Journal: Pain (Oct 2023)
Authors: Didier Bouhassira, Frédérique Jazat-Poindessous, Nadine Farnes, Claire Franchisseur, Audun Stubhaug, Julie Bismuth, Jean-Pascal Lefaucheur, Per Hansson, Nadine Attal
We conducted a direct comparison of the analgesic effects resulting from “superficial” and “deep” repetitive transcranial magnetic stimulation (rTMS) applied to the primary motor cortex in patients with central neuropathic pain. A total of fifty-nine consecutive patients were randomly assigned to receive either active or sham “superficial” stimulation (utilizing a figure-of-8 [F8]-coil) or “deep” stimulation (using a Hesed [H]-coil) in accordance with a double-blind crossover design. Each treatment period involved 5 daily stimulation sessions, followed by 2 post-treatment visits at 1 and 3 weeks after the final stimulation session. The primary outcome measure was the comparison of the mean change in average pain intensity throughout the treatment (group × time interaction). Secondary outcomes encompassed neuropathic symptoms (NPSI), pain interference, patient global impression of change (PGIC), anxiety, depression, and catastrophizing. Of the total participants, 51 patients took part in at least one session of both treatments.
Results indicated a significant interaction between “treatment” and “time” (F = 2.7; P = 0.0024), signifying that both figure-8 (F8-coil) and H-coil active stimulations induced significantly greater analgesic effects compared to sham stimulation. Although the analgesic effects of both coil types were of similar magnitude, they showed only moderate correlation (r = 0.39, P = 0.02). The effects of F8-coil stimulation manifested earlier, while H-coil stimulation produced delayed effects that tended to persist longer (up to 3 weeks), as observed in various secondary outcomes (PGIC and total NPSI score). In conclusion, both “deep” and “superficial” rTMS elicited analgesic effects of similar magnitude in patients with central pain, suggesting the involvement of distinct mechanisms of action.
Full Article:
https://pubmed.ncbi.nlm.nih.gov/37851075/