Prolapsed Disc and Spinal Stenosis Flashcards
What type of joints are intervertebral discs
Secondary cartilaginous
What are the components of intervertebral discs
Annulus fibrosus
Nucleus pulposus
What happens to the components of a IV disc in prolapse
The annulus fibrosis can tear and the nucleus pulpous can prolapse out of the disc and result in compression of the spinal cord
What sorts of movements do IV discs resist and in what movements do they fail
Resist - rotational
Fail - with twisting
Which direction do discs usually prolapse
Postero-lateral
What is the normal ageing process of IV discs
Decreased water content
Disc scape narrowing
Degenerative changes seen on x-ray
Degenerative changes seen on facet joints
Presentation of nerve root pain
Limb pain worse than back pain
Nerve root tension signs
Nerve root compression signs
Pain in a nerve distribution
Management of nerve root pain
Most settle after 12 weeks
Physio and strong analgesia
Refer for MRI if not settled after 12 weeks
What are the 4 stages of a prolapsed disc
Bulge - common, mostly asymptomatic
Protrusion - annulus fibrosus is weak but still intact
Extrusion - nucleus pulposus herniates through annulus
Sequestration - disc material migrates and is free in canal
At what vertebral level do central disc prolapses most often occur
C5/6
What symptoms and signs does cervical disc prolapse cause
Spinal cord compression Posterolateral - stiff neck - pain radiating to arm - weakness of muscles affected by nerve root - depressed reflexes
Where do most thoracic disc prolapses occur
T11/12
Where do disc prolapses most commonly occur
Lumbar
- L4/5
- L5/S1
- L3/4
Why are posterolateral disc prolapses more common
Posterior longitudinal ligament is weakest
What may a central lumbar disc protrusion cause
Pain in both legs, or just back pain
Compressed roots within the cauda equine
What may a lateral lumbar disc protrusion cause
Compression of the nerve root
What nerve root is affected by a L5/S1 disc protrusion
- what is the sensory loss
- what is the motor weakness
- what is the reflex change
- S1
- Little toe and sole of foot
- Weak foot plantar flexion
- Ankle jerk
What nerve root is affected by a L4/5 disc protrusion
- what is the sensory loss
- what is the motor weakness
- what is the reflex change
- L5
- Great toe + 1st dorsal web space
- EHL weak
- no reflex change
What nerve root is affected by a L3/4 disc protrusion
- what is the sensory loss
- what is the motor weakness
- what is the reflex change
- L4
- Medial aspect of lower leg
- Quads
- Knee jerk
Rx of lumbar disc protrusion
Brief rest and early mobilisation
Pain relief
What is the clinical presentation of cauda equina syndrome
Bilateral sciatica
Saddle anaesthesia
Bladder or bowel dysfunction
Injury or precipitating event
Loss of anal tone and reflex
Aetiology of cauda equina syndrome
Central lumbar disc prolapse (commonest) Tumours Trauma - #, spinal stenosis Infection - epidural abscess Iatrogenic - spinal surgery, epidural
What investigations would you do for suspected cauda equina
Admission
PR exam
URGENT MRI
Lumbar CT pyelogram if MRI CI
Management of cauda equina syndrome
Emergency discectomy within 48h of onset
What can delayed treatment of cauda equina syndrome result in
The sacral nerve roots are compressed and can result in permanent bladder and anal sphincter dysfunction and incontinence
What percentage of those undergoing discectomy for cauda equina syndrome do not regain normal urinary function
30%
What percentage of those with motor deficits with CE do not regain full power
25%
What percentage of those with sensory deficits with CE do not regain normal sensation
33%
What percentage of those with perianal paraesthesiae with CE do not return to normal
25%
What percentage of those with CE have persistent sexual dysfunction
26%
What is spondylosis
A broad term meaning degeneration of the spinal column from any cause
What can occur in severe spondylosis
Can compress the whole cord, not just the nerve roots, causing myelopathy and UMN signs in limbs (increased tone, brisk reflexes)
What are the ligaments of the spine
Anterior Longitudinal - along the front of the vertebral bodies, broad and strong
Posterior Longitudinal - along the backs of the vertebral bodies (in front of spinal canal) - narrow
Ligament Flavum - between laminae
Interspinous and Supraspinous - between spinous processes
Intertransverse Ligament - between transverse processes
Where on the disc does lumbar spondylosis occur
OA of facet and disc joints with degeneration of ligaments
How can spinal claudication be distinguished from vascular claudication
- Usually bilateral
- Sensory dysaesthesiae
- Poss. weakness - foot drop
- Takes several mins to ease after stopping walking
- Worse walking down hills because the spinal canal becomes smaller in extension, better when walking uphill or riding bicycle
Treatment of lateral recess spinal stenosis
Non-operative
Nerve root injection
Epidural injection
Surgery
Treatment of central spinal stenosis
Canal shape important
Non-op
Epidural steroid injection
Surgery
Treatment of foraminal spinal stenosis
Non-op
Nerve root injection
Epidural injection
Surgery
What is spondylolysis
A crack or stress fracture develops through the pars interarticularis
What is the pars interarticularis
A small, thin portion of the vertebra connecting the upper and lower facet joints
Where does spondylolysis most commonly occur
L5 then L4
Why do fractures occur through the pars interarticularis
It is the weakest point of the vertebra, and so the most vulnerable to injury from repetitive stress and overuse
What is spondylolisthesis
Where spondylolysis is left untreated and the pars interarticularis separates and weakens the vertebra so that it shifts or slips forward on the vertebra directly below it
Symptoms of spondylolisthesis
Varying
Lower back pain
Treatment of spondylolisthesis
Depends on symptoms
- conservative with lifestyle changes
- surgery for persistent pain with nerve root entrapment
