This study aims to evaluate the feasibility, acceptability, and preliminary effects of a home-based, remotely supervised intervention combining transcranial direct current stimulation (tDCS) and online chair yoga (OCY) to manage chronic knee pain in older adults with Alzheimer's Disease and Related Dementias (ADRD). Chronic knee pain is prevalent among individuals with ADRD and is often underdiagnosed and undertreated, contributing to neuropsychiatric symptoms, reduced quality of life, and increased caregiver burden. Current pharmacological options, such as opioids, pose risks of adverse events in this population. tDCS is a safe, noninvasive technique that uses low-intensity electrical current to modulate brain activity and may improve pain perception by targeting central mechanisms. Chair yoga is a mind-body intervention shown to improve pain and mood in older adults, including those with dementia. This study proposes that combining tDCS and OCY may have synergistic benefits in reducing pain and enhancing function. Participants will include older adults aged 60+ with mild to moderate ADRD and chronic knee pain, along with their caregivers. Over four weeks, participants will complete 14 supervised sessions of combined tDCS and OCY at home. Outcomes include feasibility, satisfaction, pain intensity, pain interference, neuropsychiatric symptoms, sleep disturbance, cognitive function, mobility, and quality of life. Neurophysiological measures (e.g., fNIRS, EEG, HF-HRV) will also be assessed to explore underlying mechanisms. This study seeks to lay the foundation for future large-scale randomized controlled trials of home-based nonpharmacological interventions for chronic pain in ADRD.
Older adults with ADRD frequently experience chronic pain, particularly knee pain, which is associated with worse behavioral symptoms and faster cognitive decline. Despite its impact, pain is often inadequately treated in this population due to communication difficulties and the risks associated with pharmacological treatments, especially opioids. Transcranial direct current stimulation (tDCS) is a promising nonpharmacological therapy that delivers low-intensity electrical current to modulate cortical excitability. Research suggests that tDCS can reduce clinical and experimental pain and improve pain processing, particularly when targeted to the motor cortex. Our group has demonstrated the safety and efficacy of home-based, remotely supervised tDCS in older adults, including those with ADRD. Chair yoga (CY), a modified yoga intervention involving seated or chair-supported postures, is also safe and effective for older adults with chronic pain and cognitive impairment. CY has demonstrated benefits in reducing pain, improving mood, and promoting physical activity with minimal risk of falls. Evidence suggests that yoga interventions may enhance central pain modulation and reduce neuropsychiatric symptoms. This pilot study tests a novel combination of tDCS and online CY (OCY) in a home-based setting. We hypothesize that combining tDCS and OCY will reduce chronic knee pain and improve related symptoms in older adults with ADRD. Participants will be recruited from geriatric outpatient clinics and community settings. Eligible participants will be 60 years or older, have mild to moderate ADRD, and experience chronic knee pain. The intervention will include 14 sessions over four weeks. All sessions will be supervised remotely via a secure videoconferencing platform. Primary outcomes are feasibility, acceptability, and satisfaction, assessed through recruitment, adherence, dropout rates, and participant feedback. Secondary outcomes include reductions in knee pain (measured by Numerical Rating Scale and MOBID-2), pain interference (PROMIS Pain Interference 4a), sleep disturbance (ActiGraph), neuropsychiatric symptoms (Neuropsychiatric Inventory Questionnaire), cognitive function (Montreal Cognitive Assessment and Cognivue), mobility (Timed Up and Go), and quality of life (QOL-AD). Exploratory neurophysiological outcomes will include functional near-infrared spectroscopy (fNIRS) to assess pain-related brain activity, EEG for neural pain signatures, and high-frequency heart rate variability (HF-HRV) for autonomic function. This study will help determine the feasibility and potential effects of a scalable, home-based tDCS+OCY protocol, with the goal of informing future large-scale trials and advancing personalized, nonpharmacological pain care in ADRD.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
40
Active tDCS with a constant current of 2 milli amperes (mA) will be applied for 20 minutes daily for 1 week, and 20 minutes 3 times per week for 3 weeks via the Soterix 1x1 tDCS mini-CT Stimulator device with headgear and saline-soaked surface sponge electrodes. Online chair yoga therapy lasting 30 minutes will be conducted via Zoom by a yoga therapist immediately after each tDCS session.
University of Arizona College of Nursing
Tucson, Arizona, United States
RECRUITINGNumeric Rating Score (NRS) of Pain
Clinical pain intensity will be measured by asking participants to rate their knee pain over the last 24 hours between 0 (no pain) - 10 (worst pain imaginable). The NRS has a reported Cronbach's alpha coefficient of ≥ 0.8 and is a reliable way for measuring knee pain in adults with knee osteoarthritis.
Time frame: Baseline (Week 0); after each intervention session (Sessions 1-14 over Weeks 1-4); and end of intervention (Week 4).
Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference 4a
The PROMIS Pain Interference 4a measures pain's impact on daily activities, with four items rated on a 5-point scale. Patients will self report this data based on their activities from the last 7 days. This tool has high reliability with a Cronbach's alpha \~0.90.
Time frame: Baseline (Week 0); after each intervention session (Sessions 1-14 over Weeks 1-4); and end of intervention (Week 4).
Mobilization-Observation-Behavior-Intensity-Dementia Pain Scale (MOBID-2)
The MOBID-2 asks caregivers to evaluates the pain of participants during specific activities(guiding hands together, turning in bed, sitting at bedside, etc.) and at specific parts of the body (head, mouth, neck, heat lungs, chest wall, etc), with a score range of 0-10; scores over 2 are clinically significant. The MOBID-2 shows high reliability with a Cronbach's alpha 0.86-0.89.
Time frame: Baseline (Week 0); after each intervention session (Sessions 1-14 over Weeks 1-4); and end of intervention (Week 4).
ActiGraph Watch
The ActiGraph wGT3X-BT and ActiLife software objectively measures sleep disturbance. Wrist actigraphy is a valid and reliable tool for assessing sleep in patients with ADRD. Patients will be asked to wear the watch on their nondominant wrist, with caregiver assistance. Actigraphy data are analyzed to calculate sleep outcomes, including total sleep time, wake time, and daytime naps, using the standard algorithm in ActiLife software without additional hand scoring.
Time frame: Continuously assessed from baseline (Week 0) through end of intervention (Week 4).
The Montreal Cognitive Assessment (MoCA v. 8.1)
MoCA is a 30-point test that includes 12 subtasks that cover a total of 8 cognitive domains (e.g., memory, orientation, attention/concentration, executive function), with scores ranging 0-30, with higher scores indicating better global cognitive performance. The MoCA features educational correction by the addition of 1 point for the patient with less than a 12th-grade education. The MoCA has high internal reliability (Cronbach α = .83), high test-retest reliability (ICC = 0.92), high interrater reliability (ICC = .81), and high content validity (r = .87).
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Functional near-infrared spectroscopy (fNIRS) brain imaging
Pain related cortical responses will be measuring using a continuous multichannel fNIRS imaging system (LIGHTNIRS, Shimadzu, Kyoto, Japan). This instrument encompasses 8 light sources (each emitting laser light at 780, 805, and 830 nm) and 8 detectors connected to comfortable headgear using optical fibers. Optical recordings will be collected during thermal pain stimulation and punctate pain stimulation.
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Heart Rate Variability Monitor
The Bittium Faros™ 180 device will be used to record continuous electrocardiogram (ECG) data for analyses of cardiac rhythms. The device samples ECG at 1000 Hz and is attached using three self-adhesive electrodes on the torso. Respiratory Sinus Arrhythmia (RSF) and Heart Rate (HR) will be measuring over 3 minutes during 3 postures (stand-sit-stand) for a total collection period of 9 minutes.
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Neuropsychiatric Inventory Questionnaire (NPI-Q)
The NPI will be administered to the caregiver to evaluate the participant's neuropsychiatric symptomatology of dementia. The NPI uses a 4-point Likert-type scale for frequency and a 3-point Likert-type scale for severity of 12 sub-domains of dementia (e.g., delusions, hallucinations, agitation/aggression, night-time behavioral disturbances, and appetite and eating abnormalities). These are summed to yield an overall score of 0-144 (each item rated frequency X severity, totaling 0-12), with higher scores indicating greater symptoms. Internal consistency reliability of the NPI is high with a Cronbach's alpha = 0.80.
Time frame: Baseline (Week 0); during intervention on Days 5, 8, 11, and 14 (Weeks 1-4); and end of intervention (Week 4).
Time Up and Go Test (TUG)
TUG will measure functional mobility by timing patients as they stand from a chair, walk 10 feet, turn 180 degrees, return, and sit down. The average of three tests will be recorded in seconds. TUG is a simple and widely used tool for assessing lower limb function, mobility, and fall risk, with high inter-rater (ICC = .99) and intra-rater reliability (ICC = .99).
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Cognivue Clarity
Cognivue Clarity is the first FDA-cleared computerized cognitive assessment device to evaluate a range of specific cognitive domains (e.g., motor speed, visuospatial abilities, verbal and visual episodic memory, attention, executive function, reaction time). It is an easy-to-use automated platform for evaluating and tracking cognitive impairment, with 10 separately scored subtests (2 for visuospatial functioning, 4 for perceptual processing, and 4 for memory). The 10-minute assessment provides a numerical score categorizing performance as normal, mild impairment, or moderate impairment. Classification ranges are no cognitive impairment (CI) (≥75), low-mild CI (51-74), and moderate-severe CI (≤50).
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Client Satisfaction Questionnaire (CSQ-8)
We will measure participant satisfaction with treatment using the CSQ-8. The CSQ-8 comprises eight items that are summed to yield an overall score of 8-32, with higher scores indicating greater satisfaction. The CSQ-8 has a reported Cronbach's alpha coefficient of 0.87-0.93. We will evaluate the presence and severity of possible side effects of treatment at the end of each session on a 0 (not at all) to 10 (highest degree) scale. Participants will be asked in an open-ended manner whether they experienced any side effects, and they will complete a brief questionnaire assessing side effects that can occur with tDCS or/and OCY (e.g., itching, headache, fatigue, dizziness).
Time frame: End of intervention (Week 4).
Acceptability and Experience Survey
To measure acceptability, we will administer an adapted questionnaire to patients and caregivers at the end of the intervention. Items rated from 0 (strongly disagree) to 10 (strongly agree) will include (a) ease of preparing tDCS and chair yoga props, (b) complexity and usability of the tDCS device, (c) ease of following yoga poses, (d) helpfulness of video conferences, (e) confidence in using tDCS, and (f) overall benefit of the interventions. Negative items will be reverse coded, and total scores will range from 0 to 100, with higher scores indicating greater acceptability.
Time frame: End of intervention (Week 4).
Quick Dementia Rating Scale (QDRS)
The QDRS is a brief, informant-based tool designed to assess cognitive function and detect dementia quickly, typically in 3-5 minutes. It evaluates 10 domains, including memory, orientation, decision-making, and daily activities, with scores ranging from 0 to 30, where higher scores indicate greater impairment. * 0-1.5: No dementia * 2.0-5.5: Mild cognitive impairment (MCI) * 6.0-12.5: Mild dementia * 13.0-20.5: Moderate dementia * 21-30: Severe dementia
Time frame: Baseline (Week 0)
Conditioned Pain Modulation (CPM)
Descending pain modulation will be assessed by measuring the change in pressure pain threshold on the trapezius immediately after immersing the contralateral hand up to the wrist in a 12 °C cold-water bath for one minute. An increase in pressure pain threshold following immersion indicates stronger descending pain modulation, with higher CPM scores reflecting better modulation.
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Quality of Life Alzheimer's Disease Questionnaire (QOL-AD)
Quality of Life will be assessed using the 13-item QOL-AD, which evaluates physical health, mood, memory, and overall life satisfaction. Each item is rated from 1 (poor) to 4 (excellent), with total scores ranging from 13 to 52; higher scores indicate better QOL. The QOL-AD has high Internal consistency (Cronbach α = 0.80 to 0.89) and strong validity, correlating well with other QOL measures, cognitive function, and mood assessments.
Time frame: Baseline (Week 0) and end of intervention (Week 4).
Mini-Montreal Cognitive Assessment (Mini-MoCA)
Mini-MoCA: The 5-minute Mini-MoCA is a shortened version of the MoCA, targeting tasks most sensitive to mild cognitive impairment. It takes approximately 5 minutes to administer and assesses five cognitive domains: attention, verbal learning and memory, executive function/language, and orientation. The cut-off score is 12, with 1 point added for persons with less than 12 years of education.
Time frame: Pre-baseline screening assessment (prior to Week 0).
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.