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Clinical manifestations and diagnosis of inclusion body myositis

Marc L Miller, MD
Thomas E Lloyd, MD, PhD
Section Editors
Ira N Targoff, MD
Jeremy M Shefner, MD, PhD
Deputy Editor
Monica Ramirez Curtis, MD, MPH


Sporadic inclusion body myositis (IBM) is classified along with polymyositis, dermatomyositis, and autoimmune necrotizing myopathy as one of the idiopathic inflammatory myopathies. However, despite some similarities, the clinicopathologic manifestations of IBM are clearly distinct from the other disorders (table 1). (See "Clinical manifestations of dermatomyositis and polymyositis in adults".)

The clinical manifestations and diagnosis of IBM will be reviewed here. The treatment and prognosis are discussed separately. (See "Management of inclusion body myositis".)


Inclusion body myositis (IBM) is a rare sporadic disorder with a prevalence that is estimated at five to nine cases per million adults [1-3]; however, some estimates of prevalence have been as high as 70 per million population [4]. There is a paucity of data on the annual incidence; the reported range in two studies is from 1 to 7.9 per million [4,5]. Due to the high incidence of weakness complaints in older adults and the insidious onset of weakness in IBM, this disease is frequently misdiagnosed [3]. Indeed, it is the most common acquired idiopathic inflammatory myopathy in individuals over the age of 50 [3].

The disease affects men more often than women [6]. The mean age at onset of symptoms is approximately 60 years, with a range from the fourth to the ninth decade.


Symptoms and signs — Patients with inclusion body myositis (IBM) present with the insidious onset of weakness. The average duration of symptoms before diagnosis is about five years [3,7]. The most common initial presentation is slowly progressive proximal leg weakness, with difficulty getting up out of a chair or frequent falls. In some patients, the initial complaint may be with weakness of grip strength, such as difficulty opening jars. Rarely, patients may present with isolated dysphagia [7].

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Literature review current through: Nov 2017. | This topic last updated: Mar 07, 2016.
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  1. Badrising UA, Maat-Schieman M, van Duinen SG, et al. Epidemiology of inclusion body myositis in the Netherlands: a nationwide study. Neurology 2000; 55:1385.
  2. Phillips BA, Zilko PJ, Mastaglia FL. Prevalence of sporadic inclusion body myositis in Western Australia. Muscle Nerve 2000; 23:970.
  3. Needham M, Corbett A, Day T, et al. Prevalence of sporadic inclusion body myositis and factors contributing to delayed diagnosis. J Clin Neurosci 2008; 15:1350.
  4. Wilson FC, Ytterberg SR, St Sauver JL, Reed AM. Epidemiology of sporadic inclusion body myositis and polymyositis in Olmsted County, Minnesota. J Rheumatol 2008; 35:445.
  5. Kaipiainen-Seppänen O, Aho K. Incidence of rare systemic rheumatic and connective tissue diseases in Finland. J Intern Med 1996; 240:81.
  6. Dimachkie MM, Barohn RJ. Inclusion body myositis. Neurol Clin 2014; 32:629.
  7. Benveniste O, Guiguet M, Freebody J, et al. Long-term observational study of sporadic inclusion body myositis. Brain 2011; 134:3176.
  8. Lloyd TE, Mammen AL, Amato AA, et al. Evaluation and construction of diagnostic criteria for inclusion body myositis. Neurology 2014; 83:426.
  9. Cox FM, Titulaer MJ, Sont JK, et al. A 12-year follow-up in sporadic inclusion body myositis: an end stage with major disabilities. Brain 2011; 134:3167.
  10. Amato AA, Gronseth GS, Jackson CE, et al. Inclusion body myositis: clinical and pathological boundaries. Ann Neurol 1996; 40:581.
  11. Beyenburg S, Zierz S, Jerusalem F. Inclusion body myositis: clinical and histopathological features of 36 patients. Clin Investig 1993; 71:351.
  12. Felice KJ, North WA. Inclusion body myositis in Connecticut: observations in 35 patients during an 8-year period. Medicine (Baltimore) 2001; 80:320.
  13. Wintzen AR, Bots GT, de Bakker HM, et al. Dysphagia in inclusion body myositis. J Neurol Neurosurg Psychiatry 1988; 51:1542.
  14. Riminton DS, Chambers ST, Parkin PJ, et al. Inclusion body myositis presenting solely as dysphagia. Neurology 1993; 43:1241.
  15. Lotz BP, Engel AG, Nishino H, et al. Inclusion body myositis. Observations in 40 patients. Brain 1989; 112 ( Pt 3):727.
  16. Koffman BM, Rugiero M, Dalakas MC. Immune-mediated conditions and antibodies associated with sporadic inclusion body myositis. Muscle Nerve 1998; 21:115.
  17. Vattemi G, Tonin P, Marini M, et al. Sarcoidosis and inclusion body myositis. Rheumatology (Oxford) 2008; 47:1433.
  18. Amato AA, Barohn RJ. Inclusion body myositis: old and new concepts. J Neurol Neurosurg Psychiatry 2009; 80:1186.
  19. Engel WK, Askanas V. Inclusion-body myositis: clinical, diagnostic, and pathologic aspects. Neurology 2006; 66:S20.
  20. Larman HB, Salajegheh M, Nazareno R, et al. Cytosolic 5'-nucleotidase 1A autoimmunity in sporadic inclusion body myositis. Ann Neurol 2013; 73:408.
  21. Pluk H, van Hoeve BJ, van Dooren SH, et al. Autoantibodies to cytosolic 5'-nucleotidase 1A in inclusion body myositis. Ann Neurol 2013; 73:397.
  22. Greenberg SA. Cytoplasmic 5'-nucleotidase autoantibodies in inclusion body myositis: Isotypes and diagnostic utility. Muscle Nerve 2014; 50:488.
  23. Lloyd TE, Christopher-Stine L, Pinal-Fernandez I, et al. Cytosolic 5'-Nucleotidase 1A As a Target of Circulating Autoantibodies in Autoimmune Diseases. Arthritis Care Res (Hoboken) 2016; 68:66.
  24. Herbert MK, Stammen-Vogelzangs J, Verbeek MM, et al. Disease specificity of autoantibodies to cytosolic 5'-nucleotidase 1A in sporadic inclusion body myositis versus known autoimmune diseases. Ann Rheum Dis 2016; 75:696.
  25. http://neuromuscular.wustl.edu/over/labdis.html (Accessed on October 01, 2015).
  26. Uruha A, Noguchi S, Hayashi YK, et al. Hepatitis C virus infection in inclusion body myositis: A case-control study. Neurology 2016; 86:211.
  27. Dalakas MC, Schmidt J. Viruses in IBM: Hit-and-run, hide and persist, or irrelevant? Neurology 2016; 86:204.
  28. Kula RW, Sawchak JA, Sher JH. Inclusion body myositis. Curr Opin Rheumatol 1989; 1:460.
  29. Sayers ME, Chou SM, Calabrese LH. Inclusion body myositis: analysis of 32 cases. J Rheumatol 1992; 19:1385.
  30. Dion E, Cherin P, Payan C, et al. Magnetic resonance imaging criteria for distinguishing between inclusion body myositis and polymyositis. J Rheumatol 2002; 29:1897.
  31. Cox FM, Reijnierse M, van Rijswijk CS, et al. Magnetic resonance imaging of skeletal muscles in sporadic inclusion body myositis. Rheumatology (Oxford) 2011; 50:1153.
  32. Tasca G, Monforte M, De Fino C, et al. Magnetic resonance imaging pattern recognition in sporadic inclusion-body myositis. Muscle Nerve 2015; 52:956.
  33. Engel AG, Arahata K. Monoclonal antibody analysis of mononuclear cells in myopathies. II: Phenotypes of autoinvasive cells in polymyositis and inclusion body myositis. Ann Neurol 1984; 16:209.
  34. Lindgren U, Roos S, Hedberg Oldfors C, et al. Mitochondrial pathology in inclusion body myositis. Neuromuscul Disord 2015; 25:281.
  35. Mendell JR, Sahenk Z, Gales T, Paul L. Amyloid filaments in inclusion body myositis. Novel findings provide insight into nature of filaments. Arch Neurol 1991; 48:1229.
  36. Salajegheh M, Pinkus JL, Taylor JP, et al. Sarcoplasmic redistribution of nuclear TDP-43 in inclusion body myositis. Muscle Nerve 2009; 40:19.
  37. Hiniker A, Daniels BH, Lee HS, Margeta M. Comparative utility of LC3, p62 and TDP-43 immunohistochemistry in differentiation of inclusion body myositis from polymyositis and related inflammatory myopathies. Acta Neuropathol Commun 2013; 1:29.
  38. Brady S, Squier W, Sewry C, et al. A retrospective cohort study identifying the principal pathological features useful in the diagnosis of inclusion body myositis. BMJ Open 2014; 4:e004552.
  39. Griggs RC, Askanas V, DiMauro S, et al. Inclusion body myositis and myopathies. Ann Neurol 1995; 38:705.
  40. Calabrese LH, Mitsumoto H, Chou SM. Inclusion body myositis presenting as treatment-resistant polymyositis. Arthritis Rheum 1987; 30:397.
  41. Needham M, Mastaglia FL. Inclusion body myositis: current pathogenetic concepts and diagnostic and therapeutic approaches. Lancet Neurol 2007; 6:620.
  42. Dalakas MC. Sporadic inclusion body myositis--diagnosis, pathogenesis and therapeutic strategies. Nat Clin Pract Neurol 2006; 2:437.
  43. Rose MR, ENMC IBM Working Group. 188th ENMC International Workshop: Inclusion Body Myositis, 2-4 December 2011, Naarden, The Netherlands. Neuromuscul Disord 2013; 23:1044.
  44. van der Meulen MF, Bronner IM, Hoogendijk JE, et al. Polymyositis: an overdiagnosed entity. Neurology 2003; 61:316.
  45. Askanas V. New developments in hereditary inclusion body myopathies. Ann Neurol 1997; 41:421.
  46. Ranque-Francois B, Maisonobe T, Dion E, et al. Familial inflammatory inclusion body myositis. Ann Rheum Dis 2005; 64:634.
  47. Nishino I, Noguchi S, Murayama K, et al. Distal myopathy with rimmed vacuoles is allelic to hereditary inclusion body myopathy. Neurology 2002; 59:1689.
  48. Eisenberg I, Avidan N, Potikha T, et al. The UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene is mutated in recessive hereditary inclusion body myopathy. Nat Genet 2001; 29:83.
  49. Yabe I, Higashi T, Kikuchi S, et al. GNE mutations causing distal myopathy with rimmed vacuoles with inflammation. Neurology 2003; 61:384.
  50. Taylor JP. Multisystem proteinopathy: intersecting genetics in muscle, bone, and brain degeneration. Neurology 2015; 85:658.
  51. Kimonis VE, Kovach MJ, Waggoner B, et al. Clinical and molecular studies in a unique family with autosomal dominant limb-girdle muscular dystrophy and Paget disease of bone. Genet Med 2000; 2:232.
  52. Watts GD, Wymer J, Kovach MJ, et al. Inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia is caused by mutant valosin-containing protein. Nat Genet 2004; 36:377.
  53. Hokkoku K, Sonoo M, Higashihara M, et al. Electromyographs of the flexor digitorum profundus muscle are useful for the diagnosis of inclusion body myositis. Muscle Nerve 2012; 46:181.