Botulinum toxins in the treatment of dystonia

Abstract

In the 1820s, a German physician, Justinus Kerner, reported his clinical experience with 230 patients who developed weakness, gastrointestinal disturbances, dry eyes, and dry skin associated with the ingestion of contaminated meat. This condition, termed by Kerner as “sausage poison,” was later named “botulism,” from the Latin term botulus or sausage (1). A century later, Edward Schantz first cultured Clostridium botulinum and isolated the toxin. In 1973, Alan Scott first used botulinum toxin type A (BoTN-A) in monkey experiments, and in 1980 he was able to first test this drug in humans (2). This work led to therapeutic trials in dystonia by a number of investigators, culminating with U.S. approval of Oculinum1/Botox1 for the treatment of strabismus, blepharospasm, and hemifacial spasm in December 1989. An indication for approval for treatment of cervical dystonia (CD) was given in 2000. Dysport1, another BoTN-A, developed in Europe received approvals outside the United States in a similar time frame. MyoblocTM, a BoTN-B therapy, was approved in the United States for the treatment of CD in 2000; this agent is also approved for usage in Europe under the trade name Neurobloc1 (Table 1) (3).