Botulinum Toxin A
In another study exploring nonsystemic treatment modalities, Jabbari B. found that patients with chronic low back pain may respond to injections of botulinum toxin A. In a prospective study involving 75 patients, patients received paraspinal intramuscular injections at baseline and then at recurrence of pain, typically at 4, 8, and 12 months after the initial therapy. Although a modest number of patients reported significant improvement, 56% at 3 weeks and 54% at 2 months, the investigators did note that among initial responders, 90% responded to subsequent treatments. Among the patients overall, there were 3 adverse events — 2 transient flulike reactions and 1 episode of acute root pain after the injection.