does a tap on the head, cause water on the brain ?

Answer 1

YuP!!! Your a genius!!!

Answer 2

Well not a tap usually, but one of the ways hydrocephalus (water on the brain) can occur is by traumatic head injury. Other ways are "complications of premature birth such as intraventricular hemorrhage, diseases such as meningitis, tumors..." "...or subarachnoid hemorrhage blocking the exit from the ventricles to the cisterns and eliminating the cisterns themselves."

You can read more about it at:

http://www.ninds.nih.gov/disorders/hydrocephalus/detail_hydrocephalus.htm#83433125

and

http://en.wikipedia.org/wiki/Hydrocephalus

Answer 3

no. water in the brain(hydrocephalos) is caused by the over production of csf(cerebro-spinal fluid) and a mild tap on the head doesn't trigger the excessive production of csf.