Course and prognosis of myasthenia gravis: a systematic review

Abstract

The clinical course of myasthenia gravis (MG) is variable, and spontaneous remission is still uncommon. Knowledge of the prognostic factors may help understand the course of MG and thus optimize its management. A systematic review search was conducted in MEDLINE and EMBASE for English language studies from 1985 through 2009. We identified additional studies by reviewing bibliographies of retrieved articles and hand search main journal of neurology. Studies evaluating variables associated with or predictive of remission in adult patients with MG were included. Because of methodological heterogeneity, we refrained from statistical pooling, instead, a best evidence synthesis was used for summarizing the results. From 1810 potentially relevant studies, 13 cohort studies met the inclusion criteria. The included studies were heterogeneous considerably in sample size, disease duration, follow-up years, definition of remission, and analysis. Study quality was limited by retrospective design in most studies and lack of multivariate analysis. Time of diagnosis from onset (<1 year) showed strong evidence of predicting a better remission. In studies using completely stable remission outcomes, there was strong evidence that age at onset (<40 years) was of prognostic importance. Furthermore, gender showed no association with remission. Time of diagnosis from onset and age at onset were found to be predictors of remission. Gender does not seem to predict the course of MG. Our findings should be interpreted with caution because of the clinical and methodological heterogeneity of included studies.

Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001–2012)

“…Information was lacking about the specific treatment used in 1 of the 5 cats that showed normalization of AChR antibody titer. Spontaneous immune remission is reported to occur in about 88.7% of canine acquired nonthymoma MG cases and clinical remission in 19.2–77.6% of human acquired MG cases 36, 37. Based on the results of this study and previous reports, the overall rate of spontaneous remission appears to be less in cats compared to dogs and humans.…”

Clinical predictors for the prognosis of myasthenia gravis

“…Time of diagnosis after onset and age at onset (<40 years) were found to be predictive factors of remission. Gender seems to be an un-relevant factor for predicting MG [9]. Thymus hyperplasia was more common than other thymus pathologies in relapsed MG [9].…”

“…Gender seems to be an un-relevant factor for predicting MG [9]. Thymus hyperplasia was more common than other thymus pathologies in relapsed MG [9]. However, the prognostic value of thymoma on MG relapse remains inconclusive.…”

Brazilian-Portuguese translation, cross-cultural adaptation and validation of the Myasthenia Gravis Composite scale. A multicentric study

“…The prevalence of MG varies from 1.7 to 21.3 cases per million people per year in the general population, mainly affecting individuals aged 20-40 years, and more women than men (ratio 3:2). The mortality rate varies from 0.06 to 0.89 per million people each year 3,4 . Disease severity depends on the compromised muscle groups, varying from mild, with purely ocular symptoms, to the most serious cases with generalized muscle weakness and respiratory failure 1 .…”