Posterior and anterior epidural and intradural migration of the sequestered intervertebral disc: Three cases and review of the literature

MRI of difficult discs

Diagnosis of disc herniation is a daily task for radiologists. Although diagnosis is usually straightforward, it may become more difficult due to disc location. Disc herniations in the neural foramen or lateral to it can be overlooked if sagittal images are not obtained far enough laterally, and are often best seen on coronal images. Intradural disc herniations should be recognised preoperatively by their distinctive shape; recognition prepares the surgeon for the need to perform a durotomy and dural repair. Sequestered discs are often lentiform and inconspicuous on sagittal images. They can be missed if axial images are obtained only through the level of the intervertebral disc. Mimics of disc herniation must also be kept in mind when reviewing magnetic resonance imaging (MRI) studies: these include disc osteophyte complex, epidural haematoma, facet joint cyst, and tumours such as meningioma, nerve sheath tumours, and metastases.

Lumbar Intervertebral Disc and Discovertebral Segment. Part 2: An Imaging Review of Pathologic Conditions With Anatomic Correlation

The lumbar intervertebral disc is a complex anatomic structure that can be affected by a number of distinct pathologic processes. Categories of the disease include degenerative changes, subclinical or overt trauma, infectious lesions, inflammatory insults, metabolic disease, and tumors. Abnormalities affecting the intervertebral disc may assume atypical appearances or alterations may as well mimic pathologic processes related to degeneration that can be asymptomatic. Although the imaging findings of degenerative diseases of the vertebral column have been emphasized extensively, the assembly of pathologic conditions associated with the discovertebral segment has not received adequate attention. This manuscript reviews and illustrates a range of abnormalities affecting the discovertebral segment, providing a detailed analysis of postmortem material, in the realm of a close anatomic-imaging correlation. Knowledge of the characteristic morphology and patterns of abnormal conditions affecting the intervertebral disc and discovertebral segment can help radiologists narrow the differential diagnosis in a broad spectrum of disease processes.

Posterior epidural intervertebral disc migration and sequestration: A systematic review

Posterior epidural intervertebral disc migration and sequestration (PEIMS) is a rare and debilitating complication of degenerative disc disease. Radiological differential diagnosis is often challenging, complicating the accurate planning of appropriate treatment strategies. We systematically reviewed the literature on PEIMS, focusing on clinical-radiological features and available treatments. PubMed, Scopus, Web of Science, and Cochrane were searched to include studies reporting clinical data of patients with PEIMS. Clinical characteristics, treatment strategies, and functional outcomes were analyzed. We included 82 studies comprising 157 patients. Median age was 54 years (range, 19-91). PEIMSs occurred spontaneously (49.7%) or acutely in patients with underlying progressive degenerative disc disease (50.3%). The most common symptoms were lower-back pain (77.1%) and radiculopathy (66.2%), mainly involving the L5 nerve root (43.8%). PEIMSs were mostly detected at MRI (93%) and/or CT (7%), frequently located in the lumbar spine (81.5%). Median maximum PEIMS diameter was 2.4 cm (range, 1.2-5.0). Surgical debulking was completed in 150 patients (95.5%), sometimes coupled with decompressive laminectomy (65%) or hemilaminectomy (19.1%). Median follow-up time was 3 months (range, 0.5-36.0). Post-treatment symptomatic improvement was reported in 153 patients (97.5%), with total recovery in 118 (75.2%). All 7 patients (4.5%) who received conservative non-surgical management had total clinical recovery at ≤ 3 months follow-ups. PEIMS is a challenging entity that may severely quality-of-life in patients with degenerative disc disease. Surgical removal represents the gold standard to improve patient's functional status. Spine fusion and conservative strategies proved to be effective in some cases.

Sequestrated Lumbar Disc Herniation Mimicking Spinal Neoplasm

Sequestered disc fragments do not have indistinctive features and often share the clinical and radiological presentation as spinal neoplasms making their diagnosis and treatment a clinical challenge.

We report a rare case of sequestered lumbar disc fragment at the level of L2-L3 in a 70-year-old male who presented to the ER complaining of six years' history of low back pain with acute onset lower extremities weakness for six days, associated with right foot drop. He was admitted for tumor workup as the MRI showed diffuse bone high signal intensity throughout the spine with a soft tissue epidural mass at L2/3, causing severe compression on the cauda equina nerve roots. The patient underwent L2-L3 decompression and fixation, mass excision, multiple open biopsies. Soft tissue biopsy of the mass revealed fibrocartilaginous tissue consistent with the intervertebral disc, while the bone biopsy was diagnostic of acute leukemia. The patient was observed postoperatively with unremarkable complications. He did well with physiotherapy, and there was a remarkable improvement of his right lower extremity power reaching 4/5.

Our case presented a rare phenomenon in which sequestered disc fragments manifested clinically and radiologically as a spinal neoplasm. Vigilant history taking and physical examination are paramount; a physician should be watchful for any red flags that may warrant further investigation such as in our case.

Posterior epidural sequestrated disc presenting with contralateral radiculopathy: a very rare case

INTRODUCTION

Posterior epidural sequestrated disc is a fairly uncommon condition. We report a case of an unusual presentation of posterior epidural migration with contralateral symptoms. We emphasize a high index of suspicion for early recognition and treatment to promote a good neurological recovery.

CASE PRESENTATION

A 58-year-old man with a history of severe back pain for 1 week developed sudden right leg weakness while walking. Neurological examination revealed motor and sensory impairments of the right lower extremities (positive right straight leg raising test, right tibialis anterior grade 2/5, right extensor hallucis longus grade 1/5, decreased pinprick sensation of L4-5 dermatome right side) according to the Standards for Neurological Classification of Spinal Cord Injury as Asia Impairment Scale D. Magnetic resonance images showed an acute disc herniation at L4-5 on the left side, cranially migrated and sequestrated to the posterior epidural area, causing severe compression to the cauda equina in the thecal sac. The patient was successfully treated with surgery (transforaminal lumbar interbody fusion) on an urgent basis. We saw significant neurological recovery on the first day after surgery. Motor power recovery was achieved with a minor deficit at 4 weeks. At the follow-up examination at 3 months, the patient had no residual neurological deficits as Asia Impairment Scale E.

DISCUSSION

Posterior epidural sequestrated disc with contralateral radiculopathy is very rare. This case brings a new presentation of posterior epidural sequestrated disc. To our knowledge, this is the first report of a case with an unusual presentation of contralateral radiculopathy.

Upper Lumbar Intradural Disc Herniation: A Rare Case Report and Etiologic Analysis

Background

Intradural disc herniation (IDH) is a rare type of disc degeneration that infrequently affects the upper lumbar spine. Pre- and intraoperative diagnosis and surgical management of IDH are challenging. The present case study provides insight into these aspects of upper lumbar IDH and discusses possible mechanisms.

Case Description

A 63-year-old female with a history of chronic lower back and leg pain presented with an acute lumbar sprain that had occurred 1 month prior. The pain progressed and spread to the front of the left thigh, which affected her ability to lift her leg when ascending/descending stairs. Sagittal gadolinium-enhanced magnetic resonance imaging (MRI) revealed a disc protruding into the ventral dural sac showing a hawk-beak sign, and the posterior edge of the disc annulus and local posterior longitudinal ligament was broken. Total L2 laminectomy was performed, and the dorsal side of the dural sac was exposed and incised to enable exploration of the ventral side of the dura. We found two free fragments protruding into the inner wall of the dura through the left ventral dura mater defect. After carefully and completely removing the mass, we repaired the defect and performed internal fixation. Postoperative pathologic analysis confirmed that the mass was nucleus pulposus tissue from the degenerated disc. The patient’s pain significantly improved after surgery, and she was able to walk normally at the 1-month follow-up.

Conclusion

Upper lumbar IDH is an extremely rare type of disc degeneration. An enhanced MRI scan can provide diagnostic evidence, but the final diagnosis requires surgical exploration of the path of herniation and pathologic examination of the mass lesion.