Articles: neuropathic-pain.
-
Objectives. To test the efficacy and safety of intraspinal opioids for patients with nonmalignant pain. Design. ⋯ Conclusions. Long-term intrathecal opioids are efficacious, practical, and safe for the treatment of nonmalignant pain syndromes. FBSS patients respond similarly to intraspinal analgesia as the patients with neuropathic pain, while the group with mixed pain from other non-FBSS causes respond similarly to the nociceptive pain patients.
-
Injured sensory axons trapped in a neuroma or freely regenerating in the distal nerve stump, frequently display ectopic mechanosensitivity, spontaneous impulse discharge or both. This abnormal neural activity is thought to contribute to spontaneous and movement-evoked neuropathic paraesthesias, dysaesthesias and pain, as well as to allodynia and hyperalgesia. ⋯ This suggests that mechanosensitivity and spontaneous firing are aspects of a single underlying pathophysiological process. Copyright 1998 European Federation of Chapters of the International Association for the Study of Pain.
-
To provide a brief review of the current state of topical treatment with capsaicin or acetylsalicylic acid (ASA) for therapy of chronic pain syndromes. ⋯ Capsaicin is a white crystalline parent compound of a group of vanillyl fatty acid amines. Because of its highly specific action in neurons it has become an important tool in neuroscience. Because of its effects, it is obvious to try for the therapy of circumscribed neuropathic pain. Capsaicin acts by depleting stores of substance P and other neurotransmitters, resulting in a blockade of a specific group of sensory afferents. The corresponding clinical findings are initial burning and a desensitization of specific C fiber nociceptors after repeated application. The pain relieving potency was observed in various clinical investigations and even in a few controlled, double-blind studies about neuropathic pain syndromes and (osteo)arthritis. In contrast to these findings, a recent study found no significant benefit of capsaicin, probably because this study was the first to use an active placebo. Therefore, and because clinical efficacy and advantages over other therapies have not been demonstrated up to now, capsaicin cannot be classified as standard therapy. It may be a therapeutic option as an alternative or as an adjuvant treatment. Pain reduction was also observed after topical application of ASA/ether mixture in the one and only controlled double-blind study on this issue. Therefore, topical ASA therapy for (post)herpetic neuralgia is mainly based on a few enthusiastic case reports rather than on well founded investigations. Furthermore, the discrimination of local from systemic effects, the toxicological profile of longterm topical treatment, and the mechanism of action has not been evaluated. In conclusion, topical ASA cannot be recommended for routine clinical use at present.
-
The idea of using Ketamine to treat chronic pain is mainly based on the central antinoceptive effect of the substance acting as a noncompetitive antagonist at the NMDA-receptor. In the present meta analysis over a period from 1/1981 up to 6/1996 twelve publications (1994-1996), which have dealt the use of Ketamine for patients with chronic pain, are evaluated and discussed. The entire positive evaluation of the drug is based on the results of the studies under consideration. ⋯ Here, the therapy had to break off in two cases. In nine cases the side effects could be suppressed by Droperidol. For the future, research with more study power is necessary to establish Ketamine in the therapy of chronic pain.
-
The antinociceptive effect of alpha(2)-adrenoceptor agonists is mediated by activation of descending inhibiting noradrenergic systems, which modulates 'wide-dynamic-range' neurones. Furthermore, they inhibit the liberation of substance P and endorphines and activate serotoninergic neurones. Despite this variety of antinociceptive actions, there is still little experience with alpha(2)-adrenoceptor agonists as therapeutic agents for use in chronic pain syndromes. ⋯ In isolated cases clonidine has been administered epidurally at a dose of 1500 microg/day for almost 5 months without evidence for any histotoxic property of clonidine. Side effects often observed during administration of alpha(2)-adrenoceptor agonists are dry mouth, sedation, hypotension and bradycardia. Therapeutic interventions are usually not required.