Ablative procedures for chronic pain Pantaleo Romanelli, MD a,b,c, * , Vincenzo Esposito, MD a,b , John Adler, MD c a Epilepsy Surgery Unit, Neuromed IRCCS, Via Atinense 18, 86077 Pozzilli (IS), Italy b Department of Neurosurgery, University ‘‘La Sapienza,’’ Rome, Italy c Department of Neurosurgery, Stanford University, 300 Pasteur Drive, Room 200, Stanford, CA 94305, USA Ablative surgery has played an important role in the management of chronic pain during the twentieth century. Recently, there has been a steady trend toward the application of non- destructive techniques, such as spinal cord, deep brain, and motor cortex stimulation, which have progressively replaced such procedures as cordot- omies, dorsal root entry zone (DREZ) lesions, sympathectomies, and neurectomies. Although neuroaugmentation is now the preferred strategy for the management of neuropathic pain of functional origin, the use of ablative techniques remains quite established for the management of medically refractory pain related to malignancies, especially in terminally ill patients. Ablative techniques can produce fast and satisfactory pain relief, but their effect is usually limited in time, restricting their use mostly to terminal patients suffering from cancer pain. These procedures obviously need to be performed by neurosurgeons specializing in pain management because of the complexity of medical, surgical, and ethical considerations involving the treatment of terminal patients plagued by excruciating pain (not to mention the technical demands of the procedure). Recent improvements in imaging technologies (especially functional imaging) and radiosurgical technologies could make radiosurgery an impor- tant player in the treatment of refractory pain in the near future. Current applications of radio- surgery for the treatment of pain are briefly reviewed. Ablative procedures involving spinal targets The aim of spinal cord ablative procedures is to interrupt the nociceptive pathways running through specific sectors of the spinal cord itself, namely, the DREZ, the spinothalamic pathway, and the midline posterior column visceral path- way. DREZ lesions can be used to destroy the superficial laminae of the dorsal horn, where the central processing of pain begins. Anterolateral cordotomy targets the spinothalamic pathway that carries somatic pain. The destruction of the spinothalamic pathway within the anterolateral quadrant of the cord is usually followed by abolition of pain and temperature sensation below the level of the lesion. The main difference between cordotomies and DREZ lesions is that the latter can produce analgesia over a restricted area in a segmental fashion, whereas the former produces analgesia covering the whole hemibody below the level of the section. Visceral pain has its own pathway located in the deep and medial region of the dorsal columns. Midline myelotomy is a recently described technique to relieve visceral pain by lesioning this pathway. Dorsal root entry zone lesion Ablative surgery of the DREZ in the spinal cord is considered a good surgical option in patients with segmental paroxysmal and allodynic pain related to peripheral nerve, root, and spinal cord lesions. This operation aims to destroy the superficial layers of the dorsal horn, thus inter- rupting the afferent pain pathway. The success of a DREZ operation depends essentially on the ability to select the proper level at which to place * Corresponding author. E-mail address: leoromanelli@neuromed.it (P. Romanelli). 1042-3680/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.nec.2004.02.009 Neurosurg Clin N Am 15 (2004) 335–342