150 Mesencephalotomy for Cancer

Mesencephalotomy as a treatment for pain has evolved in a manner that reflects the changing approach to pain management through the years. As such, a review of mesencephalotomy provides insight into the evolution of concepts of surgical pain management. More than a century ago, the primary pain pathway was demonstrated, first clinically, then in the laboratory and finally in the operating room. The rationale of the spinothalamic tract was introduced after the post-mortem examination of a patient who was known to have suffered a gun shot wound in 1878. The patient had lost unilateral pain sensation but had retained touch sensation. A second patient with a similar loss of sensation from a spinal tuberculoma led Spiller [1] to recognize in 1905 that the pain pathway within the spinal cord was located in the anterolateral columns. His observations reassured Martin [2] sufficiently for them to report in 1912 their success in treating pain by surgical section of the anterolateral spinal cord. Since that time, anterolateral cordotomy has been used more often than any other procedure for pain management. However, if the pain occurs in the upper extremities, upper body, or even in the face, it becomes necessary to interrupt the primary pain pathway at a level above