What Causes Sudden Disorientation Inspite Of Xanax Intake?

My wife will at times blank out then utter something like "allright!" then "I'm okay". This is followed by a moment of disorientation. She will ask what day it is then seems to level out . I will at that time give her a 1/2 tab of Xanax (prescribed) which in time seems to help. She wonders if she may have had a seizure. I wonder if she may have experienced a panic attack. Please advise.