Whispering, not present, disengaged

My 10 yr old son was recently diagnosed with a seizure disorder. It took a year and a new neurologist to figure out what was going on. He was experiencing absence seizures. It started out as teachers thinking that he was "checking out" when school got boring. As time went on my son was "checked out" for about 95% of the day. Our former neurologist said he had serious mental health issues and dismissed us. At that time he was whispering/talking to himslef in partial words and phrases that weren't connected to what was going on and didn't have any flow to them. ie - wasn't just scripting from Lion King or other Disney movie innhis head. It was like neurological mish mash. He was not accessible at school or at home. It was like he disappeared. After findng the right AED and the right dosage he started to "come back" and he was able to engage with others again. I have done a lot of reading and have not come up with anything like this as a symptom of seizures. Has anyone else expeienced this level of disengagment? This went on for about 8 months before things started to get better. We have increased and added another med as things seem to be ok for awhile and then the whispering and disengagement creeps back in. Any informatin would be helpful. Thanks:)