ABSTRACT
While current data suggest that all referred pain derives from common mechanisms of central sensitisation, there is a paucity of data directly comparing referral in different limbs. Does a common mechanism result in similar precepts of referral from similar stimuli in different limbs? We tested the hypothesis that, in a given subject, the incidence, intensity and spatiotemporal expression of referred pain are similar during the muscle pain induced by bolus intramuscular injection of hypertonic saline into flexor carpi radialis (FCR) and tibialis anterior (TA). We also tested the hypothesis that an increase in stimulus intensity causes a parallel increase in the incidence and intensity of local and referred pain, by comparing the responses to 5 and 10 % hypertonic saline in two groups of subjects. 29 subjects mapped areas of local and referred pain, rating intensities on a visual analogue scale every 30 s until the cessation of pain. Following an injection of 5 % hypertonic saline into TA, 86 % of subjects who had previously reported referred pain (or its absence) in the hand during FCR pain reported referred pain (or its absence) in the foot. Following an injection of the 10 % solution, 67 % of subjects reported a pattern in the lower limb that was the same as that seen in the upper limb. We conclude that the expression of referred pain is largely consistent in widely separated limb segments in individual subjects and is largely dependent on inter-subject differences. This may have implications for the development of chronic pain following an acute episode of pain.
Subject(s)
Musculoskeletal Pain/physiopathology , Pain, Referred/physiopathology , Acute Disease , Adolescent , Adult , Analysis of Variance , Arm , Data Interpretation, Statistical , Electric Stimulation , Female , Foot , Forecasting , Hand , Humans , Individuality , Leg , Male , Models, Anatomic , Musculoskeletal Pain/chemically induced , Pain Measurement , Psychophysics , Saline Solution, Hypertonic , Young AdultABSTRACT
BACKGROUND AND OBJECTIVE: In systematic reviews of the reliability of diagnostic tests, no quality assessment tool has been used consistently. The aim of this study was to develop a specific quality appraisal tool for studies of diagnostic reliability. METHODS: Key principles for the quality of studies of diagnostic reliability were identified with reference to epidemiologic principles, existing quality appraisal checklists, and the Standards for Reporting of Diagnostic Accuracy (STARD) and Quality Assessment of Diagnostic Accuracy Studies (QUADAS) resources. Specific items that encompassed each of the principles were developed. Experts in diagnostic research provided feedback on the items that were to form the appraisal tool. This process was iterative and continued until consensus among experts was reached. RESULTS: The Quality Appraisal of Reliability Studies (QAREL) checklist includes 11 items that explore seven principles. Items cover the spectrum of subjects, spectrum of examiners, examiner blinding, order effects of examination, suitability of the time interval among repeated measurements, appropriate test application and interpretation, and appropriate statistical analysis. CONCLUSIONS: QAREL has been developed as a specific quality appraisal tool for studies of diagnostic reliability. The reliability of this tool in different contexts needs to be evaluated.
