Journal: European Journal of Pain 17(9):1347-1356 (2013)
Authors: E Onesti, M Gabriele, C Cambieri, M Ceccanti, R Raccah, G Di Stefano, A Biasiotta, A Truini, A Zangen, M Inghilleri
Painful neuropathy is associated with plasticity changes inthe nervous system. Standard repetitive transcranial magnetic stimulation(rTMS) is a non-invasive technique used to study changes in corticalexcitability and to inhibit pain perception. Deep rTMS is a newerdevelopment that allows direct activation of deeper neuronal populations,by a unique coil design termed the H-coil.
This study was designed to assesswhether deep rTMS applied over the motor cortical lower-limb representation relieves pain in patients with diabetic neuropathy.
Patients were randomly assigned to receive daily real or shamH-coil rTMS for 5 consecutive days. After a 5-week washout period, theycrossed over to the alternative treatment for additional 5 days (accordingto a crossover study design). Outcome measures were changes in the visualanalogue scale (VAS) for pain and in area and threshold of RIII nociceptiveflexion reflex (RIII reflex).
Of the 25 patients randomized, 23 completed the study. After real rTMS, the VAS scores decreased significantly (p=0.01), and so did RIII reflex area (p<0.01), while no significant effects in these variables were induced by thesham rTMS treatment. The rTMS-induced changes in the outcome measures disappeared about 3 weeks after stimulation. Allpatients tolerated stimulation well.
Deep H-coil rTMS provides pain relief in patients with diabetic neuropathy. This innovative technique can induce a therapeutic effect on brain areas that otherwise remain difficult to target. rTMS may produce its analgesic effects, inducing motor cortex plasticity and activating descending inhibitory pain control systems.