Pain
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Randomized Controlled Trial Comparative Study
Iontophoretic administration of S(+)-ketamine in patients with intractable central pain: a placebo-controlled trial.
The efficacy of 50 and 75 mg S(+)-ketamine administered daily by an iontophoresis-assisted transdermal drug delivery system was tested against placebo in a randomized, double-blind design in 33 patients with central neuropathic pain. At baseline and 1 week after the start of treatment subjects were evaluated with standard measures of efficacy: pain intensity measured by visual analog scale (VAS), health status (Pain Disability Index and EQ-5D) and quality of life (SF-36). Safety assessment included incidence and intensity of adverse events. ⋯ Iontophoretic administration of S(+)-ketamine was well tolerated with a low incidence of adverse events (mild and transient in nature, resolving spontaneously). Iontophoretic administration of S(+)-ketamine was not more effective than placebo treatment in reducing pain scores in patients with severe central neuropathic pain. However, iontophoretic administration of 75 mg S(+)-ketamine improved the health status and the quality of life in these patients.
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Comparative Study
Motor cortex stimulation for refractory neuropathic pain: four year outcome and predictors of efficacy.
Thirty-one patients with medically refractory neuropathic pain were included in a prospective evaluation of motor cortex stimulation. The long-term outcome was evaluated using five variables: (a) rate (percentage) of pain relief, (b) pain scores as assessed on VAS, (c) postoperative decrease in VAS scores, (d) reduction in analgesic drug intake, (e) a dichotomic (yes/no) response to the question whether the patient would accept, under similar circumstances, to be operated on again. Pain relief was rated as excellent (>70 % pain relief) in 10 % of cases, good (40-69 %) in 42 %, poor (10-39 %) in 35 % and negligible (0-9 %) in 13 %. ⋯ Neither preoperative motor status, pain characteristics, type or localisation of lesions, quantitative sensory testing, Somatosensory Evoked Potentials, nor the interval between pain and surgery were found to predict the efficacy of MCS. The level of pain relief, as evaluated in the first month following implantation was a strong predictor of long-term relief (regression analysis, R=0.744; p<0.0001). These results confirm that MCS can be a satisfactory and durable alternative to medical treatments in patients with refractory pain, and suggest that the efficacy of MCS may be predicted in the first month of therapy.
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Evidence has been accumulated suggesting that a dysfunction in pain inhibitory systems, i.e. in 'diffuse noxious inhibitory controls' (DNIC)-like mechanisms, might be-amongst other factors-responsible for the development of anatomically generalized chronic pain like fibromyalgia. The aim of the present study was to look for similar impairments in chronic tension-type headache (CTTH) as a regionally specific pain syndrome. Twenty-nine CTTH patients and 25 age- and sex-matched healthy control subjects participated in the study. ⋯ This group difference was present during the 'pain' as well as the 'heat' condition. Furthermore, the electrical detection and pain thresholds were affected in this group-specific manner both at the forearm and at the temple. These findings suggest that patients with CTTH suffer from deficient DNIC-like pain inhibitory mechanisms in a similar manner, as do patients with anatomically generalized chronic pain like fibromyalgia.
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Randomized Controlled Trial Comparative Study
Botulinum toxin A versus bupivacaine trigger point injections for the treatment of myofascial pain syndrome: a randomised double blind crossover study.
The treatment of myofascial pain syndrome (MPS) is diverse and includes trigger point injections of various substances including local anesthetics, steroids and Botulinum toxin A (BTX A). The purpose of this study was to compare the effectiveness of trigger point injections using BTX A versus bupivacaine, both in combination with a home-based rehabilitation program. To be enrolled, subjects first had to demonstrate responsiveness to bupivacaine trigger point injection. ⋯ Both treatments were effective in reducing pain when compared to baseline (P=0.0067). There was, however, no significant difference between the BTX A and 0.5% bupivacaine groups in duration or magnitude of pain relief, function, satisfaction or cost of care (cost of injectate excluded). Considering the high cost of BTX A, bupivacaine is deemed a more cost-effective injectate for MPS.