Photobiomodulation and the Brain

I have already written in this space about the promise of photobiomodulation (PBM) for traumatic brain injury and Alzheimer’s. But I may have been too limited in my vision for PBM and the brain. A 2016 paper published in the journal BBC Clinical reviewed the research on PBM and the brain, saying in part, “The brain suffers from many different disorders that can be classified into three broad groupings: traumatic events (stroke, traumatic brain injury, and global ischemia), degenerative diseases (dementia, Alzheimer’s and Parkinson’s), and psychiatric disorders (depression, anxiety, post traumatic stress disorder). There is some evidence that all these seemingly diverse conditions can be beneficially affected by applying light to the head.”

The author, Michael R. Hamblin, who is attached to the Wellman Center for Photomedicine of Massachusetts General Hospital in Boston, reviewed the relevant research — both animal and clinical — and found that PBM produced good outcomes for stroke (both acute and chronic), traumatic brain injury, Alzheimer’s, Parkinson’s, and psychiatric disorders, including depression and anxiety. He then drew up a table of brain disorders that could be, in principle, treated with PBM. They include traumatic disorders (such as stroke, injury, ischemia, and coma), neurodegenerative disorders (such as dementia, ALS, progressive aphasia, and Creutzfeld-Jakob, also known as “Mad Cow” disease), psychiatric disorders (such as bipolar, insomnia, addiction, PTSD, and psychosis), and neurodevelopment disorders (including autism and ADHD). In all, he catalogued 23 conditions he expects PBM to treat, none of which has a reliable “cure” at present.

He calls for inexpensive LED helmets to be developed for home use to provide widespread access to treatment for all kinds of patients with brain disorders.

This is all very exciting, especially for people working in neurobiology and neuropathology. But Hamblin’s most exciting point related not to disorders, but to “cognitive enhancement” of healthy individuals. Mouse studies have showed improved maze running abilities after PBM, as well as the prevention of reemergence of “extinguished conditioned fear responses” — that is, it made mice braver. Human studies, on the other hand, led to measurable improvement in “a psychomotor vigilance task (PVT), a delayed match-to-sample (DMS) memory task, and the positive and negative affect schedule (PANAS-X) to show improved mood.” Furthermore, another clinical study demonstrated improvement in human executive function.

Hamblin actually takes issue with the research community’s consensus on the way PBM achieves its effects. Most researchers, he said, attribute PBM’s results to “increases in cerebral blood flow, greater oxygen availability and oxygen consumption, improved ATP production and mitochondrial activity.” But Hamblin says the effects described in the literature are too long-lasting to be explained that way. The duration of the effects can only be explained by “activation of signaling pathways and transcription factors that cause changes in protein expression.”

It will probably be some time before the mechanism of PBM is fully explained. Fortunately, PBM is known to have very little risk, so if you’re suffering from a brain disorder, or simply want to enhance your cognitive abilities, you don’t have to wait for the explanation. Book a PBM session with Peak Recovery & Health Center and see for yourself if all this research can benefit you.

Image: “brain 13” by affen ajlfe, credit Public domain.