Exam 2 - Spinal Cord Disease Flashcards
if there is a lesion in the spinal cord at C1-C6, what would you expect to see in the animals gait?
long-strided gaits in all 4 limbs
-overextension
-UMN paresis
if there is a lesion in the spinal cord at C6-T2, what would you expect to see in the animals gait?
two engine gait
thoracic - short stride, LMN paresis
pelvic - long stride, UMN paresis
if there is a lesion in the spinal cord at T3-L3, what would you expect to see in the animals gait?
pelvic limb - long strided & harder to advance legs
if there is a lesion in the spinal cord at L4-Cd5, what would you expect to see in the animals gait?
normal thoracic limbs
pelvic limbs - short strided
what spinal cord lesions will have deficits in all 4 legs with postural reactions?
C1-C6 & C6-T2
what spinal cord lesions will have deficits in the pelvic limbs with postural reactions?
T3-L3 & L4-Cd5
T/F: mentation is normal in spinal cord disease as well as cranial nerve assessment
true
T/F: animals with cervical spinal cord disease often are more so ataxic/paretic in the pelvic limbs than the thoracic
true
what is schiff-sherrington syndrome?
extensor rigidity in the thoracic limbs without
thoracic limb paresis or ataxia occurs due to loss of the fasciculus proprius, which normally exerts an inhibitory effect on C6-T2 alpha
motor neurons
spinal shock may be present
what is spinal shock?
severe, acute T3-L3 myelopathy pelvic limb hyporeflexia that occurs because of the loss of facilitory input to LMNs at the lumbosacral intumescence
when & why is the panniculus reflex used?
assesses the cutaneous trunci & efferent output through the lateral thoracic nerve (C8-T1 nerve roots)
severe lesions in the T3-L3 spinal cord or loss of C8-T1 alpha motor neurons or associated nerve roots
with spinal cord injury, function is classically lost in what order?
- proprioception
- motor/urinary voiding
- superficial nociception
- deep nociception
if you do a CSF analysis & have a normal cell count & protein, what can you rule out?
meningitis & meningomyelitis
T/F: CSF abnormalities are not often specific to one etiology, so it is best used in combination with vertebral column imaging
true
radiographs are highly specific for what?
fractures
what are radiographs good for in spinal disease?
bone tumors & vertebral fractions
what are radiographs not great for in spinal disease?
disk herniation
how are lesions classified in myelograms?
- extradural
- intradural-extramedullary
- intramedullary
what are some reasonable uses for myelograms in spinal cord disease?
disk herniation & instability
what are the disadvantages in using myelograms in spinal cord disease?
artifacts, not a multi-planar technique, lesion misclassification
what are the adverse effects associated with myelograms?
seizures, hypotension, & death
what imaging modality is the standard of care for diagnosing vertebral fractures & luxation?
computed tomography
what are the potential disadvantages in using CT for spinal cord disease?
potential for missing soft tissue lesions & non-mineralized disks
if no lesions seen - consider IV contrast
T/F: CT is great for diagnosing lesions in the CNS
false
what is the imaging modality of choice for spinal cord/vertebral column pathology especially parenchymal lesions?
MRI
other than spinal cord/vertebral column pathology/parenchymal lesions, what else is MRI useful for?
lesions in the brain & vestibular system
what are the advantages of using MRI for diagnosing spinal cord disease?
more detailed location of the pathology, better evaluation of prognosis, & different weightings
the better soft tissue detail provided in MRI scans is better why?
better ability to:
-detect soft tissue masses
-detect subtle disk protrusion
-detect spinal cord edema & hemorrhage
in T1 weightings, ____ is hypointense (dark) & ____ is hyperintense (bright)
(fat/fluid)
fluid
fat
in T2 weightings, ____, ____, ___, & _____ may show up hyperintense (bright)
fluid, CSF necrosis, edema, & hemorrhage
MRI is the only imaging modality that can be used to diagnose what?
FCE & syringohydromyelia
in acute spinal cord injury, what is the primary injury?
initial mechanical insult the spinal cord suffers
what are the 2 generally most important sub-forms of primary injury?
compression & contussions
in spinal cord disease, what is secondary injury?
biochemical cascade that results because of the primary injury
what are the sub-classifications of secondary injuries?
- oxidative
- vascular
- immunological
- excitotoxicity
why should steroids not be used in treatment of any acute & severe traumatic spinal cord injuries?
they increase the risk of adverse effects, such as:
UTI development, gi ulcers, & diarrhea
if your treatment in an acute spinal cord injury is aiming to address the primary injury, what can that include?
laminectomy and/or stabilization
if your treatment in an acute spinal cord injury is aiming to address the secondary injury, what can that include?
fluid therapy & analgesia - OPIODS, NSAIDS, muscle relaxers, etc
what is the most important component of aftercare? why? what should it include?
nursing!!!
patients often will have significant disability
rotate the patient, ensure access to food & water, & evaluate bladder emptying because management may be necessary
how can you look to see if urinary function is normal in an animal with spinal cord injury/disease?
observe them, post-voiding ultrasound, post-voiding catheterization
what lesion location is associated with upper motor neuron bladder?
lesion cranial to S1 spinal cord
what injury severity is associated with upper motor neuron bladder?
usually animal is non-ambulatory
what is the pathogenesis of UMN bladder?
pons can’t sense when the bladder is full & signaling to the bladder is lost - sensory & UMN pathways are disrupted
what are the clinical signs & features of UMN bladder?
LMN pelvic signs, increased tone to the internal urethral sphincter, firm bladder because increased tone to the detrussor muscle, external urethral sphincter remains closed, & reflex dysynergia
what are the clinical signs & features of LMN bladder?
flaccid bladder, constant leaking of urine due to loss of innervation of pelvic & pudendal nerves, intact pathways to internal urethral sphincter, & loss of detrussor muscle function & LMNs to external urethral sphincter
what injury severity is associated with lower motor neuron bladder?
non-ambulatory patient
what lesion location is associated with lower motor neuron bladder?
lesion in S1-S3
what is the basic bladder treatment plan in spinal cord injuries?
eliminate over-distension with bladder expression or catheterization
UTIs - treating only when voluntarily voiding & preventing ascending infection/sepsis
pharmacotherapy
what is the first line of drugs used for UMN bladder?
alpha-antagonists to relieve internal sphincter spasticity
what 2 drugs are the most common alpha-antagonists used in UMN bladder?
phenoxybenzamine & prazosin
how does bethanecol work for UMN bladder treatment?
increases detrussor contractility & may also increase internal sphincter tone
why should you wait to use bethanecol until after the patient is on alpha-antagonists?
the bethanecol may increase internal sphincter tone which would add to your problems
what is your first choice of drug for LMN bladder?
bethanecol
can add alpha blockers if it’s ineffective
which of the following is true in an UMN bladder?
a. tone to the external urethral sphincter is reduced
b. alpha agonists are the best treatment
c. bethanecol is the best treatment
d. muscarinic tone is preserved
d. muscarinic tone is preserved
T/F: in an UMN bladder, the lack of parasympathetic ability to inhibit sympathetic control is what causes clinical signs
true
what are very important components to recovery in animals with spinal cord injuries?
physical therapy - active weight bearing, prevent disuse atrophy, passive range of motion, & can shorten recovery time
T/F: in some animals with spinal cord injury, cage restriction is required
true
why is cage restriction required in FCE recovery? what about post-surgical candidates & vertical column instability?
FCE - prevent self-inflicted trauma secondary to paresis or ataxia
post surgery/instability - extremely important for healing of surgical incisions, closure disk-associated annular tears, & will enable fusion in animals with vertebral column instability
why do you want to not overdo cage rest?
can lead to disuse atrophy
what type of IVD does this represent? what is it?
type II - slow process where the annulus fibrosis thickens up
PROTRUSION
what type of IVD does this represent? what is it?
type I - acute injury
EXTRUSION
what fibers make up the annulus fibrosis?
tough type II collagen fibers
when should conservative treatment be used for cervical disk herniation patients?
acute, single episode of neck pain & mild paresis or a client unwilling to consider surgery
what is the conservative treatment plan used for cervical disk herniation?
blood work + rads, ‘don’t know’ speech
cage rest, anti-inflammatories (NSAIDS), & analgesia
when should surgical treatment be used for cervical disk herniation patients?
multiple episodes or acute significant ataxia
what is the percentage of recovery in an animal with cervical disk herniation that is hyperesthetic only or has minimal ataxia?
prognosis >90% recovery
what is the percentage of recovery in an animal with cervical disk herniation that is non-ambulatory tetraparetic or tetraplegic?
prognosis 70-75%
what surgeries are performed to correct herniated cervical disks?
ventral slots & dorsal laminectomies
what is the agent that causes non-infectious inflammatory steroid-responsive meningitis?
unknown - likely auto-immune
what is the pathogenesis of non-infectious inflammatory steroid-responsive meningitis?
immune-mediated vasculitis of the leptomeningeal arteries with meningitis
infiltration of the CNS parenchyma sometimes present
what animals are typically affected by non-infectious inflammatory steroid-responsive meningitis?
6 month -2 year old large breed dogs & beagles