Cauda Equina

Question 1

Defintion

Answer 1

Neurological emergency which occurs when the bundle of nerves below the end of the spinal cord are compressed
- damage to the spinal cord at vertebral level L1-L5
- usually presents with lower motor neurone signs (e.g. hyporeflexia + hypotonia)

Question 2

Risk factors

Answer 2

• Lumbar disc herniation (MC)
• Trauma
• Spinal tumour
• Lumbar spinal stenosis: narrowing of the spinal cord may result in CES. Some causes include spinal osteoarthritis (spondylosis), rheumatoid arthritis, and a slipped vertebra (spondylolisthesis)
  Epidural abscess or haematoma

Question 3

Signs

Answer 3

• Bilateral lower limb weakness and/or reduced sensation
• Decreased or absent lower limb reflexes
• SADDLE ANAESTHESIA: Reduced Perianal sensation (S2-S4) and anal tone
• Bladder dysfunction + sphincter involvement
• Palpable bladder due to urinary retention

Question 4

Symptoms

Answer 4

• Lower back pain and sciatica
• Saddle anaesthesia: numbness in the peri-anal region, groin and inner thighs
• Bladder and bowel dysfunction: urinary retention and incontinence or rarely faecal incontinence
• Leg weakness and difficulty walking
• Erectile dysfunction

Question 5

Investigations

Answer 5

GOLD STANDARD: MRI spine: must be requested urgently
Bladder ultrasound: to determine whether urinary retention is present; do not delay an MRI to do a bladder scan if there is a high clinical suspicion of CES

Question 6

Management

Answer 6

Emergency decompressive laminectomy: surgery should be performed within 24-48 hours of symptom onset
All patients with suspected CES should be urgently referred to neurosurgery
Early treatment reduces the risk of permanent neurological deficit
Uses a posterior midline approach and the laminas are removed to visualise the spinal cord
Corticosteroids or radiotherapy: may be considered in certain patients with CES secondary to malignancy, although optimal management remains controversial