The purpose of this study is to evaluate the analgesic effect of transcutaneous spinal direct current stimulation (tsDCS) applied on spinal cord in patients with spinal cord injury who have chronic neuropathic pain.

Twenty patients with spinal cord injury and bilateral neuropathic pain received single sessions of both sham and anodal tsDCS (2 mA) over tenth thoracic vertebra for 20 min (reference electrodes on the head vertex). Treatment order was randomly assigned. A evaluator rated the pain using the visual analogue scale for pain, Patient Global Assessment and Present Pain Intensity.

Inclusion Criteria:

1. cervical or upper thoracic complete motor spinal cord injury, at least 6 months after SCI, 20<=age<90
2. neuropathic pain (LANSS score >= 12), stable chronic pain for at least the three preceding months but not over 5 years
3. score higher than or equal to 4 cm (0 cm = 'no pain' and 10 cm = 'worst possible pain') on the visual ana- logue scale (VAS) for pain perception at the baseline/start of the treatment
4. refractoriness to drugs for pain relief - such as tricyclic antidepressants, antiepileptic drugs, and/or narcot- ics (pain resistant to at least two of these drugs supplied in ade- quate dosages for 6 months)
5. informed consent

Exclusion Criteria:

1. patients with any clinically significant or unstable medical or progressive neurologic disorder
2. contraindication for electrial stimulation such as pacemaker implant
3. Women of childbearing age or pregnancy
4. significant cognitive deficit
5. Syringomyelia
6. neuropsychiatric comorbidity
7. depressive disorder (as indicated by a score of 10 greater on the Beck Depression Inventory)
8. history of substance abuse
9. skin defect under the electrodes
10. progressive neurological disease or other secondary conditions that could impact neuropathic pain

tsDCS