Nerve pressure pain hypersensitivity and upper limb mechanosensitivity in breast cancer survivors: A Case-Control Study

Abstract

Objective: This study aims to investigate the presence of bilateral pressure pain hypersensitivity in arm trunk nerves and upper limb mechanosensitivity in breast cancer patients with neck-shoulder pain after medical treatments. Methods: Twenty-two breast cancer survivors (mean age 49.05±7.8 years) and matched healthy controls (mean age 50.76±7.6 years) participated in the study. Neck and shoulder pain was evaluated using an 11-point numerical point rating scale. Pressure pain thresholds (PPTs) were bilaterally assessed over the median, radial, and ulnar nerve trunks and tibialis muscle, and the neurodynamics of the upper limb by neural tolerance to movement was evaluated in the median, radial, and ulnar nerves. Results: Thirteen (59.1%) patients reported spontaneous neck pain, and 16 (72.7%) patients showed spontaneous shoulder/axillary pain. Analysis of variance revealed that breast cancer survivors showed significant between-group but not between-side differences over the median nerve trunk (group: P=<0.001; side: P=0.146), radial nerve trunk (group: P=<0.001; side: P=0.300), ulnar nerve trunk (group: P=<0.001; side: P=0.744), and tibialis anterior muscle (group: P=<0.001; side: P=0.118). The patients also showed statistically significant differences in range of motion (ROM) between groups and between sides in ULNT1MEDIAN (group: P=<0.001; side: P=<0.001) and ULNTULNAR (group: P=0.009; side: P=0.002). The analysis did not show statistically significant differences in ROM between groups, but there was a statistical significance between sides for ULNTRADIAL (group: P=0.081; side: P=0.046). Conclusions: Breast cancer survivors present bilateral and widespread neural hypersensitivity, as they did in muscular tissue in previous studies. Breast cancer survivors demonstrate a reduction in ROM during ULNTs in the affected side.