The exact cause of brain tumors is yet unknown. Physicians, therefore, usually cannot explain why one person develops a brain tumor and another does not. However, research has shown that people with certain risk factors (e.g., family history, exposure to radiation or certain other chemicals, coexistence of a disease such as neurofibromatosis) are more likely than others to develop a brain tumor.
Brain tumor symptoms vary, depending on the tumor size, type and location. Symptoms may occur when a tumor damages a certain area of the brain or presses on a nerve. In addition, symptoms may be caused by tumor-related brain swelling or fluid buildup within the skull. The most common brain tumor symptoms include the following:
The above symptoms are not always indicative of a brain tumor, as they may be caused by other conditions. In fact, brain tumor symptoms often mimic the symptoms of other diseases, and vice versa. You should be evaluated by your physician if you are concerned about any of the symptoms listed above.
The brain contains three main structures: the cerebrum, cerebellum and brainstem.
The cerebrum is the largest area of the brain. It is divided into two halves referred to as the right and left hemispheres. The right hemisphere controls the left side of the body, and vice versa. Each hemisphere is composed of four sections-called lobes-as follows:
The cerebellum is the second largest part of the brain. It is located at the back of the head, between the cerebrum and the brainstem. The cerebellum is responsible for coordinating muscle groups for smooth and steady movements (e.g., balance for walking and standing) and controlling other complex motor functions.
The brainstem is located at the base of the brain and connects the cerebrum with the spinal cord. It provides the major route by which the upper portions of the brain send information to, and receive information from, the spinal cord and peripheral nerves. The brainstem is where the majority of the cranial nerves-including those that control hearing, vision, sense of smell and balance-are located. In addition, it contains conduction pathways going from the spinal cord to the brain that transmit messages related to movement and the senses. The brainstem also controls involuntary functions (e.g., breathing, heartbeat, sleep/wake cycle). The three main parts of the brainstem are the midbrain, pons and medulla oblongata. The midbrain is a short, narrow segment located toward the front of the brainstem and is involved with functions such as vision, hearing, eye movement, and voluntary motor function. The pons-which is Latin for bridge-"bridges" the portion of the central nervous system between the midbrain and medulla oblongata. It is in the pons that nerve cells cross from one side of the brain to control the opposite side of the body. The medulla oblongata is located at the lowest part of the brainstem. In addition to controlling essential life functions such as respiration, heart rate and blood flow, the medulla oblongata is also involved with sound localization (the listener's ability to identify the origin of a detected sound) and function control of coughing, sneezing, swallowing, blinking, vomiting and the sucking reflex.
Not all patients with brain tumors experience seizures, but some do. If you have never had a seizure, there is a good chance you never will. There are many different types of seizures. The type of seizure depends on the location of the brain tumor. Some of the more common types of seizures, which usually do not occur with loss of consciousness, include:
Patients who have experienced a seizure are put on anti-seizure (anti-epileptic) medication. Some of the more common medications used are Dilantin, Keppra, Depakote and Tegretol. Your physician will determine the most appropriate medication and dosage for you.
CT (computed tomography) scan uses an X-ray machine linked to a computer to take a series of detailed pictures of the head to reveal any tumors present in the brain. MRI (magnetic resonance imaging) uses magnetism, radio waves and a computer to produce detailed images of the brain. With both CT and MRI, the patient may receive an injection of a special dye to make abnormal brain tissue easier to identify in the pictures. Generally speaking, CT is used more frequently than MRI because it is more widely available, is less expensive and can be used on patients who cannot undergo MRI-including those with cardiac monitors or pacemakers, permanent surgical clips, or any metal fragments within their body-due to potential problems that may be caused by the magnetic fields. Compared to CT, however, MRI offers the following advantages:
Primary brain tumors arise in brain tissue, whereas metastatic, or secondary, brain tumors start as cancer cells in another part of the body and metastasize, or spread, to the brain through the blood stream. The most common types of tumors that spread to the brain are lung, breast, colon and kidney cancers, as well as malignant melanoma (skin cancer). Metastatic brain tumors are far more common than primary brain tumors. According to the American Brain Tumor Association, of the 190,000+ Americans diagnosed with a brain tumor each year, slightly more than 40,000 have primary tumors, while the remaining 150,000 have metastatic tumors.
Following a biopsy or tumor resection, a neuropathologist will examine a brain tumor under a microscope to determine the tumor grade, based on the cells' appearance. Cells from high-grade tumors look more abnormal and generally grow faster than cells from low-grade tumors. Brain tumors range from grade I (low-grade) to IV (high-grade). The tumor grade helps guide physicians in determining the optimal treatment for each patient (e.g., level and intensity of treatment required).
Brain tumors are cancerous in some cases, but not all. Malignant (high-grade) brain tumors contain cancer cells, but benign (low-grade) brain tumors do not. In very rare cases, some benign brain tumors later develop into cancer. Two of the most common forms of brain cancer are metastatic brain tumors (cancers that have spread to brain tissue from elsewhere in the body) and glioblastoma multiforme, or GBM (the most aggressive form of gliomas-primary brain tumors arising from glial cells in the brain).
Generally speaking, a benign tumor or condition is not harmful. However, that is not the case with anything growing in the brain, including benign tumors. There is a confined space within the skull, meaning it cannot expand to accommodate a growing tumor. Therefore, as they grow, benign brain tumors have the potential to become life threatening due to pressure on the brain. Fortunately, benign tumors generally grow slowly and rarely grow back after being surgically removed. Depending on the location and size of the tumor, however, benign brain tumors can sometimes be difficult to treat.
When a tumor is referred to as "stable," it means that the tumor cells are in a phase in which they have stopped growing or multiplying. Such stability may be temporary or permanent. When the tumor has actually been destroyed, and the area it occupied in the brain is composed only of dead tissue (necrosis), no new growth will occur. However, if tumor cells remain, it is possible that they will begin growing again at a later date.
Recurrent tumors are those that grow back after being surgically removed or stabilized. They can be either benign or malignant, although the latter is more common. Recurrent brain tumors often appear in the same area where the original tumor developed, but they may also develop in another part of the brain or spinal cord. It is impossible to predict whether or not a tumor will recur, and therefore, routine follow-ups (e.g., MRIs) are a necessity for all brain tumor patients.
Patients with benign and malignant brain tumors and long-term survivors often experience fatigue. Treatment-including surgery, radiation and chemotherapy-can add to fatigue, as can trauma to the brain due to the presence of a tumor, regardless of whether it has been surgically removed or not. To help manage fatigue, listen to what your body is telling you. If you are doing something and begin to feel tired, stop and rest. Taking naps will help give your brain and body the energy they need, both during and following treatment. It is much better to rest than to try to push yourself too hard. It is also a good idea to learn to identify the triggers that cause your fatigue. Being aware of your own limitations will allow you to better manage feelings of tiredness. It can be very frustrating for those who are unable to maintain the same level of activity as before they were diagnosed with a brain tumor. However, it is crucial that you allow yourself plenty of time to recover before you begin placing high expectations upon yourself. If you are experiencing fatigue, be sure to address your symptoms with members of your care team so they can provide you with available treatment options. In addition, it may help to talk with other brain tumor patients through support group meetings. It is likely they are dealing with fatigue and other symptoms similar to yours, and they may be able to help by offering coping strategies that have worked well for them.
It is difficult to summarize a single approach to coping, as each patient, family and brain tumor is different. Generally speaking, however, the brain tumor experience is a journey into scary and uncertain territory, from diagnosis through recovery. There is a lot to learn and cope with both physically and emotionally. It can be especially difficult for family members of a brain tumor patient, as they need to find the strength to be caring and supportive while also trying to manage their own fears. Researching brain tumors will help you and your family members become informed. The more information you know about your condition and the more you understand about each aspect of your treatment, the less uncertainty there will be. Making an effort to maintain as positive an outlook as possible toward your condition and treatment can be very important. Having hope and believing in the power of healing can help empower you and your loved ones to look past the present and into the future.