Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
Sign up to receive an email alert when a new Case of the Week is posted.
February 11, 2016
Dorsal Thoracic Arachnoid Web
- Background:
- Arachnoid webs are intradural extramedullary transverse bands causing indentation on the dorsal surface of the spinal cord, with predilection for the upper thoracic spine.
- Clinical Presentation:
- Upper and lower extremity weakness, numbness and back pain
- Key Diagnostic Features:
- Focal dorsal indentation of the spinal cord, the “scalpel sign” (scalpel with the blade pointing dorsally).
- The ventral surface of the cord is not deformed.
- The widened CSF space posterior to the cord opacifies with contrast on myelographic studies. The spinal cord adjacent to the web may show increased T2 signal which may progress to syrinx formation.
- Differential Diagnosis:
- Spinal cord herniation: Deformity of the ventral cord surface with cord protrusion through anterior dural defect
- Intraspinal dorsal arachnoid cyst: Smooth scalloping of the cord with no or delayed opacification on myelography
- Treatment:
- Surgical lysis of the web
Current Issue
Case Collections
