Browse by Audience
Consultation-based reassurance for patients with low back pain (LBP) in primary care has been shown to be associated with patients' outcomes. Little is known about the role of reassurance in people with LBP consulting with orthopaedic spinal care teams. Reassurance may be important, especially in cases where surgery is not indicated and patients are discharged without treatment.
Learn More >Experimental and clinical studies suggest that the low-affinity N-methyl-d-aspartate (NMDA) receptor open-channel blockers Mg and memantine are effective in reducing trigeminal nociceptive activation. The aim of the present study was to investigate the apparent effectiveness of these channel blockers using a model of trigeminal activation in vivo. Rats were anesthetized before electrically stimulating the dura mater adjacent the middle meningeal artery. Neurons responding to stimulation were recorded extracellularly using electrophysiological methods while l-glutamate or NMDA and Mg , memantine, or sodium controls were applied locally using microiontophoresis. Microiontophoretic application of Mg or memantine into the trigeminocervical complex inhibited mechanically and electrically-stimulated craniovascular afferent, l-glutamate, or NMDA-evoked neuronal activity at the second order trigeminal synapse of craniovascular afferents. By contrast, intravenous administration of MgSO (100 mg/kg) or memantine (10 mg/kg) did not significantly affect electrically-stimulated afferent-evoked activity within the trigeminocervical complex. The Mg and memantine concentrations achieved after systemic administration may not effectively inhibit activation of the trigeminocervical complex, perhaps providing an explanation for the relatively poor efficacy of these NMDA receptor open-channel blockers for headache treatment in clinical studies. Nevertheless, the present results suggest blocking of NMDA-receptor open channels inhibits nociceptive activation of the trigeminocervical complex. Further exploration of such channel blockers as a therapeutic strategy for primary head pain is warranted. This article is protected by copyright. All rights reserved.
Learn More >Nocebo hyperalgesia (i.e., increased pain sensitivity based on expectations) can be induced by conditioning, but is supposed to be mediated by conscious expectation. Although recent evidence points to the feasibility of subliminal conditioning of nocebo hyperalgesia with masked faces, face processing might be a special case and the practical implications of subliminal conditioning remain questionable. This study aimed to implicitly condition nocebo hyperalgesia using supraliminal cues.
Learn More >Temporomandibular joint osteoarthritis (TMJOA) is a prevalent source of temporomandibular joint disorder (TMD). Women are more commonly diagnosed with TMD and are more likely to seek care at tertiary orofacial pain clinics. Limited knowledge regarding mechanisms underlying temporomandibular joint (TMJ) pain impairs development of improved pain management strategies. In a rat model of unilateral TMJOA, monosodium iodoacetate (MIA) produces joint pathology in a concentration-dependent manner. Unilateral MIA produces alterations in meal patterns in males and females without altering overnight time spent eating or weight across 2 weeks. Monosodium iodoacetate (80 mg/mL)-treated males develop ongoing pain within 2 weeks after MIA injection. Females develop ongoing pain at a 5-fold lower MIA concentration (16.6 mg/m). Monosodium iodoacetate (80 mg/mL)-treated males show spread of tactile hypersensitivity across the face during the first week after injection and then to the fore paws and hind paws during the second week after injection, indicating development of central sensitization. At the lower dose, female rats demonstrate a similar spread of tactile hypersensitivity, whereas male rats do not develop ongoing pain or spread of tactile hypersensitivity outside the area of the ipsilateral temporomandibular joint. These observations indicate that females have a higher susceptibility to development of ongoing pain and central sensitization compared with male rats that is not due to differences in MIA-induced joint pathology. This model of TMJOA pain can be used to explore sex differences in pain processes implicated in development of neuropathic pain, ongoing pain, and central sensitization, allowing for development of individualized strategies for prevention and treatment of TMD joint pain.
Learn More >Chronic pain is extremely prevalent in older adults and is associated with significant morbidity, including limited mobility, social isolation, and depressed mood. Pain is defined by a biopsychosocial model highlighting the importance of a multidisciplinary approach to treatment, including multimodal medications, selected interventions, physical therapy and rehabilitation, and psychological treatments. In this narrative review, the authors highlight the use of these approaches in older adults with specific attention paid to considerations unique to aging, including alterations in drug metabolism, avoidance of polypharmacy, and physiologic changes predisposing to painful conditions.
Learn More >To measure and compare the total and normalised tibial nerve movements during forward bending in patients with and without failed back surgery syndrome (FBSS) and persistent leg pain following anatomically successful lumbar decompression surgery and demonstrated no psychological stress. Nerve pathomechanics may contribute to FBSS with persistent leg pain following anatomically successful lumbar decompression surgery.
Learn More >Cluster headache is the most severe primary headache disorder. A genetic basis has long been suggested by family and twin studies; however, little is understood about the genetic variants that contribute to cluster headache susceptibility.
Learn More >The aim of this study was to determine whether post-traumatic stress disorder (PTSD) moderates treatment outcomes in Acceptance and Commitment Therapy for chronic pain.
Learn More >Celecoxib is an NSAID commonly used to treat pain conditions in humans. In addition to its blocking activity on COXs enzymes, several other targets could contribute to its analgesic activity. Here we explore the spinal antinociceptive actions of celecoxib and the potential implication of K7 channels in mediating its effects. Spinal cord in vitro preparations from hind paw-inflamed animals were used to assess the segmental sensory-motor and the early sensory processing of nociceptive information. Electrophysiological recordings of ventral roots and dorsal horn neurones were obtained and the effects of celecoxib and K7 modulators on responses to repetitive dorsal root stimulation at C-fibre intensity were assessed. Celecoxib applied at clinically relevant concentrations produced depressant effects on responses to dorsal root stimulation recorded from both ventral roots and individual dorsal horn neurones, in contrast the non-nociceptive monosynaptic reflex was unaffected. The NSAID indomethacin was devoid of effect on spinal reflexes, but further co-application of celecoxib still produced depressant effects. The depressant actions of celecoxib were abolished after K7 channel blockade and mimicked by its structural analogue dimethyl-celecoxib that lacks COX blocking activity. The present results identify K7 channels as novel central targets for celecoxib that may be relevant to its analgesic effect. This finding contributes to better understand the pharmacology of celecoxib, and reinforces both the role of K7 channels in modulating the excitability of central pain pathways and its validity as target for the design of analgesics. SIGNIFICANCE STATEMENT: N/A.
Learn More >Regular or frequent use of analgesics and acute antimigraine drugs can increase the frequency of headache, and induce the transition from episodic to chronic headache or medication overuse headache. The 1-year prevalence of this condition in the general population is between 1% and 2%. Medication overuse headache is more common in women and in people with comorbid depression, anxiety, and other chronic pain conditions. Treatment of medication overuse headache has three components. First, patients need education and counselling to reduce the intake of medication for acute headache attacks. Second, some patients benefit from drug withdrawal (discontinuation of the overused medication). Finally, preventive drug therapy and non-medical prevention might be necessary in patients at onset of treatment or in patients who do not respond to the first two steps. The optimal therapeutic approach requires validation in controlled trials.
Learn More >