Susan,
Get in touch with the Hydrocephalus Association:
http://www.hydroassoc.org/default.htm
For personal, one-to-one support, call our office directly: 415-732-7040 or toll-free 888-598-3789. Tell them you need HELP.
Call one of the neurosurgeons listed in the Hydrocephalus Association registry and BEG/CRY (use your "Hysterical Mother" voice) for them to come in on a consult for your son:
http://216.82.69.211/Pediatric.asp
These programmable shunts fail -- they fail sometimes as soon as they're installed.
A total 360 degree change in behaviour in a child indicates that that change in behaviour is probably caused by whatever is different in his life -->> that is the shunt.
I'm sorry this is so hard for you, Susan. Liz (AKA "my favorite Lizard") is right, if you can find a male to come with you and your child to the doctor (husband, Rabbi, Priest, friend), it helps.
Stay in touch. Let us know how it goes. BIG HUGS (and praying for relief for Nick).
Barb