SINCE the use of scopolamine by Gnauck1 in 1882 in cases of paralysis agitans, an unknown number of chemotherapies have been studied.2 None has been effective in arresting or reversing the course of the disorder. At best, a few have been considered relatively effective in relieving some of the more distressing symptoms in some patients. Walshe3 stated that no one drug or combination of drugs has established its supremacy over the others.
In 1949 Doshay and Constable4 reported their experience with the use of trihexyphenidyl (artane®) in a series of 117 patients. They found it to be more effective than atropine or belladonna derivatives in producing what they labeled "favorable results" in patients suffering from paralysis agitans. Their findings were confirmed by Corbin.5 Other clinical studies6 have confirmed the conclusion that trihexyphenidyl has merits in the armamentarium of treatment of paralysis agitans. There