I've googled this and I know it has to do with heavy dissociative use such as PCP, Ketamine, and Dextromethorphan. I also know it's holes in the brain, but I want to know how likely are they and recorded cases of them from Dextromethorphan use. I'll continue to research on my own but I was wondering if anyone had anymore information on them just lying around.Also I don't want information on Cordicdin since that has several other active ingrediants which are more deadly then the Dextromethorphan its self.