Chapter 28 - Treatment of traumatic brain injury with near-infrared light

Abstract

Traumatic brain injury (TBI) is a physiological disruption of brain function induced by physical trauma either in the form of direct physical insult, rotational forces, or blast wave forces. While it has long been believed that mild TBI, also known as concussion, is benign, recent data has led to a new understanding that concussion/mild TBI can induce lasting and cumulative damage to the brain. Efforts to develop pharmacological treatments for TBI have largely failed. The study of transcranial near-infrared light therapy (NILT) has yielded insights into the potential of near-infrared light photobiomodulation as a method of treating TBI. Herein, the diagnostic workup is detailed, including neuroimaging, evaluation of polytrauma, assessment of olfaction and vestibular function, and assessing risk for cervicogenic headaches. The laboratory studies of NILT in animal models are reviewed. Emphasis is placed on understanding of the mechanism by which photobiomodulation occurs, and on scaling these experimental paradigms to the human condition. Clinical studies to date have yielded mixed results. A key factor in the success of clinical transcranial NILT may be delivering sufficient fluence to the target tissue. Our recent work with multiwatt NILT has shown robust and persistent changes in patients with TBI.