Dorsal column stimulation
This is a technique for intractable pain. Electrodes are placed above the highest level of the pain and connected to a subcutaneous inductance coil, usually on the abdominal wall, by insulated wires. The patient then applies an external power source over the coil for pain relief.
Dorsal root entry zone procedure (DREZ)
This procedure is indicated for post-herpetic neuralgia, central pain and severe cancer pain. A small electrode is inserted into the spinal cord at each level of the pain, and radiofrequency lesions are induced to destroy the abnormally active dorsal horn neurones. The procedure is believed to interrupt the pain pathways via the lateral spinothalamic and spinoreticulothalamic tracts.