Hi, Samantha--welcome to the community! You found a good place to find information as well as make friends!
We have a special forum for Arnold Chiari, and also one for Hydrocephalus. If you haven't found them on your own yet, here they are:
http://neurotalk.psychcentral.com/forum71.html
http://neurotalk.psychcentral.com/forum14.html
We also have forums where you can just relax and chit-chat. Jump in anywhere!