Intradural disc herniation at the L2/3 level: a case report and literature review

Abstract

Background: Intradural lumbar disc herniation (ILDH) is special type of lumbar disc herniation in which the lumbar nucleus pulposus prolapses and enters the dura mater. ILDHs comprise 0.04-0.33% of all herniated discs. In most cases, the diagnosis could not be confirmed preoperatively by identifying the typical features of ILDH in radiological evaluation. In the current report, we present a case of ILDH at lumbar 2/3 level and discuss the clinical presentations, typical imaging features, treatments, and outcomes.Case Description: We describe a rare case of ILDH. The patient was a 65-year-old man with pain in waist and back, and with bilateral radiating pain of lower extremities and fatigue for more than 2 weeks.Magnetic resonance imaging (MRI) revealed a large round, low-density mass at lumbar 2/3, which was easily mimicked as an intradural spinal tumor lesion. While enhanced MRI showed the typical rim enhancement sign and "Hawk beak" sign. Due to progressive decrease in muscle strength in both lower limbs, posterior microscopically assisted laminectomy, dural incision of the lumbar 2/3 was performed. Pathological examination revealed degenerated fibrous connective tissue and cartilage tissue. The patient's lower back pain and radiating pain and numbness of both legs improved remarkably postoperatively, and he became asymptomatic at 3 months and 1-year postoperatively.Conclusions: ILDH is a rare intervertebral disc herniation in clinical practice. The pathogenesis of ILDH may be related to aseptic inflammatory edema, closely fixing of ventral dura and the posterior longitudinal ligament, repeated mechanical action and chemical corrosion. Typical rim enhancement sign, "Hawk beak" sign and "Y" sign are important features of MRI in diagnosing ILDH, and intraspinal gas is also helpful in computed tomography (CT) diagnosis of ILDH. Prompt microscopically assisted laminectomy, dura mater incision to remove the intradural disc, pedicle screw fixation regardless of fusion, surgical results are usually favorable. We also reviewed the literature and discussed the epidemiology, potential pathogenesis, diagnosis, treatment and poor prognostic factors of ILDH.

Herniating Intradural Disc at Lumbar L4-L5 Level: A Case Report

“…Hence, the scarcity of literature on spectrum of such diseases warrants the need for discussions over rare cases from all over the globe. The common age group reported for ILDH is 60 years or older population, but a few young patients aged 21 and 30 years were also documented, which correlates with the patient reported in our case as well [6,[8][9][10][11][12][13].…”

“…This point warrants the need for more advanced and specific imaging modalities for better pre-operative planning of such cases. Pathological findings from previous reports also support the degenerative findings of the removed disc in our case [9,11].…”

“…Prior literature also reports no neurological deficit post-surgery, which corresponds positively to our patient's outcome [8,11,12].…”

Seated Straight Leg Raise Test; Sensitivity & Specificity in Patients with Disc Herniation at Lumbosacral Interface Using MRI as A Gold Standard

“…Accurate diagnosis remains challenging, particularly for conditions like intradural lumbar disc herniation. Wen et al ( 2022) emphasize the need for specific imaging features for correct diagnosis, highlighting the complexities in identifying and treating lumbosacral disc herniations (21). While the SLR test, particularly in its modified form, is a valuable tool for assessing neurosensitivity, it does not fully explain lumbar disc herniation.…”