Journal of Neurology

, Volume 257, Issue 12, pp 2015–2019 | Cite as

Myasthenia gravis: a changing pattern of incidence

  • I. CasettaEmail author
  • E. Groppo
  • R. De Gennaro
  • E. Cesnik
  • L. Piccolo
  • S. Volpato
  • E. Granieri
Original Communication


The annual incidence of myasthenia gravis (MG) ranges from 3 to 30 per 1,000,000 people. Since the mid-1980s, an increasing incidence has been reported, mainly due to late-onset MG. Whether the increase was due to population aging, improved diagnosis and case collection, or a true excess of incidence cases is still under debate. We used a complete enumeration approach by reviewing all possible sources of case collection in the province of Ferrara, Italy, to estimate the MG incidence and its temporal trend over the study period (1985–2007). The mean annual age-adjusted incidence of MG was 18 per 1,000,000, without any significant temporal trend. The incidence rates in the period 1985–1990 were 14 both for early and late-onset MG. Thereafter, a significant increase in incidence of late-onset MG (p < 0.05), and a decrease in early onset MG were detected (p < 0.01). These findings were related to nonthymoma MG. The median age at onset of the disease steadily increased over time. A changing pattern of MG incidence with an increase in frequency of late-onset and a decrease of early onset MG was found in the last years, giving a significant shift to older age at onset of the disease. Unknown environmental factors may have driven this change in MG epidemiology.


Myasthenia gravis Epidemiology Incidence 



This work was supported by grants from the Italian Ministry of University and from Fondazione Cassa di Risparmio di Ferrara.

Conflict of interest statement

The authors declare that they have no conflicts of interest.


  1. 1.
    McGrogan A, Sneddon S, de Vries CS (2010) The incidence of myasthenia gravis: a systematic literature review. Neuroepidemiology 34:171–183CrossRefPubMedGoogle Scholar
  2. 2.
    Phillips LH 2nd, Tomer JC, Anderson MS, Cox GM (1992) The epidemiology of myasthenia gravis in central and western Virginia. Neurology 42:1888–1893PubMedGoogle Scholar
  3. 3.
    Aragones JM, Bolibar I, Bonfill X, Bufill E, Mummany A, Alonso F, Illa I (2003) Myasthenia gravis. A higher-than-expected incidence in the elderly. Neurology 60:1024–1026CrossRefPubMedGoogle Scholar
  4. 4.
    Somnier FE (2005) Increasing incidence of late-onset anti-AChR antibody-seropositive myasthenia gravis. Neurology 65:928–930CrossRefPubMedGoogle Scholar
  5. 5.
    Matsui N, Nakane S, Nakagawa Y, Kondo K, Mitsui T, Matsumoto T, Arisaswa K, Kaji R (2009) Increasing incidence of elderly onset patients with myasthenia gravis in a local area of Japan. J Neurol Neurosurg Psychiatry 80:1168–1171CrossRefPubMedGoogle Scholar
  6. 6.
    Aarli JA (2008) Myasthenia gravis in the elderly. Is it different? Ann N Y Acad Sci 1132:238–243CrossRefPubMedGoogle Scholar
  7. 7.
    Vincent A, Clover L, Buckley C, Grimley Evans J, Rothwell PM, the UK myasthenia gravis survey (2003) Evidence of underdiagnosis of myasthenia gravis in older people. J Neurol Neurosurg Psychiatry 74:1105–1108CrossRefPubMedGoogle Scholar
  8. 8.
    Task Force of the Medical Scientific Advisory Board of the Myasthenia Gravis Foundation of America. Myasthenia Gravis (2000) Recommendation for clinical research standards. Neurology 55:16–23Google Scholar
  9. 9.
    Somnier FE, Keiding N, Paulson OB (1991) Epidemiology of Myasthenia Gravis in Denmark. A longitudinal and comprehensive population survey. Arch Neurol 48:733–739PubMedGoogle Scholar
  10. 10.
    Aarli JA (1999) Late-onset myasthenia gravis: a changing scene. Arch Neurol 56:25–27CrossRefPubMedGoogle Scholar
  11. 11.
    Robertson NP, Deans J, Compston DAS (1998) Myasthenia gravis: a population based epidemiological study in Cambridgeshire England. J Neurol Neurosurg Psychiatry 65:492–496CrossRefPubMedGoogle Scholar
  12. 12.
    Poulas K, Tsibri E, Kokla A, Papanastasiou D, Tsouloufis T, Marinou M, Tsantili P, Papapetropoulos T, Tzartos SJ (2001) Epidemiology of myasthenia gravis in Greece. J Neurol Neurosurg Psychiatry 71:352–356CrossRefPubMedGoogle Scholar
  13. 13.
    Heldal AT, Owe JF, Gilhus NE, Romi F (2009) Seropositive myasthenia gravis: a nationwide epidemiologic study. Neurology 73:150–151CrossRefPubMedGoogle Scholar
  14. 14.
    Emilia-Romagna Study Group on Clinical, Epidemiological Problems in Neurology (1998) Incidence of myasthenia gravis in the Emilia-Romagna region: a prospective multicenter study. Neurology 51:255–258Google Scholar
  15. 15.
    Casetta I, Fallica E, Govoni V, Azzini C, Tola M, Granieri E (2004) Incidence of myasthenia gravis in the province of Ferrara. A community-based study. Neuroepidemiology 23:281–284CrossRefGoogle Scholar
  16. 16.
    Compston DA, Vincent A, Newsom-Davis J, Batchelor JR (1980) Clinical, pathological, HLA antigen and immunological evidence for disease heterogeneity in myasthenia gravis. Brain 103:579–601CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • I. Casetta
    • 1
    Email author
  • E. Groppo
    • 1
  • R. De Gennaro
    • 1
  • E. Cesnik
    • 1
  • L. Piccolo
    • 1
  • S. Volpato
    • 2
  • E. Granieri
    • 1
  1. 1.Section of Clinical Neurology, Department of Medical and Surgical Sciences of Communication and Behavior, Neuroscience CenterUniversity of FerraraFerraraItaly
  2. 2.Section of Internal Medicine, Gerontology and Geriatric, Department of Clinical and Experimental MedicineUniversity of FerraraFerraraItaly

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