http://www.hopkinsmedicine.org/neurology_neurosurgery/centers_clinics/brain_tumor/treatment/surgery/post-surgery-care.html
The brain is part of the nervous system which is the system being affected by this surgery. Your brain sends messages to the rest of your body about different things happening in and around you.
This surgery affects the brain. The brain is the computer of the body. It controls everything that is going on inside.
The neurons in the brain are being killed off by this tumor and when they begin to die they don't come back which causes the brain to die if not treated right away.
This surgery can depend on lots of things: the type of tumor, the size of tumor, patients age, etc. The recovery time is usually 2-5 days in the hospital and then having to rest for a few more weeks at home. The patient will need a lot of rest to get their brain power back and moving of the head is is not healthy. There is no medication. Most people get their heads shaved previous to the surgery for easier access.
Brain surgery is very extreme and doctors have to let their patients know the risks that come with the surgery. If someone makes a wrong move, they could "turn off" a part of the brain.