Evidence of slow and variable choice-stepping reaction time in cancer survivors with chemotherapy-induced peripheral neuropathy.

Abstract

Chemotherapy-induced peripheral neuropathy (CIPN) is reported to affect up to 70 % of cancer survivors. Despite evidence that CIPN-related impairments often translate into balance and mobility deficits, the effects on stepping and quality of gait, well-documented risk factors for falls, are unclear. (i) Establish choice-stepping reaction time (CSRT) performance in survivors with CIPN compared to young and older healthy controls and people with Parkinson's disease; (ii) document walking stability; (iii) investigate relationships between stepping and gait data to objective and patient-reported outcomes. 41 cancer survivors with CIPN (mean (SD) age: 60.8 (9.7) years) who were ≥3months post chemotherapy, performed tests of simple and inhibitory CSRT. Walking stability measures were derived from 3-D accelerometry data during the 6-minute walk test. CIPN was assessed using neurological grading and patient-reported outcome measures (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire in CIPN Questionnaire scale EORTC CIPN20). In both stepping tests, CIPN participants performed at the level of adults aged 10 years older and people with mild to moderate Parkinson's disease. Mean (SD) total stepping response times in both CSRT (1160 (190) milliseconds) and inhibitory CSRT (1191 (164) milliseconds) tests were not associated with objective neurological grading but were correlated with increased difficulty feeling the ground. Participants with lower-limb vibration sensation deficit had slower and more variable CSRT times. There were no associations between walking stability and objective measures of CIPN, and limited correlations with the EORTC-CIPN20. Cancer survivors with CIPN showed deficits in voluntary stepping responses and seemed to compensate for their sensory and motor deficits by walking slower to maintain stability. Objective and patient-reported outcomes of CIPN were correlated with slower and more variable stepping response times. Future studies should aim to identify the causes of the apparent premature decline in cognitive-motor function and develop remediating interventions.