EFFECTS OF DORSAL-ROOT ENTRY ZONE LESIONS ON CSF AND PLASMA NEUROPEPTIDES AND CATECHOLAMINES

Effects of dorsal root entry zone lesions (DREZLs) on cerebrospinal fluid (CSF) and plasma concentrations of neuropeptides, catecholamines, and cyclic nucleotides were studied in 9 patients with intractable chronic pain. Contents of beta-endorphin-like-material in CSF decreased in all patients 12-17 days following DREZLs during which complete to good pain relief was achieved. Contents of beta-endorphin-like-material in CSF increased again about one month after DREZLs in two and remained unchanged in one of three patients tested, who complained of partial reappearance of pain. Contents of beta-endorphin-like-materials in plasma showed no significant changes after DREZLs. Substance P, noradrenaline, adrenaline, and cyclic nucleotide levels in both CSF and plasma were variable among the subjects and did not change significantly following the operations. Thus, the results suggest that production of beta-endorphin-like-material in the central nervous system is decreased by DREZL, though the increase in its tum-over might not be neglected. The mechanisms of the decrease in contents of beta-endorphin-like-material in CSF after DREZLs were discussed in terms of our current knowledge of pain and pain inhibitory systems.