Treatment of refractory, chronic low back pain with botulinum neurotoxin A: an open-label, pilot study.
OBJECTIVE
To study the short- and long-term effects of botulinum neurotoxin A (BoNT-A, Botox, Allergan Inc.) on refractory chronic low back pain.


METHODS
The effect of botulinum neurotoxin A on chronic low back pain was prospectively studied in 75 patients with repeated treatments over a period of 14 months. Pain intensity (visual analog scale [VAS]), pain frequency (pain days), and perceived functional status (Oswestry scale) were assessed at baseline, 3 weeks, and at 2, 4, 6, 8, 10, 12, and 14 months. BoNT-A was injected into para-spinal muscles at 4-5 levels (between L1 and S1) unilaterally or bilaterally. The dose per site varied from 40 to 50 units. The total dose per session ranged from 200 to 500 units. Reinjections were performed at 4 months only when pain returned.


RESULTS
At 3 weeks, 40 patients (53%) and at 2 months, 39 patients (52%) reported significant pain relief. The change in VAS, Oswestry score, and pain days was significant compared with baseline at 2 months after each injection period (P < 0.005) and remained so over subsequent treatments. Among initial responders, 91% continued responsiveness over the length of the study. Three patients (4%), after the first treatment, had a mild flulike reaction that lasted 2-5 days.


CONCLUSIONS
Botulinum neurotoxin A may be beneficial in patients with chronic low back pain. A favorable initial response predicts subsequent responsiveness. The treatment is well tolerated, and side effects are mild and transient.
Jabbari
Bahman
B
Department of Neurology, Yale University, New Haven, Connecticut 06520, USA. bahman.jabbari@yale.edu
Ney
John
J
Sichani
Afsoun
A
Monacci
William
W
Foster
Leslie
L
Difazio
Marc
M
D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000187:drug effects; D010865:Pilot Projects; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D055502:Secondary Prevention; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
D019274:Botulinum Toxins, Type A