Transcranial low-level laser stimulation in near infrared-II region for brain safety and protection

TL;DR

This study demonstrates that near-infrared-II transcranial laser stimulation is safe and offers neuroprotective benefits without causing brain damage or impairing cognitive functions.

Contribution

The paper provides the first comprehensive safety assessment of NIR-II laser stimulation for brain applications, including neuroprotective effects and minimal side effects.

Findings

Significant reduction in neuron-specific enolase levels indicating neuroprotection

No structural or functional brain abnormalities observed

Participants reported minimal discomfort

Abstract

Background: The use of near-infrared lasers for transcranial photobiomodulation (tPBM) offers a non-invasive method for influencing brain activity and is beneficial for various neurological conditions. Objective: To investigate the safety and neuroprotective properties of tPBM using near-infrared (NIR)-II laser stimulation. Methods: We conducted thirteen experiments involving multidimensional and quantitative methods and measured serum neurobiomarkers, performed electroencephalogram (EEG) and magnetic resonance imaging (MRI) scans, assessed executive functions, and collected a subjective questionnaire. Results: Significant reductions (n=15) in neuron specific enolase (NSE) levels were observed after treatment, indicating neuroprotective effects. No structural or functional brain abnormalities were observed, confirming the safety of tPBM. Additionally, cognitive and executive functions were not impaired, with participants' feedback indicating minimal discomfort. Conclusions: Our data indicate that NIR-II tPBM is safe with specific parameters, highlighting its potential for brain protection.