Photobiomodulation (PBM) in Concussion and Traumatic Brain Injury (TBI) Treatment:
A Summary of ongoing Human Studies
Photobiomodulation (PBM), also known as low-level light therapy, has been investigated extensively as a potential treatment for several conditions that don’t respond to conventional approaches. Human model research into PBM’s efficacy in treating concussions and Traumatic Brain Injury (TBI) related symptoms is ongoing, with several key researchers leading studies to assess its impact on cognitive function, neuromuscular control, and mental health. This summary highlights notable advancements in the field of Photobiomodulation that laid foundation for human studies, and the researchers behind them.
Leading Researchers and Their Contributions
In 2002, I began a Clinical Fellowship with Canadian medical-scientist, Fred Kahn, MD a retired vascular surgeon and developer of the Bioflex Laser Therapy System I have used in clinic for 23yrs. A pioneer in the field of Photobiomodulation (PBM) who emerged as an alternative pain management specialist, Dr. Kahn attracted a global audience of early PBM adopters including researchers and doctors seeking knowledge, and patients seeking Care. Within the population of early adopters we received in our Toronto clinic, were patients who presented with unresolved complex neurologic and orthopaedic conditions, and personnel from major professional sports teams with a steady flow of individual retired and active athletes seeking to recover from injuries, new and old. As part of my role, I conducted clinical assessments on these early PBM adopters, which provided unique and meaningful insight. In addition to serving a practical clinical purpose, it helped us understand the motivation that compelled people who had received other forms of Care, sometimes from other parts of the world - to seek out PBM.
Over the course of my four year Fellowship under Dr. Kahn, I gained the additional privilege of collaborating with early PBM scientific investigators responsible for the deep and important research that supported the modern boon of PBM. Notably, Tiina Karu, Russian Academy of Sciences shared insights about her foundational discoveries, including her seminal work that led to understanding the mechanism and action of light spectra and electron transport in the mitochondria of the cell. Her research demonstrated how light-activated signalling pathways influence gene expression, nitric oxide release, and neuroprotection. Her work shaped PBM’s modern applications in wound healing, pain management, and neurological recovery and laid the scientific foundation for my own interest in PBM’s clinical use in treating traumatic brain injuries, neurodegenerative diseases, and musculoskeletal conditions.
Dr. Mary Dyson was a key contributor to my early understanding about PBM as a modality.
She is an Emeritus Reader in the Biology of Tissue Repair at King’s College London, where her research has significantly advanced the understanding of tissue repair mechanisms, particularly in wound healing. She co-authored works such as “Principles of Wound Care,” contributing to the field’s body of knowledge and investigated the effects of light on the cells involved in wound healing with research that has had a lasting impact on wound care and rehabilitation broadly, that influences modern physiotherapy and dermatology. During her visits to our clinic she eloquently described her work, which provided a scientific basis for using light therapy to accelerate healing, reduce inflammation, and enhance tissue repair, making these treatments widely used in sports medicine, post-surgical recovery, and chronic wound management.
I met Chukuka Enwemeka, Emeritus Editor-in-chief of Photomedicine and Laser Surgery and distinguished researcher, former Dean of Health Sciences at New York Institute at a PBM symposium where he described the application of PBM as an effective treatment against pathogens. As I review this document almost ten-years after that meeting, the world has been impacted by the lethal Covid-19 pathogen. In line with Dr. Enwemeka’s important work, Health Canada approved PBM in 2020 for the management of Covid, due its proven efficacy in reducing the lethality of Covid-related pathogenic cytokine storm.
Jan Turner, co-author of Laser Therapy Clinical Practice and Scientific Background is a key figure in establishment of PBM protocols, education, and clinical implementation have helped establish PBM as a mainstream therapeutic modality in rehabilitation, sports medicine, who influenced our protocol development. Dr. Juanita Anders, a NZ-based PBM researcher and professor of anatomy, physiology and genetics investigated efficacy of PBM in spinal cord injury which, advanced the use of PBM in neurology, pain management, and spinal cord injury rehabilitation. Her research has provided scientific validation for PBM in neuroprotection and nerve regeneration, influencing its adoption in clinical settings for neurological disorders, chronic pain, and traumatic injuries
Early introduction to leading researchers during my Fellowship period fuelled my own professional curiosity and independent consultation including with the most widely published PBM researcher, Michael Hamblin, of Harvard Medical Wellman Photomedicine and Massachusetts General Hospital. His work is central to the scientific-understanding about light’s mechanism of action in wound healing and various brain disorders, including TBI and SCI. Through Dr. Hamblin, I was introduced to Professor of neurology and TBI PBM researcher, Margaret Naesar, of Boston University who has conducted human clinical trials with Anita Saltmarche, a Canadian Nurse, clinical researcher and PBM specialist.
Human Studies
Dr. Michael Hamblin has extensively studied PBM’s mechanisms and applications. In a 2017 meeting with Dr. Hamblin at Harvard, he described PBM’s potential role in treating Traumatic Brain Injury (TBI, and mTBI/concussions) and stroke in humans that referred to a Study he had completed, highlighting its effects on mitochondrial function, inflammation reduction, and neuroprotection. His work has provided a strong foundation for further clinical investigations into PBM’s potential benefits for brain health (Hamblin, 2017 Reference:
Dr. Margaret Naeser, who, along with Anita Saltmarche, has conducted multiple studies on PBM’s effects in TBI patients. In 2011, Naeser published case reports documenting two chronic TBI patients who underwent transcranial LED treatments (870 nm and 633 nm wavelengths), resulting in improved focus and memory. In 2014, she expanded this research with an open-protocol study involving eleven chronic mTBI patients, demonstrating that PBM therapy led to better sleep quality, reduced PTSD symptoms, and overall cognitive improvements (Naeser et al., 2014 Reference: https://www.mdpi.com/2073-4409/13/5/385)
Anita Saltmarche, a specialist in PBM applications, has treated patients with brain injuries, demonstrating positive outcomes in cognitive function and quality of life for TBI patients. Her work has contributed to clinical applications of PBM in concussion rehabilitation (Saltmarche et al., 2024 Reference: https://www.concussionalliance.org/light-therapy-photobiomodulation)
I met Lew Lim in 2017 when he described his work in TBI, PTSD and his relationship with Boston University Researchers. Dr. Lim is a significant contributor to PBM research, and a Canadian scientist who developed a PBM device, which has been used in multiple studies, including those by Naeser and Dr. David Tate. Lim’s 2024 review explored how PBM modulates TBI-related cellular mechanisms, further reinforcing its therapeutic potential in neurorehabilitation (Lim, 2024).
Dr. Paolo Cassano, an assistant professor at Harvard Medical School, has explored PBM’s effects on mood and cognitive disorders, with a particular focus on its potential for treating TBI-related psychiatric conditions. His clinical studies suggest that near-infrared light therapy could be beneficial in managing symptoms such as anxiety, depression, and cognitive impairment following a concussion
Reference: https://www.mdpi.com/2304-6732/11/3/260
In addition to these individual researchers, the University of Utah research team has been conducting a long-term study assessing PBM’s effects on individuals with a history of concussions or repetitive head impacts. Their research involves participants using PBM therapy every other day for 20 minutes over two years to evaluate its impact on brain health and recovery.
Concussion Alliance: https://www.concussionalliance.org/blog/photobiomodulation-improves-neuromuscular-deficits-related-to-concussions-and-repetitive-head-impacts
Dr. David Tate and his colleagues have also investigated PBM’s role in neuromuscular control for individuals with concussions or repetitive head acceleration events. In a 2024 clinical study, participants underwent an eight-week PBM protocol using a specialized PBM device, which led to significant improvements in reaction time, balance, and grip strength, suggesting that PBM may enhance motor function and coordination in TBI patients (Tate et al., 2024 Reference: https://www.concussionalliance.org/blog/photobiomodulation-improves-neuromuscular-deficits-related-to-concussions-and-repetitive-head-impacts)
In addition to investigating PBM’s role in TBI, Dr. Praveen Arany at the University at Buffalo has explored PBM’s mechanisms of action in broad applications. His research found that red and near-infrared light therapy reduced skin damage and inflammation in cancer patients, indicating that PBM may have further potential in tissue healing and neuroprotection (Arany et al., 2024).
Other researchers have examined PBM’s systemic effects on the body. Dr. Glen Jeffery from University College London conducted a metabolic study in which red-light therapy applied to the back led to reductions in peak blood-sugar levels, suggesting potential neurological and metabolic benefits that may translate to brain health improvements (Jeffery et al., 2024 Reference: https://pubmed.ncbi.nlm.nih.gov/38378043/)
Finally, Dr. Larry Carr, a former football player turned researcher, has conducted pilot trials investigating PBM’s effectiveness in managing chronic traumatic encephalopathy (CTE)-like symptoms. His early findings indicate that PBM therapy may improve cognitive and neurological symptoms in former athletes with repeated head injuries, providing a promising avenue for long-term TBI treatment.
Conclusion and Future Directions
Collectively, these studies suggest that PBM holds significant promise in treating concussion-related symptoms, including cognitive function, PTSD, neuromuscular control, and mood disorders. However, while initial research and small-scale clinical trials have yielded encouraging results, larger-scale, controlled trials are necessary to standardize treatment protocols and confirm PBM’s efficacy for widespread clinical use. As research continues, PBM could emerge as a non-invasive, effective therapeutic option for individuals suffering from the long-term effects of concussions and TBIs.
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