Surrogate therapeutic outcome measures in patients with myasthenia gravis.
Treatment of acquired myasthenia gravis (MG) with immunotherapies successfully relieves symptoms and improves strength as documented by the Quantitative Myasthenia Gravis Score for disease severity (QMGS). Neuromuscular function, as demonstrated by the surrogate measures of repetitive nerve stimulation (RNS) and single-fiber electromyography (SFEMG), is sensitive for diagnosis and staging disease severity. This study of 51 patients treated with immunomodulation confirmed that RNS and SFEMG are useful to stage disease severity, but found that clinical measures such as the QMGS are more sensitive to change than electrophysiological parameters. The presence of blocking on SFEMG did predict responsiveness to intravenous immunoglobulin (IVIG) treatment, providing clinicians with an objective, reliable, quantitative measure to help determine which patients will benefit from this costly treatment.
Zinman
Lorne
L
Sunnybrook Health Sciences Centre, Toronto, Canada.
Baryshnik
Devra
D
Bril
Vera
V
D000328:Adult; D004311:Double-Blind Method; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000187:drug effects* / Q000502:physiology; D009157:Myasthenia Gravis / Q000503:physiopathology* / Q000628:therapy*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D016756:Immunoglobulins, Intravenous