It’s definitely happened. I think the technical term is “vertebral artery dissection.” I don’t think it’s like a daily occurrence or anything, but there is a very real risk of it happening whenever you get a chiropractic adjustment on your neck. Basically you have some delicate arteries running through your neck bones and the sharp sudden movement of certain chiropractic adjustments have the potential to rupture them. It can cause a stroke and some various other bad things that can happen when blood flow through the spine is interrupted.