Spinal Cord Injury Flashcards
Define spinal cord injury
- A sudden traumatic injury that either results in a bruise, partial injury or a complete injury to the spinal cord
- Can occur at any level of the spine
- Leading cause of paralysis and always results in a physical disability
Causes of spinal cord injury
Trauma > MVC, falls, violence (gunshot wounds), sports/recreation-related accidents, assault
Non-traumatic > degenerative disease, vertebral #, tumors, infections, etc.
The spinal cord provides ________ between the brain and PNS
2 way communication
Describe the matter of the spinal cord
H-shaped gray matter (neuron cell bodies) is surrounded by white matter (myelinated axons)
> Opposite to brain (white is inside in brain, gray on outside)
White matter contains:
White matter has
* ascending (sensory/afferent)
* descending (motor/efferent) tracts
Myelination = communication
Describe the composition of a spinal nerve
Each spinal nerve has a posterior and an anterior branch
- Posterior/dorsal: carries sensory perception information to the cord (afferent pathway)
- Anterior/ventral: transmits motor impulses to the peripheral target cells (efferent pathway)
How many spinal nerves are there + list their divisions
31 pairs of spinal nerves exiting the spinal cord below correlating vertebrae
- C1-C8: 8 cervical nerves, 7 vertebrae – most prone to injury due to increased ROM; C5 most common for quad
- T1-T12: 12 thoracic nerves and vertebrae– T12/L1 most common for para
- L1-L5: 5 lumbar nerves and vertebrae
- S1-S5: 5 sacral nerves and vertebrae
- 1 coccygeal nerve and vertebrae
What portion of the vertebral canal does the spinal cord span?
Upper 2/3 of vertebral canal; doesn’t span whole length of spine
- Usually ends at L1-L2 in adults
- Cauda equina: sack of nerve roots (nerves that leave the spinal cord between spaces in the bones of the spine to connect to other parts of the body) at the lower end of the spinal cord. These nerve roots provide the ability to move and feel sensation in the legs and the bladder.
Describe the respiratory innervation responsible for inhalation
C3-C5: diaphragm
C2-C7: accessory muscles - sternocleidomastoid, scalene, upper trapezius
T1-11: external intercostals
Describe the respiratory innervation responsible for exhalation
T1-11: internal intercostals
T6-12: abdominal muscles
Hyperflexion MOI
Forward, head on vehicle motor collision, whiplash
Hyperextension MOI
Backward, vehicle collisions from behind, falls
Axial loading MOI
(vertical compression)
Diving into shallow water, falling straight on butt
Rotational MOI
Laterally
Penetrating MOI
Enters spinal area; direct injury
Tetraplegia
Complete or partial loss of sensation and/or movement in all 4 extremities and torso
Cervical and upper thoracic injuries
Injury to C1-T1
Paraplegia
Complete or partial loss of sensation and/or movement in the legs (often also includes torso)
Lower thoracic & lumbosacral injuries/lesions
Injury to T2-T12
Describe the 2 ways level of injury is assessed:
- Vertebral (anatomic) level of injury: where the injury occurred
- Neurological level of injury: lowest level with intact motor and sensory function
> Usually the same, but not always: secondary injury causing ischemia/inflammation to areas higher up in the cord
Complete vs Incomplete SCI
Complete:
- Spinal cord damaged in a way that eliminates all innervation below the level of the injury
- Loss of all voluntary motor and sensory function below the level of injury
Incomplete:
- Allow some function or movement below the level of the injury.
- More common than complete injuries
- Usually still present as complete at time of injury due to swelling/inflammation. As it subsides, ability to classify increases.
Primary vs Secondary Injury SCI
Primary
- neurological damage that occurs at impact
- The immediate mechanical damage to the cord and/or vertebrae
- Solid structures crack; hollow structures pop; fixed points tear
Secondary
- worsens the primary injury, may result in death. A result of vascular injury to the cord
> Ischemia- control spinal shock
> Inflammation (local edema to the cord)
> Hemorrhage
> Impaired tissue perfusion (neurogenic shock)
> hypovolemia
Describe the Primary Survey in SCI
Done with all trauma patients
1. Airway, Alertness, C-Spine
* C-spine immobilization
* Early intubation & ventilation
* Concurrent trauma putting patient at risk for airway compromise
2. Breathing, Ventilation
* BVM or ventilator
3. Circulation and Control of Hemorrhage
* Hemodynamic instability> shock
4. Disability
* GCS < 8 = intubate
5. Environment and Exposure
* Other injuries
* Temperature management
4 Devices used for C-Spine Immobilization
- C-collar: what patient is brought in with; put on at scene
- Philly collar: unsure if injury present; more comfortable, can be sized to patient
- Vista Collar: confirmed injury; provided by OT
- Halo Device: skeletal traction with burr holes - injuries that required surgical intervention/unstable fractures – pin-site care important for infection rx
> Backboards no longer best practice
Describe the Secondary Survey in SCI
- Get adjuncts & give comfort
* CT scan: identification of injury
* ABG: impact on physical ventilation
* Continuous oximetry and etCO2
* Cardiac monitor: for additional trauma - History: What might you want to know?
* PMH, MOI, immediate symptoms post-injury (how does it differ from presentation now), treatment that has occurred, when was spine mobilized - Head-to-toe
Describe the head to toe done in the secondary survey of patient with SCI
- Mobility and sensation
* muscle weakness
* loss of voluntary muscle movement in chest, arms or legs
* loss of sensation in chest, arms or legs - Deep tendon reflexes
* biceps- C5; triceps- C7; patella- L3; ankle- S1 - Cardiopulmonary
* Sympathetic nerve impairment = cardio
* C3-C5 = diaphragmatic innervation - GI/GU
* Paralytic ileus: secondary to spinal shock; gastric mobility can return following return
Bicep reflex shows ____ innervation
C5
Tricep reflex shows _____ innervation
C7
Patellar reflex shows ________ innervation
L3
Ankle reflex shows _____ innervation
S1
Dermatome vs Myotome
Dermatome: area of skin in which sensory nerves derive from a single spinal nerve root – afferent/dorsal
Myotome: set of muscles innervated by a spinal nerve – efferent/anterior
Explain process of logroll
- 4 people minimum
- Leader at patient’s head maintains cervical stabilization and team direction
- 2 people on one side of patient; support torso, hips, and lower extremities
- Maintain vertebral column alignment during turning
- Avoid rolling onto side of injured extremities
- Logroll away from examiner
Priorities for SCI in first 24 hours
- ABCs
- Stabilize: manage damage to the spinal cord
- Prevent secondary injuries
* Control ischemia: leads to further necrosis and injury
* Inflammation: control with corticosteroids
* Manage shock (spinal, neurogenic, etc.)
* Maintain MAP 85 for spinal perfusion
Long term priorities for SCI
- Maximize potential for neurological recovery
- Prevent/minimize complications
- Regain life skills and independence
Prevention of respiratory complications
Monitor respiratory status
* Airway
* Respiratory drive
* Ventilation
* Ability to cough
* Pulse oximetry
* ABGs
Above C5: diaphragm innervation
Why are cervical and high thoracic SCI at risk for cardiovascular complications
T1-T5 innervate the autonomic nervous system
If effected - SNS response not regulated leading to impaired vessel control (dilation/constriction)
PNS intact leading to low resting responses (AD and orthostatic hypotension)
What cardiovascular complications are SCI patients at risk for?
- Impaired Cardiac Output
> Orthostatic hypotension
> Blood pooling - Clots
>VTE prophylaxis anticoagulants
> Anti-embolic stockings
> Abdominal binders: promote venous return when up in chair
> Muscles not engaged; belly protrudes
> Promotes blood return - Shock
- Autonomic Dysreflexia
Precipitating Injury for Neurogenic Shock
High thoracic or cervical cord (T6 or higher)
Pathophysiology of Neurogenic shock
Temporary loss of vasomotor tone and sympathetic innervation (= massive vasodilation)
Systemic
Duration of neurogenic shock
Temporary (often <72hrs)
Signs and Symptoms of Neurogenic Shock
Decreased CO:
- Hypotension
- Bradycardia
- Loss of ability to sweat below level of injury (= warm dry skin)
Treatment of neurogenic shock
Support airway; fluids; vasopressors; atropine; keep warm
Precipitating injury for spinal shock
SCI at any level
Pathophysiology of spinal shock
Transient loss of reflex and muscle tone (flaccidity) result of secondary injury
Below the level of injury
Duration of spinal shock
Occurs relatively immediately after injury
Variable duration (usually <48hrs- several weeks one edema decreases)
Signs and symptoms of spinal shock
Below level of injury:
Flaccidity
Loss of reflexes
Loss of sensation
Bowel & bladder dysfunction
Treatment of spinal shock
Supportive care
Autonomic dyreflexia occurs in injuries:
Occurs in T6 SCI and above
Autonomic dysreflexia is a result of
hyperactive reflex to stimulus (visceral or cutaneous) below the level of the lesion
* Bladder distention, UTI
* Bowel distention, constipation/impaction
* Skin stimulation (heat, sunburn)
* Labor
* Sexual activity
* Contact with hard/sharp object
What occurs above and below the level of the SCI in autonomic dysreflexia?
Stimulus sends signal activating SNS (increase BP)
BELOW: dysregulated SNS response resulting in massive vasoconstriction
INCREASE BP
ABOVE: PNS responds (Neuronally intact) to increased BP
BRADYCARDIA w MASSIVE VASODILATION
Bowel + Bladder Management upper vs lower SCI
Upper SCI = spastic bowel and bladder
> Voiding patterns may be uncontrollable
> Long-term indwelling/external catheters
> Rectal suppositories to promote regular bowel elimination
Lower SCI = flaccid bowel and bladder
> Intermittent urinary catheterization
> Manual pressure over bladder
> Bowel disimpaction regularly
Male sexual function SCI
- Erectile dysfunction (75%)
- Reflex erections direct stimulation independent of erotic stimuli
- Preserved with injury above L2
- Ejaculation problems (95%)
- Requires parasympathetic, sympathetic, and somatic neural components
- Risk of autonomic dysreflexia
Female sexual function SCI
- Orgasm is possible
- Decreased lubrication produced
- Pregnancy is possible (rates similar to non-injured population)
- Risk of autonomic dysreflexia
- Menstrual periods usually stop due to the shock from the injury; usually start in 3-6 months
