In Season one, episode 13, "Cursed", House figures out that the father of his young patient was misdiagnosed with Carpal Tunnel Syndrome and says that damage to the ulnar nerve from leprosy would have been misdiagnosed as CTS. The problem is, damage to the ulnar nerve wouldn't present as CTS, damage to the MEDIAN nerve would. The ulnar nerve doesn't pass through the carpal tunnel (it passes over it) and it serves as the nerve supply for different areas than the median nerve, therefore would present with numbness in different areas. Looks like the medical staff that reviews the scripts missed that one!