Botulinum toxin A and musculoskeletal pain]

INTRODUCTION: Relaxant muscle properties and pain relieve effectiveness in neurological spasmodic disorders of botulinum toxin A (BTXA) suggested its relevance to relieve musculoskeletal pain. The aim of this article was to collect literature data and to assess the different analgesia indications of BTXA proposed in the treatment of musculoskeletal pains. METHOD: The international literature was carried out with the Medline data bank using keywords toxin and pain. Only clinical trials have been analysed. RESULTS: Three hundred and seventeen articles were collected and 12 clinical trials were retained. They are focused on 4 chronic diseases, neck pain, tennis elbow, Piriformis syndrome and low back pain. Results of the 6 chronic neck pain studies are contradictory and emphasize the difficulty to display a satisfactory analgesia effect of BTXA in this indication. Results of the studies concerning other indications (tennis elbow, Piriformis syndrome and low back pain) seem to be more effective and clinically pertinent. DISCUSSION: Analgesia BTXA effect seems to be conditioned by the presence of an objective muscular spasm or stringy disease inducing musculoskeletal pain. CONCLUSION: The first data concerning use of BTXA to treat musculoskeletal pains are few and are worth specifying by other studies.     

卡马西平、氯硝安定与A型肉毒杆菌毒素治疗面肌、眼睑痉挛疗效对比分析

目的寻求面肌痉挛及眼睑痉挛的有效治疗方法 .方法局部肌肉注射A型肉毒杆菌毒素治疗面肌痉挛及眼睑痉挛47例,随访观察9～26周.结果药效作用时间分别为:面肌痉挛(16.6±4.2)周,眼睑痉挛(9.2±3.8)周.无全身反应,局部副作用轻微,可逆.结论 A型肉毒杆菌毒素治疗法安全、有效、简便,可作为治疗面肌痉挛、眼睑痉挛的一种方法.     

Botulinum toxin A for the treatment of chronic neck pain.

A clinical study tested the therapeutic efficacy of Botulinum toxin A (BTXA) when injected into symptomatic neck muscles after one injection session. Patients with chronic neck pain were randomly assigned to receive either a high dose of an active treatment or an injection of the same volume of normal saline. Patients were compared for 4 months using a comprehensive set of outcome measures that included the Neck Pain and Disability Scale (Spine 24 (1999) 1290) and pressure algometry (Arch Phys Med Rehabil 67 (1986) 406; Pain 30 (1987) 115; Clin J Pain 2 (1987) 207). Analyses were consistent in showing significant benefits from the injection session; however, the effects were not specific to the group treated with BTXA. Both treatment and control groups showed a significant decline in pain and disability across time and an increased ability to withstand pressure on trigger points. The heavy incidence of adverse events in the treatment group may partly explain the absence of a treatment effect specific to BTXA. The results show that a single dose treatment without physical therapy is not effective for chronic neck pain.     

Botulinum toxin therapy for myofascial pain disorders

Myofascial pain disorder can originate from various muscles in the body. Numerous therapeutic approaches have been used to treat myofascial pain syndrome with varying success. Botulinum toxin neurolysis may become an important treatment regimen because it sustains relaxation of muscles. There is a growing body of clinical evidence for the efficacy of botulinum toxin in the treatment of painful myofascial conditions. The conditions that have been investigated include chronic low back pain, chronic cervical-associated headache, myofascial pain, myofascial pain syndrome and pain from chronic muscle spasm, and refractory myofascial pain. One of these studies was an open-label, exploratory pilot study into the cervicothoracic and lumbosacral regions using a novel injection technique.     

Botulinum toxin in specific pain therapy

Botulinum toxin has been used for therapeutic purposes in medicine for more than 20 years. Its effective use now covers more than 50 conditions in a wide variety of areas. Its medicinal use was initially based on its blockade of neuromuscular and neurosecretory transfers. Its use for conditions in the field of specific pain therapy is currently authorized in Germany for spastic torticollis, blepharospasm, hemifacial spasm, spastic equine gait in cases of idiopathic cerebral paresis, and spasticity of the arm following stroke.New publications suggest that it can usefully be employed for numerous other painful conditions.The modes of action known today are not confined to the blockade of cholinergic innervation.Indeed, there is also evidence that therapeutic effects are mediated through a normalization of muscle spindle activity, retrograde intake into the CNS with modulation of the central neuropeptide function, inhibition of sterile neurogenic inflammation, and normalization of endplate dysfunction. In view of the methodological peculiarities of studies in the field of pain therapy, such as injection techniques, injection sites, blind study techniques, dosage etc., the scientific evidence for its use in a wide variety of pain syndromes is still patchy in many areas.For this reason the use of botulinum toxin for these syndromes is only justified after full use has been made of standard therapeutic methods and evaluation in specialized centers.The possibility of considering botulinum toxin in specific pain therapy contexts is a new option for patients and doctors.However, its use calls for detailed knowledge of functional neuroanatomy and extensive practical experience and expertise.     

Botulinum toxin type B: An effective treatment for alleviating pain associated with cervical dystonia

Neck pain is reported in 75% is strongly associated with greater disability and decreased quality of life. Botulinum toxin type B (BoNT-B; Myobloc?) is a new botulinum toxin that has been proven safe and effective in reducing the pain, severity, and disability of patients with cervical dystonia. We analyzed a subset of efficacy data from two randomized, double blind, placebo-controlled clinical trials. The first study consisted of three treatment groups in patients who were responders to the type A toxin, including placebo (n=36), 5000 units (U) (n=36), 10,000 U (n=37). The second study consisted of placebo (n=38) and 10,000-U treatment groups (n=39) in patients not responding to the type A toxin. For this analysis, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-subscale scores for pain and three visual analog scales (Patient Analog Pain, Patient Global, and Principal Investigator Global Assessments) were evaluated. A dose-response effect was observed in the reduction of pain based on the TWSTRS-subscale scores. In both studies, mean improvements from baseline to week 4 for all patients were significant compared with placebo (P<0.005). BoNT-B also significantly improved mean values for all VAS assessments. Our analysis confirms that BoNT-B significantly reduces the pain associated with cervical dystonia and improves patients' overall condition. This clinical benefit suggests that BoNT-B may be useful in other pain syndromes involving involuntary muscle spasms or contractions.     

Botulinum toxin injections for the treatment of frontal tension headache

Abstract We performed a randomized, double-blind, placebo-controlled trial to determine the efficacy of botulinum toxin type A (BOTOX; Allergan) in treating frontal tension-type headache (TTH). A total of 40 patients attending a headache treatment center were randomized to receive 50 U botulinum toxin type A or saline, injected at 10 sites of the forehead. Frequency and severity of headaches before and after injection were compared. The intensity of headaches in the botulinum toxin type A group, but not the placebo group, fell significantly from an average score of 5.19 to 4.65 (p<0.0001). Botulinum toxin type A patients and placebo patients experienced an average reduction in the number of headaches per month, but these reductions were not significantly different between groups. Botulinum toxin type A was well tolerated, with no significant adverse events. Botulinum toxin type A injections in the management of frontal TTH has been shown by this study to be both effective and well tolerated. It should be noted that the effect of botulinum toxin on intensity of headache, although statistically significant, was relatively small.     

Botulinum toxin in the treatment of focal hyperhidrosis

INTRODUCTION: Botulinum A toxin (BTX-A) acts primarily at peripheral cholinergic synapses, inhibiting the release of acetylcholine. Initially it has been used to block the neuromuscular junction in focal dystonic and spastic syndromes. Recently there has been suggestions for potential clinical indications in non-muscular diseases where cholinergic terminals play a role. GUSTATORY SWEATING: In 1995 physicians reported a long-lasting anhidrotic effect of intracutaneous BTX-A injections in patients suffering from gustatory sweating (Frey's syndrome). Consequently, a number of clinical studies demonstrated good efficacy of intradermal injections of botulinumtoxin in patients with focal hyperhidrosis. FOCAL HYPERHIDROSIS OF THE PALMS AND AXILLAE: Focal hyperhidrosis is usually confined to the palms and axillae. Excessive sweating may be a social handicap and an occupational hazard. The management of focal hyperhidrosis remains controversial. Topical antiperspirants are only effective in very mild cases. Iontophoresis with tap water or anticholinergic drugs is messy and time consuming with only short-lived effect. Sympathectomy, the cornerstone of surgical management, is usually effective in palmar hyperhidrosis. Complications of this technique include surgical risks, postoperative and cosmetic problems and compensatory hyperhidrosis. AXILLARY HYPERHIDROSIS: Several studies confirmed that intracutaneous injections of botulinum toxin are useful in the majority of patients with axillary hyperhidrosis resistant to conventional treatment. In axillary hyperhidrosis total doses are ranging from 200-400 mU Dysport or from 80 to 130 mU Botox to reach a good clinical response. Injections are usually well tolerated and no serious side-effects have been observed. The mean duration of anhidrotic effect ranges between 3 and 9 weeks. PALMAR HYPERHIDROSIS: The use of botulinumtoxin in patients with palmar hyperhidrosis is rather difficult. The therapeutic window is smaller because injections are complicated by transient weakness of the small hand-muscles. Furthermore the injections at the palms are painful which can be overcomed by application of local anaesthetics or the blockade of the ulnar and median nerves. The duration of anhidrotic effect ranges from 20 to 50 weeks. CONCLUSION: Intracutaneous injections of botulinum-toxin should be offered to patients with focal hyperhidrosis of the palms and axillae causing serious social, psychologic and occupational problems, resistant to other conventional treatment options.     

A comparative trial of botulinum toxin type A and methylprednisolone for the treatment of myofascial pain syndrome and pain from chronic muscle spasm

Myofascial pain syndrome (MPS) is a common illness, characterised by acute or chronic focal pain, muscle stiffness and fatigue. The pathophysiology of MPS remains unclear. Previous preliminary studies have demonstrated therapeutic efficacy of the muscle relaxant botulinum toxin type A (BTX-A) in the treatment of MPS. A single-centre, randomised trial compared the effects of BTX-A with the steroid methylprednisolone (both administered intramuscularly with 0.5% bupivacaine), in 40 patients suffering from chronic myofascial pain in the piriformis, iliopsoas or scalenus anterior muscles. Thirty days after receiving an injection of either BTX-A or steroid followed by post-injection physiotherapy, pain severity had decreased significantly from baseline in both treatment groups, with no significant difference between the two treatment groups. However, the baseline pain score was significantly higher in the BTX-A treatment group compared with the steroid group (7.9 vs. 7.3), and the reduction in pain score between baseline and 30 days post-injection was greater in the BTX-A group compared with the steroid group (-3.9 vs. -3.5; P=0.06). At 60 days post-injection, the pain severity score for the BTX-A-treated patients was statistically significantly lower than the pain score for the steroid-treated population (2.3 vs. 4.9). Furthermore, the reduction in pain score in the BTX-A group at 60 days post-injection was greater than at 30 days (-5.5 vs. -3.9), whereas the effect of the steroid had begun to wane. These results indicate the superior efficacy of BTX-A over conventional steroid treatment in patients suffering from MPS, when combined with appropriate physiotherapy.     

Botulinum toxin treatment of axial and cervical dystonia

Axial truncal dystonia is characterized by an abnormal trunk posture often superimposed by myoclonic motor activities. Cervical dystonia is a motor syndrome characterized by abnormal head and neck posture due to tonic involuntary contractions in a certain set of muscles often superimposed by myoclonic or tremolous movements. Intramuscular injection of botulinum toxin is the first line treatment in cervical dystonia, in axial truncal dystonias botulinum toxin therapy is used only in mild forms. In this review the theoretical background, practical aspects and efficacy results especially in cervical dystonia are presented. Treatment of axial trunk dystonia is only briefly discussed at the beginning of this review.     

Botulinum toxin treatment of axial and cervical dystonia

Axial truncal dystonia is characterized by an abnormal trunk posture often superimposed by myoclonic motor activities. Cervical dystonia is a motor syndrome characterized by abnormal head and neck posture due to tonic involuntary contractions in a certain set of muscles often superimposed by myoclonic or tremulous movements. Intramuscular injection of botulinum toxin is the first line treatment in cervical dystonia, in axial truncal dystonias botulinum toxin therapy is used only in mild forms. In this review the theoretical background, practical aspects and efficacy results especially in cervical dystonia are presented. Treatment of axial trunk dystonia is only briefly discussed at the beginning of this review.     

Anti-inflammatory agents for the treatment of musculoskeletal pain and arthritis

Pain produced by musculoskeletal disorders commonly misconceived as having mechanical etiology often is caused by inflammatory mechanisms. Simple analgesics (ie, those that lack anti-inflammatory action) often are used to treat musculoskeletal pain when an anti-inflammatory analgesic may be more effective for the painful condition. This review addresses the anti-inflammatory agents available for the symptomatic management of common inflammatory musculoskeletal conditions including osteoarthritis, rheumatoid arthritis, and low back pain.