Articles: neuralgia.
-
Anesthesia and analgesia · Oct 1995
Randomized Controlled Trial Clinical TrialSystemic adenosine infusion alleviates spontaneous and stimulus evoked pain in patients with peripheral neuropathic pain.
In seven patients with peripheral neuropathic pain, the effect of systemic adenosine infusion on pain symptoms was evaluated in a double-blind, placebo controlled, cross-over study. The study infusions, adenosine (50 micrograms.kg-1.min-1) or placebo, were given intravenously (IV) during 45-60 min at two separate occasions. Before and during infusions, bedside examination of sensibility and quantitative sensory testing (QST), i.e., assessments of perception thresholds for touch, touch-evoked pain, cold, warmth, painful heat, and cold, were performed. ⋯ Pinprick-evoked pain in the neuropathic areas was reduced from 53 +/- 11 to 29 +/- 10 mm (P < 0.05). No other sensory modality was consistently changed during adenosine infusion. In conclusion, the present study demonstrates that adenosine infusion alleviates spontaneous neuropathic pain, tactile allodynia, and pinprick hyperalgesia in patients with peripheral neuropathic disorders, probably by a central mechanism of action.
-
The oxygen-15 water bolus positron emission tomography (PET) method was used to image regional brain activity in 4 patients with chronic post-traumatic neuropathic pain confined to one lower limb and in 1 patient with post-herpetic neuralgia. In comparison to 13 normal subjects, scans of the patients disclosed a statistically significant decrease in thalamic activity contralateral to the symptomatic side. Examination of the right/left ratio for all the subjects showed that the values for the patients fell at the extremes of the normal range, according to the side of the affected body part. These initial observations suggest that functional alterations in thalamic pain processing circuits may be an important component of chronic neuropathic pain.
-
Review Comparative Study
Topical capsaicin. A review of its pharmacological properties and therapeutic potential in post-herpetic neuralgia, diabetic neuropathy and osteoarthritis.
Capsaicin, the active principle of hot chili pepper, is thought to selectively stimulate unmyelinated C fibre afferent neurons and cause the release of substance P. Prolonged application of capsaicin reversibly depletes stores of substance P, and possibly other neurotransmitters, from sensory nerve endings. This reduces or abolishes the transmission of painful stimuli from the peripheral nerve fibres to the higher centres. ⋯ Topical capsaicin is not associated with any severe systemic adverse effects. However, stinging and burning, particularly during the first week of therapy, is reported by many patients. Topical capsaicin merits consideration as adjuvant therapy in conditions such as post-herpetic neuralgia, diabetic neuropathy and osteoarthritis, where the pain can be chronic and difficult to treat.
-
We have tested the effects of cutaneous application of noradrenaline in 35 patients presenting with neuropathic pain. Depending on the outcome of sympatholytic interventions the patients were considered to have sympathetically maintained pain (SMP; n = 25) or sympathetically independent pain (SIP; n = 10). Iontophoretic application or cutaneous injection of noradrenaline into symptomatic skin aggravated pain and mechanical or thermal hyperalgesia in 7/25 SMP patients. ⋯ None of these 4 and none of the 7 initially noradrenaline-unresponsive patients experienced pain to the noradrenaline challenge at follow-up. Thus, cutaneous noradrenaline application can aggravate the pain in some, but not all SMP patients. THe abnormal noradrenaline reaction can change over time as can the pain relieving effects of sympatholytic therapy.
-
J Pain Symptom Manage · Oct 1995
Case ReportsLong-term ketamine subcutaneous continuous infusion in neuropathic cancer pain.
Neuropathic cancer pain may be less responsive to opioids than other pain. Several studies suggest that N-methyl-D-aspartate (NMDA)-receptor antagonists could play a role in the treatment of neuropathic pain. Ketamine is an NMDA-receptor antagonist that is used as an anesthetic and has been suggested as a useful drug for neuropathic pain. ⋯ We describe a patient who developed neuropathic cancer pain unresponsive to opioid escalation and spinal administration of a combination of bupivacaine-morphine and was subsequently treated by subcutaneous continuous ketamine infusion. A starting dose of 150 mg/day provided good pain relief and a dramatic reduction of the oral morphine dose (from 5 g to 200 mg). A slow and progressive increase of ketamine and morphine dosage (400 mg and 200 mg by the subcutaneous route, respectively) continued to provide adequate pain relief after 13 months of therapy despite signs of progressive disease.