Brain stem glioma accounts for about 10 to 20 percent of childhood central nervous system tumors. Gliomas are tumors that start in brain cells called astrocytes. Astrocytes nourish neurons and form scar tissue when the brain is damaged. Brain stem gliomas tend to occur in children between ages 5 and 10.
Brain stem gliomas occur in the brain stem, which connects the brain to the spinal cord. The brain stem is located in the lowest part of the brain above the back of the neck. It consists of the midbrain, which develops from the middle section of the embryonic brain; the medulla, located deep in the posterior part of the brain; and the pons, which is between the medulla and the midbrain. Most brain stem tumors develop in the pons and have a poor prognosis.
