The crowd roared, silencing the concussive crack of colliding helmets as players smashed through the opposition–desperate to reach the goal line. Heads down and muscles burning, the players continued their forward assault–unaware that each impact with opposing helmets ignited a cascade of changes deep within the brain that would slowly lead to memory loss, confusion, irritability, and paranoia.
Neuroscientists are only beginning to understand the complex pathology of chronic traumatic encephalopathy (CTE), which can manifest as a result of chronic traumatic brain injury (TBI) or blows to the head. According to Mayo Clinic, nearly 2% of the US population experience lasting disability from TBI and evidence suggests that combining treatments–like pharmaceuticals, nutraceuticals, counseling, and hyperbaric oxygen therapy–does little to reverse damage in the brain.
Regenerative medicine may succeed where traditional methods fail by harnessing the body’s own repair mechanisms to regrow cells and heal damaged tissues. The results of a 2015 study in the journal Neuropsychiatric Disease Treatment illustrate how near-infrared (NIR) laser phototherapy might be a viable alternative treatment for chronic TBI.
In this case series 10 patients with chronic to mild TBI–including five combat veterans, a woman who sustained hypoxic encephalopathy during childbirth, and a survivor of domestic violence–were treated with 10-20 sessions of NIR light therapy using one of two Class IV lasers–the LT100 laser at wavelengths of 810/980nm and Diowave laser at 810nm.
The effects were felt immediately. A few days after treatment patients experienced significant improvement in their mental health–including anxiety, depression, irritability, and insomnia–and physical symptoms–like headaches, fatigue, memory loss, suicidal ideation, and substance abuse. Seven months later, objective evaluations of brain functioning revealed that patients continued to show cognitive improvement–indicating that symptoms are unlikely to regress.
Photobiomodulation is an emerging tissue regeneration technique that uses light therapy in the red/NIR region–600nm-1,200nm–of the electromagnetic spectrum to activate a healing response in the human body. Longer wavelengths in the NIR range have been experimentally shown to travel deeper in the body–penetrating skin, subdermal tissue, and bone–to reach the brain.
As NIR light travels through the brain, it interacts with proteins nestled in the membranes of tiny organelles called mitochondria. These organelles produce ATP–a molecule necessary for cellular metabolism, function, and repair.
Photosynthesis vs. Photobiomodulation
Many organisms use light to generate energy and expedite healing. In plants, organelles called chloroplasts convert light energy into chemical energy–a process called photosynthesis. Inside chloroplasts, proteins called reaction centers absorb light using green chlorophyll pigments. Each chlorophyll pigment absorbs one photon and kicks off one electron. This energy input allows electrons to flow down the electron transport chain causing complexes–such as cytochrome–to pump protons across a membrane to create an energy gradient for the production of ATP.
Human mitochondria use cytochrome c oxidase–a membrane protein complex that is part of the electron transport chain–to produce ATP. When cells accumulate damage, excess nitric oxide (NO) binds cytochrome c oxidase and shuts down ATP production. Without ATP, cells–like neurons in the brain–are unable to repair themselves and begin to die, leading to widespread tissue degeneration.
Just like plant chloroplasts, human cytochrome c oxidase absorbs NIR photons during laser therapy and kick-off excess NO–restarting the electron transport chain and increasing ATP production. Additionally, the released free NO–a known vasodilator–improves blood flow in the brain, delivering critical nutrients and oxygen for cells to carry out tissue repair and begin mediating the damage.
While far from conclusive, this case series offers evidence that NIR laser therapy could provide relief for a wide range of patients experiencing symptoms associated with TBI and CTE.
For more information:
Morries LD, Cassano P, Henderson TA. Treatments for traumatic brain injury with emphasis on transcranial near-infrared laser phototherapy. Neuropsychiatric Disease and Treatment. 2015;11:2159-2175. doi:10.2147/NDT.S65809.
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