Can Light Therapy Help After a Traumatic Brain Injury? What an Early Safety Trial Found

Traumatic brain injury has very few proven treatments, which is why this trial — one of the first of its kind — drew attention even though it was designed primarily to test safety and feasibility, not to prove a cure.

What the research looked at

Published in JAMA Network Open in 2020, this randomized clinical trial enrolled 68 patients with moderate traumatic brain injury shortly after their injury. Participants were randomly assigned to receive either near-infrared transcranial light therapy or a sham treatment. Researchers tracked safety and adverse events, then used quantitative MRI to measure changes in the brain's white matter, alongside neurocognitive testing, up to three months after injury.

What they found

The treatment was feasible and safe, with no adverse events reported among patients who completed sessions. In the weeks following injury, MRI scans showed statistically significant differences in white matter diffusion measurements between the light-treated and sham groups — evidence that the light therapy was measurably affecting brain tissue, not just a placebo effect.

What this means in practice

This is an early-stage trial designed to answer "is this safe and does it do anything measurable to the brain?" — not "does it improve someone's recovery." The imaging changes are a genuinely interesting biological signal, but they aren't the same as a proven improvement in cognitive function or long-term outcomes, and larger trials would be needed to establish that. It's an encouraging first step for an area of medicine with very limited treatment options, published in a well-regarded journal — but it's not yet evidence that light therapy treats traumatic brain injury.