“..Roberts takes Dilantin, a seizure medicine ....”
How do you know this?
It was public several years ago.
I didn't look further but if he was diagnosed with epileptic seizures then he was given Dilantin and probably barbituates. Once on these medicines no doctor will go along with getting off of them, at least for us common folk due to liability concerns. The cause can be nerve breakage which does heal if the break is not too wide but very slowly. Mine did but getting trapped at sea for 6 weeks with a two week supply of meds is what got me off because I went 4 weeks with no seizure and have not had one since. And my perceptions and ability to resist pressure etc has all(slowly) returned to pre seizure normal.