European journal of pain : EJP
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Neuropathic pain is strongly associated with mood disorders like anxiety and depression. Corticotropin-releasing factor (CRF) plays a prominent role in these disorders as it is up-regulated in limbic structures such as the amygdala, upon experimentally induced neuropathy. This review discusses recent literature on the role of CRF in pain processing and highlights the amygdala as a potential hot spot in supraspinal descending pain control. ⋯ Here, CRFR2 can be recruited by either high (pharmacological) concentrations of CRF or by endogenous CRFR2 ligands, the urocortins, leading to analgesia (pain termination). This on-off switching of pain is completed by redistribution of the CRF receptors to their initial activity state. We furthermore propose that in neuropathic pain, this mechanism is dysregulated and causes a state of permanent hyperalgesia, and present an integrative (patho)physiological model for the way disturbed CRF receptor signalling in the amygdala could initiate neuropathic pain.
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The aim of this review was to determine the impact of spinal cord stimulation (SCS) on physical function and sleep quality in individuals with failed back surgery syndrome (FBSS). This review comprised three phases: an electronic database search (PubMed, Cinahl Plus, EMBASE, PsychInfo, Pedro, Cochrane Library) identified potential papers; these were screened for inclusion criteria, with extraction of data from accepted papers and rating of internal validity by two independent reviewers using the Effective Public Health Practice Project quality assessment tool, a tool designed to assess non-RCTs (randomized controlled trials) as well as RCTs. Strength of the evidence was rated using the Agency for Health Care Policy and Research guidelines. ⋯ Improvements in sleep quantity, a reduction in awakenings and a decrease in sleep medication use were also noted (level D). The impact of SCS on cognitive function, i.e., memory and concentration, was also assessed using the same search strategy, no papers fulfilled the inclusion criteria for this study. Spinal cord stimulation effectively addressed many physical function and sleep problems associated with FBSS; however, there is a need for further high-quality objective investigations to support this.