rTMS for the Treatment of Neuropathic Pain in Diabetic Patients

High Frequency rTMS for the Treatment of Neuropathic Pain in Diabetic Patients

Tis study aims to assess whether multiple sessions of sham-controlled HF-rTMS applied to the motor cortex significantly reduces treatment-resistant neuropathic pain in diabetic patients.

This study will also investigate the effect of those rTMS sessions on functional connectivity of the M1 with brain areas involved in pain processing, underlying brain metabolism and brain plasticity using rs-fMRI, MRS and Paired-pulse stimulation respectively in those patients.

Subjects will be randomized into two groups to receive real or sham rTMS protocol. A washout period of at least 8 weeks will be respected between protocols to minimize carry-over effects. Sham stimulation will be delivered using a sham coil, providing the same auditory and sensory stimuli.

One daily rTMS session for 5 days of HF-rTMS, will be delivered through an H-coil applied to the primary motor area of the leg. Each session will last 20 minutes during which 30 consecutive trains of 50 stimuli will be delivered at 20 Hz at 100% of resting motor threshold (RMT), with an intertrain interval of 30s

Inclusion Criteria:

• Written informed consent to participate in this study is obtained
• The subject is an out-patient aged 18 years or above with diabetes mellitus type 1 or 2
• The patient has laboratory-confirmed diabetes
• Patients are diagnosed with peripheral neuropathy based on clinical and electrophysiological findings
• A score of > /= 4 on the the 'Douleur Neuropathique en 4 Questions' (DN4) questionnaire (30), conforming the diagnosis of neuropathic pain.
• The patient has a painful diabetic neuropathy for at least 6 months
• The patient has a Numeric pain rating scale (NPRS) score >/= 4.
• The patient is resistant to standard therapies for neuropathic pain

Exclusion Criteria:

• The patient has an implanted cardiac device, such as a pacemaker or a defibrillator
• The patient has an implanted neurostimulator
• The patient has cochlear implants/ear implants, magnetic dental im-plants
• The patient has a drug infusion pump
• The patient has cerebral artery aneurysm clips
• The patient has a history of epilepsy
• The patient has a history of migraine or severe headaches
• The patient has significant psychiatric disorders
• For female patients: the subject is pregnant or lactating
• Other formal contra-indication for rTMS or MRI