Has your brother ever tried a chiropractor? Just as JoMar stated, and a good physical therapist. Sometimes therapy is all you need.

Sounds like he has some nerves being pinched around L4-L5. Hence right leg issues. Even the facial issues sounds like it is nerve related.

Good conservative treatment is the best first line of defense. Unless your doc thinks he needs to see a neurosurgeon.

I will pray for your brother that he finds the relief that he needs. I've been there. But, our bodies, are all different. He is young and if they can help now, he will fair better as he ages.

Let us know how he is doing.
God Bless