Moderate-level evidence exists to support repetitive transcranial magnetic stimulation (rTMS) as a potentially effective therapy for reducing headache frequency intensity, duration, depression, abortive medication use, and functional impairment in people with headache disorders. This is according to findings from a systematic review published in Headache.
Independent researchers reviewed the published literature and selected cohort, case-control, and randomized controlled trials that included adult participants up to age 65 with primary or secondary headaches. Selected trials included TMS and transcranial direct current stimulation (tDCS) as well as sham or alternative standard-of-care interventions as comparators. Due to the heterogeneity among study methods and participants, the researchers performed a structured synthesis of the data. Primary outcomes included headache frequency and response rate, whereas secondary outcomes included headache duration, pain intensity, depression, anxiety, functional impairment, use of abortive medications, and quality of life.
Studies included in the review examined the efficacy of rTMS (n = 16), TMS (n = 6), and tDCS (n = 12), and most of the studies investigated the impact of these treatments on migraine.
A study which exposed 11 participants to 12 rTMS sessions found significant Treatment × Time interactions for attack frequency (P <.0002), number of abortive pills (P <.0001), and headache index (P <.0001). Noticeable changes were observed at 2-month follow-up in the number of attacks per month (-13 attacks/month [TMS] vs -1.8 [placebo]; mean Cohen’s d = 2.15), number of abortive pills (20 pills/month [TMS] vs 1.4 [placebo]; Cohen’s d = 1.84), headache index (36 [TMS] vs 4.8 [placebo]; Cohen’s d = 2.09).
Another study found a significant >50% reduction in both headache frequency and visual analog scale (VAS) score among participants who received rTMS vs sham control at 1-month follow-up [78.7% vs 33.3%, respectively; odds ratio [OR] 7.4; 95% CI, 2.95-18.59; P =.0001) and VAS score (76.6% vs 27.1%, respectively; OR 8.81; 95% CI, 3.48-22.29; P =.0001).
The lack of a full quantitative synthesis of the data as well as the lack of concealed treatment allocation protocols in some studies represent limitations of the review.
“In addition to their mild side effect profile,” the researchers explained, “these [TMS] technologies could be beneficial in patients who are treatment resistant to conventional therapies or those with contraindications to oral pharmacologic management.”