What is the treatment for syringohydromyelia?

Treatment of Syringohydromyelia

For symptomatic syringohydromyelia, perform posterior fossa decompression (PFD) with or without duraplasty (PFDD) as first-line surgical treatment, targeting the underlying cause—most commonly Chiari I malformation. 1, 2, 3

Initial Surgical Management

The primary surgical approach depends on the underlying etiology:

For Chiari Malformation-Associated Syrinx (Most Common)

• Both PFD alone and PFDD are acceptable first-line options for symptom relief, though PFDD may potentially provide improved syrinx resolution with dural patch grafting. 1, 2
• Surgeons may perform cerebellar tonsil resection or reduction during PFD surgery to enhance syrinx improvement and symptom resolution (Grade C recommendation). 1, 2, 3
• Indications for surgery include symptoms from cerebrospinal fluid flow obstruction, brainstem/cranial nerve compression, or radiographic evidence of tonsillar displacement with neural structure compression at the foramen magnum. 2

For Hydrocephalus-Associated Syrinx

• Treat communicating syrinxes occurring with hydrocephalus empirically with ventriculoperitoneal shunt, which achieved excellent results in 7 of 7 patients in one surgical series. 4
• Chiari II malformations with hydrocephalus similarly respond well to ventriculoperitoneal shunting (5 of 5 patients showed excellent results). 4

For Extramedullary Compression

• Excise the extramedullary obstruction at the rostral end of noncommunicating syrinxes, which resulted in cavity collapse or disappearance in 6 of 7 patients. 4
• If excision alone is insufficient, consider syringocisternal shunt placement. 4

For Post-Traumatic Syringohydromyelia

• Perform spinal or syringocisternal shunt placement, which achieved good results in all 4 patients in one surgical series. 4

Postoperative Monitoring and Timing of Reintervention

Critical timing consideration: Wait 6-12 months after initial surgery before considering additional neurosurgical intervention for persistent syringomyelia without radiographic improvement (Grade B recommendation). 1, 2, 3, 5

• This waiting period is essential because many syrinxes resolve during this timeframe, and reoperation for persistent syrinx is potentially beneficial only if the syrinx has not improved 6-12 months after initial operation. 1, 2, 5
• Symptom resolution and syrinx resolution do not correlate directly—patients may experience symptom improvement without complete radiographic resolution, or vice versa. 1, 5

Preoperative Diagnostic Evaluation

Before surgery, obtain comprehensive imaging:

• Complete MRI of entire brain and spine to evaluate for hydrocephalus, complete extent of syringomyelia, and tethered spinal cord (Grade C recommendation). 2, 3
• MRI is the gold standard, including T1 and T2-weighted sequences, FLAIR imaging, and high-resolution heavily T2-weighted 3D sequences for the spine. 3
• Evaluate for craniocervical instability preoperatively, as some patients require decompression AND fusion of the craniocervical junction. 2

Special Considerations for Specific Populations

Terminal Syringohydromyelia with Occult Spinal Dysraphism

• Large symptomatic terminal syrinxes require shunting, particularly when presenting with pain, motor/sensory deficits, scoliosis, or bowel/bladder dysfunction. 6
• Shunting showed complete or significant syrinx resolution in 10 of 11 patients on MRI, with complete pain resolution in all 5 patients who presented with back pain. 6
• One-third of shunted patients had significant postoperative neurological improvement with no worsening. 6

Intramedullary Mass-Associated Syrinx

• Manage by biopsy or excision of the causal lesion with appropriate adjunctive therapy. 4

Atrophic Syrinxes with Myelomalacia

• Do not operate on atrophic syrinxes except to relieve symptoms referable to the causal lesion. 4

Common Pitfalls to Avoid

• Do not rush to reoperation: Allow the full 6-12 month period for syrinx improvement before considering additional surgery. 1, 2, 5
• Do not assume symptom-syrinx correlation: Clinical improvement may occur without complete radiographic resolution. 1, 5
• Do not perform isolated syrinx shunting for Chiari-associated syrinx as first-line: Address the underlying Chiari malformation with posterior fossa decompression first. 1, 2, 3