My expert neurologist performed 2 EEGs and MRI which were normal and discontinued 500mg Keppra. Two weeks later, major seizure. Is this common?

Some basics. A person can have a seizure disorder with normal EEG's & MRI's and also have no seizures with abnormal studies. It is common for any doc to consider stopping a long term seizure med if a person has been seizure free for several years. I would usually wean it over a week or more. Removal of any seizure medication can allow a hidden issue to re-emerge. Such would suggest lifelong continuation needed.
Seizure disorder. with recurrence adter discontinuation suggests need for prphylactic therapy. .