Unit 1: Neurological Assessment: Diagnostic Studies

Question 1

Radiographic Procedures

Answer 1

• x-ray studies or radiographical procedures
• assesses the skull and spinal column
• assesses for fractures, compression, stenosis, and malformation
• can identify areas of injury or trauma
• preparation: explaining rationale and expected results of procedure
• nurse assists with appropriate safe positioning
• close monitoring of the patient who has suspected cervical-spinal cord injury b/c of potential of devastating injury and paralysis if damage to spinal cord occurs
• pt should be immobilized w/ hard collar until spinal cord injury is r/o
• Types: CT, PET, MRI, MRA, EEG, Cerebral Angiography, CTA, Evoke Potential, LP, Myelography, Biopsy

Question 2

Computed Tomography (CT)

Answer 2

• cross-sectional images that are viewed as cuts or slices; visualization of the brain, spine
• orbits in a quick, noninvasive manner
• used to assess for bleeding, edema, or masses
• required screening test for suspected ischemic stroke to r/o hemorrhagic stroke prior to receiving thrombolytic (clot-buster) therapy
• used to evaluate treatment and resolution of injuries
• done prior to a MRI or if MRI is contraindicated
• w/ or w/o contrast

Question 3

Pre-Procedure: Nursing Implications for a Computed Tomography (CT) Scan

Answer 3

• Explain procedure
• Assessing the potential need to medicate the patient for anxiety (the patient is required to lie still on a hard table with the head secured, may cause feelings of claustrophobia)
• Ensure a patent IV line in place
• Checking for allergies to iodine (shellfish, or dyes), b/c contrast contains iodine
• Monitoring BUN and creatinine to assess kidney function prior to receiving contrast b/c it is toxic to the kidney and can impair renal function
• Assess for diabetes mellitus and the use of metformin in the management of type 2

Question 4

Post-Procedure: Nursing Implications for a Computed Tomography (CT) Scan

Answer 4

• Administering IV fluids/ increasing the intake of oral fluids to clear contrast medium from the system
• Monitoring for allergic reactions if contrast is administered

Question 5

Safety Alert: Contrast Dye and Metformin

Answer 5

• Contrast dye is nephrotoxic and can impair renal function
• Metformin is cleared through the kidneys, and if it is administered prior to the examination and the administration of contrast, this medication may result in renal impairment
• Metformin levels will remain elevated; can result in lactic acidosis
• metformin must be held 48 hours prior to and after CT scan or until renal function is determined normal via normal BUN and Creatinine levels

Question 6

Positron Emission Tomography (PET)

Answer 6

• involves the administration of the radioactive glucose tracer fluorodeoxyglucose (FDG), which detects areas of increased metabolic activity in the body
• sensitive test for detecting cancer; b/c rapidly dividing cancer cells absorb the tracer (FDG), making them detectable
• can identify acute infection
• immediately prior, an IV line is inserted and the tracer is administered

Question 7

Pre-Procedure Nursing Implications for Positron Emission Tomography (PET)

Answer 7

• NPO for at least 6 to 12 hours prior to test to limit metabolic activity r/t digestion
• No caffeine, alcohol, or tobacco for 24 hours prior
• Lie very still during exam to minimize metabolic activity
• After tracer administered, patient instructed to remain quiet in a dark room to allow the tracer to be distributed throughout the body while minimizing metabolic activity

Question 8

Post-Procedure Nursing Implications for Positron Emision Tomography (PET)

Answer 8

encouraging adequate fluid intake to clear the tracer from the circulation

Question 9

Magnetic Resonance Imaging (MRI)

Answer 9

• noninvasive
• painless
• uses magnetic fields to obtain images
• provides three-dimensional images
• offers clear visualization and detail of small structures
• w/ or w/o contrast
• if contrast, it is noniodine based, limiting issues w/ allergies and nephrotoxicity
• used to assess injuries of the brain and spinal column
• can diagnose tumors, infections, and bleeding
• useful in diagnosis of cerebrovascular accident (CVA); stroke

Question 10

Pre-Procedure Nursing Implications for Magnetic Resonance Imaging (MRI)

Answer 10

• Provide education about procedure
• Screening patient for presence of metal objects (keys, watches, credit cards, or phones); metal interferes with the magnetic field; safety hazard
• An implanted device that contains metal (pacemaker), makes the MRI contraindicated b/c magnetic field may disable the device
• Assessing the potential need to medicate for anxiety; requires pt to lie quietly in a tunnel-like chamber for up to 50 minutes; Velcro straps may be used to hold pt in position; may hear loud pounding or pulsating noises b/c of the operation of the scanner
• People who are claustrophobic may require sedation
• Headsets supplied to provide distracting music

Question 11

Post-Procedure Nursing Implications for Magnetic Resonance Imaging (MRI)

Answer 11

Encouraging adequate hydration after test if contrast is used to facilitate clearance through the kidneys

Question 12

Magnetic Resonance Angiography (MRA)

Answer 12

• type of MRI
• uses the radio-wave signal characteristics of flowing blood to get images of the body’s blood vessels
• used to determine presence of aneurysms, clots, dissections, or vessel stenosis
• pre and post op same for MRI

Question 13

Cerebral Angiography

Answer 13

• invasive
• intra-arterial
• involves administration of radiopaque dye through a catheter inserted in an artery (femoral)
• continuous imaging (fluoroscopy) is done to visualize the cerebral circulation
• evaluates cerebral and ocular vessel occlusion, carotid disease, aneurysms, arteriovenous malformations, and other vascular disorders

Question 14

Pre-procedure Nursing Implications for Cerebral Angiography

Answer 14

• NPO after midnight before procedure
• Takes 60 to 120 minutes
• Instructing that an IV catheter will be inserted prior to the procedure to provide hydration during and after procedure to clear the contrast
• Administration of IV contrast may cause a warm, flushed feeling
• Ensure Informed consent obtained
• Completing a neurological, peripheral pulse, and vital signs assessment prior to procedure; establish a baseline
• Education about risk factors; stroke d/t potential for thrombus dislodgment, risk for impaired peripheral circulation distal to the arterial catheter placement
• Assess for allergies to contrast dye, iodine, and seafood b/c contrast dye contains iodine
• Evaluating Renal function parameters (BUN and Creatinine) prior to IV contrast administration b/c contrast is nephrotoxic
• Assess use of anticoagulants b/c place pt at risk for bleeding during and after angiogram
• Administer IV sedation as ordered

Question 15

Post-Procedure Nursing Implications for Cerebral Angiography

Answer 15

• Monitoring vital signs and neurological status
• Assess puncture site and pulses distal to the catheter insertion q 15 minutes for the first hour, then every hour as ordered
• Maintaining Pressure on arterial puncture site for 15 to 20 minutes after removal to avoid bleeding or hematoma formation at the site
• Ensure patient keeps the leg straight
• Maintains bedrest for 3 to 12 hours as ordered post-procedure and after catheter removal to avoid bleeding or hematoma formation at the catheter insertion site
• Maintain IV fluid hydration post-procedure to help clear contrast dye from the circulation
• Monitor for bleeding, hematoma formation, or infection at catheter-insertion site
• Monitoring Renal Functioning (BUN and Creatinine)

Question 16

Computed Tomography Angiography (CTA)

Answer 16

combines the technology of a CT scan (cross-sectional images of the brain) and traditional cerebral angiography (enhanced visualization of cerebral vasculature through the IV injection of contrast dye)

• evaluates cerebral vasculature
• less invasive b/c contrast is injected into a vein rather than an artery
• pre and post procedure same as CT scan

Question 17

Electroencephalography (EEG)

Answer 17

• inexpensive
• noninvasive
• uses 8 to 24 scalp electrodes to trace the spontaneous electrical activity of the brain
• diagnostic test for seizure activity and other abnormalities in electrical activity
• used as a part of sleep studies, to evaluate the unconscious patient, or determine brain death

Question 18

Pre-procedure Nursing Implications for Electroencephalography (EEG)

Answer 18

• No caffeine consumption for 8 to 12 hours prior to the test
• Wash hair night before and morning of test; avoid use of hair products
• Providing patient support as necessary during the test

Question 19

Evoked Potential

Answer 19

• Painless
• Noninvasive
• Measures the speed and size of nerve conduction generated by the nervous system in response to stimuli
• Electrodes are attached to the scalp and to different areas on the body depending on type of test being conducted; stimulus varies depending on test
• Visual evoked potentials: use visual test patterns as stimuli; indicated for optic neuritis, masses, or tumors
• Auditory brainstem evoked responses: stimulated by sounds; to test for CN VIII (acoustic) nerve damage
• Somatosensory evoked potential: nerve conduction in the arms and legs; done with mild electrical stimulation; electrodes placed on wrist or knee
• Sedation often required for somatosensory evoked potentials b/c the electrical stimulus may be painful

Question 20

Pre-procedure Nursing Implications for Evoked Potentials

Answer 20

• wash hair the night before and morning of the test
• avoid hair products prior to test
• offering patient support as necessary during the test

Question 21

Lumbar Puncture

Answer 21

• most common procedure done to obtain a sample of cerebrospinal fluid (CSF) for analysis and to measure intracranial pressure
• can also be used for the administration of spinal anesthesia and intrathecal medications
• used to remove CSF to reduce pressure
• invasive
• insertion of a spinal needle into the L3 and L4 space of the spinal column below the level of the spinal cord
• patient positioned laterally (on the side) in bed, drawing knees up toward the chest
• also be done with the patient leaning across a bedside table with the back arched
• Increased Intracranial pressure may indicate CSF obstruction or overproduction
• Presence of abnormalities in glucose and protein as well as cloudy color may = infection
• Presence of breakdown products of RBCs (xanthochromia), or frank blood, may indicate subarachnoid hemorrhage or a traumatic tap

Question 22

Pre-procedure Nursing Implications for Lumbar Puncture

Answer 22

• Education explaining lumbar puncture
• Ensure antiplatelet or anticoagulation medications are held prior to test to reduce risk of bleeding
• Checking coagulation studies prior to test
• Ensure informed consent obtained
• Provide supportive care as necessary during test

Question 23

Post-Procedure Nursing Implications for Lumbar Puncture

Answer 23

• Ensure bed rest for 4 to 6 hours after the test to help prevent CSF leakage; can cause severe headache
• Fluids to decrease headache intensity if present

Question 24

Safety Alert: To Avoid post-lumbar puncture headaches

Answer 24

• instructed to lie flat for 4 to 6 hours
• stay hydrated
• if a headache is severe and prolonged, a “blood patch” can be performed to help seal a CSF leak if present
• Blood patch: a small amount of the patients blood is injected into the site of the puncture, and the resultant clot seals the leak

Question 25

Myelography/myelogram

Answer 25

• Invasive
• Involves a lumbar puncture and injection of contrast medium into the subarachnoid space around the spinal cord
• X-rays are taken that enable visualization of the entire spinal column
• evaluates for lesions, cysts, injury, herniated discs, and masses/tumors

Question 26

Pre-Procedure Nursing Implications for Myelography/myelogram

Answer 26

• similar for those of a lumbar puncture
• checking for allergies to contrast dyes, iodine, or seafood
• informed consent obtained
• NPO for 4 hours prior to test
• hydration after test to promote excretion of contrast dye

Question 27

Biopsy (Brain)

Answer 27

• invasive
• done to obtain tissue samples for examination
• indicated to r/o or identify infection or abscesses
• identify tumor tissue
• needle, stereotactic, and open
• Needle biopsy: drilling a small hole into the skull, inserting a needle, and withdrawing tissue sample
• Stereotactic: use of specialized computer imaging that uses a three-dimensional coordinate system to pinpoint area being biopsied; needle is inserted at the precise location identified through imaging, and tissue is withdrawn
• Open Biopsy: involves removing bone from the skull in an operative procedure, exposing the tumor or tissue to be biopsied
• performed in OR under sedation or anesthesia