Iverson's Disease is a chronic and progressive muscular disorder that affects Humans. It causes fatal degeneration of motor skills, but does not impair mental faculties. There is no known cure and no known case of remission. The disease bears a number of similarities to Motor neurone disease.
In 2359, Admiral Mark Jameson was diagnosed with this illness. Jameson attempted to alleviate the symptoms by using a alien drug from Cerberus II to reverse the aging process. While this appeared successful, Jameson's overuse of the drug eventually killed him. (TNG: "Too Short a Season")