The first time I remember hearing of the trick of using IR for deep tissue healing it was being investigated for healing the Bends in Navy Divers at the University of Wisconsin in 2000.
http://healthlink.mcw.edu/article/975450257.htmlThe theory then was that the IR was being picked up in the cytochrome in each mitochondria and thereby providing a direct power feed to each cell.
IR light forced more ATP generation at the mitochondrial level.
How the Hell Does this Work???
Well....
This was thought to bypass failing transport mechanisms (like the blood stream) to get past the circulatory damage that the Bends caused in divers.
I could see how this same 'trick' could bypass part of the failing circulation and neuron/neuron transport that might contribute to the body not being able to heal Alzheimer's Disease.
ATP is the general power currency off the bioworld, so this is the equivalent of broadcast power for each cell.
Tesla would be proud!
Disclaimer: I'm not a doctor, I'm a mad scientist.
(OK OK, I'm a biology student/researcher at the University of Kansas.)