Congenital Hydrocephalus

Does anyone know anything about this condition?
Have you had a pup with this?
How noticable was it ?
In your opinion Is it a condition you would think could go un-noticed?
Have you known a pup to develop it at later stages ie juvenile hydrocephalus?
I'm eager to gain as much information as I can.
If anyone can help plese feel free to message me or e-mail if you don't want to post an answer on the forum.
Please help if you can
Thanks