SA Med - Neuro - Spinal Cord Injury

drraythe's version from 2017-09-19 01:51

SCI = Spinal cord injury. IVDD = Intervertebral Disk Dz - INTRO + TYPE I

Question Answer
2 ways to think about SC injury?(1) Painful vs non-painful
(2) Progression: acute vs chronic, progressive vs non-progressive.
On your DAMNIT-V list, which czs (letters) can you toss out when considering SC injury?Toss out metabolic, nutritional, & idiopathic czs
3 examples of conditions considered primary SC injury?Intervertebral disk Dz
Vertebral column trauma
Fibrocartilaginous embolism
On the DAMNIT-V scheme, what is IVDD (intervertebral disk Dz) considered?DEGENERATIVE (both type 1 & 2)
What is Hansen type 1 IVDD? Type 2? (Versus synopsis)TYPE I: young chondrodystrophic dogs, early in life disk EXTRUSION. TYPE II: chronic, progressive, old dogs, PROTRUSION of disk
What is the possible Type III IVDD?Acute non-compressive nucleus pulposus extrusion
What are the 2 parts of the intervertebral disk? (anat)nucleus pulposus is the inside squishy shock absorption part. annulus fibrosis is the fibrous part around the nucleus to hold it together
What is the signalment of a TYPE I IVDD?Young to middle-aged chondrodystrophic dogs-- think DACHSHUND!!! Also beagle, French bulldog, Pekingese... (other small breeds: Lhasa apso, Jack Russell terrier, Bichon frisé, Maltese, Miniature poodle, Shih tzu .... RARE IN CATS)
Is type I IVDD 1° or 2° SCI?
Explain the pathophys of TYPE I IVDDthere is disk degeneration due to chondroid metaplasia (the disk is trying to turn itself into cartilage)- can see dehydration & mineralization. This leads to EXTRUSION of the disk material (nucleus shoots through annulus & into canal) via a tear in the annulus fibrosis, & the degenerative nucleus pulposus comes out (w/ varying force) into vertebral foramen. This leads to 1° SCI w/ compression, or concussion/contusion (type III if it just czs concussion or contusion but not compression)
What are the 2 places in the spine where there are not IV disks?C1-2 & S1-3.
Where does Type I IVDD occur? (Most commonly?)Can occur anywhere there is a IV disk EXCEPT for
(1) C1-2 & S1-3 (there are no IV disks here)
(2) Thoracic region. So can happen in cervical, lumbosacral (part of LS stenosis) but ESP THORACOLUMBAR region.
Why is IVDD not likely/does not occur in the thoracic region?Bc intercapital ligament across ribs shields the spinal canal, gives more protection
Are CSs of Type I IVDD acute or chronic? What are they? (kinda more like presentations- 6)ACUTE:
(1) Paraspinal pain only
(2) Ambulatory w/ proprioceptive ataxia & paresis
(3) Nonambulatory tetra- or paraparesis
(4) Paralysis w/ intact nociception
(5) Paralysis w/ absent superficial pain perception
(6) Paralysis w/ absent nociception
Typical case of type I IVDD localizes to where?T3-L3 (thoraco-lumbar)
CSs associated w/ IVDD are lost in a specific order, & then gained back in the same but opposite order. List them from first lost to last lost (& realize they are gained back backwards)Proprioception → ataxia → voluntary motor/voluntary urination → superficial pain → deep pain
How do you Dx IVDD type I? When do you choose to do what?(1) RADIOGRAPHS
(2) only use advanced imaging for sx planning: Myelography, Computed tomography, Magnetic resonance imaging
What will IVDD look like on radiographs?Narrow wedge shape to intervet disk space, narrowed facet space (dont be fooled by the calcification of the IV disks in other spots, that is not IVDD) (pic is at T13-L1)
When is Medical/conservative Tx of Type I IVDD a good option? What IS this Tx?Good option until motor function is lost then you must consider other options. Medical management inclds: STRICT CAGE REST for 2-6wk, +/- pain medications, muscle relaxers, acupuncture.
What things should you AVOID if you are medically managing a type I IVDD?(Remember, medical management is a good option till motor function is lost) Avoid physical therapy & chiropractic manipulation, *Avoid steroids, NSAIDs (steroids make them feel better, then the owners take them off cage rest, bad news… just avoid it). Prog good till moto fxn lost
What are 2 sx procedures you can use to Tx type I IVDD?(1) Ventral slot
(2) Hemilaminectomy
What are post-op instructions for after a type I ivdd sx? Prog of sx?(ventral slot of hemilaminectomy) Cage rest, Pain medications, muscle relaxers, acupuncture, Physical therapy, Lifestyle changes. Prog is good to excellent until deep pain is lost. (≤ 48 hr= 50% chance for return to function, > 48 hr= virtually no chance at return to function (~5%) )

TYPE 2 / 3, Fibrocartilaginous Embolism (FCE)

Question Answer
Type II IVDD signalment?Older (> 7 yr), large breed dogs (DEGENERATIVE CONDITION) (basically opposite signalment of type I, lol)
Explain the pathogenesis of type II IVDDDisk degeneration due to Fibroid metaplasia (type I was CHONDROID) as well as Concurrent degeneration of anulus fibrosus. This leads to PROTRUSION of the disk (that is to say bulging, not extrusion like in type I) due to Partial tear/weakness of dorsal anulus fibrosus... which allows for bulging of the disk
Are the CSs of type II acute or chronic? what are the CSs?CHRONIC: See Tetra- or paraparesis & proprioceptive ataxia , +/- paraspinal pain
How do you Tx Type II? (how is it the same & how does it differ though) prog?As for Type I (medical mgmt till motor loss is an option, or sx- hemilaminectomy or ventral slot) w/ surgery, can transiently or permanently become worse, CAN DO Epidural steroids. Ok for physical therapy to be a component of medical management. Prog is guarded :(
What is going on in type 3 IVDD?Same pathogenesis as Type I, but Disk ejected at extremely high velocity → Spinal cord contusion/concussion BUT No compressive material left over
How do you Tx type II differently? prog?Imaging shows lack of compression-- so there is nothing to remove in sx. So Tx As for conservative management of Type I IVDD. Prog is fair.
What is the signalment for FCE?Older, large breed dogs. Also schnauzers, shelties. RARE in cats.
Explain the pathogenesis of FCEDisk material occludes a spinal cord blood vessel → Ischemic necrosis ensues ( Many theories as to how the disk material becomes lodged in the artery(ies) ) Often associated w/ strenuous activity (just up for frisbee, yelp, & are suddenly paralyzed)
What are the CSs of FCE? (Are they acute or chronic?)ACUTE, nonprogressive onset of asymmetric paresis/plegia. Front & back = hemiparesis/hemiplegia, 1 limb = monoparesis/monoplegia. Can less commonly be bilateral. ***THEY ARE NON-PAINFUL!
How painful is FCE?NOT PAINFUL
How do you Dx FCE?Necropsy= definitive Dx. Dx often by CSs & signalment. Exclude other myelopathies (imaging, CSF tap)
Tx & PTx for SCI?Tx: Supportive care for acute SCI, Physical therapy. prog excellent, unless Large lesion on MRI or absent nociception
What is the prog of Vertebral Column Trauma?Good to fair as long as nociception is intact. Deep pain neg= grave prognosis for return of function
When does secondary SCI happen?Immediately after 1° SCI occurs.
What can we do about 2° SCI?Very little we can do to alter the course of secondary SCI- however In contrast to brain injury, steroids MAY be useful here
What is Myelomalacia/ how does this occur? (Pathogenesis)(Definition: softening of the spinal cord)
Ffatal sequel to acute
Severe SCI ( ~10% of deep pain neg PTxs)
Hemorrhagic necrosis ascends/descends from point of primary SCI leading to Morbid softening of the spinal cord
Can occur up to 2 weeks after primary injury
CSs of myelomalacia?Lower motor neuron signs develop as spinal cord tissue becomes necrotic. Clinically: Previously UMN signs become LMN (reflexes, tone), Loss of abdominal tone, Involvement of thoracic limbs, Respiratory muscle paralysis → death due to asphyxiation. IT IS PAINFUL
Tx for myelomalacia?No Tx- humane euthanasia
What is Solu-Medrol? What should you know about it w/ vet med?It's a steroid- Controversial in humans, even more so in our PTxs Only to be used w/in 8 hours of known acute, severe SCI. What makes it different than other steroids is that it is lipophilic, & Interrupts arachidonic acid cascade (Prevents lipid peroxidation). Would need a High dose regimen, not w/o severe side effects
Some things you must keep in mind for care of the recumbent PTxWell-padded bedding
Frequent rotations
Evacuate urinary bladder
Keep PTx clean & dry (look out for decubital ulcers)