Pain
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A multisystem phenotype with the Triad of bodily pain, psychological distress, and sleep disturbance was found to have high risk for developing initial onset of painful temporomandibular disorders (TMDs) in the multicenter Orofacial Pain: Prospective Evaluation and Risk Assessment dataset. In this study, we systemically examined phenotypic characteristics and explored potential pathophysiology in quantitative sensory testing and autonomic nervous system domains in this multisystem Triad phenotype. Secondary analysis was performed on 1199 non-Triad and 154 Triad TMD-free Orofacial Pain: Prospective Evaluation and Risk Assessment enrollees at baseline. ⋯ These findings highlight the importance of whole-person multisystem assessment at the stage before developing complex pain conditions, such as TMDs, and suggest that, in addition to a "tissue damage monitor," pain should be considered in a broader context, such as a component within a "distress monitoring system" at the whole-person level when multisystem issues copresent. Therefore, the presence or absence of multisystem issues may carry critical information when searching for disease mechanisms and developing mechanism-based intervention and prevention strategies for TMDs and related pain conditions. Cardiovascular autonomic function should be further researched when multisystem issues copresent before developing TMDs.
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Interstitial cystitis/bladder pain syndrome (IC/BPS) is a common and debilitating disease with poor treatment outcomes. Studies from the multidisciplinary approach to the study of chronic pelvic pain research network established that IC/BPS patients with chronic overlapping pain conditions (COPCs) experience poorer quality of life and more severe symptoms, yet the neurobiological correlates of this subtype are largely unknown. We previously showed that ex vivo toll-like receptor 4 (TLR4) cytokine/chemokine release is associated with the presence of COPCs, as well as widespread pain and experimental pain sensitivity women with IC/BPS. ⋯ Controlling for patient age, body mass index, and site of collection, we found that greater ex vivo TLR4-stimulated cytokine/chemokine release was associated with the presence of COPCs ( P < 0.01), extent of widespread pain ( P < 0.05), but not experimental pain sensitivity ( P > 0.05). However, a second component of anti-inflammatory, regulatory, and chemotactic activity was associated with reduced pain sensitivity ( P < 0.01). These results confirm that the IC/BPS + COPCs subtype show higher levels of ex vivo TLR4 cytokine/chemokine release and support a link between immune priming and nociplastic pain in IC/BPS.
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Temporomandibular disorders (TMD) include a group of musculoskeletal disorders that may involve increased responsiveness of nociceptive neurons in the central nervous system (ie, central sensitization). To test this hypothesis further, this study examined whether, as compared with healthy subjects, patients with chronic TMD have a greater propensity to develop secondary mechanical hyperalgesia-a phenomenon that can be confidently attributed to central sensitization. In this case-control study, we assessed the area of secondary mechanical hyperalgesia induced experimentally by delivering high-frequency electrical stimulation (HFS) to the volar forearm skin in 20 participants with chronic TMD and 20 matched healthy controls. ⋯ Regarding secondary outcomes, there was no group difference in the intensity of secondary mechanical hyperalgesia, but allodynia to cotton after HFS was more frequent in the chronic TMD group. To the best of our knowledge, this is the first study to show that individuals with chronic TMD have an increased propensity to develop secondary hyperalgesia in a site innervated extratrigeminally. Our results contribute to a better understanding of the pathophysiology of chronic TMD.
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Complex regional pain syndrome (CRPS) is characterized by inflammation and a failure of multimodal signal integration in the central nervous system (CNS). Central nervous system reorganization might account for sensory deficits, pain, and motor symptoms in CRPS, but it is not clear how motor control is affected by CNS mechanisms. The present study characterized the motor performance and related cortical activity of 16 CRPS patients and 16 control participants during the planning of visually guided unimanual grips, in patients with either the unaffected left or the affected right hand, and investigated resting-state sensorimotor coupling in MRI. ⋯ Fear of movement or individual pain scores contributed only marginally to the observed effects. The study suggests that changes in planning-related sensorimotor CNS regions may explain difficulties with force exertion and motor control in CRPS. Perspective : Functional changes in motor planning-related brain regions might indicate that feedback-enhanced functional motor training may be effective for CRPS rehabilitation.
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Pain management for patients with dementia is challenging because many experience pain while being unable to communicate their pain. The aim of this study was to describe pain, pain management, and to perform a thorough clinical examination of chronic pain conditions among patients with dementia. Residents (n = 498) from 12 nursing homes were assessed for dementia (Clinical Dementia Rating scale [CDR]) and for pain with the Mobilization-Observation-Behavior-Intensity-Dementia-2 (MOBID-2) assessment form. ⋯ Chronic widespread pain was the most prevalent (14.5%) followed by nonspecific pain from the back (13.4%), whereas the most prevalent chronic secondary pain conditions were chronic pain caused by osteoarthritis (15.4%) and stroke (8.0%). One-fourth received opioids, which was significantly associated with severe pain ( P < 0.001) compared with moderate pain, although no significant association was found between opioid use and the type of pain condition. Although knowledge of the severity and specific types of pain conditions is recommended to direct the choice of treatment, these areas are not sufficiently explored in the nursing home populations with dementia and may hinder a better treatment of pain in this population.