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Sinokki A, Säisänen L, Hyppönen J, Silvennoinen K, Kälviäinen R, Mervaala E, Karjalainen PA, Rissanen SM. Detecting negative myoclonus during long-term home measurements using wearables. Clin Neurophysiol 2023; 156:166-174. [PMID: 37952446 DOI: 10.1016/j.clinph.2023.10.005] [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: 02/15/2023] [Revised: 08/22/2023] [Accepted: 10/17/2023] [Indexed: 11/14/2023]
Abstract
OBJECTIVE The aim of this study was to develop a feasible method for the detection of negative myoclonus (NM) through long-term home measurements in patients with progressive myoclonus epilepsy type 1. METHODS The number and duration of silent periods (SP) associated with NM were detected during a 48 h home recording using wearable surface electromyography (EMG) sensors. RESULTS A newly developed algorithm was able to find short (50-69 ms), intermediate (70-100 ms), and long (101- 500 ms) SPs from EMG data. Negative myoclonus assessed by the algorithm correlated significantly with the video-recorded and physician-evaluated unified myoclonus rating scale (UMRS) scores of NM and action myoclonus. Silent period duration, number, and their combination, correlated strongly and significantly also with the Singer score, which assesses functional status and ambulation. CONCLUSIONS Negative myoclonus can be determined objectively using long-term EMG measurements in home environment. With long-term measurements, we can acquire more reliable quantified information about NM as a symptom, compared to short evaluation at the clinic. SIGNIFICANCE As measured using SPs, NM may be a clinically useful measure for monitoring disease progression or assessing antimyoclonic drug effects objectively.
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Affiliation(s)
- Aku Sinokki
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland.
| | - Laura Säisänen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland; Kuopio Epilepsy Center, Department of Clinical Neurophysiology, Kuopio University Hospital, Full Member of ERN EpiCARE, Kuopio, Finland
| | - Jelena Hyppönen
- Kuopio Epilepsy Center, Department of Clinical Neurophysiology, Kuopio University Hospital, Full Member of ERN EpiCARE, Kuopio, Finland; Institute of Clinical Medicine, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Katri Silvennoinen
- Kuopio Epilepsy Center, Neurocenter, Kuopio University Hospital, Full Member of ERN EpiCARE, Kuopio, Finland; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Reetta Kälviäinen
- Institute of Clinical Medicine, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland; Kuopio Epilepsy Center, Neurocenter, Kuopio University Hospital, Full Member of ERN EpiCARE, Kuopio, Finland
| | - Esa Mervaala
- Kuopio Epilepsy Center, Department of Clinical Neurophysiology, Kuopio University Hospital, Full Member of ERN EpiCARE, Kuopio, Finland; Institute of Clinical Medicine, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Pasi A Karjalainen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - Saara M Rissanen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland; Adamant Health Ltd, Kuopio, Finland
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Balestrini S, Mei D, Sisodiya SM, Guerrini R. Steps to Improve Precision Medicine in Epilepsy. Mol Diagn Ther 2023; 27:661-672. [PMID: 37755653 PMCID: PMC10590329 DOI: 10.1007/s40291-023-00676-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2023] [Indexed: 09/28/2023]
Abstract
Precision medicine is an old concept, but it is not widely applied across human health conditions as yet. Numerous attempts have been made to apply precision medicine in epilepsy, this has been based on a better understanding of aetiological mechanisms and deconstructing disease into multiple biological subsets. The scope of precision medicine is to provide effective strategies for treating individual patients with specific agent(s) that are likely to work best based on the causal biological make-up. We provide an overview of the main applications of precision medicine in epilepsy, including the current limitations and pitfalls, and propose potential strategies for implementation and to achieve a higher rate of success in patient care. Such strategies include establishing a definition of precision medicine and its outcomes; learning from past experiences, from failures and from other fields (e.g. oncology); using appropriate precision medicine strategies (e.g. drug repurposing versus traditional drug discovery process); and using adequate methods to assess efficacy (e.g. randomised controlled trials versus alternative trial designs). Although the progress of diagnostic techniques now allows comprehensive characterisation of each individual epilepsy condition from a molecular, biological, structural and clinical perspective, there remain challenges in the integration of individual data in clinical practice to achieve effective applications of precision medicine in this domain.
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Affiliation(s)
- S Balestrini
- Neuroscience Department, Meyer Children's Hospital IRCSS, Florence, Italy
- University of Florence, Florence, Italy
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter, UK
| | - D Mei
- Neuroscience Department, Meyer Children's Hospital IRCSS, Florence, Italy
| | - S M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter, UK
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children's Hospital IRCSS, Florence, Italy.
- University of Florence, Florence, Italy.
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3
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Silvennoinen K, Säisänen L, Hyppönen J, Rissanen SM, Karjalainen PA, D'Ambrosio S, Jimenez‐Jimenez D, Zagaglia S, Rothwell JC, Balestrini S, Sisodiya SM, Julkunen P, Mervaala E, Kälviäinen R. Short- and long-interval intracortical inhibition in EPM1 is related to genotype. Epilepsia 2023; 64:208-217. [PMID: 36398398 PMCID: PMC10107775 DOI: 10.1111/epi.17466] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Progressive myoclonic epilepsy type 1 (EPM1) is caused by biallelic alterations in the CSTB gene, most commonly dodecamer repeat expansions. Although transcranial magnetic stimulation (TMS)-induced long-interval intracortical inhibition (LICI) was previously reported to be normal in EPM1, short-interval intracortical inhibition (SICI) was reduced. We explored the association between these measures and the clinical and genetic features in a separate group of patients with EPM1. METHODS TMS combined with electromyography was performed under neuronavigation. LICI was induced with an inter-stimulus interval (ISI) of 100 ms, and SICI with ISIs of 2 and 3 ms, and their means (mSICIs) were expressed as the ratio of conditioned to unconditioned stimuli. LICI and mSICI were compared between patients and controls. Nonparametric correlation was used to study the association between inhibition and parameters of clinical severity, including the Unified Myoclonus Rating Scale (UMRS); among patients with EPM1 due to biallelic expansion repeats, also the association with the number of repeats was assessed. RESULTS The study protocol was completed in 19 patients (15 with biallelic expansion repeats and 4 compound heterozygotes), and 7 healthy, age- and sex-matched control participants. Compared to controls, patients demonstrated significantly less SICI (median mSICI ratio 1.18 vs 0.38; p < .001). Neither LICI nor SICI was associated with parameters of clinical severity. In participants with biallelic repeat expansions, the number of repeats in the more affected allele (greater repeat number [GRN]) correlated with LICI (rho = 0.872; p < .001) and SICI (rho = 0.689; p = .006). SIGNIFICANCE Our results strengthen the finding of deranged γ-aminobutyric acid (GABA)ergic inhibition in EPM1. LICI and SICI may have use as markers of GABAergic impairment in future trials of disease-modifying treatment in this condition. Whether a higher number of expansion repeats leads to greater GABAergic impairment warrants further study.
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Affiliation(s)
- Katri Silvennoinen
- Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
| | - Laura Säisänen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Jelena Hyppönen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
| | - Saara M. Rissanen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | | | - Sasha D'Ambrosio
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Dipartimento di Scienze Biomediche e Cliniche "L. Sacco"Università degli Studi di MilanoMilanItaly
| | - Diego Jimenez‐Jimenez
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Sara Zagaglia
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - John C. Rothwell
- Sobell Department of Motor Neuroscience and Movement DisordersUCL Queen Square Institute of NeurologyLondonUK
| | - Simona Balestrini
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
- Neuroscience DepartmentMember of ERN EpiCARE, Meyer Children HospitalFlorenceItaly
| | - Sanjay M. Sisodiya
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
| | - Petro Julkunen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Esa Mervaala
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Institute of Clinical Medicine, School of Medicine, Faculty of Health SciencesUniversity of Eastern FinlandKuopioFinland
| | - Reetta Kälviäinen
- Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Institute of Clinical Medicine, School of Medicine, Faculty of Health SciencesUniversity of Eastern FinlandKuopioFinland
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Identifying novel biomarkers with TMS-EEG - Methodological possibilities and challenges. J Neurosci Methods 2022; 377:109631. [PMID: 35623474 DOI: 10.1016/j.jneumeth.2022.109631] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 05/09/2022] [Accepted: 05/21/2022] [Indexed: 12/17/2022]
Abstract
Biomarkers are essential for understanding the underlying pathologies in brain disorders and for developing effective treatments. Combined transcranial magnetic stimulation and electroencephalography (TMS-EEG) is an emerging neurophysiological tool that can be used for biomarker development. This method can identify biomarkers associated with the function and dynamics of the inhibitory and excitatory neurotransmitter systems and effective connectivity between brain areas. In this review, we outline the current state of the TMS-EEG biomarker field by summarizing the existing protocols and the possibilities and challenges associated with this methodology.
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Braden AA, Weatherspoon SE, Boardman T, Williard T, Adkins A, Gibbs SK, Wheless JW, Narayana S. Image-guided TMS is safe in a predominately pediatric clinical population. Clin Neurophysiol 2022; 137:193-206. [DOI: 10.1016/j.clinph.2022.01.133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
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Pang S, D'Ambrosio S, Battaglia G, Jiménez-Jiménez D, Perulli M, Silvennoinen K, Zagaglia S, Sisodiya SM, Balestrini S. The impact of Transcranial Magnetic Stimulation (TMS) on seizure course in people with and without epilepsy. Clin Neurophysiol Pract 2022; 7:174-182. [PMID: 35800886 PMCID: PMC9254260 DOI: 10.1016/j.cnp.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 04/21/2022] [Accepted: 05/17/2022] [Indexed: 11/20/2022] Open
Abstract
Previous evidence on risk of TMS-induced seizures is anecdotal. There was no evidence that TMS caused changes in epileptiform activity. No seizures were induced by TMS in healthy subjects.
Objective To elucidate the effects of single and paired-pulse TMS on seizure activity at electrographic and clinical levels in people with and without epilepsy. Methods A cohort of 35 people with epilepsy, two people with alternating hemiplegia of childhood (AHC) with no epilepsy, and 16 healthy individuals underwent single or paired-pulse TMS combined with EEG. Clinical records and subject interviews were used to examine seizure frequency four weeks before and after TMS. Results There were no significant differences in seizure frequency in any subject after TMS exposure. There was no occurrence of seizures in healthy individuals, and no worsening of hemiplegic attacks in people with AHC. Conclusions No significant changes in seizure activity were found before or after TMS. Significance This study adds evidence on the safety of TMS in people with and without epilepsy with follow-up of four weeks after TMS.
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Silvennoinen K, Balestrini S, Rothwell JC, Sisodiya SM. Transcranial magnetic stimulation as a tool to understand genetic conditions associated with epilepsy. Epilepsia 2020; 61:1818-1839. [PMID: 32783192 PMCID: PMC8432162 DOI: 10.1111/epi.16634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 12/30/2022]
Abstract
Advances in genetics may enable a deeper understanding of disease mechanisms and promote a shift to more personalised medicine in the epilepsies. At present, understanding of consequences of genetic variants mainly relies on preclinical functional work; tools for acquiring similar data from the living human brain are needed. Transcranial magnetic stimulation (TMS), in particular paired-pulse TMS protocols which depend on the function of cortical GABAergic interneuron networks, has the potential to become such a tool. For this report, we identified and reviewed 23 publications on TMS studies of cortical excitability and inhibition in 15 different genes or conditions relevant to epilepsy. Reduced short-interval intracortical inhibition (SICI) and reduced cortical silent period (CSP) duration were the most commonly reported findings, suggesting abnormal GABAA - (SICI) or GABAB ergic (CSP) signalling. For several conditions, these findings are plausible based on established evidence of involvement of the GABAergic system; for some others, they may inform future research around such mechanisms. Challenges of TMS include lack of complete understanding of the neural underpinnings of the measures used: hypotheses and analyses should be based on existing clinical and preclinical data. Further pitfalls include gathering sufficient numbers of participants, and the effect of confounding factors, especially medications. TMS-EEG is a unique perturbational technique to study the intrinsic properties of the cortex with excellent temporal resolution; while it has the potential to provide further information of use in interpreting effects of genetic variants, currently the links between measures and neurophysiology are less established. Despite these challenges, TMS is a tool with potential for elucidating the system-level in vivo functional consequences of genetic variants in people carrying genetic changes of interest, providing unique insights.
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Affiliation(s)
- Katri Silvennoinen
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Department of UCL Queen Square, Institute of Neurology, London, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
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