Intervertebral disc prolapse

Question 1

Describe the makeup of an intervertebral disc

Answer 1

Intervertebral discs consist of concentric collagenous fibres (the annulus fibrosus) surrounding a central nucleus (the nucleus fibrosus) of degenerated collagen

Healthy discs contain a great deal of water

Question 2

How does intervertebral disc prolapse occur?

Answer 2

As a result of ageing the discs become dehydrated and weaken - more prone to prolapse

Prolapse of a disc occurs when there is a defect in the annulus fibrosus that allows the nucleus to herniate out

Herniation often occurs as the result of strenuous physical activity involving the lumbar spine

Question 3

How does intervertebral disc prolapse present?

Answer 3

The prolapsed disc material can press (impinge) on an exiting nerve root resulting in pain and altered sensation in a dermatomal distribution as well as reduced power in a myotomal distribution

Question 4

What is the most common location of intervertebral disc prolapse?

Answer 4

The commonest site for this to occur in the spine is the lower lumbar spine with the L4, L5 and S1 nerve roots contributing to the sciatic nerve and pain radiating to the part of the sensory distribution of the sciatic nerve