European journal of pain : EJP
-
Slowing refers to the gradual decrease in conduction velocity evoked by repetitive electrical stimuli. The underlying mechanisms are still poorly understood, and its physiological/pathological relevance scarcely discussed; however, changes in axonal conduction properties might unmask abnormal nociceptor function and alter the encoding time window at the spinal cord. ⋯ Under our experimental conditions, slowing seems largely dependent on functional Ih . The marked decrease in slowing after axotomy in C-fibres fits with the increased expression of functional hyperpolarization-activated/HCN channel current and may underlie the analgesic effects of the specific Ih blocker ZD7288 previously described in neuropathic pain models.
-
Brain areas involved in nociception have been repeatedly investigated. Therefore, brain responses to physiological pain conditions are well identified. The same is not true for allodynic pain in patients with neuropathic pain since the cortical reorganizations that are involved in the conversion of non-noxious stimuli into painful sensations still remain unknown. ⋯ The insular subdivision was inappropriately activated considering the innocuous nature of the stimulus, but adequately activated with regard to pain-evoked sensation. Subcortically, the hypothesis of reorganization at any level of the somatosensory and pain pathways underlying such insular activity was supported by the observed shift of thalamic activation from a lateral-posterior to an anterior-medial position.
-
Randomized Controlled Trial
The role of excess subcutaneous fat in pain and sensory sensitivity in obesity.
Previous studies suggest pain sensitivity may be decreased in obesity, but it is unknown whether this is a global or a site-specific phenomenon related to the amount of excess fat. ⋯ Obese participants are less sensitive than non-obese individuals, but only on areas with excess subcutaneous fat.
-
The chronic pain grading (CPG), a standard approach to classify the severity of pain conditions in adults, combines the characteristics of pain intensity and pain-related disability. However, in children and adolescents, the CPG has only been validated in a school sample, but not in the actual target population, i.e., clinical populations with pain. ⋯ The CPG may be applied to adolescent tertiary care samples and to assess outcomes in clinical trials. However, in this study it was not appropriate to assign adolescent patients to different treatment options. Future work should focus on developing a comprehensive assessment tool for assigning patients to different treatments.
-
The role of quantitative sensory testing (QST) in prediction of analgesic effect in humans is scarcely investigated. This updated review assesses the effectiveness in predicting analgesic effects in healthy volunteers, surgical patients and patients with chronic pain. A systematic review of English written, peer-reviewed articles was conducted using PubMed and Embase (1980-2013). ⋯ Heterogeneity among studies was observed especially with regard to application of QST and type and use of analgesics. Although promising, the current evidence is not sufficiently robust to recommend the use of any specific QST parameter in predicting analgesic response. Future studies should focus on a range of different experimental pain modalities rather than a single static pain stimulation paradigm.