Kamanli A et al. (2005) Comparison of lidocaine injection, botulinum toxin injection, and dry needling to trigger points in myofascial pain syndrome. Rheumatol Int 25: 604–611

Myofascial pain syndrome (MPS) is usually treated by either dry needling or injections of anesthetic into hypersensitive 'trigger points'. Both techniques show similar therapeutic efficacy. Controversially, injections of botulinum toxin type A (BTX) into trigger points have also been used to treat MPS. A prospective, single-blind study carried out in Turkey aimed to compare the efficacy of BTX injection with dry needling and with lidocaine injection.

In total, 23 female and 6 male MPS patients were randomized to one of three treatment arms: lidocaine injection (n = 10, 32 trigger points); dry needling (n = 10, 33 trigger points); or BTX injection (n = 9, 22 trigger points). Pressure-pain thresholds at trigger points were compared with those of the unaffected area on the contralateral side, before and after treatment. In all patients, muscles at the injection sites were lengthened by passive stretching after treatment. After 1 month, all three treatments had significantly improved patients' cervical range of motion and pressure-pain thresholds at trigger points, but pain, fatigue and work disability decreased only in the BTX and lidocaine arms, with lidocaine showing the greatest effect. Statistically significant improvements in depression and anxiety scores were seen only with BTX (P <0.05).

Lidocaine injection should be recommended rather than dry needling, say the authors, because of its rapid effect on MPS trigger points and low incidence of injection-site pain. BTX is a higher-cost option that should be reserved for patients who do not respond to conventional treatments.