In science fiction, lasers are portrayed as these all powerful weapons of death. Fatally blowing the opposition into smithereens with a single shot. However, modern neuroscience proposes a more nuanced usage of this infamous tool.
Utilizing lasers to heal the body instead of killing it, Transcranial photobiomodulation (tPBM) is another proposed treatment for various neurological diseases. In numerous studies analyzing non-invasive penetration of both human and non-human skulls with red and near-infrared light, scientists have linked this practice to cognitive improvement and better mood regulation. Even claiming that such treatments could be used to fight against strokes or Alzheimer’s disease. However, is this declaration accurate or purely speculation? Let’s find out!
Typically, pharmacological treatment is administered when treating various neurological conditions. However, these treatments also have difficulty passing the blood brain barrier (BBB), limiting its effects on the brain. Drug therapies also run into the issue of giving patients adverse side effects, some of which may need further medication to resolve.
Transcranial photobiomodulation (tPBM) is a noninvasive technology proposed around 50 years ago, aiming to close the effectiveness gap where traditional drug therapies fall short.
It works by beaming red to near-infrared light (NIR), 600 to 1300 nanometers, directly into brain tissue without cracking open the skull. Once absorbed, neuronal mitochondrial activity is boosted after the cytochrome c oxidase enzyme enables increased adenosine triphosphate (ATP) production. ATP aides in transferring energy within cells for survival, growth, and reproductive purposes. Increased ATP production has also been seen over the past few decades to trigger additional neuroprotective signaling, stimulate the brain waste removal system (BWRS) and decrease the oxidative stress that contributes to several neurodegenerative diseases.
tPBM has also been tested as a possible approach to treating those suffering from an ischemic stroke. A stroke that results in damage to the blood brain barrier, making it easier for blood cells and neurotoxins to enter the brain which trigger neuroinflammatory responses and further brain damage.
According to a study by Hae In Lee and colleagues, applying tPBM within four hours after a mouse model suffered an ischemic stroke improved long-term recovery and encouraged cellular growth. Suggesting that tPBM may be most effective during this time frame for ischemic stroke cases.
In the case of Alzheimer’s disease, tPBM seems to show promise in treating the Beta Amyloid plague build ups commonly found to slow down cognition and memory circuits in mouse models of the disease. Especially when paired with deep sleep according to a study by Semyachkina-Glushkovskaya O. and colleagues.
When tested on healthy patients, there are reported improvements to working memory, reaction time and executive function after varying amounts of sessions. Though these effects are usually rather minor and sometimes only last for a short period of time.
According to a Nature article by Naomi L. Gaggi, tPBM’s biological effects are better understood than other transcranial devices on the market. Also seeing that on top of its application on its own, tPBM has functioned adequately when paired with magnetic resonance imaging (MRI) and other neuroimaging devices observing the efficacy of the technology without any safety concerns. The technology is also cheaper and easily accessible compared to other treatments.
Though relatively safe, tPBM helmets aren’t without side effects and could result in a heated scalp, a mild headache and temporary nausea. It is recommended to avoid excessive exposure to the technology, protect eyes from laser exposure, use the device with caution if on photosensitizing drugs or have a condition that makes you more prone to photosensitivity and to consult medical approval first before it’s placed over implanted electrical devices.
Another problem with these devices is due to their accessibility. While it’s good that a promising treatment method such as this can be widely accessed, there’s also the problem of false advertisements and overly sensationalized claims made to encourage users to buy it. Some may advertise it as a wellness product, while others claim it will cure a problem and cherry pick studies with small participant sizes that show moderately positive results.
These products also vary in quality. Where some might have lasers as strong as ones used in clinical research, others on the market are essentially a basic LED light glued onto a helmet.
Even fellow clinicians could be fooled by these low-grade dupes. They must be checked for accurate wavelengths, specific power output, safety features which shut off after long periods of time and sense the temperature in case the wearer begins to overheat as well as many other features in high-quality helmets.
All that aside, tPBM is still an emerging field that requires further studies on human participants to determine if there’s any major reactions that differ between us and our other animal counterparts. Scientists also still wonder about the long-term effects of these devices, which other treatments it works best with and if physiological differences in head shape could change its efficacy.
This is to say tPBM technology is far from being the miracle some may claim it is. Though an impressive treatment method, there is still a long way to go before reaching the impossibly high expectations shared online or in popular sci-fi media.
Featured image: Photo by Markus Kammermann on Unsplash
Edited by James Sutton
