Syringomyelia without an obvious cause, such as a Chiari malformation, a tumor, or a spinal injury, is rare and may be associated with an arachnoid web or cyst. In the literature, conventional myelography is the diagnostic method of choice. In this retrospective study, we evaluated the diagnostic value of magnetic resonance imaging (MRI) cerebrospinal fluid (CSF) flow studies as compared with conventional myelography in patients with syringomyelia.METHODS
From early 2003 to late 2006, 320 patients with syringomyelia underwent cardiac-gated phase-contrast MRI of CSF flow in the brain and spine. We assessed the presence of CSF flow blockage as well as syrinx site, shape, and size. Additional myelography was performed in 8 patients. CSF flow blockage and progressive neurological symptoms or progression of syringomyelia were indications for surgery.RESULTS
Syringomyelia without an obvious cause was found in 125 patients. CSF flow blockage was detected in 33 patients. Seven of these patients underwent cyst wall resection and decompression of the subarachnoid space via a unilateral approach without laminectomy. Myelography revealed CSF flow blockage in only 2 of 8 cases. In the other 6 patients, MRI detected a blockage and surgery revealed arachnoid cysts or webs. Postoperative CSF flow studies revealed free CSF flow in all 10 surgically treated patients. In 6 of these patients, syrinx size was reduced after surgery.CONCLUSION
Myelography should not be the method of choice for the diagnosis of idiopathic syringomyelia. MRI CSF flow studies were found to be more reliable.