Role of lumbosacral retrograde neuromodulation in the treatment of painful disorders.

BACKGROUND Neuromodulation is an effective and reversible treatment option for chronic intractable pain. Spinal cord stimulation (SCS) represents a field of application of neuromodulation and is known to be effective for several conditions including complex regional pain syndrome (CRPS), failed back surgery syndrome (FBSS), and chronic leg and back pain. SCS has some technical limitations that can be bypassed through retrograde neuromodulation. OBJECTIVE To examine the safety and efficacy of retrograde neuromodulation in consecutive patients with neuropathic pain in the perineum or lower limb. STUDY DESIGN Prospective chart review analyzing one year of retrograde stimulation in our department. METHODS We present a series of 10 patients who underwent retrograde neuromodulation at the University General Hospital of Valencia (Spain). We analyzed the variables that can improve the outcome and help physicians choose retrograde neuromodulation. RESULTS Seven of 10 patients had an effective treatment and 3 patients had an ineffective stimulation. In the group with the effective treatment the most represented type of pain was radiculopathy and perineal pain. LIMITATIONS This is a prospective, single-center study with a relatively small number of patients and no control group. CONCLUSION Retrograde neuromodulation seems to be effective in patients that present with a well localized pain with a clear dermatome distribution. We found retrograde neuromodulation to be effective in radiculopathy related to FBSS. We found it to be limited in the treatment of perineal pain probably due to technical limitations and anatomical reasons besides the lack of knowledge of the etiology of this pain model and the exact mechanisms of action of neuromodulation.