Skull and Spine Disorders
Etiology: idiopathic; trauma, back surgery (spinal fusion, laminectomy), meningitis, subarachnoid hemorrhage (spinal tap, epidural steroid injections, difficult epidural blood patch); Pantopaque® myelography (pre 1986) ← inflammatory effect potentiated by presence of blood
M >F ← spinal / epidural anesthesia for delivery
Associated with: syrinx
- chronic low back pain ± radicular symptoms
- par- and hypesthesia, gait disturbance, incontinence, myelopathic symptoms
Location: most easily seen in lumbar region (= cauda equina)
- residual oil-soluble contrast media in dural sac
- intrathecal calcification
Myelo:
- blunting of nerve root sleeves
- blocked nerve roots without cord displacement (⅔)
- streaking + clumping of contrast
CT:
- fusion / clumping (= abnormal distribution) of nerve roots
- intradural pseudomass
- intradural cysts
- empty thecal sac = featureless empty-looking sac with individual nerve roots adherent to wall (final stage)
MR:
- conglomeration of adherent roots centrally within thecal sac:
- thickened nerve roots
- pseudotethering
- empty-sac sign = roots adherent to wall of dural sac:
- deformed / narrowed dural sac ← extra- / intradural scarring
- intrathecal pseudocysts
- soft-tissue mass replacing subarachnoid space
- enhancement of nerve roots (= edema during first 3 months)
Cx: syringomyelia