I got really upset about something, a little while ago, so I strangled myself for up to three seconds... I stopped when I came to think about brain damage. I've heard that strangulation can lead to build-up of waste material in the brain, which will lead to brain damage (and dementia, later in life, if you live a longer life). I have a very strange headache, in various places of my head, now, so I was wondering if anyone knows how long it takes for waste material to have time to build up? How long does the strangulation have to take place for brain damage to occur, as well?