How different aspects of motor dysfunction influence day-to-day function in huntington's disease

Abstract

Purpose: This study examined the relationships between different aspects of motor dysfunction (chorea, dystonia, rigidity, incoordination, oculomotor dysfunction, dysarthria, and gait difficulties) and functional status in persons with Huntington's disease. Methods: A total of 527 persons with Huntington's disease completed the Unified Huntington's Disease Rating Scale motor, total functional capacity, and functional assessments. Results: Confirmatory factor analysis indicated that a 4-factor model provided a better model fit than the existing 5-factor model. Exploratory factor analysis identified the following 4 factors from the motor scale: dystonia, chorea, rigidity, and a general motor factor. Regression indicated that dystonia (β = −0.47 and −0.79) and rigidity (β = −0.28 and −0.59) had strong associations with function, whereas chorea had modest correlations (β = −0.16 and −0.15). Conclusions: Dystonia and rigidity have stronger relationships with functional status than chorea in persons with Huntington's disease. The findings underscore the need for further research regarding the effects of dystonia and rigidity on functioning. © 2019 International Parkinson and Movement Disorder Society.