Brain & spinal cord tumours

Thursday 1 May, 2014

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On this page: The brain and spinal cord | Nervous tissue | What is a brain or spinal cord tumour? | What types are there? | What are the risk factors? | What are the symptoms? | How common are these tumours? 

The brain and spinal cord

The brain and spinal cord make up the central nervous system (CNS). The CNS receives messages from cells called nerves, which are spread throughout the body (in the peripheral nervous system). The brain interprets information and relays messages through the nerves to muscles and organs.

The brain is the one of the most important organs in the body because it controls all voluntary and involuntary processes, such as moving, learning, sensing, imagining, remembering, breathing, blood circulation and heart rate, body temperature, digestion, and bowel and bladder control (continence).

The main sections of the brain are the cerebrum (the largest part), the cerebellum and the brain stem. These parts play unique roles in the body’s essential functions. Deep within the brain is the pituitary gland. It controls growth and development by releasing chemical messengers (hormones) into the blood. These signal other hormones to start or stop working.

The spinal cord extends from the brain stem to the lower back. It consists of nerve cells and nerve bundles that connect the brain to all parts of the body through the peripheral nervous system. The spinal cord lies in the spinal canal. Bony vertebrae (spinal column) protect the spinal canal.

Both the brain and spinal cord are surrounded by membranes called meninges. Inside the skull and vertebrae, the brain and spinal cord float in liquid called cerebrospinal fluid (CSF).

A diagram of the brain and spinal cord

Nervous tissue 

The brain, spinal cord and nerves consist of billions of nerve cells called neurons or neural cells, which process and send information. Together this is called nervous tissue.

The three main types of neural cells are:

  • sensory neurons – respond to light, sound and touch
  • motor neurons – cause muscle contractions
  • interneurons – connect neurons in the brain and spinal cord.

Glial cells, or neuroglia, are the other main type of cells in the nervous system. There are several different types of glial cells, including astrocytes and oligodendrocytes.

Glial cells are the glue of the nervous system because they surround the neurons and hold them in place. The glial cells also supply nutrients to neurons and clear away dead neurons and germs.

What is a brain or spinal cord tumour?

A tumour occurs when cells in the central nervous system grow and divide in an uncontrollable way, forming a lump. It may press on or grow into different areas of the brain or spinal cord, which can cause various symptoms such as loss of movement. A tumour can be benign or malignant.

Benign tumours usually have slow-growing cells and clear borders (margins) to separate them from normal tissue, and they rarely spread. However, they may be found in areas of the brain that control vital life functions, and require urgent treatment.

About 40% of brain and spinal cord tumours are malignant. These life-threatening tumours usually grow rapidly and spread within the brain and spinal cord.

What types are there?

There are more than 100 types of brain and spinal cord tumours (also called central nervous system or CNS tumours). They are usually named after the cell type they started in.

  • Benign tumours – The most common types are pituitary tumours, meningiomas, neuromas, schwannomas, craniopharyngiomas, and pilocytic astrocytomas. Benign tumours can cause problems by pressing on the brain and spinal cord.
  • Malignant tumours – This includes low- and high-grade astrocytomas, oligodendrogliomas and ependymomas, and mixed gliomas, medulloblastomas and glioblastomas (also known as glioblastoma multiforme or GBM). Primary malignant tumours are usually confined to one area of the brain and CNS.
  • Metastatic brain tumours – These begin as a primary cancer in another part of the body before spreading to the brain. The most common types of cancer that can spread to the brain include melanoma, bowel, breast, kidney and lung cancer.

Some benign brain tumours can develop into a rapidly growing malignant tumour. This process is called malignant transformation.

What are the risk factors?

The causes of most brain and spinal cord tumours are unknown. However, there are a few known risk factors for malignant brain tumours:

  • Family history – It is possible to have a genetic predisposition to developing a tumour. This means that you may have a fault in your genes, usually passed down from one of your parents, that increases your risk. For example, some people have a genetic condition called neurofibromatosis, which causes nerve tissue tumours.
  • Radiotherapy People who have had radiation to the head, usually to treat another type of cancer, may be at an increased risk of developing a tumour. This may affect people who had radiotherapy for childhood leukaemia.
Electromagnetic radiation and brain cancer

Concerns about a link between mobile phones, microwave ovens and brain cancer have attracted community interest over recent years.

Evidence to date does not show that mobile phone use causes cancer. However, an association cannot be ruled out because the effect of long-term mobile phone use is yet to be studied.

People who are concerned about the risk should limit call time and/or use hands-free devices. Many authorities recommend limiting mobile phone use by children.

Microwave ovens have been in widespread use since the 1980s. There is no evidence that ovens in working order emit electromagnetic radiation at levels likely to be harmful to humans.

"I’ve wondered about a link between mobile phones and brain tumours. The jury’s still out, but I choose to err on the side of caution. I try not to use my phone in low-reception areas, and I send text messages or use the hands-free function when possible." – Gary

What are the symptoms? 

The symptoms of a brain or spinal cord tumour depend on where it is located and if it is causing pressure in the skull or spinal column. Sometimes, when a tumour grows slowly, symptoms develop gradually, so you may not take much notice of them. Symptoms may be similar to other illnesses, such as a migraine or a stomach bug (e.g. headaches or nausea).

Brain and spinal cord tumours may cause weakness or paralysis in parts of the body. Some people also have trouble balancing or have seizures

Other symptoms of brain tumours 
  • nausea and/or vomiting
  • headaches
  • drowsiness
  • difficulty speaking or remembering words
  • short-term memory problems
  • disturbed vision, hearing, smell or taste
  • loss of consciousness
  • general irritability, depression or personality changes – this is sometimes only noticed by family or friends.
Symptoms of spinal cord tumours 
  • back and neck pain
  • numbness or tingling in the arms or legs
  • clumsiness or difficulty walking
  • loss of bowel or bladder control (incontinence).

Most people who have common symptoms, such as a headache, do not have a tumour. However, new or worsening symptoms should be reported to your doctor.

A brain tumour can sometimes block the flow of cerebrospinal fluid around the brain and its spaces (cavities). When this happens, fluid can build up and put pressure on the brain. This is called hydrocephalus. The condition is most common in infants, but it can occur in some adults. It is usually treated with a shunt.

How common are these tumours?

Every year about 1400 malignant brain tumours are diagnosed in Australia. The most common type of tumour is glioblastoma multiforme or GBM. About 80 people are diagnosed with other malignant central nervous system tumours, including malignant spinal tumours.

Data about benign brain and spinal cord tumours are not collected, but they are more common than malignant tumours. An estimated 2000 people – including children – are diagnosed with a benign tumour each year.

About 100 children are diagnosed with malignant brain tumours each year – this is the second most common cancer in children. About 20 children are diagnosed with a spinal cord tumour. The section about caring for a child with a tumour may be helpful. 

Reviewed by: A/Prof Kate Drummond, Neurosurgeon, Divisional Director of Neuroscience and Cancer and Infection Medicine, Director of Junior Surgical Training, The Royal Melbourne Hospital, VIC; Dr Dianne Clifton, Psychiatrist, Psycho-oncologist and Director, Department of Psychosocial Cancer Care at St Vincent’s Hospital, VIC; Dr Anthony Dowling, Medical Oncologist, St Vincent’s Hospital, VIC; Kate Fernandez, Clinical Nurse Coordinator, Central Nervous System Tumours, Women’s and Children’s Hospital, SA; Carmen Heathcote and Yvonne Howlett, Helpline Operators, Cancer Council Queensland, QLD; Dianne Legge, Brain Tumour Support Officer, Cancer Services, Olivia Newton-John Cancer and Wellness Centre, VIC; Scott Nussey, Consumer, SA; Dr Claire Phillips, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC; and Janine Rhodes, Coordinator, Brain Tumour Support Service, Cancer Council Queensland, QLD.

Updated: 01 May, 2014