OR WAIT null SECS
TMS Reduces Pain, Yields Functional Improvements in Women With Fibromyalgia
Analgesic effects lasted up to week 8 while function improvements lasted until week 16 in a new randomized, controlled trial.
Add-on M1-repetitive transcranial magnetic stimulation (rTMS) reduced pain intensity for up to 8 weeks in women with fibromyalgia, with functional improvements remaining at 16 weeks, according to new findings from a randomized, double-blind clinical trial.1
“In smaller trials, rTMS has been tested in people with fibromyalgia, with stimulation targeting mainly M1 or the dorsolateral prefrontal cortex. Results of these trials are conflicting owing to several factors, such as the nonsystematic inclusion of fibromyalgia patients with comorbid major depression, heterogeneous outcome measures, relatively small sample sizes, and short follow-up. More importantly, key stimulation parameters were frequently either not reported or were suboptimal2,” lead investigator Valquíria A. Silva, RN, MS, PhD, Pain Center, Department of Neurology, and Clinical Research Manager, Service of Interdisciplinary Neuromodulation (SIN), Department and Institute of Psychiatry, University of São Paulo, São Paulo, Brazil, and colleagues wrote.1
Silva and colleagues enrolled 101 adult women with fibromyalgia refractory to best available treatment in centers in Brazil, France, and Japan. Participants were randomized to 10 Hz motor cortex (M1) rTMS, 3000 pulses day−1 (n – 52), or sham stimulation (n = 49) for 10 induction sessions over 2 weeks, followed by weekly maintenance for 6 weeks, and fortnightly extended maintenance for 8 weeks. The trial’s primary outcome was at least a 50% pain reduction at week 8 compared with baseline, with secondary outcomes including pain interference, mood, global impression of change, and Fibromyalgia Impact Questionnaire (FIQ) scores at weeks 8 and 16.1
Participants had a mean age of 48 years (range, 25-83). The investigators found a 99.4% probability of ≥50% pain reduction at week 8 using Bayesian analysis, a 3.04 odds ratio (OR) compared with sham (95% CI, 1.26-8.06), with a number needed to treat of 4.54. They also found that relative pain reduction was higher in the active (40.4%) than in the sham group (18.4%; P = .028) with Frequentist analysis. At week 16, this probability reduced to 34.2% (OR, 0.815; 95% CI, 0.313–2.1), but FIQ score reduction still had a likelihood of 79.1%.1
Adverse events (AEs) were similar between arms, and commonly reported AEs included headache (rTMS, 15.4%; sham, 16,3%; p = 0.897), neck pain (rTMS, 13.5%; sham, 10.2%; P = .613), and somnolence (rTMS, 13.5%; sham, 10.2%; P = .613). There were no deaths or seizures and 80.8% of the rTMS group and 75.5% of the sham group reported no AEs at week 8.1
“In conclusion, this is the first multicenter study which showed that M1-rTMS leads to a high probability of relevant pain relief in women with fibromyalgia up to 8 weeks, with a relatively high effect size and an apparently good safety profile. Although these data help include noninvasive brain stimulation approaches to pain relief among the treatment options for fibromyalgia, efforts are needed to better characterize the response profile and personalize this therapy to improve the success rate further,” Silva and colleagues concluded.1
