Diagnostic procedures and results Flashcards
What kind of diagnostic procedure is useful for increased intracranial pressures, and delineates ventricals, localizes tumors?
ventriculography
- xrays of skull after injection of air into lateral ventricles
What is tomography?
layered xray exposures (horizontal or vertical)
What’s the difference between myelography and ventriculography?
ventriculography = xrays of SKULL after injection of air into LATERAL VENTRICALS
myelography = xrays of SPINE after injection of air or dye into SPINAL SUBARACHNOID SPACE
Does CT or MRI have radiation?
CT does, MRI does not
- CT is narrow x-ray beams transmitted through tissues of varying densities and precisely measured
- MRI is nuclear particles depicted in a strong external magnetic field
What’s the most superior imaging of the brain?
MRI
What is the primary diagnostic measure for examination of tumors, demyelination, and vascular abnormalities?
MRI
What are contraindications to MRI?
metal implants, pacemakers
When is a PET used?
allows for physiological mapping, a major clinical research tool for imaging cerebral blood flow, brain metabolism
What tool allows 3D localization with high spatial resolution?
MRI
Does a PET have better resolution than CT?
no, CT better, MRI best
What diagnostic tool delineates abnormalities impinging on the subarachnoid space?
myelgraphy (xrays of spine after injection of air into spinal subarachnoid space)
What diagnostic measurement provides useful information about structural disease of the brain, especially when seizures are present or likely?
EEG (electroencephalography)
What tool is useful for imaging the lumen of carotid artery and analyzing flow, detection of plaques in carotid arteries?
ultrasound (echoencphalogram)
- also measures position and shifts of midline structures
What level of the spinal cord are spinal punctures done?
below L1-2
What’s the purpose of a lumbar puncture?
1) withdraw CSF for chemical analysis
2) inject therapeutic agent for cancer or meningitis
3) measure ICP and spinal fluid dynamics
4) inject contrast medium for diagnostic procedure
A spinal tap is drawn from a patient that has a cloudy color and has 70mg/dL of protein. Is this typical? What could this indicate?
no - should be colorless/crystal clear
no - protein should be between 15-45 for adult, 15-100 for neonates
- high protein, cloudy appearance can occur with a tumor or inflammatory process
With meningitis and inflammatory processes, would you expect a higher or lower pressure with a CSF anaylsis?
high pressure for intracranial tumors, abscesses, miningitis, inflammatory processes, subarachnoid hemorrhage, cerebral edema, and thrombosis of venous sinuses
With severe dehydration, would you expect increased or decreased pressure in CSF?
decreased pressure for leaking CSF, subarachnoid block circulatory collapse, severe dehydration
What does EMG look at?
electrical activity from muscles, both at resting/active contraction states
Increased insertional activity in an EMG is indicative of what?
denervated muscle, many muscle diseases
What is nerve conduction velocity testing?
conduction velocities obtained by stimulating peripheral nerves through skin and recording muscle/ sensory nerve action potentials
How is NCV testing measured?
distance between two points is divided by conduction time
In what diseases might we see decreased conduction velocities?
peripheral neuropathies characterized by decreased myelination (think low conduction)
- GBS, chronic demyelinating polyneuropathy, charcot marie tooth disease
If we see a slowed conduction time with nerve conduction velocity testing, does that mean this person has a LMN issue?
not necessarily, could mean just focal compression of peripheral nerve
