The Alzheimer's Biomarker Consortium - Down Syndrome (ABC-DS) - Gait Supplement

ABCDS Gait Supplement Abstract: Alzheimer’s disease (AD) is the most common cause of dementia and with people living longer the prevalence of AD is rapidly increasing. This increased prevalence is especially seen in Down Syndrome (DS) populations with virtually all people with DS developing significant AD neuropathology. Additionally, this DS populations often develop AD-related neuropathology significantly sooner (around middle age) than in the general population. The Alzheimer Biomarker Consortium - Down Syndrome (ABC-DS) is a research consortium whose primary focus is to search for viable markers of early signs of AD. One noninvasive measure that has been shown to decline prior to the emergence of dementia symptoms and neuropathology (cerebral Aβ deposition) in non-DS populations is reduced gait speed. Additionally, our group at the University of Kentucky recently demonstrated a similar decline in gait speeds during a dual- task paradigm in a DS population. This study also revealed that individuals with a moderate intellectual disability were less affected by the dual-task paradigm, suggesting that more research is needed to further explore using gait performance as a means of monitoring AD progress in a DS population. Therefore, the purpose of the proposed supplemental award will be to 1) demonstrate the ability of multiple ABC-DS sites and different study teams to reliably conduct the study protocol and collect data using the GAITRiteTM system; 2) pilot novel tasks to discriminate between cognitively stable individuals and those with mild cognitive impairment/ AD in a DS population; 3) examine the association of gait measures with other biomarkers, allowing us to begin to see where gait sits within the cascade of DS biomarker changes that precede dementia; 4) gather pilot data for a power analysis to determine the appropriate sample size for a larger scale future award submission to longitudinally track changes in gait as a potential AD biomarker in DS.