Chronic traumatic encephalopathy (CTE) is a degenerative brain disease that is believed to result from repeated head injuries, particularly concussions. It is commonly associated with contact sports such as football, hockey, boxing, and rugby, but can also occur in other activities that involve repeated blows to the head.

CTE is characterized by the accumulation of an abnormal protein called tau in the brain. Tau forms clumps, known as neurofibrillary tangles, which gradually spread and cause damage to brain cells over time. This damage can lead to various cognitive, behavioral, and mood-related symptoms.

The symptoms of CTE can include memory loss, confusion, impaired judgment, aggression, depression, anxiety, impulse control problems, and eventually progressive dementia. However, the diagnosis of CTE can only be definitively made after death by examining the brain tissue under a microscope.


Dr Margaret Naeser from the Department of Neurology, Boston University School of Medicine, led a case-series study on the effects of brain photobiomodulation on former athletes with TBI and possible CTE.

This study features two components:

  • In-office treatments (3x a week, 6 weeks)
  • At-home treatments

Aims of Study

The primary aim was to present post-tPBM changes in cognition and behavior/mood for four, American-style ex-football players who had progressive symptoms of TES, possible CTE. The secondary aim was to present post-tPBM changes on MRI, including rs-fcMRI (SN, CEN, DMN), and magnetic resonance spectroscopy (MRS) for metabolites in cingulate cortex.

This study was approved by the Institutional Review Board, VA Boston Healthcare System. The MRI scan portion was approved by the IRB, Boston University School of Medicine where MRI scans were performed. Participants signed Informed Consent Forms; all methods were performed in accordance with relevant guidelines and regulations. This was an open-protocol, pilot study.

IDAge at Entry (y) RaceEducation (y) Highest DegreeAge First Exposure (y) Organized FootballTotal years Played FootballTotal years Played Pro-FootballPrimary Position PlayedChief Complaints at Entry
P165 Caucasian/White20 PhD, in Exercise Physiology after football10 Pop Warner141.5 CFLMiddle Linebacker, DefenseEmotional outbursts, depression, cognitive problems, poor memory, poor sleep
P255 Caucasian/White16 BA7 Pop Warner150Tackle, Offensive LinemanEmotional outbursts, cognitive problems, poor memory
P357 African American/Black16 BA14 High School168 NFLCornerback, Defense PositionEmotional outbursts, depression, cognitive problems, poor memory, poor sleep; chronic pain (15 surgeries during NFL); tinnitus
P474 Caucasian/White17 BS, Engineering13114 NFLDefensive End, and Offensive Lineman, all positionsEmotional outbursts, cognitive problems, chronic pain (4 hip replacements, 3 shoulder surgeries; 2 knee surgeries; 3 wrist/hand surgeries; 2 biceps surgeries)
  • Initial, in-office tPBM series

Each participant received an initial, in-office tPBM treatment series. This included 18 tLED treatments, each lasting approximately 22–40 min (3x/week, 6 weeks), with 48 h between treatments.

Three different tPBM devices/protocols were used. This is due to availability of more advanced devices, as the pilot study progressed. Common characteristics across all devices included application of NIR wavelengths (810 nm, 850 nm, or 870 nm) to scalp locations.

Case P1

P1 entered at age 65, with AFE to football at age 10. He played middle linebacker, defense position for 14 years including 1.5 years in the Canadian Football League. He received two tPBM treatment series, e.g., initial, in-office, and later, at-home.


In-Office tPBM treatments

At 1 week and 1 month after the final, 18th In-office treatment (compared to pre-treatment), P1 showed significant improvement on five tests/subtests: 1) CVLT for 16 words to remember: Short Delay Cued Recall; 2) and 3), Continuous Performance Test (CPT): decreased False Alarm Rate, and improved d prime, detectability; 4) and 5), Brief Visuospatial Memory Test (BVMT): Immediate Recall, and Recognition Discrimination Index (Recognition Hits minus False Alarms).

Behavior/mood questionnaires: Lower ratings indicate less impairment.

At the 2-months post-testing, however, there was decline, with significant improvement remaining only on one subtest, the BVMT, Recognition Discrimination Index. At the 2-months post-testing visit, P1 mentioned that return of emotional outbursts and depression was disturbing.

Within one week, he obtained a Vielight Neuro Gamma for at-home, self-treatment.

Later, at-home tPBM treatments

P1 self-used at home for 12 weeks with the Neuro Gamma device and a Vielight 633 Red (replaced by the Vielight MIP).

The two devices were often used simultaneously; no PBM treatments were performed one day a week.

Results: Later, at-home tPBM series

NP Tests: P1 re-gained most of the previous significant improvements present at 1 week or 1 month following the In-office series (but had lost after 2 months). Six tests/subtests showed significant improvement after the at-home series (compared to pre-treatment). This included for the first time, the Stroop, Trial 3, inhibition, suggesting improved executive function; and BVMT, Total Recall.

Behavior/mood questionnaires: There were also improved (lower) self-ratings on PTSD/PCL-C, BDI, SF-MPQ, and DEX. These were at near-normal levels

P1 continues to self-treat at home, to date for 4 years, and reports doing well. He has initiated tPBM treatment research with college football players at two universities with prominent football programs, as well as with retired, ex-football players experiencing cognitive and behavior/mood disturbances.

Case P2

P2 entered at age 55, with AFE to football at age 7. He played offensive lineman, tackle position for 15 years through college only. He received two tPBM series, initial, in-office, and later, at-home.

In-Office tPBM treatments

P2 was initially treated with a tPBM helmet, lined with red/NIR LED cluster heads.

Results: Initial, in-office tPBM series

NP tests: At 1 week or 6 weeks after the final, 18th in-office treatment (compared to pre-treatment), P2 showed significant improvement on six tests/subtests: 1)–4), CVLT four subtests: Total Trials 1–5; Short Delay, Cued Recall; Long Delay (20 min) Free Recall, and Cued Recall; 5), verbal fluency on COWAT; and 6) BVMT, Immediate Recall. At 12 weeks after the in-office series, five tests/subtests (CVLT) still showed significant improvement.

Behavior/mood questionnaires: At 1-week or 6-weeks post- the in-office tPBM series (compared to pre-treatment), improvements were present for PTSD/PCL-C, BDI, SF-MPQ, and DEX. At 12 weeks, however, there was an increase in PTSD/PCL-C, and some increased pain on the SF-MPQ rating to 9, the same as pre-treatment (Fig. 3BSupplementary Table 4B).

At 12 weeks after the in-office series had ended, P2 was disturbed by return of emotional outbursts. One week later, he obtained his own tPBM devices for at-home, self-treatment.

Later, at-home tPBM treatments

Like P1, P2 self-used at home for 12 weeks with the Neuro Gamma device and a Vielight 633 Red (replaced by the Vielight MIP).

The two devices were often used simultaneously; no PBM treatments were performed one day a week.

Results: Later, at-home tPBM series

NP tests: No in-person, NP cognitive testing could be performed after the 12-week, at-home tPBM series due to COVID restrictions.

Behavior/mood questionnaires: The questionnaires were mailed to his home after 12 weeks of home treatments. The PTSD/PCL-C, BDI, SF-MPQ, and DEX were again improved (lower ratings)

P2 reports he continues to self-treat at home, to date for two years, and is doing well. He remains employed in his own business.


Overall results are encouraging from this first, case-series report with four ex-football players meeting TES criteria for Possible CTE. Their cognitive and behavior/mood disturbances were well-managed and significantly improved following NIR tPBM treatments. To the authors’ knowledge, this is the first report of a potential treatment modality to mitigate symptoms of Possible CTE. Instead of continuing to worsen over time, these cases improved with tPBM. Without sham-control, a possible placebo effect is unknown. Significant correlations on rs-fcMRI with increased SN FC and improvements in executive function, attention, PTSD, pain, and sleep; and increased CEN FC with verbal learning and memory, less depression; plus increased NAA in ACC on MRS along with less pain and PTSD, all support a beneficial effect from tPBM.