Factors that contribute to balance and mobility impairments in individuals with Huntington's disease

AbstractMobility and balance problems are common and often debilitating features of Huntington's disease (HD). In this exploratory study we aimed to investigate the influence of disease severity, severity of motor deficits, lower limb muscle strength, cognition, executive function, lean muscle mass and reactivity on mobility and balance.Twenty-two individuals with HD were recruited from the North Metropolitan Area Mental Health Service, Perth, Australia. Pertinent demographic, genetic and disease progression information was recorded prior to testing. Balance was assessed using dynamic and static balance tasks. Mobility was assessed using self-paced and fast-paced mobility measures. Cognitive and executive measures were used to assess verbal learning and memory, information processing speed, attention, response inhibition and cognitive flexibility. Lower limb muscle strength was evaluated by maximal isokinetic and isometric voluntary contractions. Lean tissue mass was quantified using Dual-energy X-ray absorptiometry. Reactivity was measured using Moyart equipment.Univariate and multivariate linear regression statistical models were used to examine the influence of these measures on mobility and balance. Univariate analyses showed that disease severity as well as measures of information processing speed, attention, cognitive flexibility, response inhibition and lower limb strength, were strongly related with mobility and balance. Additionally multivariate analyses showed that disease severity, cognitive flexibility and knee flexion strength together were better able to explain mobility and balance performance than any single measure (50–85%).In conclusion, our preliminary results suggest that as well as disease severity, cognitive and executive impairment and reduced lower limb strength contribute significantly to mobility and balance problems