Hi, I am a new user so hopefully this goes well.
I have been to a few psych wards and none of them were a pleasant experience.
In your brothers case I don't find any reason for them to be not attending to his needs. And not having anyone around to help him seems like a problem. I don't find this normal at all. When I was apart of a mental hospital I always had doctors and nurses checking up on me, and they weren't terrible at they're job either.
With the sleep deprivation, I do find it hard to sleep while there. In my case I was checked up on every 15 minutes and that including in the night. There was a window in my door and they would shine a flashlight in until they could see that I was breathing.... every 15 minutes. It was pure torture. Also the walls were super thin so you could hear every single patient who was having a hard time sleeping.
There isn't much you can do. Maybe try talking to doctors to help him feel more wanted? Not sure how that would go but it is worth a try.
I'm sorry you're going through this, it sucks.