The brain and spinal cord together constitute the central nervous system (C.N.S.)

 Provides the structural and functional framework for thought, memory and emotion

 Permits us to reason, analyze etc.

 Processes sensory and motor functions

 The brain is a complex organ composed of different tissues including the electro-
   chemical connections (neurons) and supporting tissues, most of which are able to
   develop tumors

 Tumors rarely spread to other parts of the body

 They spread by local infiltration and may be extensive before functional changes occur

 Some are slow growing and push the normal surrounding brain tissue aside

 Neither benign nor malignant tumors have much room to expand

 The skull is a solid container completely filled by the normal brain and any growth may
    cause compression and pressure inside the head

 Primary brain tumors account for 3% of all neoplasms but is the most common solid
   tumor of children, accounting for 25% of all pediatric malignancies

 80% of brain tumors occur in adults between the ages of 50 and 60

  Brain tumors that occur in childhood often behave very differently from those that
    happen in adulthood.