I really don't know if the combination of a short acting or low dose MAOI and MDMA would be *more* neurotoxic than taking the two separately. I was under the impression that (1) MDMA is believed by many to be neurotoxic, and (2) combining it with an MAOI puts you at risk for hypertensive crisis.
MAOI's block the metabolism of norepinephrine, serotonin, and dopamine in the brain. Tyramine is normally (for someone not on an MAOI) deactivated in the g.i. tract and liver so large amounts of it don't get circulated, but since this deactivation is blocked by MAOI's, the tyramine gets absorbed and causes a sudden HUUUUGE release of norepinephrine (which I'm guessing is why you got sooooo fucked up. well, that along with the whole basic serotonin blow up thing going on from the roll ). Hypertensive crisis *may* result, but if you luck out and it DOESN'T, I don't necesarily think that you would end up more brain-mashed from the experience.
I always thought that it was the possibility of the whole hypertensive crisis/ hyperthermia/ heart attack/ intercranial bleeding that was the main concern...