Degenerative Disorders (Cervial Disc Prolapse)

Cervical Disc Prolapse

 

Back ground:

• The cevical spine is very mobile and is liable to osteoarthiritic changes(cervical spondylosis). This affects more than 50% of people above 50 years.
• 20% of those affected develop symptoms.

Definition:

• It is herniation of nucleus puposis of the intervertebral disc through a tear in the annulus fibrosis.

Aetiology:

• Degenerative is the most important(spondylosis).
• Traumatic is less important.
• Both.

Pathophysiology:

• Two clinical types of cervical disc prolapse are known: soft disc& hard disc(spondylosis)
• The stages are

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       Soft Disc                                                         Hard Disc
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Laceration of annulus fibrosis                     Instability(degeneration)
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Protrusion of nucleus pulposis           Osteophytes formation+_compression

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Extrusion of nucleus pulposis                             Stabilization
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• Directions of the cervical disc prolapse:

Posterolateral>>> root compression>>>Radiculopasy.
Posterior>>> spinal cord compression>>> Myelopathy.

Clinical Picture:

1)Related to annulus tearing or spine degeneration and instability:

• Neck and interscapular pain of referred type.
• Spasm of muscles>>> straight cervical spine.

2)Related to neural compression:

A)IN posterolateral disc herniation:
1)Sensory:

• Radicular pain(Brachialgia):which is asharp lancinating pain radiating along one of the dermatomes of upper limbs.
• Numbness and paresthesia.

2)Motor(lower motor neuron lesion)

• Motor weakness and muscle wasting and fasciculation.

3)Autonomic:

• Negligible.

B)IN posterior disc herniation(Myelopathy):
Sensory

• Numbness and paresthesia below the level of lesion.
• Lhermitte sign:Electric like pain radiating down the spine provoked by neck flexion.

Motor(upper motor neuron lesion):

• Hpertonia.
• Hyperreflexia.
• Weakness of lower limbs.
• Babiniski sign.

Autonomic

• Precipitancy of urine.

Differential Diagnosis:

• Amyotrophic lateral sclerosis(mixure of upper and lower motor neuron lesions).

Investigation:

1)MRI:

• Is the modality of choice.
• Demonstrates the prolapsed disc and any canal stenosis.

2)X-ray(A-P and Lateral)

• Has a limited value in diagnosis of lumbar disc. It shows a reduced disc height& osteophytes.
  
  • On the contrary it is very useful in

1. Spondylolisthesis
2. Detects spina bifida
3. Detects secondary tumros

3)CT scan is useful but to a less degree than MRI.

4)Myelography is invasive and no longer used.

Treatment:

1)Conservative:

1. Neck collar and traction.
2. Analgesics
3. Muscle relaxant.

2)Surgical:

Indications of surgery:

1. Failure of conservative treatment.
2. Intolerable pain in spite of initiation of conservative treatment.
3. Progressive motor weakness.
4. Cauda equina syndrome.

Surgical procesures

1)Soft disc:

• Discectomy by anterior approach via incision.

2)Hard disc:

• Discectomy by anterior approach via neck incision+removal of the osteophytes+fusion of vertebrae by a bone graft.