Sarcopenia and frailty have been identified as negative predictors of health outcomes. Patients with stroke, traumatic brain injury (TBI), knee osteoarthritis (OA) and breast cancer commonly experience low physical activity levels in the chronic phase of recovery. This prospective study aims to explore the feasibility of multimodal screening and longitudinal tracking of various biomarkers from the acute to chronic phase of disease to determine the relationship with frailty outcomes.

A prospective longitudinal observational cohort study involving Asian populations is planned over 3 years. Enrolled participants with index conditions of acute stroke, TBI, knee OA and breast cancer will be recruited from rehabilitation hospitals and clinics and followed longitudinally. Reference thresholds from the Asian Working Group on Sarcopenia will be used. Variables include self-reported questionnaires, disease and comorbidity characteristics, anthropometric measurements, appetite questionnaires, muscle ultrasound (MUS), muscle/bone mass, blood biomarkers and markerless gait motion systems. In particular, physical performance (short physical performance battery and hand grip strength), sarcopenia (SARC-F questionnaire) and frailty assessment (FRAIL score, clinical frailty scale), four-region MUS, body composition analysis, dual X-ray absorptiometry, bone mineral densitometry, physical activity levels (International Physical Activity Questionnaire for the elderly [IPAQ-E], fitness trackers) and health-related quality of life assessment (EuroQoL-5D questionnaire five level [EQ5D-5L]) will be used. Blood biomarkers measuring metabolic health (eg, glycated haemoglobin, cholesterol, fasting glucose and 25-OH vitamin D) and inflammation (eg, Tumor Necrosis Factor-alpha [TNF-α] and Monocyte Chemoattractant Protein-1 [MCP-1]) will be measured at baseline. Data collection will take place at postrecruitment baseline (hospital admission), 1, 6 months, 12 months and 2 years postrecruitment (inpatient) and at postrecruitment baseline, 6 months, 12 months and 2 years postrecruitment (outpatient).

Ethical approval has been obtained from the National Healthcare Group Domain Specific Review Board (2023/00105). Findings will be disseminated through conference presentations and publication in scientific journals.

NCT06073106.

Deep brain stimulation (DBS) is a proven effective treatment for Parkinson’s disease (PD). However, titrating DBS stimulation parameters is a labourious process and requires frequent hospital visits. Additionally, its current application uses continuous high-frequency stimulation at a constant intensity, which may reduce efficacy and cause side effects. The objective of the AI-DBS study is to identify patient-specific patterns of neuronal activity that are associated with the severity of motor symptoms of PD. This information is essential for the development of advanced responsive stimulation algorithms, which may improve the efficacy of DBS.

This longitudinal prospective observational cohort study will enrol 100 patients with PD who are bilaterally implanted with a sensing-enabled DBS system (Percept PC, Medtronic) in the subthalamic nucleus as part of standard clinical care. Local neuronal activity, specifically local field potential (LFP) signals, will be recorded during the first 6 months after DBS implantation. Correlations will be tested between spectral features of LFP data and symptom severity, which will be assessed using (1) inertial sensor data from a wearable smartwatch, (2) clinical rating scales and (3) patient diaries and analysed using conventional descriptive statistics and artificial intelligence algorithms. The primary objective is to identify patient-specific profiles of neuronal activity that are associated with the presence and severity of motor symptoms, forming a ‘neuronal fingerprint’.

Ethical approval was granted by the local ethics committee of the Amsterdam UMC (registration number 2022.0368). Study findings will be disseminated through scientific journals and presented at national and international conferences.