Gelastic seizures are difficult seizures to control and generally arise due to pathology in the temporal lobes or in case of hypothalamic hamartomas. I am sure your doctor has investigated the child. The combination of Lametec and sodium valproate is an excellent one. But if the fits are still not being controlled, one may have to consider using other medications like Levaterecetam or topiramate. You should discuss this with your neurologist - I am sure he would like to try other medications to control the seizures.