2.2. Spine - Prolapsed Intervertebral Disk and Cauda Equina Syndrome

Question 1

What are the 2 types of Disk Protrusion which occur in the Lumbar Region, causing pain?

Answer 1

1. Lateral Disk Protrusion

2. Central Disk Protrusion

Question 2

What are the Features of the Intervertebral Disks?

Answer 2

1. They are Secondary Cartilaginous Joints
2. It is the largest Avascular Structure in the Body
3. It contains 2 Layers:
4. a) Annulus Fibrosus (Tough outer layer)
5. b) Nucleus Pulposus (Gelatinous Core)

Question 3

What happens during a Prolapsed Disk?

Answer 3

The Annulus Fibrosus (Tough outer layer) tears and the Nucleus Pulposus prolapses - causing cord / nerve root compression

Question 4

What are the 2 types of Disk Protrusion which occur in the Lumbar Region, causing pain?

Answer 4

1. Lateral Disk Protrusion (Compresses Nerve Roots)

2. Central Disk Protrusion (Compresses Roots within the Cauda Equina)

Question 5

What does the Cartilaginous End-Plate of each Intervertebral Disk attach to?

Answer 5

The Bony End-Plate of the Vertebrae

Question 6

What movements do the Intervertebral Disks resist?

Answer 6

Rotational Movement - The fibres of the Annulus Fibrosus run obliquely and alternately between layers
Note - Disks fail with twisting movements

Question 7

What happens during the normal aging process?

Answer 7

1. The water contents of the Disk Decreases

2. The Disk space narrows causing “Degenerative changes” on X-Rays and in the Facet Joints

Question 8

What are common pathological process of the Intervertebral Disk Protrusion?

Answer 8

1. Tearing of the Annulus Fibrosis and Protrusion of the Nucleus Pulposus
2. Nerve Root Compression by Osteophytes
3. Central Spinal Stenosis
4. Abnormal Movement:
5. a) Spondylolysis
6. b) Spondylolisthesis

Question 9

What are the features of Nerve Root Pain?

Answer 9

1. Limb Pain is worse than Back Pain
2. Pain in a Nerve Root Distribution (Radicular)
3. Root Tension Signs
4. Root Compression Signs
5. Dermatomes and Myotomes affected

Question 10

How is Nerve Root Pain managed?

Answer 10

1. About 90% settle in 3 months
2. Physiotherapy
3. Stong Analgesia
4. Referral after 12 weeks for MRI (imaging)

Question 11

What are the 4 types of Disk Problems, which can cause Nerve Root Pain?

Answer 11

1. Disk Bulge
2. Disk Protrusion
3. Disk Herniation
4. Disk Sequestration

Question 12

What is a Disk Bulge?

Answer 12

Generalized enlargement of the Disk

Note - this is common and the majority are asymptomatic

Question 13

What is a Disk Protrusion?

Answer 13

The Annulus Fibrosus is weakened but still in tact

Question 14

What is a Disk Herniation?

Answer 14

The Nucleus Fibrosus has run through the Annulus Fibrosus (it is no longer still in tact)

Question 15

What is a Disk Sequestration?

Answer 15

Dessicated Disk Material is Free in the Canal

Question 16

Where do Disk Problems most commonly occur, in the Thoracic Region?

Answer 16

Mid to Lower Levels (75% at T8-12), with Most occurring at T11/12
Note - This accounts for <1% of Intervertebral Disk Prolapses

Question 17

Where do Disk Problems most commonly occur, in the Thoracic Region?

Answer 17

Mid to Lower Levels (75% at T8-12), with Most occurring at T11/12
Note - This accounts for <1% of Intervertebral Disk Prolapses

Question 18

Where do Disk Problems most commonly occur, in the Lumbar Region?

Answer 18

1. L4/5 (45%)
2. L5/S1 (40%)
3. L3/4 (10%)

Question 19

What type of Herniation commonly occurs at the Lumbar Region?

Answer 19

Posterolateral

Question 20

How does Central Disk Protrusion, from the Lumbar Region, present?

Answer 20

1. Pain in both legs

2. Pain in the back only

Question 21

What is the common name for a Central Disk Protrusion in the Lumbar Region?

Answer 21

Cauda Equina Syndrome

Question 22

How serious is Cauda Equina Syndrome?

Answer 22

It is a Surgical Emergency

Question 23

Other than a Central Lumbar Herniated Disk, what can cause Cauda Equina Syndrome?

Answer 23

1. Tumours
2. Trauma
3. Spinal Stenosis
4. Epidural Abscess
5. Iatrogenic:
6. a) Spinal Manipulation
7. b) Spinal Epidural
8. c) Surgery

Question 24

What are the Clinical Features of Cauda Equina Syndrome?

Answer 24

1. Injury / Precipitating Event
2. Bilateral Buttock + Leg Pain
3. Varying Dysaethesia + Weaknes
4. Bowel / Bladder Dysfunction
5. Saddle Anaesthesia - Loss of Anal Tone & Reflex
6. High index of suspicion in Spinal Post-op patients

Question 25

How is the severity of Cauda Equina Syndrome evaluated?

Answer 25

1. MRI

2. Lumbar CT or Myelogram (if MRI is contraindicated)

Question 26

What are the potential outcomes of Cauda Equina Syndrome?

Answer 26

1. 30% undergoing discectomy did NOT regain normal Urinary Function
2. 25% with motor deficits never regained full power
3. 33% with sensory deficits never regained normal sensation
4. 25% with perianal paraesthesia did not return to norma
5. 26% had persistent Sexual Dysfunction

Question 27

What are the potential outcomes of Cauda Equina Syndrome?

Answer 27

1. 30% undergoing discectomy did NOT regain normal Urinary Function
2. 25% with motor deficits never regained full power
3. 33% with sensory deficits never regained normal sensation
4. 25% with perianal paraesthesia did not return to norma
5. 26% had persistend Sexual Dysfunction