what is meant by "lesions" in a neurological sense is not necessarily "holes"; when they talk about "vacuolation" (as with MDMA and methamphetamine neurotoxicity) they actually mean fluid-filled pockets inside neurons (these occur normally inside all cells, but would be abnormally large or numerous in a damaged cell). occasionally a lesion may be a large area of damaged, dead tissue, as would occur after trauma or stroke. olney's lesions -- well, olney's lesions (as i've said before) is a term from the 70's.
as if it hasn't been said enough, no, acid does not make your brain bleed. if you were to remove a portion of your skull and drop liquid acid directly onto the surface of your brain, it still wouldn't bleed. acid is chemically quite inert.
it's also tasteless. you should not expect hits to sting (which is another common myth). LSD (lysergic acid diethylamide, from the German, lysergesäure diaethylamid) is not actually even an acid; it's an amide, the condensation product of a (carboxylic) acid with an amine. and if it were an acid, even if it as strong as sulfuric acid, you probably wouldn't be able to taste quantities on the order of 100 micrograms.
LSD is a serotonergic agonist (or antagonist, or mixed agonist/antagonist; they're not entirely sure). it acts the same way ALL other (psychoactive) drugs do; it binds to receptors in the brain because it's similar to a chemical that already exists in the body. no bleeding.
oh, and it doesn't stay in your spinal fluids either. it's eliminated in the urine - like MDMA, like ketamine, like THC, like PCP, like heroin, like coke, like alcohol.