TREATMENT OF MYASTHENIA GRAVIS BY OVULATORY SUPPRESSION.

Introduction Young myasthenic women manifest fluctuations in strength through various phases of the menstrual cycle. Typically, there is an exacerbation of weakness in the preovulatory stage, specifically in the five to seven days preceding the onset of menses, with a more accentuated depression of strength in the immediate premenstruum, often requiring increased doses of anticholinesterase drugs. 1 As menstrual flow is initiated, gradual recovery ensues and is maintained through and beyond the next ovulation. In a recent communication, 2 such variation has been linked to alterations in electrolyte balance due to the influence of progestational and mineralocorticoid hormones upon ionic flux across cell membranes. Experimentally, in myasthenic patients, the administration of progesterone intramuscularly was initially marked by a natriuresis without change in muscular strength. The sodium loss was then followed by sodium retention and an increased urinary excretion of aldosterone, the potent sodium-retaining hormone, which persisted after progesterone withdrawal; both