Surgery in the Dorsal Root Entry Zone for Pain

The dorsal root entry zone (and dorsal horn)—which is the first important level of modulation for pain sensation—can be a neurosurgical target to treat resistant pain. Lesioning techniques include microsurgical coagulation, radiofrequency thermocoagulation, laser beam or ultrasound lesion maker. Indications are (1) malignant pain in patients with long life expectancy and cancer that is limited in extent (such as in Pancoast-Tobias syndrome); (2) persistent neuropathic pain that is due to (a) brachial plexus injuries, especially those with avulsion, (b) spinal cord lesions (predominantly in the conus medullaris), especially the pain corresponding to segmental lesions (pain below the lesion is not favorably influenced), (c) segmental pain caused by lesions in the cauda equina, (d) peripheral nerve injuries, amputation, or herpes zoster, when the predominant component of pain is of the paroxysmal type and/or corresponds to provoked allodynia or hyperalgesia; and (3) disabling hyperspastic states with pain.