A brain tumor is massive growth of abnormal cells in the brain or close to the brain. There are many different types of brain tumors and they are often graded on a scale of 1 to 4 according to their growth rate and the likeliness that they will reoccur after treatment.
- Non-cancerous (benign) tumors are low grade (1 and 2), which means they grow slowing and are not likely to reoccur after treatment.
- Cancerous (malignant) tumors are high grade (3 and 4) and can start in the brain and spread to the brain from other areas. They are likely to grow back after treatment.
Primary brain tumors emerge from various brain cells and the central nervous system. The most common types of adult brain tumors are:
- Gliomas tumors and Astrocytic tumors
The second most common type of adult brain tumors are:
- Meningeal tumors: tumors that form in the meninges, the thin layer of tissue that covers the brain and spinal cord.
The growth rate as well as location of a brain tumor determines how it will affect the function of the nervous system.
The signs and symptoms of a brain tumor vary greatly, depending on the brain tumor's size, location and growth rate. Symptoms caused by brain tumors may include the following:
- Severe, throbbing headaches
- Persistent nausea and vomiting
- Abnormalities in vision
- Intellectual or emotional changes
- Speech impairment
- Clumsiness, weakness or paralysis on one side of the body, arm or leg.
- Seizures (fits)
- Hearing problems
As with tumors elsewhere in the body, the exact cause of most brain tumors is unknown. There have been however, factors that propose risk increase of a brain tumor.
There are some factors that may cause risk increase of a brain tumor. These risk factors include:
- Age: Brain tumors are most common in older adults; however, they may occur at any age.
- Radiation exposure: Examples such as radiation therapy used to treat cancer or radiation exposure caused by atomic bombs.
- Family history of brain tumors: Genetic syndromes may increase the risk of brain tumors.