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A guide to terms used on this website

Glossary of terms

Aneurysm: a blood-filled, balloon-like bulge in the wall of a blood vessel.

AVM: arteriovenous malformation – a birth mark an abnormal connection between the arteries and veins in the brain that probably forms before birth.

Benign: without any signs of cancer and with no spread to nearby tissue or to other parts of the body. However, even a benign brain tumour can cause serious problems due to its location or size.

Biopsy: the removal of a small sample of a tumour for examination by a pathologist.

Brain neoplasm: another name for a brain tumour.

Brain stem: the brain stem is the most primitive part of the brain and links the cerebrum to the spinal cord. It also controls vital functions such as breathing and blood pressure control.

Brain stem glioma: a tumour in the brain stem occurs more frequently in children than in adults.

Cavernoma: a small pocket of venous blood. Because it comes from the veins rather than the arteries, it is at low pressure and can bleed and result in epilepsy or other disorders.

Cerebrospinal fluid (CSF): a clear fluid that circulates around the brain and the spinal canal.

Cerebellum: an area at the back of the brain that controls balance and body movements.

Cerebrum: the largest part of the brain, which divides into two parts – the left and right cerebral hemispheres. These are joined together by the corpus callosum, which relays information between the two halves.

Clinical trials: studies where patients test new treatments and therapies for their safety and effectiveness. Participation is voluntary and you have to meet certain criteria in order to be enrolled.

Computed tomography (CT): a scanning tool that combines X-ray with a computer to produce detailed images of the brain.

Cranial nerves: the 12 pairs of nerves responsible for various functions, including vision, eye movements, facial sensation and facial expression, hearing, smell, and taste.

Craniopharyngioma: a tumour of the pituitary stalk that most often affects younger patients.

Cranium: the bony covering that surrounds the brain. The skull consists of the cranium along with the facial bones.

Ependymoma: a tumour that develops from cells that line both the hollow cavities of the brain and the canal containing the spinal cord. They occur most often in children and are usually benign.

Functional MRI (fMRI): a technique that helps to pinpoint the functional areas of the brain and helps neurosurgeons to plan incisions, skull openings and tumour removal.

Glioma: a brain tumour that originates from nerve cells in the brain called glial cells. There are many different types of gliomas, such as astrocytes, mixed gliomas and optic nerve gliomas.

Haematoma: a localised collection of blood outside the blood vessels. In the brain, this is often the result of head trauma or a bleed from a vascular malformation.

Haemorrhage: bleeding. Inside the brain, it is usually referred to as a ‘cerebral haemorrhage’. It can be caused by a variety of factors, such as trauma or a stroke due to hypertension.

Hypothalamus: the part of the brain that acts as a messenger to the pituitary gland. It helps to regulate body temperature, sleep, appetite, and sexual behaviour.

Magnetic Resonance Imaging (MRI): medical equipment that uses a magnetic field to capture a three-dimensional image of the brain.

Malignant: cancerous – may spread into nearby tissue or travel to other parts of the body.

Medulloblastoma: a kind of malignant tumour occurs more often in younger patients.

Meninges: protective layers of tissue that surround the brain and spinal cord.

Meningioma: a tumour in the meninges. They are usually slow-growing, benign and seen more often in females.

Metastases: malignant tumours that have spread from another part of the body. They are often known as ‘secondaries’.

Neuroendoscopy: allows surgeons to work inside the brain with a small incision and minimal trauma.

Pineal tumour: a tumour near the pineal gland, which is located deep within the brain. There are many different kinds of pineal tumour, some malignant and some benign.

Pituitary tumour: a tumour within the pituitary gland. Because the pituitary gland supplies a wide range of hormones, a tumour in this site can result in a wide variety of symptoms, including amenorrhoea, galactorrhoea abnormal body growth or hyperthyroidism.

Primary brain tumour: a tumour that originates within the brain (such as a glioma) as opposed to metastases or ‘secondaries’, which are secondary to a tumour elsewhere.

Residium: the part of a tumour that can’t be removed and is left in place. The reason is usually that it is usually wrapping an important blood vessel. If the residium regrows, it can often be treated with stereotactic radiotherapy.

Schwannoma: a tumour that is usually benign, can affect balance and hearing, and may cause facial paralysis.

Secondaries: metastases – tumours that are secondary to the original tumour, which is elsewhere in the body.

Stereotactic radiotherapy: a method of delivering highly focused radiation to a single point on a tumour site while avoiding healthy tissue. It is painless and does not create a wound.

Stereotactic surgery: a sophisticated, computer-based form of surgery where surgeons use 3D images of brain to precisely guide them to the tumour site.

Thalamus: a small area in the brain that relays information to and from the cortex and translates impulses related to pain, attention, and alertness.

Vascular tumours: Haemangioblastoma, rare benign tumours that arise from excess growth of blood vessels of the brain and the spinal cord.

Ventricles: four small cavities within the brain where cerebrospinal fluid is produced.