Brain Tumors, Part 1 — Introduction, Incidence, and Symptoms
What is a brain tumor?
A brain tumor is a growth of abnormal cells inside the brain. Most brain
tumors that children get are called primary brain tumors, meaning that
they are a tumor that originated in the brain and did not spread from
somewhere else. Tumors may be localized to a small area or may be invasive
(spread to nearby areas). They are also categorized as benign, which means
they are not cancerous, or malignant, which means they are cancerous.
Tumors may directly destroy brain cells or they can indirectly damage
brain cells by one of four other methods:
- by causing inflammation
- by compressing (squeezing) other parts of the brain as the
tumor grows
- by causing brain swelling, or cerebral edema
- by causing
increased intracranial pressure (the pressure inside the skull)
Brain tumors are classified by where they are in the brain, what kind
of tissue they are made up of, whether they are benign or malignant, and
other factors. There
are some types of cancer that tend to be hereditary, passing on from one generation
to another. Other types, like craniopharyngioma, seem
to be congenital, developing
before birth. Ultimately, the cause of most brain
tumors is not known.
Incidence and Prevalence
Brain tumors can occur at any age. Central nervous system tumors comprise
about 20% of all childhood cancers, second only to leukemias. The annual
incidence of brain tumors in children under the age of 15 years is about
3 per 100,000. More than 1,200 new cases of brain tumors occurs each year.
Many have a certain age group in which they are the most common. For example,
children tend to have astrocytoma, medulloblastoma, ependymoma, and brain
stem glioma. Gliomas account for 75% of brain tumors in children, but
only 45% in adults. Retinoblastoma is the only form of brain tumor that
is commonly seen in the first year of life
Symptoms
Specific symptoms and treatment is dependent on several factors, including
the site of the tumor, the type of tumor, and the age and health of the
person who has the tumor. Symptoms may include the following:
- Headache
- Vomiting
- Personality or behavior changes
- Emotional instability or rapid emotional changes
- Intellectual decline
- Seizures of new onset
- Facial paralysis
- Eye abnormalities, double vision
- Reduced level of consciousness or decreased alertness
- Weakness, lethargy
- General ill feeling or malaise
- Swallowing difficulty
- Impaired sense of smell
- Uncontrollable movement
- Hand tremor
- Confusion
In infants, additional symptoms may include
- Bulging fontanelles
- Separated sutures
- Failure to thrive
- Increasing head circumference
- No red reflex in the eye
Symptoms may change based on the status of the tumor. As swelling decreases
symptoms may decline; if the tumor size increases, symptoms may again present
in different ways. Change is common in the symptoms of a brain tumor.
Part 1 — Introduction, Incidence, and Symptoms
Part 2 — Treatment, Side effects and Restrictions
Part 3 — Implications for school
For more information, please contact:
Kathy Davis, MSEd, PhD
kdavis2@kumc.edu
(913) 588-6305