Spinal cord compression (incl. cauda equina)

Question 1

Describe the dermatomes of the lower limbs.

Answer 1

Question 2

What are the most common causes of spinal cord compression?

Answer 2

1. Trauma - leading cause of acute SCC (e.g. falls, RTA)
2. Vertebral compression fractures - weakened bone fractures with low-level trauma
3. Intervertebral disc disease
4. Tumours
5. Infection - discitis, TB, epidural abscess

Question 3

How does intervertebral disc disease cause spinal cord compression?

Answer 3

Disc herniation = rupture of nucleus pulposus –> through fibres of annulus fibrosis –> into intervertebral space –> compresses nerve roots

Symptoms = paraesthesia, pain, power reduced indicative of lumbar radiculopathy/sciatica

Question 4

List 3 types of tumours which can cause SCC.

Answer 4

• Primary sarcoma
• CNS tumours e.g. ependymoma, meningioma, glioma
• Multiple myeloma
• Metastatic breast, prostate, renal, small cell lung cancers

Question 5

List 3 causes of acute compression of cauda equina.

Answer 5

• Bony metastasis
• Myeloma
• Epidural abscess
• Disc prolapse
• Epidural haematoma
• Primary sacral tumour e.g. chordoma

Question 6

What is TB causing spinal compression called?

Answer 6

Pott’s disease of the spine

Question 7

List 5 red flag symptoms for lower back pain, suggesting SCC.

Answer 7

1. Bilateral sciatica
2. Bladder dysfunction
3. Perineal paraesthesia
4. Gait disturbance
5. Lower limb weakness
6. Erectile dysfunction

Question 8

What are the motor, sensory and autonomic symptoms of incomplete spinal cord compression?

Answer 8

Sensory - altered sensation below certain level/ hemisensory loss

Motor - hemiplegia/paresis (sparing face) [or para or tetra]

Autonomic

• constipation
• urinary retention
• dizziness (due to hypotension)
• cold, shivering, drowsiness (due to hypothermia)
• ED
• abdominal pain and distension (due to ileud)
• syncope (due to bradycardia)

PAIN is also common - often sharp, radicular pain.

Question 9

Which 4 tumours commonly metastasise to the spine and can contribute to SCC?

Answer 9

• Small cell lung cancer
• Non-small cell lung cancer
• Breast cancer
• Prostate cancer
• Renal cancer

Question 10

What are the signs and symptoms of cauda equina syndrome? What is a common cause of cauda equina syndrome?

Answer 10

Commonly due to disc compression and stenosis of the spinal canal.

Symptoms:

• Low back pain
• Bilateral sciatica
• Bladder retention/incontinence
• Saddle anaesthesia (perineal)
• Leg weakness

Signs:

• Sensory loss in lumbosacral distribution
• Reduced tone in legs (flaccid)
• Reduced power in legs
• Reduced reflexes (!!)
• Anal sphincter tone loss

Question 11

List 2 differences between the examination of cauda equina compression and cord compression.

Answer 11

BOTH cause power loss and sensory loss

• Cauda equina causes flaccid paralysis and loss of reflexes
• SCC causes spastic paralysis and brisk reflexes

Question 12

What are the early signs of spinal shock and how do these progress in SCC?

Answer 12

Spinal shock - areflexia and hyporeflexia

This is later replaced by increased tone, hyper-reflexia and +ve Babinski

NB: bilateral signs are uncommon in disc herniation.

Question 13

What causes Brown-Sequard’s syndrome? What are the clinical signs/symptoms?

Answer 13

BSS = hemisection lesion of the spinal cord and most commonly seen after trauma

Signs/symptoms:

• Ipsilateral below level of lesion:
  
  • segmental anaesthesia
  • paralysis
  • loss of vibration
  • loss of proprioception
  • hyper reflexia
• Contralateral below level of lesion:
  
  • loss of pain
  • loss of temperature sensation

Question 14

How is cauda equina syndrome managed?

Answer 14

Urgent spinal surgical admission same day - must be done within hours and even waiting until the next day may allow irreversible damage and paralysis to occur.

Question 15

What is the difference between anterior and posterior cord syndrome?

Answer 15

Anterior cord syndrome - anterior spinal tracts affected, including vestibulospinal tract –> loss of pain/temperature sensation + paralysis below level of lesion (spares touch, proprioception, vibration)

Posterior cord syndrome (rare) - posterior spinal tracts affected usually due to posterior spinal artery occlusion –> loss of pain, position, vibration below level of lesion.

Question 16

What investigations would you do for SCC?

Answer 16

MRI/CT (1st line) - anteroposterior, lateral and special views required to show alignment of bones. Gandolinum-enhanced MRI can exclude infection including osteomyelitis/epidural abscess.

Plain spine x-ray - helpful in trauma combined with CT

Other:

• Clotting studies - pre-op
• FBC - pre-op
• Electrolytes
• CSF analysis - not diagnostic but may be useful for excluding non-traumatic causes of SCI e.g. transverse myelitis, HIV myelopathy, infection.
• ESR/CRP

Question 17

Define spinal cord compression.

Answer 17

Spinal cord compression occurs when there is compression of the spinal cord or cauda equina at any level secondary to the effects of a malignancy.

Question 18

What are the causes of spinal cord compression?

Answer 18

• Trauma e.g. car accident, falls, diving
• Vertebral compression fracture
• Intervertebral disc herniation
  
  • rupture of the nucleus pulposus in the intervertebral space, through the fibres of the annulus fibrosis
• Primary or secondary metastatic spinal tumour
• Infection e.g. discitis, TB (Pott’s), epidural abscess

This can include metastatic infiltration to the vertebral column causing instability or pathological fractures as well as direct pressure from malignancy to the spinal cord.

Question 20

How common is spinal cord compression?

Answer 20

Affects 15% of cancer patients

More common in lung, prostate and breast cancers

But 20% occurs in those without cancer diagnosis

Question 21

What are the signs and symptoms of spinal cord compression?

Answer 21

• Back pain (predates neurological symptoms by 7 weeks)
  
  • usually in thoracic region
  • worse when lying flat or coughing/straining
  • worse at night
  • continuous in nature
• Numbness, sensory disturbance
• Motor weakness (late)
• Bladder and bowel dysfunction (late)

Question 22

What examination should be done in suspected spinal compression?

Answer 22

• Give analgesia as full examination of upper and lower limbs will be needed.
• PR exam
• Bladder scan (pre and post void) for signs of urinary retention

Question 23

What investigations should be done to diagnose spinal compression?

Answer 23

• MRI whole spine - GOLD STANDARD and must be done within 24hrs
  
  • CT scan if MRI is contraindicated

Question 24

What is the management of spinal cord compression?

Answer 24

• Loading dose dexamethasone 16mg immediately - unless contraindications e.g. 10mg stat then 16mg daily with PPI cover.
  
  • contraindicated if there is suspicion of lymphoma
• Analgesia
• VTE prophylaxis (cancer increases risk)
• Inform local oncology centre + discuss possible transfer of care
• Refer to neurosurgery

Other management options:

• Radiotherapy
• Surgery
• Nurse patent in neutral alignment, insert catheter, bisphosphonates in all cancer patients with bone mets

Question 25

Where does the spinal cord end?

Answer 25

From foramen magnum to L1/L2

NB: umbilicus is L3/4, PSIS is S2

Question 26

What are the most common levels of disc prolapse?

Answer 26

L4-L5 and L5-S1 Large disc herniations can cause cauda equina syndrome

Question 27

Define cauda equina syndrome.

Answer 27

Compression of the nerve roots caudal to the level of the spinal cord, causing one or more of the following: * bladder and/or bowel dysfunction, * reduced sensation in the saddle (perineal) area, * and sexual dysfunction, * with possible neurological deficit in the lower limb (motor/sensory loss, reflex change)

Question 28

What cauda equina red flags should have early referral according to NICE CKS?

Answer 28

* Bilateral sciatica * Severe or progressive bilateral neurological deficit of the legs, such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion * Difficulty initiating micturition or impaired sensation of urinary flow, if untreated this may lead to irreversible urinary retention with overflow urinary incontinence * Loss of sensation of rectal fullness, if untreated this may lead to irreversible faecal incontinence * Perianal, perineal or genital sensory loss (saddle anaesthesia or paraesthesia) * Laxity of the anal sphincter.

Question 29

How common is CES?

Answer 29

CES is reported in approximately 0.04% of all patients presenting with low back pain. Occurs in approximately 2% of cases of herniated lumbar discs

Question 30

What is the most common cause of CES? What are the other causes of CES?

Answer 30

**Most common: compression from lumbar herniation at L4/L5, L5/S1** * Tumours - bony mets or sacral tumour e.g. chondrome * Myeloma * Trauma --\> disc prolapse * Infection e.g. epidural abscess * Congenital * Spondylolisthesis * Late stage ankylosing spondylitis * Postoperative epidural haematoma

Question 31

What are the clinical features of CES?

Answer 31

* Usually sudden onset within hours-days * Low back pain * Sensory abnormality (may be unilateral) * Usually asymmetrical weakness with loss of reflexes * Bowel/bladder dysfunction * Saddle and perineal anaesthesia * Urinary dysfunction e.g. retention, difficulty starting/stopping * Faecal incontinence and constipation * Erectile dysfunction Investigations done as for spinal cord compression.

Question 32

What is the management of CES?

Answer 32

* Refer immediately to neurosurgery - **_arrange urgent spinal admission that day_** * **_​_**Must be done same day as waiting until next day may allow irreversible damage and paralysis to occur * Surgery - to decompress or for lesion debulking * Radiotherapy - if surgery cannot be performed * Analgesia

Question 33

What are some differentials for a spastic paraparesis?

Answer 33

demyelination MND cerebral tumour syrinx (syringomyelia) - cysts form within the spinal cord subacute combined cord degeneration

Question 34

Which signs differentiate cord compression from cauda equina?

Answer 34

Cauda equina compression causes **_flaccid paralysis_** with **_loss of reflexes._** Cord compression usually **_causes spastic paralysi_**s with **_brisk reflexes._** *Both* cause **sensory** and **power** loss.