Cauda Equina Compression and Thoracolumbar Trauma Flashcards
The ________ is the terminal end of the spinal cord, which typically occurs at the ________ vertebral level in an adult.
The continuation of nerves fibers beyond the spinal cord is known as the ________.
conus medullaris, L1, cauda equina
List the motor, sensory and PNS Innervation of the Cauda Equina
Motor: legs, lower legs, foot and ankle, sphincters
Sensory: legs, lower legs, foot and ankle, saddle, peri-anal
PNS: bladder and distant bowel
“Keeps you Mobile and Continent”
Explain the PNS Innervation of the cauda equina (incl nerve roots)
S2-4
- Synapse for the bladder wall
- Stimulates contraction of the muscle fibres
- Relaxes the sphincters
- Controlled Micturition
How does cauda equina present?
What is the impliction of this presentation?
Combination of neuromuscular and urogenital symptoms but no such thing as a common presentation
Requires a high index of suspicion and an examination of patient
Pathophysiology of Cauda Equina Syndrome - Why is the CE at an increased risk?
Compression of the cauda equina nerve roots from ANY cause
Nerve roots at this level have a poorly developed epineurium, with relative hypovascularity in the proximal 1/3 ➞ Increased permeability from CSF support nutritional supply
This increased permiability = Increased susceptibility to pressure and more likely to become oedematous
Give the Aetiology of Cauda Equina syndrome
Frequency: CES is uncommon, both atraumatically as well as traumatically.
Mortality/Morbidity: CES is not fatal. Morbidity is variable, depending on the etiology of the syndrome.
Race: No predilection exists on the basis of race.
Sex: No predilection exists on the basis of sex.
Age: Traumatic CES is not age specific. Atraumatic CES occurs primarily in adults
Give 4 causes of CES
- Ruptured Disc (most common)
- Stenosis (narrowing)
- Tumour
- Infection
- Fracture / Trauma
- Narrowing
- Others (congenital, vascular)
What is seen on the image below
Disc Prolapse - common cause of CES
Give 4 differential diagnosis for CES
- Back Pain, Mechanical
- Guillain-Barré Syndrome
- Lumbar (Intervertebral) Disc Disorders
- Neoplasms
- Spinal Cord Infections
- Spinal Cord Injuries
Diagnosis of of CES requires neuromuscular and urogenital symptoms, list 4 of these
- lower limb weakness
- sensory changes/numbness in lower limbs or saddle area
- back pain (with or without sciatic type pains)
- dysfunction of bladder, bowel or sexual nature
- bilateral symptoms
- areflexia
Revise slide
What examination must we do if CES is suspected?
Rectal exam (PR) ➞ assess tone, peri-anal sensation, “squeeze”, etc…
Why is it important to know whether a patient has urinary retention in CES?
The outcome is very different
CES-R(etention) has a poorer outcome than CES-I(ncomplete)
How may we assess alteration in bladder function in a patient suspected of CES
May be assessed empirically by obtaining urine via catheterization.
A significant volume with little or no urge to void, or as a post-void residual, may indicate bladder dysfunction
Give 4 symptoms of CES
- Back pain, especially of new onset
- Weakness in the legs, unable to rise from a chair
- Unable to walk
- Numbness
- Loss of sexual sensation
Give 3 investigations used to diagnose CES
1. MRI – gold standard ➞ urgent if clinical suspicion
- Plain Radiograph ➞ destructive lesions
- CT +/- Contrast (Myelogram) ➞ If unable to have MRI
What is the treatment for CES
Surgical management is the primary treatment
Commonly a laminectomy or laminotomy and disc removal ➞ aims to relieve pressure of neural structures (decompresses cauda equina)
Give the Prognosis of CES with the following:
- Bilateral vs unilateral sciatica
- Perineal anesthesia
- Bilateral sciatica ➞ less favorable prognosis than persons with unilateral pain
- Complete perineal anesthesia ➞ more likely to have permanent paralysis of the bladder
Extent of perineal or saddle sensory deficit is the most important predictor of recovery!
What is the 3 column theory of spinal stability in trauma
The vertebral column is divided into 3 vertical parallel columns
Instability occurs when injuries affect 2 contiguous columns (eg. anterior and middle or middle posterior column).
Obviously a 3 column injury is also unstable
In trauma, a high index of suspicion of fracture is required if any of what 6 things are present?
- Spinal tenderness
- Ankylosing spondylitis
- Displaced sternal fracture, aortic rupture
- Multiple rib fractures
- Another spinal injury
- Calcaneal fracture
List the 4 types of thoracolumbar fractures
Incl the mechanism of injury for each
- Compression ➞ anterior wedge (lateral)
- Burst Fracture ➞ axial compression force
- Chance fracture ➞ seat belt injuries
- Fracture dislocation ➞ various forces (flexion, rotation, AP or PA shear)
Explain the patho of a compression (wedge) fracture + what is seen on an X-ray
Anterior column fails
Middle column intact – posterior part of the vertebral body is intact
Anterior wedging on the lateral view (lateral wedging on the AP view if lateral flexion)
Explain the patho of a burst fracture + what is seen on an X-ray
Involves anterior and middle column by axial compression force
AP view
- vertical fracture of the lamina
- widening of the inter-pedicular distance
- disruption/splaying of the facet joints
Lateral view
- majority involve the superior end plate
- decreased height posterior part of vertebral body
- fragments often retropulsed into spinal canal
Explain the patho of a Chance fracture + what is seen on an X-ray
Failure of the posterior and middle columns by flexion ➞ anterior column acts as a hinge and may also fail
X-Ray findings
- horizontal split of the transverse processes and pedicles
- horizontal fracture of the spinous process
- Increased inter-spinous distance
Axial CT may not provide additional information as the horizontal split is in the axial plane
