Intradural disc herniation at the L1–L2 level: A case report and literature review

Abstract

Background: Why are intradural disc herniations (IDHs) (0.3% of all discs) so infrequent? One explanation has been the marked adherence of the posterior longitudinal ligament (PLL) to the ventral wall of the dura. Variability in symptoms and difficulty in interpreting magnetic resonance (MR) images with/without contrast make the diagnosis of an IDH difficult. Here, we reported a patient with an L1–L2 IDH and appropriately reviewed the relevant literature. Case Description: A 57-year-old male presented with chronic low back and 1 month’s duration of the left thigh pain. The lumbar MR with/without contrast demonstrated an IDH at the L1–L2 level, resulting in spinal cord compression. At surgery, the disc herniation was appropriately resected, the dura was closed, and an interbody fusion with pedicle screw fixation was performed. Postoperatively, the patient clinically improved. Conclusion: IDHs are rare, being seen in only 0.3% of all cases. MR findings, performed with/without contrast, may help signal the presence of an IDH. MR findings include a hypointense structure inside the dura; the “hawk beak” sign (e.g., beak-like mass with ring enhancement at the intervertebral disc space); the Y sign (e.g., ventral dura split into ventral dura and arachnoid by disc material); an abrupt loss of continuity of the PLL; a diffuse annular bulge with a large posterocentral extrusion; and an typical crumbled appearance of disc (e.g., “crumble disc sign”). At surgery, both the extradural and intradural components of the disc must be excised.

Intradural lumbar disc herniations at the L1–L2 level: A case study and literature review

“…Of the approximate 151 cases of IDH reported, 3% occur in the cervical region, 5% in thoracic region, and 92% in the lumbar spine. [1,2,5] e sites most frequently affected include L4-L5 (55%), L3-L4 (16%), L5-S1 (10%) L2-L3, and L1-L2 in descending order. [1] e main theory regarding the formation of IDH is that adhesions occur between the posterior longitudinal ligament (PLL) and the ventral dura due to some local inflammatory processes, leading to spontaneous perforation or rupture.…”

“…[1,2,5] e sites most frequently affected include L4-L5 (55%), L3-L4 (16%), L5-S1 (10%) L2-L3, and L1-L2 in descending order. [1] e main theory regarding the formation of IDH is that adhesions occur between the posterior longitudinal ligament (PLL) and the ventral dura due to some local inflammatory processes, leading to spontaneous perforation or rupture. [1,2,5] Noncontrast and contrast MR findings for IDH On T1-and T2-weighted MR images, IDHs are homogeneously isointense.…”

“…[1] e main theory regarding the formation of IDH is that adhesions occur between the posterior longitudinal ligament (PLL) and the ventral dura due to some local inflammatory processes, leading to spontaneous perforation or rupture. [1,2,5] Noncontrast and contrast MR findings for IDH On T1-and T2-weighted MR images, IDHs are homogeneously isointense. Notably, Hidalgo-Ovejero et al [5] found that gas within the spinal canal was associated with IDH.…”

“…We identified only seven cases of IDH involving the L1-L2 level. [1,2,3,6,7,8] Here, we presented a 65-year-old female with a L1-L2 IDH accompanied by caudal migration. IDH was anticipated based on the combined MR findings of large obstructive mass at the L1-L2 level and the positive "hawk-beak sign. "…”

Spina Bifida Occulta with Bilateral Spondylolysis at the Thoracolumbar Junction Presenting Cauda Equina Syndrome

“…This patient required immediate decompression and fusion surgery because of neurological deficits due to cauda equina syndrome. Several cases of cauda equina syndrome caused by L1-2 disc hernia have been reported [9,10]. In this case, because of the disruption of the posterior elements caused by SBO and spondylolysis, we performed posterior lumbar interbody fusion at L1-2.…”