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Frequency-Dependent Effects of Transcranial Photobiomodulation on Cortical Excitability

NCT07707284 · Status: NOT_YET_RECRUITING · Phase: PHASE1 · Type: INTERVENTIONAL · Enrollment: 20

Last updated 2026-07-28

No results posted yet for this study

Summary

This study aims to investigate the frequency-dependent effects of near-infrared (NIR) transcranial photobiomodulation (tPBM) on human cortical excitability and fine motor performance. A cohort of 20 healthy adult volunteers (aged 18-35 years) will participate in a randomized, double-blind, sham-controlled, single-center study utilizing a within-subject, five-arm crossover design. Each participant will undergo five distinct experimental conditions separated by a strict washout period: active Continuous Wave (CW) tPBM, active pulsed tPBM at three neural oscillation frequencies (10 Hz, 40 Hz, and 100 Hz), and an inactive Sham comparator. All interventions will be delivered using a clinical-grade near-infrared device.

To isolate the specific effects of pulse frequency from overall energy delivery, the total energy dose (cumulative Joules) and total exposure time will be held perfectly constant across all active arms. The pulsed conditions will keeps the average irradiance and cumulative fluence identical to the continuous wave mode. Cortical excitability will be assessed via single- and paired-pulse Transcranial Magnetic Stimulation (TMS) protocols over the primary motor cortex (M1). Fine motor performance will be quantified using a smartphone-based Finger Tapping Test (FTT). Safety and systemic parameters will be tracked using the Systematic Assessment for Treatment Emergent Events - Systematic Inquiry (SAFTEE-SI) and vital signs. The central hypothesis is that distinct modulation frequencies will differentially influence corticospinal excitability and motor execution, independent of the total energy delivered.

Conditions

  • Healthy Volunteers (HV)
  • Transcranial Photobiomodulation
  • Cortical Excitability

Interventions

COMBINATION_PRODUCT

Transcranial Photobiomodulation

Transcranial photobiomodulation (tPBM) is a non-invasive, non-thermal neuromodulatory modality that utilizes low-power coherent (laser) or non-coherent (light-emitting diodes, LEDs) light sources within the red (lambda = 600-700 nm) and near-infrared (NIR; lambda = 700-1100 nm) spectral windows to modulate cortical function. Structurally tailored to penetrate superficial anatomical barriers-including the scalp, skull, and meninges-tPBM delivers photons directly to the cerebral cortex.

Sponsors & Collaborators

  • Federal University of Rio Grande do Sul

    collaborator OTHER

  • Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.

    collaborator OTHER_GOV

  • Hospital de Clinicas de Porto Alegre

    lead OTHER

Principal Investigators

  • Marco A Caldieraro, Doctor · Federal University of Health Science of Porto Alegre

Study Design

Allocation
RANDOMIZED
Purpose
DEVICE_FEASIBILITY
Masking
DOUBLE
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
35 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2027-05-31
Primary Completion
2028-05-31
Completion
2028-07-31

Countries

  • Brazil

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07707284 on ClinicalTrials.gov