Spinal Cord Injury Flashcards
1
Q
spinal nerves responsible for the upper limbs?
A
- C5-deltoid
- C6- wrist extensors
- C7- elbow extensors
- C8- long finger flexor
- T1- small hand muscles
2
Q
spinal nerves responsible for the lower limbs?
A
- L2- Hip flexors
- L3, L4- knee extensors
- L4,L5-S1: knee flexion
- L5- ankle dorsiflexion
- S1- ankle plantar flexion
3
Q
deep tendon cutaneous reflexes?
A
- triceps C7,C8
- Biceps C5,C6
- Brachioradialis C6, C7
- patellar (knee jerk) L3,L4
- achilles (ankle jerk) S1, S2
4
Q
What are the two types of injuries to the spinal cord?
A
- Non-hemorrhagic with only high signal on MRI due to edema
- Hemorrhagic with areas of low intensity within the area of edema
5
Q
what is a primary mechanism of SCI? examples?
A
immediate effect of trauma to force and direction
- initial crush, shear, impingement, penetration, transection or hemisection, compression, contusion
6
Q
what is a secondary mechanism of SCI?
A
Neuro deterioration over minutes to hours; due to ischemia or hypoxia
- vascular insufficiency (hypotension, neurogenic shock)
- inflammation/edema (compresison injury, pinches off bloodflow–>ischemia)
- disturbance in ion homeostasis
- cytotoxicity (excessive glutamate release and neuronal excitotoxicity)
- free radical toxicity
- apoptosis
- necrosis
7
Q
SCI pathophysiology?
A
- most of the damge to the spinal cord is due to the secondary injury that takes place in the minutes and hours following injury and leads to demyelination
- immediate injury causes small microhemorrhages that enlarge (particularly in gray matter)
- may be reversible within 4-6 hours- infarction of white matter
- within 8 hours- global infarction of gray matter at the level of injury- irreversible
8
Q
- 1st priority
- acute respiratory failure is leading cause of death in high cervical injuries
- decision to intubate
- high concentration of O2 may prevent bradycardia or asystole with neurogenic shock
- if bradycardic, atropine or pace
- hypoxia- adverse effect on neuro outcome
A
airway
9
Q
- lesions above C5 level will cause partial to complete diaphragmatic paralysis
- any lesion above T12 may cause airway compromise
- lesions at c5 and below will allow full diaphragmatic movement, but intercostal muscles and abdominal muscles are affected
A
breathing
10
Q
- pts. become pikliothermic (body temp changes with temp of environment
- loss of ability to regulate core temp through vasodilation and vasoconstriction
- pt. can become dangerously hyperthermic or hypothermic
A
exposure
11
Q
- given within 8 hours of injury- some recoverable function
- may inhibit some specific levels of the inflammatory cascade- e.g, decreased edema, prevent K+ depletion
A
solumedrol
steroid protocol should initiated within 8 hours
12
Q
- transient loss of all neuroloigical function (motor, sensory and autonmic) below the injury level
- flaccid paralysis followed by spastic paresis
- loss of reflexes below SCI, but later recover
- concssion of the spinal cord
- occurs immediately-lasts several days/weeks
- physiologic response; d/t potassium loss from damaged cells
- bowel & bladder involved; priapism
A
spinal shock
13
Q
- high cervical and thoracic cord (above T6) injury can result in this
- disruption of sympathetic outflow from T1-L2
- typically seen 4-6 hrs after injury with cord lesions above T6
- can last 48hrs- several days
- pathophys: loss of sympathetic outflow with unopposed vagal activity- loss of vasomotor tone (peripheral pooling of blood and decreased preload)
-hypotension
-bradycardia (loss of sympathetic tone): tx: atropine
-hypothermia d/t loss of thermoregulation
tx: fluid resuscitation and vasopressors; cautious to avoid overload
A
Neurogenic shock
14
Q
- life-threatening: usually with lesions above T6, and occurs as a later complication, but can happen acutely
- SBP rises above 250mmHg, tachycardia, urticaria, flushing, diaphoresis, reflex bradycardia, throbbing HA
- can lead to seizures or stroke
- find the treat the problem
- nociceptive input below injury level usually d/t visceral distension (bladder distention, UTI, fecal impaction, skin lesions)
A
Autonomic hyperreflexia (medical emergency)
15
Q
ASIA impairment scale
A
- A= complete: no motor or sensory function is preserved in the sacral segments S4-S5
- B= Incomplete: sensory, but not motor, fxn is preserved below the neurological level and includes sacral segmens S4-S5 (sacral sparing)
- C= incomplete: motor fxn is preserved below the neurlogical level and more than half of key muscles below the neurological level have a muscle grade less than 3
- D= incomplete: motor fxn is preserved below the neurolgoical level and at least half of key muscles below the neurological level have muscle grade 3 or more
- E: normal: motor and sensory function are normal
