title: Effects of regional intravenous guanethidine in patients with neuralgia in the hand; a follow-up study over a decade.
abstract: A study on the effect of regional intravenous (i.v.) guanethidine blockade (RGB) was done over a 10 years period in patients with post-traumatic neuralgia. Seven patients, investigated with quantitative sensory testing (QST) before and after RGB between 1979 and 1982, were reinvestigated in the period 1990-1992. In addition to the RGB, 6 patients were subjected to a placebo procedure with tourniquet inflation and i.v. injection of saline at follow-up. All patients had ongoing pain and stimulus-induced pain (hyperalgesia) in one hand. The QST was done by an independent observer who was blind with regard to the different treatments. Three patients with long-lasting relief of ongoing pain and significant reduction of stimulus-induced pain after RGB, were classified as having sympathetically maintained pain (SMP) both at 1st examination and at follow-up 10 years later. In 2 patients, classified as having sympathetically independent pain (SIP), neither the ongoing pain nor the hyperalgesia improved at any occasion. Two patients, classified as SMP in 1979-1982, changed to SIP at follow-up. Placebo had no significant effect on the hyperalgesia to heat, cold or vibration in the 6 SMP/SIP patients tested. In conclusion, some patients with neuralgia, diagnosed 17-26 years ago, still had long-lasting pain relief from an i.v. RGB, whereas others consistently had no such effect. None obtained long-lasting pain relief from placebo. This supports the notion that different pathophysiological mechanisms are involved in post-traumatic neuralgia.
authors.affiliation: Department of Clinical Neurophysiology, University of Hospital, Uppsala S-751 85, Sweden Department of Anesthesiology, University of Hospital, Uppsala S-751 85, Sweden.
authors.forename: Lis Karin
authors.initials: LK
authors.lastname: Wahren
authors.forename: Torsten
authors.initials: T
authors.lastname: Gordh
authors.forename: Erik
authors.initials: E
authors.lastname: Torebjörk
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000098:blood supply; D001340:Autonomic Nerve Block; D005260:Female; D005500:Follow-Up Studies; D006145:Guanethidine / Q000008:administration & dosage* / Q000627:therapeutic use; D006358:Hot Temperature; D006801:Humans; D007275:Injections, Intravenous; D007511:Ischemia / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement; D012684:Sensory Thresholds; D012965:Sodium Chloride / Q000008:administration & dosage; D014111:Tourniquets; D014732:Vibration
chemical_list: D012965:Sodium Chloride; D006145:Guanethidine