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POLICY AND PRACTICE REVIEWS article

Front. Neurol.
Sec. Neurotechnology
Volume 15 - 2024 | doi: 10.3389/fneur.2024.1398894
This article is part of the Research Topic Photobiomodulation Therapy for Brain Disorders View all articles

Can Infrared Light Really Be Doing What We Claim It is Doing? Infrared Light Penetration Principles, Practices & Limitations

Provisionally accepted
Theodore A. Henderson Theodore A. Henderson 1,2,3,4,5*
  • 1 Neuro Luminance Corporation, Centennial, Colorado, United States
  • 2 Neuro Laser Foundation, Centennial, Colorado, United States
  • 3 Dr. Theodore Henderson, Inc, Denver, Colorado, United States
  • 4 The Synaptic Space, Inc, Denver, Colorado, United States
  • 5 International Society of Applied Neuroimaging (ISAN), Toronto, Ontario, Canada

The final, formatted version of the article will be published soon.

    Near infrared (NIR) light has been shown to provide beneficial treatment of traumatic brain injury (TBI) and other neurological problems. This concept has spawned a plethora of commercial entities and practitioners utilizing panels of light emitting diodes (LEDs) and promising to treat patients with TBI and other disorders, who are desperate for some treatment for their untreatable conditions. Unfortunately, an LED intended to deliver photonic energy to the human brain does not necessarily do what an LED pointed at a mouse brain does. There is a problem of scale. Extensive prior research has shown that infrared light from a 0.5-watt LED will not penetrate the scalp and skull of a human. Both the properties of NIR light and the manner in which it interacts with tissue are examined. Based on these principles, the shortcomings of current approaches to treating neurological disorders with NIR light are explored. Claims of clinical benefit from low-level LED-based devices are explored and the proof of concept challenged. To date, that proof is thin with marginal benefits which are largely transient. Extensive research has shown fluence at the level of the target tissue which falls within the range of 0.9 J/cm 2 to 15 J/cm 2 is most effective in activating the biological processes at the cellular level which underlie direct photobiomodulation. If low-level infrared light from LED devices is not penetrating the scalp and skull, then these devices certainly are not delivering that level of fluence to the neurons of the subjacent brain. Alternative mechanisms, such as remote photobiomodulation, which may underlie the small and transient benefits for TBI symptoms reported for low-power LED-based NIR studies are presented. Actionable recommendations for the field are offered.

    Keywords: transcranial, Traumatic Brain Injury, nir, photobiomodulation, NILT, Penetration, class IV laser, Brain

    Received: 11 Mar 2024; Accepted: 10 Jun 2024.

    Copyright: © 2024 Henderson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Theodore A. Henderson, Neuro Luminance Corporation, Centennial, Colorado, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.