there’s a ton of info out there that seizures are due to magnesium deficiency. look it up and get on mag malate and glycinate (total of 800 mg/day spread through the day) and get the mag oil that you spray on and rub in.
I hate to say what I think it is.
Excellent advice. Most people are magnesium deficient and it can and does create many different issues. Hope your BIL gets answers soon.