Syringomyelia

Question 1

What is syringomyelia?

Answer 1

A syrinx is a fluid-filled tubular cavity in or close to the central canal of the spinal cord.

Central canal of spinal cord distends and begins to damage neurones by pressure effect. The swelling starts in the cervical cord and can spread up or down.

When it extends into brainstem it is termed syndringobulba.

Question 2

What is the typical age of onset of synringomyelia?

Answer 2

30 years old

Question 3

What are causes of syringomyelia?

Answer 3

• Blocked CSF circulation
  
  • Arnold-chiari malformation
  • Basal arachnoiditis
  • Basilar invagination
  • Masses
• Following myelitis
• Following trauma
• Ruptured AV malformation
• Spinal tumours - fluid secretion from neoplastic cells

Question 4

What are symptoms of syringomyelia?

Answer 4

• Upper limb pain exacerbated by exertion/coughing
• Numbness
• Weakness

Question 5

What is Arnold-Chiari malformation?

Answer 5

Cerebellum herniates through foramen magnum

Question 6

What is basilar invagination?

Answer 6

Where the top of the odontoid peg migrates upwards, causing foramen magnum stenosis +/- medulla oblongata compression

Question 7

What are signs seen in syringomyelia?

Answer 7

• Suspended area of dissociated sensory loss
• Wasting/weakness of hands +/- claw hand spreading to arm -> shoulders-> respiratory muscles
• Horner’s syndrome
• UMN leg signs
• Body asymmetry
• Limb hemihypertrophy
• Unilateral hand/foot enlargement
• If syringobulba - nystagmus, dyshpagia, tongue atrophy, palatal weakness

Question 8

What is dissociated sensory loss?

Answer 8

Absent pain and Temperature sensation, with preserved light touch, vibration and proprioception

Question 9

Why do you get dissociated sensory loss in syringomyelia?

Answer 9

Due to pressure from the syrinx on the decussating anterolateral pathways in a root distribution reflecting the location of the syrinx (e.g. cervical syrinx causes sensory loss over trunk and arms)

Question 10

What is thought to causes unilateral large feet/hands, body asymmetry or limb hemihypertrophy in syrinomyelia?

Answer 10

Release of trophic factors via anterior horn cells

Question 11

What are features of syringobulbia?

Answer 11

Brainstem involvement

• Nystagmus
• Vertigo
• Bulbar palsy - Tongue atrophy/fasciculations, Dysphagia, Pharyngeal/palatal weakness, dysarthria, hoarseness
• Horner’s syndrome
• CNV palsy

Question 12

What investigation would you consider doing in someone with suspected syringomyelia?

Answer 12

MRI - shows syrinx

Question 13

How would you manage someone with syringomyelia?

Answer 13

• Surgical Decompression
  
  • ​Foramen magnum - Arnold-Chiari malformation - promote free flow of CSF