It's good to know that your brother is ok... .
It is really nice of you that you are wanting to help your brother and be there for him.
i want to open a window if communication with my brother and talk to him about my mom and try to get him to understand what issues she may have but im afraid to sound pushy and intrusive.
How about asking him some questions first to see what he thinks and see it as a first of several talks with him? You might be able to see what might be appropriate to say at the first time so it's not overwhelming.