Brain Tumours - Symptoms & Causes

What are brain tumours?

Brain tumours are abnormal growths in the brain that occur when cells divide uncontrollably.

There are more than 150 types of brain tumours. Some of them are benign (non-cancerous) while others are malignant (cancerous). They can be broadly classified into two main categories:

• Primary brain tumours originate from within the brain, such as the brain cells, membranes surrounding the brain (meninges), nerves or glands.
• Secondary brain tumours occur when cancer from another part of the body, such as the breast or lungs, spreads to the brain. They are also known as metastatic brain tumours and are more common than primary brain tumours.

Cancerous or not, brain tumours can increase intracranial pressure, affect the brain's functions, and cause a myriad of health problems.

What are the symptoms of brain tumours?

Brain tumours may or may not cause symptoms. Some brain tumours grow very slowly and are asymptomatic, while others may not cause symptoms until they grow large enough to interfere with the brain’s normal functions.

As such, symptoms of a brain tumour can vary greatly depending on the type of tumour, its location, size, and how rapidly it grows.

Symptoms may include any of the following:

• Regular headaches that increase in frequency or become more severe, especially in the morning
• Facial numbness or tingling
• Seizures (epilepsy) or convulsions
• Muscle weakness or gradual paralysis in one part of the body, such as the arm or leg
• Changes in mental state, personality or behaviour, such as difficulty thinking clearly or feeling confused and disoriented
• Loss of balance or clumsiness
• Loss of memory
• Unexplained nausea, dizziness or vomiting
• Problems with hearing or sight, including blurred or double vision or loss of peripheral vision

What causes brain tumours?

The exact cause of primary brain tumours remains unknown. Most brain tumours are believed to develop when abnormal cells in the brain grow and multiply uncontrollably, creating a mass or growth.

What are the risk factors for brain tumours?

There are several environmental and genetic factors that may increase your risk of developing brain tumours. These include:

• Exposure to high doses of ionising radiation, such as radiotherapy used to treat another cancer, or nuclear fallout.
• Increasing age, especially for those above 65 years old.
• Gender. Men are generally more likely than women to develop brain tumours.
• Ethnicity. Caucasians are at higher risk as compared to other races.
• Family history. About 5 – 10% of brain tumours are due to inherited conditions, such as neurofibromatosis.
• Weakened immune system. Immune system disorders, such as acquired immunodeficiency syndrome (AIDS), may increase the risk of developing brain and spinal cord lymphomas.

What are the complications and related diseases of brain tumours?

Brain tumours, even when benign, grow in size and increase intracranial pressure within the skull. This not only affects bodily functions controlled by the brain, but may also lead to dangerous complications such as hydrocephalus and brain herniation, which can result in coma and death.

How do you prevent brain tumours?

There is no known way to prevent brain tumours, though you can reduce your risk by avoiding environmental factors such as unnecessary radiation exposure.

If you have a close relative who has been diagnosed with a brain tumour, genetic testing may be performed to check for inherited conditions that are associated with brain tumours.