A diagnosis of cancer is always difficult and very frightening. You should feel free to discuss all of your questions and concerns with your oncologist
, since he or she will be the person guiding you through your cancer care.
To answer your specific question, there are different kinds of brain tumors and they can affect people in different ways. They are often treated differently, as well. First, there are brain tumors that are so-called primary brain cancers, i.e. the tumor started in the brain. Any part of the brain--the cerebrum that controls our movement and cognitive function; the cerebellum that controls movement and balance; the meninges or layers of protective lining around the brain--can develop a tumor. The symptoms a person may develop often depend on the part of the brain where the tumor starts. For example, if the tumor is predominantly in the frontal part of the brain that controls inhibitions, the person may start staying things that seem abruptly uncensored.
However, some brain tumors are referred to as metastatic tumors, i.e. the primary tumor started somewhere else (the lungs, the breast, the kidneys) and then spread to the brain. In many cases metastatic disease will spread to more than one area of the brain at the same time which can then cause more diffuse or widespread symptoms. Please talk to your oncologist for more information. Good luck.