Cognitive-Motor Training for AD/ADRD Prevention

Alzheimer's disease/Alzheimer's disease and related dementias (AD/ADRD) significantly impair cognitive function and the ability to perform activities of daily living in older adults. Mild Cognitive Impairment (MCI) is a transitional phase between age-associated cognitive decline and dementia, which affects about 17% of older adults and can impair multiple domains of cognitive functioning (executive function, memory, etc.). Further, there is a well-established relationship between cognitive decline and reduced mobility, and OAwMCI show gait and balance deficits compared to cognitively intact older adults (CIOA), resulting in a 2-fold increase in the risk of falling. Fall-related consequences (e.g., injury) can significantly increase sedentary behavior and reduce physical activity, thus leading to a vicious cycle of deconditioning and reduced mobility, which significantly increases the risk of experiencing another fall. Further, sedentary behavior and deconditioning can accelerate the rate of conversion from MCI to AD/ADRD.

Exercise interventions are a promising approach to not only improve motor function, balance, and mobility in OAwMCI but also to improve cognitive function via several mechanisms of action. However, few exercise interventions for OAwMCI explicitly target cognitive processing in challenging conditions, such as dual tasking (i.e., simultaneous motor+cognitive task). Exergaming is a form of dual-task training that could reduce CMI in OAwMCI by providing combined cognitive stimulation and motor training in challenging environments that activate multiple cognitive processes, using digital gaming platforms. However, most existing exergames have focused only on the physical domain (promoting physical activity or exercise), and there is limited evidence on whether exergaming yields more cognitive benefit than conventional training. To explicitly target cognitive function and dual tasking ability, the investigators have developed a novel paradigm that integrates advanced computer vision technology and a cloud-based platform to provide more scalable, engaging, and customizable cognitive-motor training for OAwMCI. This CXT paradigm overcomes barriers of commercial exergaming systems (Wii Fit, Kinect) and requires minimal technology (webcam, computer/tablet), thus being more scalable and cost-effective.

The current proposal will examine the effects of 8 weeks of CXT on dual tasking ability, balance, and mobility, and patient-centered outcomes in OAwMCI, compared to an exercise and education program (EEP).

Aim 1: Examine the immediate effects of CXT on mechanistic measures of CMI in OAwMCI by comparing the dual task costs during both volitional and reactive balance tasks between groups after 8 weeks of training.

Aim 2: Examine the immediate effects of CXT on dynamic balance, mobility, and endurance in OAwMCI, and the investigators will also compare the cognitive function using the NIH cognitive toolbox between groups immediately after the training (Ancillary Aim).

Aim 3: Examine the immediate and sustained effects of CXT on patient-centered measures of physical activity, falls efficacy, and quality of life, and examine whether reductions in CMI (Aim 1) and improved balance, mobility, and endurance (Aim 2) will mediate improvements in patient-centered outcomes.

Exploratory analysis: To understand stakeholder (participants, clinicians) perceptions regarding CXT and facilitators/barriers for translation of the intervention into home and community settings, focus groups will be conducted to assess system usability, acceptability, attitudes, and intrinsic motivation via self-reported questionnaires and recorded transcripts.

Inclusion criteria

• Age: 55-90 years.
• No recent major surgery, bone fracture, or hospitalization (< 3 months).
• Not on any sedative drugs.
• Can understand and communicate in English.
• Can walk without an assistive device for at least 1 block to ensure independent functioning.
• Identification of Mild Cognitive Impairment (MCI) based on Jak/Bondi criteria
• Visual acuity greater than or equal to 20/40 with or without corrective lenses to ensure intact vision.

Exclusion criteria

• Participants will not proceed with the study if any of the following occurs at baseline measurement: 1) Heart Rate >85% of age-predicted maximal heart rate (HRmax) (HRmax = 220 - age), 2) systolic blood pressure (SBP) > 160 mmHg and/or diastolic blood pressure (DBP) > 110 mmHg during resting.
• Unable to stand for 5 minutes without an assistive device and walk for 10 m without an assistive device
• Complaints of shortness of breath, or uncontrolled pain (more than 3 out of 10 on Visual Analogue Scale), or if pulse oxygen drops less than 92% on the six-minute walk test (for endurance) to ensure that the participant can effectively participate without discomfort or injury during testing and training.
• Exhibits difficulty understanding the study information.
• Self-reported history or presence of any neurological, musculoskeletal, cardiorespiratory, or systemic disorders that significantly impact mobility or the ability to walk independently (without an assistive device).
• Self-reported disability (with or without an assistive device) to ensure independent functioning.
• Uncontrolled (not under any medications) hypertension to avoid cardiovascular complications during testing/training.
• Weight >220 lbs (harness weight threshold).