History of neuroaugmentative procedures.

Neuroaugmentation, the use of chronic stimulation of the brain and spinal cord for pain management, developed during the past 30 years. It evolved, however, from concepts of pain treatment that were based on observations and clinical experience dating back an additional two decades or more. The appreciation of the role of the extralemniscal system and descending influences from the brain in modulation of pain perception led to the Melzack-Wall gate theory. The concept proposed in that theory, that pain perception could be lessened by increasing activity in neural structures not associated with pain, led to chronic stimulation of deep brain and spinal cord as a modality for the management of chronic pain. Both brain and spinal structures emerged as targets for neuroaugmentation.