Truthfully it is very possible to have a stroke r/t a neck dissection, since the location of a dissection is close to the carotids, its very possible that scar tissue, clips or anything like that could cause a minimization or loss of blood flow to the brain, it could cause plaque to break off and move, there are numerous things that can happen. The intracranial hypertension also has a similarbcause, swelling and pressure related to build up of fluids, caused by scar tissue, compromised pathways, hypertension for the same reasons. Unfortunately you need to see a neurologist to determine the cause of both. Best of luck.