Eighty-four cases have been reported in the literature in which hyperthyroidism and myasthenia gravis have existed together. Weickhardt and Redmond have reviewed these cases and report 29 deaths in this group, showing the serious prognosis that exists when this relationship occurs—the prognosis appearing to be most grave when the hyperthyroidism develops in a patient with preexisting myasthenia gravis. The fact that, within the course of a few months in 1960, we were acquainted with 3 additional such cases has prompted this report. It has been well established that, when these 2 diseases coexist, control of the hyperthyroidism is the essential therapeutic problem, and we would like to suggest that perhaps such control may be more safely induced by the use of I,131 along with control of the myasthenia gravis, than by subtotal thyroidectomy.
Since the 2 diseases have so many findings common to both, the diagnosis of myasthenia gravis