The role of impulsivity in neurorehabilitation: A prospective cohort study of a potential cognitive biomarker for fall risk?

BACKGROUND: Executive dysregulation and impulsivity can both predispose individuals to risk-prone actions. Although the risk of falls is well established in people with poor executive function, its association to impulsivity is less clear. PURPOSE: To describe and assess the prognostic capabilities of the relationship between impulsivity, executive function, functional capability, and falls in the in-patient neurorehabilitation population. MATERIALS AND METHODS: A prospective cohort study in a 26-bed neurorehabilitation unit in London, recruiting 121 patients, of whom 94 were deemed eligible for inclusion. Cognitive-behavioural assessment was undertaken using the short (16-item) version of the Urgency-Premeditation-Perseverance-Sensation Seeking-Positive Urgency (UPPS) impulsive behaviour scale, and the Trail Making Test (TMT). Patients also underwent a functional assessment at admission and discharge using the UK Functional Independence and Assessment Measure tool (FIM + FAM). The main outcome of interest was falling during an in-patient episode, which are routinely recorded in a computerized registry of adverse incidents. RESULTS: Measurements of impulsivity (based on the UPPS-Short form) and executive function (based on the Trail Making Test) were not found to be significantly associated with functional improvement, or risk of falling. Predictive modelling experiments demonstrated that neither of the aforementioned results were capable of identifying individuals at risk of falling more accurately than an informed guess. CONCLUSION: Where impulsivity is present, measurement using structured tools such as the UPPS may be informative to guide individualized rehabilitation programmes; however, its usefulness as the basis of risk prediction models for falls is less likely given the results of this study.