Human Response to Unintended Intrathecal Injection of Botulinum Toxin


Ian Carroll, MD, MS, Anesthesia and Pain Management, Stanford University, 780 Welch Road, Suite 208F, Palo Alto, CA 94040, USA. Tel: 650-380-5915; Fax: 650-725-9642; E-mail:


Objective.  Describe the first reported human intrathecal (IT) botulinum toxin injection.

Design.  Case report.

Setting and Patients.  We report here the sequelae to an unintended IT injection of botulinum toxin type B (BTB) in a 60-year-old woman with chronic back pain.

Results.  Following the IT administration of BTB, the patient experienced the onset of symmetric ascending stocking distribution painful dysesthesias, which persisted for approximately 6 months before receding. Objective neurologic deficits were not appreciated, and analgesic effects were prominently absent.

Conclusions.  Analgesic actions of botulinum toxins in animals and in humans have led to speculation that IT botulinum toxin might exert significant analgesic effects. The unusual and unexpected subsequent clinical course, neurologic sequelae, dysesthesias, and absence of analgesia suggest that botulinum toxin will not be a therapeutic modality to treat pain as proposed by those studying botulinum toxin in animal models.