Intradural Herniated Lumbar Disc

Abstract

UPTURE of the intervertebral disc in the lumbar spine most often occurs to one or the other side of the strong posterior longitudinal ligament. Rarely the central part of the ligament itself is perforated. Even more rare is the observation that the disc material has ruptured through the anterior aspect of the spinal dura and is displaced intrathecally. Only nine such cases have been reported. ~,3-7 Two patients with intradural disc herniation recently treated in the Neurosurgical Department of Ullevfil Hospital provided the stimulus for an anatomical investigation of the relation between the spinal dura and the posterior longitudinal ligament in the lower lumbar region.

Intradural lumbar disc herniation: report of five cases with literature review

“…Several authors have found in autopsies the presence of adhesions between the ventral dural sheath and the posterior longitudinal ligament (PLL), which are loose in most cases. However, in some cases, these adhesions may be extremely resistant, unable to be separated through sharpless dissection [6,7], being an important predisposing factor. Such adhesions occur more often in L4-L5 space, which justifies a higher incidence of intradural disc herniations at this level, being more prevalent in patients with history of previous lumbar pain [6].…”

“…Clinically, there is a higher incidence of cauda equina syndrome (CES) in IDH than in extradural herniations [3,6,7] and despite the advance of present neuroimaging techniques, it is not yet possible to establish accurately whether a disc herniation is located intradurally [1]. The diagnosis is only confirmed at surgical field in most cases.…”

“…The IDH etiopathogenesis is unclear, but some surgical and anatomopathological findings indicate a possible attachment between the anterior dura and the annulus fibrosus, conditions which would facilitate the nucleus pulposus herniation into the dural sac [3,4,6].…”

Voluminous Free Disk Fragment Mimicking an Extradural Tumor

“…4) MR imaging with contrast medium is useful to differentiate herniated disc from tumors and other epidural lesions, as the non-enhancing disc fragment is commonly associated with peripheral enhancement. Herniated disc fragment rarely includes central enhancement, a finding attributed to vascular granulation tissue infiltrating the fragment, 2) but is never associated with enhancement of the spinal meninges, an early characteristic finding of neoplastic lesions such as lymphoma, neurofibroma, neuroblastoma, mesothelioma, and lung cancer. 4) In our case, the lesion appeared homogeneously hyperintense on T 2 -weighted MR imaging (Fig.…”

“…Non-typical sequestrated disc herniations are extremely rare (0.4%) and were previously only identified during surgery, 2,4) but even after the introduction of high resolution magnetic resonance (MR) imaging are frequently misinterpreted as neoplastic masses. 1,4) No particular symptoms or signs are known to allow differentiation between atypical hernias and spinal tumors.…”