Chemotherapy induced peripheral neurotoxicity (cipn) – beyond paresthesia and pain: the impact of sensory ataxia on quality of life

INTRODUCTION: we present a secondary analysis of the data set obtained in the previously published CI-PeriNomS study, aimed at standardizing outcome measures in Chemotherapy Induced Peripheral Neurotoxicity (CIPN). In this analysis we focus on sensory ataxia in order to assess if its occurrence, even in absence of a relevant motor impairment, can be reported by patients with descriptions which might be misleading for the treating physician (e.g. complaining of difficulty in manipulation). METHODS: subjects affected with stable CIPN were enrolled in the CI-PeriNomS study and were neurologically assessed with different outcome measure tools while at the same time they filled several Patient Reported Outcome Measures (PROs). For the purpose of the present analysis, neurological examination was scored using the clinical version of the Total Neuropathy Score (TNSc®) using the items addressing motor symptoms and impairment in vibration sensibility and strength. Appropriated questions were selected for comparison with PROs among the original data set of questions used to create the Rasch built specific questionnaire, with a focus on those referring to manipulation and gait unbalance/postural instability. Correlations among variables were obtained through Spearman correlation. RESULTS: one hundred eighty one patients were available for the analysis; 77% of them had no motor impairment both in hands and feet at the TNSc® strength assessment. Nevertheless, 52% of subjects reported difficulty in manipulating objects and 53% difficulty in controlling distal parts of lower limbs. Conversely, vibration threshold was impaired in 70% in lower limbs and in 47% in upper limbs. Significant correlation was found between vibration threshold impairment in upper limbs and level of discomfort reported when asking patients about object manipulation, in particular when asking on “buttoning a shirt” (p<0.001) and “zipping/unzipping trousers” (p<0.001). DISCUSSION and CONCLUSION: sensory ataxia is an important issue in CIPN population and it should be properly assessed and estimated, while frequently it can be misdiagnosed as motor impairment if a careful neurological examination is not performed. Vibration threshold might be a useful to suggest sensory ataxia presence due to reduced sensory perception. Recognition of sensory ataxia is a key issue since this condition can benefit from physical therapy.