In general nerve cells within the brain are unable to duplicate and grow, which means that most brain tumors do not arise from cells. However, there are other tissues in the brain that serve the nerve cells, and these cells can form tumors. Pediatric brain tumors are not always cancerous but are always dangerous because they can interfere with brain function.
Medulloblastoma
Medulloblastomas, according to the Pediatric Brain Tumor Foundation, typically begin in the cerebellum, which helps control voluntary movements. Children with a medulloblastoma can have trouble sleeping, experience double vision (from problems moving the eyes) and can suffer from headaches, vomiting and irritability. Medulloblastomas can also make handwriting difficult and can cause problems with balance and coordination. If the tumor affects the spinal cord, it can also lead to back pain and problems with controlling the bowels and the bladder.
Glioma
Gliomas are tumors of the glial cells, which work to support and protect the nerves in the brain. Gliomas can cause different symptoms depending on their location. If they occur in the cerebellum, they can cause symptoms similar to those of a medulloblastoma. Gliomas can also cause partial paralysis (either of one body part or one side of the body) as well as tremors, hormone imbalances and diabetes inspidus. In very young children they can also cause hydrocephalus, which causes the skull to become larger and also results in vomiting, seizures and visual problems. According to the Pediatric Brain Tumor Foundation, one special kind of glioma is called an ependymoma. This type of brain tumor causes hydrocephalus as well.
Astrocytoma
Astrocytomas frequently are not cancerous but they are still dangerous. If they are formed in the cerebellum, they can cause poor balance, lack of coordination and decreased muscular tone throughout the body. If they occur in the cerebrum they can lead to hallucinations, seizures, weakness of the muscles in the limbs, as well as headaches and vomiting. If the astrocytoma is in the brain stem it can cause problems with the pituitary, leading to early or delayed puberty as well as unusually short stature with growth problems. Astrocytomas can also cause hydrocephalus, leading to a buildup of fluid in the head which can cause headaches or an increase in skull size.
