Archive for the ‘Medical Dictionary’ Category

Brain Tumor

Friday, April 24th, 2009

What is a brain tumour ?

A brain tumour is a heap of anomalous tissue growing in any part of the brain. For some indefinite reason, some brain cells grow in an uncontrolled manner and develop these tumours. These tumours can occur from any part of the brain, spinal cord or the nerves. Generally these tumours can be separated into benign and malignant tumours.
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Benign tumours develops slowly and never reach to other parts. However, as they gradually expand in size they can produce stress the normal brain and disturb mental and bodily functions. A few of the benign tumours known are: meningiomas, pituitary adenoma, craniopharyngioma, epidermoid cysts, neurocytoma, haemangioma, pilocytic astrocytoma, etc.
Malignant tumours or cancers are hostile tumours that develops fast and penetrate into the surrounding brain and at times reach to the other parts of the brain or spine. There are several types of malignant brain tumours similar to High Grade Astrocytoma/Glioma, ependymoma, PNET, medulloblastoma, lymphoma, Germ cell tumours. By insistent and timely therapy some of these can be cured.

Symptoms Commonly Observed:

  • Limb weakness and some abnormal feeling in the limbs can be a symptom of a tumour in particular parts of the brain mainly in and around the motor or sensory cortex. Usually the opposite side gets affected i.e right-sided weakness by a tumour in the left motor cortex.
  • Wobbly walking or imbalance (ataxia) can occur if the tumour is in the cerebellum or any other part of the brain.
  • Eyesight could become unclear or sometimes lost if the optic nerve is squashed or enlarged (Papilloedema).
  • Sometimes a squint or dual vision (diplopia) can develop if the nerves moving the eyes be exaggerated.
  • Current or long term memory could get faint.
  • Speech: Capacity to grasp (sensory aphasia) or express (motor aphasia) could be affected by tumours in particular parts of the brain. At times the person can understand but can not express in proper way and can not get the correct words.
  • Distorted behaviour, exhaustion, sleepiness, and loss of consciousness are several other symptoms of brain tumours.

Methods to detect a brain tumour:
The majority symptoms explained above are vague and can be caused by various other diseases. A thorough history and medical investigation is initialy done by the doctor and if a brain tumour is alleged then more tests as CT or MRI scan, angiogram, CSF test, hormonal blood test or EEG can be done.
CT or MRI Scan makes special X-ray films that show the complete structure of the brain and spine and pick up any malformation. To obtain a clearer picture, Iodine or Gadolinium diverge dyes are given intravenously. A number of people can develop an allergic effect to the iodine contrast agent and you must every time tell the doctor if you get any allergies. The extra expensive non-ionic diverge agents diminish the risk of allergic reaction. There is a strong magnetic field during the MRI scan and you should tell the doctor if you have any Pacemaker or metallic clip or prostheses inside your body. For these scans which require about half an hour, the patient lies down on the couch of thes CT or MRI machines. The couch moves the patient in the large hole or tunnel of these machines. The entire procedure is painless but the sound produced by the MRI machines can be disturbing for some patients. Through the scan the patient shouldn”t move and for kids who may move a lot, sometimes a slight anaesthesia is given.
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  • Angiogram is an X-ray taken after injecting an iodine dye in catheters positioned into the arteries. This shows the particulars of the blood supply to the tumour. For vascular deformity like AVM it is necessary to plan embolisation, surgery or stereotactic radiation.
  • Cerebro Spinal Fluid (CSF) Study is done subsequent to removal the CSF from the spine with a long needle (lumbar puncture). This is done in specific tumours which have a high possibility of diffusion to the spine or to prohibit infections or bleeding.
  • Hormonal Blood Tests are done for tumours such as pituitary adenoma, craniopharyngioma, optic chiasmal or hypothalamic glioma.
  • Electroencephalogram (EEG) is seldom done to examine the sample of seizures.

T cell

Wednesday, January 21st, 2009

T-cells are part of the acquired immune system. They circulate through the blood and are responsible for detecting and destroying the body’s own cells that are either infected with a virus or otherwise diseased (such as in cancer). They also help with B Cell immunity. There are three major types of T cell: Helper T cells, Cytotoxic T Cells and Suppressor T Cells.

Tachycardia

Wednesday, January 21st, 2009

Tachycardia is a form of cardiac arrhythmia which refers to a rapid beating of the heart.

Tar

Wednesday, January 21st, 2009

Tar is a component of cigarette made up of a number of chemicals, including several carcinogens (cancer-causing agents).

Tardive dyskinesia

Wednesday, January 21st, 2009

Tardive dyskinesia is a condition which may be experienced by patients taking antipsychotic medications. It is characterized by involuntary dyskinetic movements such as uncontrollable jerking or twitching of the arms and legs. This requires prompt medical attention.

Tartrazine

Wednesday, January 21st, 2009

Tartrazine is an artificial food colouring (102). Tartrazine is commonly used to produce a yellow colour, though it can be mixed with other food colours to produce shades of green. It is often used in confectionery, soft drinks, corn chips, cereals, custard, ice cream, cordial, some rices, mustard, marmalade, and many snack foods.

Tectorial membrane

Wednesday, January 21st, 2009

The tectorial membrane is where the receptor hair cells are embedded in the ear.

Temporal Lobe

Wednesday, January 21st, 2009

The  temporal lobe , one of the five lobes of the brain , is the the region below the lateral sulcus . The temporal lobe’s major functions include: interpretation and comprehension of language and higher-order interpretation and processing of visual information.

Tendinitis

Wednesday, January 21st, 2009

Tendinitis refers to inflammation of a tendon (a strong flexible cord attaching a muscle to a bone), most commonly from overuse but also from infection or rheumatic disease.

Tendon

Wednesday, January 21st, 2009

A tendon is a strong flexible cord of fibrous connective tissue that usually attaches a muscle to a bone.