While the toxicity of Toluene is well documented, researchers are limited into looking into the actual mechanisms. As such, the precise mechanisms are currently not known. Basically, science has to look at the effects of those unfortunate enough to be exposed to toxic levels. The "how it does that" question is not so important as the "what it does" (quite a lot of bad things, getting worse and worse with more exposure) and "can we do anything about that?" (No, - supportive measures only)
What we do know is that it is an industrial organic solvent, As everyone gets waned in Orchanic Chemistry laboratory 101 - that usually means is will go right through YOU - you are organic chemistry embodies. (always wear your protective equipment). Such solvents tend to go right through the skin and distribute throughout your body. As such, it is believed that it damages every organ to one degree or another. As a solvent, it goes right through the blood brain barrier. And your brain being the organ most vulnerable to even small scale disruptions, it shouldn't be surprising its effects show up there most.
The current theory "CNS toxicity may be due to the liposolubility of toluene in the neuronal membrane. It has been suggested that toluene interferes with the normal function of neuronal proteins." - (site https://www.atsdr.cdc.gov/mmg/mmg.asp?id=157&tid=29) So say your brain is nice greasy dish with some water in it - and is supposed to be that way. Tolune is like putting some Dawn dish detergent in it.
But it bears mentioning Tolune is broken down into a goodly number of metabolites, any one of which may be the true culprit for damage to other organs.
In any case, encourage anyone you know to stay the heck away from it and take precautions like gloves when handling it. There is no antidote or treatment, and given it's chemical nature I highly doubt there ever will be.