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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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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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Guo Y, Xiao Y, Chen LF, Yin DH, Wang RD. Lance Adams syndrome: two cases report and literature review. J Int Med Res 2022; 50:3000605211059933. [PMID: 35220777 PMCID: PMC8894979 DOI: 10.1177/03000605211059933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypoxic myoclonus, also known as Lance Adams syndrome, is a rare syndrome that results from the serious brain damage caused by cerebral hypoxia that often follows cardiopulmonary resuscitation. This current case report describes two patients with post-hypoxic myoclonus, both of whom received cardiopulmonary resuscitation. The neurological symptoms of these two patients were significantly improved by the administration of clonazepam and sodium valproate sustained-release tablets. The report presents a literature review detailing the pathogenesis, diagnosis and treatment of Lance Adams syndrome. The timely diagnosis and treatment of Lance Adams syndrome can significantly improve the quality of life of patients. Valproic acid, clonazepam and other antiepileptic drugs can be used. Whether levetiracetam is effective for cortical myoclonus requires further clinical study.
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Affiliation(s)
- Yu Guo
- Department of Neurology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Yan Xiao
- Department of Neurology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Li-Fa Chen
- Department of Neurology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - De-Hui Yin
- Department of Neurology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Ruo-Dan Wang
- Department of Neurology, Second Affiliated Hospital of Army Medical University, Chongqing, China
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Eberhardt O, Topka H. Myoclonic Disorders. Brain Sci 2017; 7:E103. [PMID: 28805718 PMCID: PMC5575623 DOI: 10.3390/brainsci7080103] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/06/2017] [Accepted: 08/08/2017] [Indexed: 01/17/2023] Open
Abstract
Few movement disorders seem to make a straightforward approach to diagnosis and treatment more difficult and frustrating than myoclonus, due to its plethora of causes and its variable classifications. Nevertheless, in recent years, exciting advances have been made in the elucidation of the pathophysiology and genetic basis of many disorders presenting with myoclonus. Here, we provide a review of all of the important types of myoclonus encountered in pediatric and adult neurology, with an emphasis on the recent developments that have led to a deeper understanding of this intriguing phenomenon. An up-to-date list of the genetic basis of all major myoclonic disorders is presented. Randomized studies are scarce in myoclonus therapy, but helpful pragmatic approaches at diagnosis as well as treatment have been recently suggested.
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Affiliation(s)
- Olaf Eberhardt
- Klinik für Neurologie, Klinikum Bogenhausen, Städt. Klinikum München GmbH, Englschalkinger Str. 77, 81925 München, Germany.
| | - Helge Topka
- Klinik für Neurologie, Klinikum Bogenhausen, Städt. Klinikum München GmbH, Englschalkinger Str. 77, 81925 München, Germany.
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