Clinical assessment of mobility and balance impairments in pre-symptomatic Huntington's disease

Background: Quantitative movement analysis can detect impairments in mobility and balance in persons with pre-symptomatic HD (pre-HD); however, it is not known whether clinical tests can also detect such impairments. Given the ease of administering clinical tests, and the importance of assessing mobility and balance, we examined whether clinical tests can detect motor impairments in individuals with pre-symptomatic HD. Methods: Two clinical tests (Functional Reach Test [FRT] and Timed Up and Go [TUG]) and the Unified Huntington's Disease Rating Scale (UHDRS) were administered, along with quantitative gait analysis, to 15 individuals with pre-symptomatic HD and 15 controls. Results: There was no difference in FRT and TUG scores across groups. Neither test was correlated with years to predicted disease onset or with quantitative gait analysis measures. Conclusion: Clinical assessments such as FRT and TUG are not sensitive in detecting motor impairments in individuals with pre-symptomatic HD. The subtle nature of impairments provides a rationale for the use of quantitative gait analysis in pre-symptomatic HD.