Tumours

---Tumours - abnormal growths - can occur inside the brain itself or in its coverings beneath the skill. Because the skill cannot readily expand to make room for a growing tumour, this presses on the brain and causes damage that may lead to death if untreated.

---Various types of cell multiplying uncontrolled can create tumours inside the cranium. Some sprout from cancer cells that have migrated from another region of the body. Some tumours that originate inside the cranium are not produced by brain cells. These can arise from the blood vessels that supply the brain, from the meningeal sheaths that cover it, or from the pituitary gland inside it. However, most tumours are gliomas - so-called because they start in the glial ("glue") cells that support the neurons. Brain tumours rarely develop in the neurons themselves - the cells that all brain activity directly depends upon.

---Certain tumours grow faster than other. Some benign tumours expand so slowly that they may take years becoming a noticeable nuisance. On the other hand, a malignant tumour may grow so fast enough to change the brain fatally in months. Signs and symptoms often stem from pressure set up in the skull, especially when a tumour blocks cerebrospinal fluid flow so that liquid swells the cavities in the brain. Headaches, blurred vision, nausea and vomiting may all be brought on by a tumour of the brain (as well, of course, as by far less serious conditions). Eventually, a growing tumour also interferes with the normal working of the region of the brain affected. Smell, speech, touch, perception, movement of one side of the body, mental powers - any one of these faculties or others may become impaired. Also, many patients suffer convulsions similar to epileptic fits. Modern brain-scanning devices or other diagnostic tumours. The next step, if possible, is operating to remove it. Sometimes, the surgeon may have to cut a semicircle in the skull and raise this bony flap to reach the brain beneath. Using a blunt cutting instrument, he removed the diseases tissue, taking care not to tamper with the motor cortex, for that might leave the patient speechless and paralysed or weak one side down. Often, surgery can totally remove non-invasive - non-malignant - tumours such as malignant tumours can relieve pressure on the brain. Deep tumours can be attacked with X-rays, probes, or cauterising needles to destroy as much of the diseased tissue as possible.

Pituitary Tumour

---A pituitary tumour may be small and slow growing, but the effects can be drastic. The tumour interferes with the normal production of hormones, so hormone levels either fall or increase enormously. Massive overproduction of pituitary hormones can result in a form of giantish (acromegaly) I which the hands, face and feet become grossly increase in size. Too low a level of some pituitary hormones can cause dwarfism or diabetes insipidus. Only a small change in hormone levels in needed to upset completely essential body functions such as metabolism.

Meningioma

---A tumour of the meninges (a meningioma) is typically slow-growing but may prove fatal because the pressure it exerts on the brain. As with any brain damage, the effects of pressure vary according to the area of the brain that becomes distorted. A meningioma that presses on the left temporal lobe (as in the result in impairment of speech and understanding. As the tumour grows, more areas become distorted and greater pressure is set up. Commonly, a meningioma will cause distortion of the cavities containing cerebrospinal fluid. This results in blockage of the flow and a build-up of fluid, which itself causes even greater pressure.

Malignant Growth

Unlike a benign tumour which grows slowly, the cells of a malignant tumour (a cancer) spread rapidly and uncontrollably:

In normal tissue, cells are arranged in an orderly manner and divide to form new cell with the same characteristics and functions as the surrounding tissue.

A mutant cell or cancer cell from another part of the body starts dividing more rapidly than t he surrounding cells, and begins to form a growth that markedly differs from the original tissue.

As the cells continue to divide haphazardly, the tumour spreads until it dominates and finally replace the original tissue. Unchecked, the tumour will grow to fill all available space.

Pressure Relief

The only way to relieve the pressure caused by a tumour is by surgical removal of all or some of the tumour:

First, a semicircular incision is made through the flesh of the scalp.

Clamps are applied to the cut edge of the skin, which is pulled back to expose the scalp bone. Holed are drilled through this at intervals of 4 cm along the length of the incision, and the bone between then is sawn through.

Now the whole flap of bone and scalp can be pulled outward, using the jaw muscles, at its base as a hinge. The dura mater is cut through with scissors to reveal the surface of the brain

After removing the tumour, the bone flap is replaced and held tightly against the rest of the skull by wire structures.

The clamps are removed and the surface of the scalp is sutured together with fine silk thread.

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