Craniotomy Health Dictionary

A disorder caused by the increased secretion of growth hormone by an ADENOMA of the anterior PITUITARY GLAND. It results in excessive growth of both the skeletal and the soft tissues. If it occurs in adolescence before the bony epiphyses have fused, the result is gigantism; if it occurs in adult life the skeletal overgrowth is con?ned to the hands, feet, cranial sinuses and jaw. Most of the features are due to overgrowth of the cartilage of the nose and ear and of the soft tissues which increase the thickness of the skin and lips. Viscera such as the thyroid and liver are also affected. The overgrowth of the soft tissues is gradual.

The local effects of the tumour commonly cause headache and, less frequently, impairment of vision, particularly of the temporal ?eld of vision, as a result of pressure on the nerves to the eye. The tumour may damage the other pituitary cells giving rise to gonadal, thyroid or adrenocortical insu?ciency. The disease often becomes obvious in persons over about 45 years of age; they may also complain of excessive sweating, joint pains and lethargy. The diagnosis is con?rmed by measuring the level of growth hormone in the serum and by an X-ray of the skull which usually shows enlargement of the pituitary fossa.

Treatment The most e?ective treatment is surgically to remove the pituitary adenoma. This can usually be done through the nose and the sphenoid sinus, but large adenomas may need a full CRANIOTOMY. Surgery cures about 80 per cent of patients with a microadenoma and 40 per cent of those with a large lesion; the rate of recurrence is 5–10 per cent. For recurrences, or for patients un?t for surgery or who refuse it, a combination of irradiation and drugs may be helpful. Deep X-ray therapy to the pituitary fossa is less e?ective than surgery but may also be helpful, and recently more sophisticated X-ray techniques, such as gamma knife irradiation, have shown promise. Drugs – such as BROMOCRIPTINE, capergoline and quiangoline, which are dopamine agonists – lower growth-hormone levels in acromegaly and are particularly useful as an adjunct to radiotherapy. Drugs which inhibit growth-hormone release by competing for its receptors, octeotride and lanreotride, also have a place in treatment.

See www.niddk.nih.gov/health/endo/pubs/ acro/acro.htm

www.umm.edu/endocrin/acromegaly.htm... acromegaly

A circular hole made in the SKULL using a special surgical drill with a rounded tip, called the burr. The operation is done to relieve pressure on the BRAIN. This pressure – raised intracranial tension – is commonly the result of blood collecting between the skull and the brain after a head injury. The presence of PUS or an increase in the amount of CEREBROSPINAL FLUID as a result of infection or tumours in the brain can also cause a potentially fatal rise in intracranial pressure which can be relieved by drilling a burr hole. A neurosurgeon may make several burr holes when doing a CRANIOTOMY, a procedure in which a section of the skull is removed to provide access to the brain and surrounding tissues. Archaeological evidence suggests that modern man’s ancestors used burr holes probably to treat physical ailments and mental illness.... burr (bur) hole

A collection of pus, surrounded by inflamed tissues, within the brain or on its surface. The most common sites are the frontal and temporal lobes of the cerebrum in the forebrain.

Brain abscesses may occur after a head injury, but most cases result from the spread of infection from elsewhere in the body, such as the middle ear or sinuses.

Another cause is an infection following a penetrating brain injury.

Multiple brain abscesses may occur as a result of blood-borne infection, most commonly in patients with a heart-valve infection (see endocarditis).

Symptoms include headache, drowsiness, vomiting, visual disturbances, fever, seizures, and symptoms, such as speech disturbances, that are due to local pressure.

Treatment is with antibiotic drugs and surgery.

A craniotomy may be needed to open and drain the abscess.

Untreated, brain abscesses can cause permanent damage or can be fatal.

Despite treatment, scarring can cause epilepsy in some cases.... brain abscess

An abnormal growth in or on the brain. Tumours may be primary growths arising directly from tissues within the skull or metastases (secondary growths) that have spread from tumours elsewhere in the body. The cause of primary brain tumours is not known. About 60 per cent are gliomas (frequently cancerous), which arise from the brain tissue. Other primary tumours include meningiomas, acoustic neuromas, and pituitary tumours. Most of these tumours are noncancerous, but their size can cause local damage. Certain types of primary brain tumour mainly affect children. These include 2 types of glioma called medulloblastoma and cerebellar astrocytoma. Primary brain tumours virtually never spread (metastasize) outside the central nervous system.

Symptoms include muscle weakness, loss of vision, or other sensory disturbances, speech difficulties, and epileptic seizures. Increased pressure within the skull can cause headache, visual disturbances, vomiting, and impaired mental functioning. Hydrocephalus may occur.

When possible, primary tumours are removed by surgery after opening the skull (see craniotomy).

In cases where a tumour cannot be completely removed, as much as possible of it will be cut away to relieve pressure.

For primary and secondary tumours, radiotherapy or anticancer drugs may also be given.

Corticosteroid drugs are often prescribed temporarily to reduce the size of a tumour and associated brain swelling.... brain tumour

A hole made in the skull by a special drill with a rounded tip (burr). A hole is made to relieve the pressure on the brain that often results from bleeding inside the skull, usually following a head injury. Burr holes may be made as part of a craniotomy and may be lifesaving procedures.... burr hole

n. a surgical instrument used to remove a circular area of tissue, usually from the cornea of the eye (in the operation of penetrating *keratoplasty) or from bone (for microscopical examination). It consists of a hollow tube with a serrated cutting edge. It is used during the preliminary stages of craniotomy.... trephine

Bleeding into the space between the inner surface of the skull and the external surface of the dura mater, the outer layer of the meninges. Extradural haemorrhage usually results from a blow to the side of the head that fractures the skull and ruptures an artery running over the surface of the dura mater. A haematoma (collection of clotted blood) forms and enlarges, causing an increase in pressure inside the skull and resulting in symptoms several hours or even days after the injury. Symptoms may include headache, drowsiness, vomiting, paralysis affecting one side of the body, and seizures. Untreated, extradural haemorrhage may be life-threatening.

CT scanning or MRI confirms the diagnosis.

Surgical treatment consists of craniotomy, draining the blood clot, and clipping the ruptured blood vessel.... extradural haemorrhage

Bleeding into the space between the outer and middle layers of the meninges, usually following head injury. The trapped blood slowly forms a large clot within the skull that presses on brain tissue. The symptoms, which tend to fluctuate, may include headache, confusion, drowsiness, and one-sided weakness or paralysis. The interval between the injury and the start of symptoms varies from days to months. Diagnosis is by CT scanning or MRI. In many cases, surgical treatment is needed. This involves drilling burr holes in the skull (see craniotomy), so that the blood can be drained out and damaged blood vessels repaired. If treatment is carried out at an early enough stage, the person usually makes a full recovery. A subdural haemorrhage that is small and produces few symptoms may not require any treatment. The affected

person is usually monitored with regular scans, and the clot may clear up on its own. (See also extradural haemorrhage.)... subdural haemorrhage