Migraine Headaches

My son is 21 years old and has suffered with migraines since age 5 he is now having a fogginess and some tingling in his arms and legs and loss of vision to the sides, is this something that other people have experienced, he was on amytriptyline for years and it helped a great deal but eventually his body processed the medication to quickly (or something like that) so we took him off the medication.  He has had MRI's and EEG's done and no one has ever found any problems with his brain.  Please help.

[Manhattan]

i know i've read you can have symptoms like that with headaches. my headache specialist said that topamax worked very well to prevent migraines, if you want to try something new. the clean mri is a very good sign.