Experimental Confirmation by Sir Victor Horsley of the Relationship Between Thyroid Gland Dysfunction and Myxedema

Whereas Sir Victor Horsley is well known for his many contributions to neurosurgery, this is not the case for his treatments for both myxedema and cretinism. Horsley's research on thyroid physiology was concentrated in the years 1884–1890, while he was director of the Brown Institute for Animals. Based upon experimentation with dogs and monkeys as well as some human patients, Horsley demonstrated conclusively that removal of the thyroid gland produced tremors, rigidity, and paralysis, which he attributed to changes in lower motor centers. Furthermore, the development of imbecility suggested that thyroid excision produced deficits in higher cortical functioning. Horsley showed that it was possible to alleviate temporarily some of the psychological and physiological symptoms of both myxedema and cretinism using transplanted thyroid tissue. Several of Horsley's students, most notably George Murray, continued and extended his work by examining other ways in which myxedema and cretinism could be treated (e.g., by injecting an extract of thyroid tissue).