THIS report summarizes the effects of thyroxin therapy as observed in 64 patients presenting clinical evidence of otosclerosis. Of these, 32 patients were treated according to the technic of Gray, while in 32 additional patients a different local anesthetic and a different preparation of thyroxin were employed for purposes of comparison.
The hypothesis that "the essential causative factor of otosclerosis is a gradually increasing defect in the vasomotor mechanism which governs the nutrition of the structures of the organ of hearing as a whole" was advanced by the late Albert A. Gray in 1934.1 In his ingenious and convincing presentation it was pointed out that since the axon reflexes were included in the vasomotor mechanism and since the stimulus exciting the vasomotor mechanism was sound alone, it followed that the vestibular apparatus and the semicircular canals would be unaffected in otosclerosis. The deafness of persons with otosclerosis was regarded as