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Wang G, Song Y, Su J, Fan Z, Xu L, Fang P, Liu C, Long H, Hu C, Zhou L, Huang S, Zhou P, Wang K, Pang N, Shen H, Li S, Hu D, Xiao B, Zeng LL, Long L. Altered cerebellar-motor loop in benign adult familial myoclonic epilepsy type 1: The structural basis of cortical tremor. Epilepsia 2022; 63:3192-3203. [PMID: 36196770 DOI: 10.1111/epi.17430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/01/2022] [Accepted: 10/03/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Cortical tremor/myoclonus is the hallmark feature of benign adult familial myoclonic epilepsy (BAFME), the mechanism of which remains elusive. A hypothesis is that a defective control in the preexisting cerebellar-motor loop drives cortical tremor. Meanwhile, the basal ganglia system might also participate in BAFME. This study aimed to discover the structural basis of cortical tremor/myoclonus in BAFME. METHODS Nineteen patients with BAFME type 1 (BAFME1) and 30 matched healthy controls underwent T1-weighted and diffusion tensor imaging scans. FreeSurfer and spatially unbiased infratentorial template (SUIT) toolboxes were utilized to assess the motor cortex and the cerebellum. Probabilistic tractography was generated for two fibers to test the hypothesis: the dentato-thalamo-(M1) (primary motor cortex) and globus pallidus internus (GPi)-thalamic projections. Average fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) of each tract were extracted. RESULTS Cerebellar atrophy and dentate nucleus alteration were observed in the patients. In addition, patients with BAFME1 exhibited reduced AD and FA in the left and right dentato-thalamo-M1 nondecussating fibers, respectively false discovery rate (FDR) correction q < .05. Cerebellar projections showed negative correlations with somatosensory-evoked potential P25-N33 amplitude and were independent of disease duration and medication. BAFME1 patients also had increased FA and decreased MD in the left GPi-thalamic projection. Higher FA and lower RD in the right GPi-thalamic projection were also observed (FDR q < .05). SIGNIFICANCE The present findings support the hypothesis that the cerebello-thalamo-M1 loop might be the structural basis of cortical tremor in BAFME1. The basal ganglia system also participates in BAFME1 and probably serves a regulatory role.
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Affiliation(s)
- Ge Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Yanmin Song
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Department of Emergency, Xiangya Hospital, Central South University, Changsha, China
| | - Jianpo Su
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China
| | - Zhipeng Fan
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China
| | - Lin Xu
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Peng Fang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China.,Department of Military Medical Psychology, Air Force Medical University, Xian, China
| | - Chaorong Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Hongyu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Chongyu Hu
- Department of Neurology, Hunan People's Hospital, Changsha, China
| | - Luo Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Sha Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Pinting Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Kangrun Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Nan Pang
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatric, Xiangya Hospital, Central South University, Changsha, China
| | - Hui Shen
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China
| | - Shuyu Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Dewen Hu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Ling-Li Zeng
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
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Latorre A, Rocchi L, Magrinelli F, Mulroy E, Berardelli A, Rothwell JC, Bhatia KP. Unravelling the enigma of cortical tremor and other forms of cortical myoclonus. Brain 2021; 143:2653-2663. [PMID: 32417917 DOI: 10.1093/brain/awaa129] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 02/11/2020] [Accepted: 02/27/2020] [Indexed: 12/21/2022] Open
Abstract
Cortical tremor is a fine rhythmic oscillation involving distal upper limbs, linked to increased sensorimotor cortex excitability, as seen in cortical myoclonus. Cortical tremor is the hallmark feature of autosomal dominant familial cortical myoclonic tremor and epilepsy (FCMTE), a syndrome not yet officially recognized and characterized by clinical and genetic heterogeneity. Non-coding repeat expansions in different genes have been recently recognized to play an essential role in its pathogenesis. Cortical tremor is considered a rhythmic variant of cortical myoclonus and is part of the 'spectrum of cortical myoclonus', i.e. a wide range of clinical motor phenomena, from reflex myoclonus to myoclonic epilepsy, caused by abnormal sensorimotor cortical discharges. The aim of this update is to provide a detailed analysis of the mechanisms defining cortical tremor, as seen in FCMTE. After reviewing the clinical and genetic features of FCMTE, we discuss the possible mechanisms generating the distinct elements of the cortical myoclonus spectrum, and how cortical tremor fits into it. We propose that the spectrum is due to the evolution from a spatially limited focus of excitability to recruitment of more complex mechanisms capable of sustaining repetitive activity, overcoming inhibitory mechanisms that restrict excitatory bursts, and engaging wide areas of cortex. Finally, we provide evidence for a possible common denominator of the elements of the spectrum, i.e. the cerebellum, and discuss its role in FCMTE, according to recent genetic findings.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, IS, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
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Tétreault P, Baliki MN, Baria AT, Bauer WR, Schnitzer TJ, Apkarian AV. Inferring distinct mechanisms in the absence of subjective differences: Placebo and centrally acting analgesic underlie unique brain adaptations. Hum Brain Mapp 2018; 39:2210-2223. [PMID: 29417694 DOI: 10.1002/hbm.23999] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/22/2018] [Accepted: 01/30/2018] [Indexed: 12/31/2022] Open
Abstract
Development and maintenance of chronic pain is associated with structural and functional brain reorganization. However, few studies have explored the impact of drug treatments on such changes. The extent to which long-term analgesia is related to brain adaptations and its effects on the reversibility of brain reorganization remain unclear. In a randomized placebo-controlled clinical trial, we contrasted pain relief (3-month treatment period), and anatomical (gray matter density [GMD], assessed by voxel-based morphometry) and functional connectivity (resting state fMRI nodal degree count [DC]) adaptations, in 39 knee osteoarthritis (OA) patients (22 females), randomized to duloxetine (DLX, 60 mg once daily) or placebo. Pain relief was equivalent between treatment types. However, distinct circuitry (GMD and DC) could explain pain relief in each group: up to 85% of variance for placebo analgesia and 49% of variance for DLX analgesia. No behavioral measures (collected at entry into the study) could independently explain observed analgesia. Identified circuitry were outside of nociceptive circuitry and minimally overlapped with OA-abnormal or placebo response predictive brain regions. Mediation analysis revealed that changes in GMD and DC can influence each other across remote brain regions to explain observed analgesia. Therefore, we can conclude that distinct brain mechanisms underlie DLX and placebo analgesia in OA. The results demonstrate that even in the absence of differences in subjective pain relief, pharmacological treatments can be differentiated from placebo based on objective brain biomarkers. This is a crucial step to untangling mechanisms and advancing personalized therapy approaches for chronic pain.
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Affiliation(s)
- Pascal Tétreault
- Department of Physiology, Feinberg School of Medicine, Chicago, Illinois, 60611
| | - Marwan N Baliki
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Chicago, Illinois, 60611.,Shirley Ryan AbilityLab, Chicago, Illinois, 60611
| | - Alexis T Baria
- Department of Physiology, Feinberg School of Medicine, Chicago, Illinois, 60611
| | - William R Bauer
- Department of Neuroscience, University of Toledo, Toledo, Ohio, 43614-2598
| | - Thomas J Schnitzer
- Department of Rheumatology, Feinberg School of Medicine, Chicago, Illinois, 60611
| | - A Vania Apkarian
- Department of Physiology, Feinberg School of Medicine, Chicago, Illinois, 60611.,Anesthesiology Northwestern University, Feinberg School of Medicine, Chicago, Illinois, 60611
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van den Ende T, Sharifi S, van der Salm SMA, van Rootselaar AF. Familial Cortical Myoclonic Tremor and Epilepsy, an Enigmatic Disorder: From Phenotypes to Pathophysiology and Genetics. A Systematic Review. Tremor Other Hyperkinet Mov (N Y) 2018; 8:503. [PMID: 29416935 PMCID: PMC5801339 DOI: 10.7916/d85155wj] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/02/2018] [Indexed: 02/06/2023] Open
Abstract
Background Autosomal dominant familial cortical myoclonic tremor and epilepsy (FCMTE) is characterized by distal tremulous myoclonus, generalized seizures, and signs of cortical reflex myoclonus. FCMTE has been described in over 100 pedigrees worldwide, under several different names and acronyms. Pathological changes have been located in the cerebellum. This systematic review discusses the clinical spectrum, treatment, pathophysiology, and genetic findings. Methods We carried out a PubMed search, using a combination of the following search terms: cortical tremor, myoclonus, epilepsy, benign course, adult onset, familial, and autosomal dominant; this resulted in a total of 77 studies (761 patients; 126 pedigrees) fulfilling the inclusion and exclusion criteria. Results Phenotypic differences across pedigrees exist, possibly related to underlying genetic differences. A "benign" phenotype has been described in several Japanese families and pedigrees linked to 8q (FCMTE1). French patients (5p linkage; FCMTE3) exhibit more severe progression, and in Japanese/Chinese pedigrees (with unknown linkage) anticipation has been suggested. Preferred treatment is with valproate (mind teratogenicity), levetiracetam, and/or clonazepam. Several genes have been identified, which differ in potential pathogenicity. Discussion Based on the core features (above), the syndrome can be considered a distinct clinical entity. Clinical features may also include proximal myoclonus and mild progression with aging. Valproate or levetiracetam, with or without clonazepam, reduces symptoms. FCMTE is a heterogeneous disorder, and likely to include a variety of different conditions with mutations of different genes. Distinct phenotypic traits might reflect different genetic mutations. Genes involved in Purkinje cell outgrowth or those encoding for ion channels or neurotransmitters seem good candidate genes.
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Affiliation(s)
- Tom van den Ende
- Department of Neurology and Clinical Neurophysiology, Amsterdam Neuroscience, Academic Medical Center, Amsterdam, The Netherlands
| | - Sarvi Sharifi
- Department of Neurology and Clinical Neurophysiology, Amsterdam Neuroscience, Academic Medical Center, Amsterdam, The Netherlands
| | - Sandra M. A. van der Salm
- Brain Center Rudolf Magnus, Department of Neurology and Neurosurgery, University Medical Center, Utrecht, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Zwolle, The Netherlands
| | - Anne-Fleur van Rootselaar
- Department of Neurology and Clinical Neurophysiology, Amsterdam Neuroscience, Academic Medical Center, Amsterdam, The Netherlands
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Long L, Zeng LL, Song Y, Shen H, Fang P, Zhang L, Xu L, Gong J, Zhang YC, Zhang Y, Zhou P, Huang S, Chen S, Xie Y, Hu D, Xiao B. Altered cerebellar-cerebral functional connectivity in benign adult familial myoclonic epilepsy. Epilepsia 2016; 57:941-8. [PMID: 27037791 DOI: 10.1111/epi.13372] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2016] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The pathogenesis of benign adult familial myoclonic epilepsy (BAFME) remains unknown, although cerebellar pathologic changes and brain hyperexcitability have been reported. We used resting-state functional magnetic resonance imaging (fMRI) to examine the functional connectivity between the cerebellum and cerebrum in a Chinese family with BAFME for the first time. METHODS Eleven adults with BAFME and 15 matched healthy controls underwent resting-state blood oxygen level-dependent (BOLD) fMRI scanning. The cerebellar seeds, including the bilateral crus I, lobule VIII, lobule VIIb, and lobule IV&V, were defined a priori. Next, regional time courses were obtained for each individual by averaging the BOLD time series over all voxels in each seed region. Then, seed-based functional connectivity z-maps were produced by computing Pearson's correlation coefficients (converted to z-scores by Fisher transformation) between each seed signal and the time series from all other voxels within the entire brain. Finally, a second-level random-effect two-sample t-test was performed on the individual z-maps in a voxel-wise manner. RESULTS Reduced functional connectivity of the right cerebellar crus I with the left middle frontal gyrus and right cerebellar lobule IX was observed in the default network of BAFME. Enhanced functional connectivity of the left cerebellar lobule VIII with the bilateral middle temporal gyri, right putamen, and left cerebellar crus I was found in the dorsal attention network of BAFME. Enhanced functional connectivity between the left cerebellar lobule VIIb and right frontal pole was found in the control network of BAFME. SIGNIFICANCE Altered cerebellar-cerebral functional connectivity may contribute to the understanding of the nosogenesis of BAFME and explain the cognitive dysfunction in this Chinese family with BAFME.
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Affiliation(s)
- Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ling-Li Zeng
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan, China
| | - Yanmin Song
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Emergency, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hui Shen
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan, China
| | - Peng Fang
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan, China
| | - Linlin Zhang
- Department of Neurology, Fuyang People's Hospital, Fuyang, Anhui, China
| | - Lin Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jian Gong
- Department of Neurology, Fuyang People's Hospital, Fuyang, Anhui, China
| | - Yun-Ci Zhang
- Department of Neurology, Fuyang People's Hospital, Fuyang, Anhui, China
| | - Yong Zhang
- Department of Neurology, Fuyang People's Hospital, Fuyang, Anhui, China
| | - Pinting Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Sha Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Si Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yuanyuan Xie
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Dewen Hu
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
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