Chronic daily headache - transformed headache

My 81 year old mother has always had headaches.  Sinus surgery years ago didn't solve the problem.  She was on Fioricet for quite some time and was taken off that with phenobarb (temp dosage) and depakote to stop the rebound headaches.  The depakote actually seemed to work for awhile, but she began to have headaches again.  She used tramadol for some relief.  The use of tramadol increased.  She was just started on a cycle to move her to topamax and off depakote.  It has been 3 full days of 500 mg of depakote twice a day and 25 mg of topamax in the evening.  She has had a severe headache now for 2 days.  Perhaps topamax is the cause?  Her headaches are not migraines.