My cervical MRI revealed a syrinx; what is a cervical syrinx?

What Is a Cervical Syrinx?

A cervical syrinx is a fluid-filled cavity (cyst) that forms within your spinal cord in the neck region, creating a longitudinal channel that can expand over time and damage nerve tissue. 1, 2

Understanding the Condition

• A syrinx is essentially a pocket of cerebrospinal fluid (CSF) trapped inside the spinal cord itself, rather than flowing normally around it 1
• The cervical region (neck) is the most common location for syrinx formation 1
• The cavity typically extends across multiple vertebral levels—on average spanning two vertebral segments in the cervical spine 1

Common Causes

The syrinx on your MRI likely developed from one of these mechanisms:

Most Common Associations

• Chiari malformation: Abnormal positioning of the cerebellar tonsils at the base of the skull, obstructing CSF flow 1, 2
• Cervical disc disease: Herniated discs or degenerative changes causing compression and CSF pathway obstruction 1, 3
• Spinal cord trauma: Previous injury to the spine 1, 2
• Spinal cord tumors: Masses blocking normal fluid circulation 1, 4

Less Common Causes

• Spinal infections 1
• Demyelinating diseases like multiple sclerosis (rare) 5
• Idiopathic (no identifiable cause in some patients) 2

How Syrinx Forms

• The primary mechanism is obstruction of CSF pathways around the spinal cord 1
• Complete obstruction tends to cause syrinx formation below (distal to) the blockage 1
• Partial obstruction can cause syrinx formation either above or below the obstruction point 1
• In cervical disc disease, intermittent spinal cord compression creates pressure dissociation that allows fluid to accumulate within the cord 3

Why This Matters Clinically

Your neurologist needs to identify the underlying cause because treatment of the primary problem (such as decompressing a herniated disc or addressing a Chiari malformation) can lead to syrinx resolution and symptom improvement. 1, 3

Potential Symptoms

• Progressive weakness in arms or legs 2, 3
• Loss of pain and temperature sensation (while touch sensation may be preserved) 2
• Severe radicular pain radiating down the arms 3
• Bladder dysfunction 5
• Difficulty walking 2, 5

Critical Next Steps

The Congress of Neurological Surgeons mandates that you undergo complete spine MRI (entire cervical + thoracic + lumbar spine) without contrast to detect associated pathology such as Chiari malformation, spinal cord tumors, or additional syrinx cavities that could influence your treatment. 6

• Brain MRI should also be obtained if not already done, to evaluate for Chiari malformation or posterior fossa tumors 6, 4
• Intravenous contrast is unnecessary for routine syrinx evaluation because the fluid cavity is readily visible on T2-weighted MRI sequences 6

Treatment Implications

• If cervical disc disease is the cause, surgical decompression and stabilization of the affected disc levels can result in syrinx resolution 1, 3
• If Chiari malformation is present, posterior fossa decompression may be needed 7, 4
• Restoration of normal CSF flow pathways is the key therapeutic principle regardless of cause 1
• Some patients show radiographic decrease in syrinx size immediately after appropriate surgical intervention 2

Important Caveats

• Not all syrinxes cause symptoms—some are discovered incidentally 4
• However, progressive neurologic symptoms warrant urgent evaluation and treatment to prevent irreversible spinal cord damage 2
• Long-term follow-up imaging is required after treatment to monitor for syrinx recurrence 2