Background: Chemotherapy-induced peripheral neuropathy (CIPN) can affect functional performance and quality of life considerably. Since balance training has proven to enhance physical function, it might be a promising strategy to manage CIPN-induced functional impairments.
Methods: Fifty cancer survivors with persisting CIPN after finishing their treatment were randomly allocated to an intervention (IG) or active control group (CG). The IG did endurance plus balance training, the CG only endurance training (twice weekly over 12 weeks). Pre- and post-assessments included functional performance, cardiorespiratory fitness, vibration sense, and self-reported CIPN symptoms (EORTC QLQ-CIPN20).
Results: Intention-to-treat analyses (n = 41) did not reveal a significant group difference (CG minus IG) for sway path in semi-tandem stance after intervention (primary endpoint), adjusted for baseline. However, our per-protocol analysis of 37 patients with training compliance ≥70% revealed: the IG reduced their sway path during semi-tandem stance (- 76 mm, 95% CI -141 - -17; CG: -6 mm, 95% CI -52 - 50), improved the duration standing on one leg on instable surface (11 s, 95% CI 8-17; CG: 0 s, 95%CI 0-5) and reported decreased motor symptoms (-8points, 95% CI -18 - 0; CG: -2points 95% CI -6 - 2). Both groups reported reduced overall- (IG: -10points, 95% CI -17 - -4; CG: -6points, 95% CI -11 - -1) and sensory symptoms (IG: -7points, 95% CI -15 - 0; CG: -7points, 95% CI -15 - 0), while only the CG exhibited objectively better vibration sense (knuckle: 0.8points, 95% CI 0.3-1.3; IG: 0.0points, 95% CI -1.1 - 0.9; patella: 1.0points, 95% CI 0.4-1.6: IG: -0.8points, 95% CI -0.2 - 0.0). Furthermore, maximum power output during cardiopulmonary exercise test increased in both groups (IG and CG: 0.1 W/kg, 95% CI 0.0-0.2), but only the CG improved their jump height (2 cm, 95% CI 0.5-3.5; IG: 1 cm, 95% CI -0.4 - 3.2).
Conclusion: We suppose that endurance training induced a reduction in sensory symptoms in both groups, while balance training additionally improved patients' functional status. This additional functional effect might reflect the IG's superiority in the CIPN20 motor score. Both exercises provide a clear and relevant benefit for patients with CIPN.
Trial registration: German Clinical Trials Register (DRKS) number: DRKS00005419 , prospectively registered on November 19, 2013.
Keywords: Neuromuscular adaptation; Peripheral nervous system diseases; Postural balance; Quality of life; Somatosensory disorders, exercise therapy.