Transcranial Near-Infrared Light May Treat Brain Injury and Neurodegeneration
At the 2021 meeting of the Society of Biological Psychiatry, there was a symposium on treatment with near-infrared light chaired by researchers Paolo Cassano and Dan Iosifescu. The treatment is known as transcranial photobiomodulation (PBM) with near-infrared light. A device worn on the head delivers infrared light that penetrates the cerebral cortex and can modulate cortical excitability. It has a variety of effects including promoting neuroplasticity, improving oxygenation, and decreasing inflammation and oxidative stress.
A number of studies exploring the possibility that PBM could be used as a clinical treatment for conditions such as depression, brain injury, or dementia were presented at the symposium.
Researcher Lorelei Tucker discussed promising findings from an animal model in which rats with stroke or brain injuries showed improvement after being treated with PBM.
Cassano discussed studies aimed at refining which brain areas should be targeted with PBM and how much light should be delivered in order to improve depression. In double-blind, sham-controlled studies in people with major depression, targeting the dorsolateral prefrontal cortex with PBM improved their symptoms.
Researcher Benjamin Vakoc discussed a study of low-level light therapy (LLLT) using near-infrared light compared to a sham procedure in 68 people with moderate traumatic brain injury. The researchers used magnetic resonance imaging (MRI) to assess changes in white matter in the brain over time in people recovering from an acute brain injury. Patterns of changes in white matter were different for those who received LLLT compared to those who received the sham procedure.
Researcher Linda Chao described a very small study to determine whether PBM could improve symptoms of dementia. Four patients received typical dementia care while four others underwent home treatments with the commercially available Vielight Neuro Gamma device, which delivers PBM via both the scalp and an insert in the nose. After 12 weeks, the PBM group showed improvements in cognition and brain connectivity.
Editor’s Note: We will be watching the literature to follow advances in this promising novel method of neuromodulation.
Following Collisions, High School Football Players with No Signs of Concussion May Still Have Neurological Impairment
In a small 2014 study in the Journal of Neurotrauma, researcher Thomas M. Talavaga and colleagues reported that repeated head trauma that did not produce concussion symptoms was still associated with neurocognitive and neurophysiological changes to the brain in high school football players.
The longitudinal study tracked ‘collision events’ experienced by 11 teens who played football at the same high school. The young men also completed neurocognitive testing and magnetic resonance imaging (MRI) scans of their brains over time.
The researchers expected to see the participants fall into two categories: those who had no concussions and normal neurological function, and those who had at least one concussion and subsequent neurological changes. They ended up observing a third group: young men who had not exhibited concussion symptoms, but nonetheless had measurable changes to their neurological functioning, including impairments to visual working memory and altered activation of the dorsolateral prefrontal cortex. Young men in this last group had had more collisions that impacted the top front of the head, directly above the dorsolateral prefrontal cortex.
The authors suggest that the discovery of this third category mean that some neurological injuries are going undetected in high school football players. The players who are injured in this way are not likely to seek treatment, and may continue playing football, risking more neurological brain injury or brain damage with subsequent collisions.
