IDH correspond to a rare presentation of a common pathology, comprising ~0.28% of all disc herniations 2.
Symptoms are indistinguishable from other types of disc hernias. A higher incidence of cauda equina syndrome has been reported when compared to extradural hernias 2.
Intradural disc herniations represent a challenge for preoperative diagnosis, with most of the cases only confirmed at surgery.
Although CT has a known limitation to assess the dural sac and spinal cord, when gas is present in the degenerated intervertebral disc space (vacuum phenomenon), this can migrate to the herniated mass and delineate the intradural component of a hernia 3.
The intradural herniated disc may be delineated protruding into the dural sac. However, it can be difficult to differentiate from an intradural tumor. Postcontrast images will delineate an incomplete ring enhancement (chronic granulation tissue
and peripheral neovascularization), helping in distinguishing it from those tumors 3.
- 1. Fardon DF, Williams AL, Dohring EJ et-al. Lumbar disc nomenclature: version 2.0: Recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology. Spine J. 2014;14 (11): . doi:10.1016/j.spinee.2014.04.022 - Pubmed citation
- 2. Ducati LG, Silva MV, Brandão MM et-al. Intradural lumbar disc herniation: report of five cases with literature review. Eur Spine J. 2013;22 Suppl 3 (S3): S404-8. doi:10.1007/s00586-012-2516-4 - Free text at pubmed - Pubmed citation
- 3. Kobayashi K, Imagama S, Matsubara Y et-al. Intradural disc herniation: radiographic findings and surgical results with a literature review. Clin Neurol Neurosurg. 2014;125: 47-51. doi:10.1016/j.clineuro.2014.06.033 - Pubmed citation
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