Brain tumors are the most common solid tumors in children. Approximately 3,800 children and adolescents under age 20 in the US are diagnosed with primary brain tumors each year. Primary brain tumors start in the brain and generally do not spread outside the brain tissue. Brain tumors, either malignant or benign, are tumors that originate in the cells of the brain. A tumor is an abnormal growth of tissue.

A benign tumor does not contain cancer cells and usually, once removed, does not recur. Most benign brain tumors have clear borders, meaning they do not invade surrounding tissue. These tumors can, however, cause symptoms similar to cancerous tumors because of their size and location in the brain.

Malignant brain tumors contain cancer cells. Malignant brain tumors are usually fast growing and invade surrounding tissue. Malignant brain tumors very rarely spread to other areas of the body, but may recur after treatment. Sometimes, brain tumors that are not cancer are called malignant because of their size and location, and the damage they can do to vital functions of the brain.

Brain tumors can occur at any age. Brain tumors that occur in infants and children are very different from adult brain tumors, both in terms of the type of cells and the responsiveness to treatment.

Anatomy of the brain :

The central nervous system (CNS) consists of the brain and spinal cord. The brain is an important organ that controls thought, memory, emotion, touch, motor skills, vision, respirations, temperature, hunger, and every process that regulates our body.

The brain can be divided into the cerebrum, the brainstem, and the cerebellum:

  • cerebrum (front of brain) – composed of the right and left hemispheres. Functions of the cerebrum include: initiation of movement, temperature sensation, touch, vision, hearing, judgment, reasoning, problem solving, emotions, and learning.
  • brainstem (base of brain) – includes the midbrain, the pons, and the medulla. Functions of this area include: movement of the eyes and mouth, relaying sensory messages (i.e., hot, pain, loud), hunger, respirations, consciousness, cardiac function, body temperature, involuntary muscle movements, sneezing, coughing, vomiting, and swallowing.
  • cerebellum (back of brain) – located at the back of the head, its function is to coordinate voluntary muscle movements and to maintain posture, balance, and equilibrium.

 

What causes brain tumors?

The majority of brain tumors have abnormalities of genes involved in cell cycle control, causing uncontrolled cell growth. These abnormalities are caused by alterations directly in the genes, or by chromosome rearrangements which change the function of a gene.

Patients with certain genetic conditions (i.e. neurofibromatosis, von Hippel-Lindau disease, Li-Fraumeni syndrome, and retinoblastoma) also have an increased risk to develop tumors of the central nervous system. There have also been some reports of children in the same family developing brain tumors who do not have any of these genetic syndromes.

Research has been investigating parents of children with brain tumors and their past exposure to certain chemicals. Some chemicals may change the structure of a gene that protects the body from diseases and cancer. Workers in oil refining, rubber manufacturing, and chemists have a higher incidence of certain types of tumors. Which, if any, chemical toxin is related to this increase in tumors is unknown.

Children who have received radiation therapy to the head as part of prior treatment for other malignancies are also at an increased risk for new brain tumors.

What are the symptoms of a brain tumor?

The following are the most common symptoms of a brain tumor. However, each child may experience symptoms differently. Symptoms vary depending on size and location of tumor. Many symptoms are related to an increase in pressure in or around the brain. There is no spare space in the skull for anything except the delicate tissues of the brain and its fluid.

Any tumor, extra tissue, or fluid can cause pressure on the brain and result in the following symptoms:

increased intracranial pressure (ICP) – caused by extra tissue or fluid in the brain. Pressure may increase because one or more of the ventricles that drain cerebrospinal fluid (CSF, the fluid that surrounds the brain and spinal cord) has been blocked, causing the fluid to be trapped in the brain. Increased ICP can cause the following:

  • headache
  • vomiting (usually in the morning)
  • nausea
  • personality changes
  • irritability
  • drowsiness
  • depression
  • decreased cardiac and respiratory function and eventually coma if not treated

 

Symptoms of brain tumors in the cerebrum (front of brain) may include:

  • seizures
  • visual changes
  • slurred speech
  • paralysis or weakness on half of the body or face
  • increased intracranial pressure (ICP)
  • drowsiness and/or confusion
  • personality changes/impaired judgment
  • short-term memory loss
  • gait disturbances
  • communication problems

 

Symptoms of brain tumors in the brainstem (base of brain) may include:

  • seizures
  • endocrine problems (diabetes and/or hormone regulation)
  • visual changes or double vision
  • headaches
  • paralysis of nerves/muscles of the face, or half of the body
  • respiratory changes
  • increased intracranial pressure (ICP)
  • clumsy, uncoordinated walk
  • hearing loss
  • personality changes

 

Symptoms of brain tumors in the cerebellum (back of brain) may include:

  • increased intracranial pressure (ICP)
  • vomiting (usually occurs in the morning without nausea)
  • headache
  • uncoordinated muscle movements
  • problems walking (ataxia)

The symptoms of a brain tumor may resemble other conditions or medical problems. Always consult your child’s physician for a diagnosis.