The Effect of Small Doses of Botulinum Toxin A on Neck-Shoulder Myofascial Pain Syndrome: A Double-Blind, Randomized, and Controlled Crossover Trial.

Ojala T, Arokoski JP, Partanen J.

From the *Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland, and daggerDepartment of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland.

OBJECTIVES:: Myofascial pain syndrome is a common cause of muscular pain in the shoulder-neck region. Injections of large amounts of botulinum toxin A have been found to be beneficial for the alleviation of myofascial pain, but large doses of this toxin may cause paresis of the muscle and other adverse events. The aim of this work was to determine the effect of small doses (5 U) of botulinum toxin A (BTA) injected directly into the painful trigger points of the muscles, using a double-blind crossover technique.

METHODS:: On the basis of the empirical criteria proposed for diagnosis of myofascial pain syndrome, 31 patients suffering from myofascial pain in the neck-shoulder region were studied. The patients received either botulinum toxin A or physiological saline injections on 2 occasions 4 weeks apart. The total dose varied from 15 to 35 U of botulinum toxin A [28 +/- 6 U (mean +/- SD)]. The follow-up measurements were carried out at 4 weeks after each treatment. Neck pain and result of treatment were assessed with questionnaires. The pressure pain threshold was determined using a dolorimeter.

RESULTS:: Neck pain values decreased from 4.3 +/- 2.4 to 3.3 +/- 2.0 after saline injections and from 4.1 +/- 2.1 to 3.3 +/- 2.2 after botulinum toxin A. The pressure pain threshold values increased from 5.2 +/- 1.6 to 5.9 +/- 1.5 and from 5.7 +/- 1.6 to 5.9 +/- 1.6 after injections with saline and botulinum toxin A, respectively. No statistically significant changes in the neck pain and pressure pain threshold values occurred between the botulinum toxin A and saline groups. After the first injections, the subjective result of treatment was significantly (P = 0.008) in favor of botulinum toxin A, and after the second injections, the subjective result was better for saline, but the difference was not statistically significant (P = 0.098). There was no significant difference in the prevalence of side effects between saline and botulinum toxin A.

CONCLUSIONS:: Our study shows that there was no difference between the effect of small doses of botulinum toxin A and those of physiological saline in the treatment of myofascial pain syndrome.

Clin J Pain. 2006 Jan;22(1):90-96.

Botulinum toxin A and B: a comparative dosing study for spasmodic dysphonia.

Blitzer A.

College of Physicians and Surgeons, Columbia University, the New York Center for Voice and Swallowing Disorders, and the New York Center for Clinical Research.

OBJECTIVE: The purpose of this study was to find the conversion factor, safety, and efficacy of type A to type B toxin for laryngeal muscles.

METHODS: Thirty-two patients with adductor spasmodic dysphonia with stable doses of A toxin to manage their symptom were given type B toxin starting at a conversion of 1 U of BTX-A to 50 U of BTX-B. The patients were followed for 1 year, and doses adjusted according to response.

RESULTS: The conversion factor was found to be 52.3 U : 1 U. The onset of action of type B was more rapid (2.09 days vs 3.2 days [P = 0.028]), with a shorter duration of benefit (10.8 weeks vs 17 weeks [P = 0.002). The safety profile for A and B toxin appeared the same, with 3 patients receiving Myobloc reporting dry mouth.

CONCLUSION: This study shows that a conversion factor of 52.3:1 Myobloc (BTX-B) to Botox (BTX-A) and that Myobloc is an effective alternative to Botox (BTX-A) for patients with spasmodic dysphonia. EBM RATING: B-2.

Otolaryngol Head Neck Surg. 2005 Dec;133(6):836-8.

Porta M, Camerlingo M.

Department of Neurology, Headache Center, Policlinico San Marco, Corso Europa 7, Bergamo-Zingonia, Italy, prof.porta@inwind.it.

The authors discuss clinical and international experience about botulinum toxins (BTX types A and B) in headache treatment. Data from literature suggest good results for the treatment of tensiontype headache, migraine and chronic tension-type headache. In the present paper mechanisms of action and injection sites will also be discussed.

J Headache Pain. 2005 Sep;6(4):325-7.

Botulinum toxin A during pregnancy: a survey of treating physicians.

Morgan JC, Iyer SS, Moser ET, Singer C, Sethi KD.

Movement Disorders Program, Department of Neurology, Medical College of Georgia, 1429 Harper Street, HF-1121, Augusta, GA, USA 30912. jmorgan@mcg.edu.

Botulinum toxin A (btxA) is widely used for cosmetic purposes, headaches, dystonia, spasticity, pain and other on and off label uses. Despite the widespread use of btxA in women of childbearing potential, there are few data on the effects of this drug on pregnant women and the fetus. The goal of this study was to survey physicians who use btxA, to determine their experience with pregnant women. We surveyed 900 physicians who used commercially available btxA. The questionnaire asked treating physicians if they had knowingly or unknowingly injected pregnant women and what was the outcome of each pregnancy. In total, 396 physicians (44%) returned questionnaires, of whom only 12 physicians reported injecting pregnant women with btxA. Sixteen pregnant women were injected, mostly in the first trimester, and only one patient, who had prior spontaneous abortions, suffered a miscarriage. Another woman had a therapeutic abortion. All other pregnancies went to term and there were no fetal malformations. Based on this limited survey of treating physicians in the USA, btxA appears to be relatively safe for both expectant mother and fetus. We need further data, however, and we would recommend that physicians and patients carefully consider the risks and benefits before using btxA in pregnant women.

J Neurol Neurosurg Psychiatry. 2006 Jan;77(1):117-9.

The place of botulinum toxin type A in the treatment of focal hyperhidrosis.

Lowe N, Campanati A, Bodokh I, Cliff S, Jaen P, Kreyden O, Naumann M, Offidani A, Vadoud J, Hamm H.

Cranley Clinic, 3 Harcourt House, 19a Cavendish Square, London W1G 0PN, UK. cranleyuk@aol.com

BACKGROUND: Hyperhidrosis (primary or secondary) is excessive sweating beyond that required to return body temperature to normal. It can be localized or generalized, commonly affecting the axillae, palms, soles or face, and can have a substantial negative effect on a patient's quality of life. IMPACT OF DISEASE: Objective evaluation comprising quantitative assessment (gravimetric and Minor's iodine starch test) and subjective evaluation (Dermatology Quality of Life Index and Hyperhidrosis Impact Questionnaire) allow accurate assessment of the impact of hyperhidrosis on patients. BOTULINUM TOXIN TYPE A: Botulinum toxin type A acts by inhibiting the release of acetylcholine at the presynaptic membrane of cholinergic neurones. It has proved useful in treating a number of diseases relating to muscular dystonia and is now proving beneficial in treating hyperhidrosis. Clinical trials investigating botulinum toxin type A use in axillary and palmar hyperhidrosis show significant benefits with few side-effects reported, with a favourable impact also being seen on patient quality of life. Botulinum toxin type A injections are generally well-tolerated with beneficial results lasting from 4 to 16 months. CONCLUSIONS: Botulinum toxin type A injections are an effective and well-tolerated treatment for hyperhidrosis. This paper proposes a positioning of this treatment along with current established treatments, and highlights the role of botulinum toxin type A as a valuable therapy for the treatment of hyperhidrosis.

Br J Dermatol. 2004 Dec;151(6):1115-22.