The present randomized, comparative trial aims to clarify the efficacy of traditional acupuncture vs. aspecific needle skin stimulation in treating persistent pain in subjects with spinal cord injury, by overcoming the biases reported in previous studies. Because of the intrinsic effects of sham acupuncture and, generally, of skin stimulation, a statistically significant change in the Numerical Rating Scale (NRS) measurements is expected even in the comparison group. To minimize this bias, which cannot be avoided, and to maintain the blindness of the patient as much as possible, the comparison group is treated by the insertion of needles in skin areas outside the metamer(s) affected by pain.