BOTULINUM TOXIN TYPE A (BOTOX®) IN THE TREATMENT OF REFRACTORY MYOFASCIAL CERVICOTHORACIC PAIN: A PROSPECTIVE TRIAL

Dorene Taqi, Ian Gunyea, PA‐C, Bhadresh Bhakta, MD, Venkatesh Movva, MD, Sameh Ward, MD, Mike Jenson, PA‐C, CPP, Mike Royal, MD Pain Evaluation and Treatment Center, 5801 East 41 st Street, Suite 1000, Tulsa, OK 74135 (918) 622‐3888; fax: (918) 828‐9050; email: royal@tulsapain.com Myofascial pain syndrome (MPS) is a common chronic pain syndrome defined by the presence of trigger points and referred pain (Travell, Simons, 1983). A prospective study of patients with MPS involving the upper trapezius and levator scapulae muscles refractory to conservative therapy was performed to evaluate the effects of volume of diluent used with Botulinum toxin Type A (BT A , Botox®, Allergan, Inc., Irvine, CA). A total of 90 patients are planned in this double‐blind, prospective trial, however only 45 have completed the 24 week observation period. We have not broken the blind, but wish to report interim prospective data on responses to BT A . All patients who entered had only short‐term responses to trigger point injections and were randomized to three volume groups (200u/cc, 100u/cc and 50u/cc in saline). Algometry, tenderness, spasm scores, VAS scores, McGill short form pain questionnaire scores, and global responses were followed at 2, 4, 6, 8, 12, and 24 weeks. The injections were performed as trigger point injections by palpation directly into the trigger point with 25u/site. The total patient dose was 75–150 units for 3–6 trigger points into the affected muscles. Global responses were graded on a 4‐ to 4+ scale. Pressure algometry was performed in the standard fashion. Muscle spasm and tenderness was graded on a 4 point scale. Of the 45 patients, 33 were responders with at least a 1+ subjective response and 23/45 showed at least a 3+ response lasting for 24 weeks. Algometry scores nearly doubled in this group and significant drops in McGill, tenderness, spasm and VAS scores were seen as well. The injections were well tolerated with no significant side effects noted. Botulinum toxin injection appears to be a promising method for managing refractory MPS. Travell JG, Simons DG. Myofascial pain and dysfunction: the trigger point manual. Vol. I. Baltimore, MD: Williams & Wilkins; 1983.