Low-dose botulinum toxin type A for the treatment of refractory piriformis syndrome.

Abstract

STUDY OBJECTIVES:

To evaluate the efficacy of a single, low-dose injection of botulinum toxin type A in relieving pain in Korean patients with piriformis syndrome resistant to conventional therapy, and to assess the drug's influence on these patients' quality of life.

DESIGN:

Prospective, single-site, open-label trial.

SETTING:

Rehabilitation medicine clinic in Seoul, Korea.

PATIENTS:

Twenty-nine patients with a confirmed diagnosis of chronic piriformis syndrome and 82 age- and sex-matched healthy subjects were enrolled from April 1, 2003-February 28, 2004. Intervention. In 20 of the patients, botulinum toxin type A 150 U was injected using computed tomographic guidance into the affected unilateral piriformis muscle. The other nine patients served as active controls and received an injection of dexamethasone 5 mg and 1% lidocaine. The healthy subjects did not receive any injection.

MEASUREMENTS AND MAIN RESULTS:

The patients' pain at baseline and at 4, 8, and 12 weeks after treatment was rated by using a numeric rating scale. Health-related quality of life was assessed by using the validated Korean version of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) at baseline and at 4 weeks of treatment. Healthy subjects also completed the SF-36 at baseline. Pain intensity scores were significantly lower at 4, 8, and 12 weeks after treatment than at baseline (p<0.0001). Baseline scores from the SF-36 subscales, including those for physical functioning (p<0.0001), role physical (p<0.0001), bodily pain (p<0.0001), general health (p<0.0001), vitality (p<0.0001), and social functioning (p<0.002), were significantly lower in the patients than in the healthy subjects. Four weeks after treatment, physical functioning (p=0.003), role physical (p=0.021), bodily pain (p=0.016), general health (p=0.013), vitality (p=0.031) and social functioning (p=0.035) improved significantly from baseline in the patients. However, at 4 weeks, patients in the active control group were withdrawn from the study because their pain did not improve, and continuation without further medical care was considered unethical.

CONCLUSION:

A low dose of botulinum toxin type A relieved pain and improved quality of life in patients with refractory piriformis syndrome.

• Authors: Se Jin Yoon, Jin Ho, Ho Yeong Kang, Sang Ho Lee, Kyung Im Kim, Wan Gyoon Shin, Jung Mi Oh
• Journal: Pharmacotherapy (Pharmacotherapy) Vol. 27 Issue 5 Pg. 657-65 (May 2007) ISSN: 0277-0008 [Print] United States
• PMID: 17461700 (Publication Type: Clinical Trial, Comparative Study, Journal Article)

Chemical References

• Anesthetics, Local
• Glucocorticoids
• Neuromuscular Agents
• Dexamethasone
• Lidocaine
• Botulinum Toxins, Type A

Topics

• Adult
• Anesthetics, Local (therapeutic use)
• Asian People
• Botulinum Toxins, Type A (adverse effects, therapeutic use)
• Dexamethasone (therapeutic use)
• Female
• Glucocorticoids (therapeutic use)
• Humans
• Korea
• Lidocaine (therapeutic use)
• Male
• Middle Aged
• Muscle Contraction (drug effects)
• Muscle Stretching Exercises
• Muscle, Skeletal (drug effects)
• Neuromuscular Agents (adverse effects, therapeutic use)
• Pain (drug therapy)
• Pain Measurement
• Prospective Studies
• Quality of Life
• Rehabilitation Centers
• Sciatic Nerve (physiopathology)
• Syndrome
• Tomography, X-Ray Computed