Diagnostics in Neurology Flashcards
_____ is a useful tool for assessing the patency or
extent of carotid artery atherosclerotic disease
Carotid Duplex Ultrasound
Advantage to Carotid Ultrasound
Advantage of being able to measure the
thickness of intimal-medial arterial wall.
Angiography
Angiography provides the ability to visualize
the vasculature of the brain, which can be
helpful when diagnosing stenosis, full
blockage, aneurysms, etc
Angiography options:
○ Cerebral Angiography
■ Historic gold standard that remains the
definitive pre-op tool for aneurysms
○ CT Angiogram (CTA)
○ MR Angiogram (MRA)
______ involves accessing the arterial system with
a catheter and then injecting radiopaque dye while Fluoroscopy of the skull is obtained and recorded.
Cerebral angiogram
____ also involves radiation, but can be obtained faster and with less vascular invasion
CT Angiogram
______ uses the same technology as a regular MRI, but intravascular MR contrast is pushed through a catheter during the MR machine spin
MR Angiogram (MRA)
Administering contrast for CT and MR angiograms
● Contrast administration for both CT and MR Angiograms is
administered to the patient through a simple intravenous line.
Administering contrast for angiography using fluoroscopy
● For traditional Angiography using fluoroscopy, the contrast is
administered only at the area being imaged, which requires a long
catheter be inserted and fed through a vessel in the groin or wrist
For all angiography studies, ensuring the patient has ____ prior to the imaging study is important, especially if the patient is elderly, diabetic, or other significant comorbid conditions.
adequate kidney function
Angiography of the carotids and
vertebral arteries is generally
performed for definitive
assessment of ______
carotid artery
stenosis, especially before surgical
intervention
_____ are the two most commonly used imaging procedures in Neurologic medicine
MRI and CT
Nerve Conduction Studies
● Nerve Conduction Studies comprise a combination of measurements as a type of electrodiagnostic study.
○ Usually (but not always) performed in combination with electromyography (EMG)
Nerve Conduction Studies can help diagnose _____
peripheral neuropathies, entrapment syndromes (like Carpal Tunnel Syndrome), and radiculopathies- Conditions of the peripheral nerves
Nerve Conduction Studies process
● For this test, surface electrodes are placed at different locations along
specific peripheral nerves.
● The nerve is then stimulated with an
electrical impulse at one site and
recorded at the electrode.
○ Measures whether or not the nerve
is conducting normally
Electromyography (EMG)
● Usually in addition to the Nerve Conduction Studies, the needle EMG specifically measures the response of the muscle to lower motor
neuron innervation and stimulation (can help diagnose myopathies).
Electroencephalography (EEG) process
● Several sensitive electrodes are placed over the scalp and the tracing received during the EEG depicts the electrical activity occurring along
the surface of the brain
What does wafeform information tell us on an EEG?
● This information about waveform frequency and shape is combined with the age of the patient, state of alertness or sleep, and scalp location to determine pathologic or diagnostic significance
The ____ is the key characteristic that defines normal versus abnormal EEG rhythms
frequency of the wave
Most waves of _____ are normal EEG findings in the awake adult
8 Hz or higher
____ is the essential
component in the evaluation
of seizure disorders
EEG
Evoked Potential Testing
● Evoked Potentials (EPs), also known as Evoked Responses, measure the electrophysiologic responses of the nervous system (using EEG) to a certain type of environmental stimulus
Types of Evoked Potential Testing
○ Visual Evoked Potentials
○ Short-latency Somatosensory EPs
○ Short-latency Brainstem Auditory EPs
Visual Evoked Potentials are used to evaluate the ability of the brain to _____
pass visual information from the retina to the occipital lobe
_____ measure EEG waves while
other electrodes on the skin of the face and
lateral femoral cutaneous dermatome
activate afferent sensory fibers
Somatosensory EPs
Brainstem Auditory EPs measure the functionality of the _____
auditory nerve and auditory pathways in the brainstem
Essentially a “super duper mental status exam”
Neuropsychological Testing
Neuropsychological Testing
Neuropsychological evaluation is a testing
method through which a neuropsychologist
can acquire large amounts of data about a
subject’s cognitive, motor, behavioral,
linguistic, and executive functioning
These evaluations provide quantifiable data
about reasoning and problem-solving
abilities, language comprehension, memory
and attention abilities, processing speed,
visual-spatial organization, planning, etc
Neuropsychological Testing
The indications for a lumbar puncture are:
○ Suspicion of Meningitis
○ Suspicion of Subarachnoid Hemorrhage
○ Suspicion of neurologic diseases like
Guillain-Barre syndrome and MS
○ Therapeutic relief of idiopathic intracranial
hypertension
Lumbar Puncture practice
● If performed at the correct level (L3-4 or L4-5),
the risk of neural tissue damage is minimal,
although some experience “jolts of pain” for a split second.
● Using the manometer that is provided in the LP
tray, you may choose to measure the “Opening
Pressure,” which correlates with intracranial
pressure (high with high ICP).
● Four vials are then passively filled with CSF as it
drips slowly out of the needle
Conditions associated with abnormal
CSF analysis include (but are not
limited to) the following:
○ Infectious diseases
○ Intracranial hemorrhage (SAH)
○ Inflammatory or autoimmune
diseases (MS, GBS, etc)
○ Primary or metastatic CNS cancers
CSF with a yellow tint indicates the likely presence of pus and raises immediate suspicion of _____
bacterial meningitis
