SCI Flashcards
Most common etiology of SCIs?
Younger age groups vs. older age groups?
MVC most common overall (38%), falls 2nd (33%)
- MVC most common in younger age groups
- Falls = leading cause of SCI in pts > 65yo
Mean age of SCI?
Male : Female ratio?
Mean age 43 yo (up from 29 in the 1970s)
M:F ratio = roughly 4:1
Most common type of neurological injury? (tetra vs paraplegia, complete vs. incomplete?)
Incomplete tetraplegia
Incomplete paraplegia
Complete paraplegia
Complete tetraplegia
(tetra - para - para - tetra; incompletes come first)
Blood supply for spinal cord?
Anterior 2/3 = anterior spinal artery (derived from vertebral arteries)
Anterior distal 1/3 = artery of Adeamkiewicz (AKA great anterior radiculomedullary artery or arteria radicularis anterior magna); derived from descending aorta
Posterior cord = posterior spinal arteries
*Ischemia is more likely in watershed region b/t blood supplies (lower thoracic region)
What is a Jefferson Fracture? Typical treatment?
C1 burst fracture
due to high axial impact load -> burst fracture of anterior or posterior arches of C1 (Atlas) vertebra
Tx: cervical brace (Halo), or surgery if unstable
What type of dens/odontoid fracture is most common?
Type 2 - base of odontoid, typically requires surgery as is unstable
Dens fractures:
Type 1 = tip of dens (stable)
Type 2 = base of odontoid (typically unstable)
Type 3 = base of odontoid extending into C2 vertebrae (more stable, sometimes needs surgery)
What is a Hangman Fracture?
C2 burst fracture
Due to rapid deceleration injury of neck
Tx: cervical bracing vs. surgery if unstable
What type of SCI is usually due to hyperextension injury?
Central Cord Syndrome
E.g. elderly falling onto outstretched chin (cervical extension); inward bulging of ligamentum flavum into stenotic canal
Tx: often can treat w/ cervical collar
Most common level of cervical facet joint dislocations? (Jumped facets)
Unilateral = C5-C6
Bilateral = C5-C6
Tx: surgical stabilization often required
what is a chance fracture?
Fracture extends from spinous process through the vertebral body
Usually due to trauma/distraction injury
TX: often neurologically stable, may only require bracing (CASH/Jewett brace to limit flexion)
Criteria for ASIA B injury?
some sensory sparing below neurological level of injury w/ no motor function more than 3 levels below each motor level (S4-S5 or deep anal sensation is intact)
Criteria for ASIA C injury?
voluntary anal contraction OR some motor function is preserved below neurological level of injury
< 50% grade 3/5 strength or better
Criteria for ASIA D injury?
Voluntary anal contraction AND some motor function is preserved below neurological level of injury where > 50% of these muscles are 3/5 strength or better
Ambulation prognosis for posterior cord syndrome?
very poor
Posterior cord syndrome = rare, injury to dorsal columns, b/l impaired light touch, pressure, prioprioception
Better prognosis for recovery in Central Cord Syndrome?
Age < 50 = better prognosis
Central cord = most common incomplete SCI
UE > LE affected, distal > proximal weakness
Expected deficits in Brown Sequard Syndrome?
Ipsilateral loss of motor, coordination, light touch/proprioception
Contralateral loss of pain/temperature several levels below level of injury
Conus Medullaris Syndrom vs. Cauda Equina deficits?
Conus Medullaris = symmetric w/ variable bowel/bladder dysfunction; often NORMAL motor function (L1-L5 roots have already come off the cord, typically unaffected) -> UMN injury
Cauda Equina Syndrome = Asymmetric, variable myotome weakness and dermatome sensory loss -> LMN bowel/bladder; EMG can offer prognostic value
First reflexes to return after spinal shock?
Bulbocavernosus, anal wink, Babinski
SCI levels at risk for autonomic dysreflexia?
T6 and above
What is the cause of bradycardia in AD episodes?
Local vasoconstriction -> vagal nerve slows HR to compensate
Pharmacologic treatments for AD if SBP > 150?
Nifedipine 10mg
Clonidine 0.3mg
Nitroglycerin topical (above level of injury)
What amount of pressure leads to capillary ischemia and pressure injuries?
Pressure > 70 mmHg causes capillary ischemia to that area of skin
Most common site of pressure injury in adults?
sacrum
Most common site of pressure injury in children?
occiput
Pressure Injury stage?
Non-blanchable erythema
Stage 1
Pressure Injury stage?
Skin breakthrough that extends into the dermis?
Stage 2
Pressure Injury stage?
Extends through the dermis with subQ fat exposed
Stage 3
Pressure Injury stage?
Muscle, tendon, or bone is exposed
Stage 4
Vacuum-assisted closure is indicated for which stages of pressure injuries?
stage 3 and stage 4
What type of wound care is indicated for stage 1 and stage 2 pressure injuries?
occlusive dressings - help to maintain a moist environment
What is the role of the frontal lobe in normal bladder physiology?
Frontal lobe primary motor cortex allows voluntary contraction/relaxation of external urethral sphincter
Also inhibits the sacral micturition center (parasympathetic)
What is the role of the pontine micturation center in normal bladder physiology?
coordinates detrusor contraction with internal sphincter relaxation
What is the role of the sacral micturition center in normal bladder physiology?
allows parasympathetic micturition action
Parasympathetic Pee Pelvic
Which nerve (and corresponding roots) allows for voluntary contraction of external sphincter?
Pudendal nerve (S2-S4)
Promotes bladder storage
What is the action of the pelvic nerve on the bladder, and what receptors does it act on?
Pelvic nerve (S2-S4) = parasympathetic
Activates muscarinic ACh receptors in bladder wall to cause detrusor contraction -> causes bladder emptying
What is the action of the hypogastric nerve on the bladder, and what receptors does it act on?
Hypogastric nerve (T11-L2) = sympathetic
Activates α-1 (internal urethral sphincter) and β-2 receptors (bladder wall) to promote urine storage
“Hypogastric nerve makes your bladder as big as a hippo”
Most common bladder pathology in SCI?
detrusor-sphincter dyssynergia
Impaired coordination of sphincters and detrusor contraction -> high vesicular pressures, vesicoureteral reflux (VUR) = complication
Goal UOP volumes for clean intermittent cathing?
< 500cc
What are the motor and sensory plexuses for the bowel?
Myenteric (Auerbach) plexus = motor plexus
Submucosal (Meissner) plexus = sensory plexus
Coordinate peristalsis
Normal bowel physiology (parasympathetic/sympathetic actions, somatic control of sphincters)?
Parsympathetic (vagus and pelvic nerves) action is to digest - peristalsis
Sympathetic (hypogastric nerve) action is to store (internal anal sphincter contraction) and shunt blood away from bowel
Somatic (pudendal nerve) control over external anal sphincter
What is the gastrocolic reflex?
Presence of food in stomach causes reflex defecation (sit pt on commode 15-60min after meal for bowel program)
What is the rectocolic reflex?
Rectal distension causes reflex defection
Utilize digital simulation in bowel program
Female SCI - effects on fertility?
Fertility unaffected
Menstrual cycle returns to normal within 6-12 months after SCI
Male SCI - effects on fertility?
Poor semen quality and impaired erections cause decreased male fertility after SCI
Treatment of hypercalcemia in SCI?
IVF (normal saline) - increases urinary excretion of calcium
Pamidronate (bisphosphonate) - inhibits osteoclast-mediated resorption, reduces osteoclast viability; administered as single IV infusion, rapidly lowers serum calcium within 3 days
Furosemide increases urinary excretion of Ca (although not routinely used)
**Avoid thiazide diuretics - cause hypercalcemia
Most common site of fracture in SCI? Typical treatment?
Distal femur, most fractures occur while doing ADLs
Tx: frequently treated non-operatively w/ soft padded splints
Pulmonary function test patterns in SCI?
All lung volumes decreased except residual volume (restrictive lung pattern due to muscle weakness)
DVT/PT ppx recommended after SCI?
SQ heparin or LMWH until discharge (incomplete injuries) or 8-12 weeks for complete SCI; compression garments
Most common causes of death in SCI?
Respiratory complications
Acute = PE
Chronic = PNA
Medication w/ FDA approval for neuropathic pain following SCI?
Pregabalin
Most common MSK nociceptive pain in SCI patients?
Shoulder = most commonly affected joint, usually due to weight-bearing/overuse
Highest level complete SCI level that can live independently without aid of an attendant?
C6 complete tetraplegia (highly motivated)
- feeding w/ universal cuff for utensils
- Transfers require stabilization of elbow extension w/ forces transmitted from shoulder
- bowel care w/ suppository inserter or other apparatus for digi stim
*C7 level is the usual level for achieving independence
Insidious onset of ascending loss of reflexes, sensation, burning pain worse w/ sitting or valsalva in SCI patient is concerning for what complication?
Syrinx formation
MRI w/ contrast
Completion of suicide is most common in paraplegics or tetraplegics?
paraplegics
Depression is very common in SCI, increased risk of suicide
minimum strength needed for tendon transfer in SCI?
must have 4 or 5 strength in the tendon being transferred since you usually lose a grade postsurgery
