WHAT ARE BRAIN TUMOURS?

A brain tumour is an abnormal growth of cells inside the skull.

Primary brain tumours are tumours which arise from the brain. They can grow from the cells of the brain, blood vessels in the brain, nerves that emerge from the brain or the membranes covering the brain. Benign (non-cancerous) brain tumours are generally slow-growing tumours. They can exert potentially damaging pressure on the brain but they do not spread into the surrounding brain tissue. Malignant (cancerous) brain tumours are rapid growing and they spread into the surrounding brain.

Secondary or metastatic brain tumours grow from cancer cells that originate from a primary cancer located in another organ (eg. lung, breast or colon).

Both primary and secondary brain tumours can result in severe disability and cause death if the growth is left unchecked. All patients with symptoms of a possible brain tumour should be evaluated by a neurosurgeon for diagnosis and treatment.


WHAT CAUSES BRAIN TUMOURS?

A few genetically inherited diseases have been identified that can increase the risk of the development of brain tumours. For example, in the inherited condition known as Von Hippel-Lindau Syndrome, children, siblings and relatives can develop tumours in the cerebellum and other parts of the body such as malignant kidney tumours.

Research has shown identifiable genetic abnormalities in some brain tumours. Some tumours are also known to have an increased incidence in certain families.

However, in the vast majority of cases, the cause of brain tumours is unknown. There is at present no clear evidence that injury, chemical exposure, viral infection, mobile phone use, environmental factors or mental stress can cause the growth of brain tumours.

WHAT ARE THE SYMPTOMS OF BRAIN TUMOURS?

The symptoms may be generalized or localised.

Generalised symptoms are due to increased pressure exerted on the brain and include:

   A recurring headache that may worse in the morning
   Nausea and vomiting
   Seizures
   Increased drowsiness

Localised symptoms depend on the location of the tumour and include:

   Progressive weakness or numbness in the arms or legs
   Progressive difficulty with speech, hearing, concentration or vision, including double-vision
   Memory loss or a change in memory
   A significant change in personality or behaviour

Some of these symptoms may also be caused by other conditions besides brain tumours. It is therefore wise to seek a neurosurgical opinion should the symptoms persist.

WHO IS AT RISK OF DEVELOPING BRAIN TUMOURS?   

Brain tumours may occur at any age, but the tumours that occur in childhood are generally different from those diagnosed in adults.

HOW ARE BRAIN TUMOURS DIAGNOSED? 

A detailed clinical assessment including history of the symptoms and a physical examination, including a comprehensive neurological examination, is necessary. Specialised imaging tests such as Computed Tomography (CT scan), Magnetic Resonance Imaging (MRI) will usually be performed.

Occasional, special tests like cerebral angiogram (X-rays of the blood vessels of the brain), functional MRI scans and MRI tractography may be required.

These tests will reveal the tumour’s size, location and also proximity to critical structures such as the speech or motor areas of the brain. The information will provide the neurosurgeon with a tentative diagnosis of the tumour type and aid him to plan the surgical approach for it removal.

Surgery

In most cases, surgery using microsurgical techniques is required to remove as much tumour with minimal injury to the brain. Brain tissue is extremely delicate and can sustain permanent damage from excessive pressure or disruption of its blood supply. The risks of surgery include infection, bleeding, seizures, paralysis, coma and even death.

Sophisticated equipment is available to make surgery safe and effective. Use of a computerised navigation system allows the neurosurgeon to localise the tumour accurately and also to navigate around critical areas of the brain. The Operating Microscope facilitates the preservation of important nerves and blood vessels, thereby reducing the risk of injury. Ultrasonic aspirators are also available to facilitate tumour resection. A brain tumour can be treated through a small opening made in the skull using CT or MRI-guided stereotactic surgery. If the boundaries of the tumour cannot be easily identified the neurosurgeon may have to stop the tumour resection to minimize the risk of damaging normal brain.

Under special circumstances when the tumour is located in critical areas of the brain, usually speech or motor areas, the surgery may even be done with the patient under sedation but awake. The critical areas can be identified more clearly by stimulating the areas with a small electrical current and tumour removal is performed with constant monitoring of the patient’s speech or limb strength. The overall aim is to remove as much tumour as possible with least damage to the critical areas.

When the brain tumour is small and deep-seated, more extensive tumour removal may not be possible. In such situations, a stereotactic frame may be fixed and CT or MRI-guided biopsy performed. A small piece of tumour is taken and sent for diagnostic investigations.

Radiosurgery

For selected small tumours, Gamma Knife Surgery using very strong focused gamma rays can be given over a few hours to arrest tumour growth without the need for surgery.

Radiation Therapy

For cancerous brain tumours that cannot be completely removed, surgery may be followed by external beam radiation delivered by a linear accelerator over 2-6 weeks to destroy the remaining tumour cells.

Chemotherapy

Drugs that destroy or slow down the growth of tumour cells can be administered either orally or by intravenous injection. Hair loss, nausea and susceptibility to infection are potential side effects of chemotherapy.

REHABILITATION 

Recovery may at times be limited by the extent of damage caused by the tumour and by the brain’s ability to recover. Therapists are available to commence physiotherapy, occupational therapy and speech therapy in the wards. If there is persistent disability, the patient may be transferred to the Department of Rehabilitation Medicine or to a nursing care facility for a further period of rehabilitation to maximize the recovery process. To fully benefit from rehabilitation, the patient and family should maintain a positive attitude, set realistic goals and work steadily to accomplish each goal.

Disclaimer: This brochure is meant to be a guide only.