Definition and causes of Brain Tumors

Tumors in the brain can be benign or malignant. A brain tumor can be primary, meaning that it arises directly from tissue in the brain, or it may be secondary, which means that it is a metastasis which has spread via the bloodstream from a malignant tumor somewhere else in the body typically from the lungs or the breast.

Malignant tumors (cancers) spread by growing invasively into the surrounding tissue. Benign tumors do not destroy other tissues, but can still grow larger in a defined place. Since the brain is located inside the skull, which is a rigid box, even benign brain tumors can cause serious symptoms as a result of pressure on the brain. It may be very difficult to remove a brain tumor without damaging the healthy brain tissue.

Both adults and children can have brain tumors. In children malignant brain tumor is the second most common cancer with approximately 1 new case annually for every roughly 120.000 citizens in western countries. Children often have symptoms quite early during the illness. Tumors may occur in all types of cells in the brain, neurons, support cells, (particularly astrocytter), from the meningeal membranes surrounding the brain and the brain arteries. The symptoms vary depending on where the tumor is located and which part of the nervous system is affected.

Symptoms of brain tumors

Children:

The early symptoms are often vague such as poor well-being, irritability and vomiting (especially in the morning). There might be motoric trouble, which means that the child has difficulty controlling movements. If the tumor blocks the normal drainage of Cerebrospinal Fluid there is hydrocephalus which is an excessive build-up of fluid within the skull. In children under eighteen months this condition might result in an enlarged head as in these very young children the cranial bone parts have not yet grown together.

Adults:

The most common symptoms are:

• Headache, particularly in the morning, by coughing, exertion or position change.
• Fatigue.
• Cognitive impairment, which means having trouble remembering and concentrating. Indeed there may be a true dementia status.
• Epilepsy.
• Visual disturbances.

In addition, the location of the tumor will result specific symptoms connected with impairment of that particular part of the brain. It may, for example be sensory disturbances or force reduction in an arm, change of personality, localized seizures and speech impairment possibly as aphasia. There may be visual, hearing, smell, and taste hallucinations.

Precautions and diagnosis

Any of these symptoms require immediate medical attention and referral to neurologist or neuro-surgeon for full examination. Where there is suspicion of a brain tumor the examination will include a CT or MRI scan of the brain, possibly with X-ray contrast.

Treatment of brain tumors

Acute:

When there are symptoms of elevated pressure within the skull and the risk for life-threatening herniering, attempts are made to reduce the pressure by giving adrenal cortical hormones in large doses. This, however, takes approx. 6 hours to take effect, so if there is an urgent need for results also mannitol, a sugar substance, is given which can extract water from the brain with pressure reduction as the result. It might be relevant to place the patient in a respiratory and hyperventilate which also help reduce the pressure in the brain.

Tumor treatment:

• Operation: An operation is performed either to remove the tumor completely, if possible, or to reduce the size and hence the symptoms. Whether the entire tumor can be removed or not depends on how large the tumor is and where it sits. When the entire tumor or parts of it is removed, it will be sent to a pathologist for examination of the type of tumor involved. If the tumor blocks the normal drainage of Cerebrospinal Fluid and it cannot be removed a drain might be inserted to reduce the pressure on the brain.
   
• Radiotherapy: Irradiation of a tumor reduces the size of the tumor, thereby relieving symptoms. Radiotherapy is used either alone (if no surgery) or after surgery, if it has been impossible to remove the entire tumor.
   
• Chemotherapy: The different kinds of chemotherapy are often not very effective against brain tumors because they can not pass from the bloodstream into the brain tissue (blood-brain barrier). Some tumors are nevertheless sensitive to chemotherapy, and often chemotherapy will be combined with radiotherapy.
   

Outlook and complications

A brain tumor can grow both fast and slow. The more the tumor grows, the more pronounced the symptoms become. How serious a benign tumor is dependent on its location and whether it can be removed surgically. A malignant tumor is almost always serious, as it often is difficult to remove the entire tumor. However, in some cases the tumor can be kept in a state of remission with radiation or chemotherapy, while other types will result in death within a short time. Metastasis to the brain is often very serious, as it is the result of the spread of a malignant tumor somewhere else in the body.

A very serious complication connected with increased pressure inside the skull is the risk that the brain can be pushed downwards through the opening where the spinal cord runs through the bottom of the cranium. This is called herniering or incarceration and will result in death within a very short time.

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