Compartment and Cauda Equina syndromes

Question 1

What’s compartment syndrome?

What happens?

Answer 1

It’s a critical pressure increase within a confined space (compartment)

perfusion pressure to the tissues in the compartment is reduced -> ischaemia and necrosis

Question 2

What are the complications of untreated compartment syndrome?

Answer 2

• limb loss
• multiorgan failure
• death

Question 3

Possible causes of compartment syndrome

Answer 3

• trauma to the affected area
• fractures that cause vascular injury
• iatrogenic causes (e.g. vascular injury post-op)
• tight casts or splints
• DVT
• post-reperfusion syndrome swelling

Question 4

Characteristic presenting features of Compartment Syndrome

Answer 4

• pain (worsening despite treatment, disproportionate to the injury, worse on passive movement)
• paraesthesia - in a cutaneous distribution of a nerve that is compressed
• generalised muscular tenderness
• swelling

*as a disease progresses -> features of acute arterial insufficiency develop (5’ Ps)

Question 5

Features of arterial insufficiency (6 ‘Ps)

Answer 5

• pallor
• pulseless
• paraesthesia
• perishingly cold
• pain
• paralysis

Question 6

DIagnosis of compartment syndrome

Answer 6

• it is usually clinical
• suspicion in a post-op patient
• MRI of affected compartment -> if diagnosis is in doubt

Question 7

Initial management of Compartment Syndrome (prior to definitive intervention)

Answer 7

• early recognition is important
• inform plastic/genera/orthopaedic surgeon
• keep the limb at neutral level (do not elevate or lower)
• increase blood pressure -> crystalloid fluids
• high flow oxygen
• remove any constricting dressings, splits, casts
• opioid analgesia and anti-emetics

Question 8

Definitive management of Compartment Syndrome

Answer 8

Emergency Open Fasciectomy -> to relieve the pressure inside the compartment

Question 9

What happens after open fasciectomy?

What needs to be monitored?

Answer 9

• the skin incisions are left open -> re-looked at after 24-48 hours
• monitor renal function and electrolytes closely -> risk of rhabdomyolysis and reperfusion syndrome

Question 10

What signs (lower or upper motor neurone) does cauda equina produce?

Answer 10

Cauda Equina = lower motor neurone signs

Examples: hypotonia, hyporeflexia, downgoing plantars

Question 11

Gold standard investigation for Cauda Equina syndrome

Answer 11

Whole spine MRI

Question 12

How common cauda equina is? What’s peak age onset?

Answer 12

Peak age onset is 40-50 years old

4 in 10 000 people this age, presenting with lower back pain will have it

Question 13

What nerve roots can be affected by Cauda Equina?

Answer 13

L1 - S5

Question 14

What the cauda equina innervates?

Answer 14

Sensory and motor impulses -> lower limbs

Motor -> anal sphincter

Parasympathetic -> bladder

Question 15

Pathophysiology (and causes) of Cauda Equina

Answer 15

Cauda equina syndrome is caused by compression of the cauda equina:

• Disc herniation – most common at L5/S1 and L4/L5 level
• Trauma – including vertebral fracture and subluxation
• Neoplasm
• Infection – e.g. discitis or Potts disease
• Chronic spinal inflammation – e.g. ankylosing spondylitis
• Iatrogenic – e.g. haematoma secondary to spinal anaesthesia

Question 16

Symptoms of Cauda Equina

Answer 16

• reduced lower limbs sensation (often bilateral)
• bladder and anal sphincter dysfunction
• importance
• lower limb muscular weakness
• severe back pain

*lower motor neurone signs

Question 17

What may be seen on examination of a patient with Cauda Equina Syndrome?

Answer 17

• perianal (the lower sacral dermatomes, termed “saddle” anaesthesia)
• lower limb anaesthesia
• loss of anal tone
• urinary retention
• lower limb weakness and hyporeflexia

Question 18

What clues may be there in the history of a patient presenting with cauda equina syndrome?

Answer 18

• weight loss
• signs of malignancy/ metastatic disease
• living in area of endemic TB

Question 19

What (2) elements should be involved in the examination of every patient presenting with suspected cauda equina syndrome?

Answer 19

• PR
• post-voiding bladder scan

Question 20

Differential diagnosis of Cauda Equina Syndrome (2)

*how to distinguish these from CES?

Answer 20

• Radiculopathy – presents with radiating back pain, however there will be no faecal, urinary, or sexual dysfunction in these patients
• Cord compression – a surgical emergency with a similar pathophysiology to CES, however is characterised by upper motor neurone signs

Question 21

Management of Cauda Equina Syndrome

Answer 21

• early neuro-surgical review -> for early decompression
• high dose steroids e.g. Dexamethasone -> to reduce localised swelling
• immobilisation -> in case of trauma
• surgical decompression -> if neuro-surgeons opinion is to do so
• management of malignancy (if that is the case) -> radiotherapy, chemotherapy etc

Question 22

Prognosis for Cauda Equina Syndrome

Answer 22

• variable
• depends on the time between the first onset of autonomic dysfunction to the treatment