Deafferentation Pain Exacerbated by Subarachnoid Lidocaine and Relieved by Subarachnoid Morphine: Case Report. Issue 3 (May 1994)

• Record Type: Journal Article
• Authors: Iacono, Robert P.; Boswell, Mark V.; Neumann, Monica
• Is Part Of: Regional anesthesia. Volume 19:Issue 3(1994)
• Page Start: 212
• Page End: 215
• Publication Date: 1994-05
• Subjects: neuropathic pain -- deafferentation -- spinal anesthesia -- spinal cord stimulation -- evoked potentials -- subarachnoid morphine -- hydromorphone; Conduction anesthesia -- Periodicals; Pain medicine -- Periodicals; 617.964
• DOI: 10.1136/rapm-00115550-199419030-00011
• Languages: English
• ISSNs: 0146-521X

Abstract

Abstract : Background and Objectives: Neuropathic pain syndromes are often resistant to traditional pharmacologic treatment. The authors describe a patient with chronic deafferentation pain of the legs associated with peripheral neuropathy that was refractory to multidisciplinary pain clinic management. Methods: Numerous medications had been tried, including nortriptyline, mexiletine, and oral and parenteral opioids. Spinal cord stimulation was also ineffective, despite a satisfactory pattern of stimulation-induced paresthesias. For diagnostic purposes, differential spinal anesthesia with lidocaine and morphine was performed, with evoked potential monitoring used to evaluate the intensity of spinal anesthetic block. Results: Paradoxically, lidocaine spinal anesthesia exacerbated pain, whereas subarachnoid morphine provided rapid pain relief. Longterm pain control has been maintained with an implanted spinal infusion pump. Conclusions: Evoked potential data acquired during lidocaine spinal anesthesia and the rapid pain relief provided by subarachnoid morphine suggest that deafferentation pain may involve segmental, opioid-sensitive dorsal horn pain generators. The long-term pain relief afforded the patient demonstrates that subarachnoid opioids may be efficacious for some forms of neuropathic pain.