4 - Spine Flashcards
Vertbrae of the spine:
7 cervical 12 thoracic 5 lumbar 5 fused sacral 4 (usually fused) coccygeal
33 total
C1 and C2 are unique; they are designed for:
Rotary motion
C2 is AKA
The axis
C1 is AKA
The atlas
Components of the vertebral arch:
Two pedicles
Two laminae
Seven processes (one spinous, two transverse, four articular)
What is the MC’ly injured region of the spine?
Cervical
Because it’s the bend-iest
Most occur at C2 or C5-C7
The spinal cord gives rise to:
31 pairs of spinal nerves:
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
Which zones of the spine sustain the greatest amount of stress during motion and are most vulnerable to injury?
The transitional zones (i.e. C7-T1)
Since the thoracic spine is more rigid thanks to its articulation with the ribcage, if your patient has injury to the thoracic spine:
It indicates that the patient was subjected to severe traumatic forces and is at high risk for intrathoracic injuries
Where does the SC turn into the cauda equina?
L1
What happens to the width of the SC as it moves from thoracic to thoracolumbar region?
It gets wider
Likelihood of an isolated lumbar spine fracture injuring the SC?
Rare
Why? Because the SC widens out and then splits into the cauda equina
Sacral fractures that involve the central sacral canal can produce:
Bowel or bladder dysfunction
A spine injury is considered unstable if:
At least 2 columns of a particular region are involved
It can be difficult to accurately identify an unstable spine injury in the setting of polytrauma, therefore:
Assume ANY spine fx is UNSTABLE and maintain APPROPRIATE precautions until expert consultation can be obtained from a spine surgeon
What are the two main types of injury that result in spinal cord damage?
- Primary injury from mechanical forces from traumatic impact
- Secondary injury (caused by primary) sets in motion a series of vascular and chemical processes that lead to secondary injury
The initial phase of SCI is characterized by:
Hemorrhage into the cord and formation of edema at the injured site and surrounding region
The secondary phase of SCI is characterized by:
Local ischemia of the cord
Cell death of the SC ensures from a combination of mechanisms including:
Electrolyte imbalances
Cell edema
Formation and release of oxidative substances
The American Spinal Injury Association defines a complete neurologic lesion as:
The absence of sensory and motor function below the level of injury
An incomplete lesion is defined as:
Sensory, motor, or both functions are partially present below the neurologic level of injury
Prognosis for complete lesions of SC?
Minimal chance of functional motor recovery
Patients in spinal shock will lose:
All reflex activities below the area of injury, and lesions cannot be deemed truly incomplete until spinal shock has resolved
The three most important spinal tracts to know:
Corticospinal (descending motor)
Spinothalamic (pain and temp sensation)
Doral (posterior) columns (vibration and proprioception)
Where do 90% of the corticospinal tract (motor) fibers decussate?
The lower medulla
Then they keep descending as the lateral corticospinal tract
Damage to the corticospinal tract neurons (upper motor neurons) in the SC results in:
Ipsilateral clinical findings such as muscle weakness, spasticity, increased DTR’s, and a (+) Babinski
The spinothalamic tract transmits:
Pain and temperature sensation
Where does the ascending sensory neuron of the spinothalamic tract decussate?
The second neuron immediately crosses the midline in the anterior portion of the spinal cord and ascends as the lateral spinothalamic tract
When the spinothalamic tract is damaged, the patient experiences:
Loss of pain and temperature sensation in the contralateral half of the body
The dorsal columns transmit:
Vibration and proprioceptive information
How do the dorsal column neurons (vibration and proprioception) differ from the pain and temperature neurons?
The dorsal column neurons do NOT immediately synapse in the spinal cord
Instead, they enter the ipsilateral dorsal column and do NOT immediately cross midline
Injury to one side of the dorsal columns will result in:
Ipsilateral loss of vibration and position sense
Light touch is not completely lost unless there is damage to both:
The spinothalamic tract
AND
The dorsal columns
The first seven spinal nerves - do they exit above or below the corresponding vertebral body?
Above
What is the spinal nerve that exits between C7 and T1 called?
C8 (even though there’s not C8 vertebral body)
Then the remaining nerves are all named for the vertebral body above it (i.e. the T4 spinal nerve root exits below T4)
Even though its utility is debated, prehospital care of suspected spine injury still requires:
Rigid C-collar and long spine board
Should my fully conscious, neurologically intact patient with a penetrating neck injury get a rigid c-collar and long spine-board immobilization?
No - these interventions can delay resuscitation and obscure neck injuries - just tell em to not move around.
Any patient with an injury at C5 or above should probably receive what intervention?
Secure the airway with an ET tube
If time allows, do a brief focused neuro exam before you knock ‘em down and tube ‘em
High cervical injuries - be alert for:
Respiratory compromise
HOTN in patients with SCI may be due to:
Neurogenic shock
Blood loss
Cardiac injury
Tension pneumo
What should you presume to be the cause of HOTN in the setting of SCI until proven otherwise?
Blood loss
Why do we remove long boards ASAP?
They’re associated with pressure sores (and also crazy uncomfortable)
Preferred method for getting patient off a long board?
Log-roll
You can check the back and butt while you do it
Whoever is holding the head does the count
During the history portion of the SCI exam, pay particular attention to:
Any sxs indicating present or impending respiratory compromise, including: Dyspnea Palpitations Abdominal breathing Anxiety
Physical exam for SCI should focus on:
Delineating the level of the SCI
During the PE for SCI, make sure you test for:
“Saddle anesthesia”
Sensory deficit in the region of the buttocks, perineum, and inner aspect of the thighs
“Sacral sparing” with preservation of anogenital reflexes denotes:
An incomplete spinal cord level, even if the patient has complete sensory and motor loss
How to do bulbocavernosus reflex?
Finger in butt
Squeeze penis
Should feel the anal sphincter contract
Cremasteric reflex?
Stroke the thigh
If scrotum rises, some spinal cord integrity still exists
Anal wink reflex?
Contraction of the anal musculature when the perianal region is stimulated with a pin
Indicates some sacral sparing
In the setting of SCI, the presence of priapism implies:
Overdose on Viagra . . . . . . . Or, more likely, complete SCI
Slide 37
Chart of Major Incomplete Spinal Cord Syndromes
I’ll make some cards on it
Anterior cord syndrome results from damage to the:
Corticospinal and spinothalamic pathways, with preservation of posterior column function
Anterior cord syndrome is manifested by:
Loss of motor function and pain and temperature sensation distal to the lesion
Only vibration, position, and tactile sensation are preserved
Overall prognosis for anterior cord syndrome?
Poor
What is affected in central cord syndrome?
The centrally located fibers of the corticospinal and spinothalamic tracts
How do central cord syndrome patients present?
Decreased strength and, to a lesser degree, decreased pain and temperature sensation, more in the upper than lower extremities
What is preserved (usually) in central cord syndrome?
Vibration and position sense
The majority of central cord syndrome patients will retain:
Control of bowels and bladder (though it may be impaired in severe cases)
What is Brown-Sequard Syndrome?
Hemisection of the cord
How does Brown-Sequard present?
Ipsilateral loss of motor function, proprioception, and vibratory sensation, and contralateral loss of pain and temperature sensation
MCC of Brown-Sequard Syndrome?
Penetrating injury
Sxs of cauda equina?
Bowel/bladder dysfunction
Decreased rectal tone
Saddle anesthesia
Variable motor and sensory loss in the lower extremities
Decreased lower extremity reflexes
Sciatica
If you suspect cuada equina, order:
A STAT lumbosacral MRI
What type of shock is neurogenic shock?
Distributive
Loss of sympathetic arterial tone -> extreme vasodilation -> pooling of blood in the distal circulation -> HOTN
If the T1 through T4 cord levels are compromised, leads to:
Loss of sympathetic innervation to the heart -> unopposed vagal parasympathetic cardiac innervation -> bradycardia (or an absence of reflex tachycardia)
In general, patients in neurogenic shock are:
Warm
Peripherally vasodilated
Hypotensive with relative bradycardia
Spinal shock is:
The temporary loss or depression of spinal reflex activity that occurs below a complete or incomplete SCI
NOT the same thing as neurogenic shock
Flaccidity, loss of reflexes, loss of voluntary movement
What are among the first reflexes to return as spinal shock resolves?
Delayed plantar
Bulbocavernosus
How long does spinal shock last?
Variable: could be days to weeks, or persists for months
Canadian C-Spine test thing
Decision point for whether they need imaging
Three questions
Must answer “yes,” to everything to get a “go”
If “no,” gotta get the imaging
SLIDE 50
NEXUS or CCR for for c-spine?
Either is fine
Three view for c-spine plain films:
AP
Lat
Odontoid
A single lat gets about 90% of injuries
The others are for insurance
Important to make sure your c-spine films have:
All seven vertebrae
Superior border of first thoracic vertebrae
What view may be necessary to visualize the cervical-thoracic junction?
Swimmers view
Main disadvantage of plain films for c-spine?
Not great for imaging C1-C2
Most trauma centers use what study for initial c-spine eval?
CT
If you see an injury to c-spine on plain films, you gotta order:
CT
So may as well just get the CT since you’re gonna have to do it anyways if you see something
Sxs of ligamentous spine injury
Persistent neck pain / midline tenderness
Extremity paresthesias
Focal neuro findings despite normal plain radiographs and/or CT
Study of choice for suspected spine ligamentous injuries?
MRI
What if no MRI available?
Reliable patients can be sent home in firm foam collar with instructions to get outpatient MRI in 3-5 days
MRI not be as good as CT for bones, but it’s superb at defining:
Neural, muscular, and soft tissue injury
Diagnostic test of choice for describing the anatomy of nerve injuries?
MRI
If pt has neuro findings with no clear explanation after plain films and CT, order:
MRI
What do you if you determine that there is a spinal column injury at one level?
Get a CT of the entire remainder of the spine
Imaging if spine in obtunded patient?
No clear consensus
Most likely, (-) CT is good enough to clear ‘em
What are the goals of txt?
Prevent secondary injury
Alleviate cord compression
Establish spinal stability
Regardless of neuro compromise, all spinal column fractures or ligamentous injuries require:
Consult from either a neurosurgeon or orthopedic surgeon, depending on the facility
Management of a “wedge” or “anterior” compression fx?
If less than 40% loss of vertebral height, may be a candidate for outpatient therapy
If over 50% or if the angle between the damaged vertebrae and the rest of the spinal column is >25% to 30%, it’s generally considered unstable
Burst fractures may result in:
Retropulsed fragments that can impinge on the spinal canal and cause neurologic injury
Its like iron man but not nearly as cool
Chance fracture
Caused by flexion-distraction mechanism and involves minor anterior vertebral compression and significant distraction of the middle and posterior ligamentous structures
Chance fx on radiograph
Transverse fx lucency in the vertebral body, increased height of the posterior vertebral body, fracture of the posterior wall of the vertebral body, posterior opening of the disk space
If you see compression fx’s of the thoracolumbar spine on plain films:
Get a CT
Txt for stable wedge fx with no neuro sxs
Analgesia Heat Massage Rest PT
Does an isolated coccyx fx need an emergent consult?
Nah
Can be dx’d clinically
Txt symptomatic, analgesics, rubber donut pillow
Slides 72-76
A BUNCH of shit about steroids - i have no idea if this is important. I’m sorry i’m at the end and i cant.
Basically, don’t use steroids to txt spinal injuries routinely.
No roids for penetrating spine injuries
Treating neurogenic shock
Normal stuff
Fluids
If that doesn’t do it, pressors
Keep SBP > 90mmHg
If they’re really brady, consider atropine
For spinal GSW’s through the belly:
Give prophylactic broad spectrum ABX
Kid: i’ll call you later
Dad: dont call me later; Call me dad
