Spinal cord stimulation.

Spinal cord stimulation is the most common mode of neuromodulation used in managing chronic low back pain. It is minimally invasive and reversible as opposed to nerve ablation. The basic scientific background of the initial spinal cord stimulation trials was based on the gate control theory of Melzack and Wall. It has been demonstrated in multiple studies that dorsal horn neuronal activity caused by peripheral noxious stimuli could be inhibited by concomitant stimulation of the dorsal columns. Various other mechanisms, which may play a significant role in the mechanism of action of spinal cord stimulation, include the suppressive effect of spinal cord stimulation on tactile allodynia, increased dorsal horn inhibitory action of gamma-aminobutyric acid (GABA), prevention or abolition of peripheral ischemia, and effects on human brain activity. Spinal cord stimulation is indicated in low back pain with radiculopathy, failed back surgery syndrome, complex regional pain syndrome, peripheral vascular disease, and ischemic heart disease. There is substantial scientific evidence on the efficacy of spinal cord stimulation for treatment of low back and lower extremity pain of neuropathic nature. Clinical studies revealed a success rate of from 50% to 70% with spinal cord stimulation, with decreased pain intensity scores, functional improvement and decreased medication usage. This review discusses multiple aspects of spinal cord stimulation, including pathophysiology and mechanism of action, rationale, indications, technique, clinical effectiveness, and controversial aspects.