Pain
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Multicenter Study
Determining behavioural and physiological responses to pain in infants at risk for neurological impairment.
Multiple researchers have validated indicators and measures of infant pain. However, infants at risk for neurologic impairment (NI) have been under studied. Therefore, whether their pain responses are similar to those of other infants is unknown. ⋯ A significant Phase effect for low/high frequency Heart Rate Variability (HRV) ratio (F(2,216)=4.97, p=0.008) was found with the greatest decrease in Cohort A. Significant Cohort by Phase interactions existed for low and high frequency HRV. All infants responded to the most painful phase of the heel lance; however, infants at moderate and highest risk for NI exhibited decreased responses in some indicators.
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Randomized Controlled Trial
Analgesic action of gabapentin on chronic pain in the masticatory muscles: a randomized controlled trial.
Chronic masticatory myalgia (CMM) can be defined as constant pain in the masticatory muscles for more than 6 months and is influenced by the central nervous system. The antiepileptic agent gabapentin acts centrally and is used for managing different types of chronic pain conditions. The objective of this study was to evaluate the analgesic action of gabapentin on CMM. ⋯ Thirty-six patients completed the study. Gabapentin showed to be clinically and statistically superior to placebo in reducing pain reported by patients (gabapentin=51.04%; placebo=24.30%; P=0.037), masticatory muscle hyperalgesia (gabapentin=67.03%; placebo=14.37%; P=0.001) and impact of CMM on daily functioning (gabapentin=57.70%; placebo=16.92%; P=0.022). It can be concluded from this study that gabapentin is effective for the management of CMM.
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The Tampa scale for kinesiophobia (TSK) was developed to measure fear of movement/(re)injury in chronic pain patients. Although studies of the Dutch adaptation of the TSK have identified fear of movement/(re)injury as an important predictor of chronic pain, pain-related avoidance behaviour, and disability, surprisingly little data on the psychometric properties of the original English version of the TSK are available. The present study examined the reliability, construct validity and factor structure of the TSK in a sample of chronic pain patients (n=200) presenting for an interdisciplinary functional restoration program. ⋯ The TSK was not related to individual differences in physical performance testing as assessed using standardised treadmill and lifting tasks. Confirmatory factor analyses suggest that the TSK is best characterized by a three-factor trait method model that includes all 17 of the original scale items and takes into account the distinction between positively and negatively keyed items. The results of the present study provide important details regarding the psychometric properties of the original English version of the TSK and suggest that it may be unnecessary to remove the negatively keyed items in an attempt to improve scale validity.
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The analgesic effects of local administration of opioid agonists into peripheral tissues in alleviating pain have been well documented in both clinical and preclinical studies, although few studies have examined their effects in neuropathic pain. In this study, we investigated the anti-allodynic effects of peripherally acting delta opioid receptor (DOR) agonists in a rat model of neuropathic pain. Peripheral nerve injury (PNI) produced a time-dependent decrease in mechanical withdrawal thresholds that was attenuated by local administration into the hind paw of either morphine or the DOR agonist deltorphin II. ⋯ Results obtained from immunohistochemical studies confirmed up-regulation in small and large DRG neurons in neuropathic compared to sham animals. Additionally, there was an increase in DOR protein within the ipsilateral sciatic nerve of neuropathic animals compared to sham and contralateral neuropathic conditions indicating the occurrence of receptor trafficking to the site of injury. Taken together, our findings suggest that functional peripheral DORs are present in sensory neurons following PNI and validate the development of selective DOR agonists for alleviating neuropathic pain.