Hello there, I can understand your concern for your son s worsening memory and cognitive functions. Now to answer your question the diabetic medicines are not known to directly cause any epilepsy. However when on insulin rarely the blood sugars may go so low that it may trigger a seizure. Because in an epileptic patient the trigger for low sugar will begin a seizure rather than the typical symptoms of low sugars like sweating, tremors, weakness, hunger its very difficult to know unless one check the blood sugar at the time the attack. Each time he gets a low sugar and he does not immediately take remedial measures (like eating some sugar or glucose biscuits) the brain suffers damage silently which may gradually lessen the threshold for further brain damage. In your son s case I can personally think of low sugars as one of the possible causes for his worsening memory and cognitive functions. Best way is to regularly keep checking his blood sugars at different times of the day, so that you are always aware of his control. His HbA1c (average blood sugars for 3 months) can be maintained somewhere around 8%. Fasting 120-130 and post meals 180-200. Do not try to achieve lower sugars. Do discuss these targets with your diabetologist who can adjust insulin doses accordingly. The epilepsy medicines are ok. Hope this helps. Take care.