I can recommend a lot of supplements for brain but most would harm if there is existent damage.

Eat a lot of nuts walnuts specifically, high hanging fruit and nuts. Pickup immune boosters like mushroom supplement drops, chia seed, black seed oil and fish oil maybe B vitamins. (All available at GNC and Vitamin Shoppe)

Also look into a doing a thorough detox and eat raw as mush as possible until you feel treatment is complete

"Let food be thy medicine, let medicine be thy food."
Hypocrates