I have epilepsy and Im trying the ketogenic diet, together with the Paleo. Im an adult and its helped me enormously. The difference between the ketogenic and the paleo is that the Ketogenic diet is a lot stricter and needs careful monitoring. Its stricter in the sense of much lower carbs and keeping a diary of them on a daily basis. Its quite a faff but to me its worth it!!
I have to keep my carbs at 10 to 15, when others can have more - some even less to almost none.
There are quite a few books on ketogenic diets and though, as you say, they are geared more towards children, the principle is the same as it is for adults.
I think America is a lot better than they are over here in the UK where there is one 1 ketogenic clinic for Adults, but if he is going to take that route, he will need careful monitoring initially. Any 'cheats' can have detrimental effects and bring on a seizure so you need to be very strict with yourself.
I'm not a complete idiot! There's parts missing!!