (DBS) surgery and focused ultrasound beam targeted to the thalamus, are considered for treating tremor refractory to medications and lead to greater than 75% improvements in tremor symptoms. However, DBS is a costly and an invasive procedure; some patients report tolerance to benefits. Focused ultrasound therapy leading to brain lesions is associated with a possibility for permanent clinical deficits. Therefore, research efforts to develop the next generation of oral medications with greater benefits and lesser adverse effects are warranted. There is considerable evidence that the increased functions of calcium channels (P/Q-type and T-type channels) and reduced functions of calcium-activated potassium channels (SK channels) located in the neuronal membranes lead to tremor oscillations. Consequently, many new pharmacological studies have targeted these channels to leverage better clinical outcomes. The current review will discuss the pathophysiology, the specific importance of these channels, and the early clinical experience of using compounds targeting these channels to treat essential tremor.
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Affiliation(s)
- Aparna Wagle Shukla
- Department of Neurology, Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States.
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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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Acute Cerebellar Inflammation and Related Ataxia: Mechanisms and Pathophysiology. Brain Sci 2022; 12:brainsci12030367. [PMID: 35326323 PMCID: PMC8946185 DOI: 10.3390/brainsci12030367] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 12/11/2022] Open
Abstract
The cerebellum governs motor coordination and motor learning. Infection with external microorganisms, such as viruses, bacteria, and fungi, induces the release and production of inflammatory mediators, which drive acute cerebellar inflammation. The clinical observation of acute cerebellitis is associated with the emergence of cerebellar ataxia. In our animal model of the acute inflammation of the cerebellar cortex, animals did not show any ataxia but hyperexcitability in the cerebellar cortex and depression-like behaviors. In contrast, animal models with neurodegeneration of the cerebellar Purkinje cells and hypoexcitability of the neurons show cerebellar ataxia. The suppression of the Ca2+-activated K+ channels in vivo is associated with a type of ataxia. Therefore, there is a gap in our interpretation between the very early phase of cerebellar inflammation and the emergence of cerebellar ataxia. In this review, we discuss the hypothesized scenario concerning the emergence of cerebellar ataxia. First, compared with genetically induced cerebellar ataxias, we introduce infection and inflammation in the cerebellum via aberrant immunity and glial responses. Especially, we focus on infections with cytomegalovirus, influenza virus, dengue virus, and SARS-CoV-2, potential relevance to mitochondrial DNA, and autoimmunity in infection. Second, we review neurophysiological modulation (intrinsic excitability, excitatory, and inhibitory synaptic transmission) by inflammatory mediators and aberrant immunity. Next, we discuss the cerebellar circuit dysfunction (presumably, via maintaining the homeostatic property). Lastly, we propose the mechanism of the cerebellar ataxia and possible treatments for the ataxia in the cerebellar inflammation.
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Woodward K, Apps R, Goodfellow M, Cerminara NL. Cerebello-Thalamo-Cortical Network Dynamics in the Harmaline Rodent Model of Essential Tremor. Front Syst Neurosci 2022; 16:899446. [PMID: 35965995 PMCID: PMC9365993 DOI: 10.3389/fnsys.2022.899446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/22/2022] [Indexed: 11/18/2022] Open
Abstract
Essential Tremor (ET) is a common movement disorder, characterised by a posture or movement-related tremor of the upper limbs. Abnormalities within cerebellar circuits are thought to underlie the pathogenesis of ET, resulting in aberrant synchronous oscillatory activity within the thalamo-cortical network leading to tremors. Harmaline produces pathological oscillations within the cerebellum, and a tremor that phenotypically resembles ET. However, the neural network dynamics in cerebellar-thalamo-cortical circuits in harmaline-induced tremor remains unclear, including the way circuit interactions may be influenced by behavioural state. Here, we examined the effect of harmaline on cerebello-thalamo-cortical oscillations during rest and movement. EEG recordings from the sensorimotor cortex and local field potentials (LFP) from thalamic and medial cerebellar nuclei were simultaneously recorded in awake behaving rats, alongside measures of tremor using EMG and accelerometery. Analyses compared neural oscillations before and after systemic administration of harmaline (10 mg/kg, I.P), and coherence across periods when rats were resting vs. moving. During movement, harmaline increased the 9-15 Hz behavioural tremor amplitude and increased thalamic LFP coherence with tremor. Medial cerebellar nuclei and cerebellar vermis LFP coherence with tremor however remained unchanged from rest. These findings suggest harmaline-induced cerebellar oscillations are independent of behavioural state and associated changes in tremor amplitude. By contrast, thalamic oscillations are dependent on behavioural state and related changes in tremor amplitude. This study provides new insights into the role of cerebello-thalamo-cortical network interactions in tremor, whereby neural oscillations in thalamocortical, but not cerebellar circuits can be influenced by movement and/or behavioural tremor amplitude in the harmaline model.
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Affiliation(s)
- Kathryn Woodward
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Richard Apps
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Marc Goodfellow
- Department of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Nadia L. Cerminara
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
- *Correspondence: Nadia L. Cerminara
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13
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Essential tremor amplitude modulation by median nerve stimulation. Sci Rep 2021; 11:17720. [PMID: 34489503 PMCID: PMC8421420 DOI: 10.1038/s41598-021-96660-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 08/05/2021] [Indexed: 11/08/2022] Open
Abstract
Essential tremor is a common neurological disorder, characterised by involuntary shaking of a limb. Patients are usually treated using medications which have limited effects on tremor and may cause side-effects. Surgical therapies are effective in reducing essential tremor, however, the invasive nature of these therapies together with the high cost, greatly limit the number of patients benefiting from them. Non-invasive therapies have gained increasing traction to meet this clinical need. Here, we test a non-invasive and closed-loop electrical stimulation paradigm which tracks peripheral tremor and targets thalamic afferents to modulate the central oscillators underlying tremor. To this end, 9 patients had electrical stimulation delivered to the median nerve locked to different phases of tremor. Peripheral stimulation induced a subtle but significant modulation in five out of nine patients-this modulation consisted mainly of amplification rather than suppression of tremor amplitude. Modulatory effects of stimulation were more pronounced when patient's tremor was spontaneously weaker at stimulation onset, when significant modulation became more frequent amongst subjects. This data suggests that for selected individuals, a more sophisticated control policy entailing an online estimate of both tremor phase and amplitude, should be considered in further explorations of the treatment potential of tremor phase-locked peripheral stimulation.
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14
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Opri E, Cernera S, Molina R, Eisinger RS, Cagle JN, Almeida L, Denison T, Okun MS, Foote KD, Gunduz A. Chronic embedded cortico-thalamic closed-loop deep brain stimulation for the treatment of essential tremor. Sci Transl Med 2021; 12:12/572/eaay7680. [PMID: 33268512 DOI: 10.1126/scitranslmed.aay7680] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/14/2020] [Accepted: 08/25/2020] [Indexed: 11/02/2022]
Abstract
Deep brain stimulation (DBS) is an approved therapy for the treatment of medically refractory and severe movement disorders. However, most existing neurostimulators can only apply continuous stimulation [open-loop DBS (OL-DBS)], ignoring patient behavior and environmental factors, which consequently leads to an inefficient therapy, thus limiting the therapeutic window. Here, we established the feasibility of a self-adjusting therapeutic DBS [closed-loop DBS (CL-DBS)], fully embedded in a chronic investigational neurostimulator (Activa PC + S), for three patients affected by essential tremor (ET) enrolled in a longitudinal (6 months) within-subject crossover protocol (DBS OFF, OL-DBS, and CL-DBS). Most patients with ET experience involuntary limb tremor during goal-directed movements, but not during rest. Hence, the proposed CL-DBS paradigm explored the efficacy of modulating the stimulation amplitude based on patient-specific motor behavior, suppressing the pathological tremor on-demand based on a cortical electrode detecting upper limb motor activity. Here, we demonstrated how the proposed stimulation paradigm was able to achieve clinical efficacy and tremor suppression comparable with OL-DBS in a range of movements (cup reaching, proximal and distal posture, water pouring, and writing) while having a consistent reduction in energy delivery. The proposed paradigm is an important step toward a behaviorally modulated fully embedded DBS system, capable of delivering stimulation only when needed, and potentially mitigating pitfalls of OL-DBS, such as DBS-induced side effects and premature device replacement.
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Affiliation(s)
- Enrico Opri
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Stephanie Cernera
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Rene Molina
- Electrical and Computer Engineering, University of Florida, Gainesville, FL 32603, USA
| | - Robert S Eisinger
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Jackson N Cagle
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Leonardo Almeida
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Timothy Denison
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - Michael S Okun
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Kelly D Foote
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Aysegul Gunduz
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.,Electrical and Computer Engineering, University of Florida, Gainesville, FL 32603, USA.,Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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15
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Latorre A, Rocchi L, Sadnicka A. The Expanding Horizon of Neural Stimulation for Hyperkinetic Movement Disorders. Front Neurol 2021; 12:669690. [PMID: 34054710 PMCID: PMC8160223 DOI: 10.3389/fneur.2021.669690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
Novel methods of neural stimulation are transforming the management of hyperkinetic movement disorders. In this review the diversity of approach available is showcased. We first describe the most commonly used features that can be extracted from oscillatory activity of the central nervous system, and how these can be combined with an expanding range of non-invasive and invasive brain stimulation techniques. We then shift our focus to the periphery using tremor and Tourette's syndrome to illustrate the utility of peripheral biomarkers and interventions. Finally, we discuss current innovations which are changing the landscape of stimulation strategy by integrating technological advances and the use of machine learning to drive optimization.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, University College London, London, United Kingdom.,Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Anna Sadnicka
- Department of Clinical and Movement Neurosciences, University College London, London, United Kingdom.,Motor Control and Neuromodulation Group, St George's University of London, London, United Kingdom
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16
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Duchet B, Weerasinghe G, Bick C, Bogacz R. Optimizing deep brain stimulation based on isostable amplitude in essential tremor patient models. J Neural Eng 2021; 18:046023. [PMID: 33821809 PMCID: PMC7610712 DOI: 10.1088/1741-2552/abd90d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Deep brain stimulation is a treatment for medically refractory essential tremor. To improve the therapy, closed-loop approaches are designed to deliver stimulation according to the system's state, which is constantly monitored by recording a pathological signal associated with symptoms (e.g. brain signal or limb tremor). Since the space of possible closed-loop stimulation strategies is vast and cannot be fully explored experimentally, how to stimulate according to the state should be informed by modeling. A typical modeling goal is to design a stimulation strategy that aims to maximally reduce the Hilbert amplitude of the pathological signal in order to minimize symptoms. Isostables provide a notion of amplitude related to convergence time to the attractor, which can be beneficial in model-based control problems. However, how isostable and Hilbert amplitudes compare when optimizing the amplitude response to stimulation in models constrained by data is unknown. APPROACH We formulate a simple closed-loop stimulation strategy based on models previously fitted to phase-locked deep brain stimulation data from essential tremor patients. We compare the performance of this strategy in suppressing oscillatory power when based on Hilbert amplitude and when based on isostable amplitude. We also compare performance to phase-locked stimulation and open-loop high-frequency stimulation. MAIN RESULTS For our closed-loop phase space stimulation strategy, stimulation based on isostable amplitude is significantly more effective than stimulation based on Hilbert amplitude when amplitude field computation time is limited to minutes. Performance is similar when there are no constraints, however constraints on computation time are expected in clinical applications. Even when computation time is limited to minutes, closed-loop phase space stimulation based on isostable amplitude is advantageous compared to phase-locked stimulation, and is more efficient than high-frequency stimulation. SIGNIFICANCE Our results suggest a potential benefit to using isostable amplitude more broadly for model-based optimization of stimulation in neurological disorders.
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Affiliation(s)
- Benoit Duchet
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom. MRC Brain Network Dynamics Unit, University of Oxford, Oxford, United Kingdom
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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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18
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He F, Yang Y. Nonlinear System Identification of Neural Systems from Neurophysiological Signals. Neuroscience 2021; 458:213-228. [PMID: 33309967 PMCID: PMC7925423 DOI: 10.1016/j.neuroscience.2020.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022]
Abstract
The human nervous system is one of the most complicated systems in nature. Complex nonlinear behaviours have been shown from the single neuron level to the system level. For decades, linear connectivity analysis methods, such as correlation, coherence and Granger causality, have been extensively used to assess the neural connectivities and input-output interconnections in neural systems. Recent studies indicate that these linear methods can only capture a certain amount of neural activities and functional relationships, and therefore cannot describe neural behaviours in a precise or complete way. In this review, we highlight recent advances in nonlinear system identification of neural systems, corresponding time and frequency domain analysis, and novel neural connectivity measures based on nonlinear system identification techniques. We argue that nonlinear modelling and analysis are necessary to study neuronal processing and signal transfer in neural systems quantitatively. These approaches can hopefully provide new insights to advance our understanding of neurophysiological mechanisms underlying neural functions. These nonlinear approaches also have the potential to produce sensitive biomarkers to facilitate the development of precision diagnostic tools for evaluating neurological disorders and the effects of targeted intervention.
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Affiliation(s)
- Fei He
- Centre for Data Science, Coventry University, Coventry CV1 2JH, UK
| | - Yuan Yang
- Stephenson School of Biomedical Engineering, The University of Oklahoma, Tulsa, OK 74135, USA; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Laureate Institute for Brain Research, Tulsa, OK 74136, USA
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19
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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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20
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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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21
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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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Swan BD, Brocker DT, Gross RE, Turner DA, Grill WM. Effects of ramped-frequency thalamic deep brain stimulation on tremor and activity of modeled neurons. Clin Neurophysiol 2019; 131:625-634. [PMID: 31978847 DOI: 10.1016/j.clinph.2019.11.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 11/18/2019] [Accepted: 11/23/2019] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We conducted intraoperative measurements of tremor to quantify the effects of temporally patterned ramped-frequency DBS trains on tremor. METHODS Seven patterns of stimulation were tested in nine subjects with thalamic DBS for essential tremor: stimulation 'off', three ramped-frequency stimulation (RFS) trains from 130 → 50 Hz, 130 → 60 Hz, and 235 → 90 Hz, and three constant frequency stimulation (CFS) trains at 72, 82, and 130 Hz. The same patterns were applied to a computational model of the thalamic neural network. RESULTS Temporally patterned 130 → 60 Hz ramped-frequency trains suppressed tremor relative to stimulation 'off,' but 130 → 50 Hz, 130 → 60 Hz, and 235 → 90 Hz ramped-frequency trains were no more effective than constant frequency stimulation with the same mean interpulse interval (IPI). Computational modeling revealed that rhythmic burst-driver inputs to thalamus were masked during DBS, but long IPIs, concurrent with pauses in afferent cerebellar and cortical firing, allowed propagation of bursting activity. The mean firing rate of bursting-type model neurons as well as the firing pattern entropy of model neurons were both strongly correlated with tremor power across stimulation conditions. CONCLUSION Frequency-ramped DBS produced equivalent tremor suppression as constant frequency thalamic DBS. Tremor-related thalamic burst activity may result from burst-driver input, rather than by an intrinsic rebound mechanism. SIGNIFICANCE Ramping stimulation frequency may exacerbate thalamic burst firing by introducing consecutive pauses of increasing duration to the stimulation pattern.
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Affiliation(s)
- Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - David T Brocker
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University Hospital, Atlanta, GA, USA
| | - Dennis A Turner
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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Tuleasca C, Régis J, Najdenovska E, Witjas T, Girard N, Bolton T, Delaire F, Vincent M, Faouzi M, Thiran JP, Bach Cuadra M, Levivier M, Van de Ville D. Pretherapeutic resting-state fMRI profiles are associated with MR signature volumes after stereotactic radiosurgical thalamotomy for essential tremor. J Neurosurg 2019; 129:63-71. [PMID: 30544321 DOI: 10.3171/2018.7.gks18752] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/24/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVEEssential tremor (ET) is the most common movement disorder. Drug-resistant ET can benefit from standard stereotactic deep brain stimulation or radiofrequency thalamotomy or, alternatively, minimally invasive techniques, including stereotactic radiosurgery (SRS) and high-intensity focused ultrasound, at the level of the ventral intermediate nucleus (Vim). The aim of the present study was to evaluate potential correlations between pretherapeutic interconnectivity (IC), as depicted on resting-state functional MRI (rs-fMRI), and MR signature volume at 1 year after Vim SRS for tremor, to be able to potentially identify hypo- and hyperresponders based only on pretherapeutic neuroimaging data.METHODSSeventeen consecutive patients with ET were included, who benefitted from left unilateral SRS thalamotomy (SRS-T) between September 2014 and August 2015. Standard tremor assessment and rs-fMRI were acquired pretherapeutically and 1 year after SRS-T. A healthy control group was also included (n = 12). Group-level independent component analysis (ICA; only n = 17 for pretherapeutic rs-fMRI) was applied. The mean MR signature volume was 0.125 ml (median 0.063 ml, range 0.002-0.600 ml). The authors correlated baseline IC with 1-year MR signatures within all networks. A 2-sample t-test at the level of each component was first performed in two groups: group 1 (n = 8, volume < 0.063 ml) and group 2 (n = 9, volume ≥ 0.063 ml). These groups did not statistically differ by age, duration of symptoms, baseline ADL score, ADL point decrease at 1 year, time to tremor arrest, or baseline tremor score on the treated hand (TSTH; p > 0.05). An ANOVA was then performed on each component, using individual subject-level maps and continuous values of 1-year MR signatures, correlated with pretherapeutic IC.RESULTSUsing 2-sample t-tests, two networks were found to be statistically significant: network 3, including the brainstem, motor cerebellum, bilateral thalamus, and left supplementary motor area (SMA) (pFWE = 0.004, cluster size = 94), interconnected with the red nucleus (MNI -2, -22, -32); and network 9, including the brainstem, posterior insula, bilateral thalamus, and left SMA (pFWE = 0.002, cluster size = 106), interconnected with the left SMA (MNI 24, -28, 44). Higher pretherapeutic IC was associated with higher MR volumes, in a network including the anterior default-mode network and bilateral thalamus (ANOVA, pFWE = 0.004, cluster size = 73), interconnected with cerebellar lobule V (MNI -12, -70, -22). Moreover, in the same network, radiological hyporesponders presented with negative IC values.CONCLUSIONSThese findings have clinical implications for predicting MR signature volumes after SRS-T. Here, using pretherapeutic MRI and data processing without prior hypothesis, the authors showed that pretherapeutic network interconnectivity strength predicts 1-year MR signature volumes following SRS-T.
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Affiliation(s)
- Constantin Tuleasca
- 1Neurosurgery Service and Gamma Knife Center.,4Faculty of Biology and Medicine, University of Lausanne, Switzerland
| | - Jean Régis
- 5Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, and
| | - Elena Najdenovska
- 2Medical Image Analysis Laboratory (MIAL) and Department of Radiology, Centre d'Imagerie BioMédicale (CIBM), and
| | | | - Nadine Girard
- 7AMU, CRMBM UMR CNRS 7339, Faculté de Médecine et APHM, Hôpital Timone, Department of Diagnostic and Interventional Neuroradiology, Marseille, France
| | - Thomas Bolton
- 8Medical Image Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Francois Delaire
- 5Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, and
| | - Marion Vincent
- 5Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, and
| | - Mohamed Faouzi
- 9Institute of Social and Preventive Medicine, Lausanne, Switzerland; and
| | - Jean-Philippe Thiran
- 3Signal Processing Laboratory (LTS 5), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland.,4Faculty of Biology and Medicine, University of Lausanne, Switzerland.,10Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Meritxell Bach Cuadra
- 2Medical Image Analysis Laboratory (MIAL) and Department of Radiology, Centre d'Imagerie BioMédicale (CIBM), and.,3Signal Processing Laboratory (LTS 5), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Marc Levivier
- 1Neurosurgery Service and Gamma Knife Center.,4Faculty of Biology and Medicine, University of Lausanne, Switzerland
| | - Dimitri Van de Ville
- 8Medical Image Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland.,11University of Geneva, Faculty of Medicine, Geneva, Switzerland
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Fasano A, Helmich RC. Tremor habituation to deep brain stimulation: Underlying mechanisms and solutions. Mov Disord 2019; 34:1761-1773. [PMID: 31433906 DOI: 10.1002/mds.27821] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 07/01/2019] [Accepted: 07/18/2019] [Indexed: 12/14/2022] Open
Abstract
DBS of the ventral intermediate nucleus is an extremely effective treatment for essential tremor, although a waning benefit is observed after a variable time in a variable proportion of patients (ranging from 0% to 73%), a concept historically defined as "tolerance." Tolerance is currently an established concept in the medical community, although there is debate on its real existence. In fact, very few publications have actually addressed the problem, thus making tolerance a typical example of science based on "eminence rather than evidence." The underpinnings of the phenomena associated with the progressive loss of DBS benefit are not fully elucidated, although the interplay of different-not mutually exclusive-factors has been advocated. In this viewpoint, we gathered the evidence explaining the progressive loss of benefit observed after DBS. We grouped these factors in three categories: disease-related factors (tremor etiology and progression); surgery-related factors (electrode location, microlesional effect and placebo); and stimulation-related factors (not optimized stimulation, stimulation-induced side effects, habituation, and tremor rebound). We also propose possible pathophysiological explanations for the phenomenon and define a nomenclature of the associated features: early versus late DBS failure; tremor rebound versus habituation (to be preferred over tolerance). Finally, we provide a practical approach for preventing and treating this loss of DBS benefit, and we draft a possible roadmap for the research to come. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Alfonso Fasano
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada; Division of Neurology, University of Toronto, Toronto, Ontario, Canada.,Krembil Brain Institute, Toronto, Ontario, Canada.,CenteR for Advancing Neurotechnological Innovation to Application (CRANIA), Toronto, Ontario, Canada
| | - Rick C Helmich
- Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands
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Pedrosa DJ, Brown P, Cagnan H, Visser-Vandewalle V, Wirths J, Timmermann L, Brittain JS. A functional micro-electrode mapping of ventral thalamus in essential tremor. Brain 2019; 141:2644-2654. [PMID: 30052807 PMCID: PMC6113647 DOI: 10.1093/brain/awy192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/04/2018] [Indexed: 11/23/2022] Open
Abstract
Deep brain stimulation enables the delivery of therapeutic interventions to otherwise inaccessible areas of the brain while, at the same time, offering the unique opportunity to record from these same regions in awake patients. The posterior ventrolateral thalamus has become a reliable deep brain stimulation target for medically-refractory patients suffering from essential tremor. However, the contribution of the thalamus in essential tremor, and even whether posterior ventrolateral thalamus is the optimal target, remains a matter of ongoing debate. There are several lines of evidence supporting clusters of activity within the posterior ventrolateral thalamus that are important for tremor emergence. In this study we sought to map the functional properties of these clusters through microelectrode recordings during deep brain stimulation surgery. Data were obtained from 10 severely affected patients with essential tremor (12 hemispheres) undergoing deep brain stimulation surgery. Our results demonstrate power and coherence maxima located in the inferior posterior ventrolateral thalamus and immediate ventral region. Moreover, we identified distinct yet overlapping clusters of predominantly efferent (driving) and afferent (feedback) activity, with a preference for more efferent contributors, consistent with a net role in the driving of tremor output. Finally, we demonstrate that resolvable thalamic spiking activity directly relates to background activity and that the strength of tremor may be dictated by phase relationships between efferent and afferent pockets in the posterior ventrolateral thalamus. Taken together, these results provide important evidence for the role of the inferior posterior ventrolateral thalamus and its border region in essential tremor pathophysiology. Such results progress our mechanistic understanding and promote the adoption of next-generation therapies such as high resolution segregated deep brain stimulation electrodes.
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Affiliation(s)
- David J Pedrosa
- Department of Neurology, University Hospital of Marburg and Gießen, Marburg, Germany.,Nuffield Department of Clinical Neurosciences and MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK.,Department of Psychiatry, University Hospital of Marburg and Gießen, Marburg, Germany
| | - Peter Brown
- Nuffield Department of Clinical Neurosciences and MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Hayriye Cagnan
- Nuffield Department of Clinical Neurosciences and MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Veerle Visser-Vandewalle
- Department of Stereotactic and Functional Neurosurgery, University Hospital Cologne, Cologne, Germany
| | - Jochen Wirths
- Department of Stereotactic and Functional Neurosurgery, University Hospital Cologne, Cologne, Germany
| | - Lars Timmermann
- Department of Neurology, University Hospital of Marburg and Gießen, Marburg, Germany.,Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - John-Stuart Brittain
- Nuffield Department of Clinical Neurosciences and MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK.,School of Psychology, University of Birmingham, Birmingham, UK
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Tan H, Debarros J, He S, Pogosyan A, Aziz TZ, Huang Y, Wang S, Timmermann L, Visser-Vandewalle V, Pedrosa DJ, Green AL, Brown P. Decoding voluntary movements and postural tremor based on thalamic LFPs as a basis for closed-loop stimulation for essential tremor. Brain Stimul 2019; 12:858-867. [PMID: 30827864 PMCID: PMC6600875 DOI: 10.1016/j.brs.2019.02.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND High frequency Deep brain stimulation (DBS) targeting motor thalamus is an effective therapy for essential tremor (ET). However, conventional continuous stimulation may deliver unnecessary current to the brain since tremor mainly affects voluntary movements and sustained postures in ET. OBJECTIVE We aim to decode both voluntary movements and the presence of postural tremor from the Local field potentials (LFPs) recorded from the electrode implanted in motor thalamus for stimulation, in order to close the loop for DBS so that stimulation could be delivered on demand, without the need for peripheral sensors or additional invasive electrodes. METHODS LFPs from the motor thalamus, surface electromyographic (EMG) signals and/or behavioural measurements were simultaneously recorded in seven ET patients during temporary lead externalisation 3-5 days after the first surgery for DBS when they performed different voluntary upper limb movements. Nine different patients were recorded during the surgery, when they were asked to lift their arms to trigger postural tremor. A machine learning based binary classifier was used to detect voluntary movements and postural tremor based on features extracted from thalamic LFPs. RESULTS Cross-validation demonstrated that both voluntary movements and postural tremor can be decoded with an average sensitivity of 0.8 and false detection rate of 0.2. Oscillatory activities in the beta frequency bands (13-23 Hz) and the theta frequency bands (4-7 Hz) contributed most to the decoding of movements and postural tremor, respectively, though incorporating features in different frequency bands using a machine learning approach increased the accuracy of decoding.
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Affiliation(s)
- Huiling Tan
- Medical Research Council Brain Network Dynamics Unit at the University of Oxford, OX1 3TH, Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, Oxford, United Kingdom.
| | - Jean Debarros
- Medical Research Council Brain Network Dynamics Unit at the University of Oxford, OX1 3TH, Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, Oxford, United Kingdom
| | - Shenghong He
- Medical Research Council Brain Network Dynamics Unit at the University of Oxford, OX1 3TH, Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, Oxford, United Kingdom
| | - Alek Pogosyan
- Medical Research Council Brain Network Dynamics Unit at the University of Oxford, OX1 3TH, Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, Oxford, United Kingdom
| | - Tipu Z Aziz
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Yongzhi Huang
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Shouyan Wang
- Neural and Intelligence Engineering Center, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China
| | - Lars Timmermann
- Department of Neurology, University Hospital of Gießen and Marburg, Marburg, Germany
| | - Veerle Visser-Vandewalle
- Department of Stereotactic and Functional Neurosurgery, University Hospital Cologne, 50924, Cologne, Germany
| | - David J Pedrosa
- Department of Neurology, University Hospital of Gießen and Marburg, Marburg, Germany
| | - Alexander L Green
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Peter Brown
- Medical Research Council Brain Network Dynamics Unit at the University of Oxford, OX1 3TH, Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, Oxford, United Kingdom.
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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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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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Yi G, Grill WM. Frequency-dependent antidromic activation in thalamocortical relay neurons: effects of synaptic inputs. J Neural Eng 2018; 15:056001. [PMID: 29893711 DOI: 10.1088/1741-2552/aacbff] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Deep brain stimulation (DBS) generates action potentials (APs) in presynaptic axons and fibers of passage. The APs may be antidromically propagated to invade the cell body and/or orthodromically transmitted to downstream structures, thereby affecting widespread targets distant from the electrode. Activation of presynaptic terminals also causes trans-synaptic effects, which in turn alter the excitability of the post-synaptic neurons. Our aim was to determine how synaptic inputs affect the antidromic invasion of the cell body. APPROACH We used a biophysically-based multi-compartment model to simulate antidromic APs in thalamocortical relay (TC) neurons. We applied distributed synaptic inputs to the model and quantified how excitatory and inhibitory inputs contributed to the fidelity of antidromic activation over a range of antidromic frequencies. MAIN RESULTS Antidromic activation exhibited strong frequency dependence, which arose from the hyperpolarizing afterpotentials in the cell body and its respective recovery cycle. Low-frequency axonal spikes faithfully invaded the soma, whereas frequent failures of antidromic activation occurred at high frequencies. The frequency-dependent pattern of the antidromic activation masked burst-driver inputs to TC neurons from the cerebellum in a frequency-dependent manner. Antidromic activation also depended on the excitability of the cell body. Excitatory synaptic inputs improved the fidelity of antidromic activation by increasing the excitability, and inhibitory inputs suppressed antidromic activation by reducing soma excitability. Stimulus-induced depolarization of neuronal segments also facilitated antidromic propagation and activation. SIGNIFICANCE The results reveal that synaptic inputs, stimulus frequency, and electrode position regulate antidromic activation of the cell body during extracellular stimulation. These findings provide a biophysical basis for interpreting the widespread inhibition/activation of target nuclei during DBS.
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Affiliation(s)
- Guosheng Yi
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States of America. School of Electrical and Information Engineering, Tianjin University, Tianjin, People's Republic of China
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30
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Affiliation(s)
- Dietrich Haubenberger
- From the Clinical Trials Unit, Office of the Clinical Director (D.H.), and the Human Motor Control Section, Medical Neurology Branch (M.H.), National Institute of Neurological Disorders and Stroke Intramural Research Program, National Institutes of Health, Bethesda, MD
| | - Mark Hallett
- From the Clinical Trials Unit, Office of the Clinical Director (D.H.), and the Human Motor Control Section, Medical Neurology Branch (M.H.), National Institute of Neurological Disorders and Stroke Intramural Research Program, National Institutes of Health, Bethesda, MD
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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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Right Brodmann area 18 predicts tremor arrest after Vim radiosurgery: a voxel-based morphometry study. Acta Neurochir (Wien) 2018; 160:603-609. [PMID: 29128955 DOI: 10.1007/s00701-017-3391-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/02/2017] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Drug-resistant essential tremor (ET) can benefit from open standard stereotactic procedures, such as deep-brain stimulation or radiofrequency thalamotomy. Non-surgical candidates can be offered either high-focused ultrasound (HIFU) or radiosurgery (RS). All procedures aim to target the same thalamic site, the ventro-intermediate nucleus (e.g., Vim). The mechanisms by which tremor stops after Vim RS or HIFU remain unknown. We used voxel-based morphometry (VBM) on pretherapeutic neuroimaging data and assessed which anatomical site would best correlate with tremor arrest 1 year after Vim RS. METHODS Fifty-two patients (30 male, 22 female; mean age 71.6 years, range 49-82) with right-sided ET benefited from left unilateral Vim RS in Marseille, France. Targeting was performed in a uniform manner, using 130 Gy and a single 4-mm collimator. Neurological (pretherapeutic and 1 year after) and neuroimaging (baseline) assessments were completed. Tremor score on the treated hand (TSTH) at 1 year after Vim RS was included in a statistical parametric mapping analysis of variance (ANOVA) model as a continuous variable with pretherapeutic neuroimaging data. Pretherapeutic gray matter density (GMD) was further correlated with TSTH improvement. No a priori hypothesis was used in the statistical model. RESULTS The only statistically significant region was right Brodmann area (BA) 18 (visual association area V2, p = 0.05, cluster size Kc = 71). Higher baseline GMD correlated with better TSTH improvement at 1 year after Vim RS (Spearman's rank correlation coefficient = 0.002). CONCLUSIONS Routine baseline structural neuroimaging predicts TSTH improvement 1 year after Vim RS. The relevant anatomical area is the right visual association cortex (BA 18, V2). The question whether visual areas should be included in the targeting remains open.
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Tuleasca C, Régis J, Najdenovska E, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Cuadra MB, Levivier M, Van De Ville D. Pretherapeutic Functional Imaging Allows Prediction of Head Tremor Arrest After Thalamotomy for Essential Tremor: The Role of Altered Interconnectivity Between Thalamolimbic and Supplementary Motor Circuits. World Neurosurg 2018; 112:e479-e488. [PMID: 29410136 DOI: 10.1016/j.wneu.2018.01.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To correlate pretherapeutic resting-state functional magnetic resonance imaging (rs-fMRI) measures with pretherapeutic head tremor presence and/or further improvement 1 year after stereotactic radiosurgical thalamotomy (SRS-T) for essential tremor (ET). METHODS We prospectively collected head tremor scores (range, 0-3) and rs-fMRI data for a cohort of 17 consecutive ET patients in pretherapeutic and 1 year after SRS-T states. We additionally acquired rs-fMRI data for a healthy control (HC) group (n = 12). Group-level independent component analysis (n = 17 for pretherapeutic rs-fMRI) was applied to decompose neuroimaging data into 20 large-scale brain networks using a standard approach. Through spatial regression, we projected 1 year after SRS-T and HC rs-fMRI time points, on the same 20 brain networks. RESULTS Pretherapeutic interconnectivity (IC) strength between the network including bilateral thalamus and limbic system with left supplementary motor area predicted head tremor improvement at 1 year after SRS-T (family-wise corrected P < 0.001, cluster size Kc = 146). For the statistically significant cluster, IC strength was strongest in HCs (mean, 4.6; median, 3.8) compared with pre- (mean, 0.1; median, 0.2) or posttherapeutic (mean, -0.2; median, 0.09) states. CONCLUSIONS Baseline measures of IC between bilateral thalamus and limbic system with left supplementary motor area may predict head tremor arrest after thalamotomy. However, procedures such as SRS-T, for this particular clinical feature, do not align patients to HCs in terms of functional brain connectivity. We postulate that supplementary motor area is modulating head tremor appearance, by abnormal connectivity with the thalamolimbic system.
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Affiliation(s)
- Constantin Tuleasca
- Centre Hospitalier Universitaire Vaudois, Neurosurgery Service and Gamma Knife Center, Lausanne, Switzerland; Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
| | - Jean Régis
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, CHU Timone, Marseille, France
| | - Elena Najdenovska
- Medical Image Analysis Laboratory and Department of Radiology-Center of Biomedical Imaging, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | | | - Nadine Girard
- Department of Diagnostic and Interventional Neuroradiology, AMU, CRMBM UMR CNRS 7339, Faculté de Médecine et APHM, Hopital Timone, Marseille, France
| | - Jérôme Champoudry
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, CHU Timone, Marseille, France
| | - Mohamed Faouzi
- Centre for Clinical Epidemiology, Institute of Social and Preventive Medicine, Lausanne, Switzerland
| | - Jean-Philippe Thiran
- Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; Department of Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Meritxell Bach Cuadra
- Medical Image Analysis Laboratory and Department of Radiology-Center of Biomedical Imaging, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Marc Levivier
- Centre Hospitalier Universitaire Vaudois, Neurosurgery Service and Gamma Knife Center, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Dimitri Van De Ville
- Faculty of Medicine, University of Geneva, Geneva, Switzerland; Medical Image Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Filip P, Lungu OV, Manto MU, Bareš M. Linking Essential Tremor to the Cerebellum: Physiological Evidence. THE CEREBELLUM 2017; 15:774-780. [PMID: 26530223 DOI: 10.1007/s12311-015-0740-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Essential tremor (ET), clinically characterized by postural and kinetic tremors, predominantly in the upper extremities, originates from pathological activity in the dynamic oscillatory network comprising the majority of nodes in the central motor network. Evidence indicates dysfunction in the thalamus, the olivocerebellar loops, and intermittent cortical engagement. Pathology of the cerebellum, a structure with architecture intrinsically predisposed to oscillatory activity, has also been implicated in ET as shown by clinical, neuroimaging, and pathological studies. Despite electrophysiological studies assessing cerebellar impairment in ET being scarce, their impact is tangible, as summarized in this review. The electromyography-magnetoencephalography combination provided the first direct evidence of pathological alteration in cortico-subcortical communication, with a significant emphasis on the cerebellum. Furthermore, complex electromyography studies showed disruptions in the timing of agonist and antagonist muscle activation, a process generally attributed to the cerebellum. Evidence pointing to cerebellar engagement in ET has also been found in electrooculography measurements, cerebellar repetitive transcranial magnetic stimulation studies, and, indirectly, in complex analyses of the activity of the ventral intermediate thalamic nucleus (an area primarily receiving inputs from the cerebellum), which is also used in the advanced treatment of ET. In summary, further progress in therapy will require comprehensive electrophysiological and physiological analyses to elucidate the precise mechanisms leading to disease symptoms. The cerebellum, as a major node of this dynamic oscillatory network, requires further study to aid this endeavor.
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Affiliation(s)
- Pavel Filip
- First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Pekařská 53, 656 91, Brno, Czech Republic.,Central European Institute of Technology, CEITEC MU, Behavioral and Social Neuroscience Research Group, Masaryk University, Brno, Czech Republic
| | - Ovidiu V Lungu
- Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada.,Functional Neuroimaging Unit, Research Center of the Geriatric Institute Affiliated with the Université de Montréal, Montréal, Québec, Canada
| | | | - Martin Bareš
- First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Pekařská 53, 656 91, Brno, Czech Republic. .,Central European Institute of Technology, CEITEC MU, Behavioral and Social Neuroscience Research Group, Masaryk University, Brno, Czech Republic. .,Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA.
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Hirschmann J, Schoffelen JM, Schnitzler A, van Gerven MAJ. Parkinsonian rest tremor can be detected accurately based on neuronal oscillations recorded from the subthalamic nucleus. Clin Neurophysiol 2017; 128:2029-2036. [PMID: 28841506 DOI: 10.1016/j.clinph.2017.07.419] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/23/2017] [Accepted: 07/25/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate the possibility of tremor detection based on deep brain activity. METHODS We re-analyzed recordings of local field potentials (LFPs) from the subthalamic nucleus in 10 PD patients (12 body sides) with spontaneously fluctuating rest tremor. Power in several frequency bands was estimated and used as input to Hidden Markov Models (HMMs) which classified short data segments as either tremor-free rest or rest tremor. HMMs were compared to direct threshold application to individual power features. RESULTS Applying a threshold directly to band-limited power was insufficient for tremor detection (mean area under the curve [AUC] of receiver operating characteristic: 0.64, STD: 0.19). Multi-feature HMMs, in contrast, allowed for accurate detection (mean AUC: 0.82, STD: 0.15), using four power features obtained from a single contact pair. Within-patient training yielded better accuracy than across-patient training (0.84vs. 0.78, p=0.03), yet tremor could often be detected accurately with either approach. High frequency oscillations (>200Hz) were the best performing individual feature. CONCLUSIONS LFP-based markers of tremor are robust enough to allow for accurate tremor detection in short data segments, provided that appropriate statistical models are used. SIGNIFICANCE LFP-based markers of tremor could be useful control signals for closed-loop deep brain stimulation.
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Affiliation(s)
- J Hirschmann
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Germany.
| | - J M Schoffelen
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - A Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Germany; Center for Movement Disorders and Neuromodulation, Medical Faculty, University Hospital Düsseldorf, Germany
| | - M A J van Gerven
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
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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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Kobayashi K, Chien JH, Kim JH, Lenz FA. Sensory, Motor and Intrinsic Mechanisms of Thalamic Activity related to Organic and Psychogenic Dystonia. ACTA ACUST UNITED AC 2017; 7. [PMID: 28944096 PMCID: PMC5609466 DOI: 10.4172/2161-0460.1000324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The thalamus is a critical module in the circuit which has been associated with movement disorders including dystonia. This circuit extends from cortex to striatum to pallidum to the thalamic nucleus Ventral Lateral anterior (VLa) to cortex and can be studied by activity recorded during thalamic stereotactic surgery for the treatment of dystonia. Neuronal recordings in the VLa nucleus show low frequency modulation of firing that is correlated with and leads the low frequency modulation of EMG activity; this EMG activity is characteristic of dystonia. Immediately posterior is the Ventral Lateral posterior (VLp) nucleus which, in controls (patients with tremor or chronic pain), is characterized by deep sensory cells which fire at short latency in response to movement of a single joint or to stimulation of deep structures, such as muscles, tendons and joints. In patients with dystonia, neurons with this sensory activity are much more common than in controls and single neurons often respond to movement of multiple joints. In controls operated for the treatment of tremor or chronic pain many neurons in both nuclei are activated during active or involuntary joint movements, such as tremor or dystonia. The active joint movement related to the firing of a cell is usually in the opposite direction to the passive joint movement which causes that cell to fire. This linkage of active or involuntary and passive joint movement is unfocussed in dystonia. The involuntary dystonic joint movement best correlated with firing of a neuron may not activate the neuron when it occurs as a passive movement, while multiple other passive movements will activate the neuron. These linkages may explain the overflow of isolated voluntary activity to multiple other muscles that is seen in dystonia. The activity of either nucleus may have a critical role in dystonia since their disruption by stimulation or lesioning can decrease dystonia.
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Affiliation(s)
- K Kobayashi
- Departments of Neurosurgery and Neurology Johns Hopkins Hospital, Baltimore, MD, USA.,Division of Neurosurgery, Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan
| | - J H Chien
- Departments of Neurosurgery and Neurology Johns Hopkins Hospital, Baltimore, MD, USA
| | - J H Kim
- Departments of Neurosurgery and Neurology Johns Hopkins Hospital, Baltimore, MD, USA.,Department of Neurosurgery, Korea University Guro Hospital, Seoul, Korea
| | - F A Lenz
- Departments of Neurosurgery and Neurology Johns Hopkins Hospital, Baltimore, MD, USA
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Cagnan H, Pedrosa D, Little S, Pogosyan A, Cheeran B, Aziz T, Green A, Fitzgerald J, Foltynie T, Limousin P, Zrinzo L, Hariz M, Friston KJ, Denison T, Brown P. Stimulating at the right time: phase-specific deep brain stimulation. Brain 2017; 140:132-145. [PMID: 28007997 PMCID: PMC5226063 DOI: 10.1093/brain/aww286] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/30/2016] [Accepted: 09/18/2016] [Indexed: 11/13/2022] Open
Abstract
SEE MOLL AND ENGEL DOI101093/AWW308 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Brain regions dynamically engage and disengage with one another to execute everyday actions from movement to decision making. Pathologies such as Parkinson's disease and tremor emerge when brain regions controlling movement cannot readily decouple, compromising motor function. Here, we propose a novel stimulation strategy that selectively regulates neural synchrony through phase-specific stimulation. We demonstrate for the first time the therapeutic potential of such a stimulation strategy for the treatment of patients with pathological tremor. Symptom suppression is achieved by delivering stimulation to the ventrolateral thalamus, timed according to the patient's tremor rhythm. Sustained locking of deep brain stimulation to a particular phase of tremor afforded clinically significant tremor relief (up to 87% tremor suppression) in selected patients with essential tremor despite delivering less than half the energy of conventional high frequency stimulation. Phase-specific stimulation efficacy depended on the resonant characteristics of the underlying tremor network. Selective regulation of neural synchrony through phase-locked stimulation has the potential to both increase the efficiency of therapy and to minimize stimulation-induced side effects.
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Affiliation(s)
- Hayriye Cagnan
- 1 Institute of Neurology, University College London, London, UK
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- 3 Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - David Pedrosa
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- 3 Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Simon Little
- 1 Institute of Neurology, University College London, London, UK
| | - Alek Pogosyan
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- 3 Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Binith Cheeran
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Tipu Aziz
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Alexander Green
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - James Fitzgerald
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Thomas Foltynie
- 1 Institute of Neurology, University College London, London, UK
| | | | - Ludvic Zrinzo
- 1 Institute of Neurology, University College London, London, UK
| | - Marwan Hariz
- 1 Institute of Neurology, University College London, London, UK
| | - Karl J Friston
- 1 Institute of Neurology, University College London, London, UK
| | | | - Peter Brown
- 2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- 3 Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
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Knowledge gaps and research recommendations for essential tremor. Parkinsonism Relat Disord 2016; 33:27-35. [PMID: 27769649 DOI: 10.1016/j.parkreldis.2016.10.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 08/29/2016] [Accepted: 10/01/2016] [Indexed: 12/17/2022]
Abstract
Essential tremor (ET) is a common cause of significant disability, but its etiologies and pathogenesis are poorly understood. Research has been hampered by the variable definition of ET and by non-standardized research approaches. The National Institute of Neurological Disorders and Stroke (USA) invited experts in ET and related fields to discuss current knowledge, controversies, and gaps in our understanding of ET and to develop recommendations for future research. Discussion focused on phenomenology and phenotypes, therapies and clinical trials, pathophysiology, pathology, and genetics. Across all areas, the need for collaborative and coordinated research on a multinational level was expressed. Standardized data collection using common data elements for genetic, clinical, neurophysiological, and pathological studies was recommended. Large cohorts of patients should be studied prospectively to collect bio-samples, characterize the natural history of the clinical syndrome including patient-oriented outcomes, investigate potential etiologies of various phenotypes, and identify pathophysiological mechanisms. In particular, cellular and system-level mechanisms of tremor oscillations should be elucidated because they may yield effective therapeutic targets and biomarkers. A neuropathology consortium was recommended to standardize postmortem analysis and further characterize neuropathological observations in the cerebellum and elsewhere. Furthermore, genome-wide association studies on large patient cohorts (>10,000 patients) may allow the identification of common genes contributing to risk, and whole exome or genome sequencing may enable the identification of genetic risk and causal mutations in cohorts and well-characterized families.
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40
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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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Couto J, Grill WM. Kilohertz Frequency Deep Brain Stimulation Is Ineffective at Regularizing the Firing of Model Thalamic Neurons. Front Comput Neurosci 2016; 10:22. [PMID: 27014047 PMCID: PMC4791372 DOI: 10.3389/fncom.2016.00022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/29/2016] [Indexed: 01/24/2023] Open
Abstract
Deep brain stimulation (DBS) is an established therapy for movement disorders, including tremor, dystonia, and Parkinson's disease, but the mechanisms of action are not well understood. Symptom suppression by DBS typically requires stimulation frequencies ≥100 Hz, but when the frequency is increased above ~2 kHz, the effectiveness in tremor suppression declines (Benabid et al., 1991). We sought to test the hypothesis that the decline in efficacy at high frequencies is associated with desynchronization of the activity generated within a population of stimulated neurons. Regularization of neuronal firing is strongly correlated with tremor suppression by DBS, and desynchronization would disrupt the regularization of neuronal activity. We implemented computational models of CNS axons with either deterministic or stochastic membrane dynamics, and quantified the response of populations of model nerve fibers to extracellular stimulation at different frequencies and amplitudes. As stimulation frequency was increased from 2 to 80 Hz the regularity of neuronal firing increased (as assessed with direct estimates of entropy), in accord with the clinical effects on tremor of increasing stimulation frequency (Kuncel et al., 2006). Further, at frequencies between 80 and 500 Hz, increasing the stimulation amplitude (i.e., the proportion of neurons activated by the stimulus) increased the regularity of neuronal activity across the population, in accord with the clinical effects on tremor of stimulation amplitude (Kuncel et al., 2007). However, at stimulation frequencies above 1 kHz the regularity of neuronal firing declined due to irregular patterns of action potential generation and conduction block. The reductions in neuronal regularity that occurred at high frequencies paralleled the previously reported decline in tremor reduction and may be responsible for the loss of efficacy of DBS at very high frequencies. This analysis provides further support for the hypothesis that effective DBS masks the intrinsic patterns of activity in the stimulated neurons and replaces it with regularized firing.
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Affiliation(s)
- João Couto
- Department of Biomedical Engineering, Duke UniversityDurham, NC, USA; Theoretical Neurobiology and Neuroengineering Laboratory, Department of Biomedical Engineering, University of AntwerpAntwerp, Belgium
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University Durham, NC, USA
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He F, Sarrigiannis PG, Billings SA, Wei H, Rowe J, Romanowski C, Hoggard N, Hadjivassilliou M, Rao DG, Grünewald R, Khan A, Yianni J. Nonlinear interactions in the thalamocortical loop in essential tremor: A model-based frequency domain analysis. Neuroscience 2016; 324:377-89. [PMID: 26987955 DOI: 10.1016/j.neuroscience.2016.03.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/21/2016] [Accepted: 03/08/2016] [Indexed: 10/22/2022]
Abstract
There is increasing evidence to suggest that essential tremor has a central origin. Different structures appear to be part of the central tremorogenic network, including the motor cortex, the thalamus and the cerebellum. Some studies using electroencephalogram (EEG) and magnetoencephalography (MEG) show linear association in the tremor frequency between the motor cortex and the contralateral tremor electromyography (EMG). Additionally, high thalamomuscular coherence is found with the use of thalamic local field potential (LFP) recordings and tremulous EMG in patients undergoing surgery for deep brain stimulation (DBS). Despite a well-established reciprocal anatomical connection between the thalamus and cortex, the functional association between the two structures during "tremor-on" periods remains elusive. Thalamic (Vim) LFPs, ipsilateral scalp EEG from the sensorimotor cortex and contralateral tremor arm EMG recordings were obtained from two patients with essential tremor who had undergone successful surgery for DBS. Coherence analysis shows a strong linear association between thalamic LFPs and contralateral tremor EMG, but the relationship between the EEG and the thalamus is much less clear. These measurements were then analyzed by constructing a novel parametric nonlinear autoregressive with exogenous input (NARX) model. This new approach uncovered two distinct and not overlapping frequency "channels" of communication between Vim thalamus and the ipsilateral motor cortex, defining robustly "tremor-on" versus "tremor-off" states. The associated estimated nonlinear time lags also showed non-overlapping values between the two states, with longer corticothalamic lags (exceeding 50ms) in the tremor active state, suggesting involvement of an indirect multisynaptic loop. The results reveal the importance of the nonlinear interactions between cortical and subcortical areas in the central motor network of essential tremor. This work is important because it demonstrates for the first time that in essential tremor the functional interrelationships between the cortex and thalamus should not be sought exclusively within individual frequencies but more importantly between cross-frequency nonlinear interactions. Should our results be successfully reproduced on a bigger cohort of patients with essential tremor, our approach could be used to create an on-demand closed-loop DBS device, able to automatically activate when the tremor is on.
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Affiliation(s)
- F He
- Department of Automatic Control and Systems Engineering, University of Sheffield, S1 3JD, United Kingdom.
| | - P G Sarrigiannis
- Department of Clinical Neurophysiology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - S A Billings
- Department of Automatic Control and Systems Engineering, University of Sheffield, S1 3JD, United Kingdom.
| | - H Wei
- Department of Automatic Control and Systems Engineering, University of Sheffield, S1 3JD, United Kingdom.
| | - J Rowe
- Department of Neurosurgery, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - C Romanowski
- Department of Radiology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - N Hoggard
- Department of Radiology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - M Hadjivassilliou
- Department of Neurology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - D G Rao
- Department of Clinical Neurophysiology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - R Grünewald
- Department of Neurology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - A Khan
- Department of Neurology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
| | - J Yianni
- Department of Neurosurgery, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield S10 2JF, United Kingdom.
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43
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Rodríguez Cruz PM, Vargas A, Fernández-Carballal C, Garbizu J, De La Casa-Fages B, Grandas F. Long-term Thalamic Deep Brain Stimulation for Essential Tremor: Clinical Outcome and Stimulation Parameters. Mov Disord Clin Pract 2016; 3:567-572. [PMID: 30363558 DOI: 10.1002/mdc3.12337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/25/2015] [Accepted: 01/04/2016] [Indexed: 11/09/2022] Open
Abstract
Background The reasons underlying the loss of efficacy of deep brain stimulation (DBS) of the thalamic nucleus ventralis intermedius (VIM-DBS) over time in patients with essential tremor are not well understood. Methods Long-term clinical outcome and stimulation parameters were evaluated in 14 patients with essential tremor who underwent VIM-DBS. The mean ± standard deviation postoperative follow-up was 7.7 ± 3.8 years. At each visit (every 3-6 months), tremor was assessed using the Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) and stimulation parameters were recorded (contacts, voltage, frequency, pulse width, and total electrical energy delivered by the internal generator [TEED 1sec]). Results The mean reduction in FTM-TRS score was 73.4% at 6 months after VIM-DBS surgery (P < 0.001) and 50.1% at the last visit (P < 0.001). The gradual worsening of FTM-TRS scores over time fit a linear regression model (coefficient of determination [R2] = 0.887; P < 0.001). Stimulation adjustments to optimize tremor control required a statistically significant increase in voltage (P = 0.01), pulse width (P = 0.01), frequency (P = 0.02), and TEED 1sec (P = 0.008). TEED 1sec fit a third-order polynomial curve model throughout the follow-up period (R2 = 0.966; P < 0.001). The initial exponential increase (first 4 years of VIM-DBS) was followed by a plateau and a further increase from the seventh year onward. Conclusions The current findings suggest that the waning effect of VIM-DBS over time in patients with essential tremor may be the consequence of a combination of factors. Superimposed on the progression of the disease, tolerance can occur during the early years of stimulation.
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Affiliation(s)
- Pedro M Rodríguez Cruz
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Antonio Vargas
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Carlos Fernández-Carballal
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Jose Garbizu
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Beatriz De La Casa-Fages
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Francisco Grandas
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
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Herrington TM, Cheng JJ, Eskandar EN. Mechanisms of deep brain stimulation. J Neurophysiol 2015; 115:19-38. [PMID: 26510756 DOI: 10.1152/jn.00281.2015] [Citation(s) in RCA: 287] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 10/22/2015] [Indexed: 12/31/2022] Open
Abstract
Deep brain stimulation (DBS) is widely used for the treatment of movement disorders including Parkinson's disease, essential tremor, and dystonia and, to a lesser extent, certain treatment-resistant neuropsychiatric disorders including obsessive-compulsive disorder. Rather than a single unifying mechanism, DBS likely acts via several, nonexclusive mechanisms including local and network-wide electrical and neurochemical effects of stimulation, modulation of oscillatory activity, synaptic plasticity, and, potentially, neuroprotection and neurogenesis. These different mechanisms vary in importance depending on the condition being treated and the target being stimulated. Here we review each of these in turn and illustrate how an understanding of these mechanisms is inspiring next-generation approaches to DBS.
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Affiliation(s)
- Todd M Herrington
- Nayef Al-Rodhan Laboratories, Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; and
| | - Jennifer J Cheng
- Nayef Al-Rodhan Laboratories, Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, Maryland
| | - Emad N Eskandar
- Nayef Al-Rodhan Laboratories, Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Swan BD, Brocker DT, Hilliard JD, Tatter SB, Gross RE, Turner DA, Grill WM. Short pauses in thalamic deep brain stimulation promote tremor and neuronal bursting. Clin Neurophysiol 2015; 127:1551-1559. [PMID: 26330131 DOI: 10.1016/j.clinph.2015.07.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 07/01/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE We conducted intraoperative measurements of tremor during DBS containing short pauses (⩽50 ms) to determine if there is a minimum pause duration that preserves tremor suppression. METHODS Nine subjects with ET and thalamic DBS participated during IPG replacement surgery. Patterns of DBS included regular 130 Hz stimulation interrupted by 0, 15, 25 or 50 ms pauses. The same patterns were applied to a model of the thalamic network to quantify effects of pauses on activity of model neurons. RESULTS All patterns of DBS decreased tremor relative to 'off'. Patterns with pauses generated less tremor reduction than regular high frequency DBS. The model revealed that rhythmic burst-driver inputs to thalamus were masked during DBS, but pauses in stimulation allowed propagation of bursting activity. The mean firing rate of bursting-type model neurons as well as the firing pattern entropy of model neurons were both strongly correlated with tremor power across stimulation conditions. CONCLUSIONS The temporal pattern of stimulation influences the efficacy of thalamic DBS. Pauses in stimulation resulted in decreased tremor suppression indicating that masking of pathological bursting is a mechanism of thalamic DBS for tremor. SIGNIFICANCE Pauses in stimulation decreased the efficacy of open-loop DBS for suppression of tremor.
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Affiliation(s)
- Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - David T Brocker
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Justin D Hilliard
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Stephen B Tatter
- Department of Neurosurgery, Wake Forest University Baptist Medical Center, Winston-Salem, NC, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Dennis A Turner
- Department of Surgery, Duke University Medical Center, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Surgery, Duke University Medical Center, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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The phase difference between neural drives to antagonist muscles in essential tremor is associated with the relative strength of supraspinal and afferent input. J Neurosci 2015; 35:8925-37. [PMID: 26063924 DOI: 10.1523/jneurosci.0106-15.2015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The pathophysiology of essential tremor (ET), the most common movement disorder, is not fully understood. We investigated which factors determine the variability in the phase difference between neural drives to antagonist muscles, a long-standing observation yet unexplained. We used a computational model to simulate the effects of different levels of voluntary and tremulous synaptic input to antagonistic motoneuron pools on the tremor. We compared these simulations to data from 11 human ET patients. In both analyses, the neural drive to muscle was represented as the pooled spike trains of several motor units, which provides an accurate representation of the common synaptic input to motoneurons. The simulations showed that, for each voluntary input level, the phase difference between neural drives to antagonist muscles is determined by the relative strength of the supraspinal tremor input to the motoneuron pools. In addition, when the supraspinal tremor input to one muscle was weak or absent, Ia afferents provided significant common tremor input due to passive stretch. The simulations predicted that without a voluntary drive (rest tremor) the neural drives would be more likely in phase, while a concurrent voluntary input (postural tremor) would lead more frequently to an out-of-phase pattern. The experimental results matched these predictions, showing a significant change in phase difference between postural and rest tremor. They also indicated that the common tremor input is always shared by the antagonistic motoneuron pools, in agreement with the simulations. Our results highlight that the interplay between supraspinal input and spinal afferents is relevant for tremor generation.
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Ho AL, Erickson-Direnzo E, Pendharkar AV, Sung CK, Halpern CH. Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology. Neurosurg Focus 2015; 38:E6. [DOI: 10.3171/2015.3.focus1537] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors’ knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.
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Affiliation(s)
| | | | | | - Chih-Kwang Sung
- 2Otolaryngology (Head and Neck Surgery), Stanford University School of Medicine, Stanford, California
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Kim JH, Chien JH, Liu CC, Lenz FA. Painful cutaneous laser stimuli induce event-related gamma-band activity in the lateral thalamus of humans. J Neurophysiol 2015; 113:1564-73. [PMID: 25505116 PMCID: PMC4346717 DOI: 10.1152/jn.00778.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/09/2014] [Indexed: 11/22/2022] Open
Abstract
Although the thalamus is an important module in "pain networks," there are few studies of the effect of experimental pain upon thalamic oscillations. We have now examined the hypothesis that, during a series of painful cutaneous laser stimuli, thalamic signals will show stimulus-related gamma-band spectral activity, which is modulated by attention to vs. distraction from the painful stimulus. When the series of laser stimuli was presented, attention was focused by counting the laser stimuli (count laser task), while distraction was produced by counting backward (count back plus laser task). We have studied the effect of a cutaneous laser on thalamic local field potentials and EEG activity during awake procedures (deep brain stimulation implants) for the treatment of essential tremor. At different delays after the stimulus, three low gamma- (30-50 Hz) and two high gamma-band (70-90 Hz) activations were observed during the two tasks. Greater high-gamma activation was found during the count laser task for the earlier window, while greater high-gamma activation was found during the count back plus laser task for the later window. Thalamic signals were coherent with EEG signals in the beta band, which indicated significant synchrony. Thalamic cross-frequency coupling analysis indicated that the phase of the lower frequency activity (theta to beta) modulated the amplitude of the higher frequency activity (low and high gamma) more strongly during the count laser task than during the count back plus laser task. This modulation might result in multiplexed signals each encoding a different aspect of pain.
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Affiliation(s)
- J H Kim
- Department of Neurosurgery, Korea University, Guro Hospital, Seoul, South Korea
| | - J H Chien
- Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland; and
| | - C C Liu
- Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland; and
| | - F A Lenz
- Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland; and
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Morphometric and functional MRI changes in essential tremor with and without resting tremor. J Neurol 2015; 262:719-28. [PMID: 25572161 DOI: 10.1007/s00415-014-7626-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/02/2014] [Accepted: 12/22/2014] [Indexed: 12/17/2022]
Abstract
The etiopathogenesis of essential tremor (ET) is still debated, since the predominant role of circuit dysfunction or brain degenerative changes has not been clearly established. The relationship with Parkinson's Disease (PD) is also controversial and resting tremor occurs in up to 20 % of ET. We investigated the morphological and functional changes associated with ET and we assessed potential differences related to the presence (ET+R) or absence (ET-R) of resting tremor. 32 ET patients (18 ET+R; 14 ET-R) and 12 healthy controls (HC) underwent 3T-MRI protocol including Spoiled Gradient T1-weighted sequence for Voxel-Based Morphometry (VBM) analysis and functional MRI during continuous writing of "8" with right dominant hand. VBM analysis revealed no gray and white matter atrophy comparing ET patients to HC and ET+R to ET-R patients. HC showed a higher BOLD response with respect to ET patients in cerebellum and other brain areas pertaining to cerebello-thalamo-cortical circuit. Between-group activation maps showed higher activation in precentral gyrus bilaterally, right superior and inferior frontal gyri, left postcentral gyrus, superior and inferior parietal gyri, mid temporal and supramarginal gyri, cerebellum and internal globus pallidus in ET-R compared to ET+R patients. Our findings support that the dysfunction of cerebello-thalamo-cortical network is associated with ET in absence of any morphometric changes. The dysfunction of GPi in ET+R patients, consistently with data reported in PD resting tremor, might suggest a potential role of this structure in this type of tremor.
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