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Benarroch E. What Is the Role of the Dentate Nucleus in Normal and Abnormal Cerebellar Function? Neurology 2024; 103:e209636. [PMID: 38954796 DOI: 10.1212/wnl.0000000000209636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
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2
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Prasad S, Saini J, Bharath RD, Pal PK. Differential patterns of functional connectivity in tremor dominant Parkinson's disease and essential tremor plus. J Neural Transm (Vienna) 2024; 131:781-789. [PMID: 38430265 DOI: 10.1007/s00702-024-02761-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 02/23/2024] [Indexed: 03/03/2024]
Abstract
Tremor dominant Parkinson's disease (TDPD) and essential tremor plus (ETP) syndrome are commonly encountered tremor dominant neurological disorders. Although the basal ganglia thalamocortical (BGTC) and cerebello thalamocortical (CTC) networks are implicated in tremorogenesis, the extent of functional connectivity alterations across disorders is uncertain. This study aims to evaluate functional connectivity of the BGTC and CTC in TDPD and ETP. Resting state functional MRI was acquired for 25 patients with TDPD, ETP and 22 healthy controls (HC). Following pre-processing and denoising, seed-to-voxel based connectivity was carried out at FDR < 0.05 using ROIs belonging to the BGTC and CTC. Fahn-Tolosa-Marin tremor rating scale (FTMRS) was correlated with the average connectivity values at FDR < 0.05. Compared to HC, TDPD showed decreased connectivity between cerebellum and pre, post central gyrus. While, ETP showed decreased connectivity between pallidum and occipital cortex, precuneus, cuneus compared to HC. In comparison to ETP, TDPD showed increased connectivity between precentral gyrus, pallidum, SNc with the default mode network (DMN), and decreased connectivity between cerebellum with superior, middle frontal gyrus was observed. Tremor severity positively correlated with connectivity between SNc and DMN in TDPD, and negatively correlated with pallidal connectivity in ETP. Pattern of BGTC, CTC involvement is differential i.e., higher connectivity of the BGTC nodes in TDPD, and higher connectivity of cerebellar nodes in ETP. The interesting observation of pallidal involvement in ETP suggests the role of BGTC in the pathogenesis of ETP, and indicated similarities in concepts of tremor genesis in TDPD and ETP.
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Affiliation(s)
- Shweta Prasad
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Jitender Saini
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka, 560029, India.
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Yang Y, Zheng C, Chen B, Hernandez NC, Faust PL, Cai Z, Louis ED, Matuskey D. Decreased Synaptic Vesicle Glycoprotein 2A Binding in the Human Postmortem Essential Tremor Cerebellum: Evidence of Reduction in Synaptic Density. CEREBELLUM (LONDON, ENGLAND) 2024; 23:1053-1060. [PMID: 37783917 DOI: 10.1007/s12311-023-01611-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/27/2023] [Indexed: 10/04/2023]
Abstract
OBJECTIVE Despite being one of the most prevalent neurological diseases, the pathophysiology of essential tremor (ET) is not fully understood. Neuropathological studies have identified numerous degenerative changes in the cerebellum of ET patients, however. These data align with considerable clinical and neurophysiological data linking ET to the cerebellum. While neuroimaging studies have variably shown mild atrophy in the cerebellum, marked atrophy is not a clear feature of the cerebellum in ET and a search for a more suitable neuroimaging signature of neurodegeneration is in order. Postmortem studies in ET have examined different neuropathological alterations in the cerebellum, but as of yet have not focused on measures of generalized synaptic markers. This pilot study focuses on synaptic vesicle glycoprotein 2A (SV2A), a protein expressed in practically all synapses in the brain, as a measure of synaptic density in postmortem ET cases. METHODS The current study utilized autoradiography with the SV2A radioligand [18F]SDM-16 to assess synaptic density in the cerebellar cortex and dentate nucleus in three ET cases and three age-matched controls. RESULTS Using [18F]SDM-16, SV2A was 53% and 46% lower in the cerebellar cortex and dentate nucleus, respectively, in ET cases compared to age-matched controls. CONCLUSION In this pilot study, using in vitro SV2A autoradiography, we have observed significantly lower synaptic density in the cerebellar cortex and dentate nucleus of ET cases. Future research could expand on our sample size and focus on in vivo imaging in ET to explore whether SV2A imaging could serve as a much-needed disease biomarker.
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Affiliation(s)
- Yanghong Yang
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Chao Zheng
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Baosheng Chen
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Nora C Hernandez
- Department of Neurology, University of Texas Southwestern School of Medicine, Dallas, TX, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital, New York, NY, USA
| | - Zhengxin Cai
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern School of Medicine, Dallas, TX, USA
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.
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4
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Passaretti M, Piervincenzi C, Baione V, Pasqua G, Colella D, Pietracupa S, Petsas N, Angelini L, Cannavacciuolo A, Paparella G, Berardelli A, Pantano P, Bologna M. The Role of Cerebellum and Basal Ganglia Functional Connectivity in Altered Voluntary Movement Execution in Essential Tremor. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01699-6. [PMID: 38761352 DOI: 10.1007/s12311-024-01699-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/25/2024] [Indexed: 05/20/2024]
Abstract
Substantial evidence highlights the role of the cerebellum in the pathophysiology of tremor in essential tremor (ET), although its potential involvement in altered movement execution in this condition remains unclear. This study aims to explore potential correlations between the cerebellum and basal ganglia functional connectivity and voluntary movement execution abnormalities in ET, objectively assessed with kinematic techniques. A total of 20 patients diagnosed with ET and 18 healthy subjects were enrolled in this study. Tremor and repetitive finger tapping were recorded using an optoelectronic kinematic system. All participants underwent comprehensive 3T-MRI examinations, including 3D-T1 and blood-oxygen-level dependent (BOLD) sequences during resting state. Morphometric analysis was conducted on the 3D-T1 images, while a seed-based analysis was performed to investigate the resting-state functional connectivity (rsFC) of dorsal and ventral portions of the dentate nucleus and the external and internal segments of the globus pallidus. Finally, potential correlations between rsFC alterations in patients and clinical as well as kinematic scores were assessed. Finger tapping movements were slower in ET than in healthy subjects. Compared to healthy subjects, patients with ET exhibited altered FC of both dentate and globus pallidus with cerebellar, basal ganglia, and cortical areas. Interestingly, both dentate and pallidal FC exhibited positive correlations with movement velocity in patients, differently from that we observed in healthy subjects, indicating the higher the FC, the faster the finger tapping. The findings of this study indicate the possible role of both cerebellum and basal ganglia in the pathophysiology of altered voluntary movement execution in patients with ET.
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Affiliation(s)
- Massimiliano Passaretti
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Claudia Piervincenzi
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
| | - Viola Baione
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Gabriele Pasqua
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
| | - Donato Colella
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
| | - Sara Pietracupa
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Nikolaos Petsas
- Department of Public Health and Infectious Disease, Sapienza University of Rome, Rome, Italy
| | | | | | - Giulia Paparella
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Patrizia Pantano
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy.
- IRCCS Neuromed, Pozzilli, IS, Italy.
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Rios-Zermeno J, Ballesteros-Herrera D, Dominguez-Vizcayno P, Carrillo-Ruiz JD, Moreno-Jimenez S. Dentate nucleus: a review and implications for dentatotomy. Acta Neurochir (Wien) 2024; 166:219. [PMID: 38758379 DOI: 10.1007/s00701-024-06104-z] [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: 02/27/2024] [Accepted: 04/27/2024] [Indexed: 05/18/2024]
Abstract
PURPOSE The dentate nucleus (DN) is the largest, most lateral, and phylogenetically most recent of the deep cerebellar nuclei. Its pivotal role encompasses the planning, initiation, and modification of voluntary movement but also spans non-motor functions like executive functioning, visuospatial processing, and linguistic abilities. This review aims to offer a comprehensive description of the DN, detailing its embryology, anatomy, physiology, and clinical relevance, alongside an analysis of dentatotomy. METHODS AND RESULTS We delve into the history, embryology, anatomy, vascular supply, imaging characteristics, and clinical significance of the DN. Furthermore, we thoroughly review the dentatotomy, emphasizing its role in treating spasticity. CONCLUSIONS Understanding the intricacies of the anatomy, physiology, vasculature, and projections of the DN has taken on increased importance in current neurosurgical practice. Advances in technology have unveiled previously unknown functions of the deep cerebellar nuclei, predominantly related to non-motor domains. Such discoveries are revitalizing older techniques, like dentatotomy, and applying them to newer, more localized targets.
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Affiliation(s)
- Jorge Rios-Zermeno
- Department of Neurosurgery, Instituto Nacional de Neurologia y Neurocirugia, Av Insurgentes Sur 3877, Tlalpan, Mexico City, Mexico
| | - Daniel Ballesteros-Herrera
- Department of Neurosurgery, Instituto Nacional de Neurologia y Neurocirugia, Av Insurgentes Sur 3877, Tlalpan, Mexico City, Mexico
| | - Pamela Dominguez-Vizcayno
- Department of Radioneurosurgery, Instituto Nacional de Neurologia y Neurocirugia, Mexico City, Mexico
| | - José Damián Carrillo-Ruiz
- Research Direction & Stereotactic and Functional Neurosurgery, Mexico General Hospital, Mexico City, Mexico
- Neuroscience CoordinationPschycology Faculty, Mexico Anahuac University, Mexico City, Mexico
| | - Sergio Moreno-Jimenez
- Department of Neurosurgery, Instituto Nacional de Neurologia y Neurocirugia, Av Insurgentes Sur 3877, Tlalpan, Mexico City, Mexico.
- Neurological Center, American British Cowdray Medical Center, Mexico City, Mexico.
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van der Stouwe AMM. Lack of effect of deep brain stimulation on resting-state functional connectivity in essential tremor provides valuable insights. Brain Commun 2024; 6:fcae060. [PMID: 38482374 PMCID: PMC10935647 DOI: 10.1093/braincomms/fcae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 02/19/2024] [Accepted: 02/27/2024] [Indexed: 05/02/2024] Open
Abstract
This scientific commentary refers to 'Deep brain stimulation does not modulate resting-state functional connectivity in essential tremor', by Awad et al. (https://doi.org/10.1093/braincomms/fcae012).
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Affiliation(s)
- A M Madelein van der Stouwe
- Department of Neurology, University Medical Center Groningen, 9700 RB Groningen, the Netherlands
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, 9700 RB Groningen, the Netherlands
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Sharifi S, Buijink AWG, Luft F, Scheijbeler EP, Potters WV, van Wingen G, Heida T, Bour LJ, van Rootselaar AF. Differences in Olivo-Cerebellar Circuit and Cerebellar Network Connectivity in Essential Tremor: a Resting State fMRI Study. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1123-1136. [PMID: 36214998 PMCID: PMC10657290 DOI: 10.1007/s12311-022-01486-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
The olivo-cerebellar circuit is thought to play a crucial role in the pathophysiology of essential tremor (ET). Whether olivo-cerebellar circuit dysfunction is also present at rest, in the absence of clinical tremor and linked voluntary movement, remains unclear. Assessing this network in detail with fMRI is challenging, considering the brainstem is close to major arteries and pulsatile cerebrospinal fluid-filled spaces obscuring signals of interest. Here, we used methods tailored to the analysis of infratentorial structures. We hypothesize that the olivo-cerebellar circuit shows altered intra-network connectivity at rest and decreased functional coupling with other parts of the motor network in ET. In 17 ET patients and 19 healthy controls, we investigated using resting state fMRI intracerebellar functional and effective connectivity on a dedicated cerebellar atlas. With independent component analysis, we investigated data-driven cerebellar motor network activations during rest. Finally, whole-brain connectivity of cerebellar motor structures was investigated using identified components. In ET, olivo-cerebellar pathways show decreased functional connectivity compared with healthy controls. Effective connectivity analysis showed an increased inhibitory influence of the dentate nucleus towards the inferior olive. Cerebellar independent component analyses showed motor resting state networks are less strongly connected to the cerebral cortex compared to controls. Our results indicate the olivo-cerebellar circuit to be affected at rest. Also, the cerebellum is "disconnected" from the rest of the motor network. Aberrant activity, generated within the olivo-cerebellar circuit could, during action, spread towards other parts of the motor circuit and potentially underlie the characteristic tremor of this patient group.
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Affiliation(s)
- Sarvi Sharifi
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands.
| | - Arthur W G Buijink
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Frauke Luft
- Department of Biomedical Signals and Systems, University of Twente, TechMed Centre, Enschede, The Netherlands
| | - Elliz P Scheijbeler
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location Vrije Universiteit Amsterdam, Boelelaan 1117, Amsterdam, The Netherlands
| | - Wouter V Potters
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Guido van Wingen
- Department of Psychiatry, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Tjitske Heida
- Department of Biomedical Signals and Systems, University of Twente, TechMed Centre, Enschede, The Netherlands
| | - Lo J Bour
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
| | - Anne-Fleur van Rootselaar
- Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, D2-113, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands
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Blondiaux F, Lebrun L, Hanseeuw BJ, Crevecoeur F. Impairments of saccadic and reaching adaptation in essential tremor are linked to movement execution. J Neurophysiol 2023; 130:1092-1102. [PMID: 37791388 DOI: 10.1152/jn.00165.2023] [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: 04/25/2023] [Revised: 09/05/2023] [Accepted: 09/27/2023] [Indexed: 10/05/2023] Open
Abstract
Essential tremor (ET) is a neurological disorder characterized by involuntary oscillations of the limbs. Previous studies have hypothesized that ET is a cerebellar disorder and reported impairments in motor adaptation. However, recent advances have highlighted that motor adaptation involves several components linked to anticipation and control, all dependent on cerebellum. We studied the contribution of both components in adaptation to better understand the adaptation impairments observed in ET from a behavioral perspective. To address this question, we investigated behavioral markers of adaptation in ET patients (n = 20) and age-matched neurologically intact volunteers (n = 20) in saccadic and upper limb adaptation tasks, probing compensation for target jumps and for velocity-dependent force fields, respectively. We found that both groups adapted their movements to the novel contexts; however, ET patients adapted to a lesser extent compared with neurologically intact volunteers. Importantly, components of the movement linked to anticipation were preserved in the ET group, whereas components linked to movement execution appeared responsible for the adaptation deficit in this group. Altogether, our results suggest that execution deficits may be a specific functional consequence of the alteration of neural pathways associated with ET.NEW & NOTEWORTHY We tested essential tremor patients' adaptation abilities in classical tasks including saccadic adaptation to target jumps and reaching adaptation to force field disturbances. Patients' adaptation was present but impaired in both tasks. Interestingly, the deficits were mainly present during movement execution, whereas the anticipatory components of movements were similar to neurologically intact volunteers. These findings reinforce the hypothesis of a cerebellar origin for essential tremor and detail the motor adaptation impairments previously found in this disorder.
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Affiliation(s)
- Florence Blondiaux
- Institute for Information and Communication Technologies, Electronics and Applied Mathematics, UCLouvain, Louvain-la-Neuve, Belgium
- Institute of Neuroscience, UCLouvain, Brussels, Belgium
| | - Louisien Lebrun
- Institute of Neuroscience, UCLouvain, Brussels, Belgium
- Neurology Department, Saint-Luc University Hospital, Brussels, Belgium
| | - Bernard J Hanseeuw
- Institute of Neuroscience, UCLouvain, Brussels, Belgium
- Neurology Department, Saint-Luc University Hospital, Brussels, Belgium
- Gordon Center for Medical Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Louvain Aging Brain Lab, Walloon Excellence in Life Sciences and Biotechnology (WELBIO), UCLouvain, Brussels, Belgium
| | - Frédéric Crevecoeur
- Institute for Information and Communication Technologies, Electronics and Applied Mathematics, UCLouvain, Louvain-la-Neuve, Belgium
- Institute of Neuroscience, UCLouvain, Brussels, Belgium
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Younger E, Ellis EG, Parsons N, Pantano P, Tommasin S, Caeyenberghs K, Benito-León J, Romero JP, Joutsa J, Corp DT. Mapping Essential Tremor to a Common Brain Network Using Functional Connectivity Analysis. Neurology 2023; 101:e1483-e1494. [PMID: 37596042 PMCID: PMC10585696 DOI: 10.1212/wnl.0000000000207701] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 06/09/2023] [Indexed: 08/20/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The cerebello-thalamo-cortical circuit plays a critical role in essential tremor (ET). However, abnormalities have been reported in multiple brain regions outside this circuit, leading to inconsistent characterization of ET pathophysiology. Here, we test whether these mixed findings in ET localize to a common functional network and whether this network has therapeutic relevance. METHODS We conducted a systematic literature search to identify studies reporting structural or metabolic brain abnormalities in ET. We then used 'coordinate network mapping,' which leverages a normative connectome (n = 1,000) of resting-state fMRI data to identify regions commonly connected to findings across all studies. To assess whether these regions may be relevant for the treatment of ET, we compared our network with a therapeutic network derived from lesions that relieved ET. Finally, we investigated whether the functional connectivity of this ET symptom network is abnormal in an independent cohort of patients with ET as compared with healthy controls. RESULTS Structural and metabolic brain abnormalities in ET were located in heterogeneous regions throughout the brain. However, these coordinates were connected to a common functional brain network, including the cerebellum, thalamus, motor cortex, precuneus, inferior parietal lobe, and insula. The cerebellum was identified as the hub of this network because it was the only brain region that was both functionally connected to the findings of over 90% of studies and significantly different in connectivity compared with a control data set of other movement disorders. This network was strikingly similar to the therapeutic network derived from lesions improving ET, with key regions aligning in the thalamus and cerebellum. Furthermore, positive functional connectivity between the cerebellar network hub and the sensorimotor cortices was significantly reduced in patients with ET compared with healthy controls, and connectivity within this network was correlated with tremor severity and cognitive functioning. DISCUSSION These findings suggest that the cerebellum is the central hub of a network commonly connected to structural and metabolic abnormalities in ET. This network may have therapeutic utility in refining and informing new targets for neuromodulation of ET.
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Affiliation(s)
- Ellen Younger
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
| | - Elizabeth G Ellis
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Nicholas Parsons
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Patrizia Pantano
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Silvia Tommasin
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Karen Caeyenberghs
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Julián Benito-León
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Juan Pablo Romero
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Juho Joutsa
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Daniel T Corp
- From the Cognitive Neuroscience Unit (E.Y., E.G.E., N.P., K.C., D.T.C.), School of Psychology, Deakin University, Geelong, Australia; Human Neuroscience (P.P., S.T.), Sapienza University of Rome; IRCCS NEUROMED (P.P.), Pozzilli, Italy; Department of Neurology (J.B.-L.) and Research Institute (i+12), University Hospital "12 de Octubre"; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED) (J.B.-L.); Department of Medicine (J.B.-L.), Complutense University; Facultad de Ciencias Experimentales (J.P.R.), Universidad Francisco de Vitoria; Brain Damage Unit (J.P.R.), Hospital Beata María Ana, Madrid, Spain; Turku Brain and Mind Center (J.J.), Clinical Neurosciences, University of Turku; Turku PET Centre (J.J.), Neurocenter, Turku University Hospital, Finland; and Center for Brain Circuit Therapeutics (D.T.C.), Department of Neurology, Psychiatry, and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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10
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Kulkarni M, Kent JS, Park K, Guell X, Anteraper S. Resting-state functional connectivity-based parcellation of the human dentate nucleus: new findings and clinical relevance. Brain Struct Funct 2023; 228:1799-1810. [PMID: 37439862 DOI: 10.1007/s00429-023-02665-4] [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: 01/31/2023] [Accepted: 06/11/2023] [Indexed: 07/14/2023]
Abstract
For years, the cerebellum was left out of functional magnetic resonance imaging (fMRI) studies due to technological limitations. The advent of novel data acquisition and reconstruction strategies (e.g., whole-brain simultaneous multi-slice imaging) employing multi-channel array coils has overcome such limitations, ushering unprecedented improvements in temporal signal-to-noise ratio and spatiotemporal resolution. Here, we aim to provide a brief report on the deep cerebellar nuclei, specifically focusing on the dentate nuclei, the primary output nuclei, situated within both cognitive and motor cerebello-cerebral circuits. We highlight the importance of functional parcellation in refining our understanding of broad resting-state functional connectivity (RSFC) in both health and disease. First, we review work relevant to the functional topography of the dentate nuclei, including recent advances in functional parcellation. Next, we review RSFC studies using the dentate nuclei as seed regions of interest in neurological and psychiatric populations and discuss the potential benefits of applying functionally defined subdivisions. Finally, we discuss recent technological advances and underscore ultrahigh-field neuroimaging as a tool to potentiate functionally parcellated RSFC analyses in clinical populations.
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Affiliation(s)
- Maitreyee Kulkarni
- Department of Psychology, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Jerillyn S Kent
- Department of Psychology, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Katie Park
- University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - Xavier Guell
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sheeba Anteraper
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 2201 Inwood Road, Dallas, TX, USA.
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, United States.
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11
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Destrebecq V, Naeije G. Cognitive impairment in essential tremor assessed by the cerebellar cognitive affective syndrome scale. Front Neurol 2023; 14:1224478. [PMID: 37662041 PMCID: PMC10473101 DOI: 10.3389/fneur.2023.1224478] [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: 05/17/2023] [Accepted: 07/17/2023] [Indexed: 09/05/2023] Open
Abstract
Background Essential tremor (ET) is a movement disorder characterized by cerebellar neurodegenerative changes. ET is also associated with non-motor symptoms including cognitive impairment. The neuropsychologic profile of a patient with ET could relate to cerebellar cognitive affective syndrome (CCAS). Objective This study aimed to assess the prevalence of cognitive impairment in patients with ET and identify whether the cognitive impairment in ET corresponds to a CCAS. Methods Cognitive functions were evaluated with the CCAS-Scale (CCAS-S) in 20 patients with ET and 20 controls matched for age, sex, and level of education. The results of the CCAS-S were compared between patients and controls. The underlying determinant of CCAS inpatients with ET was identified through the correlation between the results of the CCAS-S and age at onset of symptoms, disease duration, and the Essential Tremor Rating Assessment Scale (TETRAS). Results On a group level, ET patients performed significantly worse than matched controls. In total, 13 individuals with ET had a definite CCAS (CCAS-S failed items ≥ 3). ASO and TETRAS scores significantly correlated with CCAS-S performances in ET patients. Conclusion CCAS is highly prevalent in patients with ET which supports the cerebellar pathophysiology of associated cognitive impairment and supports a more systematic use of the CCAS-S to cognitively assessed patients with ET.
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Affiliation(s)
- Virginie Destrebecq
- Clinique Universitaire de Bruxelles (CUB) Hôpital Erasme, Department of Neurology, Université Libre de Bruxelles, Brussels, Belgium
- Laboratoire de Neuroanatomie et Neuroimagerie translationnelles, UNI-ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Gilles Naeije
- Clinique Universitaire de Bruxelles (CUB) Hôpital Erasme, Department of Neurology, Université Libre de Bruxelles, Brussels, Belgium
- Laboratoire de Neuroanatomie et Neuroimagerie translationnelles, UNI-ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
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12
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Xiao P, Tao L, Zhang X, Li Q, Gui H, Xu B, Zhang X, He W, Chen H, Wang H, Lv F, Luo T, Cheng O, Luo J, Man Y, Xiao Z, Fang W. Using histogram analysis of the intrinsic brain activity mapping to identify essential tremor. Front Neurol 2023; 14:1165603. [PMID: 37404943 PMCID: PMC10317178 DOI: 10.3389/fneur.2023.1165603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/23/2023] [Indexed: 07/06/2023] Open
Abstract
Background Essential tremor (ET) is one of the most common movement disorders. Histogram analysis based on brain intrinsic activity imaging is a promising way to identify ET patients from healthy controls (HCs) and further explore the spontaneous brain activity change mechanisms and build the potential diagnostic biomarker in ET patients. Methods The histogram features based on the Resting-state functional magnetic resonance imaging (Rs-fMRI) data were extracted from 133 ET patients and 135 well-matched HCs as the input features. Then, a two-sample t-test, the mutual information, and the least absolute shrinkage and selection operator methods were applied to reduce the feature dimensionality. Support vector machine (SVM), logistic regression (LR), random forest (RF), and k-nearest neighbor (KNN) were used to differentiate ET and HCs, and classification performance of the established models was evaluated by the mean area under the curve (AUC). Moreover, correlation analysis was carried out between the selected histogram features and clinical tremor characteristics. Results Each classifier achieved a good classification performance in training and testing sets. The mean accuracy and area under the curve (AUC) of SVM, LR, RF, and KNN in the testing set were 92.62%, 0.948; 92.01%, 0.942; 93.88%, 0.941; and 92.27%, 0.939, respectively. The most power-discriminative features were mainly located in the cerebello-thalamo-motor and non-motor cortical pathways. Correlation analysis showed that there were two histogram features negatively and one positively correlated with tremor severity. Conclusion Our findings demonstrated that the histogram analysis of the amplitude of low-frequency fluctuation (ALFF) images with multiple machine learning algorithms could identify ET patients from HCs and help to understand the spontaneous brain activity pathogenesis mechanisms in ET patients.
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Affiliation(s)
- Pan Xiao
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Li Tao
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaoyu Zhang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qin Li
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Honge Gui
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Bintao Xu
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xueyan Zhang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wanlin He
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Huiyue Chen
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hansheng Wang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Fajin Lv
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Tianyou Luo
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Oumei Cheng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jin Luo
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yun Man
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zheng Xiao
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Weidong Fang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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13
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Yang Y, Zheng C, Chen B, Hernandez NC, Faust PL, Cai Z, Louis ED, Matuskey D. Decreased Synaptic Vesicle Glycoprotein 2A Binding in the Human Postmortem Essential Tremor Cerebellum: Evidence of Reduction in Synaptic Density. RESEARCH SQUARE 2023:rs.3.rs-2838184. [PMID: 37205584 PMCID: PMC10187382 DOI: 10.21203/rs.3.rs-2838184/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Objective Despite being one of the most prevalent neurological diseases, the pathophysiology of essential tremor (ET) is not fully understood. Neuropathological studies have identified numerous degenerative changes in the cerebellum of ET patients, however. These data align with considerable clinical and neurophysiological data linking ET to the cerebellum. While neuroimaging studies have variably shown mild atrophy in the cerebellum, marked atrophy is not a clear feature of the cerebellum in ET and that a search for a more suitable neuroimaging signature of neurodegeneration is in order. Postmortem studies in ET have examined different neuropathological alterations in the cerebellum, but as of yet have not focused on measures of generalized synaptic markers. This pilot study focuses on synaptic vesicle glycoprotein 2A (SV2A), a protein expressed in practically all synapses in the brain, as a measure of synaptic density in postmortem ET cases. Methods The current study utilized autoradiography with the SV2A radioligand [ 18 F]SDM-16 to assess synaptic density in the cerebellar cortex and dentate nucleus in three ET cases and three age-matched controls. Results Using [ 18 F]SDM-16, SV2A was 53% and 46% lower in the cerebellar cortex and dentate nucleus, respectively, in ET cases compared to age-matched controls. Conclusion For the first time, using in vitro SV2A autoradiography, we have observed significantly lower synaptic density in the cerebellar cortex and dentate nucleus of ET cases. Future research could focus on in vivo imaging in ET to explore whether SV2A imaging could serve as a much-needed disease biomarker.
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Affiliation(s)
| | | | | | | | - Phyllis L Faust
- Columbia University Vagelos College of Physicians and Surgeons and the New York Presbyterian Hospital
| | | | - Elan D Louis
- University of Texas Southwestern School of Medicine
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14
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The Perturbational Map of Low Frequency Repetitive Transcranial Magnetic Stimulation of Primary Motor Cortex in Movement Disorders. BRAIN DISORDERS 2023. [DOI: 10.1016/j.dscb.2023.100071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
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15
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Saccà V, Novellino F, Salsone M, Abou Jaoude M, Quattrone A, Chiriaco C, Madrigal JLM, Quattrone A. Challenging functional connectivity data: machine learning application on essential tremor recognition. Neurol Sci 2023; 44:199-207. [PMID: 36123559 DOI: 10.1007/s10072-022-06400-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/16/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND AIMS This paper aimed to investigate the usefulness of applying machine learning on resting-state fMRI connectivity data to recognize the pattern of functional changes in essential tremor (ET), a disease characterized by slight brain abnormalities, often difficult to detect using univariate analysis. METHODS We trained a support vector machine with a radial kernel on the mean signals extracted by 14 brain networks obtained from resting-state fMRI scans of 18 ET and 19 healthy control (CTRL) subjects. Classification performance between pathological and control subjects was evaluated using a tenfold cross-validation. Recursive feature elimination was performed to rank the importance of the extracted features. Moreover, univariate analysis using Mann-Whitney U test was also performed. RESULTS The machine learning algorithm achieved an AUC of 0.75, with four networks (language, primary visual, cerebellum, and attention), which have an essential role in ET pathophysiology, being selected as the most important features for classification. By contrast, the univariate analysis was not able to find significant results among these two conditions. CONCLUSION The machine learning approach identifies the changes in functional connectivity of ET patients, representing a promising instrument to discriminate specific pathological conditions and find novel functional biomarkers in resting-state fMRI studies.
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Affiliation(s)
- Valeria Saccà
- Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy.,Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Fabiana Novellino
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid (UCM), Av. Complutense s/n, 28040, Madrid, Spain. .,Instituto de Investigación Neuroquímica (IUINQ-UCM), Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Investigación Sanitaria Hospital, 12 de Octubre (Imas12), Madrid, Spain. .,Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy.
| | - Maria Salsone
- Institute of Molecular Bioimaging and Physiology, National Research Council, Milan, Italy.,Sleep Disorders Center, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Andrea Quattrone
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy.,Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | | | - José L M Madrigal
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid (UCM), Av. Complutense s/n, 28040, Madrid, Spain.,Instituto de Investigación Neuroquímica (IUINQ-UCM), Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Investigación Sanitaria Hospital, 12 de Octubre (Imas12), Madrid, Spain
| | - Aldo Quattrone
- Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy. .,Neuroscience Research Center, Magna Graecia University, Catanzaro, Italy.
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16
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Marapin RS, van der Horn HJ, van der Stouwe AMM, Dalenberg JR, de Jong BM, Tijssen MAJ. Altered brain connectivity in hyperkinetic movement disorders: A review of resting-state fMRI. Neuroimage Clin 2023; 37:103302. [PMID: 36669351 PMCID: PMC9868884 DOI: 10.1016/j.nicl.2022.103302] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/25/2022]
Abstract
BACKGROUND Hyperkinetic movement disorders (HMD) manifest as abnormal and uncontrollable movements. Despite reported involvement of several neural circuits, exact connectivity profiles remain elusive. OBJECTIVES Providing a comprehensive literature review of resting-state brain connectivity alterations using resting-state fMRI (rs-fMRI). We additionally discuss alterations from the perspective of brain networks, as well as correlations between connectivity and clinical measures. METHODS A systematic review was performed according to PRISMA guidelines and searching PubMed until October 2022. Rs-fMRI studies addressing ataxia, chorea, dystonia, myoclonus, tics, tremor, and functional movement disorders (FMD) were included. The standardized mean difference was used to summarize findings per region in the Automated Anatomical Labeling atlas for each phenotype. Furthermore, the activation likelihood estimation meta-analytic method was used to analyze convergence of significant between-group differences per phenotype. Finally, we conducted hierarchical cluster analysis to provide additional insights into commonalities and differences across HMD phenotypes. RESULTS Most articles concerned tremor (51), followed by dystonia (46), tics (19), chorea (12), myoclonus (11), FMD (11), and ataxia (8). Altered resting-state connectivity was found in several brain regions: in ataxia mainly cerebellar areas; for chorea, the caudate nucleus; for dystonia, sensorimotor and basal ganglia regions; for myoclonus, the thalamus and cingulate cortex; in tics, the basal ganglia, cerebellum, insula, and frontal cortex; for tremor, the cerebello-thalamo-cortical circuit; finally, in FMD, frontal, parietal, and cerebellar regions. Both decreased and increased connectivity were found for all HMD. Significant spatial convergence was found for dystonia, FMD, myoclonus, and tremor. Correlations between clinical measures and resting-state connectivity were frequently described. CONCLUSION Key brain regions contributing to functional connectivity changes across HMD often overlap. Possible increases and decreases of functional connections of a specific region emphasize that HMD should be viewed as a network disorder. Despite the complex interplay of physiological and methodological factors, this review serves to gain insight in brain connectivity profiles across HMD phenotypes.
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Affiliation(s)
- Ramesh S Marapin
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), Groningen, the Netherlands
| | - Harm J van der Horn
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands
| | - A M Madelein van der Stouwe
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), Groningen, the Netherlands
| | - Jelle R Dalenberg
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), Groningen, the Netherlands
| | - Bauke M de Jong
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands
| | - Marina A J Tijssen
- University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), Groningen, the Netherlands.
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17
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Bédard P, Panyakaew P, Cho HJ, Hallett M, Horovitz SG. Multimodal imaging of essential tremor and dystonic tremor. Neuroimage Clin 2022; 36:103247. [PMID: 36451353 PMCID: PMC9668651 DOI: 10.1016/j.nicl.2022.103247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 10/21/2022] [Accepted: 10/23/2022] [Indexed: 11/06/2022]
Abstract
Despite recent advances in tremor and dystonia classification, it remains difficult to discriminate essential tremor from dystonic tremor as they are similar in appearance and no biomarker exists. Further, tremor can appear in the same or a different body part than the dystonia. The aim of the current study was to better understand the differential pathophysiology of these tremors. We designed a cross-sectional case-control study and recruited 16 patients with essential tremor, 16 patients with dystonic tremor, and 17 age-matched healthy volunteers. We used multi-modal imaging combining resting-state functional MRI, diffusion tensor imaging, and magnetic resonance spectroscopy. We measured functional connectivity of resting-state fMRI to assess connectivity in the tremor network, fractional anisotropy and mean diffusivity with diffusion tensor imaging, and GABA+, Glutamate/Glutamine, Choline, and N-Acetylaspartate with spectroscopy (adjusted to Creatine). Our results showed reduced functional connectivity of resting-state fMRI between the cerebellum and dentate nucleus bilaterally for the essential tremor group, but not the dystonic tremor group, compared to healthy volunteers. There was higher fractional anisotropy in the middle cerebellar peduncle bilaterally for the dystonic tremor group compared to the essential tremor group as well as for essential tremor group compared to healthy volunteers. There was also higher fractional anisotropy in the red nucleus and corticospinal tract for essential tremor and dystonic tremor groups compared to healthy volunteers. We also showed reduced mean diffusivity in the cerebellum of both essential tremor and dystonic tremor groups compared to healthy volunteers. Finally, we found elevated GABA+/Cr in the cerebellum of the essential tremor and dystonic tremor groups compared to healthy volunteers, but no difference emerged between essential tremor and dystonic tremor groups. We did not find group differences in the other metabolites. Our results indicate cerebellar alterations in essential tremor and dystonic tremor patients compared to healthy volunteers, and further changes in the cerebellum network for the dystonic tremor patients. suggesting that the cerebellum is affected differently in both tremors.
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Affiliation(s)
- Patrick Bédard
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA
| | - Pattamon Panyakaew
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA,Chulalongkorn Center of Excellence for Parkinson’s Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok 10330, Thailand
| | - Hyun-Joo Cho
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA
| | - Silvina G. Horovitz
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA,Corresponding author.
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18
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Essential tremor and cognitive impairment: who, how, and why. Neurol Sci 2022; 43:4133-4143. [DOI: 10.1007/s10072-022-06037-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/23/2022] [Indexed: 10/18/2022]
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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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20
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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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21
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Mark VW. Functional neurological disorder: Extending the diagnosis to other disorders, and proposing an alternate disease term—Attentionally-modifiable disorder. NeuroRehabilitation 2022; 50:179-207. [DOI: 10.3233/nre-228003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: The term “functional neurological disorder,” or “FND,” applies to disorders whose occurrence of neurological symptoms fluctuate with the patient’s attention to them. However, many other disorders that are not called “FND” nonetheless can also follow this pattern. Consequently, guidelines are unclear for diagnosing “FND.” OBJECTIVE: To review the neurological conditions that follow this pattern, but which have not so far been termed “FND,” to understand their overlap with conditions that have been termed “FND,” and to discuss the rationale for why FND has not been diagnosed for them. METHOD: A systematic review of the PubMed literature registry using the terms “fluctuation,” “inconsistency,” or “attention” did not yield much in the way of these candidate disorders. Consequently, this review instead relied on the author’s personal library of peer-reviewed studies of disorders that have resembled FND but which were not termed this way, due to his longstanding interest in this problem. Consequently, this approach was not systematic and was subjective regarding disease inclusion. RESULTS: This review identified numerous, diverse conditions that generally involve fluctuating neurological symptoms that can vary with the person’s attention to them, but which have not been called “FND.” The literature was unclear for reasons for not referring to “FND” in these instances. CONCLUSION: Most likely because of historical biases, the use of the term “FND” has been unnecessarily restricted. Because at its core FND is an attentionally-influenced disorder that can respond well to behavioral treatments, the field of neurological rehabilitation could benefit by extending the range of conditions that could be considered as “FND” and referred for similar behavioral treatments. Because the term “FND” has been viewed unfavorably by some patients and clinical practitioners and whose treatment is not implied, the alternative term attentionally-modifiable disorder is proposed.
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Affiliation(s)
- Victor W. Mark
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
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22
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Erro R, Fasano A, Barone P, Bhatia KP. Milestones in Tremor Research: ten years later. Mov Disord Clin Pract 2022; 9:429-435. [PMID: 35582314 PMCID: PMC9092753 DOI: 10.1002/mdc3.13418] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Roberto Erro
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” Neuroscience section, University of Salerno Baronissi Italy
| | - 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
| | - Paolo Barone
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” Neuroscience section, University of Salerno Baronissi Italy
| | - Kailash P. Bhatia
- Department of Clinical and Movement Neurosciences UCL Queen Square Institute of Neurology, National Hospital for Neurology and Neurosurgery London United Kingdom
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23
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Pan MK, Kuo SH. Essential tremor: Clinical perspectives and pathophysiology. J Neurol Sci 2022; 435:120198. [PMID: 35299120 PMCID: PMC10363990 DOI: 10.1016/j.jns.2022.120198] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
Essential tremor (ET) is one of the most common neurological disorders and can be highly disabling. In recent years, studies on the clinical perspectives and pathophysiology have advanced our understanding of ET. Specifically, clinical heterogeneity of ET, with co-existence of tremor and other neurological features such as dystonia, ataxia, and cognitive dysfunction, has been identified. The cerebellum has been found to be the key brain region for tremor generation, and structural alterations of the cerebellum have been extensively studied in ET. Finally, four main ET pathophysiologies have been proposed: 1) environmental exposures to β-carboline alkaloids and the consequent olivocerebellar hyper-excitation, 2) cerebellar GABA deficiency, 3) climbing fiber synaptic pathology with related cerebellar oscillatory activity, 4) extra-cerebellar oscillatory activity. While these four theories are not mutually exclusive, they can represent distinctive ET subtypes, indicating multiple types of abnormal brain circuitry can lead to action tremor. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.
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24
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Gironell A. Is essential tremor a disorder of primary GABA dysfunction? Yes. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:259-284. [PMID: 35750365 PMCID: PMC9446196 DOI: 10.1016/bs.irn.2022.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Dysfunction in gamma-aminobutyric acid (GABA) neurotransmission has emerged as a prime suspect for the underlying neurochemical dysfunction in essential tremor (ET). This dysfunction has been termed the GABA hypothesis. We review findings to date supporting the 4 steps in this hypothesis in studies of cerebrospinal fluid, pathology, genetics, animal models, imaging, computational models, and human drugs, while not overlooking the evidence of negative studies and controversies. It remains to be elucidated whether reduced GABAergic tone is a primary contributing factor to ET pathophysiology, a consequence of altered Purkinje cell function, or even a result of Purkinje cell death. More studies are clearly needed to confirm both the neurodegenerative nature of ET and the reduction in GABA activity in the cerebellum. Also necessary is to test further therapies to enhance GABA transmission specifically focused on the cerebellar area.
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Affiliation(s)
- Alexandre Gironell
- Movement Disorders Unit, Department of Neurology, Sant Pau Hospital, Autonomous University of Barcelona, Catalonia, Spain.
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van den Berg KRE, Helmich RC. The Role of the Cerebellum in Tremor - Evidence from Neuroimaging. Tremor Other Hyperkinet Mov (N Y) 2021; 11:49. [PMID: 34820148 PMCID: PMC8603856 DOI: 10.5334/tohm.660] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/28/2021] [Indexed: 01/04/2023] Open
Abstract
Background Neuroimaging research has played a key role in identifying which cerebral changes are associated with tremor. Here we will focus on the cerebellum, which may drive tremor oscillations, process tremor-related afferents, modulate activity in remote brain regions, or a combination. Methods On the 6th of October 2021, we conducted a PubMed search to select articles providing neuroimaging evidence for cerebellar involvement in essential tremor (ET), Parkinson's disease (PD) tremor, and dystonic tremor (DT). Results In ET, tremor-related activity is found in motor areas of the bilateral cerebellum, and altered functional connectivity within and outside the cerebellum correlates with tremor severity. Furthermore, ET is associated with cerebellar atrophy, but also with compensatory structural changes outside the cerebellum (e.g. supplementary motor area). In PD, tremor-related cerebellar activity and increased cerebello-thalamic coupling has been found. Emerging evidence suggests that the cerebellum plays a key role in dopamine-resistant rest tremor and in postural tremor. Cerebellar structural alterations have been identified in PD, but only some relate to tremor. DT is associated with more widespread cerebral networks than other tremor types. Discussion In ET, the cerebellum likely acts as an oscillator, potentially due to loss of inhibitory mechanisms. In contrast, in PD the cerebellum may be a modulator, which contributes to tremor oscillations by influencing the thalamo-cortical system. The precise role of the cerebellum in DT remains unclear. We recommend that future research measures tremor-related activity directly by combining electrophysiology with neuroimaging, while brain stimulation techniques may be used to establish causality. Highlights This review of neuroimaging studies has provided convincing evidence that the cerebellum plays a key role in the pathophysiology of ET, PD tremor, and dystonic tremor syndromes. This contribution may consist of driving tremor oscillations, processing tremor-related afferents, modulating activity in remote brain regions, or all the above.
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Affiliation(s)
- Kevin R. E. van den Berg
- Centre of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Rick C. Helmich
- Centre of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
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26
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Pietracupa S, Bologna M, Tommasin S, Berardelli A, Pantano P. The Contribution of Neuroimaging to the Understanding of Essential Tremor Pathophysiology: a Systematic Review. THE CEREBELLUM 2021; 21:1029-1051. [PMID: 34657271 DOI: 10.1007/s12311-021-01335-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/10/2021] [Indexed: 12/14/2022]
Abstract
Essential tremor (ET) is one of the most common movement disorders. Over the last 10 years, magnetic resonance imaging (MRI) has shed light on the structural and functional abnormalities possibly involved in ET pathophysiology. In this systematic review, we aimed to identify the cortical and subcortical structures involved and the role that different brain areas play in the pathophysiology of motor and non-motor ET features. We found that structural (grey and white matter) cerebellar damage and connectivity alterations between the cerebellum and various cortical areas play a role in both motor and non-motor symptoms of ET. In particular, many studies found an association between MRI findings and non-motor symptoms.
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Affiliation(s)
| | - Matteo Bologna
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Silvia Tommasin
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Alfredo Berardelli
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Patrizia Pantano
- IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, Italy.,Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
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27
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Tikoo S, Suppa A, Tommasin S, Giannì C, Conte G, Mirabella G, Cardona F, Pantano P. The Cerebellum in Drug-naive Children with Tourette Syndrome and Obsessive–Compulsive Disorder. THE CEREBELLUM 2021; 21:867-878. [PMID: 34595609 PMCID: PMC9596574 DOI: 10.1007/s12311-021-01327-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/19/2021] [Indexed: 11/24/2022]
Abstract
Tourette syndrome (TS) and obsessive–compulsive disorder (OCD) are two neurodevelopmental disorders characterized by repetitive behaviors. Our recent study in drug-naive children with TS and OCD provided evidence of cerebellar involvement in both disorders. In addition, cerebellar functional connectivity (FC) was similar in TS patients without comorbidities (TSpure) and TS patients with OCD comorbidity (TS + OCD), but differed in pure OCD patients. To investigate in detail the cerebellar involvement in the pathophysiology of TS and OCD, we explored cerebellar structural and functional abnormalities in drug-naive children with TSpure, TS + OCD, and OCD and assessed possible correlations with severity scores. We examined 53 drug-naive children, classified as TSpure (n = 16), TS + OCD (n = 14), OCD (n = 11), or controls (n = 12). All subjects underwent a multimodal 3T magnetic resonance imaging examination. Cerebellar lobular volumes and quantitative diffusion tensor imaging parameters of cerebellar peduncles were used as measures of structural integrity. The dentate nucleus was selected as a region of interest to examine cerebello-cerebral functional connectivity alterations. Structural analysis revealed that both TSpure and TS + OCD patients had higher fractional anisotropy in cerebellar peduncles than controls. Conversely, OCD patients were characterized by lower fractional anisotropy than both controls and TSpure and TS + OCD patients. Lastly, cerebellar functional connectivity analysis revealed significant alterations in the cerebello-thalamo-cortical circuit in TSpure, TS + OCD, and OCD patients. Early cerebellar structural and functional changes in drug-naive pediatric TSpure, TS + OCD, and OCD patients support a primary role of the cerebellum in the pathophysiology of these disorders.
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Affiliation(s)
- Sankalp Tikoo
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Antonio Suppa
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Silvia Tommasin
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
- Department of Neuroimmunology, IRCCS Fondazione Santa Lucia, Rome, Italy
| | | | - Giulia Conte
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Giovanni Mirabella
- Department of Clinical and Experimental Sciences Section, Brescia University, Brescia, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Francesco Cardona
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Patrizia Pantano
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy.
- IRCCS Neuromed, Pozzilli, IS, Italy.
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Kakei S, Manto M, Tanaka H, Mitoma H. Pathophysiology of Cerebellar Tremor: The Forward Model-Related Tremor and the Inferior Olive Oscillation-Related Tremor. Front Neurol 2021; 12:694653. [PMID: 34262527 PMCID: PMC8273235 DOI: 10.3389/fneur.2021.694653] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/18/2021] [Indexed: 01/14/2023] Open
Abstract
Lesions in the Guillain-Mollaret (G-M) triangle frequently cause various types of tremors or tremor-like movements. Nevertheless, we know relatively little about their generation mechanisms. The deep cerebellar nuclei (DCN), which is a primary node of the triangle, has two main output paths: the primary excitatory path to the thalamus, the red nucleus (RN), and other brain stem nuclei, and the secondary inhibitory path to the inferior olive (IO). The inhibitory path contributes to the dentato-olivo-cerebellar loop (the short loop), while the excitatory path contributes to the cerebrocerebellar loop (the long loop). We propose a novel hypothesis: each loop contributes to physiologically distinct type of tremors or tremor-like movements. One type of irregular tremor-like movement is caused by a lesion in the cerebrocerebellar loop, which includes the primary path. A lesion in this loop affects the cerebellar forward model and deteriorates its accuracy of prediction and compensation of the feedback delay, resulting in irregular instability of voluntary motor control, i.e., cerebellar ataxia (CA). Therefore, this type of tremor, such as kinetic tremor, is usually associated with other symptoms of CA such as dysmetria. We call this type of tremor forward model-related tremor. The second type of regular tremor appears to be correlated with synchronized oscillation of IO neurons due, at least in animal models, to reduced degrees of freedom in IO activities. The regular burst activity of IO neurons is precisely transmitted along the cerebellocerebral path to the motor cortex before inducing rhythmical reciprocal activities of agonists and antagonists, i.e., tremor. We call this type of tremor IO-oscillation-related tremor. Although this type of regular tremor does not necessarily accompany ataxia, the aberrant IO activities (i.e., aberrant CS activities) may induce secondary maladaptation of cerebellar forward models through aberrant patterns of long-term depression (LTD) and/or long-term potentiation (LTP) of the cerebellar circuitry. Although our hypothesis does not cover all tremors or tremor-like movement disorders, our approach integrates the latest theories of cerebellar physiology and provides explanations how various lesions in or around the G-M triangle results in tremors or tremor-like movements. We propose that tremor results from errors in predictions carried out by the cerebellar circuitry.
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Affiliation(s)
- Shinji Kakei
- Department of Anatomy and Physiology, Jissen Women's University, Tokyo, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium
- Service des Neurosciences, University of Mons, Mons, Belgium
| | - Hirokazu Tanaka
- Faculty of Information Technology, Tokyo City University, Tokyo, Japan
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
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Becktepe JS, Busse J, Jensen-Kondering U, Toedt I, Wolff S, Zeuner KE, Berg D, Granert O, Deuschl G. White Matter Hyperintensities Are Associated With Severity of Essential Tremor in the Elderly. Front Neurol 2021; 12:694286. [PMID: 34262526 PMCID: PMC8273287 DOI: 10.3389/fneur.2021.694286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/20/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Essential tremor (ET) occurs with steeply increasing prevalence in the elderly, and apart from disease duration, age is independently associated with an increase of tremor amplitude and a decrease of frequency. White matter hyperintensities (WMHs) are a common finding in the elderly, and their role in the pathophysiology of ET is unknown. The aims of this study were to examine whether ET patients differ in their total or region-specific WMH volumes from healthy controls and to determine the impact of WMH on tremor characteristics. Methods: A total of 47 elderly ET patients with a mean age of 72 years and 39 age-matched healthy controls underwent a thorough clinical assessment and 3T MRI. Total WMH volumes were derived from T2-weighted fluid-attenuated inversion recovery (FLAIR) MR images. Additionally, region of interest-based WMH volumes for the Johns Hopkins University (JHU) white matter tracts and labels were calculated, and WMHs were assessed semiquantitatively using the Fazekas scale. Results: Essential tremor patients and healthy controls did not differ in their total or tract-specific WMH volumes or Fazekas scores. However, WMH volume was significantly positively correlated with tremor severity on the TETRAS scale, and there was a significant negative correlation with the mean accelerometric tremor frequency. In a multiple linear regression model including disease duration, age, and age-adjusted total WMH volume, only the WMH volume significantly predicted tremor severity, while age and disease duration were not significant. Conclusion: We found evidence for a direct association between WMH volume and tremor severity. If confirmed by larger studies, our findings could explain the well-known relation between age and tremor severity.
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Affiliation(s)
- Jos S Becktepe
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Johannes Busse
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Ulf Jensen-Kondering
- Department of Neuroradiology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Inken Toedt
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Stephan Wolff
- Department of Neuroradiology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Kirsten E Zeuner
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Daniela Berg
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Oliver Granert
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
| | - Günther Deuschl
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany
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30
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Holtbernd F, Shah NJ. Imaging the Pathophysiology of Essential Tremor-A Systematic Review. Front Neurol 2021; 12:680254. [PMID: 34220687 PMCID: PMC8244929 DOI: 10.3389/fneur.2021.680254] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/04/2021] [Indexed: 11/28/2022] Open
Abstract
Background: The pathophysiology underlying essential tremor (ET) still is poorly understood. Recent research suggests a pivotal role of the cerebellum in tremor genesis, and an ongoing controversy remains as to whether ET constitutes a neurodegenerative disorder. In addition, mounting evidence indicates that alterations in the gamma-aminobutyric acid neurotransmitter system are involved in ET pathophysiology. Here, we systematically review structural, functional, and metabolic neuroimaging studies and discuss current concepts of ET pathophysiology from an imaging perspective. Methods: We conducted a PubMed and Scopus search from 1966 up to December 2020, entering essential tremor in combination with any of the following search terms and their corresponding abbreviations: positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and gamma-aminobutyric acid (GABA). Results: Altered functional connectivity in the cerebellum and cerebello-thalamico-cortical circuitry is a prevalent finding in functional imaging studies. Reports from structural imaging studies are less consistent, and there is no clear evidence for cerebellar neurodegeneration. However, diffusion tensor imaging robustly points toward microstructural cerebellar changes. Radiotracer imaging suggests that the dopaminergic axis is largely preserved in ET. Similarly, measurements of nigral iron content and neuromelanin are unremarkable in most studies; this is in contrast to Parkinson's disease (PD). PET and MRS studies provide limited evidence for cerebellar and thalamic GABAergic dysfunction. Conclusions: There is robust evidence indicating that the cerebellum plays a key role within a multiple oscillator tremor network which underlies tremor genesis. However, whether cerebellar dysfunction relies on a neurodegenerative process remains unclear. Dopaminergic and iron imaging do not suggest a substantial overlap of ET with PD pathophysiology. There is limited evidence for alterations of the GABAergic neurotransmitter system in ET. The clinical, demographical, and genetic heterogeneity of ET translates into neuroimaging and likely explains the various inconsistencies reported.
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Affiliation(s)
- Florian Holtbernd
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Juelich GmbH, Juelich, Germany
- JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Juelich GmbH, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
- Department of Neurology, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
| | - N. Jon Shah
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Juelich GmbH, Juelich, Germany
- JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Juelich GmbH, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
- Department of Neurology, Rheinisch-Westfaelische Technische Hochschule Aachen University, Aachen, Germany
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