Music Listening for Chronic Pain in Adults With Early-Stage Dementia

Participants assigned to this sequence will begin with a MUSIC CARE® session before proceeding through the remaining randomized listening conditions. Each participant will complete eight 30-minute sessions, consisting of two morning MUSIC CARE® sessions, two afternoon MUSIC CARE® sessions, two morning audiobook control sessions, and two afternoon audiobook control sessions. The order of subsequent conditions will follow the study's counterbalanced randomization schedule.

MUSIC CARE® is a standardized digital music listening intervention that uses a U-sequence algorithm to structure instrumental music within the participant's preferred genre. Participants will listen for 30 minutes using study-provided headphones in their homes, with caregiver assistance and remote research staff supervision. Each participant will complete four MUSIC CARE® sessions, including two morning sessions between 9:00 AM and 11:00 AM and two afternoon sessions between 3:00 PM and 5:00 PM. The intervention will be delivered as part of a randomized, counterbalanced, within-subject crossover protocol.

The control intervention consists of neutral educational or documentary spoken-word audiobook passages without musical accompaniment, matched to MUSIC CARE® for listening duration and delivery format. Participants will listen for 30 minutes using study-provided headphones in their homes, with caregiver assistance and remote research staff supervision. Each participant will complete four audiobook control sessions, including two morning sessions between 9:00 AM and 11:00 AM and two afternoon sessions between 3:00 PM and 5:00 PM.

Participants assigned to this sequence will begin with a neutral spoken-word audiobook session before proceeding through the remaining randomized listening conditions. Each participant will complete eight 30-minute sessions, consisting of two morning MUSIC CARE® sessions, two afternoon MUSIC CARE® sessions, two morning audiobook control sessions, and two afternoon audiobook control sessions. The order of subsequent conditions will follow the study's counterbalanced randomization schedule.

MUSIC CARE® is a standardized digital music listening intervention that uses a U-sequence algorithm to structure instrumental music within the participant's preferred genre. Participants will listen for 30 minutes using study-provided headphones in their homes, with caregiver assistance and remote research staff supervision. Each participant will complete four MUSIC CARE® sessions, including two morning sessions between 9:00 AM and 11:00 AM and two afternoon sessions between 3:00 PM and 5:00 PM. The intervention will be delivered as part of a randomized, counterbalanced, within-subject crossover protocol.

The control intervention consists of neutral educational or documentary spoken-word audiobook passages without musical accompaniment, matched to MUSIC CARE® for listening duration and delivery format. Participants will listen for 30 minutes using study-provided headphones in their homes, with caregiver assistance and remote research staff supervision. Each participant will complete four audiobook control sessions, including two morning sessions between 9:00 AM and 11:00 AM and two afternoon sessions between 3:00 PM and 5:00 PM.

Recruitment feasibility will be assessed by the number of eligible participant and caregiver dyads enrolled relative to the target sample of 20 dyads. Each dyad consists of one adult with early-stage Alzheimer's disease and related dementias (ADRD) and chronic pain and one eligible adult caregiver. Recruitment will be summarized as the number of enrolled dyads and the percentage of target enrollment achieved, calculated as the number of enrolled dyads divided by 20, multiplied by 100.

Retention will be assessed as the percentage of enrolled participant and caregiver dyads completing planned study procedures, including the intervention period and end-of-study assessments. The retention percentage will be calculated as the number of enrolled dyads completing study procedures divided by the total number of enrolled dyads, multiplied by 100.

Intervention adherence will be measured as the percentage of scheduled home listening sessions completed by each adult participant with ADRD. Each participant is scheduled to complete eight 30-minute sessions, consisting of two morning MUSIC CARE® sessions, two afternoon MUSIC CARE® sessions, two morning audiobook control sessions, and two afternoon audiobook control sessions. Adherence will be calculated as the number of completed sessions divided by eight, multiplied by 100.

Acceptability of the home-based listening intervention and caregiver-assisted study procedures will be evaluated using study-specific information collected from participants with ADRD and their caregivers. The assessment will address experiences with listening sessions, caregiver assistance, equipment setup, remote supervision, and physiological monitoring. Available responses will be summarized descriptively to characterize the acceptability of completing these procedures in the home setting.

EEG acquisition feasibility will be measured as the percentage of recorded EEG epochs retained as artifact-free and suitable for analysis after signal preprocessing and quality assessment. For each session, the percentage of artifact-free EEG epochs will be calculated as the number of usable epochs divided by the total number of recorded epochs, multiplied by 100. EEG will be acquired during five-minute eyes-closed resting periods before and after listening and continuously during the 30-minute listening intervention. At least 50% artifact-free epochs per session is the prespecified feasibility benchmark.

HRV data acquisition feasibility will be assessed by the completeness and analyzability of heart rate and RR interval recordings obtained using the Polar H10 sensor during home study sessions. Recordings will be evaluated for signal quality and suitability for deriving HRV indices following artifact screening. Data availability and analyzability will be summarized descriptively across scheduled resting and listening recording periods. No numerical HRV feasibility threshold is prespecified.

Pain intensity will be assessed using the participant-reported Numeric Rating Scale (NRS) immediately before and after each 30-minute listening session. Within-session change in pain intensity will be calculated as the post-session pain rating minus the pre-session pain rating, with negative values indicating reduced pain intensity. Changes will be examined across MUSIC CARE® and audiobook control conditions and morning versus afternoon delivery. Ratings will be obtained directly from participants with ADRD, without substituting caregiver proxy ratings.

Pain interference will be assessed using the Brief Pain Inventory Interference subscale (BPI-I) at baseline and study completion. The instrument evaluates the extent to which pain interferes with general activity, mood, walking ability, normal work, relationships with others, sleep, and enjoyment of life. Change in pain interference will be calculated as the study completion score minus the baseline score, with negative values indicating reduced pain-related interference.

Frontal alpha asymmetry (FAA) will be derived from electroencephalography (EEG) recorded with the X-trodes Smart Skin System M using the XTR EEG12 dry-electrode patch. After artifact removal, FAA will be calculated as ln(AF8 alpha power) minus ln(AF7 alpha power), using each participant's individual alpha frequency band. Higher values indicate relatively greater left than right frontal activity. For each session, the change in FAA from pre-session rest to the listening period, and from pre-session rest to post-session rest, will be calculated. Within-participant differences in these changes will be examined by listening type (MUSIC CARE® versus audiobook control), time of day (morning versus afternoon), and their interaction. Associations with participant-reported pain intensity, measured using the Numeric Rating Scale (NRS) before and after each session, will be explored.

Frontal theta power will be derived from EEG recorded with the X-trodes Smart Skin System M using the XTR EEG12 dry-electrode patch. After removal of blink, eye-movement, and muscle artifacts, theta power at AF7 and AF8 will be averaged and expressed as the natural logarithm of absolute power in each participant's individual theta frequency band (unit: ln µV²). For each session, the change in frontal theta power from pre-session rest to the listening period, and from pre-session rest to post-session rest, will be calculated. Within-participant differences in these changes will be examined by listening type (MUSIC CARE® versus audiobook control), time of day (morning versus afternoon), and their interaction. Associations with participant-reported pain intensity, measured using the Numeric Rating Scale (NRS) before and after each session, will be explored.

High-frequency heart rate variability (HF-HRV) will be derived from RR intervals recorded with a Polar H10 chest-strap sensor. After artifact correction, HF-HRV will be calculated as the natural logarithm of spectral power in the 0.15-0.40 Hz band (unit: ln ms²), computed in five-minute windows. The listening-period value will be the mean of its six five-minute windows. Windows with more than 5% corrected beats will be excluded. For each session, the change in HF-HRV from pre-session rest to the listening period, and from pre-session rest to post-session rest, will be calculated. Within-participant differences in these changes will be examined by listening type (MUSIC CARE® versus audiobook control), time of day (morning versus afternoon), and their interaction. Associations with participant-reported pain intensity, measured using the Numeric Rating Scale (NRS) before and after each session, will be explored.