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Vegezzi E, Ishiura H, Bragg DC, Pellerin D, Magrinelli F, Currò R, Facchini S, Tucci A, Hardy J, Sharma N, Danzi MC, Zuchner S, Brais B, Reilly MM, Tsuji S, Houlden H, Cortese A. Neurological disorders caused by novel non-coding repeat expansions: clinical features and differential diagnosis. Lancet Neurol 2024; 23:725-739. [PMID: 38876750 DOI: 10.1016/s1474-4422(24)00167-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 06/16/2024]
Abstract
Nucleotide repeat expansions in the human genome are a well-known cause of neurological disease. In the past decade, advances in DNA sequencing technologies have led to a better understanding of the role of non-coding DNA, that is, the DNA that is not transcribed into proteins. These techniques have also enabled the identification of pathogenic non-coding repeat expansions that cause neurological disorders. Mounting evidence shows that adult patients with familial or sporadic presentations of epilepsy, cognitive dysfunction, myopathy, neuropathy, ataxia, or movement disorders can be carriers of non-coding repeat expansions. The description of the clinical, epidemiological, and molecular features of these recently identified non-coding repeat expansion disorders should guide clinicians in the diagnosis and management of these patients, and help in the genetic counselling for patients and their families.
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Affiliation(s)
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - D Cristopher Bragg
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Pellerin
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Riccardo Currò
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Stefano Facchini
- IRCCS Mondino Foundation, Pavia, Italy; Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Arianna Tucci
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; William Harvey Research Institute, Queen Mary University of London, London, UK
| | - John Hardy
- Department of Neurogedengerative Disease, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Matt C Danzi
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Stephan Zuchner
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada
| | - Mary M Reilly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Institute of Medical Genomics, International University of Health and Welfare, Chiba, Japan
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Andrea Cortese
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
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Latorre A, Rocchi L, Paparella G, Manzo N, Bhatia KP, Rothwell JC. Changes in cerebellar output abnormally modulate cortical myoclonus sensorimotor hyperexcitability. Brain 2024; 147:1412-1422. [PMID: 37956080 PMCID: PMC10994547 DOI: 10.1093/brain/awad384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 10/07/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023] Open
Abstract
Cortical myoclonus is produced by abnormal neuronal discharges within the sensorimotor cortex, as demonstrated by electrophysiology. Our hypothesis is that the loss of cerebellar inhibitory control over the motor cortex, via cerebello-thalamo-cortical connections, could induce the increased sensorimotor cortical excitability that eventually causes cortical myoclonus. To explore this hypothesis, in the present study we applied anodal transcranial direct current stimulation over the cerebellum of patients affected by cortical myoclonus and healthy controls and assessed its effect on sensorimotor cortex excitability. We expected that anodal cerebellar transcranial direct current stimulation would increase the inhibitory cerebellar drive to the motor cortex and therefore reduce the sensorimotor cortex hyperexcitability observed in cortical myoclonus. Ten patients affected by cortical myoclonus of various aetiology and 10 aged-matched healthy control subjects were included in the study. All participants underwent somatosensory evoked potentials, long-latency reflexes and short-interval intracortical inhibition recording at baseline and immediately after 20 min session of cerebellar anodal transcranial direct current stimulation. In patients, myoclonus was recorded by the means of surface EMG before and after the cerebellar stimulation. Anodal cerebellar transcranial direct current stimulation did not change the above variables in healthy controls, while it significantly increased the amplitude of somatosensory evoked potential cortical components, long-latency reflexes and decreased short-interval intracortical inhibition in patients; alongside, a trend towards worsening of the myoclonus after the cerebellar stimulation was observed. Interestingly, when dividing patients in those with and without giant somatosensory evoked potentials, the increment of the somatosensory evoked potential cortical components was observed mainly in those with giant potentials. Our data showed that anodal cerebellar transcranial direct current stimulation facilitates-and does not inhibit-sensorimotor cortex excitability in cortical myoclonus syndromes. This paradoxical response might be due to an abnormal homeostatic plasticity within the sensorimotor cortex, driven by dysfunctional cerebello-thalamo-cortical input to the motor cortex. We suggest that the cerebellum is implicated in the pathophysiology of cortical myoclonus and that these results could open the way to new forms of treatment or treatment targets.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari 09042, Italy
| | - Giulia Paparella
- Department of Neurology, IRCCS Neuromed, Pozzilli, IS 86077, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Nicoletta Manzo
- Department of Neurology, IRCCS San Camillo Hospital, Venice 30126, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
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Cherian A, Divya KP, Krishnan ARS. Familial adult myoclonus epilepsy: a pragmatic approach. Acta Neurol Belg 2024; 124:389-394. [PMID: 38114875 DOI: 10.1007/s13760-023-02432-6] [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: 06/29/2023] [Accepted: 11/10/2023] [Indexed: 12/21/2023]
Abstract
Familial Adult Myoclonus Epilepsy (FAME), with a prevalence of < 1/35 000, is known under different acronyms. The disease is transmitted in an autosomal dominant manner and is characterized by the occurrence of cortical myoclonic tremor, overt myoclonus, and rare bilateral tonic-clonic seizures. FAME is considered neurodegenerative, although it is relatively slow in progression. Diagnosis is based on specific neurophysiological testing, namely jerk-locked back-averaging, somatosensory evoked potentials, long latency reflex, and motor evoked potentials, among others. Imaging data, including functional magnetic resonance imaging, indicate a cortical origin of the cortical myoclonic tremor and decreased cerebellar activation. Cerebellar changes in Purkinje cells have been noted, from few neuropathology reports, in patients from isolated pedigrees. The differential diagnosis includes essential tremor, some forms of genetic generalized epilepsy, and progressive myoclonus epilepsies. Treatment is mainly symptomatic.
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Affiliation(s)
- Ajith Cherian
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Medical College P.O, Trivandrum, PIN-695011, Kerala, India
| | - K P Divya
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Medical College P.O, Trivandrum, PIN-695011, Kerala, India.
| | - A R Swathy Krishnan
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Medical College P.O, Trivandrum, PIN-695011, Kerala, India
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Cruciani A, Pellegrino G, Todisco A, Motolese F, Sferruzzi M, Norata D, Santoro F, Musumeci G, Rossi M, Pilato F, Di Lazzaro V, Capone F. High-frequency transcranial alternating current stimulation matching individual frequency of somatosensory evoked high-frequency oscillations can modulate the somatosensory system through thalamocortical pathway. Cereb Cortex 2024; 34:bhad481. [PMID: 38100323 DOI: 10.1093/cercor/bhad481] [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: 10/02/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
tACS (transcranial alternating current stimulation) is a technique for modulating brain activity through electrical current. Its effects depend on cortical entrainment, which is most effective when transcranial alternating current stimulation matches the brain's natural rhythm. High-frequency oscillations produced by external stimuli are useful for studying the somatosensory pathway. Our study aims to explore transcranial alternating current stimulation's impact on the somatosensory system when synchronized with individual high-frequency oscillation frequencies. We conducted a randomized, sham-controlled study with 14 healthy participants. The study had three phases: Individualized transcranial alternating current stimulation (matching the individual's high-frequency oscillation rhythm), Standard transcranial alternating current stimulation (600 Hz), and sham stimulation. We measured early and late HFO components after median nerve electrical stimulation at three time points: before (T0), immediately after (T1), and 10 min after transcranial alternating current stimulation (T2). Compared to Sham and Standard stimulation Individualized transcranial alternating current stimulation significantly enhanced high-frequency oscillations, especially the early component, immediately after stimulation and for at least 15 min. No other effects were observed for other high-frequency oscillation measures. In summary, our study provides initial evidence that transcranial alternating current stimulation synchronized with an individual's high-frequency oscillation frequency can precisely and time-specifically modulate thalamocortical activity. These insights may pave the way for innovative, personalized neuromodulation methods for the somatosensory system.
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Affiliation(s)
- Alessandro Cruciani
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Giovanni Pellegrino
- Epilepsy Program, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada
| | - Antonio Todisco
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Francesco Motolese
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Marco Sferruzzi
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Davide Norata
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
- Neurological Clinic, Department of Experimental and Clinical Medicine (DIMSC), Marche Polytechnic University, 60121 Ancona, Italy
| | - Francesca Santoro
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Gabriella Musumeci
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Mariagrazia Rossi
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Fabio Pilato
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Vincenzo Di Lazzaro
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
| | - Fioravante Capone
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma 21-00128, Italy
- Department of Medicine and Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo Roma 200-00128, Italy
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Latorre A, Belvisi D, Rothwell JC, Bhatia KP, Rocchi L. Rethinking the neurophysiological concept of cortical myoclonus. Clin Neurophysiol 2023; 156:125-139. [PMID: 37948946 DOI: 10.1016/j.clinph.2023.10.007] [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: 01/28/2023] [Revised: 09/04/2023] [Accepted: 10/13/2023] [Indexed: 11/12/2023]
Abstract
Cortical myoclonus is thought to result from abnormal electrical discharges arising in the sensorimotor cortex. Given the ease of recording of cortical discharges, electrophysiological features of cortical myoclonus have been better characterized than those of subcortical forms, and electrophysiological criteria for cortical myoclonus have been proposed. These include the presence of giant somatosensory evoked potentials, enhanced long-latency reflexes, electroencephalographic discharges time-locked to individual myoclonic jerks and significant cortico-muscular connectivity. Other features that are assumed to support the cortical origin of myoclonus are short-duration electromyographic bursts, the presence of both positive and negative myoclonus and cranial-caudal progression of the jerks. While these criteria are widely used in clinical practice and research settings, their application can be difficult in practice and, as a result, they are fulfilled only by a minority of patients. In this review we reappraise the evidence that led to the definition of the electrophysiological criteria of cortical myoclonus, highlighting possible methodological incongruencies and misconceptions. We believe that, at present, the diagnostic accuracy of cortical myoclonus can be increased only by combining observations from multiple tests, according to their pathophysiological rationale; nevertheless, larger studies are needed to standardise the methods, to resolve methodological issues, to establish the diagnostic criteria sensitivity and specificity and to develop further methods that might be useful to clarify the pathophysiology of myoclonus.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom.
| | - Daniele Belvisi
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Franceschetti S, Visani E, Panzica F, Coppola A, Striano P, Canafoglia L. Cortico-muscular coherence and brain networks in familial adult myoclonic epilepsy and progressive myoclonic epilepsy. Clin Neurophysiol 2023; 151:74-82. [PMID: 37216715 DOI: 10.1016/j.clinph.2023.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/12/2023] [Accepted: 04/24/2023] [Indexed: 05/24/2023]
Abstract
OBJECTIVE Familial Adult Myoclonic Epilepsy (FAME) presents with action-activated myoclonus, often associated with epilepsy, sharing various features with Progressive Myoclonic Epilepsy (PMEs), but with slower course and limited motor disability. We aimed our study to identify measures suitable to explain the different severity of FAME2 compared to EPM1, the most common PME, and to detect the signature of the distinctive brain networks. METHODS We analyzed the EEG-EMG coherence (CMC) during segmental motor activity and indexes of connectivity in the two patient groups, and in healthy subjects (HS). We also investigated the regional and global properties of the network. RESULTS In FAME2, differently from EPM1, we found a well-localized distribution of beta-CMC and increased betweenness-centrality (BC) on the sensorimotor region contralateral to the activated hand. In both patient groups, compared to HS, there was a decline in the network connectivity indexes in the beta and gamma band, which was more obvious in FAME2. CONCLUSIONS In FAME2, better localized CMC and increased BC in comparison with EPM1 patients could counteract the severity and the spreading of the myoclonus. Decreased indexes of cortical integration were more severe in FAME2. SIGNIFICANCE Our measures correlated with different motor disabilities and identified distinctive brain network impairments.
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Affiliation(s)
- Silvana Franceschetti
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
| | - Elisa Visani
- Bioengineering Unit, Dept. of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
| | - Ferruccio Panzica
- Clinical Engineering, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
| | - Antonietta Coppola
- Department of Neuroscience, Odontostomatology and Reproductive Sciences, Federico II, University of Naples, Napoli, Italy
| | - Pasquale Striano
- IRCCS Istituto "Giannina Gaslini", Genova, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Laura Canafoglia
- Integrated Diagnostics for Epilepsy, Dept of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
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Cuccurullo C, Striano P, Coppola A. Familial Adult Myoclonus Epilepsy: A Non-Coding Repeat Expansion Disorder of Cerebellar-Thalamic-Cortical Loop. Cells 2023; 12:1617. [PMID: 37371086 DOI: 10.3390/cells12121617] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Familial adult myoclonus Epilepsy (FAME) is a non-coding repeat expansion disorder that has been reported under different acronyms and initially linked to four main loci: FAME1 (8q23.3-q24.1), FAME 2 (2p11.1-q12.1), FAME3 (5p15.31-p15.1), and FAME4 (3q26.32-3q28). To date, it is known that the genetic mechanism underlying FAME consists of the expansion of similar non-coding pentanucleotide repeats, TTTCA and TTTTA, in different genes. FAME is characterized by cortical tremor and myoclonus usually manifesting within the second decade of life, and infrequent seizures by the third or fourth decade. Cortical tremor is the core feature of FAME and is considered part of a spectrum of cortical myoclonus. Neurophysiological investigations as jerk-locked back averaging (JLBA) and corticomuscular coherence analysis, giant somatosensory evoked potentials (SEPs), and the presence of long-latency reflex I (or C reflex) at rest support cortical tremor as the result of the sensorimotor cortex hyperexcitability. Furthermore, the application of transcranial magnetic stimulation (TMS) protocols in FAME patients has recently shown that inhibitory circuits are also altered within the primary somatosensory cortex and the concomitant involvement of subcortical networks. Moreover, neuroimaging studies and postmortem autoptic studies indicate cerebellar alterations and abnormal functional connectivity between the cerebellum and cerebrum in FAME. Accordingly, the pathophysiological mechanism underlying FAME has been hypothesized to reside in decreased sensorimotor cortical inhibition through dysfunction of the cerebellar-thalamic-cortical loop, secondary to primary cerebellar pathology. In this context, the non-coding pentameric expansions have been proposed to cause cerebellar damage through an RNA-mediated toxicity mechanism. The elucidation of the underlying pathological mechanisms of FAME paves the way to novel therapeutic possibilities, such as RNA-targeting treatments, possibly applicable to other neurodegenerative non-coding disorders.
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Affiliation(s)
- Claudia Cuccurullo
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Federico II University of Naples, 80131 Naples, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, 16126 Genova, Italy
| | - Antonietta Coppola
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Federico II University of Naples, 80131 Naples, Italy
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Dubbioso R, Suppa A, Tijssen MAJ, Ikeda A. Familial adult myoclonus epilepsy: Neurophysiological investigations. Epilepsia 2023. [PMID: 36806000 DOI: 10.1111/epi.17553] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/20/2023]
Abstract
Familial adult myoclonus epilepsy (FAME) also described as benign adult familial myoclonus epilepsy (BAFME) is a high-penetrant autosomal dominant condition featuring cortical myoclonus of varying frequency and occasional/rare convulsive seizures. In this update we provide a detailed overview of the main neurophysiological findings so far reported in patients with FAME/BAFME. After reviewing the diagnostic contribution of each neurophysiological technique, we discuss the possible mechanisms underlying cortical hyperexcitability and suggest the involvement of more complex circuits engaging cortical and subcortical structures, such as the cerebellum. We, thus, propose that FAME/BAFME clinical features should arise from an "abnormal neuronal network activity," where the cerebellum represents a possible common denominator. In the last part of the article, we suggest that future neurophysiological studies using more advanced transcranial magnetic stimulation (TMS) protocols could be used to evaluate the functional connectivity between the cerebellum and cortical structures. Finally, non-invasive brain stimulation techniques such as repetitive TMS or transcranial direct current stimulation could be assessed as potential therapeutic tools to ameliorate cortical excitability.
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Affiliation(s)
- Raffaele Dubbioso
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Federico II University of Naples, Napoli, Italy
| | - Antonio Suppa
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - Marina A J Tijssen
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands.,Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology Kyoto University Graduate School of Medicine Shogoin, Kyoto, Japan
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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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10
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Cruciani A, Lanzone J, Musumeci G, Di Lazzaro V, Marano M. Focal vibrations enhance somatosensory facilitation in healthy subjects: A pilot study on Equistasi ® and high-frequency oscillations. Front Neurol 2022; 13:1052989. [PMID: 36504649 PMCID: PMC9727278 DOI: 10.3389/fneur.2022.1052989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 11/03/2022] [Indexed: 11/24/2022] Open
Abstract
Background Equistasi® is a vibrotactile device composed of nanotechnology fibers that converts temperature change into mechanical energy by self-producing a focal vibration. It is used in non-pharmacological rehabilitation in patients with movement disorders and multiple sclerosis sequelae. Nonetheless, the mechanism underlying such an improvement in motor functions is still poorly understood. Objectives We designed a small uncontrolled pilot trial to explore the effect of Equistasi® on the somatosensory pathway through the analysis of high-frequency oscillations (HFOs). Methods For all the included subjects, we recorded somatosensory-evoked potentials (SEPs) at the baseline (T0) and at 60 min after the application of Equistasi® (T1) on the seventh cervical vertebra level and at the forearm over each flexor carpi radialis, bilaterally. Then, we extracted the HFOs from the N20 signal and compared the HFO duration and area under the curve pre- and post-Equistasi® application. Results In a head-to-head comparison of T0 to T1 data, there was a statistically significant reduction in the total HFO area (p < 0.01), which was prominent for the late component (p = 0.025). No statistical differences have been found between T0 and T1 HFO duration (p > 0.05). We further evaluated the N20 amplitude from the onset to the N20 peak to avoid possible interpretational bias. No statistical differences have been found between T0 and T1 (p = 0.437). Conclusion Our clinical hypothesis, supported by preliminary data, is that vibrotactile afference delivered by the device could work by interfering with the somatosensory processing, rather than by peripheral effects.
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Affiliation(s)
- Alessandro Cruciani
- Research Unit of Neurology, Neurophysiology and Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy,Operative Research Unit of Neurology, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Jacopo Lanzone
- Istituti Clinici Scientifici Maugeri IRCCS, Neurorehabilitation Unit of Milan Institute, Milan, Italy
| | - Gabriella Musumeci
- Research Unit of Neurology, Neurophysiology and Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy,Operative Research Unit of Neurology, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Vincenzo Di Lazzaro
- Research Unit of Neurology, Neurophysiology and Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy,Operative Research Unit of Neurology, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Massimo Marano
- Research Unit of Neurology, Neurophysiology and Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy,Operative Research Unit of Neurology, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy,*Correspondence: Massimo Marano
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11
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Le Cong D, Sato D, Ikarashi K, Fujimoto T, Ochi G, Yamashiro K. Effect of whole-hand water flow stimulation on the neural balance between excitation and inhibition in the primary somatosensory cortex. Front Hum Neurosci 2022; 16:962936. [DOI: 10.3389/fnhum.2022.962936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Sustained peripheral somatosensory stimulations, such as high-frequency repetitive somatosensory stimulation (HF-RSS) and vibrated stimulation, are effective in altering the balance between excitation and inhibition in the somatosensory cortex (S1) and motor cortex (M1). A recent study reported that whole-hand water flow (WF) stimulation induced neural disinhibition in the M1. Based on previous results, we hypothesized that whole-hand WF stimulation would lead to neural disinhibition in the S1 because there is a strong neural connection between M1 and S1 and aimed to examine whether whole-hand WF stimulation would change the neural balance between excitation and inhibition in the S1. Nineteen healthy volunteers were studied by measuring excitation and inhibition in the S1 before and after each of the four 15-min interventions. The excitation and inhibition in the S1 were assessed using somatosensory evoked potentials (SEPs) and paired-pulse inhibition (PPI) induced by single- and paired-pulse stimulations, respectively. The four interventions were as follows: control, whole-hand water immersion, whole-hand WF, and HF-RSS. The results showed no significant changes in SEPs and PPI following any intervention. However, changes in PPI with an interstimulus interval (ISI) of 30 ms were significantly correlated with the baseline value before whole-hand WF. Thus, the present findings indicated that the whole-hand WF stimulation had a greater decreased neural inhibition in participants with higher neural inhibition in the S1 at baseline. Considering previous results on M1, the present results possibly show that S1 has lower plasticity than M1 and that the duration (15 min) of each intervention may not have been enough to alter the balance of excitation and inhibition in the S1.
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12
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Tomasevic L, Siebner HR, Thielscher A, Manganelli F, Pontillo G, Dubbioso R. Relationship between high-frequency activity in the cortical sensory and the motor hand areas, and their myelin content. Brain Stimul 2022; 15:717-726. [PMID: 35525389 DOI: 10.1016/j.brs.2022.04.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The human primary sensory (S1) and primary motor (M1) hand areas feature high-frequency neuronal responses. Electrical nerve stimulation evokes high-frequency oscillations (HFO) at around 650 Hz in the contralateral S1. Likewise, transcranial magnetic stimulation (TMS) of M1 can evoke a series of descending volleys in the corticospinal pathway that can be detected non-invasively with a paired-pulse TMS protocol, called short interval intracortical facilitation (SICF). SICF features several peaks of facilitation of motor evoked potentials in contralateral hand muscles, which are separated by inter-peak intervals resembling HFO rhythmicity. HYPOTHESIS In this study, we tested the hypothesis that the individual expressions of HFO and SICF are tightly related to each other and to the regional myelin content in the sensorimotor cortex. METHODS In 24 healthy volunteers, we recorded HFO and SICF, and, in a subgroup of 20 participants, we mapped the cortical myelin content using the ratio between the T1- and T2-weighted MRI signal as read-out. RESULTS The individual frequencies and magnitudes of HFO and SICF curves were tightly correlated: the intervals between the first and second peak of cortical HFO and SICF showed a positive linear relationship (r = 0.703, p < 0.001), while their amplitudes were inversely related (r = -0.613, p = 0.001). The rhythmicity, but not the magnitude of the high-frequency responses, was related to the cortical myelin content: the higher the cortical myelin content, the shorter the inter-peak intervals of HFO and SICF. CONCLUSION The results confirm a tight functional relationship between high-frequency responses in S1 (i.e., HFO) and M1 (i.e., as measured with SICF). They also establish a link between the degree of regional cortical myelination and the expression of high-frequency responses in the human sensorimotor cortex, giving further the opportunity to infer their generators.
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Affiliation(s)
- Leo Tomasevic
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University, Hospital Amager and Hvidovre, Copenhagen, Denmark.
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University, Hospital Amager and Hvidovre, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Fredriksberg, Copenhagen, Denmark; Institute for Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University, Hospital Amager and Hvidovre, Copenhagen, Denmark; Department of Health Technology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Italy
| | - Giuseppe Pontillo
- Department of Advanced Biomedical Sciences, University "Federico II", Naples, Italy
| | - Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Italy.
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13
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Dubbioso R, Bove M, Boccia D, D'Ambrosio V, Nolano M, Manganelli F, Iodice R. Neurophysiological and behavioural correlates of ocrelizumab therapy on manual dexterity in patients with primary progressive multiple sclerosis. J Neurol 2022; 269:4791-4801. [PMID: 35419681 PMCID: PMC9363320 DOI: 10.1007/s00415-022-11114-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/20/2022]
Abstract
Background Hand dexterity impairment is a key feature of disability in people with primary progressive multiple sclerosis (PPMS). So far, ocrelizumab, a recombinant humanized monoclonal antibody that selectively depletes CD20-expressing B cells, is the only therapy approved for PPMS and recent analysis reported its ability to reduce the risk of upper limb disability progression. However, the neural mechanisms underlying hand impairment in PPMS and the brain networks behind the effect of ocrelizumab on manual dexterity are not fully understood. Objective Main aims of our study were: (i) to investigate neurophysiological and behavioural correlates of hand function impairment in subjects with PPMS, and (ii) to use neurophysiologic and behavioural measures to track the effects of ocrelizumab therapy on manual dexterity. Methods Seventeen PPMS patients and 17 healthy-controls underwent routine neurophysiological protocols assessing the integrity of cortico-spinal and somatosensory pathways and advanced transcranial magnetic stimulation (TMS) protocols evaluating inhibitory (short and long interval intracortical inhibition, short-latency afferent inhibition) and facilitatory (motor thresholds, intracortical facilitation, short-interval intracortical facilitation) circuits in the primary motor cortex. All subjects also underwent behavioural analysis of hand dexterity by means of nine-hole peg test and finger movement analysis, and hand strength with handgrip and three-point pinch test. Neurophysiological and clinical assessments of hand functionality were also performed after 1 year of ocrelizumab therapy. Results At baseline PPMS patients displayed a significant impairment of hand dexterity and strength compared to healthy controls (all p < 0.03). Neurophysiological study disclosed prolonged latencies of standard somatosensory and motor evoked potentials (all p < 0.025) and an overall reduction of intracortical excitability at TMS protocols, involving both excitatory and inhibitory circuits. Importantly, hand dexterity impairment, indexed by delayed 9HPT, correlated with TMS protocols investigating cortical sensorimotor integration (short-latency afferent inhibition, SAI), p = 0.009. Both parameters, 9HPT (p = 0.01) and SAI (p = 0.01), displayed a significant improvement after 1 year of therapy with ocrelizumab. Conclusion Intracortical sensorimotor networks are involved in hand dexterity dysfunction of PPMS. Ocrelizumab therapy displays a beneficial effect on hand dexterity impairment most likely through intracortical networks implicated in fast sensorimotor integration.
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Affiliation(s)
- Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Via Sergio Pansini, 5. 80131, Napoli, Italy.
| | - Marco Bove
- IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi Di Genova, 16132, Genoa, Italy
| | - Daniele Boccia
- IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Neuroscience Genetics, Maternal and Child Health (DINOGMI)Center of Excellence for Biomedical Research (CEBR), University of Genoa, RehabilitationGenoa, Ophthalmology, Italy
| | - Vincenzo D'Ambrosio
- Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy
| | - Maria Nolano
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Via Sergio Pansini, 5. 80131, Napoli, Italy.,Department of Neurology, Istituti Clinici Scientifici Maugeri IRCCS, 27100, Pavia, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Via Sergio Pansini, 5. 80131, Napoli, Italy
| | - Rosa Iodice
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Via Sergio Pansini, 5. 80131, Napoli, Italy
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