Spine And Cord Flashcards
What are the high risk factors for spinal cord injury
Over 65
Dangerous mechanism of injury
Parasthesia of the upper or lower limbs
What are the low risk factors for a c-spine injury allowing for ROM testing
No midline spinal tenderness
Ambulatory at any point
Sitting comfortably
Simple rear ended
What does in line immobilisation involve
Collar, scoop, headblocks
What happens to bladder function with a lesion above T12
Empties as it fills
You have afferent fibres to the brain so no conscious awareness of filling and have lost descending control over the urethral sphincter meaning it is constantly relaxed
Spinal reflex is still intact though: stretch transmitted by sensory afferent to synapse of interneurones which synapse of pelvic nerve and cause detrusor contraction
What happens to the bladder with a lesion below T12
Parasympathetic outflow is damaged so no spinal reflex and a paralysed detrusor muscle
Bladder fills, distends and there is overflow incontinence
What is spinal shock?
Muscle flaccidity and diminished reflexes below the level of spinal cord injury lasting1-3 days
What is the cause of priapism
Abrupt loss of sympathetics and unopposed parasympathetics leads to uncontrolled blood flow into the penile sinusoids
Why do UMN lesions lead to spastic paralysis
Lost the many descending inhibitory pathways as well as any voluntary input from corticospinal however still have the reflex arc which is excitatory
What is neurogenic shock
Type of distributive shock due to a lesion above T6.
No output to adrenal glands so no adrenaline.
Loss of sympathetic drive and unopposed vagal activity.
Hypotension + bradycardia + peripheral vasodilation
What is sacral sparing
Some degree of sensation preserved in the sacral dermatomes (even if higher dermatomes are more impaired) is associated with a better outcome
Where do spinal EDH most commonly occur
Cervical region ad anteriorly
What are risk factors for spinal EDH
Burst or compression fracture
Anticoagulated
Spinal spondylosis
Where does the bleeding come from in spinal EDH
Venous (lots of valveless anastamoses)
How does spinal EDH present
Compressive myelopathy
How does cauda equina present
Back pain Lower limb motor weakness Saddle parasthesia Urinary retention Bowel incontinence
What needs to be given to warfarinised patients with INR >2
Prothrombin complex concentrate
What is a facet dislocation
Anterior displacement of one vertebrae on the underlying one
Why do facet dislocations most often occur in the c-spine
The orientation of the facet joints here is far more horizontal than further down the spine where they are more vertical which would make a “jump” harder
C5/C6 is the most common as it’s the junction of mobile to immobile so carries increased strain
What might be damaged in facet dislocations
PLL
Vertebral arteries
Which tracts decussate at the level, which at the medulla and which don’t
At the level: spinothalamic
At the medulla: DCML, corticospinal
Don’t: spinocerebellar
How does Brown Sequrd present
Ipsilateral spastic paralysis and loss of DCML
Contralateral loss of spinothalamic
What can cause anterior cord syndrome and how does it present
ASA thromboembolism, retropulsion of bony fragments
Bilateral loss of motor function and spinothalamics
What can cause posterior cord syndrome and how does it present
PSA damage, B12 deficiency, spinal stenosis
Bilateral loss of DCML
What causes central cord syndrome and how would it present
Hyper-extension injury with inward buckling of ligamentum flavum
Spondylosis (ligamentum flavum compresses)
Cape like distribution of motor and spinothalamic loss
Motor >sensory and arm>leg
Where do spinal fractures most commonly occur and why
Junction of C-T and T-L because this is the junction of immobile to mobile
What can a fracture of the pars interarticularis lead to
Body slipping forward and compressing the cord
Where do pars interarticularis fractures most commonly occur
L4 and L5
What happens in a C1 Jefferson/burst fracture
Axial loading leads to occipital condyles being driven into C1. There are 4 breaks, 2 in the anterior arch and 2 in the posterior arch
When is a C1 Jefferson/burst fracture associated with spinal cord injury
If there is also rupture of the transverse ligament or if there is retropulsion of bony fragments
How should a C1 Jefferson/burst fracture be managed
Continue allowing them to hold their head
What is the outcome of a atlanto-occipital dissociation
Often fatal due to brainstem destruction leading to apnoea
What are the types of ondontoid/peg/dens fractures
- Tip of the peg
- Base of the peg below the transverse ligament
- Base of the peg extending into the body
Which type of peg fracture is the most common and which is the most unstable
2
What 3 views are needed to diagnose a peg fracture
AP, lateral and open mouth
Aside from radiographs, what other imaging is needed with high cervical trauma
CTA!! Both the vertebral and carotids are at risk of dissection, thrombosis and spasm with the potential of causing stroke
What happens in a hangman’s fracture
Bilateral pars interarticularis fracture of C2 leading to sponylolisthesis of C2 on C3 (C2 slips forward)
What are the forces involved in a Hangman’s fracture
Neck extension + axial load + distraction (i.e high impact under the chin)
This can be followed by secondary flexion which tears the PLL increasing instability
What injury pattern is see with a Hangman’s fracture
There is expansion of the spinal canal so often good survival
What injuries can be seen following hangings
Pulmonary oedema (neurogenic due to sympathetic drive and also due to negative inspiratory pressures)
Cricoid, hyoid and larynx damage and swelling- airway obstruction
Cardiac arrhythmias due to stimulated vagus nerve inhibiting the SA node causing ventricular escape rhythms
Carotid artery dissection
How should a patient found hanging be managed
Manually support them, maintain c-spine immobility, cut the cord, lower to the ground
Describe a typical anterior wedge fracture (patient, force, fracture appearance)
Often in osteoporotic elderly people
Axial loading in flexion
Anterior portion of the vertebra is shorter than the posterior
Describe a typical thoracolumbar burst fracture (patient, force, fracture appearance)
Patient landing on feet giving vertical axial loading
Vertebrae loses height at the front and back and there can be retropulsion of bony fragments into canal
Describe a typical thoracolumbar chance fracture (patient, force, fracture description, associated injuries)
Lap belt
Flexion about an axis that is anterior to the vertebral body leads to compression of the anterior column and distraction/opening up at the posterior
CT them because retrperitoneal duodenum can become compressed leading to bleeding/peritonitis
What forces could cause a thoracolumbar fracture dislocation
Extreme flexion
You see a transverse process fracture of L4/L5 on imaging, what should this make you suspect
Pelvic or sacral fracture
What are the types of sacral fracture
1 - lateral to neural foramina
2 - involve foramina but not canal
3 - medial to the foramina involving the canal
How would a sacral fracture present
Lower limb deficit, urinary, bowel and sexual dysfunction, S2-5 sensory loss
What is spondylolysis
Stress fracture of the pars interarticularis of L5 due to repetitive hyperextension
What can spondylolysis progress too
Spondylolisthesis (vertebrae slip out of place)
What is the progression of osteoporosis
- Loss of horizontal trabeculae resulting in prominent vertical striation
- Striated pattern lost all together leading to radiolucency
- Collapsed bodies become wedge shape and bioconcave leading to exhagerated thoracic kyphosis
What are some causes of spinal stenosis
Osteoarthritis - bony spurs and synovial cysts
Sponylolisthesis
Disc bulging
Thickened ligaments
How does a spinal cord injury causing spinal shock affect breathing
Flaccid paralysis of intercostals and abdominal muscles leads to paradoxical movements of ribs depressing inwards on inspiration
Relate spinal cord injury levels to the ability of the diaphragm and intercostal muscles to work
C3 - neither work so ventilator dependant
C4/5 - weak diaphragm so ventilator may be needed
C6/8 - diaphragm working but weak intercostals so can breathe but weak cough and sneeze
