Syringomyelia Flashcards
What is syringomyelia?
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.
What is the typical age of onset of synringomyelia?
30 years old
What are causes of syringomyelia?
-
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
What are symptoms of syringomyelia?
- Upper limb pain exacerbated by exertion/coughing
- Numbness
- Weakness
What is Arnold-Chiari malformation?
Cerebellum herniates through foramen magnum
What is basilar invagination?
Where the top of the odontoid peg migrates upwards, causing foramen magnum stenosis +/- medulla oblongata compression
What are signs seen in syringomyelia?
- 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
What is dissociated sensory loss?
Absent pain and Temperature sensation, with preserved light touch, vibration and proprioception
Why do you get dissociated sensory loss in syringomyelia?
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)
What is thought to causes unilateral large feet/hands, body asymmetry or limb hemihypertrophy in syrinomyelia?
Release of trophic factors via anterior horn cells
What are features of syringobulbia?
Brainstem involvement
- Nystagmus
- Vertigo
- Bulbar palsy - Tongue atrophy/fasciculations, Dysphagia, Pharyngeal/palatal weakness, dysarthria, hoarseness
- Horner’s syndrome
- CNV palsy
What investigation would you consider doing in someone with suspected syringomyelia?
MRI - shows syrinx
How would you manage someone with syringomyelia?
-
Surgical Decompression
- Foramen magnum - Arnold-Chiari malformation - promote free flow of CSF