Central Nervous System Tumours
Central nervous system is a part of the nervous system comprising of the brain and the spinal cord. Together the brain and spinal cord, through an intricate system, conduct activities of various parts of the body, and maintain coordination among them. Tumours are mass of cells that may grow anywhere in the body and cause harmful effects. In children, most commonly occurring tumours are those growing in the brain and spinal cord and are termed as central nervous system tumours.
Tumours are classified on the basis of type of cells that originated the tumour. Furthermore, they are classified according to their degree of aggressiveness. Tumours that develop from glial cells are called glial tumours and each type of glial tumour is further classified based on their rate of growth and other factors. Glial cells are one of the two major cells found in brain; the other type is the neuron.
Spinal cord tumours are those that develop in the spinal cord itself, while vertebral tumours develop in the vertebrae (bones of the spine). A general classification of spinal cord tumours includes:
Intramedullary tumours: tumours that begin in the cells within the spinal cord such as astrocytomas.
Extramedullary tumours: Tumours that develop within the supporting network of cells around the spinal cord. Although they do not begin within the spinal cord itself, these types of tumours may affect spinal cord function by causing spinal cord compression and other problems. Such as, meningiomas.
All of these central nervous system tumours may fall under one of the two tumour categories;
Malignant (cancerous): These tumours grow very rapidly and can also affect surrounding tissues and parts of the brain.
Benign (non-cancerous): Their growth is slow and so they do not spread or affect surrounding areas of the brain
Tumours are also described by the stage at which they are present. These stages show the extent to which they have spread in the body and affected the surrounding tissues or organs. Stage of a tumour may be determined by scanning images of the tumour and also during the surgery.
The most commonly occurring tumours of the central nervous system are as follows.
It grows by cells called astrocytes and is more common in children between five to eight years of age.
It may develop in different parts of the brain like cerebellum; the back part of the brain responsible for coordination and balance, cerebrum; the top part of the brain that controls motor activities and talking, diencephalon; the central part of the brain that controls vision, hormone production, and arm and leg movement, the brain stem; which controls eye and facial movement, arm and leg movement, and breathing, the spinal cord; which controls sensation and arm and leg motor function.
Astrocytoma can be a high grade or low grade tumour.
Symptoms include clumsiness of one hand, gait changes (stumbling to one side), headache and vomiting
It grows from glial cells present in the brainstem. Most tumours grow in a part of brainstem called pons.
This tumour is very aggressive and is usually diagnosed after growing to a large size.
It usually grows in children between ages of five to ten.
Signs include double vision, facial weakness, difficulty walking, and vomiting
Many risks are associated with treating this tumour; hence alternative therapies are preferred over surgical intervention.
It is a type of brain tumour and grows from cells present in the ventricles of brain, causing hindrance in the normal flow of cerebrospinal fluid.
Symptoms include headache, vomiting, and loss of muscle control
It grows from cells in the cerebellum; the part of brain that is responsible for coordination and balance. But it can also spread along the spinal cord.
Symptoms may include headache, vomiting and fatigue.