Hyperthyroidism

Background
Its was a disease, of humans that the thyroid gland - which control - chemical reactions in the body goes haywire, speeding up a whole different type of bodily functions, in humans a cure was found one hundred and fifty years ago. In Vulcan never found a cure, they never had this happen. The being from Alpha Octavius Four, that injected the poison in Spock acted like this.