PERCUTANEOUS CERVICAL CORDOTOMY - A REVIEW OF 181 OPERATIONS ON 146 PATIENTS WITH A STUDY ON THE LOCATION OF PAIN FIBERS IN THE C-2 SPINAL-CORD SEGMENT OF 29 CASES

The authors present a review of 146 patients who underwent 181 percuta neous cervical cordotomies for intractable pain. In addition, an anato mical-clinical correlation was carried out for 29 of these patients. I t was found that the fibers subserving pain sensation in the C-2 segme nt lie in the anterolateral funiculus between the level of the denticu late ligament and a line drawn perpendicularly from the medial angle o f the ventral gray-matter horn to the surface of the cord. The best an algesic results have been obtained by creating lesions that extend 5.0 mm deep to the surface of the cord and destroy about 20% of the hemic ord. There is a somatotopic organization with sacral fibers running ve ntromedially and cervical fibers running dorsolaterally. The authors b elieve that the ascending fibers subserving the distinct sensations of pain induced by tissue damage and pinprick, although mixed (overlappi ng) in the anterolateral funiculus of the spinal cord, are physiologic ally distinct from one another. Whereas some cordotomies, both in the current series and as reported in the literature, may affect these fun ctions differentially, optimum pain relief seems to be obtained only w hen pinprick sensation is also abolished in the affected segments. Evo ked pain sensation is not abolished by cordotomy, but its threshold is greatly raised. When pathological pain is completely abolished, so is pinprick sensation. However, in a number of cases where pathological pain was only partially alleviated, pinprick sensation remained intact . The significance of these and other cases reported in the literature is discussed. The importance of clinically distinguishing between pai n caused by tissue damage and pinprick sensation is emphasized, as wel l as that between return of pre-existing or new tissue-damage pain and painful dysesthesia.