What is syringomyelia?

Syringomyelia: Definition and Management

Syringomyelia is a rare neurological disorder characterized by the formation of a fluid-filled cyst (syrinx) within the spinal cord, resulting in myelopathy and progressive neurological deterioration if left untreated. 1, 2

Pathophysiology and Classification

Syringomyelia develops due to disturbances in cerebrospinal fluid (CSF) flow in the subarachnoid spaces, which disrupt normal flow velocity and lead to syrinx formation 2. The condition is typically classified based on anatomical features and pathogenesis:

• Foraminal syringomyelia: Related to abnormalities at the craniocervical junction, most commonly Chiari malformation
• Non-foraminal syringomyelia: Associated with causes of arachnoiditis (infection, inflammation, trauma)
• Tumor-associated syringomyelia: Related to intramedullary spinal cord tumors 2

Clinical Presentation

Symptoms typically develop during the third or fourth decades of life and include:

• Progressive sensory loss (particularly pain and temperature sensation)
• Motor weakness and paralysis
• Chronic pain
• Autonomic dysfunction
• Rare cases of syncope due to disruption of sympathetic fibers in the thoracic spinal cord 3, 1

The natural history of syringomyelia is characterized by gradual, stepwise neurological deterioration extending over many years 2.

Diagnostic Evaluation

MRI is the gold standard for diagnosis of syringomyelia:

• Complete spine MRI without IV contrast is essential as the first imaging study to:

  • Determine the extent of the syrinx
  • Identify underlying causes
  • Evaluate for associated conditions 1

• Brain MRI should be performed to evaluate for:

  • Chiari malformation (present in 98% of myelomeningocele cases) 3
  • Hydrocephalus
  • Other associated conditions 1

• Dynamic MRI with CSF velocity studies (CISS, cine-MR sequences) helps evaluate CSF flow dynamics 2

Management Approach

Surgical Treatment

Surgical management is primarily focused on treating the underlying cause of syringomyelia and re-establishing physiological CSF pathways:

• For Chiari-associated syringomyelia: Posterior fossa decompression (PFD) or posterior fossa decompression with duraplasty (PFDD) is the first-line treatment 1

• For non-foraminal syringomyelia:

  • Resection of the entity restricting CSF flow
  • Arachnoidolysis for cases with arachnoid scarring 2, 4

• Shunt procedures are typically reserved as second-line treatment or for patients who are not candidates for other procedures:

  • Syringo-peritoneal shunt
  • Syringo-subarachnoid shunt 4, 5

Conservative Management

• Asymptomatic syringomyelia or hydromyelia: No evidence supports surgical intervention; observation is recommended 1, 6

• Symptomatic management: Medical treatments for chronic pain, which is often the main long-lasting symptom 2

Prognosis and Follow-up

• Post-surgical follow-up should include MRI to assess syrinx size reduction
• Allow 6-12 months before considering additional procedures for persistent findings 1
• Neurological improvement occurs in approximately 60% of patients after shunting procedures, with decreased syrinx size 5

Important Considerations

• Syringomyelia associated with intramedullary tumors typically resolves spontaneously after tumor resection 2
• The condition requires a dedicated multidisciplinary approach for optimal management 2
• Evolutive (progressive) syringomyelia should be treated without delay due to its severe impact on quality of life 2

Associated Conditions

Syringomyelia is commonly associated with:

• Chiari malformation (98% of cases)
• Hydrocephalus (70% of cases)
• Spinal cord tethering 3
• Myelomeningocele (present in 40-80% of cases) 3

Understanding these associations is crucial for comprehensive management of patients with syringomyelia.