H-coil repetitive transcranial magnetic stimulation for pain relief in patients with diabetic neuropathy

Eur J Pain. 2013 Oct;17(9):1347-56. doi: 10.1002/j.1532-2149.2013.00320.x. Epub 2013 Apr 29.


Background: Painful neuropathy is associated with plasticity changes in the nervous system. Standard repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique used to study changes in cortical excitability and to inhibit pain perception. Deep rTMS is a newer development that allows direct activation of deeper neuronal populations, by a unique coil design termed the H-coil. This study was designed to assess whether deep rTMS applied over the motor cortical lower-limb representation relieves pain in patients with diabetic neuropathy.

Methods: Patients were randomly assigned to receive daily real or sham H-coil rTMS for 5 consecutive days. After a 5-week washout period, they crossed over to the alternative treatment for additional 5 days (according to a crossover study design). Outcome measures were changes in the visual analogue scale (VAS) for pain and in area and threshold of RIII nociceptive flexion reflex (RIII reflex).

Results: 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 the sham rTMS treatment. The rTMS-induced changes in the outcome measures disappeared about 3 weeks after stimulation. All patients tolerated stimulation well.

Conclusions: 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.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cross-Over Studies
  • Diabetic Neuropathies / physiopathology
  • Diabetic Neuropathies / therapy*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Motor Cortex / physiopathology*
  • Pain Management
  • Pain Measurement
  • Transcranial Magnetic Stimulation / methods*
  • Treatment Outcome