This study investigates the immediate effects of different parameters (frequency and intensity) of trans-spinal magnetic stimulation (TsMS) on cortical excitability in healthy individuals. Using a randomized, double-blind crossover design, the research aims to identify optimal stimulation protocols for modulating neural activity. Outcomes include measurements of motor-evoked potentials (MEP), intracortical inhibition (ICI), and facilitation (ICF). Findings may enhance non-invasive therapeutic strategies for neurological disorders.

This clinical trial comprises one arm: it evaluates trans-spinal magnetic stimulation (TsMS) applied at the C7 vertebral level, testing three frequencies (1 Hz, 10 Hz, and 25 Hz) and three intensities (90%, 100%, and 110% of the resting motor threshold) across sequential phases.

Methods: The study is a crossover, double-blind trial in which healthy adults (aged 18-40 years) undergo pre- and post-intervention assessments of cortical excitability (MEP, ICI, and ICF). Statistical analyses will be performed using ANOVA or Friedman tests (SPSS v.26).

The results will clarify whether the neuromodulatory effects of the stimulation are parameter-dependent and will guide future rehabilitation protocols for neurological conditions.

The research was approved by the Ethics Committee of the Federal University of Pernambuco (Resolution 466/12). All data will be stored securely for the next five years.

Healthy adults aged 18-40 years, of both sexes; right-handed (confirmed via the Edinburgh Handedness Inventory); and for women, consistent use of contraceptive medication to mitigate hormonal influences on nervous system excitability.

Exclusion Criteria:

Pregnancy; history of seizures or epilepsy; metallic implants in the head, spine, face, or heart; diagnosed neurological or musculoskeletal conditions that could interfere with assessments or interventions; or use of substances that alter nervous system excitability.