Noninvasive Cortical Neurostimulation For Diabetic Neuropathic Pain

Treatment of Pain and Sensory Dysfunction in Diabetic Neuropathy by Brain Neuromodulation

To investigate whether transcranial direct current stimulation can alleviate pain and sensory related disturbances in individuals with type 1 diabetes and peripheral neuropathy through neuromodulation of the CNS as compared to sham treatment.

This study is a randomized, cross-over, controlled investigation. The overall objective of this study is to assess the pain-relieving effect of four weeks' transcranial direct current stimulation (tDCS) in individuals with type 1 diabetes and painful polyneuropathy not responding adequately to traditional pharmacological pain treatment, in comparison to the effect of four weeks' sham treatment. Both treatments will be performed using a commercially available and validated device called Sooma tDCS. Sooma tDCS device is a non-invasive neurostimulator that has been CE-marked for the treatment of depression, chronic pain including neuropathic pain and fibromyalgia. The study will begin with a 2-week baseline registration period, in which the patients will receive no treatment. Next, the baseline period will be followed by a 4-week treatment period where the subjects will be randomized to either active treatment or sham treatment. Afterwards, a wash-out period of 6 weeks will occur. Finally, in the second treatment period the patients will switch in treatment assignment, meaning that patient who received active treatment will now receive sham treatment and vice versa. During both treatments, the patients will be asked to self-administer one stimulation dose daily, five times a week. During the whole study, subjects will be asked to complete a pain diary and several questionnaires. Moreover, at the beginning and end of each treatment period (four times), all subjects will undergo testing which will include brain magnetic resonance imaging (MRI) and quantitative sensory testing (QST). The primary efficacy parameters to be evaluated are short and longer lasting alleviation of clinical chronic pain and quality of life.

Inclusion Criteria:

• Minimum age of 18 years.
• Type-1 diabetes
• Clinically established peripheral neuropathy
• DN4 of ≥4 points indicating that the patient is suffering from neuropathic pain.
• NRS pain scores >3
• Acceptable screening blood samples according to medical judgement
• Signed informed consent

Exclusion Criteria:

• Contraindications to MRI
• Not being able to understand Danish (written and/or verbally)
• Not being able to comply with the study procedures including home-treatment e.g., due to senile dementia, etc.
• Previous brain surgery
• Present alcohol or drug abuse
• Major mental and psychiatric disorders
• Pregnancy
• Active cancer-disease
• Known neural damage or disease in the neural system (e.g., MS or Guillain-Barre) other than diabetic neuropathy
• Previous chemotherapy or intake of experimental medicine
• Active herpes simplex virus or varicella zoster virus infection or known HIV
• Other reasons for limb pain (e.g., critical limb ischemia and lower back pain with radiating pain etc.)