Phase 1 for Complex Regional Pain Syndrome

Objective: The primary aim is to evaluate the efficacy of botulinum toxin A in reducing overall limb pain in patients with complex regional pain syndrome (CRPS). Additionally the investigators would like to see if quality of life is improved and disability scores decreased. Research Design: This is a double blinded, randomized cross-over study that will be conducted over a 7 month period. It is a pilot study that will include twenty subjects recruited from the Neurology CRPS clinic at VA Connecticut and from outside VA hospitals within a 150 mile radius. Subjects will receive an intramuscular injection Treatment A which is only 1% lidocaine or Treatment B which is mixture of botulinum toxin A + 1% lidocaine in the affected limb only. This is a cross over study where patients will receive Treatment A or B initially during the first of four study visits and during the third study visit while receive whichever treatment not given during the first visit. Dr. Sameer Ali, VA neurology fellow, will be blinded when administering the treatments. Dr. Hajime Tokuno, VA neurologist who is the principal investigator of the trial will prepare the treatments. Clinical pharmacy will be randomizing the treatments. Dr. Tokuno will not be blinded as he needs to know which treatment has been given in case of complications. Impact/Significance: The significance of this study is the possible discovery of a new, safer, less invasive, and more efficacious therapeutic option for patients suffering from CRPS. Currently medical management with neuropathic pain meds, interventions such as sympathetic nerve blocks and ketamine infusion has helped some patients and not others. The investigators are trying to see whether either of the two treatments and especially the treatment with botulinum toxin may be a more viable alternative than existing modalities.