Comment I believe in (some) red light (Score 1) 55
OK, this is my personal anecdote and might or might not be related to the brain injury treatment - but I'm confident more and more red (or more accurately: various long wavelengths) light therapies will get proven in future.
So I'm a middle aged male and miss a box-jump at Crossfit one fine day. Superficial shin injury that turns out to not want to heal, turning nasty. Doctor explains as we get older, we have less blood circulation in the lower limbs especially. Sedentary IT job doesn't help either. Lots of cellulitis (tissue inflammation around the wound) and at a stage it turns septic too. Get on first-name terms with the nurses at a nearby wound-care clinic. Eventually its getting onto a month with only marginal improvement.
In the mean time, a dermatologist appointment comes up; I need some suspicious dark spot checked out. After the whole body scan, she also asks: what's going on under that plaster on your shin, and can I have a look? She suggests I come in for a few sessions with a laser she has, Nd:YAG it says on the label and apparently it emits near infrared. They use it for cosmetic purposes, to promote collagen formation and what not, but she claims it will also do wound healing a lot of good. She offers the treatment for free, so how could I decline?
So they hammer the area on my shin with the pulsed laser. When it starts to get too hot to tolerate, they press a cooled tip against the skin to cool it down, then continue, until the pre-set dose is delivered. Next day I can see with my own untrained eyes a marked improvement. I go back for 2 more sessions over the next week or so. By the end of that, the skin has closed over and I can stop wearing waterproof dressings. This was borderline miraculous to me. Too bad about the scar/reminder....
So there are a few mechanisms that are proposed to work here: the heat increasing circulation, and/or causing slight damage which triggers increased healing mechanisms on, and/or the specific wavelengths stimulating the mitochondria to make them work better, etc.
Other comments have mentioned sunlight (especially early morning or late afternoon, when UV is low and long (red) wavelengths predominate). The wound care nurses have recommended sitting in the sun too, and I am sure that might also help somewhat, but in my case the laser worked much better.
Of course all the usual disclaimers apply like me not being a medical professional, no medical advice was given, or your mileage varying.