Pain
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Randomized Controlled Trial
Effects of a T-type calcium channel blocker, ABT-639, on spontaneous activity in C-nociceptors in patients with painful diabetic neuropathy: a randomized controlled trial.
T-type calcium channels are a potential novel target for treatment of neuropathic pain such as painful diabetic neuropathy. ABT-639 is a peripherally acting highly selective T-type Ca(v)3.2 calcium channel blocker that has demonstrated analgesic efficacy in preclinical models and may have the potential to reduce spontaneous fiber activity. Microneurography is a unique technique that directly assesses the function of peripheral sensory afferents and measures abnormal spontaneous activity in single peripheral nociceptive C fibers. ⋯ Further research of T-type Ca(v)3.2 calcium channels as potential treatment targets for painful diabetic neuropathy is warranted. The utilization of microneurography as a means to measure abnormal activity in C-nociceptors in human clinical studies opens new possibilities for future studies of compounds targeting peripheral nerve hyperexcitability. ClinicalTrials.gov identifier: NCT01589432.
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Randomized Controlled Trial
Analgesic and anti-hyperalgesic effects of melatonin in a human inflammatory pain model: a randomized, double-blind, placebo-controlled, three-arm crossover study.
Antinociceptive effects of melatonin have been documented in a wide range of experimental animal models. The aim of this study was to investigate the analgesic, antihyperalgesic, and anti-inflammatory properties of melatonin using a validated burn injury (BI) model in healthy male volunteers. The design was a randomized, double-blind, placebo-controlled, three-arm crossover study. ⋯ While the BI induced large secondary hyperalgesia areas and significantly increased the markers of inflammation, no significant effects of melatonin were observed with respect to primary or secondary outcomes, compared with placebo. The administration of melatonin was not associated with any adverse effects. Melatonin did not demonstrate any analgesic, antihyperalgesic, or anti-inflammatory properties in the BI model.
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Randomized Controlled Trial
High and low frequency transcutaneous electrical nerve stimulation (TENS) does not reduce experimental pain in elderly individuals.
Despite its widespread clinical use, the efficacy of transcutaneous electrical nerve stimulation (TENS) remains poorly documented in elderly individuals. In this randomized, double-blind crossover study, we compared the efficacy of high-frequency (HF), low-frequency (LF), and placebo (P) TENS in a group of 15 elderly adults (mean age: 67 ± 5 years). The effect of HF-, LF-, and P-TENS was also evaluated in a group of 15 young individuals (26 ± 5 years; same study design) to validate the effectiveness of the TENS protocols that were used in the elderly group. ⋯ High-frequency, LF-, and P-TENS all increased pain thresholds in young individuals, whereas in older individuals, only LF-TENS increased pain thresholds. Taken together, these results suggest that TENS is effective in young, but not in older, individuals. Future studies should be conducted to confirm these results in pain populations and to identify strategies that could enhance the effect of TENS in the elderly.
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Randomized Controlled Trial
Altered Pain Modulation in Patients with Persistent Post-Endodontic Pain.
Persistent pain may follow nerve injuries associated with invasive therapeutic interventions. About 3% to 7% of the patients remain with chronic pain after endodontic treatment, and these are described as suffering from painful posttraumatic trigeminal neuropathy (PTTN). Unfortunately, we are unable to identify which patients undergoing such procedures are at increased risk of developing PTTN. ⋯ The dynamic sensory testing demonstrated less efficient conditioned pain modulation, suggesting reduced function of the inhibitory endogenous pain-modulatory system, in patients with PTTN, mainly in those suffering from the condition for more than a year. The static sensory testing of patients with PTTN demonstrated forearm hyperalgesia to mechanical stimulation mainly in patients suffering from the condition for less than a year and prolonged painful sensation after intraoral cold stimulus mainly in patients suffering from the condition for more than a year. These findings suggest that PTTN is associated more with the inhibitory rather than the facilitatory arm of pain modulation and that the central nervous system has a role in PTTN pathophysiology, possibly in a time-dependent fashion.
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Randomized Controlled Trial
The Pain Course: A Randomised Controlled Trial Examining an Internet-Delivered Pain Management Program when Provided with Different Levels of Clinician Support.
The present study evaluated an internet-delivered pain management program, the Pain Course, when provided with different levels of clinician support. Participants (n = 490) were randomised to 1 of 4 groups: (1) Regular Contact (n = 143), (2) Optional Contact (n = 141), (3) No Contact (n = 131), and (4) a treatment-as-usual Waitlist Control Group (n = 75). The treatment program was based on the principles of cognitive behaviour therapy and comprised 5 internet-delivered lessons provided over 8 weeks. ⋯ High treatment completion rates and levels of satisfaction were reported, and no marked or consistent differences were observed between the Treatment Groups. The mean clinician time per participant was 67.69 minutes (SD = 33.50), 12.85 minutes (SD = 24.61), and 5.44 minutes (SD = 12.38) for those receiving regular contact, the option of contact, and no clinical contact, respectively. These results highlight the very significant public health potential of carefully designed and administered internet-delivered pain management programs and indicate that these programs can be successfully administered with several levels of clinical support.