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Uncini A, Cavallaro T, Fabrizi GM, Manganelli F, Vallat JM. Conduction slowing, conduction block and temporal dispersion in demyelinating, dysmyelinating and axonal neuropathies: Electrophysiology meets pathology. J Peripher Nerv Syst 2024. [PMID: 38600691 DOI: 10.1111/jns.12625] [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: 01/23/2024] [Revised: 03/02/2024] [Accepted: 03/28/2024] [Indexed: 04/12/2024]
Abstract
Nerve conduction studies are usually the first diagnostic step in peripheral nerve disorders and their results are the basis for planning further investigations. However, there are some commonplaces in the interpretation of electrodiagnostic findings in peripheral neuropathies that, although useful in the everyday practice, may be misleading: (1) conduction block and abnormal temporal dispersion are distinctive features of acquired demyelinating disorders; (2) hereditary neuropathies are characterized by uniform slowing of conduction velocity; (3) axonal neuropathies are simply diagnosed by reduced amplitude of motor and sensory nerve action potentials with normal or slightly slow conduction velocity. In this review, we reappraise the occurrence of uniform and non-uniform conduction velocity slowing, conduction block and temporal dispersion in demyelinating, dysmyelinating and axonal neuropathies attempting, with a translational approach, a correlation between electrophysiological and pathological features as derived from sensory nerve biopsy in patients and animal models. Additionally, we provide some hints to navigate in this complex field.
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Affiliation(s)
- Antonino Uncini
- Department of Neurosciences, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti-Pescara, Italy
| | - Tiziana Cavallaro
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy
| | - Gian Maria Fabrizi
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Naples, Italy
| | - Jean-Michel Vallat
- Department of Neurology, National Reference Center for "Rare Peripheral Neuropathies", CHU Dupuytren, Limoges, France
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Identification and clinical characterization of Charcot-Marie-Tooth disease type 1C patients with LITAF p.G112S mutation. Genes Genomics 2022; 44:1007-1016. [PMID: 35608774 DOI: 10.1007/s13258-022-01253-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/30/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare subtype associated with LITAF gene mutations. Until now, only a few studies have reported the clinical features of CMT1C. OBJECTIVE This study was performed to find CMT1C patients with mutation of LITAF in a Korean CMT cohort and to characterize their clinical features. METHODS In total, 1,143 unrelated Korean families with CMT were enrolled in a cohort. We performed whole exome sequencing to identify LITAF mutations, and examined clinical phenotypes including electrophysiological and MRI features for the identified CMT1C patients. RESULTS We identified 10 CMT1C patients from three unrelated families with p.G112S mutation in LITAF. The frequency of CMT1C among CMT1 patients was 0.59%, which is similar to reports from Western populations. CMT1C patients showed milder symptoms than CMT1A patients. The mean CMT neuropathy score version 2 was 7.7, and the mean functional disability scale was 1.0. Electrophysiological findings showed a conduction block in 22% of affected individuals. Lower extremity MRIs showed that the superficial posterior and anterolateral compartments of the calf were predominantly affected. CONCLUSIONS We found a conduction block in Korean CMT1C patients with p.G112S mutation and first described the characteristic MRI findings of the lower extremities in patients with LITAF mutation. These findings will be helpful for genotype-phenotype correlation and will widen understanding about the clinical spectrum of CMT1C.
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Nagappa M, Sharma S, Govindaraj P, Chickabasaviah Y, Siram R, Shroti A, Seshagiri D, Debnath M, Bindu P, Taly A. Genetic spectrum of inherited neuropathies in India. Ann Indian Acad Neurol 2022; 25:407-416. [PMID: 35936615 PMCID: PMC9350795 DOI: 10.4103/aian.aian_269_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 11/17/2022] Open
Abstract
Background and Objectives: Charcot-Marie-Tooth (CMT) disease is the commonest inherited neuromuscular disorder and has heterogeneous manifestations. Data regarding genetic basis of CMT from India is limited. This study aims to report the variations by using high throughput sequencing in Indian CMT cohort. Methods: Fifty-five probands (M:F 29:26) with suspected inherited neuropathy underwent genetic testing (whole exome: 31, clinical exome: 17 and targeted panel: 7). Their clinical and genetic data were analysed. Results: Age at onset ranged from infancy to 54 years. Clinical features included early-onset neuropathy (n=23), skeletal deformities (n=45), impaired vision (n=8), impaired hearing (n=6), facial palsy (n=8), thickened nerves (n=4), impaired cognition (n=5), seizures (n=5), pyramidal signs (n=7), ataxia (n=8) and vocal cord palsy, slow tongue movements and psychosis in one patient each. Twenty-eight patients had demyelinating electrophysiology. Abnormal visual and auditory evoked potentials were noted in 60.60% and 37.5% respectively. Sixty two variants were identified in 37 genes including variants of uncertain significance (n=34) and novel variants (n=45). Eleven patients had additional variations in genes implicated in CMTs/ other neurological disorders. Ten patients did not have variations in neuropathy associated genes, but had variations in genes implicated in other neurological disorders. In seven patients, no variations were detected. Conclusion: In this single centre cohort study from India, genetic diagnosis could be established in 87% of patients with inherited neuropathy. The identified spectrum of genetic variations adds to the pool of existing data and provides a platform for validation studies in cell culture or animal model systems.
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Fernandez-Garcia MA, Stettner GM, Kinali M, Clarke A, Fallon P, Knirsch U, Wraige E, Jungbluth H. Genetic neuropathies presenting with CIDP-like features in childhood. Neuromuscul Disord 2021; 31:113-122. [PMID: 33386210 DOI: 10.1016/j.nmd.2020.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 12/15/2022]
Abstract
Inherited neuropathies are amongst the most common neuromuscular disorders. The distinction from chronic inflammatory demyelinating polyneuropathy (CIDP) may be challenging, considering its rarity in childhood, that genetic neuropathies may show secondary inflammatory features, and that subacute CIDP presentations may closely mimic the disease course of inherited disorders. The overlap between genetic neuropathies and CIDP is increasingly recognized in adults but rarely reported in children. Here we report 4 children with a neuropathy of subacute onset, initially considered consistent with an immune-mediated neuropathy based on suggestive clinical, laboratory and neurophysiological features. None showed convincing response to intravenous immunoglobulin therapy, leading to re-evaluation and confirmation of a genetic neuropathy in each case (including PMP22, MPZ and SH3TC2 genes). A review of the few Paediatric cases reported in the literature showed similar delays in diagnosis and no significant changes to immunomodulatory treatment. Our findings emphasize the importance of considering an inherited neuropathy in children with a CIDP-like presentation. In addition to an inconclusive response to treatment, subtle details of the family and developmental history may indicate a genetic rather than an acquired background. Correct diagnostic confirmation of a genetic neuropathy in a child is crucial for appropriate management, prognostication and genetic counselling.
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Affiliation(s)
- Miguel A Fernandez-Garcia
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, F02 - Becket House, Lambeth Palace Road, London SE1 7EU, United Kingdom
| | - Georg M Stettner
- Division of Paediatric Neurology, University Children´s Hospital Zurich, Zurich, Switzerland
| | - Maria Kinali
- Department of Paediatric Neurology, The Portland Hospital, HCA Healthcare, United Kingdom; Imperial College, London, United Kingdom
| | - Antonia Clarke
- Department of Paediatric Neurosciences, St George's University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Penny Fallon
- Department of Paediatric Neurosciences, St George's University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Ursula Knirsch
- Division of Paediatric Neurology, University Children´s Hospital Zurich, Zurich, Switzerland
| | - Elizabeth Wraige
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, F02 - Becket House, Lambeth Palace Road, London SE1 7EU, United Kingdom
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, F02 - Becket House, Lambeth Palace Road, London SE1 7EU, United Kingdom; Muscle Signalling Section, Randall Division for Cell and Molecular Biophysics, King's College, London, United Kingdom; Department of Basic and Clinical Neuroscience, King's College, IoPPN, London, United Kingdom.
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Abstract
Introduction: Carpal tunnel syndrome and ulnar neuropathy are such common maladies affecting the upper extremties that they often become the default diagnosis when patients complain of numbness, pain, or weakness of the hands. While often correct, there are a number of other conditions that can also cause sensory or motor loss of the hands, which should be considered when appropriate, as they can mimic upper extremity entrapment syndromes. Methods: In this review, we will discuss such mimics, including Charcot-Marie-Tooth disease, multifocal motor neuropathy, hereditary neuropathy with pressure palsies, mononeuropathy multiplex, Lewis-Sumner syndrome, brachial plexitis (Parsonage-Turner syndrome), myotonic dystrophy, inclusion body myopathy, and distal myopathy of Welander. We will discuss the clinical presentation, as well as diagnostic testing, treatment (if available), and prognosis. Conclusion: The objective is to provide a differential diagnosis for those patients who do not fit well clinically or respond to usual therapy for entrapment neuropathy of the upper extremities.
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Affiliation(s)
- James M. Gilchrist
- Southern Illinois University School of Medicine, Springfield, USA,James M. Gilchrist, Department of Neurology, Southern Illinois University School of Medicine, 751 N. Rutledge Street, PO Box 19643, Springfield, IL 62794, USA.
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Spiesshoefer J, Henke C, Kabitz H, Akova‐Oeztuerk E, Draeger B, Herkenrath S, Randerath W, Young P, Brix T, Boentert M. Phrenic nerve involvement and respiratory muscle weakness in patients with Charcot‐Marie‐Tooth disease 1A. J Peripher Nerv Syst 2019; 24:283-293. [DOI: 10.1111/jns.12341] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/13/2019] [Accepted: 08/05/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Jens Spiesshoefer
- Respiratory Physiology Laboratory, Department of Neurology, University of Münster Münster Germany
| | - Carolin Henke
- Respiratory Physiology Laboratory, Department of Neurology, University of Münster Münster Germany
| | - Hans‐Joachim Kabitz
- Department of PneumologyCardiology and Intensive Care Medicine, Klinikum Konstanz Konstanz Germany
| | - Esra Akova‐Oeztuerk
- Respiratory Physiology Laboratory, Department of Neurology, University of Münster Münster Germany
| | - Bianca Draeger
- Respiratory Physiology Laboratory, Department of Neurology, University of Münster Münster Germany
| | - Simon Herkenrath
- Bethanien Hospital gGmbH Solingen Solingen Germany
- Institute for Pneumology at the University of Cologne Cologne Germany
| | - Winfried Randerath
- Bethanien Hospital gGmbH Solingen Solingen Germany
- Institute for Pneumology at the University of Cologne Cologne Germany
| | | | - Tobias Brix
- Institute of Medical Informatics, University of Münster Münster Germany
| | - Matthias Boentert
- Respiratory Physiology Laboratory, Department of Neurology, University of Münster Münster Germany
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Shy ME. Reply: The classification of Charcot-Marie-Tooth diseases, a never-ending story: CMT4? Brain 2019; 141:e71. [PMID: 30084871 DOI: 10.1093/brain/awy208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, 200 Hawkins Drive, Iowa City Iowa, USA
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Tracy JA, Dyck PJ, Klein CJ, Engelstad JK, Meyer JE, Dyck PJB. Onion-bulb patterns predict acquired or inherited demyelinating polyneuropathy. Muscle Nerve 2019; 59:665-670. [PMID: 30810227 DOI: 10.1002/mus.26452] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/23/2019] [Accepted: 02/23/2019] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Onion-bulbs (OB) are concentrically layered Schwann-cell processes, surrounding nerve fibers, occurring in both inherited and acquired demyelinating polyneuropathies. We investigated whether OB patterns (generalized, mixed, or focal) correlate with acquired or inherited neuropathies. METHODS One hundred thirty-one OB-rich nerve biopsies were graded for OB pattern and inflammation without knowledge of clinical history. We classified inherited (n = 49) or acquired (n = 82) neuropathies based solely on clinical history. RESULTS Fifty-one biopsies had generalized (34 inherited vs. 17 acquired, P < 0.001), 54 mixed (48 acquired vs. 6 inherited, P < 0.001), and 26 focal/multifocal (inherited [n = 9], acquired [n = 17]) OB. Inflammation occurred more frequently in acquired (n = 54) than inherited (n = 14) neuropathy (P = 0.004). DISCUSSION Generalized OB correlates with inherited neuropathy; mixed OB with acquired. Inflammation occurs more in acquired neuropathy cases. OB patterns are best explained by ubiquitous Schwann-cell involvement in inherited and multifocal Schwann-cell involvement in acquired neuropathies and predict the electrophysiology of uniform demyelination in inherited and unequal demyelination in acquired neuropathies. Muscle Nerve 59:665-670, 2019.
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Affiliation(s)
- Jennifer A Tracy
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
| | - Peter J Dyck
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
| | - Christopher J Klein
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
| | - JaNean K Engelstad
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
| | - Jane E Meyer
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
| | - P James B Dyck
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905, USA
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Kanhangad M, Cornett K, Brewer MH, Nicholson GA, Ryan MM, Smith RL, Subramanian GM, Young HK, Züchner S, Kennerson ML, Burns J, Menezes MP. Unique clinical and neurophysiologic profile of a cohort of children with CMTX3. Neurology 2018; 90:e1706-e1710. [PMID: 29626178 PMCID: PMC10681066 DOI: 10.1212/wnl.0000000000005479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 02/21/2018] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To describe in detail the clinical profile of Charcot-Marie-Tooth disease subtype 3 (CMTX3) to aid appropriate genetic testing and rehabilitative therapy. METHODS We reviewed the clinical and neurophysiologic profile and CMT Pediatric Scale (CMTPedS) assessments of 11 children with CMTX3. RESULTS Compared with the more common forms of CMT, CMT1A and CMTX, CMTX3 was characterized by early onset with early and progressive hand weakness. Most affected children were symptomatic within the first 2 years of life. The most common presentation was foot deformity in the first year of life. CMTPedS analysis in these children revealed that CMTX3 progressed more rapidly (4.3 ± 4.1 points over 2 years, n = 7) than CMT1A and CMTX1. Grip strength in affected boys was 2 SDs below age- and sex-matched normative reference values (z score -2.05 ± 1.32) in the second decade of life. The most severely affected individual was wheelchair bound at 14 years of age, and 2 individuals had no movement in the small muscles of the hand in the second decade of life. Nerve conduction studies showed a demyelinating sensorimotor neuropathy with motor conduction velocity ≤23 m/s. CONCLUSIONS CMTX3 had an earlier onset, severe hand weakness, and more rapidly progressive disability compared to the more common forms of CMT. Understanding the unique phenotype of CMTX3 is essential for directing genetic testing because the CMTX3 insertion will not be seen on a routine microarray or neuromuscular gene panel. Early diagnosis will enable rehabilitation to be started early in this rapidly progressive neuropathy.
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Affiliation(s)
- Manoj Kanhangad
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Kayla Cornett
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Megan H Brewer
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Garth A Nicholson
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Monique M Ryan
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Robert L Smith
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Gopinath M Subramanian
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Helen K Young
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Stephan Züchner
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Marina L Kennerson
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Joshua Burns
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia
| | - Manoj P Menezes
- From the T.Y. Nelson Department of Neurology and Neurosurgery (M.K., M.P.M.) and Institute for Neuroscience and Muscle Research (K.C., J.B., M.P.M.), The Children's Hospital at Westmead; University of Sydney (K.C., M.H.B., G.A.N., H.K.Y., M.L.K., J.B., M.P.M.); Northcott Neuroscience Laboratory (M.H.B., G.A.N., M.L.K.), ANZAC Research Institute, Concord; Molecular Medicine Laboratory (G.A.N., M.L.K.), Concord Repatriation General Hospital, New South Wales; Department of Neurology (M.M.R.), Royal Children's Hospital; Murdoch Children's Research Institute (M.M.R.); Department of Paediatrics (M.M.R.), University of Melbourne, Parkville, Victoria; Department of Neurology (R.L.S., G.M.S.), John Hunter Children's Hospital, and University Faculty of Health, Newcastle; Department of Paediatrics (H.K.Y.), Royal North Shore Hospital, St. Leonards, New South Wales, Australia; Department of Human Genetics (S.Z.), Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, FL; and Paediatric Gait Analysis Service of New South Wales (J.B.), Sydney Children's Hospitals Network (Randwick and Westmead), Australia.
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Hu B, McCollum M, Ravi V, Arpag S, Moiseev D, Castoro R, Mobley B, Burnette B, Siskind C, Day J, Yawn R, Feely S, Li Y, Yan Q, Shy M, Li J. Myelin abnormality in Charcot-Marie-Tooth type 4J recapitulates features of acquired demyelination. Ann Neurol 2018. [PMID: 29518270 DOI: 10.1002/ana.25198] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Charcot-Marie-Tooth type 4J (CMT4J) is a rare autosomal recessive neuropathy caused by mutations in FIG4 that result in loss of FIG4 protein. This study investigates the natural history and mechanisms of segmental demyelination in CMT4J. METHODS Over the past 9 years, we have enrolled and studied a cohort of 12 CMT4J patients, including 6 novel FIG4 mutations. We evaluated these patients and related mouse models using morphological, electrophysiological, and biochemical approaches. RESULTS We found sensory motor demyelinating polyneuropathy consistently in all patients. This underlying myelin pathology was associated with nonuniform slowing of conduction velocities, conduction block, and temporal dispersion on nerve conduction studies, which resemble those features in acquired demyelinating peripheral nerve diseases. Segmental demyelination was also confirmed in mice without Fig4 (Fig4-/- ). The demyelination was associated with an increase of Schwann cell dedifferentiation and macrophages in spinal roots where nerve-blood barriers are weak. Schwann cell dedifferentiation was induced by the increasing intracellular Ca2+ . Suppression of Ca2+ level by a chelator reduced dedifferentiation and demyelination of Schwann cells in vitro and in vivo. Interestingly, cell-specific knockout of Fig4 in mouse Schwann cells or neurons failed to cause segmental demyelination. INTERPRETATION Myelin change in CMT4J recapitulates the features of acquired demyelinating neuropathies. This pathology is not Schwann cell autonomous. Instead, it relates to systemic processes involving interactions of multiple cell types and abnormally elevated intracellular Ca2+ . Injection of a Ca2+ chelator into Fig4-/- mice improved segmental demyelination, thereby providing a therapeutic strategy against demyelination. Ann Neurol 2018;83:756-770.
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Affiliation(s)
- Bo Hu
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Megan McCollum
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Vignesh Ravi
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Sezgi Arpag
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Daniel Moiseev
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Ryan Castoro
- Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN
| | - Bret Mobley
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN
| | - Bryan Burnette
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Carly Siskind
- Department of Neurology, Stanford University, Palo Alto, CA
| | - John Day
- Department of Neurology, Stanford University, Palo Alto, CA
| | - Robin Yawn
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Shawna Feely
- Department of Neurology, University of Iowa, Iowa City, IA
| | - Yuebing Li
- Department of Neurology, Cleveland Clinic Foundation, Cleveland, OH
| | - Qing Yan
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN.,Department of Laboratory Medicine, Second Affiliated Hospital of Qingdao University, Qingdao, China
| | - Michael Shy
- Department of Neurology, University of Iowa, Iowa City, IA
| | - Jun Li
- Department of Neurology, Center for Human Genetic Research, and Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN.,Tennessee Valley Healthcare System-Nashville VA, Nashville, TN
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11
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Abstract
PURPOSE OF REVIEW This article provides core information on the clinical neurophysiology techniques available for the investigation of disorders of the peripheral nervous system. RECENT FINDINGS The role of small fiber dysfunction in some types of polyneuropathy is being increasingly appreciated, and neurophysiologic techniques for evaluating the autonomic components of peripheral axons have enhanced our understanding of small fiber dysfunction. SUMMARY The principles of nerve conduction studies and needle EMG are presented in this article, along with the patterns of abnormality encountered in patients with polyneuropathy due to large and small fiber involvement.
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12
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Jerath NU, Gutmann L, Reddy CG, Shy ME. Charcot-marie-tooth disease type 1X in women: Electrodiagnostic findings. Muscle Nerve 2016; 54:728-32. [PMID: 26873881 DOI: 10.1002/mus.25077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 01/31/2016] [Accepted: 02/10/2016] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Symptoms and signs in women with Charcot-Marie-Tooth disease type 1X (CMT1X) are often milder from those in men, but the available electrophysiologic evidence regarding CMT1X in women has been characterized in some patients as non-uniform or asymmetric. METHODS We retrospectively reviewed electrodiagnostic findings from 45 women and 31 men with CMT1X. RESULTS Motor nerve conduction parameters in CMT1X women were less abnormal (P < 0.05), and a wider range of motor conduction velocities (CVs) were seen in women (P < 0.001) compared with men. In women, nerve conduction studies showed lack of conduction block without temporal dispersion. Motor CVs were more frequently in the normal range in women compared with men. There was no significant relationship to age of presentation and motor CV or compound muscle action potential in women. CONCLUSION NCS parameters in CMT1X women did not demonstrate features suggestive of an acquired demyelinating neuropathy. Muscle Nerve, 2016 Muscle Nerve 54: -, 2016 Muscle Nerve 54: 728-732, 2016.
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Affiliation(s)
- Nivedita U Jerath
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa, 52242, USA.
| | - Laurie Gutmann
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa, 52242, USA
| | - Chandan G Reddy
- Department of Neurosurgery, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Michael E Shy
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa, 52242, USA
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13
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Oliveira APMD, Pereira RC, Onofre PT, Marques VD, Andrade GBD, Barreira AA, Marques Junior W. Clinical and neurophysiological features of the hereditary neuropathy with liability to pressure palsy due to the 17p11.2 deletion. ARQUIVOS DE NEURO-PSIQUIATRIA 2016; 74:99-105. [DOI: 10.1590/0004-282x20160010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/01/2015] [Indexed: 12/25/2022]
Abstract
ABSTRACT The hereditary neuropathy with liability to pressure palsies (HNPP) is an autossomal dominant disorder manifesting recurrent mononeuropathies. Objective Evaluate its clinical and nerve conduction studies (NCS) characteristics, searching for diagnostic particularities. Method We reviewed the neurological manifestations of 39 and the NCS of 33 patients. Results Family history was absent in 16/39 (41%). The onset complaints were weakness in 24, pain in 6, sensory deficit in 5 and paresthesias in 4. Pain was seen in 3 other patients. The following neuropathy patterns were found: multiple mononeuropathy (26), mononeuropathy (7), chronic sensorimotor polyneuropathy (4), chronic sensory polyneuropathy (1) and unilateral brachial plexopathy (1). NCS showed a sensorimotor neuropathy with focal conduction slowing in 31, two had mononeuropathy and another brachial plexopathy. Conclusion HNPP presentation is variable and may include pain. The most frequent pattern is of an asymmetrical sensory and motor neuropathy with focal slowing at specific topographies on NCS.
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14
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Abstract
Neonatal hypotonia is a common problem in the neonatal intensive care unit. The genetic differential diagnosis is broad, encompassing primary muscular dystrophies, chromosome abnormalities, neuropathies, and inborn errors of metabolism. Recognition of hypotonia is relatively straightforward, but determining the cause can be challenging. It is important for the neonatologist to have an organized approach to the assessment of neonatal hypotonia. Physical examination and history alongside basic laboratory testing and imaging aid in the differential diagnosis. Identification of the cause is essential for determining prognosis, associated morbidities, and recurrence risk. The prevailing therapeutic modality is physical, occupational, speech/feeding, and respiratory therapy.
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Affiliation(s)
- Susan E Sparks
- Department of Pediatrics, Carolinas Healthcare System, 1000 Blythe Boulevard, Charlotte, NC 28203, USA.
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15
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Li J. Molecular regulators of nerve conduction - Lessons from inherited neuropathies and rodent genetic models. Exp Neurol 2015; 267:209-18. [PMID: 25792482 DOI: 10.1016/j.expneurol.2015.03.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 11/15/2022]
Abstract
Myelinated nerve fibers are highly compartmentalized. Helically wrapped lipoprotein membranes of myelin are integrated with subsets of proteins specifically in each compartment to shape the physiological behavior of these nerve fibers. With the advance of molecular biology and genetics, many functions of these proteins have been revealed over the past decade. In this review, we will first discuss how action potential propagation has been understood by classical electrophysiological studies. In particular, the discussion will be concentrated on how the geometric dimensions of myelinated nerve fibers (such as internodal length and myelin thickness) may affect nerve conduction velocity. This discussion will then extend into how specific myelin proteins may shape these geometric parameters, thereby regulating action potential propagation. For instance, periaxin may specifically affect the internodal length, but not other parameters. In contrast, neuregulin-1 may affect myelin thickness, but not axon diameter or internodal length. Finally, we will discuss how these basic neurobiological observations can be applied to inherited peripheral nerve diseases.
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Affiliation(s)
- Jun Li
- Department of Neurology, Center for Human Genetic Research, Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA; Tennessee Valley Healthcare System, Nashville VA, Nashville, TN, USA.
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16
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Goedee SH, Brekelmans GJF, van den Berg LH, Visser LH. Distinctive patterns of sonographic nerve enlargement in Charcot-Marie-Tooth type 1A and hereditary neuropathy with pressure palsies. Clin Neurophysiol 2014; 126:1413-20. [PMID: 25454274 DOI: 10.1016/j.clinph.2014.08.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/06/2014] [Accepted: 08/29/2014] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The extent of sonomorphologic differences of peripheral nerves between CMT and HNPP is unknown. METHODS We recruited 9 patients with CMT-1A and 9 with HNPP. Patients underwent a standardized sonographic protocol, which evaluated nerve size and vascularization. We quantitatively assessed fascicle size and echogenicity. RESULTS All 18 patients demonstrated nerve enlargement, but no increased vascularization. HNPP demonstrated larger nerves at sites of entrapment (median nerve at the carpal tunnel p=0.049, ulnar nerve at the sulcus p<0.001), greater swelling ratios of median (p<0.001), ulnar (p=0.017) and fibular nerve (p=0.005) than CMT-1A. CMT-1A revealed larger nerves proximal to sites of entrapment (median and fibular nerve, brachial plexus p<0.001). Nerve fascicles where larger (p<0.001) and more hypo-echogenic in CMT-1A. Nerve, fascicle size nor echogenicity correlated with age, gender or MRC sum-score. CONCLUSIONS Ultrasonography of nerves reveals specific phenotypes differentiating CMT-1A from HNPP. In CMT-1A enlargement of nerves and fascicles is multifocal among multiple nerves, whereas in HNPP nerve enlargement is restricted to sites of entrapment. SIGNIFICANCE Our findings of specific sonomorphological phenotypes, differentiating CMT-1A from HNPP, may help to improve our pathophysiological insights in CMT and HNPP.
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Affiliation(s)
- Stephan H Goedee
- Department of Neurology, UMC Utrecht, Utrecht, The Netherlands; Brain Center Rudolf Magnus, Department of Neuroscience, UMC Utrecht, Utrecht, The Netherlands.
| | - Geert J F Brekelmans
- Department of Neurology, St. Elisabeth Hospital, Tilburg, The Netherlands; Department of Clinical Neurophysiology, St. Elisabeth Hospital, Tilburg, The Netherlands
| | - Leonard H van den Berg
- Department of Neurology, UMC Utrecht, Utrecht, The Netherlands; Brain Center Rudolf Magnus, Department of Neuroscience, UMC Utrecht, Utrecht, The Netherlands
| | - Leo H Visser
- Department of Neurology, St. Elisabeth Hospital, Tilburg, The Netherlands; Department of Clinical Neurophysiology, St. Elisabeth Hospital, Tilburg, The Netherlands
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17
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Dortch RD, Dethrage LM, Gore JC, Smith SA, Li J. Proximal nerve magnetization transfer MRI relates to disability in Charcot-Marie-Tooth diseases. Neurology 2014; 83:1545-53. [PMID: 25253751 DOI: 10.1212/wnl.0000000000000919] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE The objectives of this study were (1) to develop a novel magnetization transfer ratio (MTR) MRI assay of the proximal sciatic nerve (SN), which is inaccessible via current tools for assessing peripheral nerves, and (2) to evaluate the resulting MTR values as a potential biomarker of myelin content changes in patients with Charcot-Marie-Tooth (CMT) diseases. METHODS MTR was measured in the SN of patients with CMT type 1A (CMT1A, n = 10), CMT type 2A (CMT2A, n = 3), hereditary neuropathy with liability to pressure palsies (n = 3), and healthy controls (n = 21). Additional patients without a genetically confirmed subtype (n = 4), but whose family histories and electrophysiologic tests were consistent with CMT, were also included. The relationship between MTR and clinical neuropathy scores was assessed, and the interscan and inter-rater reliability of MTR was estimated. RESULTS Mean volumetric MTR values were significantly decreased in the SN of patients with CMT1A (33.8 ± 3.3 percent units) and CMT2A (31.5 ± 1.9 percent units) relative to controls (37.2 ± 2.3 percent units). A significant relationship between MTR and disability scores was also detected (p = 0.01 for genetically confirmed patients only, p = 0.04 for all patients). From interscan and inter-rater reliability analyses, proximal nerve MTR values were repeatable at the slicewise and mean volumetric levels. CONCLUSIONS MTR measurements may be a viable biomarker of proximal nerve pathology in patients with CMT.
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Affiliation(s)
- Richard D Dortch
- From the Department of Radiology and Radiological Sciences (R.D.D., J.C.G., S.A.S.), Vanderbilt University Institute of Imaging Science (R.D.D., L.M.D., J.C.G., S.A.S.), and the Departments of Biomedical Engineering (R.D.D., J.C.G., S.A.S.), Physics and Astronomy (J.C.G., S.A.S.), Molecular Physiology and Biophysics (J.C.G.), and Neurology (J.L.), Vanderbilt University, Nashville, TN.
| | - Lindsey M Dethrage
- From the Department of Radiology and Radiological Sciences (R.D.D., J.C.G., S.A.S.), Vanderbilt University Institute of Imaging Science (R.D.D., L.M.D., J.C.G., S.A.S.), and the Departments of Biomedical Engineering (R.D.D., J.C.G., S.A.S.), Physics and Astronomy (J.C.G., S.A.S.), Molecular Physiology and Biophysics (J.C.G.), and Neurology (J.L.), Vanderbilt University, Nashville, TN
| | - John C Gore
- From the Department of Radiology and Radiological Sciences (R.D.D., J.C.G., S.A.S.), Vanderbilt University Institute of Imaging Science (R.D.D., L.M.D., J.C.G., S.A.S.), and the Departments of Biomedical Engineering (R.D.D., J.C.G., S.A.S.), Physics and Astronomy (J.C.G., S.A.S.), Molecular Physiology and Biophysics (J.C.G.), and Neurology (J.L.), Vanderbilt University, Nashville, TN
| | - Seth A Smith
- From the Department of Radiology and Radiological Sciences (R.D.D., J.C.G., S.A.S.), Vanderbilt University Institute of Imaging Science (R.D.D., L.M.D., J.C.G., S.A.S.), and the Departments of Biomedical Engineering (R.D.D., J.C.G., S.A.S.), Physics and Astronomy (J.C.G., S.A.S.), Molecular Physiology and Biophysics (J.C.G.), and Neurology (J.L.), Vanderbilt University, Nashville, TN
| | - Jun Li
- From the Department of Radiology and Radiological Sciences (R.D.D., J.C.G., S.A.S.), Vanderbilt University Institute of Imaging Science (R.D.D., L.M.D., J.C.G., S.A.S.), and the Departments of Biomedical Engineering (R.D.D., J.C.G., S.A.S.), Physics and Astronomy (J.C.G., S.A.S.), Molecular Physiology and Biophysics (J.C.G.), and Neurology (J.L.), Vanderbilt University, Nashville, TN
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18
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Abstract
Chronic neuropathies are operationally classified as primarily demyelinating or axonal, on the basis of electrodiagnostic or pathological criteria. Demyelinating neuropathies are further classified as hereditary or acquired-this distinction is important, because the acquired neuropathies are immune-mediated and, thus, amenable to treatment. The acquired chronic demyelinating neuropathies include chronic inflammatory demyelinating polyneuropathy (CIDP), neuropathy associated with monoclonal IgM antibodies to myelin-associated glycoprotein (MAG; anti-MAG neuropathy), multifocal motor neuropathy (MMN), and POEMS syndrome. They have characteristic--though overlapping--clinical presentations, are mediated by distinct immune mechanisms, and respond to different therapies. CIDP is the default diagnosis if the neuropathy is demyelinating and no other cause is found. Anti-MAG neuropathy is diagnosed on the basis of the presence of anti-MAG antibodies, MMN is characterized by multifocal weakness and motor conduction blocks, and POEMS syndrome is associated with IgG or IgA λ-type monoclonal gammopathy and osteosclerotic myeloma. The correct diagnosis, however, can be difficult to make in patients with atypical or overlapping presentations, or nondefinitive laboratory studies. First-line treatments include intravenous immunoglobulin (IVIg), corticosteroids or plasmapheresis for CIDP; IVIg for MMN; rituximab for anti-MAG neuropathy; and irradiation or chemotherapy for POEMS syndrome. A correct diagnosis is required for choosing the appropriate treatment, with the aim of preventing progressive neuropathy.
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Affiliation(s)
- Norman Latov
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 1305 York Avenue, Suite 217, New York, NY 10021, USA
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19
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El-Abassi R, England JD, Carter GT. Charcot-Marie-Tooth disease: an overview of genotypes, phenotypes, and clinical management strategies. PM R 2014; 6:342-55. [PMID: 24434692 DOI: 10.1016/j.pmrj.2013.08.611] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 08/10/2013] [Accepted: 08/31/2013] [Indexed: 11/30/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease, which encompasses several hereditary motor and sensory neuropathies, is one of the most common neuromuscular disorders. Our understanding of the molecular genotypes of CMT and the resultant clinical and electrophysiological phenotypes has increased greatly in the past decade. Characterized by electrodiagnostic studies into demyelinating (type 1) and axonal (type 2) forms, subsequent genetic testing often provides an exact diagnosis of a specific subtype of CMT. These advancements have made diagnostic paradigms fairly straightforward. Still, the nature and extent of neuromuscular disability is often complex in persons with CMT, and no curative treatments are yet available. Genotypically homologous animal models of CMT have improved exploration of disease-modifying treatments, of which molecular genetic manipulation and stem cell therapies appear to be the most promising. Research is also needed to develop better rehabilitative strategies that may limit disease burden and improve physical performance and psychosocial integration. Clinical management should be multidisciplinary, including neurologists, physiatrists, neurogeneticists, neuromuscular nurse practitioners, and orthopedists, along with physical and occupational therapists, speech-language pathologists, orthotists, vocational counselors, social workers, and other rehabilitation clinicians. Goals should include maximizing functional independence and quality of life while minimizing disability and secondary morbidity.
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Affiliation(s)
- Rima El-Abassi
- Department of Neurology at the Louisiana State University School of Medicine, New Orleans, LA(∗)
| | - John D England
- Department of Neurology at the Louisiana State University School of Medicine, New Orleans, LA(†)
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Kang JH, Kim HJ, Lee ER. Electrophysiological evaluation of chronic inflammatory demyelinating polyneuropathy and charcot-marie-tooth type 1: dispersion and correlation analysis. J Phys Ther Sci 2013; 25:1265-8. [PMID: 24259772 PMCID: PMC3820196 DOI: 10.1589/jpts.25.1265] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 05/20/2013] [Indexed: 12/14/2022] Open
Abstract
[Purpose] The purpose of this study was to analyze and compare electrophysiological characteristics observed in nerve conduction studies (NCS) of chronic inflammatory demyelinating polyneuropathy (CIDP) and Charcot-Marie-Tooth disease type 1 (CMT 1). [Subjects] A differential diagnosis of acquired and congenital demyelinating neuropathies was based on a study of 35 patients with NCS-confirmed CIDP and 30 patients with CMT 1 genetically proven by peripheral myelin protein-22 (PMP-22) gene analysis, pulsed-field gel electrophoresis (PFGE), and Southern blot analysis. [Methods] We analyzed values collected in motor nerve conduction studies. We conducted dispersion analysis of the amplitudes of the compound muscle action potential (CMAP) of various nerve types and correlation coefficient analysis of the motor nerve conduction velocity (MNCV). [Results] We found that CIDP and CMT 1 were clearly attributable to severe polyneuropathy. In dispersion analysis, CIDP showed greater differences in proximal-to-distal amplitude ratios. Moreover, CMT 1 showed relatively high correlations compared to CIDP based on correlation coefficient analysis of MNCV. [Conclusion] The results of this study suggest that CIDP showed greater asymmetry than CMT 1 in MNCV and CMAP amplitudes.
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Affiliation(s)
- Ji Hyuk Kang
- Department of Biomedical Laboratory Science, College of Health, Kyungwoon University, Republic of Korea
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Sagnelli A, Piscosquito G, Pareyson D. Inherited neuropathies: an update. J Neurol 2013; 260:2684-90. [PMID: 24061768 DOI: 10.1007/s00415-013-7113-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 01/21/2023]
Abstract
In this review, progress in hereditary neuropathy research published in the Journal of Neurology over the last 18 months is summarised.
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Affiliation(s)
- Anna Sagnelli
- Clinic of Central and Peripheral Degenerative Neuropathies Unit, Department of Clinical Neurosciences, IRCCS Foundation, "C. Besta" Neurological Institute, via Celoria 11, 20133, Milan, Italy
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Van den Bergh PY, Rajabally YA. Chronic inflammatory demyelinating polyradiculoneuropathy. Presse Med 2013; 42:e203-15. [DOI: 10.1016/j.lpm.2013.01.056] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/25/2013] [Accepted: 01/25/2013] [Indexed: 12/12/2022] Open
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Functional recovery of regenerating motor axons is delayed in mice heterozygously deficient for the myelin protein P(0) gene. Neurochem Res 2013; 38:1266-77. [PMID: 23564290 DOI: 10.1007/s11064-013-1030-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 03/06/2013] [Accepted: 03/26/2013] [Indexed: 10/27/2022]
Abstract
Mice with a heterozygous knock-out of the myelin protein P0 gene (P0+/-) develop a neuropathy similar to human Charcot-Marie-Tooth disease. They are indistinguishable from wild-types (WT) at birth and develop a slowly progressing demyelinating neuropathy. The aim of this study was to investigate whether the regeneration capacity of early symptomatic P0+/- is impaired as compared to age matched WT. Right sciatic nerves were lesioned at the thigh in 7-8 months old mice. Tibial motor axons at ankle were investigated by conventional motor conduction studies and axon excitability studies using threshold tracking. To evaluate regeneration we monitored the recovery of motor function after crush, and then compared the fiber distribution by histology. The overall motor performance was investigated using Rotor-Rod. P0+/- had reduced compound motor action potential amplitudes and thinner myelinated axons with only a borderline impairment in conduction and Rotor-Rod. Plantar muscle reinnervation occurred within 21 days in all mice. Shortly after reinnervation the conduction of P0+/- regenerated axons was markedly slower than WT, however, this difference decayed with time. Nevertheless, after 1 month, regenerated P0+/- axons had longer strength-duration time constant, larger threshold changes during hyperpolarizing electrotonus and longer relative refractory period. Their performance at Rotor-Rod remained also markedly impaired. In contrast, the number and diameter distribution of regenerating myelinated fibers became similar to regenerated WT. Our data suggest that in the presence of heterozygously P0 deficient Schwann cells, regenerating motor axons retain their ability to reinnervate their targets and remyelinate, though their functional recovery is delayed.
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Abstract
Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of inherited peripheral neuropathies in which the neuropathy is the sole or primary component of the disorder, as opposed to diseases in which the neuropathy is part of a more generalized neurologic or multisystem syndrome. Because of the great genetic heterogeneity of this condition, it can be challenging for the general neurologist to diagnose patients with specific types of CMT. This article reviews the biology of the inherited peripheral neuropathies, delineates major phenotypic features of the CMT subtypes, and suggest strategies for focusing genetic testing.
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Affiliation(s)
- Mario A Saporta
- National Laboratory of Embryonic Stem Cells, Biomedical Sciences Department, Federal University of Rio de Janeiro, Rua Republica do Peru 362/602, Rio de Janeiro 22021-040, Brazil.
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Schreiber S, Oldag A, Kornblum C, Kollewe K, Kropf S, Schoenfeld A, Feistner H, Jakubiczka S, Kunz WS, Scherlach C, Tempelmann C, Mawrin C, Dengler R, Schreiber F, Goertler M, Vielhaber S. Sonography of the median nerve in CMT1A, CMT2A, CMTX, and HNPP. Muscle Nerve 2013; 47:385-95. [PMID: 23381770 DOI: 10.1002/mus.23681] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2012] [Indexed: 02/06/2023]
Abstract
INTRODUCTION In this study we compare the ultrasound features in the median nerve in patients with different types of Charcot-Marie-Tooth (CMT) disease and hereditary neuropathies with liability to pressure palsies (HNPP) as a typical entrapment neuropathy. METHODS Median nerve ultrasound and conduction studies were performed in patients with CMT1A (n = 12), MFN2-associated CMT2A (n = 7), CMTX (n = 5), and HNPP (n = 5), and in controls (n = 28). RESULTS Median nerve cross-sectional area (CSA) was significantly increased in CMT1A, whereas, in axonal CMT2A, fascicle diameter (FD) was enlarged. CSA correlated with nerve conduction slowing in CMT1A and with axonal loss, as shown by motor and sensory nerve amplitudes in both CMT1A and CMT2A. A relatively low wrist-to-forearm-ratio (WFR <0.8) or a relatively high WFR (>1.8) appeared to be unlikely in MFN2 and Cx32 mutations of CMT2A and CMTX, respectively. CONCLUSION Differences in CSA, FD, and WFR of the median nerve can be helpful in defining subtypes of hereditary neuropathies.
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Affiliation(s)
- Stefanie Schreiber
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
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Pareyson D, Marchesi C, Salsano E. Dominant Charcot-Marie-Tooth syndrome and cognate disorders. HANDBOOK OF CLINICAL NEUROLOGY 2013; 115:817-845. [PMID: 23931817 DOI: 10.1016/b978-0-444-52902-2.00047-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Charcot-Marie-Tooth neuropathy (CMT) is a group of genetically heterogeneous disorders sharing a similar phenotype, characterized by wasting and weakness mainly involving the distal muscles of lower and upper limbs, variably associated with distal sensory loss and skeletal deformities. This chapter deals with dominantly transmitted CMT and related disorders, namely hereditary neuropathy with liability to pressure palsies (HNPP) and hereditary neuralgic amyotrophy (HNA). During the last 20 years, several genes have been uncovered associated with CMT and our understanding of the underlying molecular mechanisms has greatly improved. Consequently, a precise genetic diagnosis is now possible in the majority of cases, thus allowing proper genetic counseling. Although, unfortunately, treatment is still unavailable for all types of CMT, several cellular and animal models have been developed and some compounds have proved effective in these models. The first trials with ascorbic acid in CMT type 1A have been completed and, although negative, are providing relevant information on disease course and on how to prepare for future trials.
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Affiliation(s)
- Davide Pareyson
- Clinics of Central and Peripheral Degenerative Neuropathies Unit, Department of Clinical Neurosciences, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy.
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Jani-Acsadi A, Lewis RA. Evaluation of a patient with suspected chronic demyelinating polyneuropathy. HANDBOOK OF CLINICAL NEUROLOGY 2013; 115:253-64. [PMID: 23931785 DOI: 10.1016/b978-0-444-52902-2.00015-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- Agnes Jani-Acsadi
- Department of Neurology, University of Connecticut School of Medicine, Farmington, Connecticut, USA
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Crone C, Krarup C. Neurophysiological approach to disorders of peripheral nerve. HANDBOOK OF CLINICAL NEUROLOGY 2013; 115:81-114. [PMID: 23931776 DOI: 10.1016/b978-0-444-52902-2.00006-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological methods including nerve conduction studies and electromyography used in the study of patients suspected of having a neuropathy and the significance of the findings are discussed in detail and more novel and experimental methods are mentioned. Diagnostic considerations are based on a flow chart classifying neuropathies into eight categories based on mode of onset, distribution, and electrophysiological findings, and the electrophysiological characteristics in each type of neuropathy are discussed.
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Affiliation(s)
- Clarissa Crone
- Department of Clinical Neurophysiology, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
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Iguchi M, Hashiguchi A, Ito E, Toda K, Urano M, Shimizu Y, Takeuchi C, Saito K, Takashima H, Uchiyama S. Charcot-marie-tooth disease type 4C in Japan: Report of a case. Muscle Nerve 2012; 47:283-6. [DOI: 10.1002/mus.23540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2012] [Indexed: 11/07/2022]
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Li J, Parker B, Martyn C, Natarajan C, Guo J. The PMP22 gene and its related diseases. Mol Neurobiol 2012; 47:673-98. [PMID: 23224996 DOI: 10.1007/s12035-012-8370-x] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
Peripheral myelin protein-22 (PMP22) is primarily expressed in the compact myelin of the peripheral nervous system. Levels of PMP22 have to be tightly regulated since alterations of PMP22 levels by mutations of the PMP22 gene are responsible for >50 % of all patients with inherited peripheral neuropathies, including Charcot-Marie-Tooth type-1A (CMT1A) with trisomy of PMP22, hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of PMP22, and CMT1E with point mutations of PMP22. While overexpression and point-mutations of the PMP22 gene may produce gain-of-function phenotypes, deletion of PMP22 results in a loss-of-function phenotype that reveals the normal physiological functions of the PMP22 protein. In this article, we will review the basic genetics, biochemistry and molecular structure of PMP22, followed by discussion of the current understanding of pathogenic mechanisms involving in the inherited neuropathies with mutations in PMP22 gene.
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Affiliation(s)
- Jun Li
- VA Tennessee Valley Healthcare System, 1310 24th Avenue South, Nashville, TN 37212, USA.
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Abstract
With a prevalence of 1 in 2500 people, inherited peripheral nerve diseases, collectively called Charcot-Marie-Tooth disease (CMT), are among the most common inherited neurologic disorders. Patients with CMT typically present with chronic muscle weakness and atrophy in limbs, sensory loss in the feet and hands, and foot deformities. Clinical similarities between patients often require genetic testing to achieve a precise diagnosis. In this article, the author reviews the clinical and pathologic features of CMT, and demonstrates how electrodiagnostic and genetic tools are used to assist in the diagnosis and symptomatic management of the diseases. Several cases are presented to illustrate the diagnostic processes.
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Affiliation(s)
- Jun Li
- Department of Neurology, Center for Molecular Neuroscience, Center for Human Genetics Research, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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Kim YH, Chung HK, Park KD, Choi KG, Kim SM, Sunwoo IN, Choi YC, Lim JG, Lee KW, Kim KK, Lee DK, Joo IS, Kwon KH, Gwon SB, Park JH, Kim DS, Kim SH, Kim WK, Suh BC, Kim SB, Kim NH, Sohn EH, Kim OJ, Kim HS, Cho JH, Kang SY, Park CI, Oh J, Shin JH, Chung KW, Choi BO. Comparison between clinical disabilities and electrophysiological values in Charcot-Marie-Tooth 1A patients with PMP22 duplication. J Clin Neurol 2012; 8:139-45. [PMID: 22787498 PMCID: PMC3391619 DOI: 10.3988/jcn.2012.8.2.139] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 11/15/2011] [Accepted: 11/15/2011] [Indexed: 11/17/2022] Open
Abstract
Background and Purpose Charcot-Marie-Tooth disease (CMT) type 1A (CMT1A) is the demyelinating form of CMT that is significantly associated with PMP22 duplication. Some studies have found that the disease-related disabilities of these patients are correlated with their compound muscle action potentials (CMAPs), while others have suggested that they are related to the nerve conduction velocities. In the present study, we investigated the correlations between the disease-related disabilities and the electrophysiological values in a large cohort of Korean CMT1A patients. Methods We analyzed 167 CMT1A patients of Korean origin with PMP22 duplication using clinical and electrophysiological assessments, including the CMT neuropathy score and the functional disability scale. Results Clinical motor disabilities were significantly correlated with the CMAPs but not the motor nerve conduction velocities (MNCVs). Moreover, the observed sensory impairments matched the corresponding reductions in the sensory nerve action potentials (SNAPs) but not with slowing of the sensory nerve conduction velocities (SNCVs). In addition, CMAPs were strongly correlated with the disease duration but not with the age at onset. The terminal latency index did not differ between CMT1A patients and healthy controls. Conclusions In CMT1A patients, disease-related disabilities such as muscle wasting and sensory impairment were strongly correlated with CMAPs and SNAPs but not with the MNCVs or SNCVs. Therefore, we suggest that the clinical disabilities of CMT patients are determined by the extent of axonal dysfunction.
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Affiliation(s)
- Young Hwa Kim
- Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea
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Nerve conduction and electromyography studies. J Neurol 2012; 259:1502-8. [DOI: 10.1007/s00415-012-6497-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 03/22/2012] [Accepted: 03/23/2012] [Indexed: 12/14/2022]
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Charcot–Marie–Tooth diseases. Neurogenetics 2012. [DOI: 10.1017/cbo9781139087711.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Lourenço CM, Dupré N, Rivière JB, Rouleau GA, Marques VD, Genari AB, Santos AC, Barreira AA, Marques W. Expanding the differential diagnosis of inherited neuropathies with non-uniform conduction: Andermann syndrome. J Peripher Nerv Syst 2012; 17:123-7. [DOI: 10.1111/j.1529-8027.2012.00374.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Cassereau J, Chevrollier A, Bonneau D, Verny C, Procaccio V, Reynier P, Ferré M. A locus-specific database for mutations in GDAP1 allows analysis of genotype-phenotype correlations in Charcot-Marie-Tooth diseases type 4A and 2K. Orphanet J Rare Dis 2011; 6:87. [PMID: 22200116 PMCID: PMC3313893 DOI: 10.1186/1750-1172-6-87] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 12/26/2011] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND The ganglioside-induced differentiation-associated protein 1 gene (GDAP1), which is involved in the Charcot-Marie-Tooth disease (CMT), the most commonly inherited peripheral neuropathy, encodes a protein anchored to the mitochondrial outer membrane. The phenotypic presentations of patients carrying GDAP1 mutations are heterogeneous, making it difficult to determine genotype-phenotype correlations, since the majority of the mutations have been found in only a few unrelated patients. Locus-specific databases (LSDB) established in the framework of the Human Variome Project provide powerful tools for the investigation of such rare diseases. METHODS AND RESULTS We report the development of a publicly accessible LSDB for the GDAP1 gene. The GDAP1 LSDB has adopted the Leiden Open-source Variation Database (LOVD) software platform. This database, which now contains 57 unique variants reported in 179 cases of CMT, offers a detailed description of the molecular, clinical and electrophysiological data of the patients. The usefulness of the GDAP1 database is illustrated by the finding that GDAP1 mutations lead to primary axonal damage in CMT, with secondary demyelination in the more severe cases of the disease. CONCLUSION Findings of this nature should lead to a better understanding of the pathophysiology of CMT. Finally, the GDAP1 LSDB, which is part of the mitodyn.org portal of databases of genes incriminated in disorders involving mitochondrial dynamics and bioenergetics, should yield new insights into mitochondrial diseases.
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Saporta ASD, Sottile SL, Miller LJ, Feely SME, Siskind CE, Shy ME. Charcot-Marie-Tooth disease subtypes and genetic testing strategies. Ann Neurol 2011; 69:22-33. [PMID: 21280073 DOI: 10.1002/ana.22166] [Citation(s) in RCA: 364] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Charcot-Marie-Tooth disease (CMT) affects 1 in 2,500 people and is caused by mutations in more than 30 genes. Identifying the genetic cause of CMT is often necessary for family planning, natural history studies, and for entry into clinical trials. However genetic testing can be both expensive and confusing to patients and physicians. METHODS We analyzed data from 1,024 of our patients to determine the percentage and features of each CMT subtype within this clinic population. We identified distinguishing clinical and physiological features of the subtypes that could be used to direct genetic testing for patients with CMT. RESULTS Of 1,024 patients evaluated, 787 received CMT diagnoses. A total of 527 patients with CMT (67%) received a genetic subtype, while 260 did not have a mutation identified. The most common CMT subtypes were CMT1A, CMT1X, hereditary neuropathy with liability to pressure palsies (HNPP), CMT1B, and CMT2A. All other subtypes accounted for less than 1% each. Eleven patients had >1 genetically identified subtype of CMT. Patients with genetically identified CMT were separable into specific groups based on age of onset and the degree of slowing of motor nerve conduction velocities. INTERPRETATION Combining features of the phenotypic and physiology groups allowed us to identify patients who were highly likely to have specific subtypes of CMT. Based on these results, we propose a strategy of focused genetic testing for CMT, illustrated in a series of flow diagrams created as testing guides.
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Deymeer F, Matur Z, Poyraz M, Battaloglu E, Oflazer-Serdaroglu P, Parman Y. Nerve conduction studies in Charcot-Marie-Tooth disease in a cohort from Turkey. Muscle Nerve 2011; 43:657-64. [DOI: 10.1002/mus.21932] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2010] [Indexed: 11/09/2022]
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Murphy SM, Polke J, Manji H, Blake J, Reiniger L, Sweeney M, Houlden H, Brandner S, Reilly MM. A novel mutation in the nerve-specific 5'UTR of the GJB1 gene causes X-linked Charcot-Marie-Tooth disease. J Peripher Nerv Syst 2011; 16:65-70. [PMID: 21504505 DOI: 10.1111/j.1529-8027.2011.00321.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
X-linked Charcot-Marie-Tooth disease (CMT1X) is the second most common cause of CMT, and is usually caused by mutations in the gap junction protein beta 1 (GJB1) gene which codes for connexin 32 (CX32). CX32 has three tissue-specific promoters, P1 which is specific for liver and pancreas, P1a specific for liver, oocytes and embryonic stem cells, and P2 which is nerve-specific. Over 300 mutations have been described in GJB1, spread throughout the coding region. We describe two families with X-linked inheritance and a phenotype consistent with CMT1X who did not have mutations in the GJB1 coding region. The non-coding region of GJB1 was sequenced and an upstream exon-splicing variant found at approximately - 373G>A which segregated with the disease in both families and was not present in controls. This substitution is located at the last base of the nerve-specific 5'UTR and thus may disrupt splicing of the nerve-specific transcript. Online consensus splice-site programs predict a reduced score for the mutant sequence vs. the normal sequence. It is likely that other mutations within the GJB1 non-coding regions account for the CMT1X families who do not have coding region mutations.
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Affiliation(s)
- Sinéad M Murphy
- MRC Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK.
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Cassereau J, Chevrollier A, Gueguen N, Desquiret V, Verny C, Nicolas G, Dubas F, Amati-Bonneau P, Reynier P, Bonneau D, Procaccio V. Mitochondrial dysfunction and pathophysiology of Charcot–Marie–Tooth disease involving GDAP1 mutations. Exp Neurol 2011; 227:31-41. [DOI: 10.1016/j.expneurol.2010.09.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/02/2010] [Accepted: 09/04/2010] [Indexed: 11/29/2022]
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Moldovan M, Alvarez S, Pinchenko V, Klein D, Nielsen FC, Wood JN, Martini R, Krarup C. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons. ACTA ACUST UNITED AC 2010; 134:585-601. [PMID: 21169333 DOI: 10.1093/brain/awq336] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies with conventional nerve conduction studies, behavioural studies using rotor-rod measurements, and histological measures to assess membrane dysfunction and its progression in protein zero deficient homozygous mutants as compared with age-matched wild-type controls. The involvement of Na(V)1.8 was investigated by pharmacologic block using the subtype-selective Na(V)1.8 blocker A-803467 and chronically in Na(V)1.8 knock-outs. We found that in the context of dysmyelination, abnormal potassium ion currents and membrane depolarization, the ectopic Na(V)1.8 channels further impair the motor axon excitability in protein zero deficient homozygous mutants to an extent that precipitates conduction failure in severely affected axons. Our data suggest that a Na(V)1.8 channelopathy contributed to the poor motor function of protein zero deficient homozygous mutants, and that the conduction failure was associated with partially reversible reduction of the electrically evoked muscle response and of the clinical function as indicated by the partial recovery of function at rotor-rod measurements. As a consequence of these findings of partially reversible dysfunction, we propose that the Na(V)1.8 voltage gated sodium channel should be considered as a novel therapeutic target for Charcot-Marie-Tooth disease.
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Affiliation(s)
- Mihai Moldovan
- Institute of Neuroscience and Pharmacology, Panum, University of Copenhagen, Denmark
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Marques W, Funayama CAR, Secchin JB, Lourenço CM, Gouvêa SP, Marques VD, Bastos PG, Barreira AA. Coexistence of two chronic neuropathies in a young child: Charcot-marie-tooth disease type 1A and chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2010; 42:598-600. [DOI: 10.1002/mus.21753] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Investigations and treatment of chronic inflammatory demyelinating polyradiculoneuropathy and other inflammatory demyelinating polyneuropathies. Curr Opin Neurol 2010; 23:242-8. [DOI: 10.1097/wco.0b013e3283394203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Reilly MM. Classification and diagnosis of the inherited neuropathies. Ann Indian Acad Neurol 2010; 12:80-8. [PMID: 20142852 PMCID: PMC2812746 DOI: 10.4103/0972-2327.53075] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Accepted: 03/20/2009] [Indexed: 11/25/2022] Open
Affiliation(s)
- Mary M Reilly
- Department of Molecular Neurosciences, MRC Centre for Neuromuscular Disease, National Hospital for Neurology and Neurosurgery and Institute of Neurology, Queen Square, London WC1N 3BG, UK
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Abstract
Patients with PMP22 deficiency present with focal sensory and motor deficits when peripheral nerves are stressed by mechanical force. It has been hypothesized that these focal deficits are due to mechanically induced conduction block (CB). To test this hypothesis, we induced 60-70% CB (defined by electrophysiological criteria) by nerve compression in an authentic mouse model of hereditary neuropathy with liability to pressure palsies (HNPP) with an inactivation of one of the two pmp22 alleles (pmp22(+/-)). Induction time for the CB was significantly shorter in pmp22(+/-) mice than that in pmp22(+/+) mice. This shortened induction was also found in myelin-associated glycoprotein knock-out mice, but not in the mice with deficiency of myelin protein zero, a major structural protein of compact myelin. Pmp22(+/-) nerves showed intact tomacula with no segmental demyelination in both noncompressed and compressed conditions, normal molecular architecture, and normal concentration of voltage-gated sodium channels by [(3)H]-saxitoxin binding assay. However, focal constrictions were observed in the axonal segments enclosed by tomacula, a pathological hallmark of HNPP. The constricted axons increase axial resistance to action potential propagation, which may hasten the induction of CB in Pmp22 deficiency. Together, these results demonstrate that a function of Pmp22 is to protect the nerve from mechanical injury.
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Scelsa SN. Familial, demyelinating sensory and motor polyneuropathy with conduction block. Muscle Nerve 2009; 41:558-62. [DOI: 10.1002/mus.21558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pareyson D, Marchesi C. Diagnosis, natural history, and management of Charcot–Marie–Tooth disease. Lancet Neurol 2009; 8:654-67. [PMID: 19539237 DOI: 10.1016/s1474-4422(09)70110-3] [Citation(s) in RCA: 377] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Congenital hypomyelinating neuropathy with lethal conduction failure in mice carrying the Egr2 I268N mutation. J Neurosci 2009; 29:2312-21. [PMID: 19244508 DOI: 10.1523/jneurosci.2168-08.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mouse models of human disease are helpful for understanding the pathogenesis of the disorder and ultimately for testing potential therapeutic agents. Here, we describe the engineering and characterization of a mouse carrying the I268N mutation in Egr2, observed in patients with recessively inherited Charcot-Marie-Tooth (CMT) disease type 4E, which is predicted to alter the ability of Egr2 to interact with the Nab transcriptional coregulatory proteins. Mice homozygous for Egr2(I268N) develop a congenital hypomyelinating neuropathy similar to their human counterparts. Egr2(I268N) is expressed at normal levels in developing nerve but is unable to interact with Nab proteins or to properly activate transcription of target genes critical for proper peripheral myelin development. Interestingly, Egr2(I268N/I268N) mutant mice maintain normal weight and have only mild tremor until 2 weeks after birth, at which point they rapidly develop worsening weakness and uniformly die within several days. Nerve electrophysiology revealed conduction block, and neuromuscular junctions showed marked terminal sprouting similar to that seen in animals with pharmacologically induced blockade of action potentials or neuromuscular transmission. These studies describe a unique animal model of CMT, whereby weakness is due to conduction block or neuromuscular junction failure rather than secondary axon loss and demonstrate that the Egr2-Nab complex is critical for proper peripheral nerve myelination.
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Vanhaesebrouck AE, Couturier J, Cauzinille L, Mizisin AP, Shelton GD, Granger N. Demyelinating polyneuropathy with focally folded myelin sheaths in a family of Miniature Schnauzer dogs. J Neurol Sci 2008; 275:100-5. [PMID: 18809183 DOI: 10.1016/j.jns.2008.07.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 07/27/2008] [Accepted: 07/31/2008] [Indexed: 01/08/2023]
Abstract
A spontaneous demyelinating polyneuropathy in two young Miniature Schnauzer dogs was characterized clinically, electrophysiologically and histopathologically. Both dogs were related and a third dog, belonging to the same family, had similar clinical signs. On presentation, clinical signs were restricted to respiratory dysfunction. Electrophysiological tests showed a dramatic decrease in both motor and sensory nerve conduction velocities. Microscopic examination of peripheral nerve biopsies (light and electron microscopy, teased nerve fibers), showed that this neuropathy was characterized by segmental demyelination and focally folded myelin sheaths. Various clinical syndromes associated with tomacula or focal thickening of the myelin sheath of the peripheral nerves have been described in humans and shown to be caused by gene mutations affecting the myelin proteins, such as the hereditary neuropathy with liability to pressure palsies or the demyelinating forms of Charcot-Marie-Tooth disease. In animals, a tomaculous neuropathy has been reported in cattle and chickens but not in carnivores. Here we report a demyelinating peripheral neuropathy with tomacula in two Miniature Schnauzer dogs.
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