Role of botulinum toxin type A or B in the complex, multimodality treatment of neck and back pain. Experience on a series of 490 patients

Abstract

Introduction : There are many reports concerning the successful use of Botulinum Toxin (BoNT) for the treatment of myofascial pain and related disorders. Authors report their experience which started as pilot in 1988, in treating chronic neck and back pain due to myofascial pain originating in muscles as anterior scalenus, ileopsoas or superficial muscles as paravertebral and quadratus lomborum usinglocal injections of BoNT. For the procedure it is important to identify the anatomy of muscles. Pain and myofascial syndrome is subacute or chronic. There are trigger points in tight bands of the muscle. Pain is mediated by endorphine, but there is also a component of neurogenic pain. Material and methods : A total series of 490 adults (301 males, 189 females, age 23–79) have been treated during the years 2004–2007 at the Centro Disordini del Movimento e Sindrome di Tourette in Istituto Galeazzi IRCCS, Milan and by one of the authors (MP) at the Pain Center of Policlinico San Marco, Bergamo. A complete anamnestic, clinical and instrumental (CT and MRI, Rx with functional flexion–extension study) evaluation has been conducted in order to rule out structural causes of the syndrome. Echography was also performed in cases in which an abdominal space-occupying lesion had to be excluded. Electromyography was not considered mandatory. Sixty-nine patients were injected at the scalenus complex, 350 at the piriformis and 59 at the ileopsoas muscles, 12 at the quadratus lomborum: 80–150 IU of BoNT (Botox) was injected with a CT-assisted procedure for ileopsoas or piriformis muscles, while EMG monitoring or direct palpation was used for injection into the paravertebral muscles (quadratus lomborum). Clinical picture evolution was documented with a 10-points-based VAS scale, with personal interview with the patient and with a PROLO economic functional evaluation scale. Results : Significant–total relief from pain was documented in 407 (83%) patients, little improvement was documented in 49 (10%), while 34 (7%) patients did not experience any improvement. No side effects were reported. Medical treatment with NSAIDS was routinely performed for 7 days during the postoperative period. Conclusions : The exact etiology of myofascial back pain still has to be determined: BoNT injection provides relief by direct reduction of muscle spasm, interference with the fuse–receptor loop, and impairment of sympathetic transmission. BoNT represents an interesting and safe tool for the management of patients with myofascial pain. A stretching program is mandatory for 6 weeks after the procedure. A well-experienced operator is mandatory when performing this procedure.