Pain
-
Development and application of psychophysical test paradigms to assess endogenous pain modulation in healthy controls and in patients yielded large body of data over the last 2 decades. These tests can assist in predicting pain acquisition, in characterizing pain syndromes and related dysfunctions of pain modulation, and in predicting response to treatment. This chapter reviews the development of thought on pain modulation in the clinical setup, focusing on conditioned pain modulation, and update on accumulated data regarding the mechanism, protocols of administration, and applications in the clinic.
-
Neuropathic pain (NP) is a significant medical and socioeconomic burden. Epidemiological surveys have indicated that many patients with NP do not receive appropriate treatment for their pain. A number of pharmacological agents have been found to be effective in NP on the basis of randomized controlled trials including, in particular, tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitor antidepressants, pregabalin, gabapentin, opioids, lidocaine patches, and capsaicin high-concentration patches. ⋯ However, meta-analyses indicate that only a minority of patients with NP have an adequate response to drug therapy. Several reasons may account for these findings, including a modest efficacy of the active drugs, a high placebo response, the heterogeneity of diagnostic criteria for NP, and an inadequate classification of patients in clinical trials. Improving the current way of conducting clinical trials in NP could contribute to reduce therapeutic failures and may have an impact on future therapeutic algorithms.
-
Multicenter Study
Pain, agitation, and behavioural problems in people with dementia admitted to general hospital wards: a longitudinal cohort study.
Pain is underdetected and undertreated in people with dementia. We aimed to investigate the prevalence of pain in people with dementia admitted to general hospitals and explore the association between pain and behavioural and psychiatric symptoms of dementia (BPSD). We conducted a longitudinal cohort study of 230 people, aged above 70, with dementia and unplanned medical admissions to 2 UK hospitals. ⋯ The association was the strongest for aggression and anxiety. Pain was common in people with dementia admitted to the acute hospital and associated with BPSD. Improved pain management may reduce distressing behaviours and improve the quality of hospital care for people with dementia.
-
The objective of this study was to determine the effects of age, sex, and type of surgery on postoperative pain trajectories derived in a clinical setting from pain assessments in the first 24 hours after surgery. This study is a retrospective cohort study using a large electronic medical records system to collect and analyze surgical case data. The sample population included adult patients undergoing nonambulatory nonobstetric surgery in a single institution over a 1-year period. ⋯ Pain scores significantly decreased over time in all age groups, with a slightly more rapid decrease for younger patients. Pain trajectories differed by anatomic location of surgery, ranging from -0.054 (95% CI: -0.062 to -0.046) NRS units per hour for integumentary and nervous surgery to -0.104 (95% CI: -0.110 to -0.098) NRS units per hour for digestive surgery, and a positive trajectory (0.02 [95% CI: 0.016 to 0.024] NRS units per hour) for musculoskeletal surgery. Our data support the important role of time after surgery in considering the influence of biopsychosocial and clinical factors on acute postoperative pain.
-
The underlying mechanism of chronic pain is believed to be changes in excitability in spinal dorsal horn (DH) neurons that respond abnormally to peripheral input. Increased excitability in pain transmission neurons, and depression of inhibitory neurons, are widely recognized in the spinal cord of animal models of chronic pain. The possible occurrence of 2 parallel but opposing forms of synaptic plasticity, long-term potentiation (LTP) and long-term depression (LTD) was tested in 2 types of identified DH neurons using whole-cell patch-clamp recordings in mouse spinal cord slices. ⋯ Both the pattern and magnitude of intracellular Ca after ACS were almost identical between STTn and GABAn based on live-cell calcium imaging. The results suggest that the intense sensory input induces an NMDA receptor-dependent intracellular Ca increase in both STTn and GABAn, but produces opposing synaptic plasticity. This study shows that there is cell type-specific synaptic plasticity in the spinal DH.