Pain
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In the present study the question was addressed whether sensitivity to experimental pain stimuli differs between families, which are previously characterized by the degree of cold tolerance (very insensitive or very sensitive) of one family member. A total of 232 healthy medical students were screened for cold pain tolerance employing a cold pressor test. Subsequently 50 of them were investigated in detail under laboratory conditions. ⋯ The other variables, including the COMT polymorphism, were not related to cold pain tolerance in our study. In conclusion our results suggest that cold pain tolerance may be at least partially inherited. Genetic or environmental factors might explain family clustering of cold pain sensitivity.
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Review Meta Analysis
Hypoalgesia in schizophrenia is independent of antipsychotic drugs: a systematic quantitative review of experimental studies.
Diminished sensitivity to pain in schizophrenia has been reported since the early works of Bleuler [Bleuler E. Textbook of psychiatry (trans. Brill HA, 1951). ⋯ This meta-analysis substantiates the hypothesis of a diminished pain response in schizophrenia. The study also suggests that hypoalgesia in schizophrenia cannot be solely explained by the effects of antipsychotic drugs, and that it may not be a pain-specific blunted response. Further studies are warranted to determine the clinical and biological correlates, and the social and health consequences, of hypoalgesia in schizophrenia.
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The aim of this cross-sectional study was to examine the prevalence and correlates of pharmacotherapy for current daily pain in older home care clients, focusing on analgesic type and potential contraindications to treatment. The sample included 2779 clients aged 65+years receiving services from Community Care Access Centres in Ontario during 1999-2001. Clients were assessed with the Resident Assessment Instrument-Home Care (RAI-HC). ⋯ Clients with congestive heart failure and without a diagnosis of arthritis were significantly less likely to receive a non-opioid alone. A diagnosis of arthritis or cancer and use of nine or more medications were significantly associated with opioid use. The findings provide evidence of both rational prescribing practices and potential treatment bias in the pharmacotherapeutic management of daily pain in older home care clients.
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Surgical and medical procedures, mainly those associated with nerve injuries, may lead to chronic persistent pain. Currently, one cannot predict which patients undergoing such procedures are 'at risk' to develop chronic pain. We hypothesized that the endogenous analgesia system is key to determining the pattern of handling noxious events, and therefore testing diffuse noxious inhibitory control (DNIC) will predict susceptibility to develop chronic post-thoracotomy pain (CPTP). ⋯ For prediction of acute post-operative pain intensity, DNIC efficiency was not found significant. Effectiveness of the endogenous analgesia system obtained at a pain-free state, therefore, seems to reflect the individual's ability to tackle noxious events, identifying patients 'at risk' to develop post-intervention chronic pain. Applying this diagnostic approach before procedures that might generate pain may allow individually tailored pain prevention and management, which may substantially reduce suffering.
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The mechanisms of nociception in the low back are poorly understood, partly because systematic recordings from dorsal horn neurons with input from the low back are largely missing. The purpose of this investigation was to (1) identify spinal segments and dorsal horn neurons receiving input from the low back, (2) test the effect of nerve growth factor (NGF) injected into the multifidus muscle (MF) on the neurons' responsiveness, and (3) study the influence of a chronic MF inflammation on the responses. In rats, microelectrode recordings were made in the segments L2, L3, and L5 to find dorsal horn neurons having input from the low back (LB neurons). ⋯ The centers of the neurons' receptive fields (RFs) were consistently located 2-3 segments caudally relative to their recording site. The results show that (1) input convergence from various tissues is common for LB neurons, (2) the input from structures of the low back is processed 2-3 segments cranially relative to the vertebral level of the RFs, and (3) the responsiveness of LB neurons is increased during a pathologic alteration of the MF. The above findings may be relevant for some cases of chronic low back pain in patients.