Syringomyelia is a cystic cavitation of the spinal cord associated with Chiari I malformation (70%) or basilar invagination (10%) or tumor. It may be a post-traumatic condition. There are 2 main forms: communicating with the central canal or subarachnoid spaces (Chiari I malformation); non communicating (trauma, tumors). Non traumatic syringomyelia usually presents between the third and sixth decades of life with a prevalence of 8.4 cases/100,000 populations.
Clinical presentation is variable: weakness, atrophy, loss of pain & temperature sensation with preserved touch and joint position sense; pain (unrelieved with analgesics), numbness, increased motor deficit, autonomic dysreflexia, ascending sensory level, depressed tendon reflexes. Post-traumatic syringomyelia has a late presentation following spinal cord injury. Mean latency to symptoms and diagnosis following spinal cord injury is 9 years and 2.8 years, respectively.
Best imaging tool: MR Imaging. MRI findings: T1WI - Hypointense spinal cord cleft in sagittal and axial images; T2WI - hyperintense intramedullary cavity +/- adjacent gliosis, myelomalacia (arachnoidal adhesions, cord tethering or edema); T1 + contrast - non-enhancing cavity (enhancement in inflammatory or neoplastic lesions); 2D MR cine phases contrast a CSF flow study.
Differential diagnosis: ventriculus terminalis; cystic spinal cord tumor; myelomalacia.
Treatment: posterior decompression in Chiari I malformation; shunt (Heyer-Schulte-Pudenz system) in subarachnoid space (complication rate = 16%; clinical stabilization rate = 54% at 10 years); cord transection - in complete injuries only (post-traumatic syringomyelia); lyse adhesions. Low Cerebro-spinal fluid diastolic flow velocity is present after successful surgery.
Clinical presentation is variable: weakness, atrophy, loss of pain & temperature sensation with preserved touch and joint position sense; pain (unrelieved with analgesics), numbness, increased motor deficit, autonomic dysreflexia, ascending sensory level, depressed tendon reflexes. Post-traumatic syringomyelia has a late presentation following spinal cord injury. Mean latency to symptoms and diagnosis following spinal cord injury is 9 years and 2.8 years, respectively.
Best imaging tool: MR Imaging. MRI findings: T1WI - Hypointense spinal cord cleft in sagittal and axial images; T2WI - hyperintense intramedullary cavity +/- adjacent gliosis, myelomalacia (arachnoidal adhesions, cord tethering or edema); T1 + contrast - non-enhancing cavity (enhancement in inflammatory or neoplastic lesions); 2D MR cine phases contrast a CSF flow study.
Differential diagnosis: ventriculus terminalis; cystic spinal cord tumor; myelomalacia.
Treatment: posterior decompression in Chiari I malformation; shunt (Heyer-Schulte-Pudenz system) in subarachnoid space (complication rate = 16%; clinical stabilization rate = 54% at 10 years); cord transection - in complete injuries only (post-traumatic syringomyelia); lyse adhesions. Low Cerebro-spinal fluid diastolic flow velocity is present after successful surgery.
References
- Ross JS, Brant-Zawadzki M, Moore KR, et al.. Diagnostic Imaging Spine. First edition - Amirsys - Elsevier Saunders - 2004.
- Handbook of Neurosurgery - sixth edition - Mark S. Greenberg - ed. Thieme.
