session 1

Question 1

Define cauda equina and why we have this

Answer 1

Cauda equina (“horse’s tail”) is the bundle of spinal nerves composed of L2- L5, S1-S5 and Co1. They arise from the conus medullaris of the spinal cord and leave the spinal canal via the intervertebral foramina inferior to their respective vertebra. 
Due to a disparity in growth of the vertebral column and the spinal cord during development, the spinal cord terminates at L1 or L2, hence the spinal nerves have a relatively long path to the correct intervertebral foramina.

Question 2

Name five possible causes of cauda equina syndrome

Answer 2

1. Canal-filling disc
2. tumours (primary or secondary) affecting the vertebral column or meninges
3. spinal infection / abscess;
4. spinal stenosis secondary to arthritis
5. vertebral fracture
6. spinal haemorrhage;
7. late-stage ankylosing spondylitis.

Question 3

What are the red flag symptoms of cauda equina syndrome?

Answer 3

• bilateral sciatica
• perianal numbness (saddle anaesthesia)
• painless retention of urine
• urinary / faecal incontinence erectile dysfunction.

Question 4

How is cauda equina diagnosed?

Answer 4

MRI of the spine is the gold standard.

Question 5

What is the treatment for cauda equina?

Answer 5

Urgent surgical decompression (for good prognosis, must be performed within 48 hours of onset of symptoms)

Question 6

What complications may occur cauda equina syndrome is not treated quickly?

Answer 6

• chronic pain
• sexual dysfunction / impotence
• urinary retention (requiring intermittent self-catheterisation)
• faecal incontinence or faecal impaction (requiring manual evacuation of the rectum)
• lower limb weakness and altered sensation.

Question 7

Define sciatica

Answer 7

pain caused by irritation or compression of one or more of the nerve roots that contribute to the sciatic nerve.

Question 8

what is the typical distribution of pain in sciatica and pattern of paraesthesia due to compression of the L4 nerve root?

Answer 8

pain- anterior thigh, anterior knee, medial leg

paraesthesia- medial leg

Question 9

what is the typical distribution of pain in sciatica and pattern of paraesethesia due to compression of the L5 nerve root?

Answer 9

pain- lateral thigh, lateral leg, dorsum of foot

paraesthesia- lateral leg and dorsum of foot

Question 10

what is the typical distribution of pain in sciatica and pattern of paraesthesia due to compression of the S1 nerve root?

Answer 10

pain- posterior thigh, posterior leg, heel, lateral border and sole of foot, (sometimes with a strip up the midline of the posterior leg).

paraesthesia- lateral border and sole of foot (sometimes with a strip up the midline of the posterior leg)

Question 11

State four factors that contribute to the stability and mobility of the vertebral column

Answer 11

• thickness and compressibility of the intervertebral discs
• shape and orientation of the intervertebral facet joints
• tone of the back muscles
• resistance of the ligaments of the vertebral column.

Question 12

Movements of the vertebral column that can occur in the cervical region.
Explain what anatomical features determine the movements possible in each region

Answer 12

Flexion and extension – 50% takes place at the atlanto-occipital joint and 50% in the intervertebral joints from C2/3 down to C7/T1. Rotation 50% takes place at the atlanto-axial joint (C1-2) and 50% in the intervertebral joints from C2/3 down to C7/T1. Flexion, extension and lateral flexion of the vertebral column involve compression of the discs at one margin and stretching at the other. Flexion, extension, and lateral flexion of the neck are permitted because of the thin discs, loose articular capsules and almost horizontal plane of the articular processes.

Question 13

Movements of the vertebral column that can occur in the thoracic region.
Explain what anatomical features determine the movements possible in each region

Answer 13

The thoracic region is relatively stable because of its connection to the sternum via the ribs and costal cartilages. The articular processes are orientated posterolaterally (superior) and anteromedially (inferior). This permits rotation but prevents flexion and extension. Lateral flexion is prevented by the ribs.

Question 14

Movements of the vertebral column that can occur in the lumbar region.
Explain what anatomical features determine the movements possible in each region

Answer 14

Extension from the anatomical position (15°) is most marked in the lumbar region compared with other regions of the vertebral column.
The lumbar articular processes are orientated at 90° to the axial (transverse plane) and at 45° to the coronal plane, permitting a large range of flexion and extension but severely limiting rotation.

Question 15

Define kyphosis and lordosis

Answer 15

Kyphosis is an anterior flexion curvature (C-shaped, concave anteriorly) of the spine.
Lordosis is a posterior flexion curvature (concave posteriorly) of the spine.

Question 16

In which regions of the normal adult spine would kyphosis and lordosis be expected?

Answer 16

Kyphoses are usually found in the thoracic, sacral and coccygeal (or sacrococcygeal) regions of the spine.
Lordoses are usually found in the cervical and lumbar spine

Question 17

What are the secondary curvatures of spine and why do they develop?

Answer 17

The cervical lordosis develops when a young child learns to hold up its head and the lumbar lordosis when it learns to walk upright.
When the child makes these postural changes, the intervertebral discs become more wedge-shaped leading to the development of the secondary curvatures.

Question 18

State the two conditions (pathological or physiological) in which the normal lumbar lordosis commonly becomes exaggerated?

Answer 18

In pregnancy or truncal obesity, the centre of gravity moves anteriorly and the lumbar lordosis becomes more exaggerated.

Question 19

Describe the pathophysiological processes that result in a decrease in height and loss of secondary curvature of the spine in old age

Answer 19

With increasing age, the annulus fibrosis of the intervertebral discs begins to undergo degeneration (because of wear and tear). The nucleus pulposus loses its turgor and becomes thinner because of dehydration and degeneration. These degenerative processes account for some loss of height in all people. Osteoporotic compression fractures of the vertebrae can lead to a further reduction in overall height in some patients.
Disc atrophy, with or without accompanying osteoporotic fractures, means that the secondary curvatures start to disappear, and a continuous primary curvature is re-established. This is the ‘senile kyphosis’.