migraines and memory

My migraines are due to a head injury.  I was hit by a drunk driver 27 years ago.  I was in a coma for 10 days, had a stroke, concussion, hematoma, broken bones and pneumonia.  I don't have a connection to people who suffer migraines (and epilepsy) from a head injury.  One of the complications of these head injuries is memory.  I have limited memory before the accident and suffer from short term memory.  I make a lot of lists and them wonder what the lists are for.  Some days are much clearer than others.  The memory issues appear to be getting worse.  Is this just a natural effect of aging?  Can this be tied to the migraines or seizures?  I am currently 45.  Thank you!