Pain
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Severe neuropathic pain is a hallmark of Fabry disease, a genetic disorder caused by a deficiency in lysosomal α-galactosidase A. Pain experienced by these patients significantly impacts their quality of life and ability to perform everyday tasks. Patients with Fabry disease suffer from peripheral neuropathy, sensory abnormalities, acute pain crises, and lifelong ongoing pain. ⋯ This review will detail the types of pain, sensory abnormalities, influence of demographics on pain, and current strategies to treat pain experienced by patients with Fabry disease. In addition, we discuss the current knowledge of Fabry pain pathogenesis and which aspects of the disease preclinical models accurately recapitulate. Understanding the commonalities and divergences between humans and preclinical models can be used to further interrogate mechanisms causing the pain and sensory abnormalities as well as advance development of the next generation of therapeutics to treat pain in patients with Fabry disease.
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The development of new analgesic drugs has been hampered by the inability to translate preclinical findings to humans. This failure is due in part to the weak connection between commonly used pain outcome measures in rodents and the clinical symptoms of chronic pain. Most rodent studies rely on the use of experimenter-evoked measures of pain and assess behavior under ethologically unnatural conditions, which limits the translational potential of preclinical research. ⋯ Noxious stimuli reduced hanging behavior in an intensity-dependent manner, and the reduction in hanging could be restored by analgesics. Finally, we developed an automated approach to assess hanging behavior. Collectively, our results indicate that the depression of hanging behavior is a novel, ethologically valid, and translationally relevant pain outcome measure in mice that could facilitate the study of pain and analgesic development.
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Randomized Controlled Trial
Open-label placebo for chronic low back pain: a 5-year follow-up.
Long-term follow-up of patients treated with open-label placebo (OLP) are nonexistent. In this article, we report a 5-year follow-up of a 3-week OLP randomized controlled trial (RCT) in patients with chronic low back pain. We recontacted the participants of original RCT and reassessed their pain, disability, and use of pain medication. ⋯ By contrast, the use of alternative approaches to pain management increased (from 18% to 29%). Although the reduction in pain and medication is comparable with the improvements that occurred in the original study, a major limitation of this long-term follow-up is the absence of controls for spontaneous improvement and new cointerventions. Nonetheless, our data suggest that reductions in pain and disability after OLP may be long lasting.
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Multicenter Study
Hippocampus shape deformation: potential diagnostic biomarker for chronic back pain in women.
Sex differences in the quality and prevalence of chronic pain are manifold, with women generally presenting higher incidence and severity. Uncovering chronic pain-related sex differences inform neural mechanisms and may lead to novel treatment routes. In a multicenter morphological study (total n = 374), we investigated whether the shape of subcortical regions would reflect sex differences in back pain. ⋯ Weeks after onset of back pain, there was no deformation within alHP, but at 1 and 3 years women exhibited a trend for outer deformation. The alHP partly overlapped with the subiculum and entorhinal cortex, whose functional connectivity, in healthy subjects, was associated with emotional and episodic memory related terms (Neurosynth, reverse inference). These findings suggest that in women the alHP undergoes anatomical changes with pain persistence, highlighting sexually dimorphic involvement of emotional and episodic memory-related circuitry with chronic pain.