1
|
Suetterlin K, Mӓnnikkӧ R, Jayaseelan DL. Inherited myotonias. HANDBOOK OF CLINICAL NEUROLOGY 2024; 203:25-38. [PMID: 39174252 DOI: 10.1016/b978-0-323-90820-7.00008-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
The inherited myotonias are a complex group of diseases caused by variations in genes that encode or modulate the expression of ion channels that regulate muscle excitability. These variations alter muscle membrane excitability allowing mild depolarization, causing myotonic discharges. There are two groups of inherited myotonia, the dystrophic and the nondystrophic myotonias (NDM). Patients with NDM have a pure muscle phenotype with variations in channel genes expressed in muscle. The dystrophic myotonias are caused by genes that alter splicing leading to more systemic effects with myotonia being one of a number of systemic symptoms. This chapter therefore focuses on the key aspects of the NDMs. The NDMs manifest with varying clinical phenotypes, which change from infancy to adulthood. The pathogenicity of different variants can be determined using heterologous expression systems to understand the alteration in channel properties and predict the likelihood of causing disease. Myotonia itself can be managed by lifestyle modifications. A number of randomized controlled trials demonstrate efficacy of mexiletine and lamotrigine in treating myotonia, but there is an evidence that specific variants may be more or less well-treated by the different agents because of how they alter the channel kinetics. More work is needed to develop more targeted genetic treatments.
Collapse
Affiliation(s)
- Karen Suetterlin
- John Walton Centre for Muscular Dystrophy and AGE Research Group, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Roope Mӓnnikkӧ
- UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Dipa L Jayaseelan
- Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom.
| |
Collapse
|
2
|
Shen L. Effects of Pelvic Floor Muscle Massage on the Pregnancy Outcome of Frozen Embryo Transfer in Patients with Thin Endometrium. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:2803363. [PMID: 35813410 PMCID: PMC9259337 DOI: 10.1155/2022/2803363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 11/18/2022]
Abstract
Objective To observe the effects of pelvic floor muscle mass on the priority outcome of frozen embryo transfer in patients with thin endometrium. Methods The patients who were prepared for freeze-thaw embryo transfer were randomly divided into the study group and control group. Both groups of patients began to take estradiol valerate tablets 3 mg on the third day of menstrual cycle and added progesterone for luteal support after 14 days. Both groups selected high-quality embryos for embryo transfer on the day of embryo transfer. The basic information, embryo transfer, intimal thickness, intimal type, clinical pregnancy rate, and early abortion rate of the two groups were compared. Results The intimal thickness of patients in the control group and the study group on the second day of menstruation was (0.49 ± 0.03) and (0.45 ± 0.02) and that before progesterone was (1.17 ± 0.03) and (1.20 ± 0.04), respectively (P < 0.05). At the same time, the number of excellent embryos in the study group was significantly higher than that in the control group (P < 0.05), but there was no significant difference in the number of transplants between the two groups (P > 0.05). The proportion of intimal blood flow of type III + II in the study group was significantly higher than that in the control group (P < 0.05). The main adverse pregnancy outcomes of the whole group included biochemical pregnancy, early abortion, and ectopic pregnancy. The incidence of biochemical pregnancy in the control group and the study group was 63.3% (38/60) and 40.0% (24/60), respectively. The incidence of biochemical pregnancy in the control group was significantly higher than that in the study group, but there was no significant difference in the incidence of early abortion and ectopic pregnancy between the two groups (P > 0.05). Conclusion Pelvic floor muscle massage can improve endometrial thickness and subendometrial blood flow, so as to improve the pregnancy rate of frozen thawed embryo transfer patients.
Collapse
Affiliation(s)
- Longying Shen
- Kuishan Health Center of Rizhao Economic and Technological Development Zone, China
| |
Collapse
|
3
|
Matthews E, Holmes S, Fialho D. Skeletal muscle channelopathies: a guide to diagnosis and management. Pract Neurol 2021; 21:196-204. [PMID: 33563766 DOI: 10.1136/practneurol-2020-002576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2020] [Indexed: 12/17/2022]
Abstract
Skeletal muscle channelopathies are a group of rare episodic genetic disorders comprising the periodic paralyses and the non-dystrophic myotonias. They may cause significant morbidity, limit vocational opportunities, be socially embarrassing, and sometimes are associated with sudden cardiac death. The diagnosis is often hampered by symptoms that patients may find difficult to describe, a normal examination in the absence of symptoms, and the need to interpret numerous tests that may be normal or abnormal. However, the symptoms respond very well to holistic management and pharmacological treatment, with great benefit to quality of life. Here, we review when to suspect a muscle channelopathy, how to investigate a possible case and the options for therapy once a diagnosis is made.
Collapse
Affiliation(s)
- Emma Matthews
- Atkinson-Morley Neuromuscular Centre, St George's University Hospitals NHS Foundation Trust, London, UK
- Department of Neuromuscular Diseases, UCL, Institute of Neurology, London, UK
| | - Sarah Holmes
- Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, UK
| | - Doreen Fialho
- Department of Neuromuscular Diseases, UCL, Institute of Neurology, London, UK
- Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, UK
- Department of Clinical Neurophysiology, King's College Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
4
|
Yu XJ, Ding Y. The roles of mitochondrial tRNA mutations in non-dystrophic myotonias. Mitochondrial DNA B Resour 2020; 5:3796-3801. [PMID: 33367105 PMCID: PMC7682739 DOI: 10.1080/23802359.2020.1839364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
According a recent report by Heidari et al., a mutational screening for candidate pathogenic mitochondrial tRNA (mt-tRNA) mutations were performed in 45 Iranian patients with non-dystrophic myotonia (NDM) and 70 control subjects. Through PCR amplification and direct sequence analysis, nine mt-tRNA mutations were identified: tRNAMet T4454C, tRNATrp A5568G, tRNACys T5794C, tRNAArg A10438T and T10462C, tRNALeu(CUN) A12308G, tRNAThr A15907G, A15924G and G15928A. However, through the database searches and phylogenetic conservation analysis, we noticed that the tRNAThr A15924G, G15928A and tRNALeu(CUN) A12308G mutations should be classified 'pathogenic'. Thus, the roles of mt-tRNA mutations in clinical expression of NDM needed to be further experimentally addressed.
Collapse
Affiliation(s)
- Xue-Jiao Yu
- Department of Clinical Laboratory, Quzhou People's Hospital, Quzhou, China
| | - Yu Ding
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
5
|
Stunnenberg BC, LoRusso S, Arnold WD, Barohn RJ, Cannon SC, Fontaine B, Griggs RC, Hanna MG, Matthews E, Meola G, Sansone VA, Trivedi JR, van Engelen BG, Vicart S, Statland JM. Guidelines on clinical presentation and management of nondystrophic myotonias. Muscle Nerve 2020; 62:430-444. [PMID: 32270509 PMCID: PMC8117169 DOI: 10.1002/mus.26887] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/01/2020] [Accepted: 04/04/2020] [Indexed: 12/26/2022]
Abstract
The nondystrophic myotonias are rare muscle hyperexcitability disorders caused by gain-of-function mutations in the SCN4A gene or loss-of-function mutations in the CLCN1 gene. Clinically, they are characterized by myotonia, defined as delayed muscle relaxation after voluntary contraction, which leads to symptoms of muscle stiffness, pain, fatigue, and weakness. Diagnosis is based on history and examination findings, the presence of electrical myotonia on electromyography, and genetic confirmation. In the absence of genetic confirmation, the diagnosis is supported by detailed electrophysiological testing, exclusion of other related disorders, and analysis of a variant of uncertain significance if present. Symptomatic treatment with a sodium channel blocker, such as mexiletine, is usually the first step in management, as well as educating patients about potential anesthetic complications.
Collapse
Affiliation(s)
- Bas C. Stunnenberg
- Department of Neurology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Samantha LoRusso
- Department of Neurology, Ohio State University Wexner Medical Center, Columbus, Ohio
| | - W. David Arnold
- Department of Neurology, Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Richard J. Barohn
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas
| | - Stephen C. Cannon
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Bertrand Fontaine
- Assistance Publique-Hôpitaix de Paris, Sorbonne Université, INSERM, Service of Neuro-Myology and UMR 974, Institute of Myology, University Hospital Pitié-Salpêtrière, Paris, France
| | - Robert C. Griggs
- Department of Neurology, University of Rochester, Rochester, New York
| | - Michael G. Hanna
- MRC Centre for Neuromuscular Diseases, Department of Neuromuscular diseases, UCL Queen Square Institute of Neurology, United Kingdom
| | - Emma Matthews
- MRC Centre for Neuromuscular Diseases, Department of Neuromuscular diseases, UCL Queen Square Institute of Neurology, United Kingdom
| | - Giovanni Meola
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Valeria A. Sansone
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
- Neurorehabilitation Unit, University of Milan, NEuroMuscular Omnicentre (NEMO), Fondazione Serena Onlus, Milan, Italy
| | - Jaya R. Trivedi
- Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, Texas
| | | | - Savine Vicart
- Assistance Publique-Hôpitaix de Paris, Sorbonne Université, INSERM, Service of Neuro-Myology and UMR 974, Institute of Myology, University Hospital Pitié-Salpêtrière, Paris, France
| | - Jeffrey M. Statland
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas
| |
Collapse
|
6
|
Abstract
PURPOSE OF REVIEW This article aims to review the current and upcoming treatment options of primary muscle channelopathies including the non-dystrophic myotonias and periodic paralyses. RECENT FINDINGS The efficacy of mexiletine in the treatment of myotonia is now supported by two randomised placebo-controlled trials, one of which utilised a novel aggregated n-of-1 design. This has resulted in licencing of the drug via orphan drug status. There is also good evidence that mexiletine is well tolerated and safe in this patient group without the need for intensive monitoring. A range of alternative antimyotonic treatment options include lamotrigine, carbamazepine and ranolazine exist with variable evidence base. In vitro studies have shown insight into reasons for treatment failure of some medications with certain genotypes opening the era of mutation-specific therapy such as use of flecainide. In the periodic paralyses, the ability of MRI to distinguish between reversible oedema and irreversible fatty replacement makes it an increasingly useful tool to guide and assess pharmacological treatment. Unfortunately, the striking efficacy of bumetanide in hypokalaemic periodic paralysis animal models was not replicated in a recent pilot study in humans. SUMMARY The treatment of skeletal muscle channelopathies combines dietary and lifestyle advice together with pharmacological interventions. The rarity of these conditions remains a barrier for clinical studies but the example of the aggregated n-of-1 trial of mexiletine shows that innovative trial design can overcome these hurdles. Further research is required to test efficacy of drugs shown to have promising characteristics in preclinical experiments such as safinamide, riluzule and magnesium for myotonia or bumetanide for hypokalaemic periodic paralysis.
Collapse
Affiliation(s)
- Nantaporn Jitpimolmard
- Queen Square Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
- Rehabilitation Medicine Department, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Emma Matthews
- Queen Square Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
- Atkinson-Morley Neuromuscular Centre, St George’s University Hospitals Foundation Trust, London, UK
| | - Doreen Fialho
- Queen Square Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
| |
Collapse
|
7
|
Heidari MM, Keshmirshekan A, Bidakhavidi M, Khosravi A, Bandari Z, Khatami M, Nafissi S. A novel heteroplasmic mutation in mitochondrial tRNA Arg gene associated with non-dystrophic myotonias. Acta Neurol Belg 2020; 120:573-580. [PMID: 30430429 DOI: 10.1007/s13760-018-1042-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/04/2018] [Indexed: 11/28/2022]
Abstract
Non-dystrophic myotonias (NDM) are rare diseases caused by defects in skeletal muscle chloride and sodium ion channels. It is well established that high-energy consuming tissues such as muscular and nervous systems are exclusively dependent on the ATP generation by mitochondria. The mitochondrial dysfunction, which is caused by mitochondrial DNA mutations, played an important role in the pathogenesis of non-dystrophic myotonias. The purpose of this study is to identify mitochondrial tRNA mutations in non-dystrophic myotonias patients. In this study, 45 Iranian patients with non-dystrophic myotonia were investigated for intracellular ATP content and the mutation screening in all the mitochondrial tRNA genes by DNA sequencing. Our findings showed that lymphocyte intracellular ATP is significantly decreased in NDM patients compared with control subjects (p = 0.001). We found nine mutations in mitochondrial tRNA genes, including m.4454 T > C (in the TψC loop of tRNAMet), m.5568 A > G (tRNATrp), m.5794 T > C (in the anticodon loop of tRNACys), novel m.10438 A > T, and m.10462 T > C (in anticodon loop and ACC stem of tRNAArg), m.12308 A > G (tRNALeu(CUN)) and m.15907 A > G, m.15924 A > G, and m.15928 G > A (in the anticodon stem of tRNAThr) in 31 NDM patients. These results suggest that novel m.10438 A > T mutation is involved in NDM patients and reinforces the significant association between this mutation in mitochondrial tRNAArg Gene and NDM patients (p = 0.008).
Collapse
Affiliation(s)
| | | | | | - Azam Khosravi
- Department of Biology, School of Science, Yazd University, Yazd, Iran
| | - Zeinab Bandari
- Department of Biology, School of Science, Yazd University, Yazd, Iran
| | - Mehri Khatami
- Department of Biology, School of Science, Yazd University, Yazd, Iran
| | - Shahriar Nafissi
- Department of Neurology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
8
|
Raja Rayan DL, Hanna MG. Managing pregnancy and anaesthetics in patients with skeletal muscle channelopathies. Neuromuscul Disord 2020; 30:539-545. [PMID: 32622512 DOI: 10.1016/j.nmd.2020.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/14/2020] [Accepted: 05/22/2020] [Indexed: 11/15/2022]
Abstract
The skeletal muscle channelopathies are a group of rare diseases and include non-dystrophic myotonia and periodic paralysis. Given their rarity, little has been published on the management of anaesthesia and pregnancy in this cohort despite being important aspects of care. We have conducted a large study of over 70 patients who underwent anaesthesia and 87 pregnancies to investigate the problems encountered following anaesthesia or during pregnancy. This was performed via patient surveys sent out to genetically confirmed channelopathy patients seen at the National Hospital for Neurology and Neurosurgery. Most significantly in our cohort, patients frequently experienced a worsening or precipitation of symptoms during pregnancy (75%) or following anaesthetic (31%). None of our patients developed malignant hyperthermia, although there are confirmed reports of this in patients with periodic paralysis and mutations in RYR1. There was a significantly higher number of miscarriages compared to the normal population. There was no significant difference in antenatal or delivery complications compared to the general population. However, three neonates did have complications, all of whom were found to carry mutations in SCN4A. This study highlights the importance of counselling patients and clinicians for the possibility of worsening symptoms during pregnancy or anaesthesia and the careful management of neonates following delivery.
Collapse
Affiliation(s)
- Dipa L Raja Rayan
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK.
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| |
Collapse
|
9
|
Barghouthi T, Lemley R, Figurelle M, Bushnell C. Epidemiology of neurologic disease in pregnancy. HANDBOOK OF CLINICAL NEUROLOGY 2020; 171:119-141. [PMID: 32736746 DOI: 10.1016/b978-0-444-64239-4.00006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Many neurologic diseases in women are influenced by the physiologic and hormonal changes of pregnancy, and pregnancy itself poses challenges in both treatment and evaluation of these conditions. Some diseases, such as epilepsy and multiple sclerosis, have a high enough prevalence in the young female population to support robust epidemiologic data while many other neurologic diseases, such as specific myopathies and muscular dystrophies, have a low prevalence, with data limited to case reports and small case series. This chapter features epidemiologic information regarding a breadth of neurologic conditions, including stroke, epilepsy, demyelinating disease, peripheral neuropathies, migraine, sleep-disordered breathing, and meningioma, in women in the preconception, pregnancy, and postpartum stages.
Collapse
Affiliation(s)
- Tamara Barghouthi
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC, United States
| | - Regan Lemley
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC, United States
| | - Morgan Figurelle
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC, United States
| | - Cheryl Bushnell
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC, United States.
| |
Collapse
|