What is Raymonds health condition in "Raymond's Run" by Toni Cade Bambara?

In Toni Cade Bambara's short story, "Raymond's Run", the narrator's brother, Raymond, has a health condition called hydrocephalus. This condition is marked by too much fluid on the brain causing it to swell. Those that suffer from hydrocephalus are often mentally handicapped like Raymond is in this story. We know that because even though Raymond is older than Squeaky, she has to take care of him and to make sure he doesn't get into any mischief like a much younger boy might get into. Even though Raymond is handicapped, by the end of the story we find out that due to all of Squeaky's training and the fact that Raymond has had to keep up with her, he has become quite a good runner himself!