Brain tumors can be classified in two ways. Primary brain tumors originate in the brain or the spinal canal, whereas secondary tumors spread from other areas of the body to the brain or the spinal canal. Approximately 25 percent of brain tumors are secondary, and all secondary brain tumors are malignant. The majority of secondary brain tumors are caused by lung cancer that has metastasized.
Primary brain tumors, however, may be benign or malignant. They develop from different types of brain tissue, and are often named after the areas in which they originate. Primary benign tumors usually grow very slowly; primary malignant tumors usually grow rapidly and are life-threatening. Although a primary malignant brain tumor is sometimes referred to as a “brain cancer,” unlike most types of cancer, it rarely spreads to other parts of the body. It can, however, spread within the brain and spinal cord.
Risk Factors for Primary Brain Cancer
The specific cause of primary brain cancer, and why it develops in some people rather than others, is unknown. It is believed, however, that certain factors may increase the risk of developing it. Some of these risk factors include:
- Family history of brain cancer
- Cigarette smoking
- Exposure to ionizing radiation
- HIV infection
- Exposure to environmental toxins
Ionizing radiation is produced by cancer-treating radiotherapy and atomic bombs. There is no proven link between brain cancer and radiation from microwaves or cell phones.
Symptoms of Brain Tumors
- The symptoms of both a benign and malignant brain tumor are usually caused by the swelling and inflammation caused by the growing tumor, and by its pressing on other parts of the brain, which prevents the brain from functioning as it should. However, brain tumors may also be asymptomatic. Common symptoms of both benign and malignant brain tumors include:
- Difficulty walking
Because they tend to have defined margins, and be rooted less deeply than malignant brain tumors, benign brain tumors are easier to remove surgically.
Hydrocephalus is the build up of excess fluid within the brain. Often caused by an obstruction in the brain that prevents proper fluid drainage, the ventricles of the brain may enlarge to accommodate the extra fluid, and put pressure on different parts of the brain, causing many troubling symptoms. This condition is usually present at birth, although it may develop later in life as a result of lesions or tumors within the brain, central nervous system infections or severe head injuries.
Causes of Hydrocephalus
Congenital hydrocephalus is present at birth and may be caused by genetic abnormalities or developmental disorders. Babies born prematurely with severe bleeding within the ventricles of the brain are also likely to develop hydrocephalus. Acquired hydrocephalus, can affect people of any age and it may be caused by bleeding in the brain from a stroke or head injury, brain tumors, infections such as bacterial meningitis, or traumatic head injury. Some older adults over the age of 60 may develop hydrocephalus, as excessive fluid builds up slowly from poor drainage, and the enlarged ventricles gradually press on the brain and cause symptoms.
Diagnosis of Hydrocephalus
In infants, hydrocephalus can often be diagnosed during a normal prenatal ultrasound. After the baby is born, hydrocephalus may be suspected if the child has an abnormally large head. In older children and adults, hydrocephalus is diagnosed through a physical examination and neurological evaluation. Additional diagnostic imaging tests of the brain may include a CT or MRI scan. Tests to measure and monitor brain pressure may also be performed.
Treatment of Hydrocephalus
Treatment for hydrocephalus usually involves surgery to restore proper fluid drainage within the brain. There are two procedures commonly used to treat hydrocephalus.