Management of focal dystonia of the extensor hallucis longus muscle with botulinum toxin injection: a case report.

Recently botulinum toxin has been used with increasing frequency as a safe and effective treatment for many previously refractory conditions associated with excessive muscle activity. The indications for use of botulinum toxin injection continue to expand. This report describes the case of an 83-year-old woman with a history of diabetes mellitus and lumbar spinal stenosis who developed a severe focal dystonia of the left great toe, such that the toe maintained the extended position. Functionally, the resultant deformity prevented the patient from wearing shoes. In addition, the patient had significant pain in the left great toe. Under needle electromyographic localization, 50 units of botulinum toxin were injected into the left extensor hallucis longus muscle. Two weeks after the injection the patient was symptom free and could place her left foot into a shoe. Seven months later, she remained symptom free. This case illustrates that localized injection of botulinum toxin to a specific lower limb muscle can effectively result in decreased muscle activity and functional improvement.