Youth Cancer

Neourological Tests

A neurological examination assesses motor (movement) and sensory (ability to feel, see and sense items in the patients environment) skills.
  • These tests are normally used when a specialist is trying to rule out cancer in the brain or in the spine.
  • These tests assess the functioning of one or more of the cranial nerves which affect hearing and speech, vision, coordination and balance, mental status, and changes in mood or behavior.
  • It is not always state or the art equipment that detects this type of cancer. Tuning forks, flashlights, reflex hammers, ophthalmoscopes, and needles in the hands of a specialist are commonly used in diagnosing brain tumors.


Types of Neurological Examinations


Neurological x-rays

X-rays are used in assessing a patient’s chest and skull are often taken as part of a neurological work-up.  Specifically in neurological examinations an x-ray can detect any vertebral misalignment or fractures in the spine. Tissue masses such as injured ligaments or a bulging disc are not visible on conventional x-rays.


Fluoroscopy

A fluoroscopy is a type of x-ray that uses a continuous or pulsed beam of low-dose radiation to produce continuous images of a body part in motion. A fluoroscopy unit uses x-rays and an image intensifier to produce ‘real time’ 2D images, similar to a movie.


Angiography

Is an x-ray of the arteries and veins to detect blockage or narrowing of the vessels. A cerebral angiogram can detect the degree of narrowing or obstruction of an artery or blood vessel in the brain, head, or neck.


It is normally used to:

  • Examine an area of the brain
  • Determine the location and size of a brain tumour
  • Determine the location and size aneurysm
  • Determine the location and size vascular malformation


How is it performed?

  1. Normally takes up to 3 hours.
  2. Doctor anesthetizes a small area near the groin and then inserts a catheter (tiny tube that can be inserted in to a body cavity) into a major artery located there.
  3. The catheter is threaded through the body and into an artery in the neck.  Once in place, the needle is removed and a guide wire is inserted.
  4. A small capsule containing a radiopaque dye (one that is highlighted on x-rays, making the picture clearer) is passed over the guide wire to the site of release.
  5. Dye is released and travels through the bloodstream into the head and neck.  A series of x-rays is taken and any obstruction is noted.
  6. Patients say they feel a warm to hot sensation as the dye is released.


Biopsy

A biopsy involves the removal and examination of a small piece of tissue from the body.

Muscle or nerve biopsies are used to diagnose neuromuscular disorders.

A brain biopsy, used to determine tumor type, staging and grading, requires surgery to remove a small piece of the brain or tumor and involves a lengthier stay in hospital to allow recovery.

Check out our general biopsy factseet for more information about biopsies.


Brain Scans (Neuroimaging)


Brain Scans are pictures taken of your brain.

They are mainly used to diagnose tumors, blood vessel malformations, or hemorrhage in the brain. There are two main areas where brain scans are of significant medical assistance.
  • Structural imaging: Examines the structure of the brain and the diagnosis of gross (large scale) intracranial disease (such as tumour), and injury.
  • Functional imaging: Used to diagnose metabolic diseases and lesions on a finer scale (such as Alzheimer's disease) and also for neurological and cognitive psychology research.


Computed tomography (CT scan)

A neurological CT scan are a painless process used to produce rapid, clear two-dimensional images of the brain and spine.

People who are claustrophobic may have difficulties with this form of scan.

Electroencephalography (EEG)

Electroencephalography is a bran scan that monitors brain activity through the skull.

An EEG is used to help diagnose brain tumours.
 
Prior to undergoing an EEG, the person must avoid caffeine intake and prescription drugs that affect the nervous system.

How is it performed?

  1. A series of cup-like electrodes are attached to the patient’s scalp, either with a special conducting paste or with extremely fine needles.
  2. The electrodes (also called leads) are small devices that are attached to wires and carry the electrical energy of the brain to a machine for reading.
  3. A very low electrical current is sent through the electrodes and the baseline brain energy is recorded. Patients are then exposed to a variety of external stimuli—including bright or flashing light, noise or certain drugs—or are asked to open and close the eyes, or to change breathing patterns.
  4. The electrodes transmit the resulting changes in brain wave patterns, that can be examined
  5. Patients normally take this test in a chair or on a bed, as movement and nervousness can change brain wave patterns. 


Evoked potentials (also called evoked response)

An evoked potential test measures the time it takes for nerves to respond to stimulation. The size of the response is also measured.

They can be used to confirm brain tumours.

How is it performed?

  1. Two sets of needle electrodes are used to test for nerve damage.
  2. One set of electrodes, is used to measure the electrophysiological response to stimuli.
  3. The other set of electrodes are attached to the part of the body to be tested.
  4. The Doctor records the amount of time it takes for the impulse generated by stimuli to reach the brain. 


Magnetic resonance imaging (MRI)

This test utilises computer-generated radio waves and a powerful magnetic field to produce detailed images of body structures. Normally used neurologically in the diagnosis of brain and spinal cord tumors, infection, and vascular irregularities that may lead to stroke.

An MRI of the spine shows the anatomy of the vertebrae that make up the spine, as well as the disks, spinal cord and the spaces between the vertebrae through which nerves pass.

Myelography

This is an x ray specifically dealing with the spinal canal. A water- or oil-based contrast dye is injected into the spinal canal to enhance x-ray imaging of the spine.


How is it performed?

  1. An anesthetic is injected in to a site between two vertebrae in the lower back.
  2. Cerebrospinal fluid is removed by spinal tap (see cerebrospinal fluid analysis, above)
  3. Contrast dye is injected into the spinal canal.
  4. X-rays are taken, most or all of the contrast dye is removed.

There is a slight risk of fluid leakage or allergic reaction to the contrast dye.

Positron emission tomography (PET)

A PET scan provides three-dimensional pictures of brain activity and a snap shot of the functional processes of the brain by measuring radioactive isotopes (called radiopharmaceuticals or radiotracers) that are injected into the bloodstream.

This test identifies tumors and diseased tissue, measures cellular and/or tissue metabolism, shows blood flow, and determines brain changes.

A low-level radioactive isotope is injected into the bloodstream and can be traced as the brain as it goes about its business performing different functions.

How is it performed?

Patient is injected with a small done of radioactive isotopes
  • The patient lies still while overhead sensors detect gamma rays in the body’s tissues, given off by the radioactive isotopes.
  • A computer processes the information.
  • Using different compounds, more than one brain function can be traced simultaneously.