Research article

BMC Neurology

, 10:46

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

A systematic review of population based epidemiological studies in Myasthenia Gravis

  • Aisling S CarrAffiliated withDepartment of Neurology, Royal Victoria Hospital Email author 
  • , Chris R CardwellAffiliated withDepartment of Epidemiology and Medical Statistics, Queens University
  • , Peter O McCarronAffiliated withDepartment of Epidemiology and Medical Statistics, Queens University
  • , John McConvilleAffiliated withDepartment of Neurology, Royal Victoria HospitalDepartment of Neurology, Ulster Hospital



The aim was to collate all myasthenia gravis (MG) epidemiological studies including AChR MG and MuSK MG specific studies. To synthesize data on incidence rate (IR), prevalence rate (PR) and mortality rate (MR) of the condition and investigate the influence of environmental and technical factors on any trends or variation observed.


Studies were identified using multiple sources and meta-analysis performed to calculate pooled estimates for IR, PR and MR.


55 studies performed between 1950 and 2007 were included, representing 1.7 billion population-years. For All MG estimated pooled IR (eIR): 5.3 per million person-years (C.I.:4.4, 6.1), range: 1.7 to 21.3; estimated pooled PR: 77.7 per million persons (C.I.:64.0, 94.3), range 15 to 179; MR range 0.1 to 0.9 per millions person-years. AChR MG eIR: 7.3 (C.I.:5.5, 7.8), range: 4.3 to 18.0; MuSK MG IR range: 0.1 to 0.32. However marked variation persisted between populations studied with similar methodology and in similar areas.


We report marked variation in observed frequencies of MG. We show evidence of increasing frequency of MG with year of study and improved study quality. This probably reflects improved case ascertainment. But other factors must also influence disease onset resulting in the observed variation in IR across geographically and genetically similar populations.