Thank you for your query.
may be present in some individuals without any cause be found for it. I am afraid anti-convulsant medicines will have to be continued for a long time. It shall be better to discuss with your doctor who may reduce the dose very gradually over a longer period of time. Some cases have known to be off medicines after continuing it for a longer period.
One has to weigh the benefit of giving the medicine than the side effects and in your child's case there is no other alternative.
I hope I have answered your query to your satisfaction.