6 year old boy with LGS and ESES

My son is 6 years old with LGS and ESES.  His EEG is so active both awake and asleep.  In sleep he has continious spike waves from the minute he closes his eyes.  Awake it spikes between 2-5 sec's.  We have tried keppra, Banzel, and Zonegran.  He is currently taking Lamictol, Depakote, and is about 6 weeks into a 15mg. valium treatment at bedtime.  Over the past year we have seen some regression.  He was able to count to 20, and now we can barely get him to count to 5. 

Over the past 6 months we have seen some aggression.  He will hit, spit, scream, and bite.  My son has never done any of this before. My son will walk up to our infant and squeeze his arm or leg,  and he will pull the babys hair.  Sometimes he will be very gentle, but all of a sudden he will pull on the babys arm.  It is very scary, because he could harm our infant very bad. I never leave our son and our baby in the same room with out us watching.   Has anyone ever seen this type of behavior?  We have tried everything to redirect this behavior, and nothing seems to work.  Our neuro put him on risperidone, which made him hallucinate so we stopped it.  He then tried strattera, which made the aggression worse, so we stopped also.  We started tenex about 5 months ago, and is has not seemed to do anything.  We have taken him to a behavioralist, and got some neuro-physc testing done.  We also take him to a ped. psychiatrist.  Please any advice would help!

Concerned mommy