Long-term outcome in patients with myasthenia gravis: one decade longitudinal study

Introduction: Even treated, myasthenia gravis (MG) continues to represent a significant burden and might continuously affect patients' quality of life (QoL). The aim of our longitudinal study was to analyze QoL in a large cohort of MG patients after a 10-year follow-up period.

Methods: This study comprised 78 MG patients (60% females, 50 ± 16 years old at baseline, 70% AchR positive) who were retested after 10 years. Disease severity was evaluated by MGFA classification. QoL was assessed using SF-36 questionnaire and Myasthenia Gravis-specific Questionnaire (MGQ). Hamilton rating scales for depression and anxiety (HDRS and HARS), Multidimensional Scale of Perceived Social Support (MSPSS) and Acceptance of Illness Scale (AIS) were also used.

Results: Similar percentage of patients was in remission at both time points (42% and 45%). However, at baseline all patients were treated, while 32% were treatment-free at follow-up. SF-36, MGQ, MSPSS and AIS scores were similar at baseline and retest. Mean HDRS and HARS scores worsened during time (p < 0.05), although percentage of patients with depression and anxiety did not change significantly. Significant predictors of worse SF-36 score at retest were depression (β = - 0.45, p < 0.01), poor disease acceptance (β = - 0.44, p < 0.01) and older age (β = - 0.30, p < 0.01). Significant predictors of worse MGQ score at retest were poor disease acceptance (β = - 0.40, p < 0.01), retirement (β = - 0.36, p < 0.01), lower education (β = 0.25, p < 0.01), and depression (β = - 0.18, p < 0.05).

Conclusions: Although after 10 years, a significant number of MG patients were in remission, their QoL was still reduced. Neurologists should be aware that patients' perception of poor QoL may persist even if MG is well treated from a physician's perspective.