2026 Theses Doctoral

Sensory Integration and Cognitive Motor Interference in Older Adults with Mild Cognitive Impairment

Smith, Genevieve B.

Background:
Mild cognitive impairment (MCI) is a clinical syndrome characterized by objective impairment in cognitive function, but preserved independence of daily activities (Petersen, 2004). Approximately 50% of those with MCI may later develop dementia (Gauthier et al., 2006; Petersen et al., 2018). Recent evidence suggests that balance and gait impairments are frequently observed in older adults with MCI and incorporating these measures into clinical assessments may enhance diagnosis accuracy of MCI (Bahureksa et al., 2016). Older adults with MCI demonstrate an increased prevalence of falls compared to cognitively healthy older adults, secondary to several factors including impaired postural control and cognitive motor interference.

This dissertation highlights two domains of postural control proposed by Horak (2006): sensory strategies and cognitive strategies (i.e., attention) and has two objectives. The pilot study addressed the first objective: to examine if older adults with MCI demonstrate impaired sensory integration strategies compared to older adults without MCI. While there is some evidence suggesting older adults with MCI demonstrate impaired sensory strategies of postural control compared to older adults without MCI during static balance conditions with all sensory information available, less is known during static balance conditions with limited/unreliable visual and somatosensory input. The dissertation study addressed the second objective: to examine whether older adults with MCI demonstrate cognitive motor interference compared to older adults without MCI. While some work has examined cognitive motor interference during static balance conditions in older adults with MCI with all sensory information available, less is known about cognitive motor interference during static balance conditions with limited/unreliable somatosensory and visual input.

Results:
In the pilot study, older adults with MCI performed the modified Clinical Test of Sensory Integration and Balance (mCTSIB) with wearable sensors (APDM) and other physical assessments, and results were compared with normative data of healthy controls published by APDM. Findings from this study suggest older adults with MCI demonstrated greater magnitude of sway area and jerk, indicating impaired sensory integration strategies. In the dissertation study, older adults with and without MCI performed the mCTSIB with and without a simultaneous cognitive task (serial subtraction by 3’s) and other physical assessments. Findings from this study suggest (1) older adults with MCI demonstrate cognitive motor interference compared to older adults without MCI, and (2) older adults with MCI demonstrate prioritization of cognitive task during static standing balance conditions with increased postural task complexity.

Conclusion:
The findings from this dissertation suggest older adults with MCI demonstrate impaired sensory integration strategies and cognitive motor interference compared to older adults without MCI. Results also suggest older adults with MCI demonstrate altered task prioritization compared to cognitive healthy older adults. This has important clinical implications. Future work should explore different components of task prioritization to develop the most effective dual task paradigms for fall prevention programs in older adults with MCI. Future work should also examine whether assessing sensory integration, cognitive motor interference, and task prioritization during static balance conditions can enhance accuracy of diagnosing MCI and predict progression from MCI to dementia.