BOTOX and Physical Therapy in the Treatment of Piriformis Syndrome

Abstract

Injection with botulinum toxin A is an effective adjunct to physical therapy in the treatment of piriformis syndrome. H-reflex prolongation by flexion, adduction, and internal rotation (FAIR test) beyond 1.86 msec (3 SD) of the mean is a clinical indication of piriformis syndrome.

Brief review: Piriformis syndrome: etiology, diagnosis, and management

“…Notwithstanding the lack of critical evaluation, the use of physical therapy methods are well supported in the literature. 4,5,7,[19][20][21]40,41,43,64,73,90 In general, physical therapy is performed only as part of multimodal therapy. Since PM injection is the main reason for the referral of this group of patients to an anesthesiologist/pain specialist, most of the discussion will focus on the technique.…”

“…Botulinum toxin injections in PS 14,21,29,35,48,84,87,90,[102][103][104] Botulinum toxin type A is one of seven immunologically distinct serotypes (A-G) of neurotoxin produced by Clostridium botulinum. Botulinum toxin type A can be administered with fluoroscopic, electromyelographic, CT, or MRI guidance.…”

“…The recommended dose of botulinum toxin type A in PS is usually 100-200 units diluted in small volumes (1-1.5 mL) of normal saline. 2,14,21,35,102 In summary, the indications, techniques, dosages, and monitoring vary significantly. This variability limits any comparison of studies and treatment groups.…”

The effects of botulinum toxin A on mechanical and cold allodynia in a rat model of neuropathic pain

“…The analgesic action of BoNT-A has long been considered to be an effect of muscle relaxation. [2][3][4] Indeed, abnormal muscle contraction often causes pain in pathological conditions, and inhibition of muscle contraction would be an obvious reason for pain reduction. However, considering the dissociation between observed periods of muscle weakness and pain relief in this neuropathic pain model, it is unlikely that the anti-allodynic action of BoNT-A was due to muscle relaxation.…”

“…1 In addition, BoNT-A has been shown to relieve the pain induced by myofascial pain syndrome, chronic muscle spasm, low back pain and piriformis syndrome. [2][3][4] Although the analgesic effect of BoNT-A has long been considered secondary to its action for muscle relaxation, BoNT-A also affects the release of the neurotransmitters that are involved in pain perception. 5,6 BoNT-A has recently been shown to have an analgesic effect on the pain induced by formalin and capsaicin, and on chronic facial pain.…”