I have incidents where i briefly lose my ability to read-i have both seizures and migraines- which is the likely culprit?

Seizure activity: Although the migraine, if complex with aura, could cause visual obscuration, and brief confusion, more likely you are experiencing more frequent focal or partial seizures than you realize and this results in compromise of your cognitive abilities. Recommend a sleep deprived eeg and adjustment or modification of your anti-epileptic drugs. Might benefit from a few visits to speech therapy also.

Either: I would lean toward the seizures. In either case you need to go see a neurologist. Loss of the ability to read is a serious complaint and needs to be evaluated.