Exploring cortical excitability modulation to promote cognitive resilience in aging: an rTMS study protocol

Promoting cognitive resilience in aging is essential for preserving autonomy and quality of life. Non-invasive brain stimulation techniques, such as repetitive transcranial magnetic stimulation (rTMS), have shown promise in enhancing neuroplasticity and cognitive functioning in older adults. This study protocol outlines the methodological framework for an investigation designed to examine whether high-frequency rTMS applied over the left dorsolateral prefrontal cortex (DLPFC) can modulate cortical excitability (CE) and characterize changes in cognitive and emotional functioning in healthy older individuals. The protocol provides detailed descriptions of stimulation parameters, safety monitoring procedures, and assessment tools. Cortical excitability will be measured using transcranial magnetic stimulation-derived motor-evoked potentials (MEPs), while cognitive and emotional outcomes will be assessed with a comprehensive neuropsychological battery. A preliminary feasibility phase with four participants was conducted to refine procedures and assess tolerability, safety, and data acquisition reliability. The study aims to determine the feasibility and signal characterization of cortical excitability modulation within a crossover framework and to explore the potential relationship between CE modulation and behavioral outcomes. Observations from this pilot phase will inform procedural refinement and the design of a larger ongoing trial.