Pain mechanisms in complex regional pain syndrome: a systematic review and meta-analysis of quantitative sensory testing outcomes.

BACKGROUND: Complex regional pain syndrome (CRPS) is a chronic condition following inciting events such as fractures or surgeries with sensorimotor and autonomic manifestations and poor prognosis. This review aimed to provide conclusive evidence about the sensory phenotype of CRPS based on quantitative sensory testing (QST) to understand the underlying pain mechanisms and guide treatment strategies. DATABASES: Eight databases were searched based on a previously published protocol. Forty studies comparing QST outcomes (thermal, mechanical, vibration, and electric detection thresholds, thermal, mechanical, pressure, and electric pain thresholds, wind-up ratio, mechanical pain sensitivity, allodynia, flare area, area after pinprick hyperalgesia, pleasantness after C-tactile stimulation, and pain ratings) in chronic CRPS (adults and children) versus healthy controls were included. RESULTS: From 37 studies (14 of low quality, 22 of fair quality, and 1 of good quality), adults with CRPS showed: (i) significant loss of thermal, mechanical, and vibration sensations, significant gain of thermal and mechanical pain thresholds, significant elevation of pain ratings, and no difference in wind-up ratio; (ii) significant reduction of pleasantness levels and increased area of pinprick hyperalgesia, in the affected limb. From three fair-quality studies, adolescents and children with CRPS showed loss of cold detection with cold hyperalgesia in the affected limb. There was moderate to substantial overall heterogeneity. CONCLUSION: Diffuse thermal and mechanical hypoesthesia with primary and secondary hyperalgesia, enhanced pain facilitation evidenced by increased area of pinprick hyperalgesia, and elevated pain ratings are dominant in adults with CRPS. Adolescents and children with CRPS showed less severe sensory abnormalities.

Head and shoulder functional changes in flutists.

AIMS: This study aimed at comparing head posture, symmetry of shoulder muscle strength, and posture among developing flutists, professional flutists, and a matched control group of singers. METHODS: Measurements of head and scapular posture and muscle strength were compared between flutists with ≤10 yrs of practice (developing flutists, n=9), flutists with >10 years of practice (professional flutists, n=9), and singers (n=9). Posture was measured with a goniometer and tape measure; strength was assessed with an isokinetic dynamometer. RESULTS: Significant differences were found between groups concerning forward head posture only; developing flutists showed a higher forward head posture compared to the other two groups (p<0.05). No significant differences were found for scapular posture or muscle strength. CONCLUSIONS: Developing flutists showed significantly more forward head posture. This finding supports the need to revise existing music curricula targeting the inclusion of compulsory disciplines on music medicine.