Spinal cord & root compression Flashcards
How many vertebrae are there in the spine?
24
How many spinal nerves are there? Divide them into sections
There are 30
C1 - C8
T1 - T12
L1- L5
S1 - S5
Where are the ‘enlargements’ of the spine?
Cervical enlargement
Lumbrosacral enlargement
Describe the features of spinal cord from top to bottom?
Starts at bottom of brainstem
Cervical enlargement
Lumbrosacral enlargement
Conus medullaris: the end of the spinal cord
Cauda equina: projections out of the conus medullaris
Describe the structure of a vertebra bone?
Vertebral body
Vertebral foramen posterior to this
Transverse processes go out either side of the foramen
Spinous process goes out the back
The lamina links the transverse and spinous processes together
What is the name of C1?
Atlas, carries the weight of the head
Like in mythology, atlas carrying the world
What is the name of C2?
Axis
What is sciatica?
Shooting pain from the lower back, through the buttocks and the leg that goes into the sole of the foot
What causes sciatica?
Compression of any of the 5 nerve roots that contribute to the sciatic nerves
Which spinal nerve roots contribute to the sciatic nerve?
L4 L5 S1 S2 S3
Which spinal nerve roots supply the femoral nerve?
L2 - L4
What parts of the body does the sciatic nerve contribute to?
Posterior compartment of thigh
What is the structure of the vertebral discs?
Annulus fibrosis, hard-ish capsule on outside of disc
Nucleus pulposus: soft, fills centre of disc?
What causes disc prolapse?
Degeneration due to age
Strenuous physical activity
Describe what happens when a disc prolapses?
A weakness in the annulus fibrosis, means that the disc starts to protrude towards the spinal roots
The nucleus pulposus can leak out too
This can put pressure on the spinal cord or spinal roots causing symptoms
Which discs of the spinal cord are more prone to prolapse?
Lumbar
What is a disc herniation?
The same as a disc prolapse
Clinical features or disc prolapse?
Back pain
Buttock, leg pain
Altered sensation
Motor weakness
Altered reflexes
What causes the altered sensation and motor weakness in a disc prolapse?
The prolapsed disc is pressing on the spinal nerve roots?
Causing problems with motor and sensory nerve conduction
What causes back pain in disc prolapse?
Pressing of herniated disc on the longitudinal ligament of the dura mater
A patient presents with pain from the buttocks down to the foot on his right side, he says the pain is worse on the lateral side of his foot.
On examination you find calf weakness and altered ankle reflexes.
Where is the disc prolapse?
The disc between L5 and S1 has prolapsed
The right S1 nerve root is being compressed
A patient presents with pain that radiates to his ankle and top of his foot on his left side
He has loss of sensation of the lateral side of his left leg, as well as the top of his left big toe.
Where is the disc prolapse?
The disc between L4 and L5 has prolapsed
The left L5 nerve root is being compressed
What is the sciatic stretch test?
A test that checks for damage affecting the sciatic nerve
Get the patient lying down
Lift the leg, keeping the knee straight
Move the ankle into a dorsiflexed position (so toes point back towards patient’s head) to lengthen the nerve further
If there is sciatic damage the patient will feel shooting pain, tingling, tight restricted feeling
Diagnosis of disc prolapse?
Clinical signs
Sciatic stretch test
Most cases of disc prolapse will require treatment to resolve them.
True or false?
False
90% of cases resolve on their own
How does a disc prolapse resolve without intervention?
The herniated material becomes dehydrated, and can be reabsorbed
Management of disc prolapse?
Advise rest, analgesics and NAIDs
If more severe provide physiotherapy
Local steroid injections are sometimes indicated
Advise them to come back if not resolved in 12 weeks
If not resolved:
MRI to look at herniation
Microdiscectomy
When does a disc prolapse become an emergency?
If it results in cauda equina syndrome
If there is compression on the spinal cord which results in progressive neurological deficits
What does spondylolisthesis mean?
Slippage of one vertebra out of position, either forward or back or laterally
What does spondylosis mean?
Degenerative disc disease
What does myelopathy mean?
Spinal cord disease
What does radiculopathy mean?
Spinal nerve root disease
Myelopathy VS radiculopathy?
Myelopathy = disease of spinal cord
Radiculopathy = disease of spinal nerve root
What is cauda equina syndrome?
A medical emergency!
A massive disc herniation where many nerves of the cauda equina are compressed
Does cauda equina syndrome occur acutely or chronically?
Acutely
Clinical features of cauda equina syndrome?
Impaired sphincter responses:
- problems with micturition
- post voidal incontinence
Saddle anaesthesia:
- numbness in saddle area
- decreased anal tone
Lower motor neuron signs in lower limbs:
- paralysis
- reduced reflexes
Where is the saddle area?
Perineal area
If you were riding a horse, all the areas that would touch the saddle
Diagnosis of cauda equina syndrome?
MRI or CT (MRI preferred)
Clinical signs and examination
Management of cauda equina syndrome?
Surgery ASAP, time is nerve function
Surgical decompression, remove part of disc that has herniated and is putting pressure on cauda equina
What is the difference between simple disc prolapse and spinal cord compression?
Disc prolapse = radiculopathy, compression on spinal nerve roots
Spinal cord compression = myelopathy, the compression is on the spinal cord
What are the causes of spinal cord compression?
Vertebral # caused by:
Vertebral bone tumour (myeloma) or mets
Osteoporosis
(Spinal tuberculosis)
Clinical features of spinal cord compression?
Progressive weakness of legs
Upper motor neuron pattern
Anything below where the compression is affected by motor and sensory deficit
Urinary incontinence
Why does myelopathy show an upper motor neuron pattern?
Damage is on spinal cord, which is the upper motor neuron
Why does radiculopathy show a lower motor neuron pattern?
Because the spinal nerve roots are lower motor neurons
Investigations of spinal cord compression?
Clinical signs
MRI
X-ray may show up any cancer
Management of spinal cord compression?
Emergency surgery to decompress spine
Delay can lead to irreversible paraplegia
Radiotherapy if not suitable for surgery (and malignant cause)
Dexamethosone will reduce oedema around the lesion and can improve outcome
When should you call a neurosurgeon when you see a patient with possible disc prolapse or spinal cord compression?
If there are signs of cauda equina syndrome
If there are progressive neurological defects
After conservative management of a disc prolapse has failed
What is a microdiscectomy?
Removal of the herniated part of the disc to reduce the pressure on the spinal cord or spinal nerve roots
