F034 The flamingo study: single leg stance time provides unique insight to motor progression in Huntington’s disease

<h3>Background</h3> Single Leg Stance Time (SLST) is a quick and straightforward method of examining balance. It has been used to assess balance in older adults and can be followed over time. <h3>Methods</h3> This retrospective study assessed how SLST correlates with other measures of balance and function in Huntington’s disease (HD). We reviewed charts of 77 individuals with a genetic diagnosis of HD seen between 1/1/15 – 6/31/22, aged 18–90 years, who had undergone formal assessments including SLST. <h3>Other measures included</h3> UHDRS-Total Motor Score (TMS), Total Functional Capacity (TFC), gait speed, Tinetti Mobily Test (TMT) and Functional Gait Assessment (FGA). Mixed-effects multivariable regression models controlling for age, sex, and years from onset were used to determine relationships between SLST and other measures. <h3>Results</h3> A decrease in SLST of 3 seconds was significantly associated with worsening of TMS and TFC scores demonstrating that SLST is related to disease progression. Scores on FGA, TMT and decreases in gait speed were also associated with disease progression. There was no linear association between TMS chorea or mobility sub-scores and SLST, TMT, gait speed or TFC. However, the correlation between chorea scores and SLST approached significance (p=.077). <h3>Conclusions</h3> SLST had excellent correlation with FGA and TMS and moderate correlation with TMT and TFC. SLST and FGA appeared better at capturing early motor and balance changes while TMT appeared better at capturing and assessing mobility function in later stages. Interestingly, chorea is likely not a primary contributor to changes in mobility and motor function in individuals with HD.