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Harrison P, Barton J, Winkel A. Chronic mimics of myasthenia gravis: a retrospective case series. Neuromuscul Disord 2023; 33:250-256. [PMID: 36753801 DOI: 10.1016/j.nmd.2023.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 01/29/2023]
Abstract
Myasthenia gravis often presents a diagnostic challenge and may be misdiagnosed, particularly in seronegative disease with active symptoms. We retrospectively evaluated 61 patients following the introduction of single fibre electromyography at our service, and identified 8 mimics which had been inappropriately diagnosed and treated as refractory myasthenia gravis. 6 of these were seronegative, but two had positive acetylcholine receptor (AChR) antibodies. The final diagnoses included one case each of chronic progressive external ophthalmoplegia, chronic ptosis, oculopharyngeal muscular dystrophy, and an undifferentiated disorder suspicious for either a mitochondrial cytopathy or low-grade myositis. Four were diagnosed with functional neurological disorder, one of which had a superimposed thyroid myopathy and orbitopathy. We found the average duration of misdiagnosis was 9 years (SD±5.2, median 11 years), and patients were often exposed to years of unnecessary treatment. All patients had received anticholinesterase therapy, three had immunotherapy, and three surgical interventions were performed including two thymectomies. We found myasthenic mimics should be suspected in disease that is static and treatment refractory, and functional mimics in disease with frequent flares. Thorough neurophysiologic assessment is important, particularly when making a diagnosis of seronegative myasthenia gravis.
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Affiliation(s)
- Patrick Harrison
- Neurology Department, Sunshine Coast University Hospital, 6 Doherty St, Birtinya Qld 4575, Australia; Griffith University, School of Medicine, Australia.
| | - Joshua Barton
- Neurology Department, Sunshine Coast University Hospital, 6 Doherty St, Birtinya Qld 4575, Australia
| | - Antony Winkel
- Neurology Department, Sunshine Coast University Hospital, 6 Doherty St, Birtinya Qld 4575, Australia; Griffith University, School of Medicine, Australia
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2
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Abstract
Progressive external ophthalmoplegia (PEO), characterized by ptosis and impaired eye movements, is a clinical syndrome with an expanding number of etiologically distinct subtypes. Advances in molecular genetics have revealed numerous pathogenic causes of PEO, originally heralded in 1988 by the detection of single large-scale deletions of mitochondrial DNA (mtDNA) in skeletal muscle of people with PEO and Kearns-Sayre syndrome. Since then, multiple point variants of mtDNA and nuclear genes have been identified to cause mitochondrial PEO and PEO-plus syndromes, including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and sensory ataxic neuropathy dysarthria ophthalmoplegia (SANDO). Intriguingly, many of those nuclear DNA pathogenic variants impair maintenance of the mitochondrial genome causing downstream mtDNA multiple deletions and depletion. In addition, numerous genetic causes of nonmitochondrial PEO have been identified.
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Affiliation(s)
- Michio Hirano
- H. Houston Merritt Neuromuscular Research Center, Neuromuscular Medicine Division, Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States.
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, United Kingdom
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3
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Jordan DR, Klapper SR, Farmer J. Oculopharyngeal Muscular Dystrophy Ptosis, Mueller's Muscle Involvement, and a Review of Management Over 34 Years. Ophthalmic Plast Reconstr Surg 2022; 38:535-542. [PMID: 35030153 DOI: 10.1097/iop.0000000000002118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To review the management of the ptosis associated with oculopharyngeal muscular dystrophy (OPMD) from one author's experience over 34 years, demonstrate Mueller's muscle involvement in this disease, and how this impacts the preferred choice of surgery. METHODS Retrospective, nonrandomized comparative case series. Forty patients with OPMD who underwent primary bilateral ptosis surgery through an anterior eyelid incision and had their Mueller's muscle biopsied (one side) and sent for histopathologic analysis were selected for chart review. The main outcome measure was the presence or absence of dystrophic changes in the biopsied Mueller's muscle. RESULTS In 29/40 biopsies (72.5%), there were dystrophic changes and fatty infiltration of Mueller's muscle identified histopathologically. CONCLUSIONS Mueller's muscle is involved in the dystrophic process more often than expected contributing to ptosis in the OPMD syndrome. A combined Mueller's-aponeurotic advancement is more effective at elevating the eyelid than simply advancing the aponeurosis when Mueller's is fatty infiltrated at the time of external levator advancement surgery in our experience. Management strategies for ptosis surgery in OPMD are reviewed. The age of onset, levator muscle function, previous ptosis repair, how debilitated the patient is with their disease process systemically, as well as the presence of other eye problems (e.g., dry eye, prior glaucoma filtering procedures, history of corneal surgery, laser refractive procedure) are important clinical considerations in patients with OPMD.
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Affiliation(s)
- David R Jordan
- Department of Ophthalmology, The Ottawa Hospital General Campus, Ottawa, Ontario, Canada
| | - Stephen R Klapper
- Department of Ophthalmology, Indiana University School of medicine, Indianapolis, Indiana, U.S.A
| | - James Farmer
- Department of Pathology, The Ottawa Hospital General Campus, Ottawa, Ontario, Canada
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4
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Versluys L, Ervilha Pereira P, Schuermans N, De Paepe B, De Bleecker JL, Bogaert E, Dermaut B. Expanding the TDP-43 Proteinopathy Pathway From Neurons to Muscle: Physiological and Pathophysiological Functions. Front Neurosci 2022; 16:815765. [PMID: 35185458 PMCID: PMC8851062 DOI: 10.3389/fnins.2022.815765] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 01/02/2023] Open
Abstract
TAR DNA-binding protein 43, mostly referred to as TDP-43 (encoded by the TARDBP gene) is strongly linked to the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). From the identification of TDP-43 positive aggregates in the brains and spinal cords of ALS/FTD patients, to a genetic link between TARBDP mutations and the development of TDP-43 pathology in ALS, there is strong evidence indicating that TDP-43 plays a pivotal role in the process of neuronal degeneration. What this role is, however, remains to be determined with evidence ranging from gain of toxic properties through the formation of cytotoxic aggregates, to an inability to perform its normal functions due to nuclear depletion. To add to an already complex subject, recent studies highlight a role for TDP-43 in muscle physiology and disease. We here review the biophysical, biochemical, cellular and tissue-specific properties of TDP-43 in the context of neurodegeneration and have a look at the nascent stream of evidence that positions TDP-43 in a myogenic context. By integrating the neurogenic and myogenic pathological roles of TDP-43 we provide a more comprehensive and encompassing view of the role and mechanisms associated with TDP-43 across the various cell types of the motor system, all the way from brain to limbs.
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Affiliation(s)
- Lauren Versluys
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Pedro Ervilha Pereira
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Nika Schuermans
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Boel De Paepe
- Department of Neurology and Neuromuscular Reference Center, Ghent University Hospital, Ghent, Belgium
- Department of Head and Skin, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jan L. De Bleecker
- Department of Neurology and Neuromuscular Reference Center, Ghent University Hospital, Ghent, Belgium
- Department of Head and Skin, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Elke Bogaert
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Bart Dermaut
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
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5
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Bermejo-Guerrero L, de Fuenmayor-Fernández de la Hoz CP, Serrano-Lorenzo P, Blázquez-Encinar A, Gutiérrez-Gutiérrez G, Martínez-Vicente L, Galán-Dávila L, García-García J, Arenas J, Muelas N, Hernández-Laín A, Domínguez-González C, Martín MA. Clinical, Histological, and Genetic Features of 25 Patients with Autosomal Dominant Progressive External Ophthalmoplegia (ad-PEO)/PEO-Plus Due to TWNK Mutations. J Clin Med 2021; 11:jcm11010022. [PMID: 35011763 PMCID: PMC8745442 DOI: 10.3390/jcm11010022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 11/28/2022] Open
Abstract
Autosomal dominant mutations in the TWNK gene, which encodes a mitochondrial DNA helicase, cause adult-onset progressive external ophthalmoplegia (PEO) and PEO-plus presentations. In this retrospective observational study, we describe clinical and complementary data from 25 PEO patients with mutations in TWNK recruited from the Hospital 12 de Octubre Mitochondrial Disorders Laboratory Database. The mean ages of onset and diagnosis were 43 and 63 years, respectively. Family history was positive in 22 patients. Ptosis and PEO (92% and 80%) were the most common findings. Weakness was present in 48%, affecting proximal limbs, neck, and bulbar muscles. Exercise intolerance was present in 28%. Less frequent manifestations were cardiac (24%) and respiratory (4%) involvement, neuropathy (8%), ataxia (4%), and parkinsonism (4%). Only 28% had mild hyperCKemia. All 19 available muscle biopsies showed signs of mitochondrial dysfunction. Ten different TWNK mutations were identified, with c.1361T>G (p.Val454Gly) and c.1070G>C (p.Arg357Pro) being the most common. Before definitive genetic confirmation, 56% of patients were misdiagnosed (36% with myasthenia, 20% with oculopharyngeal muscle dystrophy). Accurate differential diagnosis and early confirmation with appropriately chosen complementary studies allow genetic counseling and the avoidance of unnecessary treatments. Thus, mitochondrial myopathies must be considered in PEO/PEO-plus presentations, and particularly, TWNK is an important cause when positive family history is present.
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Affiliation(s)
- Laura Bermejo-Guerrero
- Neuromuscular Unit, Department of Neurology, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain; (L.B.-G.); (C.P.d.F.-F.d.l.H.)
| | | | - Pablo Serrano-Lorenzo
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Mitochondrial Disorders Laboratory, Clinical Biochemistry Department, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Alberto Blázquez-Encinar
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Mitochondrial Disorders Laboratory, Clinical Biochemistry Department, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | | | - Laura Martínez-Vicente
- Department of Neurology, Hospital Universitario Clínico San Carlos, 28040 Madrid, Spain; (L.M.-V.); (L.G.-D.)
| | - Lucía Galán-Dávila
- Department of Neurology, Hospital Universitario Clínico San Carlos, 28040 Madrid, Spain; (L.M.-V.); (L.G.-D.)
| | - Jorge García-García
- Department of Neurology, Complejo Hospitalario Universitario de Albacete, 02006 Albacete, Spain;
| | - Joaquín Arenas
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Mitochondrial Disorders Laboratory, Clinical Biochemistry Department, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Nuria Muelas
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Neuromuscular Unit, Department of Neurology, Hospital Universitari I Politècnic La Fe, 46026 Valencia, Spain
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, 46026 Valencia, Spain
| | - Aurelio Hernández-Laín
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Department of Neuropathology, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Cristina Domínguez-González
- Neuromuscular Unit, Department of Neurology, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain; (L.B.-G.); (C.P.d.F.-F.d.l.H.)
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Correspondence:
| | - Miguel A. Martín
- Hospital 12 de Octubre Research Institute (imas12), 28041 Madrid, Spain; (P.S.-L.); (A.B.-E.); (J.A.); (A.H.-L.); (M.A.M.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Mitochondrial Disorders Laboratory, Clinical Biochemistry Department, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
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Papadopoulos C, Papadimas GK. The Relevance of Blepharoptosis in Diagnostic Suspicion of Myopathies. Neurol India 2021; 69:177-180. [PMID: 33642296 DOI: 10.4103/0028-3886.310067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Blepharoptosis (ptosis) is classified, based on etiology, into mechanical, cerebral, neurogenic, neuromuscular, myogenic, and due to miscellaneous causes. Primary myopathic diseases are rare causes of blepharoptosis and many patients with myogenic ptosis undergo a series of extensive investigations before a myopathy is being considered. In this study, we report four patients with different myopathic disorders who had blepharoptosis as a presenting symptom of their disease. Moreover, we highlight frequent diagnostic errors and difficulties in patients with myopathies who present blepharoptosis. Lack of clear cut aggravation of symptoms by fatigue and response to cholinesterase inhibitors treatment, the association of proximal, distal or extraocular muscle weakness, and positive family history or evidence of a multi systemic disorder should prompt evaluation of an underlying myopathy.
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Affiliation(s)
| | - George K Papadimas
- Department of Neurology, Aegintion Hospital, Medical School of Athens, Greece
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7
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Wong A, Garcia SM, Tamaki S, Striedinger K, Barruet E, Hansen SL, Young DM, Pomerantz JH. Satellite cell activation and retention of muscle regenerative potential after long-term denervation. Stem Cells 2021; 39:331-344. [PMID: 33326654 DOI: 10.1002/stem.3316] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022]
Abstract
Irreversible denervation atrophy remains an unsolved clinical problem, and the role of skeletal muscle stem cell (MuSC, satellite cell) depletion in this process is unclear. We investigated the ability of MuSCs to regenerate muscle in the context of denervation. Three to 12 months following sciatic denervation in mice, MuSC number, size, EdU uptake, rate of division, and mitochondrial activity were increased. Following acute myotoxin injury, denervated muscles formed new muscle fibers in situ. MuSCs isolated via flow cytometry from denervated mouse muscle, or from atrophic denervated gluteus maximus muscles of humans with complete spinal cord injuries two decades prior, formed new muscle fibers and reoccupied the anatomic niche after transplantation into uninjured muscle. Our results show unequivocally that, even after prolonged denervation, MuSCs retain intrinsic regenerative potential similar to that of uninjured MuSCs. Treatment of denervation atrophy will require elucidating the non-MuSC environmental changes in muscle that prevent functional regeneration.
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Affiliation(s)
- Alvin Wong
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Steven M Garcia
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Stanley Tamaki
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Katharine Striedinger
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Emilie Barruet
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Scott L Hansen
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - David M Young
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
| | - Jason H Pomerantz
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Program in Craniofacial Biology, Eli and Edythe Broad Center of Regeneration Medicine, University of California, San Francisco, California, USA
- Department of Orofacial Sciences, University of California, San Francisco, California, USA
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8
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Oculopharyngeal Muscular Dystrophy, an Often Misdiagnosed Neuromuscular Disorder: A Southern California Experience. J Clin Neuromuscul Dis 2020; 21:61-68. [PMID: 31743248 DOI: 10.1097/cnd.0000000000000271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Oculopharyngeal muscular dystrophy (OPMD) is a rare neuromuscular disorder characterized by late-onset development of bilateral eyelid ptosis, ophthalmoparesis and dysphagia with further progression to proximal limb muscle weakness that is an under recognized condition. The mode of inheritance is usually autosomal dominant, but a recessive form has been reported. OPMD is caused by a short expansion of the alanine repeat (GCN trinucleotide) in the poly(adenylate)-binding protein nuclear1 (PABPN1) gene. METHODS We performed a retrospective review of undiagnosed cases that initially presented with ptosis, diplopia, dysphagia, muscle weakness, muscular dystrophy and/or myasthenia gravis from 2000 to 2015 at two institutions in Southern California. RESULTS Twenty-five patients were identified to have OPMD with genetic confirmation. CONCLUSIONS Even though a rare condition, the prevalence is disproportionally frequent in certain ethnic groups and in certain regions; thus, we report our experience of OPMD patients in Southern California.
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9
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The Role of Muscle Stem Cells in Regeneration and Recovery after Denervation: A Review. Plast Reconstr Surg 2019; 143:779-788. [PMID: 30817650 DOI: 10.1097/prs.0000000000005370] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Skeletal muscle denervation is a complex clinical problem that still lacks a comprehensive solution. Previous studies have suggested that prolonged periods of denervation lead to a decline in the muscle stem cell population, negatively affecting the ability of muscle to regenerate following reinnervation. Recent advances in the understanding of muscle stem cell biology, along with new techniques that increase the ability to identify and manipulate these cells, provide an opportunity to definitively address the impact of muscle stem cells in recovery from denervation and their potential role in treatment. METHODS A comprehensive review of the literature on the biology of muscle denervation, and the effect of denervation injury on muscle stem cell behavior, was performed. RESULTS In this review, the authors discuss the current understanding of muscle stem cell biology in the setting of denervation atrophy, review barriers to successful reinnervation, and review options available to patients following denervation injury. The authors also discuss potential use of muscle stem cells in future therapies. CONCLUSIONS Although the clinical treatment of prolonged denervation injury has improved in recent years, regeneration of native muscle remains elusive. Muscle stem cells have been demonstrated to be of central importance in muscle regeneration following injury, and may be a powerful tool that provides effective new options for future treatments. Additional work clarifying the effect of denervation injury on satellite cells is needed to determine whether they are a limiting factor in recovery and to demonstrate whether their clinical use as a cell-based therapy in denervation injury can be efficacious.
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10
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Meira B, Roque R, Pinto M, Caetano A. Late-onset presentation of POLG1-associated mitochondrial disease. BMJ Case Rep 2019; 12:12/3/e228482. [PMID: 30936349 DOI: 10.1136/bcr-2018-228482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Mutations in the nuclear POLG1 gene compromise the integrity of mitochondrial DNA and show great allelic and clinical heterogeneity. Among adult POLG1-associated mitochondrial disease, the main clinical feature is chronic progressive external ophthalmoplegia. Other related clinical manifestations are sensory or cerebellar ataxia, peripheral neuropathy, myopathy or extrapyramidal symptoms. We report the case of a 72-year-old man who presented with a late onset sensory neuronopathy, chronic progressive external ophthalmoplegia, gait ataxia and parkinsonism. Genetic studies showed a compound heterozygosity of known pathogenic mutations in the POLG1 gene (variant T252I/P587 L in cis configuration in allele 1 and variant R807C in allele 2). Late life presentation highlights that mitochondrial disorders should be considered regardless of age of onset of symptoms.
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Affiliation(s)
- Bruna Meira
- Neurology Department, Centro Hospitalar de Lisboa Ocidental EPE, Lisboa, Portugal
| | - Rafael Roque
- Neuropathology Unit - Neurology Department, Centro Hospitalar Lisboa Norte EPE, Lisboa, Portugal
| | - Miguel Pinto
- Neurology Department, Centro Hospitalar de Lisboa Ocidental EPE, Lisboa, Portugal
| | - André Caetano
- Neurology Department, Centro Hospitalar de Lisboa Ocidental EPE, Lisboa, Portugal
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11
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Waito AA, Steele CM, Peladeau-Pigeon M, Genge A, Argov Z. A Preliminary Videofluoroscopic Investigation of Swallowing Physiology and Function in Individuals with Oculopharyngeal Muscular Dystrophy (OPMD). Dysphagia 2018; 33:789-802. [PMID: 29725764 DOI: 10.1007/s00455-018-9904-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/24/2018] [Indexed: 12/13/2022]
Abstract
Dysphagia is one of the primary symptoms experienced by individuals with Oculopharyngeal Muscular Dystrophy (OPMD). However, we lack understanding of the discrete changes in swallowing physiology that are seen in OPMD, and the resulting relationship to impairments of swallowing safety and efficiency. This study sought to describe the pathophysiology of dysphagia in a small sample of patients with OPMD using a videofluoroscopy examination (VFSS) involving 3 × 5 mL boluses of thin liquid barium (22% w/v). The aim of this study is to extend what is known about the pathophysiology of dysphagia in OPMD, by quantifying changes in swallow timing, kinematics, safety, and efficiency, measured from VFSS. This study is a secondary analysis of baseline VFSS collected from 11 adults (4 male), aged 48-62 (mean 57) enrolled in an industry-sponsored phase 2 therapeutic drug trial. Blinded raters scored the VFSS recordings for safety [Penetration-Aspiration Scale (PAS)], efficiency [Normalized Residue Ratio Scale (NRRS)], timing [Pharyngeal Transit Time (PTT), Swallow Reaction Time (SRT), Laryngeal Vestibule Closure Reaction Time (LVCrt), Upper Esophageal Sphincter Opening Duration (UESD)], and kinematics (hyoid movement, pharyngeal constriction, UES opening width). Impairment thresholds from existing literature were defined to characterize swallowing physiology and function. Further, Fisher's Exact tests and Pearson's correlations were used to conduct a preliminary exploration of associations between swallowing physiology (e.g., kinematics, timing) and function (i.e., safety, efficiency). Compared to published norms, we identified significant differences in the degree of maximum pharyngeal constriction, hyoid movement distance and speed, as well as degree and timeliness of airway closure. Unsafe swallowing (PAS ≥ 3) was seen in only 3/11 patients. By contrast, clinically significant residue (i.e., NRRS scores ≥ 0.09 vallecular; ≥ 0.2 pyriform) was seen in 7/11 patients. Fisher's Exact tests revealed associations between prolonged SRT, PTT, and unsafe swallowing. Weak associations were also identified between post-swallow residue and poor pharyngeal constriction during the swallow. Detailed analysis of swallowing physiology in this series of adults with OPMD aligns with impaired muscular function (e.g., reduced pharyngeal constriction, incomplete laryngeal vestibule closure) associated with the disease, and primary functional challenges with swallow efficiency. Further work is needed to explore a greater range of food and liquid textures, and to identify additional physiological mechanisms underlying swallowing impairment in OPMD.
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Affiliation(s)
- Ashley A Waito
- Swallowing Rehabilitation Research Laboratory, Toronto Rehabilitation Institute - University Health Network, 550 University Avenue, 12th Floor, Toronto, ON, M5G 2A2, Canada. .,Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada.
| | - Catriona M Steele
- Swallowing Rehabilitation Research Laboratory, Toronto Rehabilitation Institute - University Health Network, 550 University Avenue, 12th Floor, Toronto, ON, M5G 2A2, Canada.,Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada
| | - Melanie Peladeau-Pigeon
- Swallowing Rehabilitation Research Laboratory, Toronto Rehabilitation Institute - University Health Network, 550 University Avenue, 12th Floor, Toronto, ON, M5G 2A2, Canada
| | - Angela Genge
- Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
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12
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Youssof S, Romero-Clark C, Warner T, Plowman E. Dysphagia-related quality of life in oculopharyngeal muscular dystrophy: Psychometric properties of the SWAL-QOL instrument. Muscle Nerve 2017; 56:28-35. [PMID: 27759888 DOI: 10.1002/mus.25441] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The Swallowing Quality of Life instrument (SWAL-QOL) is a patient-reported outcome measure of swallowing-related quality of life (SR-QoL). Its psychometric properties in oculopharyngeal muscular dystrophy (OPMD) are not known. METHODS We administered the SWAL-QOL to U.S. OPMD Registry participants. We described SR-QoL profiles and assessed reliability and validity. RESULTS The mean composite score in 113 individuals with OPMD was 54.4 ± 20.7, indicating moderate impairment. Severe impairments were observed in eating duration, burden, and fatigue scales. Internal consistency reliability of all scales was found to be satisfactory, and 9 of 10 scales demonstrated adequate test-retest reliability. Data confirmed 86% of hypotheses, supporting construct validity. The SWAL-QOL limitations in OPMD include: floor/ceiling effects in 7 of 10 scales and low specificity of sleep, fatigue, and communication scales for dysphagia. CONCLUSIONS SR-QoL is reduced in OPMD. Given several limitations of the SWAL-QOL, development of an improved dysphagia-specific QoL instrument for OPMD is warranted. Muscle Nerve 56: 28-35, 2017.
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Affiliation(s)
- Sarah Youssof
- Department of Neurology, MSC 10 5620, 1, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
| | - Carol Romero-Clark
- Speech, Language, Swallow Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Teddy Warner
- Department of Family and Community Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Emily Plowman
- Speech, Language and Hearing Sciences, Center for Respiratory Research & Rehabilitation, University of Florida, Gainesville, Florida, USA
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Kidd DP. Case 5. Neuroophthalmology 2017. [DOI: 10.1007/978-1-4471-2410-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Cruz-Aguilar M, Guerrero-de Ferran C, Tovilla-Canales JL, Nava-Castañeda A, Zenteno JC. Characterization of PABPN1 expansion mutations in a large cohort of Mexican patients with oculopharyngeal muscular dystrophy (OPMD). J Investig Med 2016; 65:705-708. [PMID: 27980005 DOI: 10.1136/jim-2016-000184] [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] [Accepted: 11/26/2016] [Indexed: 11/03/2022]
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is an autosomal-dominant, adult-onset disorder defined by blepharoptosis, dysphagia, and proximal muscle weakness. OPMD arises from heterozygous expansions of a trinucleotide (GCN) tract situated at the 5' region of the polyadenylate RNA binding protein 1 (PABPN1) gene. The frequency of a particular (GCN) expansion in a given population of patients with OPMD is largely influenced by the occurrence of founder mutations. Analysis of large groups of patients with OPMD from different ethnic origins will help to estimate the relative contribution of each expanded allele to the disease. The purpose of this study was to characterize the type of PABPN1 expanded alleles in a large cohort of OPMD individuals from Mexico. Molecular analysis procedures included genomic DNA extraction from blood leukocytes in each patient followed by PCR amplification of PABPN1 exon 1, and direct nucleotide sequencing of PCR products. A total of 102 patients with OPMD were included in the study. Expanded PABPN1 gene alleles were demonstrated in all patients: 65% (66 out of 102) had a (GCN)15 expansion while the remaining 35% (36 out of 102) exhibited a (GCN)13 expansion. This is one of the largest series of molecularly confirmed patients with OPMD in a non-Caucasian population. Ethnic-specific differences in the prevalence of specific PABPN1 expansions must be considered for genetic screening of patients with OPMD.
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Affiliation(s)
- Marisa Cruz-Aguilar
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | | | | | - Angel Nava-Castañeda
- Department of Oculoplastics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico.,Faculty of Medicine, Department of Biochemistry, UNAM, Mexico City, Mexico
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Comparison of Two Polypropylene Frontalis Suspension Techniques in 92 Patients With Oculopharyngeal Muscular Dystrophy. Ophthalmic Plast Reconstr Surg 2016; 33:57-60. [PMID: 26866330 DOI: 10.1097/iop.0000000000000648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the functional outcome of the polypropylene trapezoid frontalis suspension with the polypropylene modified Crawford frontalis suspension in a large cohort of patients with oculopharyngeal muscular dystrophy. METHODS Retrospective, nonrandomized comparative case series. Patients with oculopharyngeal muscular dystrophy who underwent bilateral polypropylene frontalis suspension were selected for chart review. Main outcome measures were margin reflex distance, duration of surgery, and ptosis recurrence. RESULTS Ninety-two patients qualified for chart review; 39 patients underwent the trapezoid sling and 53 patients the modified Crawford sling. There was no difference in preoperative margin reflex distance or levator function between the 2 surgical groups. Postoperative improvement in margin reflex distance was 2.95 ± 1.56 mm in the trapezoid group compared with 2.85 ± 1.65 mm in the modified Crawford group (p = 0.67). Duration of surgery was 40.49 ± 13.33 minutes in the trapezoid group compared with 53.77 ± 16.04 minutes in the modified Crawford group (p < 0.001). Five percent of eyes in the trapezoid group had ptosis recurrence compared with 13% of eyes in the modified Crawford group (p = 0.07). CONCLUSION Both polypropylene frontalis suspension techniques generated an equivalent increase in margin reflex distance. However, the trapezoid frontalis suspension required less operative time and trended toward a lower rate of ptosis recurrence.
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Garibaldi M, Pennisi EM, Bruttini M, Bizzarri V, Bucci E, Morino S, Talerico C, Stoppacciaro A, Renieri A, Antonini G. Dropped-head in recessive oculopharyngeal muscular dystrophy. Neuromuscul Disord 2015; 25:869-72. [DOI: 10.1016/j.nmd.2015.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 08/25/2015] [Accepted: 08/26/2015] [Indexed: 10/23/2022]
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The Inhibition of Heat Shock Protein 90 Facilitates the Degradation of Poly-Alanine Expanded Poly (A) Binding Protein Nuclear 1 via the Carboxyl Terminus of Heat Shock Protein 70-Interacting Protein. PLoS One 2015; 10:e0138936. [PMID: 26414348 PMCID: PMC4587574 DOI: 10.1371/journal.pone.0138936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/06/2015] [Indexed: 01/24/2023] Open
Abstract
Background Since the identification of poly-alanine expanded poly(A) binding protein nuclear 1 (PABPN1) as the genetic cause of oculopharyngeal muscular dystrophy (OPMD), considerable progress has been made in our understanding of the pathogenesis of the disease. However, the molecular mechanisms that regulate the onset and progression of the disease remain unclear. Results In this study, we show that PABPN1 interacts with and is stabilized by heat shock protein 90 (HSP90). Treatment with the HSP90 inhibitor 17-AAG disrupted the interaction of mutant PABPN1 with HSP90 and reduced the formation of intranuclear inclusions (INIs). Furthermore, mutant PABPN1 was preferentially degraded in the presence of 17-AAG compared with wild-type PABPN1 in vitro and in vivo. The effect of 17-AAG was mediated through an increase in the interaction of PABPN1 with the carboxyl terminus of heat shock protein 70-interacting protein (CHIP). The overexpression of CHIP suppressed the aggregation of mutant PABPN1 in transfected cells. Conclusions Our results demonstrate that the HSP90 molecular chaperone system plays a crucial role in the selective elimination of abnormal PABPN1 proteins and also suggest a potential therapeutic application of the HSP90 inhibitor 17-AAG for the treatment of OPMD.
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Youssof S, Schrader RM, Romero-Clark C, Roy G, Spafford M. Safety of botulinum toxin for dysphagia in oculopharyngeal muscular dystrophy. Muscle Nerve 2014; 49:601-3. [PMID: 24259282 DOI: 10.1002/mus.24123] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2013] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Despite multiple studies reporting marked benefit of botulinum toxin (BTX) for treatment of cricopharyngeal dysphagia, little is known about its safety for this indication. We examined the safety of cricopharyngeal BTX for dysphagia in oculopharyngeal muscular dystrophy (OPMD). METHODS We reviewed records of patients with OPMD who received cricopharyngeal BTX. RESULTS Twenty-four patients underwent 66 procedures. Overall adverse event frequency was 44%. The most common adverse events were dysphonia (24%) and worsened dysphagia (14%). Logistic regression demonstrated that dose was a significant predictor of worsened dysphagia (P = 0.036) and of the composite event of dysphonia or worsened dysphagia (P = 0.009). There was a nonsignificant trend for dose as a predictor of dysphonia (P = 0.073). 59% of procedures were associated with symptomatic improvement. CONCLUSIONS While BTX appears to be beneficial for treatment of dysphagia in OPMD, caution is warranted when injecting the cricopharyngeus muscle due to dose-related risk of dysphonia or worsened dysphagia.
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Affiliation(s)
- Sarah Youssof
- Department of Neurology, MSC 10 5620, 1 University of New Mexico, Albuquerque, New Mexico, 87131
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Yablonka-Reuveni Z. The skeletal muscle satellite cell: still young and fascinating at 50. J Histochem Cytochem 2012; 59:1041-59. [PMID: 22147605 DOI: 10.1369/0022155411426780] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell's indispensable role in muscle repair has been reaffirmed.
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Affiliation(s)
- Zipora Yablonka-Reuveni
- Department of Biological Structure, University of Washington School of Medicine, Seattle, Washington 98195, USA.
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