Diagnostics Tests Flashcards
What is the Latex Capsular Agglutination Test (LCAT)?
Detects polysaccharide capsule on crypto spores
Very sensitive and specific
What cell would you see in CSF with leptomeningitis?
Eosiniphils
What are radiographs most useful for?
Detecting bony lesions
Why should you sample CSF before myelogram?
To get accurate sample
Contrast will cause chemical meningitis
Complications of myelography?
Arrest
Seizures
Worsening neurological status
Benefits of CT
Rapid
Inexpensive
Can be performed under sedation
What makes contrast in CT image
Different tissue density
What makes contrast in MRI image?
Different proton behavior with different tissues
Disadvantage of MRI?
Slow
Require general anesthesia
Sometimes not an option (pacemaker, metal implants)
MRI is best for which diseases?
Brain disease
Intramedullay spinal disease/ tumors
Non-chondrodystrophoid or Type II IVDD
CT is best for which diseases?
Fractures, boney disease
Mineralized, type I IVDD
(Poor for caudal fossa and lumbosacral area)
Type of disc herniation seen with dachshunds?
Extrusion
Type of disc herniation seen in GSD?
Protrusion
Where is CSF produced? Stored? Drained?
Produced in choroid plexus
Stored in lateral, 3rd, 4th ventricles
Drained by arachnoid villi into venous sinuses
What are the contraindications of CSF collection?
Increased ICP
Lack of comfort/competency
What are the landmarks for cisternal puncture in CSF collection?
Occiput
Spine of C2
Wings of C1
What are the landmarks for lumbar puncture in CSF collection?
L5-6 in dog
L6-7 or L7-S1 in cat
What is a disadvantage of lumbar puncture in CSF collection?
Higher instance of blood contamination
What characteristics of CSF are important to evaluate?
Color and clarity
Total nucleated cell #
RBC #
Protein concentration
What is xanthocrhomia?
Yellow tinge of CSF, usually due to hemorrhage
Can last up to 4 weeks
Turbidity of CSF is usually due to
Increased protein concentration
What are the normal characteristics of CSF?
Clear, colorless
Nucleated cells: <5/ul, mononuclear
RBCs: 0
Protein: <25 mg/dL (cisternal) or < 40 mg/dL (lumbar)
What is albuminocytologic association?
Elevated CSF protein concentration in the face of normal CSF cell count
What tests for masitcatory myositis?
2-M Ab titer
What tests for myasthenia gravis?
Ach receptor Ab titer
Healthy muscle is electrically _____
Silent
Velocity of a nerve impulse depends on
Degree of myelination
Affected by age, limb temperature, limb length
Smaller dogs faster than large dogs
What does the F wave do?
Evaluated motor function of a nerve using orthodromic and antidromic stimuli
What are orthodromic stimuli?
Stimulus that reaches muscle fiber and elicits a strong response, indicative of a muscle contraction (M wave)
What is an antidromic stimulus?
Evokes small portion of muscle fibers causing a F wave
What is BAER tesitng?
Brainstem Auditory Evoked Response
Measure of conductive, sensoineural hearing and brainstem function
Uses up to 7 waves
What factors reduce amplitude of BAER?
Skull thickness and muscle mass
What breeds are prone to congenital deafness?
Australian cattle dog Australian shepherd Bull terrier Catahoula Dalmatian English cocker spaniel English setter
