Cauda Equina

Question 1

What is cauda equina syndrome?

Answer 1

Surgical emergency caused by the compression of the cauda equina

Question 2

What is the cauda equina?

Answer 2

Bundle of nerves inferior to spinal cord

Spinal cords ends at L1
Nerve roots L1-S5 pass down spinal canal as cauda equina

Form of lower motor neurones

• motor/sensory impulses to lower limbs
• motor innervation to anal sphincters
• parasympathetic innervation to bladder

Question 3

Causes of cauda equina

Answer 3

Disc herniation
Trauma
Neoplasm 
Infection 
Iatrogenic

Question 4

Clinical features of cauda equina

Answer 4

Lower motor neurone signs 
Reduced lower limb sensation
Bladder/bowel dysfunction
Lower limb motor weakness
Saddle anaesthesia

Question 5

What are lower motor neurone signs?

Answer 5

Weakness
Wasting
Hypotonia
Areflexia 
Fasiculations

Question 6

Investigations for suspected cauda equina

Answer 6

PR exam
Post-void bladder scan

Urgent whole spine MRI

Question 7

Classification of cauda equina

Answer 7

CESR (cauda equina syndrome with retention)

• back pain
• unilateral/bilateral sciatica
• lower limb motor weakness
• saddle anaesthesia
• loss of anal tone
• loss of urinary control

CESI (incomplete cauda equina syndrome)

• back pain
• unilateral/bilateral sciatica
• lower limb motor weakness
• saddle anaesthesia
• loss of anal tone
• altered urinary sensation

CESS (suspected cauda equina syndrome)

• severe back + leg pain
• variable neurological signs
• suggestion of sphincter disturbance

Question 8

Management of cauda equina syndrome

Answer 8

High dose steroids - reduce local swelling

Surgical decompression