Combined Exercise and PMS: Impact on Biopsychosocial Function in Older Adults With Schizophrenia

Project Experimental Protocol (Revised Version) This project consists of two randomized parallel-group experiments involving older adults with schizophrenia, aiming to evaluate the therapeutic effects of Peripheral Magnetic Stimulation (PMS) and its potential to enhance exercise-related benefits. The rationale for this project is based on evidence that peripheral neuromuscular stimulation can modulate sensorimotor integration and functional mobility, while being well-tolerated in older populations.

Experiment 1 (Efficacy of PMS) Participants are randomly assigned to either the active PMS group or the sham PMS group, with interventions administered over several weeks in addition to standard care. Both participants and outcome assessors are blinded, and device operators are kept separate from assessors. PMS parameters, treatment protocols, and device details are specified in the "Interventions" section.

Outcome measures are collected at baseline and post-intervention (with short-term follow-up when feasible) using validated clinical scales, functional assessment tools, and patient-reported instruments. Additionally, electroencephalographic (EEG) signals are recorded to generate spectrograms, brain topographic maps, and brain functional connectivity maps. Specific analyses include: ① Observing changes in EEG energy across different frequency bands (e.g., alpha, beta, theta waves) via spectrograms to determine PMS-induced regulatory effects on brain electrical activity rhythms; ② Identifying regions of abnormal EEG activity using brain topographic maps to pinpoint core brain functional areas (e.g., sensorimotor cortex, prefrontal lobe) potentially affected by PMS; ③ Analyzing alterations in connectivity strength between brain regions (e.g., frontal-parietal, intrahemispheric) through functional connectivity maps to explore PMS-mediated modulation of neural circuit connectivity, thereby providing neurophysiological evidence for the mechanisms underlying PMS efficacy. Safety is monitored during each session in accordance with predefined termination criteria.

Experiment 2 (Enhancement of Exercise Benefits) This independent randomized trial randomly assigns participants to three groups: exercise combined with PMS group, PMS alone group, and exercise alone group, with each group receiving interventions for several weeks. The exercise combined with PMS group and the exercise alone group follow the same standardized, dose-matched exercise protocol, while the exercise combined with PMS group and the PMS alone group use consistent PMS intervention parameters. Outcome assessors are blinded, and therapists responsible for exercise instruction strictly adhere to uniform operational protocols across all three groups.

The core objective is to compare the efficacy differences among the three interventions, with key assessment indicators including: ① **Palm-held ultrasound measurement: Targeting key lower limb muscles (e.g., quadriceps femoris, gastrocnemius muscle), palm-held ultrasound is used to detect muscle thickness and echo intensity to evaluate intervention-induced improvements in muscle structure and quality; ② 6-minute walk test: Measuring the maximum distance walked by participants in 6 minutes to assess aerobic endurance and exercise endurance; ③ Sit-to-stand test: Recording the time/number of repetitions for participants to stand up from a seated position and sit back down to evaluate lower limb muscle strength, balance ability, and functional mobility; ④ Positive and Negative Syndrome Scale (PANSS) scores: Quantifying improvements in participants' psychiatric symptoms across three dimensions (positive symptoms, negative symptoms, general psychopathology). Other assessment domains (e.g., cognition, sleep, health-related quality of life) are consistent with those in Experiment 1. Participant adherence to interventions is enhanced through structured appointment reminders, intervention logs, and regular follow-ups.

Common Methods for Both Experiments

• Randomization and Group Allocation**: Random sequences are computer-generated with concealed allocation. Stratification factors such as age, disease duration, and baseline motor ability may be incorporated as needed to reduce inter-group confounding.
• Statistical Analysis： Analyses follow the intention-to-treat principle, using mixed-effects models to estimate group-by-time interaction effects and evaluate time-dependent impacts of interventions on outcomes. If model assumptions (e.g., normality, homoscedasticity) are violated, nonparametric tests (e.g., Wilcoxon rank-sum test) are used as alternatives. Multiple testing errors for confirmatory endpoints (e.g., PANSS scores, 6-minute walk distance, palm-held ultrasound-derived muscle thickness indicators) are controlled using the Holm-Bonferroni method, while the false discovery rate (FDR) method is applied to exploratory endpoints (e.g., EEG-derived metrics).
• Data Processing: Missing data are handled using multiple imputation (generating 5-10 complete datasets), with sensitivity analyses of per-protocol populations to verify result stability. Data quality is ensured through assessor training (including PANSS rater consistency testing, standardized training for EEG data processing, and training on consistent operation of palm-held ultrasound), development of standard operating procedures (SOPs), and implementation of data range audits (e.g., excluding outliers beyond reasonable physiological ranges).
• Ethical and Safety Oversight: The Institutional Review Board (IRB) provides full supervision, and intervention protocols require ethical approval before implementation. Adverse events (e.g., local skin irritation, dizziness) are recorded during each visit, classified by severity, and regularly submitted to the IRB for review.

To avoid redundancy, specific timelines for outcome measurement (e.g., EEG recording schedules, PANSS assessment frequency, palm-held ultrasound testing times), inclusion/exclusion criteria, sample size calculations, detailed study procedures, and PMS device parameters are described in their dedicated Patient-Reported Outcomes (PRO) fields/documents.

# Eligibility Criteria

• Inclusion Criteria:

• Participants must be aged ≥60 years.
• Diagnosis of schizophrenia based on the International Classification of Diseases - 10th Edition (ICD-10) or Diagnostic and Statistical Manual of Mental Disorders - 5th Edition (DSM-5).
• Diagnosis must be made for ≥6 months, with clinical manifestations of schizophrenia (e.g., hallucinations, delusions, thought disorder, etc.).
• No history of severe acute psychiatric episodes or hospitalizations within the last 3 months prior to enrollment.
• Symptoms must be controllable, with no reliance on acute psychiatric intervention.
• Participants must be able to understand the study's purpose and procedures and provide written informed consent. If the participant is unable to provide full informed consent (e.g., due to severe cognitive impairment), informed consent must be obtained from a legal guardian.
• Exclusion Criteria:

• Schizoaffective disorder or bipolar disorder with psychosis.
• Elderly individuals with multiple chronic diseases but who still maintain good functional status and quality of life.
• Presence of severe cardiovascular diseases, liver or kidney dysfunction, cerebrovascular diseases, or other physical conditions that may affect treatment.
• Patients with contraindications to peripheral magnetic stimulation (PMS) treatment or EEG.