Any kind of parasites can get into your brain, no problem. Your blood/lymph will take them anywhere they wish. You need to be careful if you do a protocol that targets them. It is really the best to get tested beforehand with elisa, it is far more reliable than any other tests. Today read that it can still distort results if you are infected with more than one type and so repeating testing is a good idea.
Mattk3 has experience as well as others here.