Idiopathic spinal cord herniation at two separate zones of the thoracic spine: the first reported case and literature review

Unveiling the Current Understanding of Idiopathic Spinal Cord Herniation: A Systematic Review

Background

Idiopathic spinal cord herniation (ISCH) is a rare condition that is characterized by ventral herniation of the spinal cord through a defect in the dura mater into the epidural space, with no identifiable cause. ISCH is frequently underdiagnosed, and the information available in case reports is limited. To provide an overview of the clinical manifestations and diagnosis of this condition, this study aims to conduct a review of reported cases of ISCH.

Methods

A literature review was carried out using seven databases. The search was conducted using the keywords "Idiopathic spinal cord herniation" OR "Idiopathic Ventral Spinal Cord Herniation" AND "Case report" OR "case series."

Results

A total of 92 relevant papers reporting 224 cases, besides the index case, were determined. Of the cases, 58.5% were females and the mean age was 50.7 (SD 13.2) years. Symptoms, diagnoses, and outcomes were similar between genders. The most common clinical signs included motor symptoms (82.6%), instability (61.3%), hypoesthesia (59.2%), and disturbance of thermal sensitivity (47.3%). Brown-Séquard syndrome was observed in 27.2% of the cases, and surgical treatment was employed in 89.7% of the cases.

Conclusions

ISCH is a pathology that is principally treated with surgical approach. This study provides valuable insights into the clinical manifestations and diagnosis of ISCH, which can aid in the early recognition and treatment of this rare condition.

Thoracic Anterior Spinal Cord Herniation: Treatment and Prognosis Outcome of Seven Patients

BACKGROUND

This study aimed to investigate the diagnosis and treatment of thoracic anterior spinal cord herniation, a rare condition.

METHODS

Clinical data of 7 patients diagnosed with thoracic anterior spinal cord herniation were analyzed. All patients were diagnosed with a complete preoperative examination and scheduled for surgical treatment. In addition, regular follow-up was performed after the surgery, and the operation's efficacy was evaluated according to clinical symptoms, imaging findings, and improvement in neurologic function.

RESULTS

All patients underwent spinal cord release with an anterior dural patch. Notably, no severe postoperative surgical complications were observed. All patients were followed up for 12-75 months, with an average duration of approximately 46.5 months. Post-operative pain symptoms were controlled, neurological dysfunction and related symptoms improved to varying degrees, and anterior spinal cord herniation did not recur. The modified Japanese Orthopedic Association score at the last follow-up was significantly higher than the preoperative score.

CONCLUSIONS

Clinicians should avoid misdiagnosing patients with thoracic anterior spinal cord herniation with intervertebral disc herniation, arachnoid cysts, and other related diseases, and patients should undergo surgical treatment as early as possible. In addition, surgical treatment can protect the neurologic function of patients and effectively prevent the aggravation of clinical symptoms.

Thoracic ossification of the ligamentum flavum causing Brown-Séquard syndrome: a case report and literature review

Brown-Séquard syndrome (BSS) has many etiologies, including penetrating trauma, extramedullary tumors, and disc herniation. However, thoracic ossification of the ligamentum flavum (OLF) is an extremely rare cause of this syndrome. A 46-year-old woman with motor weakness in her right lower extremity and urinary retention was admitted to our department. Based on the results of physical examination, computed tomography, and magnetic resonance imaging, a diagnosis of BSS with OLF was considered. The patient underwent urgent conservative treatment. BSS is a rare condition characterized by hemisection or hemicompression of the spinal marrow. The herein-described case of incomplete BSS due to OLF responded to conservative treatment. However, the successful nonoperative management of this case is insufficient evidence to consider it as the standard of care. Therefore, emergency laminectomy decompression remains the standard of care for BSS.

Novel Strategy of Ventral Dural Repair for Idiopathic Thoracic Spinal Cord Herniation: Report of Outcomes and Review of Techniques

BACKGROUND

Idiopathic ventral thoracic spinal cord herniation is a rare condition that usually presents with progressive myelopathy or Brown-Séquard syndrome. More than 100 cases have been reported with significant variance in surgical treatment strategies and likewise, significant variance in patient outcomes. Although laminectomy has often been used, to date, there is no consensus regarding the optimal surgical approach or strategy for ventral dural repair.

OBJECTIVE

To report and illustrate a novel approach to repair the ventral dural defect with more than 2 yr of clinical follow-up. The specific approach and graft used are both detailed.

METHODS

A retrospective chart review of all known cases of idiopathic spinal cord herniation at the Cleveland Clinic over the last 15 yr was performed. Postoperative outcome scores (including the Japanese Orthopedic Association score, European Myelopathy score, and Nurick) were calculated preoperatively and postoperatively.

RESULTS

A total of 5 patients were identified. Four of five patients improved clinically after surgery and 1 patient remained unchanged at last follow-up (average 23.2 mo, range 12-60 mo). There were no complications. All patients had postoperative magnetic resonance imaging demonstrating realignment of the spinal cord and no recurrence of tethering.

CONCLUSION

A unilateral dorsolateral, transpedicular approach combined with laminectomy provides excellent exposure for ventral or ventrolateral dural defects associated with idiopathic spinal cord herniation and minimizes spinal cord manipulation. A collagen matrix graft used as an onlay between the spinal cord and ventral dural defect is a safe and effective option for ventral dural repair.

Understanding Idiopathic Spinal Cord Herniation - A Comprehensive Review of Imaging and Literature

Idiopathic spinal cord herniation (ISCH) is displacement of spinal cord through a dural or arachnoidal defect. Most patients present with back pain or myelopathy, paresthesia, and sensory or motor weakness. Imaging findings include anterior displacement of the cord with possible kink, no filling defect on CT myelography, and no restricted diffusion/mass lesion on magnetic resonance imaging. Abrupt kink in the spinal cord or widened cerebrospinal fluid (CSF) space can be caused by a variety of reasons. The differential considerations include arachnoid web, intradural extramedullary epidermoid or arachnoid cyst, abscess or cystic schwannoma. We discuss the features, imaging, differentials, and treatment of ISCH as a rare cause of such kink in the cord. While reading such cases, a radiologist should include the location, segments involved, cord signal abnormality, visible defect, scalpel sign or C–sign, ventral cord kink, nuclear trail sign, the ventral CSF space preservation, or obliteration and the type.

Disc herniation, occult on preoperative imaging but visualized microsurgically, as the cause of idiopathic thoracic spinal cord herniation

Idiopathic spinal cord herniation (ISCH) through an anterior dural defect is rare and the cause is uncertain. Recently, through interpreting imaging studies, disc herniation was proposed to be a major cause for ISCH. We describe the case of a 50-year-old woman with progressive myelopathy who was diagnosed with a thoracic spinal cord herniation. Microsurgical exploration revealed an anterior vertical dural defect and a small concomitant disc herniation, occult on the preoperative imaging, which caused the dural defect and led to ISCH. This intraoperative finding corroborates the emerging notion that disc herniation is the underlying cause of ISCH.

The Pathogenesis of Ventral Idiopathic Herniation of the Spinal Cord: A Hypothesis Based on the Review of the Literature

Idiopathic ventral herniation of the spinal cord (SC) is not often encountered in daily practice. Its clinical prevalence, however, will increase through increasing awareness and more frequent use of MRI. A clear explanation of its pathophysiology has never been formulated. It was hypothesized that the findings during surgery might indicate the real causative mechanism. An extensive literature search was performed, using Embase, PubMed, and Google Scholar. Titles and abstracts were screened by two investigators, using strict inclusion and exclusion criteria. Reference lists of the full paper versions of each included article were checked. The following data were registered for the articles included: age, gender, level of herniation, relation to intervertebral disk, duration of symptoms, findings from surgery, and outcomes. Nine cases treated at our department were added. A total of 117 articles reporting on 259 patients were included. Including our cases, 268 patients were reviewed. Females outnumbered males (160/100). The mean age was 51.3 ± 12.0 years. In 236 patients, the duration of symptoms was reported: 55.5 ± 55.6 months. In 178 patients, the intraoperative findings for the herniated part of the SC were not mentioned. In 59 patients, a tumor-like extrusion was seen, without any alteration to the SC. Deformation of the SC itself was never observed. Biopsies of these structures were without clinical consequence. Based on the intraoperative findings reported in literature and the cases presented, acquired causes, such as trauma and erosion of the dura due to a herniated disk, were not plausible. We hypothesize that a non-functioning appendix to the SC can only develop during an early embryologic phase, in which several layers separate. We propose renaming this entity as congenital transdural appendix of the SC.

Idiopathic spinal cord herniation: consideration of its pathogenesis based on the histopathology of the dura mater

INTRODUCTION

We present a patient with idiopathic spinal cord herniation (ISCH) whose dura mater was histopathologically examined to elucidate its pathogenesis.

CASE REPORT

A 33-year-old previously healthy man presented with progressive walking difficulty, spasticity of the right lower leg, and hyperesthesia below the right chest. Neuroimaging revealed right ventral displacement of the spinal cord at T5-6. The diagnosis was ISCH and he underwent release of the herniation from the ventral dural opening. Dural biopsy at the edge of the ventral opening and in the dorsal durotomy was performed. Postoperatively, his gait was improved. Histopathological examination of the ventral dural specimen showed non-specific degeneration, i.e., loose arrangements of collagen fibers, edematous changes, minor inflammatory cell infiltration, and angiogenesis. The specimen from the dorsal durotomy was normal.

CONCLUSION

It is unclear whether the observed degeneration besides the ventral opening was the primary cause of ISCH or reflected secondary changes resulting from cumulative damage due to pulsation of the herniated spinal cord. However, the degeneration limited to the ventral opening suggests that ISCH was a local event in an individual with a normal dural theca.

A New Classification for Pathologies of Spinal Meninges, Part 1: Dural Cysts, Dissections, and Ectasias

BACKGROUND: The clinical significance of pathologies of the spinal dura is often unclear and their management controversial.

OBJECTIVE: To classify spinal dural pathologies analogous to vascular aneurysms, present their symptoms and surgical results.

METHODS: Among 1519 patients with spinal space-occupying lesions, 66 patients demonstrated dural pathologies. Neuroradiological and surgical features were reviewed and clinical data analyzed.

RESULTS: Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery.

CONCLUSION: The majority of dural pathologies involving root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Type I and type II pathologies were treated with good long-term results occluding their dural defects, while ectasias of the dural sac (type III) were managed conservatively.

Spinal cord herniation repair with microstaples: case report

Idiopathic spinal cord herniation (ISCH) is a relatively rare and frequently misdiagnosed condition. It preferentially affects women and causes progressive thoracic myelopathy that presents as a Brown-Séquard syndrome or as spastic paraparesis. Although its etiology and pathogenesis are controversial, ISCH is characterized by the presence of an anterior dural defect that allows the incarceration of a segment of the cord. Typically, a C-shaped ventral displacement and kinking of the cord are visible on sagittal MRI. Surgery aimed at stopping or reversing myelopathic symptoms is usually recommended for symptomatic patients. Surgical options include reduction of the hernia and direct suturing, or enlargement of the dural defect, with or without patching. Suturing under the cord in a very tight space can be troublesome and may lead to neurological deterioration. The authors present the case of a symptomatic ISCH in which nonpenetrating titanium microstaples were used to close the dural defect after cord reduction. The patient experienced a good outcome, and the follow-up MRI study showed adequate cord repositioning and stability of the suture. The use of microstaples, which allows for an easier and faster dural closure than conventional suturing, is a novel technical adjunct that has not been previously reported for this condition. In addition, microstaples produce minimal metallic artifact that does not hinder the quality of follow-up MR images.

Minimally Invasive Direct Thoracic Interbody Fusion (MIS-DTIF): Technical Notes of a Single Surgeon Study

Background

Minimally invasive direct thoracic interbody fusion (MIS-DTIF) is a new single surgeon procedure for fusion of the thoracic vertebrae below the scapula (T6/7) to the thoracolumbar junction. In this proof of concept study, we describe the surgical technique for MIS-DTIF and report our experience and the perioperative outcomes of the first four patients who underwent this procedure.

Study design/setting

In this study we attempt to establish the safety and efficacy of MIS-DTIF. We have performed MIS-DTIF on six spinal levels in four patients with degenerative disk disease or disk herniation. We recorded surgery time, blood loss, fluoroscopy time, complications, and patient-reported pain.

Methods

Throughout the MIS-DTIF procedure, the surgeon is aided by biplanar fluoroscopic imaging and electrophysiological monitoring. The surgeon approaches the spine with a series of gentle tissue dilations and inserts a working tube that establishes a direct connection from the outside of the skin to the disk space. Through this working tube, the surgeon performs a discectomy and inserts an interbody graft or cage. The procedure is completed with minimally invasive (MI) posterior pedicle screw fixation.

Results

For the single level patients the mean blood loss was 90 ml, surgery time 43 minutes, fluoroscopy time 293 seconds, and hospital stay two days. For the two-level surgeries, the mean blood loss was 27 ml, surgery time 61 minutes, fluoroscopy time 321 seconds, and hospital stay three days. We did not encounter any clinically significant complications. Thirty days post-surgery, the patients reported a statistically significant reduction of 5.3 points on a 10-point sliding pain scale.

Conclusions

MIS-DTIF with pedicle screw fixation is a safe and clinically effective procedure for fusions of the thoracic spine. The procedure is technically straightforward and overcomes many of the limitations of the current minimally invasive (MI) approaches to the thoracic spine. MIS-DTIF has the potential to improve patient outcomes and reduce costs relative to the current standard of care. We are currently expanding this study to a larger cohort and recording long term outcomes and costs.

Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation.

Spinal cord herniation following cervical meningioma excision: a rare clinical entity and review of literature

BACKGROUND

Spinal cord herniation following surgery is an extremely uncommon clinical condition with very few reports in published literature. This condition usually occurs as a spontaneous idiopathic phenomenon often in the thoracic spine or following a scenario of post traumatic spinal cord/nerve root injury. Rarely has it been reported following spinal cord tumor surgery.

PURPOSE

To document a case of cervical spinal cord herniation as a late onset complication following spinal cord tumor surgery with an atypical presentation of monoparesis.

DESIGN

Case report.

METHODS

We describe the clinical presentation, operative procedure, post operative outcome and review of literature of this rare clinical condition.

RESULTS

A 57-year-old man presented with right upper limb monoparesis due to a spinal cord herniation 6 years after a cervical intradural meningioma excision. The patients underwent surgery to reduce the herniation and duroplasty with subsequent complete resolution of symptoms.

CONCLUSIONS

Spinal cord herniation must be considered as differential diagnosis in scenarios of spinal cord tumor excision presenting with late onset neurological deficit. These cases may present as paraparesis, Brown-sequard syndrome and rarely as in our case as monoparesis.

Symptomatic thoracic spinal cord herniation: case series and technical report

BACKGROUND AND IMPORTANCE

Idiopathic spinal cord herniation (ISCH) is an uncommon condition located predominantly in the thoracic spine and often associated with a remote history of a major traumatic injury. ISCH has an incompletely described presentation and unknown etiology. There is no consensus on the treatment algorithm and surgical technique, and there are few data on clinical outcomes.

CLINICAL PRESENTATION

In this case series and technical report, we describe the atypical myelopathy presentation, remote history of traumatic injury, radiographic progression, treatment, and outcomes of 5 patients treated at Washington University for symptomatic ISCH. A video showing surgical repair is presented. In contrast to classic compressive myelopathy symptomatology, ISCH patients presented with an atypical myelopathy, characterized by asymmetric motor and sensory deficits and early-onset urinary incontinence. Clinical deterioration correlated with progressive spinal cord displacement and herniation observed on yearly spinal imaging in a patient imaged serially because of multiple sclerosis. Finally, compared with compressive myelopathy in the thoracic spine, surgical treatment of ISCH led to rapid improvement despite a long duration of symptoms.

CONCLUSION

Symptomatic ISCH presents with atypical myelopathy and slow temporal progression and can be successfully managed with surgical repair.

Surgical Management of a Patient With Thoracic Spinal Cord Herniation

BACKGROUND AND IMPORTANCE:

Thoracic spinal cord herniation (TSCH) is rare and likely underdiagnosed. It is characterized by ventral herniation of the spinal cord through a dural defect, effacement of the anterior subarachnoid space, and increased posterior subarachnoid space. We present here a case of TSCH diagnosed and surgically treated at Barrow Neurological Institute, along with supplemental intraoperative video.

CLINICAL PRESENTATION:

A 61-year-old man with a history of progressive myelopathy causing left lower-extremity weakness with associated numbness, impaired gait, foot drop, incontinence, and sexual impotence was referred without any previous treatment. Computed tomographic myelography and magnetic resonance imaging of the thoracic spine showed ventral spinal cord herniation at T3-T4. Neurological monitoring was recorded preoperatively and intraoperatively. The patient underwent left-sided posterolateral exploration via T3-T4 laminectomies and costotransversectomy for intradural cord release/detethering of the spinal cord with additional superior and inferior extension and repair of the dural defect. Arthrodesis was not considered necessary. After cord release, motor evoked potentials showed immediate improvement from baseline. Dural duplication was considered the cause of TSCH in this case. Total reduction of herniation was evident in postoperative images. The postoperative course was uneventful, and at the last follow-up, the patient had regained ambulation and sphincter control.

CONCLUSION:

Anterior displacement of the thoracic spinal cord should elicit consideration of herniation to prevent misdiagnosis and inadequate surgery. Surgical cord release and enlargement of the dural defect are safe and associated with good clinical outcomes.

Spinal cord herniation after resection of cervical spinal neurofibroma with a unique presentation

BACKGROUND CONTEXT

Spinal cord herniation (SCH) is a very rare condition. It was first reported in the lumbar spine in 1974. Thereafter, cases were reported in the thoracic and cervical spine occurring either spontaneously or after vertebral fracture, nerve root avulsion, and trauma surgery.

PURPOSE

There is only one recorded case of SCH after tumor surgery. In this article, we reported the second case.

STUDY DESIGN

We described the original surgical procedure, the clinical presentation, the operative repair, and the postoperative course.

METHODS

No funding was required for this case report.

RESULTS

The patient was a 56-years-old man, who presented with SCH 5 years after subtotal excision of a cervical neurofibroma. He presented with right upper monoparesis.

CONCLUSIONS

To our knowledge, this presentation has not been reported previously in literature.