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YOKOTA S, KOBATAKE Y, MAEKAWA M, TAKASHIMA S, NISHII N. Trismus due to myotonia associated with hyperadrenocorticism in a dog. J Vet Med Sci 2023; 85:876-879. [PMID: 37357395 PMCID: PMC10466053 DOI: 10.1292/jvms.23-0103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/31/2023] [Indexed: 06/27/2023] Open
Abstract
We present the report of trismus due to hyperadrenocorticism-associated myotonia diagnosed by electromyography in a dog. An intact female Miniature Dachshund, 13 years and 9 months old, presented with stiff gait and trismus as well as polyuria and polydipsia. Abdominal ultrasonography showed enlarged adrenal glands. An adrenocorticotropic hormone stimulation test revealed an exaggerated response. Based on these findings, this case was diagnosed with hyperadrenocorticism. Electromyography revealed myotonic discharge in the temporalis muscle and limbs. Therefore, trismus was considered to be caused by hyperadrenocorticism-associated myotonia, and the case was treated with oral trilostane (1.3 mg/kg, once daily). During the 4-month follow-up period, despite the partial improvement in stiff gait, trismus did not recover. Long-term data on more cases are warranted to assess the prognosis and clinical characteristics of trismus due to hyperadrenocorticism-associated myotonia.
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Affiliation(s)
- Shunya YOKOTA
- Joint Graduate School of Veterinary Sciences, Gifu
University, Gifu, Japan
| | - Yui KOBATAKE
- Joint Department of Veterinary Medicine, Faculty of Applied
Biological Science, Gifu University, Gifu, Japan
| | | | - Satoshi TAKASHIMA
- Joint Department of Veterinary Medicine, Faculty of Applied
Biological Science, Gifu University, Gifu, Japan
| | - Naohito NISHII
- Joint Graduate School of Veterinary Sciences, Gifu
University, Gifu, Japan
- Joint Department of Veterinary Medicine, Faculty of Applied
Biological Science, Gifu University, Gifu, Japan
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Chimenes ND, Caramalac SM, Caramalac SM, Fernandes TD, Basso RM, Cerri FM, Oliveira-Filho JP, Borges AS, Palumbo MIP. A complex CLCN1 variant associated with hereditary myotonia in a mixed-breed dog. J Vet Diagn Invest 2023; 35:413-416. [PMID: 37212506 PMCID: PMC10331391 DOI: 10.1177/10406387231176736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Hereditary myotonia (HM) is characterized by delayed muscle relaxation after contraction as a result of a mutation in the CLCN1 gene. We describe here a complex CLCN1 variant in a mixed-breed dog with clinical and electromyographic signs of HM. Blood samples from the myotonic dog, as well as from his male littermate and parents, were analyzed via amplification of the 23 exons encoding CLCN1. After sequencing the CLCN1 gene, a complex variant was found in exon 6 c.[705T>G; 708del; 712_732del], resulting in a premature stop codon in exon 7 and a protein that was 717 amino acids shorter than the normal CLC protein. The myotonic dog was identified as homozygous recessive for the complex CLCN1 variant; its parents were heterozygous, and its male littermate was homozygous wild-type. Knowledge of the CLCN1 mutations responsible for the development of hereditary myotonia allows greater clarification of this condition.
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Affiliation(s)
- Natielly D. Chimenes
- Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Silvana M. Caramalac
- Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Simone M. Caramalac
- Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Thiago D. Fernandes
- Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Roberta M. Basso
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, São Paulo State University (Unesp), Botucatu, São Paulo, Brazil
| | - Fabrício M. Cerri
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, São Paulo State University (Unesp), Botucatu, São Paulo, Brazil
| | - José P. Oliveira-Filho
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, São Paulo State University (Unesp), Botucatu, São Paulo, Brazil
| | - Alexandre S. Borges
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, São Paulo State University (Unesp), Botucatu, São Paulo, Brazil
| | - Mariana I. P. Palumbo
- Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
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3
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Golinelli S, Fracassi F, Bianchi E, Pöppl ÁG, Miceli DD, Benedicenti L, De Marco V, Cook AK, Espada Castro L, Ramsey I, Seo KW, Cantile C, Gandini G, Hulsebosch SE, Feldman EC. Clinical features of muscle stiffness in 37 dogs with concurrent naturally occurring hypercortisolism. J Vet Intern Med 2023; 37:578-585. [PMID: 36798032 DOI: 10.1111/jvim.16620] [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: 02/07/2022] [Accepted: 12/14/2022] [Indexed: 02/18/2023] Open
Abstract
BACKGROUND Severe muscle stiffness (SMS) in dogs with hypercortisolism (HC) is uncommon. OBJECTIVES To evaluate signalment, presentation, treatments, and long-term outcomes of dogs with concurrent HC and SMS. ANIMALS Thirty-seven dogs. METHODS Medical records of dogs with HC and concurrent SMS were recruited from 10 institutions. Clinical information, test results, therapeutic responses, and survival times were reviewed. RESULTS All 37 dogs with HC and SMS had pituitary-dependent hypercortisolism (PDH); 36/37 weighed <20 kg. Signs and test results were typical of PDH aside from SMS, initially diagnosed in all 4 limbs in 9, pelvic limbs of 22, and thoracic limbs of 6 dogs. Hypercortisolism and SMS were diagnosed together in 3 dogs; HC 1-36 months before SMS in 23; SMS 1-12 months before HC in 11. Mitotane or trilostane, given to control HC in 36/37 dogs, improved or resolved HC signs in 28; SMS did not resolve, remaining static or worsening in 31/36 dogs, mildly improving in 5/19 dogs given additional therapies. Progression of SMS included additional limbs in 10 dogs and the masticatory muscles of 2. The median survival time from diagnosis of SMS was 965 days (range, 8-1188). CONCLUSIONS AND CLINICAL IMPORTANCE Concurrent SMS and HC is uncommon, possibly affecting only dogs with PDH. Development of SMS might occur before or after diagnosis of HC. Apart from SMS, the clinical picture and survival time of these dogs seem indistinguishable from those of dogs with HC in general. However, while muscle weakness usually resolves with HC treatment SMS does not.
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Affiliation(s)
- Stefania Golinelli
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Federico Fracassi
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Ezio Bianchi
- Department of Veterinary Medical Sciences, University of Parma, Parma, Italy
| | - Álan Gomes Pöppl
- Department of Animal Medicine, Faculty of Veterinary, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Diego Daniel Miceli
- Endocrinology Unit, School of Veterinary Medicine, University of Buenos Aires, Faculty of Veterinary Sciences, Buenos Aires, Argentina
| | - Leontine Benedicenti
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Audrey K Cook
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | | | - Ian Ramsey
- School of Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Kyoung Won Seo
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Carlo Cantile
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Gualtiero Gandini
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Sean E Hulsebosch
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Edward C Feldman
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
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4
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Rodrigues DDJ, Damasceno AD, Araújo CETD, Torelli SR, Fonseca LGH, Delfiol DJZ, Oliveira-Filho JPD, Araújo-Júnior JP, Borges AS. Hereditary myotonia in American Bulldog associated with a novel frameshift mutation in the CLCN1 gene. Neuromuscul Disord 2020; 30:991-998. [PMID: 33246886 DOI: 10.1016/j.nmd.2020.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 10/06/2020] [Accepted: 10/16/2020] [Indexed: 11/19/2022]
Abstract
Hereditary myotonia (HM) is a genetic disorder that occurs due to mutations in the chloride channel and results in delayed relaxation of the skeletal muscles. HM has been described in 12 dog breeds, and in five of them, molecular studies of this disorder were performed and mutations in the CLCN1 gene were described. In this study, an affected American Bulldog with HM clinically characterized by muscle hypertrophy, myotonic discharges, and nondystrophic myotonia with a "warm-up" phenomenon was evaluated, and the candidate canine CLCN1 gene was sequenced. The molecular analysis revealed a frameshift mutation NM_001003124.2:c.436_437insCTCT that resulted in a frameshift and a premature stop codon NP_001003124.1:pTyr146SerfsTer49 . Two aberrant alternative CLCN1 transcripts were observed in an affected dog, the expected transcript with the 4 bp insertion, NM_001003124.2:r.436_437insctct, and an unexpected transcript containing parts of intron 6 in addition to the insertion in exon 4, NM_001003124.2:[r.436_437insctct;r.774_775ins79]. In conclusion, the frameshift mutation in the CLCN1 gene is associated with autosomal recessive HM in American Bulldog and this study constitutes the first description of the disease in this breed.
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Affiliation(s)
- Daiane de Jesus Rodrigues
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil. Rua Prof. Dr. Walter Maurício Corrêa, s/n, Botucatu, SP, Brazil
| | - Adilson Donizeti Damasceno
- School of Veterinary and Animal Science, Universidade Federal de Goiás, Goiânia, Goiás, Brazil. Rodovia Goiânia, km 8 s/n Campus - Samambaia, Goiânia, GO 74001-970, Brazil
| | - César Erineudo Tavares de Araújo
- University Center UNILEAO, Juazeiro do Norte, Ceará, Brazil. Av. Maria Letícia Leite Pereira s/n, Lagoa Seca - Cidade Universitária, Juazeiro do Norte, CE 63040-405, Brazil
| | - Sandra Regina Torelli
- CALE - Animal Surgery and Specialized Diagnostic Laboratory, Jundiaí, São Paulo, Brazil, Rua Itália, 106 - Jardim Bonfiglioli, Jundiaí, SP 13207-280, Brazil
| | - Luine Gabriela Hilário Fonseca
- Self-employed Veterinary, Catalão, Goiás, Brazil, Rua Paraná, 330 - Nossa senhora de Fátima, Catalão, GO 75709-240, Brazil
| | - Diego José Zanzarini Delfiol
- School of Veterinary Medicine, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brazil, Av. Mato Grosso, 3289 - Bloco 2S - Umuarama, Uberlândia, MG 38405-314, Brazil
| | - José Paes de Oliveira-Filho
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil. Rua Prof. Dr. Walter Maurício Corrêa, s/n, Botucatu, SP 18618-681, Brazil
| | - João Pessoa Araújo-Júnior
- Institute of Biotechnology, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil. Alameda das Tecomarias, s/n - Chácara Capão Bonito, Botucatu, SP 18607-440, Brazil
| | - Alexandre Secorun Borges
- Department of Veterinary Clinical Science, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil. Rua Prof. Dr. Walter Maurício Corrêa, s/n, Botucatu, SP 18618-681, Brazil.
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5
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Myotonia congenita in a Labrador Retriever with truncated CLCN1. Neuromuscul Disord 2018; 28:597-605. [DOI: 10.1016/j.nmd.2018.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/29/2018] [Accepted: 05/07/2018] [Indexed: 11/20/2022]
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6
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Gandolfi B, Daniel RJ, O'Brien DP, Guo LT, Youngs MD, Leach SB, Jones BR, Shelton GD, Lyons LA. A novel mutation in CLCN1 associated with feline myotonia congenita. PLoS One 2014; 9:e109926. [PMID: 25356766 PMCID: PMC4214686 DOI: 10.1371/journal.pone.0109926] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/05/2014] [Indexed: 12/30/2022] Open
Abstract
Myotonia congenita (MC) is a skeletal muscle channelopathy characterized by inability of the muscle to relax following voluntary contraction. Worldwide population prevalence in humans is 1∶100,000. Studies in mice, dogs, humans and goats confirmed myotonia associated with functional defects in chloride channels and mutations in a skeletal muscle chloride channel (CLCN1). CLCN1 encodes for the most abundant chloride channel in the skeletal muscle cell membrane. Five random bred cats from Winnipeg, Canada with MC were examined. All cats had a protruding tongue, limited range of jaw motion and drooling with prominent neck and proximal limb musculature. All cats had blepharospasm upon palpebral reflex testing and a short-strided gait. Electromyograms demonstrated myotonic discharges at a mean frequency of 300 Hz resembling the sound of a ‘swarm of bees’. Muscle histopathology showed hypertrophy of all fiber types. Direct sequencing of CLCN1 revealed a mutation disrupting a donor splice site downstream of exon 16 in only the affected cats. In vitro translation of the mutated protein predicted a premature truncation and partial lack of the highly conserved CBS1 (cystathionine β-synthase) domain critical for ion transport activity and one dimerization domain pivotal in channel formation. Genetic screening of the Winnipeg random bred population of the cats' origin identified carriers of the mutation. A genetic test for population screening is now available and carrier cats from the feral population can be identified.
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Affiliation(s)
- Barbara Gandolfi
- Department of Veterinary Medicine and Surgery, School of Veterinary Medicine, University of Missouri – Columbia, Columbia, Missouri, United States of America
- * E-mail:
| | - Rob J. Daniel
- Department of Veterinary Medicine and Surgery, School of Veterinary Medicine, University of Missouri – Columbia, Columbia, Missouri, United States of America
| | - Dennis P. O'Brien
- Department of Veterinary Medicine and Surgery, School of Veterinary Medicine, University of Missouri – Columbia, Columbia, Missouri, United States of America
| | - Ling T. Guo
- Department of Pathology, University of California San Diego, La Jolla, California, United States of America
| | | | - Stacey B. Leach
- Department of Veterinary Medicine and Surgery, School of Veterinary Medicine, University of Missouri – Columbia, Columbia, Missouri, United States of America
| | - Boyd R. Jones
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - G. Diane Shelton
- Department of Pathology, University of California San Diego, La Jolla, California, United States of America
| | - Leslie A. Lyons
- Department of Veterinary Medicine and Surgery, School of Veterinary Medicine, University of Missouri – Columbia, Columbia, Missouri, United States of America
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7
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Myokymia and neuromyotonia in veterinary medicine: a comparison with peripheral nerve hyperexcitability syndrome in humans. Vet J 2013; 197:153-62. [PMID: 23583699 DOI: 10.1016/j.tvjl.2013.03.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/12/2013] [Accepted: 03/04/2013] [Indexed: 01/17/2023]
Abstract
Involuntary muscle hyperactivity can result from muscle or peripheral nerve hyperexcitability or central nervous system dysfunction. In humans, diseases causing hyperexcitability of peripheral nerves are grouped together under the term 'peripheral nerve hyperexcitability' (PNH). Hyperexcitability of the peripheral motor nerve can result into five different phenotypic main variants, i.e. fasciculations, myokymia, neuromyotonia, cramps and tetany, each with their own clinical and electromyographic characteristics. This review focuses on the most commonly described expressions of PNH in veterinary medicine, i.e. myokymia and neuromyotonia, in particular in young Jack Russell terriers. Data from 58 veterinary cases with generalized myokymia and neuromyotonia were analyzed, including unpublished treatment and follow-up data on eight Jack Russell terriers from a previous study and seven additional Jack Russell terriers. A dysfunction of the potassium channel or its associated proteins has been found in many human syndromes characterized by PNH, in particular in generalized myokymia and neuromyotonia, and is suspected to occur in veterinary medicine. Potential pathomechanisms of potassium channel dysfunction leading to signs of PNH are broad and include genetic mutations, antibody-mediated attack or ion channel maldistribution due to axonal degeneration or demyelination. A more accurate classification of the different PNH syndromes will facilitate a more rapid diagnosis and guide further research into natural occurring PNH in animals.
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8
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Gaschen F, Jaggy A, Jones B. Congenital diseases of feline muscle and neuromuscular junction. J Feline Med Surg 2004; 6:355-66. [PMID: 15546767 PMCID: PMC10822525 DOI: 10.1016/j.jfms.2004.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2004] [Indexed: 10/26/2022]
Abstract
Although muscle diseases occur relatively rarely in cats, a number of congenital feline myopathies have been described over the last 20 years and are reviewed in this paper. Some of them have been reported exclusively in specific breeds, including the hypokalaemic myopathy of Burmese cats, type IV glycogen storage disease in Norwegian Forest cats, or the myopathy of Devon Rex. Other congenital disorders of muscle and neuromuscular junction such as myotonia congenita, dystrophin-deficient hypertrophic feline muscular dystrophy, laminin alpha2 deficiency, or congenital myasthenia gravis may occur in any cat. A systematic approach is essential in order to efficiently obtain a timely diagnosis in cats showing signs of muscle disease. After a thorough clinical examination, this approach includes blood analyses (eg, serum concentration of muscle enzymes), electrophysiology where available (electromyography, nerve conduction studies), and sampling of muscle biopsies for histological, histochemical and immunohistochemical evaluation. When available, detection of healthy carriers of these genetic disorders is important to eliminate the gene mutations from breeding families. Clinicians regularly receiving feline patients must have a good knowledge of congenital feline myopathies and the features which enable a diagnosis to be made and prognosis given. Besides preserving or restoring the well-being of the myopathic patient, rapid and efficient information and counselling of the breeders are of central importance in order to prevent the recurrence of the problem in specific breeding lines.
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Affiliation(s)
- Frédéric Gaschen
- Division of Small Animal Internal Medicine, Department of Clinical Veterinary Medicine, Faculty of Veterinary Medicine, University of Bern, Laenggass-str. 128, 3001 Bern, Switzerland.
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Affiliation(s)
- Michael Podell
- Animal Emergency and Critical Care Center, 1810 Frontage Road, Northbrook, IL 60089, USA.
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10
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Abstract
Neuromuscular disease can present even the most astute clinician with a challenging diagnostic dilemma. This article focuses on the neuroanatomy and the historical, physical, and neurologic examination findings observed in many of the neuromuscular disorders affecting dogs and cats. In addition, some common laboratory tests and imaging modalities used in the diagnosis of neuromuscular disease, including routine radiography, computed tomography, and magnetic resonance imaging, are discussed. A brief discussion of sensory nerve disorders is also presented.
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Affiliation(s)
- Eric N Glass
- Section of Neurology and Neurosurgery, Red Bank Veterinary Hospital, New Jersey 07701, USA.
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11
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Abstract
Altered excitability of the skeletal muscle membrane (sarcolemma) can result in clinical signs of muscle dysfunction. Hyperexcitability of the sarcolemma results in myotonia, and hypoexcitability results in paresis or paralysis. Our understanding of the physiologic and molecular bases of disorders of sarcolemmal excitability is rapidly increasing as techniques for evaluation are improved. This article reviews muscle excitability disorders in dogs and cats and their pathogenesis.
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Affiliation(s)
- Charles H Vite
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104, USA.
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12
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Gracis M, Keith D, Vite CH. Dental and craniofacial findings in eight miniature schnauzer dogs affected by myotonia congenita: preliminary results. J Vet Dent 2000; 17:119-27. [PMID: 11968937 DOI: 10.1177/089875640001700301] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Myotonia is a clinical sign characterized by the delay of skeletal muscle relaxation following the cessation of a voluntary activity or the termination of an electrical or mechanical stimulus. Recently, Miniature Schnauzers with myotonia congenita associated with defective chloride ion conductance across the skeletal muscle membrane were identified. Congenital myotonia in these dogs appears to follow an autosomal recessive mode of inheritance. Craniofacial and dental findings of eight Miniature Schnauzer dogs with myotonia congenita are described in the present paper. These findings include: delayed dental eruption of both deciduous and permanent dentition: persistent deciduous dentition; unerupted or partially erupted permanent teeth: crowding and rotation of premolar and or incisor teeth: missing teeth: increased interproximal space between the maxillary fourth premolar and first molar teeth: decreased interproximal space between the maxillary canine and lateral incisor teeth: inability to fully close the mouth due to malocclusion: distoclusion: and, decreased mandibular range of motion. A long narrow skull with a flattened zygomatic arch and greater mandibular body curvature were also consistent findings in the affected dogs. The small number of dogs studied prevents conclusive statements about the origin of these abnormalities, however it is interesting that only 1 of 45 unaffected Miniature Schnauzer dogs showed similar traits.
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Affiliation(s)
- M Gracis
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey Street, #3113, Philadelphia, PA 19104-6010, USA
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13
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Abstract
Two dogs developed a disabling gait abnormality characterised by stiffness. The abnormality was consistent with a diagnosis of myotonia secondary to hyperadrenocorticism. The first dog had iatrogenic hyperadrenocorticism, and its signs improved substantially after corticosteroid administration was gradually withdrawn. The second had pituitary-dependent hyperadrenocorticism, but myotonic signs progressed despite effective mitotane therapy. Procainamide administration reduced the myotonic stiffness in the second case.
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Affiliation(s)
- G R Swinney
- Department of Veterinary Clinical Sciences, University of Sydney, New South Wales
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14
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Abstract
Four closely related domestic shorthair kittens were investigated following the detection of abnormalities in their gait, difficulty opening their mouths and muscle hypertrophy. They walked with a stiff, stilted gait, with the stiffness reducing during exercise. Startling of the kittens resulted in hyperextension of the limbs and falling to lateral recumbency, or spasm of the orbicularis oculi muscle, prolonged prolapse of the nictitating membranes and flattening of the ears. One kitten was intermittently dysphonic. Endotracheal intubation of the anaesthetised kittens was difficult due to an inability to open the mouth to a wide angle, and narrowing of the glottis due to muscle spasm. A diagnosis of congenital myotonia was made based on the clinical signs, the kittens' ages, typical myotonic discharges on electromyography, and the histopathological and histochemical findings in muscle. This is the first report of congenital myotonia in this species.
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Affiliation(s)
- F H Hickford
- Veterinary Teaching Hospital, Cornell University, Ithaca, NY 14853, USA
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15
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Braga IS, Oda K, Kikuchi T, Tanaka S, Shin Y, Sento M, Itakura C, Mizutani M. A new inherited muscular disorder in Japanese quails (Coturnix coturnix japonica). Vet Pathol 1995; 32:351-60. [PMID: 7483209 DOI: 10.1177/030098589503200403] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Thirteen adult mutant (LWC strain) Japanese quails (Coturnix coturnix japonica), between the ages of 8 and 60 weeks were examined for a progressive muscular disorder. The disorder, inherited as an autosomal dominant trait, was clinically apparent as early as 28 days of age; it was characterized by generalized myotonia, muscle stiffness, and muscle weakness. Affected birds were identified by their inability to lift their wings vertically upward and by their inability to right themselves when placed on their dorsum. Electromyographic studies in two mutant quails showed high-frequency repetitive discharges comparable to those of myotonic runs. These discharges persisted after nerve resection. The distinctive histopathologic changes in the various muscles examined were ring fibers, sarcoplasmic masses, and internal migration of sarcolemmal nuclei. A slight decrease in the size of type IIB muscle fibers and a slight increase in the size of type IIA fibers were observed in the M. pectoralis thoracicus of affected quails. In older affected birds, inter- and intrafascicular fatty infiltration with replacement of type IIB fibers by fat cells was seen in the pectoral muscles. Single fiber necrosis, nonspecific lymphorrages, and variations in the muscle fiber size and shape were also noted. The typical muscle lesions and multisystem involvement, which was manifested by testicular degeneration and atrophy in the male LWC specimens and bilateral lenticular cataracts in 6 of 13 affected mutant quails, suggest resemblance of this new inherited muscular disorder to myotonic dystrophy in man.
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Affiliation(s)
- I S Braga
- Department of Comparative Pathology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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16
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Aktas M, Auguste D, Lefebvre HP, Toutain PL, Braun JP. Creatine kinase in the dog: a review. Vet Res Commun 1993; 17:353-69. [PMID: 8209415 DOI: 10.1007/bf01839386] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the dog, creatine kinase (CK) is mostly present in the skeletal muscles, myocardium, brain and intestine. The MM isoenzyme predominates in muscles and myocardium. In plasma, reference values depend on the technique used and CK-MB accounts for about 30-45% of total CK activity. Sex has no influence on plasma CK activity, which is higher in young dogs than in adults. Plasma CK is elevated after physical exercise. After its release from the cells, CK reaches the plasma mostly via the lymphatic route and then remains in the plasma compartment. It is rapidly cleared with a half-life of about 2 hours. Muscle diseases are the main source of plasma CK elevations: inherited myopathies, malignant hyperthermia, hypothyroidism, vitamin E-selenium deficiency, prolonged decubitus, intramuscular injections, surgery, etc. Plasma CK is also increased in experimental myocardial infarction, for which the dog is an interesting model, allowing quantification of the damage by measuring the total CK activity released.
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Affiliation(s)
- M Aktas
- Department of Physiopathology, Ecole Nationale Vétérinaire, Toulouse, France
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Poncelet L, Gilbert S, Snaps F, Balligand M. A regional curare test for evaluation of myotonia in dogs. J Small Anim Pract 1992. [DOI: 10.1111/j.1748-5827.1992.tb01180.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hegreberg GA, Reed SM. Skeletal muscle changes associated with equine myotonic dystrophy. Acta Neuropathol 1990; 80:426-31. [PMID: 2239155 DOI: 10.1007/bf00307698] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A progressive neuromuscular disorder in young horses, clinically apparent as early as 1 month of age, is characterized by generalized myotonia, muscle stiffness, muscle weakness and atrophy. Myotonia is identified by percussion dimpling and myotonic EMG discharges. Changes in one case included testicular hypoplasia, cataract formation, and glucose intolerance, indicating a systemic involvement. Pathologic changes in skeletal muscles from three affected foals were examined. Sarcoplasmic masses, ringed fibers, internal positioning of sarcolemmal nuclei, and nuclear rowing were among the primary histologic changes noted. Variation in fiber diameter size, especially atrophy, and type I predominance were also prominent changes. A neurogenic involvement was indicated by type grouping changes in several muscles.
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Affiliation(s)
- G A Hegreberg
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040
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Reed SM, Hegreberg GA, Bayly WM, Brown CM, Paradis MR, Clemmons RM. Progressive myotonia in foals resembling human dystrophia myotonica. Muscle Nerve 1988; 11:291-6. [PMID: 3398875 DOI: 10.1002/mus.880110403] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A severe and progressive neuromuscular disorder accompanied by clinical, electrophysiological, and pathological features resembling human dystrophia myotonica was observed in three foals. This disorder was apparent as early as 1 month of age and involved progressive skeletal muscle dysfunction, initially characterized by proximal muscle hypertrophy and hypertonicity with subsequent muscle stiffness, weakness, and atrophy. Multisystem involvement was manifested in one case by testicular hypoplasia, early cataract formation, and borderline glucose intolerance. Prolonged dimpling of these large rear-limb muscles was elicited by percussion. Myotonic discharges were identified by electromyography. Percussion dimpling and the typical myotonic discharges persisted after neuromuscular blockade. Distinctive histologic muscle changes included ring fibers, sarcoplasmic mass formation, variation in fiber diameter size, and internally positioned nuclei.
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Affiliation(s)
- S M Reed
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, Washington State University, Pullman
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Jamison JM, Baird JD, Smith-Maxie LL, Hulland TJ. A congenital form of myotonia with dystrophic changes in a quarterhorse. Equine Vet J 1987; 19:353-8. [PMID: 3622468 DOI: 10.1111/j.2042-3306.1987.tb01433.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Amann JF. Congenital and acquired neuromuscular disease of young dogs and cats. Vet Clin North Am Small Anim Pract 1987; 17:617-39. [PMID: 3300000 DOI: 10.1016/s0195-5616(87)50057-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Neuromuscular disorders in small animals include a diverse group of congenital and acquired diseases. The prognosis will vary according to the disorder and the portion of the motor unit affected. A number of diseases might be satisfactorily treated (for example, myasthenia gravis, congenital myotonia), whereas others may be self-limiting (for example, hereditary myopathy of Labrador Retrievers). Accurate diagnosis is necessary for establishing a prognosis and treatment plan suitable to the patient and client. Specific diagnosis in the absence of specialized tests is difficult, although not always impossible (for example, congenital myotonia in the Chow Chow). A knowledge of the neuromuscular diseases that might affect small animals, a detailed history, and a thorough physical examination will help in the presumptive diagnosis. Specialized laboratory examinations may need to be applied (for example, antiacetylcholine receptor antibody titer for acquired myasthenia gravis). Referral may be necessary for more detailed diagnostic workup (for example, electromyographic examination, nerve or muscle biopsy examination). In the case of inherited neuromuscular disorders, a knowledge of inheritance patterns will allow genetic counseling to avoid future problem breedings.
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Abstract
A review of the literature concerning the application of electromyography and electroneurography in canine neurology is presented. Measurements of amplitude and duration of motor unit potentials in normal dogs varied largely in the various reports. It was therefore concluded that these measurements are of limited clinical value. The results of motor and sensory nerve conduction studies in normal dogs are summarised. The differences between the methods used are discussed. It is concluded that variations in reported normal values are due mainly to differences in method. The application of electromyography and electroneurography in neuromuscular disorders in the dog is systematically presented, based upon the reported diagnoses. The considerable number of first descriptions of newly-recognised and described neuromuscular diseases appears to be related to the introduction of neuromuscular electrophysiology into veterinary medicine.
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