New research on light therapy shows promise for patients who have suffered repetitive head impacts and with possible CTE based on their medical history


This blog post is a special in-depth report by Concussion Alliance contributor and intern Julian Szieff, and Concussion Alliance co-founder Malayka Gormally.


Research on light therapy (photobiomodulation, PBM) by Margaret Naeser, PhD at the Boston VA Medical Center, and Boston University School of Medicine, Neurology, has expanded to encompass preliminary, but compelling research into the possible treatment of chronic traumatic encephalopathy, or CTE.

From Naeser’s poster presentation at the March 2019 International Brain Injury Association (IBIA) conference in Toronto.

From Naeser’s poster presentation at the March 2019 International Brain Injury Association (IBIA) conference in Toronto.

Concussion Alliance is following the research on this treatment closely, in part because the Vielight devices can be purchased by the general public and so are available for concussion patients to try. You can find more information about this treatment on our Light Therapy page.


At the International Brain Injury Association (IBIA) conference in Toronto (March 2019), Naeser presented two case studies which showed positive results from photobiomodulation treatments in two retired, professional football players who were diagnosed with cognitive decline and symptoms of possible CTE. One of the two cases incorporated baseline and follow-up fMRI scans, in addition to numerous clinical tests. Naeser’s abstract of the case studies was published in Brain Injury.



This research is the first study showing brain imaging changes on functional MRI scans after a series of photobiomodulation treatments in a retired professional athlete. The changes on fMRI scans occurred in tandem to changes in behavior, suggesting that the near-infrared photons were passing through scalp and bone, to reach the surface brain cortex. Thus, application of photobiomodulation to the scalp may be a possible treatment approach for CTE.


MRI connectivity.jpg

In terms of the history of her research, Naeser’s first study in 2014 (Naeser, Zafonte et al., 2014, Journal of Neurotrauma) found that a series of photobiomodulation treatments resulted in improvements in cognition (executive function and verbal memory), sleep, and quality of life in eleven patients with chronic, closed-head mild traumatic brain injury (mTBI). There was also a reduction of PTSD symptoms in the four cases who had problems with emotional outbursts. Throughout her research, Naeser has employed a variety of light therapy equipment made by different companies; treatments are applied by using red/near-infrared LED devices on the head, and newer studies have added a single, red LED, clipped into a nostril.


Larry Carr.jpg

In 2017, Naeser was approached by Larry Carr, PhD, a former BYU football player known for his defensive tackling who had been struggling for at least 10 years with symptoms highly resembling CTE, including emotional outbursts, depression, poor cognition and memory, as well as poor sleep. Seeking help with his symptoms and contemplating suicide, he asked Naeser to include him in her research. Carr became the first of Naeser’s two case studies with former professional football players who were possibly developing the progressive neurodegenerative disease, chronic traumatic encephalopathy (CTE).

At the Boston VA Medical Center, Naeser gave Carr a battery of baseline tests for depression, PTSD symptoms (emotional outbursts), sleep, memory, and other cognitive functions. Most importantly, Carr was given a functional MRI (fMRI) brain scan, which measures “functional connectivity” between specific areas of the brain cortex.


The results of these baseline tests reflected Carr’s self-reported symptoms. Carr was then given In-Office photobiomodulation therapy (using 2-inch diameter, LED cluster heads containing red and near-infrared diodes; MedX Health, Toronto). He was treated three times a week for six weeks.

Subsequently, follow-up test results for emotional outbursts, PTSD, depression, executive function, and verbal learning (including verbal memory) showed significant improvement. The fMRI brain scans showed increased connectivity between brain regions. Dr. Carr reported feeling that he felt like himself, for the first time in years. It is interesting to read Larry Carr’s description of his experience, and his wife Laurie Carr’s viewpoint, at their website FootballandtheBrain.com.


Intriguingly, and in line with some previous photobiomodulation research with dementia and Alzheimer’s Disease, Dr. Carr regressed considerably when the study required him to take eight weeks off from photobiomodulation therapy. This regression appeared in his subjective reporting (more emotional outbursts and depressed mood), and in objective test scores for executive function and verbal memory, as well as in his brain fMRI scans, which showed reduced “functional connectivity.”


Noting his resurgent symptoms, Dr. Carr bought his own photobiomodulation devices from Vielight; the Neuro Gamma (near-infrared diodes pulsed at 40 Hz); and an intranasal, red diode, nose clip. After three months of using his In-Home LED devices for 20 minutes, three times a week, he found his mood improving again.

Test results for the first retired NFL player. Click on a chart below to expand to full size.

Carr went back to Dr. Naeser, asking her to repeat the battery of tests, including the “functional connectivity” MRI brain scans. Naeser had not planned for an additional round of MRI brain scans and testing, but she acquired permission to repeat the MRI brain scans and testing. She found improvement in all the testing categories, including symptoms of PTSD, depression, executive function, and verbal memory, as well as sleep quality. There was also improvement in “functional connectivity” on the brain scans, especially in the left side of the brain (left hemisphere).


The second retired, professional football player (NFL), was treated in Dr. Naeser’s office, with the Thor Helmet photobiomodulation device (with red and near-infrared LED cluster heads which lined the inside of the Helmet). He showed the same kind of positive benefits from photobiomodulation when tested at one week and one month after the final, 18th LED treatment. This individual chose not to have brain MRI scans due to chronic pain.

In addition to the symptoms that the first football player presented with, the second football player had chronic shoulder pain and required two narcotic medications and Neurontin. His pain was reduced after the photobiomodulation, In-Office treatment series, and he was able to discontinue the two narcotic pain medications.


There was also a reduction in his tinnitus, from a level of moderate to only mild, after the In-Office photobiomodulation treatment series. He did not return to the office for further testing after the one week and one month testing times. His comment at that time was, “I don’t want to go back to where I was before I came here. I need to have continued photobiomodulation treatments.” He then purchased his own Vielight Gamma, headframe device (with near-infrared diodes), the same as what the first football player has for At-Home photobiomodulation treatments. His anecdotal reports to Dr. Naeser’s office are that he continues to do well with his At-Home LED treatments, now ongoing for ten months.


In her scientific poster, Naeser discusses potential reasons why the first football player showed regression after discontinuing the photobiomodulation treatments for eight weeks after the final, 18th In-Office treatment. This is a pattern also seen with dementia patients who have a progressive neurodegenerative disease, likely Alzheimer’s Disease (Saltmarche, Naeser et al., 2017, Photomedicine and Laser Surgery). Other TBI cases (without repetitive head impacts) continue to maintain gains made after the final, 18th In-Office, photobiomodulation treatment. These other TBI cases even improved, after two months without any additional, intervening photobiomodulation treatments (Naeser, Zafonte et al., 2014, Journal of Neurotrauma). They did not have an ongoing progressive neurodegenerative disease.

The results of these case studies are hopeful, keeping in mind the inherent limitations of case studies – i.e., small sample size, and no control for the placebo effect.


Dr. Naeser, Vielight headset placement.

Dr. Naeser, Vielight headset placement.

To that effect, Dr. Naeser will lead a new study of 20 patients with closed-head, traumatic brain injury, making use of the Vielight Neuro Alpha device (pulsed at 10 Hz) as an At-Home treatment, avoiding the inherent complications of thrice-weekly, In-Office visits to a clinic. The study will be controlled, meaning the participants will be divided into a treatment group and a “sham” treatment group. All participants will receive the real treatments, at some point during the study. Naeser’s study will make use of fMRI scans before and after treatment. Vielight has an article that mentions this new study of 20 patients, and also discusses the two case studies of the retired professional football players.


While researchers including Dr. Naeser are urging for further research, the potential for this new therapy is promising. Additional research is being considered for biological research into the mechanisms by which light induces these functional connectivity changes in the brain. Continuing research will also address which modalities of light therapy have the best therapeutic efficacy for acute (recent) and chronic (long-term) brain injury symptoms.


We thank Margaret Naeser, PhD for assistance with editing parts of this summary.

The Vielight devices fit within the FDA category of “Low-Risk Devices, General Wellness;” and no medical claims are made in this category.

This article is for information purposes only. No medical claims are made. By providing the information contained herein we are not diagnosing, treating, curing, mitigating or preventing any type of disease or medical condition. Before beginning any type of treatment regimen, it is advisable to seek advice of a licensed healthcare professional.

Conflict of Interest Disclosure: Vielight, Inc.,Toronto, funds some of Professor Naeser's transcranial LED research with traumatic Brain Injury (TBI). The materials presented here do not represent the views of the Department of Veterans Affairs or Boston University School of Medicine. Professor Naeser has no personal, financial conflict of interest to declare.