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 causes? | What are the symptoms? | How common are brain and spinal cord tumours? | Information reviewers
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 most important organ in the body because it controls all voluntary and involuntary processes, such as 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 functions, many of which are essential to staying alive. 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 is part of the spinal canal, along with fat, connective tissue and blood vessels. Bony vertebrae protect the spinal canal.
Both the brain and spinal cord are surrounded by membranes called meninges. Inside the skull and vertebrae (spinal column), the brain and spinal cord float in liquid called cerebrospinal fluid.
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:
Glial cells, or neuroglia, are the other main type of cell 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 and oxygen to neurons and get rid of dead neurons and germs.
A tumour occurs when cells in the central nervous system grow and divide in an uncontrollable way, forming a lump. The lump 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, but sometimes it is difficult to tell the difference between them.
Benign tumours usually have slow-growing cells and clear borders (margins), and they rarely spread. However, they may be found in essential areas of the brain that control vital life functions, which can make them life-threatening.
Malignant tumours usually grow rapidly and spread within the brain and spinal cord. Malignant brain tumours can also be life-threatening. About 40% of brain and spinal cord tumours are malignant
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.
The causes of most brain and spinal cord tumours are unknown. However, there are a few known risk factors for malignant brain tumours:
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 or you may not take much notice of them. They 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.
Every year about 1,400 malignant brain tumours are diagnosed in Australia. About 100 of these cases are in children.
About 80 people are diagnosed with other malignant central nervous system tumours, including malignant spinal tumours. About one in five of these are in children.
Data about benign brain and spinal cord tumours are not collected, but an estimated 2,000 people - including children - are affected every year.
Information reviewed by: Prof. Michael Besser AM, Consultant Emeritus in Neurosurgery, Royal Prince Alfred Hospital & The Children's Hospital at Westmead; Lindy Cohn, Helpline, Cancer Council NSW; Laraine Cross, Senior Clinician, Social Work, Calvary Mater Newcastle; Christine and Richard Harris, Christine and Gordon Holding, Consumers; Marina Kastelan, Brain Clinical Nurse Coordinator, North Shore Private Hospital; Lorna O'Brien, Helplline Manager, Cancer Council NSW; and Karen Robinson, Neuro-oncology Care Coordinator, Liverpool Hospital Cancer Therapy Centre.