I think you should discuss this with your doctor.

There is a link some believe to migraine with stroke.

Also blood pressure changes may provoke strange feelings/perceptions.

Do you have a blood pressure cuff? Taking your pressures and logging them in a journal may show something, that you can then discuss with your doctor.

People with very low magnesium levels, often have blood vessel spasms. Magnesium has been used in migraine prevention as well.
This subject has just exploded in the past few years. There are two well known doctors who have written books on it.
I have a magnesium thread on vitamin forum:
http://neurotalk.psychcentral.com/thread1138.html
This thread helps you choose a supplement that is safe and really works (not all do).

If you Google migraine magnesium you will find many sites today like this one:
http://www.thedailyheadache.com/2007...ium_migra.html
(the statement on that tho about magnesium oxide being bioavailable has been shown to be questionable however. Other forms are generally more absorbed).

Some magnesium daily (I use almonds most of the time myself) willl help with leg cramps too.