Here is a video story of a man with a possible diagnosis of Parkinson's, who decided to be tested for CCSVI. He was shown to have jugular valve irregularities, and was treated with venoplasty. CCSVI exists. It is a venous disease, which has neurological consequences (that may lead to a diagnosis of MS, Parkinson's, dementia.) The brain needs adequate venous drainage for blood, CSF and lymph.

Here's a case treated by CCSVI balloon angioplasty , but not MS.