A number of other neurological conditions that are not strictly found in the elderly are also being treated or partially managed with low carb diets:
ADHD
Autism spectrum disorders
Epilepsy
OCD
Multiple sclerosis

Interesting round-up on this from Dr. Ede: Ketogenic Diets for Psychiatric Disorders. I hate the title, because I think "psychiatric" implies something that can be improved with psychiatric therapy rather than a biological condition. There's a little blurring in the article of these two categories, as well, but it's still a good review.

Just checked on my holds at the library and Nutrition in Crisis has been added to my holds list! Also, I'm #1 on 4 copies, so they may have ordered it because I asked. They may have already been ordering it and I'm the first person to request it, but it wasn't in the catalog when I asked and it is now.