Term
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Definition
Prep:
-Explain procedure to the patient
-Patient must remain still during procedure
-Assist with positioning
Purpose:
determine bony fractures, curvatures, bone erosion, bone dislocation, and possible calcification of soft tissue, which can damage the nervous system
Invasive or Non-Invasive
Head trauma and multiple injuries, one of the first priorities id to rule out cervical spine fractures. |
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Term
Cerebral Angiography (Arteriography) |
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Definition
Prep:
-Assess allergy to iodinated contrast
-NPO 4-6h. before the test
-Dentures and hearing aids must be removed
-Possible meds for relaxation
-Patient must remain still during the procedure
-Patient will feel warm/hot sensation when dye is injected
-Assess and document neuro signs, VS, and neurovascular checks
Purpose:
Visualize cerebral circulation to detect blockages in the arteries or veins in the brain, head, or neck.
Invasive or Non-Invasive
After the area has been numbed a catheter is inserted to the femoral artery and a contrast medium is injected and images are recorded to identify aneurisms, traumatic injuries, strictures/occlusions, tumors, blood vessel displacement from edema, and arteriovenous (AV) malformations. |
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Term
Computed Tomography
-CT Angiography
-Xenon Computed Tomography
-Introthecal Contrast-Enhanced CT |
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Definition
Prep:
-Guidelines for contrast
-Remain still
-Determine if patient is claustrophobic and if sedation is necessary
-Remove all hair accessories
-Inform patient that scanner makes noise
-Warm/Cool sensation when dye is injected
-Metallic taste
Purpose:
Accurate, quick, easy, noninvasive, painless, and least expensive method of diagnosis neuro problems. With the aid of a computer, pictures are taken at may horizontal levels, or slices, of the brain or spinal cord.
Distinguish bone, soft tissue (brain, vascular system, and ventricular system), and fluids (CSF or blood). Tumors, infarctions, hemorrhage, hydrocephalus, and bone malformations can also be detected.
Invasive or Non-Invasive
CT Angiography:
-Contrast IV dye before the scan.
-Identifies blockages or narrowing of blood vessels, aneurysms and other blood vessel abnormalities.
Xenon Computed Tomography:
-Evaluate blood flow to brain tissue
-Patient breaths Xenon, a colorless, odorless gas, while undergoing a standard CT scan.
Intrathecal Contrast-Enhanced CT Scan:
-Diagnose disorders of the spine and spinal nerve roots;
-Lumbar puncture to inject contrast dye
-Patient may have a headache after procedure. Assist with positioning. |
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Term
Precautions With Contrast Agents |
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Definition
-Agency guidelines and informed concent
-Food or fluid restrictions
-Allergies to contrast agents, shellfish or iodine
-Determining risk factors for contrast induced nephropathy
- pre-existing renaldisease
-diabetic nephropathy
-heart failure
-dehydration
-Drug Interference ( eg.metformin) |
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Term
Magnetic Resonance Imaging (MRI)
-Magnetic Resonance Angiography (MRA)
-Magnetic Resonance Spectroscopy (MRS)
-Diffusion Imaging (DI) |
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Definition
Prep:
-Same as CT scan
-Ask patient about any metal implants
-Remove all metal objects
-Check with radiologist about old tattoos (old ones contain lead)
-No metal in MRI room!
Purpose:
Multiple sets of images are taken to determine normal and abnormal anatomy.
-Produces images better than the CT scan.
-Does not use ionizing radiation but, instead, relies on magnetic fields.
-Images may be enhanced with the use of a non-iodine-based contrast medium (gadolinium).
Invasive or Non-Invasive
Magnetic Resonance Angiography (MRA):
-Evaluate blood flow and blood vessel abnormalities such as a arterial blockage, intracranial aneurysms, and AV malformations.
Magnetic Resonance Spectroscopy (MRS):
-Detect abnormalities in the brains biochemical process, such that which occurs in epilepsy, Alzheimer's disease, and stroke.
Diffusion Imaging (DI):
-Uses MRI technique to evaluate ischemia in the brain to determine the location and severity of a stroke. |
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Term
Positron Emission Tomography (PET) |
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Definition
Prep:
-Same as CT
-No caffeine, alcohol, or tobacco for 24h. before the test
-NPO 4-12h. before test (if diabetic, no insulin)
-No drugs that alter glucose metabolism (glucose solution)
-Insert 2 IV lines
Purpose:
Provides information about the function of the brain, specifically glucose and oxygen metabolism and cerebral blood flow. It evaluates drug metabolism and detect areas of metabolic alteration that occur in dementia, epilepsy, psychiatric and degenerative disorders, neoplasm's and Alzheimer's disease.
Invasive or Non-Invasive
-2-3 hour procedure, patient will be blindfolded and have earplugs.
-Patient will be asked to perform certain mental functions to activate different areas of the brain, |
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Term
Single-Photon Emission Computed Tomography (SPECT) |
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Definition
Prep:
-Similar to PET/CT
-Assess if patient has had recent other nuclear medicine screenings (may leave traces of radiopharmaceutical agent).
-Guidelines for contrast use
-Inject agent (gamma-emitting radionuclides) 1 hr. before scan
Purpose:
This test uses a radieopharmeceutical agent that enables radioisotopes to cross the blood-brain barrier. The scan is particularly useful in studying cerebral blood flow, amnesia, neoplasm's, head trauma, persistent vegetative state, or brain death.
Invasive or Non-Invasive
-Resolution of images are limited
-Injected with the material 1 hr before the scan.
-Patient is positioned on a x-ray table in a quiet dark room.
- Gamma cameras scan patients head and then images are downloaded to a computer.
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Term
Magnetoencephalography (MEG) |
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Definition
Prep:
Purpose:
Brain observed "in action" by measuring the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as super-conducting quantum interference devices (SQUIDs).
Invasive or Non-Invasive
- Greater accuracy than EEG because of the minimal distortion of the signal. |
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Term
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Definition
Prep:
-Testing is usually performed after exercise or exposure of the muscle to curare or to ischema
Purpose:
Identify nerve and muscle disorders as well as spinal cord disease. It is considered a nerve conduction velocity study (NCVSs)
Invasive or Non-Invasive
-Electrical test that assess the amplitude of the muscle's response and how much it diminishes with progressive stimulation.
-A decrease in amplitude of more than 10% between the 1st and 5th responses generally indicates the defective neuromuscular transmission characteristic of, but not unique to, MG. |
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Term
Electroencephalography (EEG) |
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Definition
Prep:
-Patient on reclining chair or bed
-16-24 electrodes are placed on their head
-Lie still with eyes closed
Purpose:
Records the electrical activity of the cerebral hemispheres and each recording represents the voltage changes in various areas of the brain (determined by recording the difference between two electrodes).
It is performed to...
-Determine general activities of cerebral hemispheres
-Determine origin of seizure activity
-Determine cerebral functioning in pathologic conditions other than epilepsy
-Differentiate between organic and hysterical or feigned blindness or deafness
-Monitor cerebral activity during surgical anesthesia
-Diagnose sleep disorders
-Determine brain death
Invasive or Non-Invasive
-Initial recording is while patient is still. The rest of the test engages the patient in activities (hyperventilation (seizure inducing), photic stimulation (seizure inducing), sleep (tests temporal lobe epilepsy)).
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Term
Evoked Potentials (Evoked Response)
-Auditory EP
-Visual EP
-Somatosensory EP
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Definition
Prep:
-Attach electrodes
Purpose:
Measure the electrical signals to the brain generated by hearing, touch, or sight. Used to assess sensory nerve problems and confirm neurologic conditions including MS, brain tumor, acoustic neuroma (small tumors of the inner ear), and spinal cord injury. Also used to test sight and hearing (usually in infants and young children), monitor brain activity among coma patients, and confirm brain death.
Invasive or Non-invasive
-One set of electrodes are attached to the patients scalp, and the other to the body being tested.
-A stimulus is applied and the amount of time it takes to reach the other electrode is recorded (a normal transmission time is instantaneous).
Auditory EP:
-Assess high-frequency hearing loss, diagnose any damage to acoustic nerve and auditory pathways in the brainstem, and detect acoustic neuromas.
-Patient sits in soundproof room with headphones.
-Clicking sounds are delivered to one ear while a masking sound is sent to the other.
Visual EP:
-Detect loss of vision form optic nerve damage
-Patient sits close to a screen and focuses on the center of a checkerboard pattern
-One eye is tested at a time
Somatosensory EP:
-Detect nerve or spinal cord damage or nerve degeneration from MS and other degenerating diseases.
-Tiny electrical shocks are delivered by an electrode to a nerve in a leg/arm. |
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Term
Cerebral Blood Flow Evaluation |
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Definition
Prep:
-Explain Test
-Ask physician in CNS depressants should be withheld 24h before the test
Purpose:
Measures CBF in many areas of the brain with the use of radioactive substances and is useful in evaluating cerebral vasospasm.
Increased local blood flow can be seen with any neuronal activity, such as reading, hand movement, seizures, and temp elevation. Local blood flow decreases with neurodegenerative disease, comas of metabolic origin, increased intracrainial pressure (ICP), or subarachnoid hemorrhage.
Invasive of Non-Invasive
-Inhaled or injected xenon defuses into the brain tissue.
-Patient receives various stimuli during the test |
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Term
Lumbar Puncture (Spinal Tap) |
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Definition
Prep:
-Explain procedure, noting discomfort with local anesthetic and pain in leg(s) when needle is inserted.
-Place patient in fetal position remaining still
-Cleans sight thoroughly
-Injection site determained
Purpose:
-Obtain CSF pressure readings with manometer
-Obtain CSF for analysis
-Check for spinal blockage caused by a spinal cord lesion
-Inject contrast medium or air for diagnostic study
-Inject spinal anesthetics
-Inject certain drugs
-Reduce mild to moderate increased ICP in certain conditions
Invasive or Non-Invasive |
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Term
Transcranial Doppler Ultrasonography |
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Definition
Prep:
-
Purpose:
Evaluates intracranial hemodynamics. Uses sound waves to measure the blood flow through the arteries. Valuable is evaluation cerebral vasospasm or narrowing or arteries
Invasive or Non-Invasive |
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Term
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Definition
Prep:
Purpose:
Used to diagnose neuromuscular disorders. They may also reveal if a patient is a carrier of a defective gene that could be passed onto children.
Invasive or Non-Invasive
-Under local anesthesia, an incision is made and needle is inserted to remove a small sample.
-CT or MRI is performed before a brain biopsy which involves injection of local anesthetic into the scalp, drilling a small hole through the scull, and inserting a hollow needle to obtain the small sample.
-All samples are observed under a microscope to identify abnormalities |
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