Syringomyelia

Question 1

What is Syringomyelia?

Answer 1

A fluid-filled cyst or collection (a syrinx) in the spinal cord.

Generally when normal normal flow of CSF around spinal cord or lower brain is disrupted- compresses nerve fibres in the cord.

Question 2

What is it called when syrinxes affect the brainstem?

Answer 2

Syringobulbia

Fluid filled cavity in medulla of brainstem often an extension of Syringomyelia

Question 3

What are some causes of Syringomyelia?

Answer 3

*** Chiari malformation

Trauma

Tumours

Idiopathic

post-inflammatory - e.g. infection tuberuclosis, post-op meningitis

Question 4

Features of Syringomyelia: why do patients classically complain of burning their hands without realising?

Answer 4

• bilateral ‘cape like’ loss of spinothalamic sensation (pain, temp, pressure, crude touch etc.) in neck, shoulders and arms as the syrinx grown longitudinally and out at segmental levels.
• Especially hands as ST dermatomal arrangement mean upper body located more medially in cord.

-light touch, proprioception and vibration preserved in upper body

Question 5

Neuroanatomy and Syringomyelia: why do you get loss of temperature / pain / crude touch / pressure?

Answer 5

See Soton Brain Hub - YT video

Spinothalamic fibres cross immediately in the cord and cross the anterior white commissure near the central canal. So as the syrinx expands from the central canal it interrupts ST sending (pain, temp etc) fibres across the spinal cord - bilateral loss

Synringomyelia mainly effects spinothalamic fibres as the dorsal column fibres are more posterior in the cord - so preserved proprioception etc.

(Steve Jacques talks of how DC could eventually be effected, other resources don’t go into this much detail so i think confusing)

Question 6

What are some features of Syringomyelia?
(sensory, motor, autonomic)

Answer 6

SENSORY : ‘Cape-like’
loss of sensation to pain / temperature
Neuropathic pain

MOTOR:
Upgoing plantars
spastic weakness (mainly lower limbs)

AUTONOMIC
- Horner’s syndrome (sympathetic chain compression - rare)
- Bowel and bladder dysfunction

Scoliosis if untreated (years)

Question 7

Investigations for Syringomyelia

Answer 7

• Full spine MRI - exclude tumour / tethered cord
• Brain MRI to exclude Chiari malformation

A dynamic MRI (rapid succession of images) to show flow of fluid around spinal cord and within syrinx

Dye can be injected to enhance

Question 8

Treatment for Syringomyelia?

Answer 8

Monitoring - asymptomatic.

Surgery - symptomatic

• Treat Chiari malformation to reduce pressure
• Remove obstruction e.g. tumour
• Shunt / stent placed to drain into abdomen or chest

Question 9

Why can you get UMN in a syringomyelia?

Answer 9

IF the syrinx extends to the anterior horn can get motor involvement : weakness and absent reflexes at that level

and

UMN below the level : (increased tone, brisk reflexes, upgoing plantars)

Question 10

What is ‘dissociated sensory loss’ in syringomyelia?

Answer 10

pain and temperature sensation loss over the shoulders and upper limbs at the level of the syrinx

BUT normal proprioception and joint position sensation

can be asymmetrical depending on the syrinx.