Pain
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Randomized Controlled Trial Comparative Study Clinical Trial
Is successful rehabilitation of complex regional pain syndrome due to sustained attention to the affected limb? A randomised clinical trial.
In complex regional pain syndrome (CRPS1) initiated by wrist fracture, a motor imagery program (MIP), consisting of hand laterality recognition followed by imagined movements and then mirror movements, reduces pain and disability, but the mechanism of effect is unclear. Possibilities include sustained attention to the affected limb, in which case the order of MIP components would not alter the effect, and sequential activation of cortical motor networks, in which case it would. Twenty subjects with chronic CRPS1 initiated by wrist fracture and who satisfied stringent inclusion criteria, were randomly allocated to one of three groups: hand laterality recognition, imagined movements, mirror movements (RecImMir, MIP); imagined movements, recognition, imagined movements (ImRecIm); recognition, mirror movements, recognition (RecMirRec). ⋯ Imagined movements imparted a further reduction in pain and disability, but only if they followed hand laterality recognition. Mirror movements also imparted a reduction in pain and disability, but only when they followed imagined movements. The effect of the MIP seems to be dependent on the order of components, which suggests that it is not due to sustained attention to the affected limb, but is consistent with sequential activation of cortical motor networks.
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Effective verbalization of pain requires progressive cognitive development and acquisition of social communication skills. Use of self-report in pediatric pain assessment assumes children have acquired a capacity to understand and use common words to describe pain. The current investigation documented the language most commonly used by young children to describe pain and the age of onset of use of these words. ⋯ The word-stem 'pain' was used relatively infrequently and gradually emerged in children's vocabularies. The findings indicate that young children rely on a select number of words to describe pain, with these words appearing in children's vocabularies at an early age. These results have implications for developmentally appropriate pain assessment in young children.
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Electrical tooth stimulation was used to investigate whether humans develop tolerance to nitrous oxide (N(2)O) analgesia within a single administration as well as over repeated administrations. In a double-blind cross-over experiment, 77 subjects received a 40-min administration of 38% N(2)O at one session and placebo gas at the other. The sessions were separated by 1 week and the order of gas administration was counterbalanced. ⋯ For both detection and pain threshold measures, acute tolerance developed during the initial N(2)O exposure and chronic tolerance developed over repeated administrations. Although chronic tolerance developed, a test for Pavlovian drug conditioning found no evidence of conditioned effects on sensory thresholds. In conclusion, acute and chronic tolerance develop to N(2)O's analgesic effects in humans.
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Multicenter Study Comparative Study
Comparison of pain syndromes associated with nervous or somatic lesions and development of a new neuropathic pain diagnostic questionnaire (DN4).
Few studies have directly compared the clinical features of neuropathic and non-neuropathic pains. For this purpose, the French Neuropathic Pain Group developed a clinician-administered questionnaire named DN4 consisting of both sensory descriptors and signs related to bedside sensory examination. This questionnaire was used in a prospective study of 160 patients presenting with pain associated with a definite neurological or somatic lesion. ⋯ The analysis of the psychometric properties of the DN4 questionnaire included: face validity, inter-rater reliability, factor analysis and logistic regression to identify the discriminant properties of items or combinations of items for the diagnosis of neuropathic pain. We found that a relatively small number of items are sufficient to discriminate neuropathic pain. The 10-item questionnaire developed in the present study constitutes a new diagnostic instrument, which might be helpful both in clinical research and daily practice.
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Predictors of outcome following whiplash injury are limited to socio-demographic and symptomatic factors, which are not readily amenable to secondary and tertiary intervention. This prospective study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds, brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK, IES) were measured in 76 acute whiplash participants. ⋯ Higher initial NDI score (1.03-1.28), greater psychological distress (GHQ-28) (1.04-1.28) and decreased ROM (1.03-1.25) predicted subjects with persistent milder symptoms from those who fully recovered. These results demonstrate that both physical and psychological factors play a role in recovery or non-recovery from whiplash injury. This may assist in the development of more relevant treatment methods for acute whiplash.