Multisensory integration (MSI) is an integral aspect of functioning and mobility in everyday life and ability to function well in the real world requires intact MSI. MSI is not fully understood in aging, and its relation to cognitive and motor function has not been comprehensively evaluated. The main objective of my research is to investigate the behavioral, functional, and structural correlates of MSI in older adults and to determine whether multisensory processes are associated with specific cognitive and motor outcomes. Our recent work in older adults has linked the magnitude of visual-somatosensory integration to important cognitive (attention) and motor (balance, gait, and falls) outcomes. We have highlighted the adverse effect of Mild Cognitive Impairment (MCI) and dementia on these relationships, but the underlying functional and neuroanatomical networks remain unidentified.
Growing evidence suggests that Alzheimer’s pathology manifests in sensory association areas well before appearing in neural regions involved in memory function. Identification of novel, non-cognitive, non-invasive markers of Alzheimer’s disease and related dementias are a national priority identified by the National Alzheimer Plan and the NIH. Our most recent NIA funding affords us an opportunity to determine whether visual-somatosensory integration is a novel marker for Alzheimer’s disease. Our central hypothesis is that preclinical Alzheimer’s disease is associated with neural disruptions in subcortical and cortical areas that concurrently modulate multisensory, cognitive, and motor functions, resulting in mobility decline. Our proposed study, strategically designed to examine the interplay of multisensory, cognitive, and mobility processes, will: 1) provide a deeper understanding of the functional neural networks involved in MSI processes in preclinical Alzheimer’s disease; 2) determine whether functional multisensory activation in prefrontal cortex predicts future mobility decline and falls in preclinical Alzheimer’s disease; 3) assess the validity of multisensory integration as an early marker for preclinical Alzheimer’s disease; and 4) provide insights into the neurobiology of Alzheimer’s disease. Results from this project will guide future multisensory-based interventions aimed to alleviate disability and maintain functional independence of older adults at-risk for Alzheimer’s disease that can significantly augment existing interventions. Although admittedly speculative, we believe that optimizing integration of visual-somatosensory inputs may ultimately provide the framework for successful interventions that will reduce falls, improve mobility, and help maintain functional independence in older adults.
As well, we have made significant strides with regards to identifying a novel quantitative multisensory fall-risk screening tool called CatchU® Before you Fall... Falls are a significant burden to the U.S. healthcare system with over $50B spent annually on fatal and non-fatal falls. Nearly 30% of Americans aged 65 years and over (~16M) experience a fall every year. Falls are the leading cause of injury and injury-related death in older adults. Alzheimer’s disease, the most-common cause of dementia, affects nearly 6M older Americans. Besides cognitive impairment, older adults with Alzheimer’s disease are at high-risk for mobility declines and falls. The main objective of our novel multisensory fall-risk screener is to assist healthcare professionals in predicting and preventing falls in older adults with preclinical Alzheimer’s disease. Long-term goals include preventing serious injury and death in older adults, while offsetting the accelerating economic burden of falls in the United States.