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

Idiopathic thoracic spinal cord herniation into the vertebra progressing for 3 years

A 43-year-old, previously healthy man experienced a decreased sensation in the left lower extremity without preceding spinal trauma. At presentation, the patient exhibited slight motor weakness in the left lower extremity, in addition to decreased pain sensation below the ipsilateral T7. Spinal magnetic resonance imaging (MRI) revealed abnormal findings consistent with idiopathic thoracic spinal cord herniation (ITSCH) at the T5/6 level. Computed tomography (CT) revealed a small vertebral erosion at the lower T5. The patient's symptoms gradually progressed over the next 3 years. MRI revealed marked lateral elongation of the cord at the T5/6 and apparent intravertebral cord herniation. The patient underwent ITSCH reduction through T5-6 laminectomies. The herniated cord was vertically long with a bulbous rostral part. Successful ITSCH reduction was achieved and the patient's postoperative course was uneventful. ITSCH is a progressive pathology that requires prompt surgical reduction. Certain ITSCHs may be complicated by intravertebral cord herniation.

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.

Spinal Anterior Dural Dissection: Moving From Differential to Unifying Diagnosis

BACKGROUND AND OBJECTIVES

Cerebrospinal fluid (CSF) collections extending longitudinally at the anterior aspect of the spinal dura have been reported in association with various conditions and under multiple names. The aim of this study was to report cases associated with brachial amyotrophy (BA) and examine its relationship with other clinical variants.

METHODS

We conducted a retrospective cohort study including patients who presented with a motor deficit of the upper limbs and an anterior interdural CSF collection on spinal MRI. We performed a systematic review of the literature to include cases revealed by BA.

RESULTS

Seven patients presenting with BA and a confirmed dural dissection on spinal MRI were included. All patients were male with a slowly progressing history of asymmetrical and proximal motor deficit of the upper limbs. Chronic denervation affecting mostly C5 and C6 roots was found on electroneuromyography. Spinal MRI demonstrated an anterior CSF collection dissecting the interdural space and exerting a traction on cervical motor roots. Dynamic computed tomography myelogram localized the dural defect every time it was performed (4/7 cases), and surgical closure was possible for 3 patients, leading to resolution of the collection. Literature review yielded 18 other published cases of spinal dural dissections revealed by BA, including 4 in association with spontaneous intracranial hypotension and 4 others in association with superficial siderosis.

CONCLUSION

We propose a unifying diagnosis termed "spinal anterior dural dissection" (SADD) to encompass spinal dural CSF collections revealed by BA (SADD-BA), spontaneous intracranial hypotension (SADD-SIH), or superficial siderosis (SADD-SS).

Case report: A vertebral bone spur as an etiology for spinal cord herniation: case presentation, surgical technique, and review of the literature

Objective

The pathophysiology of idiopathic spinal cord herniation remains unknown. However, several different factors have been postulated, such as congenital causes (ventral dura mater duplication, preexisting pseudomeningocele, or other congenital dural defects), inflammation, remote spinal trauma, or thoracic disc herniation. Herein, the diagnosis and surgical treatment of a patient with spinal cord herniation caused by an intraspinal bone spur is presented along with a relevant literature review.

Case presentation

A 56-year-old male patient presented with a non-traumatic Brown-Sequard syndrome persisting for over 1 year. A magnetic resonance imaging of the spinal axis revealed a ventral spinal cord displacement in the level of T 6/7. A supplementary thin-sliced computed tomography of the spine revealed a bone spur at the same level. For neurosurgical intervention, T 6 and T 7 laminectomy was performed. The cranial and caudal end of the right paramedian ventral dural defect was visualized and enlarged. Following extradural spinal cord mobilization by denticulate ligament transection, the spinal cord was finally released. The spinal cord was rotated and the ventral closure of the dural defect was performed by continuous suture. The patient recovered from surgery without additional deficits. The patient's postoperative gait, sensory, and motor function deficits improved, and further neurological deterioration was prevented.

Conclusion

Since the first description of spinal cord herniation by Wortzman et al. in 1974, approximately 260 cases have been reported in the literature. In addition to other causes, intraspinal bone spur is a possible cause of spinal cord herniation.

Remarkable improvement of neurological deficits after surgery in patients with Idiopathic spinal cord herniations. The impact of peroperative neuromonitoring. Case reports

Introduction

Chronic Idiopathic Spinal Cord Herniation (ISCH) is a very rare spinal cord deformation occurring predominantly in thoracic levels. ISCH lead to progressive myelopathy, spastic paraparesis and Brown Séquard syndrome.

Research question

We want to hypothesize that a) the herniated segment can regain its function after untethering despite long-term and complete neurologic dysfunction. b) Intraoperative Electrophysiologic Monitoring (IOEPM) may identify intraoperative changes by monitoring specific neural pathways confirming the efficacy of the intervention in the forthcoming cases.

Material & method

It is a retrospective review of data of two cases prospectively collected showing improvement of neurological deficit in cases of ISCH in thoracic levels. We describe two patients with progressive neurological deficits due to ISCH who underwent surgery using electrophysiologic monitoring and have been followed to reach remarkable clinical improvement.

Results

The spastic paraparesis of the first case improved remarkably after surgery. Complete foot drop of the other case, persistent for 7 months before intervention, improved after the release of the herniated segment of the cord. Peroperative electrophysiological monitoring did not show changes during surgery.

Conclusion

We want to hypothesize that the herniated segment can regain its function after untethering despite long-term and complete neurologic dysfunction. Intraoperative Electrophysiologic Monitoring (IOEPM) may confirm the efficacy of the intervention in the forthcoming cases.

Idiopathic spinal cord herniation at the cervicothoracic junction level presenting with unilateral sensory symptoms

Idiopathic spinal cord herniation (ISCH) most commonly occurs through a ventral dural defect at the midthoracic levels with a predilection to affect middle-aged females. It can have various presentations, the most common of which are Brown-Séquard syndrome and spastic paraparesis. Due to its rarity in clinical practice, the diagnosis of ISCH can be challenging to physicians unfamiliar with this entity. We report an exceedingly rare case of ISCH at the C7-T1 intervertebral disc level in a 44-year-old male presenting with eight months of isolated unilateral sensory symptoms. The diagnosis was made based on the findings on the patient's magnetic resonance imaging of the spinal cord, including the presence of an extradural cerebrospinal fluid collection. Surgical reduction of the herniated segment and patching of the dural defect resulted in a remarkable clinical improvement beginning in the immediate postoperative period. Follow-up MRIs showed no sign of reherniation, and the patient remained asymptomatic after one year of follow-up. Early diagnosis and surgical intervention led to an excellent early outcome in this case. However, long-term follow-up is necessary to monitor for reherniation and relapse of the symptoms in ISCH patients.

Case Report: Idiopathic Spinal Cord Herniation: An Overlooked and Frequently Misdiagnosed Entity

Background

Idiopathic spinal cord herniation is an extremely rare entity that is characterized by protrusion of the spinal cord through a defect in the ventral dura. Due to the paucity of enough clinical evidence, the treatment and prognosis of idiopathic spinal cord herniation are still elusive. Herein, we reported a case of idiopathic spinal cord herniation occurring at the C7–T1 levels that was treated by surgical reduction.

Case description

A 44-year-old Chinese woman presented with a 5-year history of numbness and weakness in the bilateral lower limbs. Spinal magnetic resonance imaging demonstrated ventral displacement of the spinal cord at the C7–T1 levels, and there seemed to be a cuneiform space-occupying lesion dorsal to the spinal cord. A diagnosis of the spinal intradural extramedullary tumor was suspected. An exploratory operation was performed via a posterior midline approach. Intraoperatively, we found a defect in the ventral dura through which the spinal cord herniated to the epidural space. After the herniated parenchyma was returned, an artificial dura matter was used to repair the defect. The postoperative course was uneventful. After a 3-month follow-up, the lower-extremity weakness was significantly improved, and there was no recurrence of the spinal cord herniation.

Conclusion

Preoperative diagnosis of idiopathic spinal cord herniation is exceedingly challenging. Surgical reduction of the herniated spinal cord with the repair of the dural defect is an effective approach for the treatment of this rare disorder, and the surgical outcome is favorable.

A unique case of pure lateral spinal cord herniation

BACKGROUND

Spinal cord herniation (SCH) remains a challenging diagnosis for neuroradiologists and may require treatment challenging for neurosurgeons. Most cord herniations are usually found at anterior thoracic levels.

CLINICAL PRESENTATION

A 28-year-old woman presented at our department with a 7-year history of progressive myelopathy. MR analysis showed a displacement of the spinal cord in a lateral thoracic dural defect. The herniated cord was released using a microscope and the patient significantly recovered 6 months after surgery.

CONCLUSION

We present a unique case of pure lateral SCH. In the light of reviewed literature and operative findings, the underlying pathophysiological mechanisms are discussed.

Single-centre study comparing surgically and conservatively treated patients with spinal cord herniation and review of the literature

Introduction

Spinal cord herniation (SCH) is a rare cause of progressive myelopathy and Brown-Séquard-Syndrome.

Research question

Evaluation of functional outcome after SCH treatment compared to conservatively treated patients.

Material and methods

We retrospectively analysed functional outcome in SCH patients treated between 2009 and 2020. We conducted a systematic search using PubMed, MEDLINE and EMBASE to perform a pooled analysis in SCH patients.

Results

Our hospital cohort included 17 patients of which 9 were treated surgically. Mean age was 51.9 years, 58.8% of the patients were female. In 4/9 patients (44.4%) the neurological state remained stable after surgery. Four patients improved (44.4%) and one deteriorated after surgery (11.1%). Conservatively treated patients had a higher deterioration rate on follow-up with 3/8 patients deteriorating (37.5%). In our pooled analysis, 109/145 (75.2%) of patients improved, 32/145 (22.1%) remained stable and 4/145 patients deteriorated (2.8%). Among the available data of nine cohorts, mean recovery rate measured by the JOA score was 36.6% (SD 14.4). In our pooled multivariable model lower preoperative JOA score was associated with worse functional outcome (OR 0.86, 95%CI 0.74–0.99, p ​= ​.04).

Discussion and conclusion

Our data shows that patients who are treated surgically have a higher improvement rate and acceptable perioperative morbidity compared to conservatively treated patients. Lower preoperative JOA score decreases chances of improved functional outcome on follow-up. We therefore advocate early surgery for symptomatic patients. Wait and see appears outdated due to progressive impairment and decreased chances of recovery. However, it is still an option in asymptomatic incidental SCH patients.

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Evaluation of 17 patients with myelon herniation, 9 undergoing surgical treatment, 8 choosing conservative treatment.

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In the surgically treated group, 44.4% improved after surgery compared to none in the conservative group.

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11.1% deteriorated in the surgically treated compared to 37.5% in the conservatively treated group.

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Surgically treated patients have a higher improvement rate.

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Lower preoperative JOA score is associated with less improvement advocating early surgery in symptomatic patients.

Genetic analysis of spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord: a case series

Background

Spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord is better known as herniated spinal cord. There are many arguments in favour of considering it a developmental defect. From this point of view, it is a type of neural tube disorder. Neural tube disorders can be caused by multiple factors, including a genetic factor. A common genetic defect in patients with a spinal dysraphism with a hamartomatous growth of the spinal cord is sought for.

Case presentation

In two patients with a symptomatic lesion and referred to an academic hospital a genetic analysis was performed after informed consent. Whole-exome analysis was performed.

: Whole-exome analysis did not result in identification of a clinically relevant genetic variant.

Conclusions

This the first study to investigate the genetic contribution to spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord. We could not establish a genetic cause for this entity. This conclusion cannot be definitive due to the small sample size. However, the incidental occurrence, the lack of reports of inheritance of this disorder and the absence of contribution to syndromal disorders favours a defect of normal development of the spinal cord.

Nontraumatic Spinal Cord Compression: MRI Primer for Emergency Department Radiologists

The occurrence of acute myelopathy in a nontrauma setting constitutes a medical emergency for which spinal MRI is frequently ordered as the first step in the patient's workup. The emergency department radiologist should be familiar with the common differential diagnoses of acute myelopathy and be able to differentiate compressive from noncompressive causes. The degree of spinal cord compression and presence of an intramedullary T2-hyperintense signal suggestive of an acute cord edema are critical findings for subsequent urgent care such as surgical decompression. Importantly, a delay in diagnosis may lead to permanent disability. In the spinal canal, compressive myelopathy can be localized to the epidural, intradural extramedullary, or intramedullary anatomic spaces. Effacement of the epidural fat and the lesion's relation to the thecal sac help to distinguish an epidural lesion from an intradural lesion. Noncompressive myelopathy manifests as an intramedullary T2-hyperintense signal without an underlying mass and has a wide range of vascular, metabolic, inflammatory, infectious, and demyelinating causes with seemingly overlapping imaging appearances. The differential diagnosis can be refined by considering the location of the abnormal signal intensity within the cord, the longitudinal extent of the disease, and the clinical history and laboratory findings. Use of a compartmental spinal MRI approach in patients with suspected nontraumatic spinal cord injury helps to localize the abnormality to an epidural, intradural extramedullary, or intramedullary space, and when combined with clinical and laboratory findings, aids in refining the diagnosis and determining the appropriate surgical or nonsurgical management.Online supplemental material is available for this article.^©RSNA, 2019.

Idiopathic spinal cord herniation

Idiopathic spinal cord herniation is a rare but important and increasingly recognised cause of myelopathy seen in the thoracic spine. The factors that contribute to the aetiology of the condition and of the dural defect through which the cord herniates remain under debate. We discuss the clinical features and proposed pathophysiology of the condition, and illustrate key imaging findings on MRI, fluoroscopy and computed tomography (CT) myelography to establish the diagnosis, and discuss relevant differential diagnoses. Awareness and recognition of the condition is key as surgical intervention can improve outcomes for patients.

Thoracic idiopathic spinal cord herniation in a young patient: a diagnostic and therapeutic challenge

Idiopathic Spinal Cord Herniation (ISCH) is considered to be a rare cause of Thoracic Myelopathy. It is secondary to the gliding of the Spinal Cord through an anterior dural defect, without a completely defined cause. We present a case of ISCH which, even though was in its usual location, developed in a woman at a younger age than expected. The patient was 20 years old when diagnosed with Brown-Séquard Syndrome. MRI showed herniation at T4-T5 level, which was corrected using a posterior approach to expose the dural defect, reduce the herniation and place a heterologous graft. Postoperatively, neurological function improved, and adequate reduction was seen on imaging. Given the reports of recurrence and deterioration that have been seen after 18 months, follow-up was prolonged for a total of 2 years. We consider postoperative MRI performance important to establish the degree of reduction and alignment of the Spinal Cord.

Duplication of Ventral Dura as a Cause of Ventral Herniation of Spinal Cord-A Report of Two Cases and Review of the Literature

BACKGROUND

Idiopathic spinal cord herniation (ISCH) is a treatable spinal disease. It is rare and often misdiagnosed, causing a delay in management. The etiology is multifactorial, with one of the causes being duplication of the ventral dura. The spinal cord herniates within this defect and becomes strangulated, causing neurological deficits. We report the duplication of a ventral spinal cord as an important cause of ISCH in our review.

CASE DESCRIPTION

We present 2 cases of ISCH with duplication of the dura, including their relevant clinical and imaging features. The patients underwent surgical reduction of the herniated spinal cord with enlargement of the defect and placement of a dural substitute ventral to the cord. We have also reported the outcomes of the 2 patients, with an emphasis on the factors predictive of poor outcomes (i.e., long-standing symptoms, a delay in intervention, poor neurological status at presentation, and a thinned out atrophic spinal cord found during surgery). We also reviewed the available data for duplication of the dura with ISCH.

CONCLUSIONS

Very few asymptomatic patients can be treated conservatively. The surgical outcomes have been favorable for symptomatic patients. Proper exposure, gentle manipulation while reducing the herniated spinal cord, enlargement of the defect, and the use of intraoperative monitoring will help limit the postoperative deficits. Duplication of the ventral dura is an important cause of ISCH. It prevents the formation of an anterior pseudomeningocele after surgery. Owing to the rarity of the disease and the lack of follow-up data with recurrence rates, it has not been possible to form clear guidelines for management.

Double trouble!!! An unusual presentation of cervical cord herniation and medial end clavicle non-union in a single patient

Non-union of medial end clavicle is rare. Though traditionally they have been treated with conservative methods, surgery at initial presentation should be considered in these patients since conservative treatment can lead to non-union. Herniation of spinal cord, though rare, is seen in the thoracic region but can also occur in the cervical region post-traumatically as seen in our patient.

Pathogenesis of Idiopathic Ventral Herniation of Spinal Cord: Neuropathologic Analysis

BACKGROUND

Idiopathic ventral herniation of the spinal cord is rarely seen as a cause of gradually increasing neurologic deficit. Its cause has never been clarified. It could be the result of a developmental disorder at 30- to 60-day gestational age. Neuropathologic analysis of herniated spinal cord tissue could probably support this hypothesis.

CASE DESCRIPTION

In a patient suffering from idiopathic ventral herniation of the spinal cord, a biopsy was performed in order to reduce the space-occupying effect. The biopsy was taken while intraoperative neuromonitoring was used. The patient recovered uneventfully without any additional deficit. Tissue analysis included histopathologic, immunohistochemical, and molecular examination (methylation profiling). The tissue did not appear as a normally functioning spinal cord; instead, a non-neoplastic glio-(neuronal) proliferation was found.

CONCLUSION

These findings support a developmental disorder as a cause for idiopathic ventral spinal cord herniation.