Gait is associated with age and dementia assessments among individuals with Down syndrome

Abstract

AbstractBackgroundDown Syndrome (DS), caused by triplication of chromosome 21, is associated with the development of Alzheimer's disease (AD) neuropathology by age 40 years. However, clinical signs of dementia may not develop until up to decades after neuropathology. Neuroimaging studies indicate that the striatum and frontal lobes accumulate beta‐amyloid early in AD progression. Given these regions are involved in motor and cognitive function, we hypothesized that gait would be associated with changes in cognition and prodromal dementia.MethodTwenty‐nine participants (n = 16 male) with DS were recruited into the gait study. The average age of participants was 36 (range: 25‐59). The GaitRite mat was used to spatial and temporal gait measures while participants walked at their self‐selected pace or when completing a dual‐task. The dual‐task was counting aloud, starting from a random integer between 1‐10. Participants also completed the Severe Impairment Battery (SIB) and Brief Praxis Test (BPT) to measure cognitive impairment. Linear mixed models evaluated the relationship between age, condition, and gait metrics. Linear regression was used to assess the relationship between gait and cognition metrics.ResultWith increasing age, gait velocity slowed within the counting condition, but not the self‐paced condition (t(180.29) = 2.69; p = 0.008; Figure 1A). There was a trend for step length to shorten with increasing age across all conditions (t(29.01) = ‐1.81; p = 0.08; Figure 1B). Participants’ base stance was wider with increasing age during the counting condition, but not the self‐paced condition (t(179.70) = ‐2.03; p = 0.04; Figure 1C). Faster normalized velocity was associated with better cognition as measured by the SIB (t = 2.99; p = 0.004; Figure 2A) and BPT (t = 2.02; p < 0.05; Figure 2B) across both self‐paced and counting conditions.ConclusionSlower velocity, shorter step length, and wider base stance on the dual‐task gait paradigm were associated with increasing age and cognitive impairment. A dual‐task gait may serve as a prodromal indicator of dementia in DS. Earlier dementia detection will facilitate research investigating ADS pathogenesis and subsequently may provide novel targets for preventative research.