Tethered thoracic cord resulting from spinal cord herniation

Duroplasty in iatrogenic dorsal spinal cord herniation: illustrative case

BACKGROUND

The case report detailed an unusual presentation of an iatrogenic dorsal cord herniation at the level of the thoracic cord after insertion of an epidural catheter 8 months before presentation to the neurosurgical clinic.

OBSERVATIONS

Only 13 cases of iatrogenic dorsal cord herniation, most of which occurred after spinal surgery, have been described in the literature. This was the first case of a spinal cord hernia described after the insertion of an epidural catheter. In this case study, the authors described a 38-year-old man who presented with progressive lower limb weakness, sensory deficits, perianal numbness, and urinary/fecal incontinence. He was diagnosed with a spinal cord hernia that reherniated after an initial sandwich duroplasty repair. Definitive repair was made after his re-presentation using an expansile duroplasty.

LESSONS

In patients with previous spinal instrumentation who present with neurological symptoms, spinal cord herniation should be considered a likely differential despite its rarity. In this case, a simple duroplasty was insufficient to provide full resolution of symptoms and was associated with recurrence. Perhaps a combination of graft and expansile duroplasty may be used for repair, especially when associated with a tethered cord and in the presence of significant adhesions.

Idiopathic herniation of the thoracic spinal cord

Since 1974, when Wortzman et al were the first to describe a case of idiopathic spinal cord herniation (ISCH), the number of reported cases has increased owing to magnetic resonance imaging (MRI) now is routinely available for patients with myelopathy and spinal surgeons are becoming more familiar with this clinical entity. This extremely rare herniation occurs exclusively in the thoracic spine, causing slowly progressive myelopathy. Diagnosis is based on ventral displacement of the spinal cord in the thoracic spine. MRI is the technique of choice to exclude a posterior arachnoid cyst, the most common mistaken diagnosis, and to recognize a spinal cord herniation when an anterior dural defect is present. A case of ISCH is reported and a Literature review of this clinical entity often mis-diagnosed has been obtained.

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.

Idiopathic Spinal Cord Herniation Associated With a Thoracic Disc Herniation: Case Report, Surgical Video, and Literature Review

PURPOSE

The aim of this publication is to present a case of idiopathic spinal cord herniation (ISCH) associated with a transdural disk herniation, demonstrate an operative technique used to treat this condition and provide an updated review the literature.

BACKGROUND CONTEXT

ISCH is an infrequent condition that can cause progressive myelopathy leading to severe neurological dysfunction. This condition is characterized by ventral displacement of the spinal cord across a defect in the dura, either congenital or acquired, resulting in vascular compromise and adhesion that subsequently causes injury to the spinal cord. We present the management of such a patient, in addition to a review of the literature regarding management of ISCH.

METHODS

This patient underwent surgery using the dural graft sling technique for repair of the dural defect and restoration of normal spinal cord position within the thecal sac. A review of the literature revealed a total of 171 patients supplemented by our 1 patient, which were then analyzed.

RESULTS

The majority of patients, treated with a variety of surgical techniques, experienced improvements in symptomatology. Our patient experienced significant improvement in symptomatology.

CONCLUSIONS

Although ISCH is a rare clinical condition that causes myelopathy, patients managed with surgery generally, though not universally, have a favorable neurological outcome. The associated surgical technique video demonstrates the dural sling technique for the treatment of this rare disorder.

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.

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.

Dorsal thoracic spinal cord herniation: report of an unusual case and review of the literature

BACKGROUND CONTEXT

Spinal cord herniation is a rare but well-documented condition that has been associated with tethering through the dural defect. Both spinal cord herniation and cord tethering result in progressive myelopathy that can be improved or stabilized with surgical intervention. Most cases of herniation are caused by dural defects in the ventral or ventrolateral thoracic spine, rarely occurring through the dorsal dura. This is the first reported case of a spontaneous dorsal herniation.

PURPOSE

To describe a unique case of thoracic tethered cord resulting from a dorsal dural defect through which there is spinal cord herniation.

STUDY DESIGN

A case report and review of the literature.

METHODS

A 55-year-old man presented with progressive low back pain, paresthesias, and weakness in his left lower extremity that was exacerbated by walking. Imaging revealed a dorsal dural defect with tethering and herniation of the spinal cord at T7.

RESULTS

The patient underwent a T6-T7 laminoplasty to release the tethered cord and repair the dural defect. At 1-year follow-up, the patient noted improvement in strength and back spasticity.

CONCLUSIONS

Spinal cord herniation through a dural defect is an uncommon but important cause of symptomatic tethered cord in adults. Surgical intervention can significantly alter the course and prevent further disability.

Idiopathic thoracic spinal cord herniation: retrospective analysis supporting a mechanism of diskogenic dural injury and subsequent tamponade

BACKGROUND AND PURPOSE

tSCH in the absence of spinal trauma or surgery is a rare disorder for which numerous mechanisms have been proposed. Here, we have conducted an analysis of images in all published reports of idiopathic tSCH and identified evidence supporting a pathogenesis in which anterior dural erosion at thoracic levels generates a CSF leak that pushes adjacent spinal tissue to tamponade the dural defect, causing progressive myelopathy. Additionally, we describe a case of tSCH in which postural headache was a significant symptom before myelopathy. This finding suggests that tSCH pathogenesis may be related to spontaneous intracranial hypotension.

MATERIALS AND METHODS

Published imaging from all available prior case reports in the scientific literature was reviewed to determine whether tSCH occurred at the disk or bone level. The presence of EDF, HNP, or an osteophyte in the spinal canal was determined from review of published images. Additionally, 3 previously unreported cases from the teaching files of our department were assessed by using these criteria.

RESULTS

In greater than two-thirds (47 of 67) of identified cases with published images, tSCH occurred at a disk level. When assessment was possible, EDF, HNP, and osteophytes were present in 26.8%, 30.7%, and 26.2% of cases, respectively. Overall, 52.3% of cases with published images demonstrated evidence of these abnormalities.

CONCLUSIONS

Our analysis of published imaging indicates that tSCH occurs preferentially at spinal levels and with imaging findings consistent with dural injury that support the proposed etiology of this disorder.

The value of intraoperative motor evoked potential monitoring during surgical intervention for thoracic idiopathic spinal cord herniation

OBJECT

Thoracic idiopathic spinal cord herniation (TISCH) is a rare neurological disorder characterized by an incarceration of the spinal cord at the site of a ventral dural defect. The disorder is associated with clinical signs of progressive thoracic myelopathy. Surgery can withhold the natural clinical course, but surgical repair of the dural defect bears a significant risk of additional postoperative motor deficits, including permanent paraplegia. Intraoperative online information about the functional integrity of the spinal cord and warning signs about acute functional impairment of motor pathways could contribute to a lower risk of permanent postoperative motor deficit. Motor evoked potential (MEP) monitoring can instantly and reliably detect dysfunction of motor pathways in the spinal cord. The authors have applied MEPs during intraoperative neurophysiological monitoring (IOM) for surgical repair of TISCH and have correlated the results of IOM with its influence on the surgical procedure and with the functional postoperative outcome.

METHODS

The authors retrospectively reviewed the intraoperative neurophysiological data and clinical records of 4 patients who underwent surgical treatment for TISCH in 3 institutions where IOM, including somatosensory evoked potentials and MEPs, is routinely used for spinal cord surgery. In all 4 patients the spinal cord was reduced from a posterior approach and the dural defect was repaired using a dural graft.

RESULTS

Motor evoked potential monitoring was feasible in all patients. Significant intraoperative changes of MEPs were observed in 2 patients. The changes were detected within seconds after manipulation of the spinal cord. Monitoring of MEPs led to immediate revision of the placement of the dural graft in one case and to temporary cessation of the release of the incarcerated spinal cord in the other. Changes occurred selectively in MEPs and were reversible. In both patients, transient changes in intraoperative MEPs correlated with a reversible postoperative motor deficit. Patients without significant changes in somatosensory evoked potentials and MEPs demonstrated no additional neurological deficit postoperatively and showed improvement of motor function during follow-up.

CONCLUSIONS

Surgical repair of the dural defect is effected by release and reduction of the spinal cord and insertion of dural substitute over the dural defect. Careful monitoring of the functional integrity of spinal cord long tracts during surgical manipulation of the cord can detect surgically induced impairment. The authors' documentation of acute loss of MEPs that correlated with reversible postoperative motor deficit substantiates the necessity of IOM including continuous monitoring of MEPs for the surgical treatment of TISCH.

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

BACKGROUND CONTEXT

Idiopathic spinal cord herniation (ISCH) is a rare cause of progressive myelopathy. Preoperative diagnosis can be made with magnetic resonance imaging (MRI). Many surgical techniques have been applied by various authors, and ISCH is usually reversible by surgical treatment.

PURPOSE

To present a case of ISCH in two separate zones at two thoracic levels. To our knowledge, this is the first such case to be published in English literature. We also discuss the clinical findings, surgical procedures, and surgical outcomes for other previously reported cases of ISCH in the literature.

STUDY DESIGN

Case report.

METHODS

A 52-year-old woman with bilateral lower extremity weakness underwent thoracic MRI, which revealed transdural spinal cord herniation at two separate zones, namely, the T4-T5 and T5-T6 intervertebral disc levels.

RESULTS

During surgery, the spinal cord was reduced, the two separate dural defects were connected, and the new single defect was restored then reinforced with a thin layer of fascial graft. The posterior dural defect was then closed with interrupted stitches. The patient's neurologic status was characterized by no changing of the preoperative motor status. Follow-up MRI scans showed that the cord was replaced in the dural sac and showed cord hyperintensity in the herniation levels. The patient could move with a cane at the sixth month postoperatively.

CONCLUSIONS

Idiopathic spinal cord herniation is a rare clinical condition that should be considered in the differential diagnosis of paraplegia. Although progression of neurologic deficits can be very slow, reduction of the spinal cord and repair of the defect are crucial to stop or reverse the deterioration. The outcome for patients who initially have Brown-Séquard syndrome is significantly better than for patients who presented with spastic paralysis. To our knowledge, this case study represents the first reported instance in which two separate anterior dural defects caused two levels of anterior spinal cord herniation.

Image classification of idiopathic spinal cord herniation based on symptom severity and surgical outcome: a multicenter study

Object

The purpose of this study was to provide the first evidence for image classification of idiopathic spinal cord herniation (ISCH) in a multicenter study.

Methods

Twelve patients who underwent surgery for ISCH were identified, and preoperative symptoms, severity of paralysis and myelopathy, disease duration, plain radiographs, MR imaging and CT myelography findings, surgical procedure, intraoperative findings, data from spinal cord monitoring, and postoperative recovery were investigated in these patients. Findings on sagittal MR imaging and CT myelography were classified into 3 types: a kink type (Type K), a discontinuous type (Type D), and a protrusion type (Type P). Using axial images, the location of the hiatus was classified as either central (Type C) or lateral (Type L), and the laterality of the herniated spinal cord was classified based on correspondence (same; Type S) or noncorrespondence (opposite; Type O) with the hiatus location. A bone defect at the ISCH site and the laterality of the defect were also noted.

Results

Patients with Type P herniation had a good postoperative recovery, and those with a Type C location had significant severe preoperative lower-extremity paralysis and a significantly poor postoperative recovery. Patients with a bone defect had a significantly severe preoperative myelopathy, but showed no difference in postoperative recovery.

Conclusions

The authors' results showed that a Type C classification and a bone defect have strong relationships with severity of symptoms and surgical outcome and are important imaging and clinical features for ISCH. These findings may allow surgeons to determine the severity of preoperative symptoms and the probable surgical outcome from imaging.

Operative treatment of anterior thoracic spinal cord herniation: three new cases and an individual patient data meta-analysis of 126 case reports

OBJECTIVE

Anterior thoracic spinal cord herniation is a rare cause of progressive myelopathy. Much has been speculated about the best operative treatment. However, no evidence in favor of any of the promoted techniques is available to date. Therefore, we decided to analyze treatment procedures and treatment outcomes of anterior thoracic spinal cord herniation to identify those factors that determine postoperative outcome.

METHODS

An individual patient data meta-analysis was conducted, focusing on age, gender, vertebral segment of herniation, preoperative neurological status, operative interval, operative findings, operative techniques, intraoperative neurophysiological monitoring, postoperative imaging, neurological outcome and follow-up. Three cases from our own institution were added to the material collected. Bivariate analysis tests and multivariate logistic regression tests were used so as to define which variables were associated with outcome after surgical treatment of anterior thoracic spinal cord herniation.

RESULTS

Brown-Séquard syndrome and release of the herniated spinal cord appeared to be strong independent factors, associated with favorable postoperative outcome. Widening of the dura defect is associated with the highest prevalence of postoperative motor function improvement when compared with the application of an anterior dura patch (P < 0.036).

CONCLUSION

Most patients with anterior thoracic spinal cord herniation require operative treatment because of progressive myelopathy. Patients with Brown-Séquard syndrome have a better prognosis with respect to postoperative motor function improvement. In this review, spinal cord release and subsequent widening of the dura defect were associated with the highest prevalence of motor function improvement. D-wave recording can be a very useful tool for the surgeon during operative treatment of this disorder.

Idiopathic spinal cord herniation: case report and review of the literature

BACKGROUND

Idiopathic spinal cord herniation (ISCH) is a rare cause of progressive myelopathy frequently present in Brown-Séquard syndrome. Preoperative diagnosis can be made with magnetic resonance imaging (MRI). Many surgical techniques have been applied by various authors and are usually reversible by surgical treatment.

METHODS

Case report and review of the literature.

FINDINGS

A 45-year-old woman with Brown-Séquard syndrome underwent thoracic MRI, which revealed transdural spinal cord herniation at T8 vertebral body level. During surgery the spinal cord was reduced and the ventral dural defect was restorated primarily and reinforced with a thin layer of subdermal fat. The dural defect was then closed with interrupted stitches.

RESULTS

Although neurologic status improved postoperatively, postsurgical MRI demonstrated swelling and abnormal T2-signal intensity in the reduced spinal cord. Review of the English language literature revealed 100 ISCH cases.

CONCLUSIONS

ISCH is a rare clinical entity that should be considered in differential diagnosis of Brown-Séquard syndrome, especially among women in their fifth decade of life. Outcome for patients who initially had Brown-Séquard syndrome was significantly better than for patients who presented with spastic paralysis. Although progression of neurologic deficits can be very slow, reduction of the spinal cord and repair of the defect are crucial in stopping or reversing the deterioration.

Tethered cord syndrome: an updated review

Tethered cord syndrome (TCS) is a diverse clinical entity characterized by symptoms and signs which are caused by excessive tension on the spinal cord. The majority of cases are related to spinal dysraphism. TCS can present in any age group, and presentations differ according to the underlying pathologic condition and age, with pain, cutaneous signs, orthopedic deformities and neurological deficits being the most common. Surgical untethering is indicated in patients with progressive or new onset symptomatology attributable to TCS. The surgical strategy aims to release the tethering structure and thus the chronic tension on the cord. Early operative intervention is associated with improved outcomes. Pain relief is accomplished in almost all cases. Realistic surgical goals include relief of pain and stabilization of neurological function, although improvement in function is often seen. Cord untethering can also halt the progression of scoliosis. The benefits of surgery are debated in asymptomatic patients and patients with normal imaging.

Diagnosis and treatment of spinal cord herniation: a combined experience

OBJECT

Idiopathic spinal cord herniation (ISCH) is an uncommon clinical entity typically presenting with lower-extremity myelopathy. Despite the existence of 85 ISCH cases in the literature, misdiagnosis and delayed diagnosis remain a major concern.

METHODS

The authors conducted a retrospective review of patients who underwent surgery for ISCH at their institutions between 1993 and 2004. Seven patients were treated for ISCH, five in New York and two in Buenos Aires. The patients' ages ranged from 32 to 72 years. There were three men and four women. The interval between the onset of symptoms and surgery ranged from 12 to 84 months (mean 42.1 months). Preoperatively, spinal cord function in four patients was categorized as American Spinal Injury Association (ASIA) Grade D, and that in the other three patients was ASIA Grade C. In all patients a diagnosis of posterior intradural arachnoid cyst had been rendered at other institutions, and three had undergone surgery for the treatment of this entity. In all cases, the herniation was reduced and the defect repaired with a dural patch. The follow-up period ranged from 10 to 147 months (mean 49.2 months). Clinical recovery following surgery varied; however, there was no functional deterioration compared with baseline status. Syringomyelia, accompanied by neurological deterioration, developed post-operatively in two patients at 2 and 10 years, respectively.

CONCLUSIONS

Patients presenting with a diagnosis of posterior intradural arachnoid cyst should be evaluated carefully for the presence of an anterior spinal cord herniation. Based on the authors' literature review and their own experience, they recommend offering surgery to patients even when neurological compromise is advanced.

Idiopathic spinal cord herniation causing progressive Brown-Séquard syndrome

We report a 59-year-old woman with a 2.5 year history of progressive loss of temperature sensation and dysesthesia in the right and weakness in the contralateral lower limb. Magnetic resonance imaging (MRI) and computed tomography myelography of the spinal cord demonstrated transdural herniation and deformation of the spinal cord in the upper thoracic spine. The herniated part of the spinal cord was untethered and replaced, and the anterior dural defect was closed. At a clinical follow-up 3 months later, the motor and sensory functions were almost restored. MRI at this time showed disentanglement of spinal cord adherence.

Idiopathic spinal cord herniation: diagnostic, surgical, and follow-up data obtained in five cases

✓ Idiopathic spinal cord herniation (ISCH) is a rare, although increasingly recognized, cause of myelopathy. It is the result of an anterior dural defect in the thoracic spine through which the spinal cord herniates. Surgical restoration of the herniated cord to its normal position is usually followed by significant improvement in patients' clinical status. Differing surgical techniques have been used to manage the dural defect.

In this report the authors discuss the cases of five patients (four women and one man) with ISCH treated during a 13-year period. Clinical and imaging findings in each patient are reported. Two different surgical techniques were used to treat this condition: dural defect enlargement in two cases and dural patch secured with stitches in three. The intra-and postoperative findings are discussed in relation to the two surgical techniques.

Based on the results and complications in these five cases, the authors now believe that ISCH should be treated, when feasible, by using a dural patch to close the dural defect at the site of the herniation.

Transdural spinal cord herniation: pre- and postoperative MRI findings

Idiopathic transdural spinal cord herniation (ICSH), a rare condition which may cause progressive myelopathy, can be diagnosed preoperatively by MRI. Surgical treatment usually results in the resolution of symptoms and, thus, familiarity with the imaging findings in this condition impacts patient management. We present the case of a 36-year-old woman in whom the initial MRI findings were thought to be consistent with only an arachnoid cyst compressing the spinal cord. After surgery, her symptoms remained unchanged, and a repeat MRI study was interpreted as being compatible with a transdural spinal cord herniation. Repeated surgery with reduction of the herniation resulted in significant clinical improvement.

Spontaneous Thoracic Spinal Cord Herniation: Three Cases with Long-term Follow-up

OBJECTIVE AND IMPORTANCE

Spontaneous thoracic spinal cord herniation (STSCH) is an uncommon cause of thoracic myelopathy. Fewer than 40 cases have been reported in the English language literature with a mean follow-up of less than 6 months.

CLINICAL PRESENTATION

We have encountered three patients diagnosed with STSCH in the last 6 years at our institution. These patients presented with symptoms and signs localizing to the thoracic spinal cord. Magnetic resonance imaging revealed ventral thoracic spinal cord displacement in each.

INTERVENTION

One patient was treated surgically, two managed expectantly. Two patients have been followed for greater than 5 years, whereas a third has been followed for 15 months.

CONCLUSION

Our experience suggests that patients with neurological symptoms and signs attributable to STSCH may not progress and therefore may be followed with clinical and magnetic resonance imaging surveillance. When surgery is indicated for progressive STSCH, late retethering may occur.

Transdural herniation of the thoracic spinal cord: untethering via a posterolateral transpedicular approach. Report of three cases

Anterior spinal cord herniation is a well-documented condition in which the thoracic cord becomes tethered within a defect in the anterior dura mater. Typical procedures have involved a posterior approach with direct manipulation of the thoracic cord to expose and blindly release its point of tethering. The authors report three cases in which a novel approach for the treatment of anterior thoracic cord herniation was performed, cord manipulation and traction are minimized, and direct dural repair of the defect is performed.

Case of idiopathic thoracic spinal cord herniation with a chronic history: a case report and review of the literature

Idiopathic spinal cord herniation is a rare disease that presents with slowly progressive myelopathy. This article describes the clinical findings of a patient with a chronic history. A 68-year-old woman initially presented at the age of 32 years with left leg weakness. After slowly progressive neurological deterioration over 34 years, she became completely paraplegic. At the age of 66 years, magnetic resonance imaging resulted in a diagnosis of idiopathic spinal cord herniation at the T6/7 level. Surgery was performed to reduce aching of the lower extremities. The spinal cord was released from the dural defect through a T5-T8 laminectomy. The dural defect was enlarged by resecting its periphery to prevent reherniation of the spinal cord. After the surgery, pain in the lower extremities resolved and her motor function slightly improved. Although operative treatment is naturally recommended at the early stage of this disease, our case suggests that some symptoms can be resolved by surgical treatment despite prolonged, severe preoperative symptoms.

Upper thoracic spinal cord herniation after traumatic nerve root avulsion

✓ Transdural herniation of the spinal cord, a rare but well-documented entity, has been reported sporadically for more than 25 years as a possible cause for various neurological signs and symptoms ranging from isolated sensory or motor findings to myelopathy and Brown–Séquard syndrome. The authors report, to the best of their knowledge, the first case of upper thoracic spinal cord herniation occurring after traumatic nerve root avulsion.

Upper thoracic spinal cord herniation after traumatic nerve root avulsion

✓ Transdural herniation of the spinal cord, a rare but well-documented entity, has been reported sporadically for more than 25 years as a possible cause for various neurological signs and symptoms ranging from isolated sensory or motor findings to myelopathy and Brown—Séquard syndrome. The authors report, to the best of their knowledge, the first case of upper thoracic spinal cord herniation occurring after traumatic nerve root avulsion.

Idiopathic spinal cord herniation associated with a large erosive bone defect: a case report and review of the literature

We report a case of idiopathic spinal cord herniation associated with a large bone defect. MRI and computed tomographic myelography revealed ventral deviation of the spinal cord and erosion of the vertebral body at T6-T7. Microscopic surgery revealed a dural defect. The etiology of this condition has not been clarified. In most previously reported cases, the peak portion of the herniation was around the intervertebral disc space. In addition, in our patient, it was hard to think that the intervertebral disc has become depressed due to the pressure exerted by the spinal cord. We considered that a certain condition of the intervertebral disc, such as herniation, was one of the causes of the dural defect, and cerebrospinal fluid pulsation pushed the spinal cord toward that portion, causing herniation.

Idiopathic spinal cord herniation in the thoracic spine as a cause of intractable leg pain: case report and review of the literature

We recently experienced a case of idiopathic spinal cord herniation in the upper thoracic spine with development of severe unilateral leg pain: a 57-year-old man who had suffered from severe leg pain for about 15 years with lack of abnormality in his lumbar spine. On MRI of the thoracic spine, however, the spinal cord at T2-T3 was bent forward with dilatation of the posterior subarachnoid space. In combination with the findings of computed tomographic myelography, we diagnosed idiopathic spinal cord herniation and performed a surgical treatment. Immediately after the operation, his leg pain disappeared. Therefore, we concluded that the cause of his leg pain was herniation of the thoracic spinal cord.

Thoracic idiopathic spinal cord herniation at the vertebral body level: a subgroup with a poor prognosis? Case reports and review of the literature

The authors present two cases of thoracic idiopathic spinal cord herniation (TISCH) occurring at the vertebral body (VB) level in whom adequate surgical reduction failed to reverse symptoms. In the second case, in which TISCH occurred into a VB cavity, presentation was atypical (subacute spinal cord syndrome) and there was persistent postoperative deterioration. In both cases, adequate surgical reduction was achieved via a posterior midthoracic laminectomy, and reduction was maintained by closure of the anterior dural defect by using prosthetic material. Thoracic idiopathic spinal cord herniation occurring at a VB level may be technically well treated by surgical reduction, but the outcome appears less predictable. Herniation that occurs directly into a VB cavity may form a distinct subgroup in which the presentation is atypical and the prognosis worse.

Idiopathic spinal cord herniation: report of eight cases and review of the literature

STUDY DESIGN

A case series of eight patients with idiopathic spinal cord herniation and a review of the literature.

OBJECTIVE

To report on this rare entity, provide insight on its natural history, and propose an optimal management strategy.

SUMMARY OF BACKGROUND DATA

Idiopathic spinal cord herniation is a rare disease with 50 cases reported before the current study.

METHODS

Eight cases (follow-up 1 month to 8 years) are reported using available information from patient charts, interviews, and assessments. All imaging studies are reviewed. The review of the literature was performed using PUBMED.

RESULTS

Four patients, followed without surgical intervention, have not progressed. Of the three patients who underwent surgical repair by one of the authors, two improved and one was unchanged. A fourth patient, who was initially treated by another surgeon who failed to identify the dural defect and herniation, had a poor outcome.

CONCLUSION

The pathophysiology of the dural defect is still uncertain. The typical presentation is Brown-Séquard syndrome. Microsurgical repair in cases with progression of neurologic deficits is usually successful in achieving recovery of function or arrest of progression.

Idiopathic spinal cord herniation associated with intervertebral disc extrusion: a case report and review of the literature

STUDY DESIGN

A case of idiopathic spinal cord herniation is reported, and the literature is reviewed.

OBJECTIVE

To report a case of thoracic spinal cord herniation with a ventral dural defect, probably caused by thoracic disc extrusion.

SUMMARY OF BACKGROUND DATA

Recently, reports of spinal cord herniation have been increasing. This increase can be attributed to the development of magnetic resonance imaging and increased awareness of this entity. However, the cause of the ventral dural defect remains unknown.

METHODS

A 54-year-old woman had experienced Brown-Séquard syndrome for 2 years. Magnetic resonance imaging demonstrated an S-shaped anterior kinking of the spinal cord, with dilation of the dorsal subarachnoid space.

RESULTS

After incision of the dural sac and gentle retraction of the spinal cord, a dural defect was recognized into which the spinal cord had herniated. An extruded disc was visualized through the defect at T3-T4. The ventral dural defect and the dorsal incision of the dural sac were repaired with a fascial graft from the thigh.

CONCLUSIONS

Intraoperative findings suggest that the thoracic disc herniation in the current case was the probable cause of the ventral dural defect. Surgical reconstruction using double fascial graft under careful spinal cord monitoring resulted in a satisfactory neurologic recovery.

Spinal cord herniation into an extradural arachnoid cyst

A herniation of the thoracic spinal cord into the mouth of an extradural arachnoid cyst is reported in a 37 year old man. This is the 20th case, but the first posterior herniation; all the others were anterior. He presented with progressive paraparesis and the magnetic resonance imaging (MRI) showed kinking of the cord into the cyst. Surgical release of the neck of the hernia was successful.

Spinal cord herniation into an extensive extradural meningeal cyst: postoperative analysis of intracystic flow by phase-contrast cine MRI

We report a patient with idiopathic spinal cord herniation who underwent postoperative myelography and phase-contrast cine magnetic resonance imaging (MRI) to clarify the condition of the ventral cystic lesion into which the spinal cord had been herniated. This 58-year-old man showed symptoms and signs compatible with Brown-Séquard syndrome. A myelogram and MRI showed that the spinal cord was incarcerated in a small space, and this finding led to the diagnosis of spinal cord herniation. In the operation, the herniated spinal cord was returned to the initial intradural space, and the dural defect was enlarged to prevent recurrence of the herniation. After the operation, leg muscle strength improved and bladder and bowel dysfunction resolved, but analgesia was unchanged. Postoperative myelography revealed a very large extradural cystic lesion, which extended from C2 to L1 vertebral level. A cerebrospinal fluid (CSF) flow study of the intradural space disclosed a near-normal pattern, but the intracystic CSF dynamics were abnormal. In the intracystic space at just the upper level of the lesion, cranial flow (reverse directional flow in comparison with the intradural flow) was seen in the systolic cycle after momentary fast caudal flow, and these CSF dynamics may have been related to the spinal cord herniation.

Spontaneous spinal cord herniation: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Spontaneous herniation of the spinal cord substance through a previously uninjured and/or untouched dura is a very exceptional occurrence. Spontaneous spinal cord herniation, which was first reported 25 years ago, is a cause of myelopathy that is treatable but difficult to diagnose.

CLINICAL PRESENTATION

A 49-year-old female patient who presented with a 3-year history of a burning sensation and hyperesthesia in her right leg and a 3-month history of left leg stiffness was diagnosed as exhibiting signs of Brown-Séquard syndrome. Magnetic resonance imaging of the thoracic spinal canal demonstrated S-shaped anterior kinking and transdural herniation of the spinal cord at the T3-T4 levels.

INTERVENTION

The patient underwent surgery via a three-level laminectomy. The herniated part of the spinal cord was microsurgically reduced, and the dural defect was repaired with Gore-Tex membrane (WL Gore & Associates, Flagstaff, AZ). The outcome of surgery was excellent.

CONCLUSION

Review of the world literature revealed 29 reported cases, with 27 of these cases being published since 1990. The clinical features, radiological diagnosis, and treatment options for this unique entity are summarized, with a synopsis of numerous misconceptions that appeared in the literature. With more familiarity with and increased awareness of this entity, more cases will be diagnosed.

Idiopathic spinal cord herniation: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Idiopathic spinal cord herniation (ISCH) is a rare condition, reported in only 25 patients thus far, in which the thoracic cord is prolapsed through an anterior dural defect. It typically presents in middle age as either Brown-Sequard syndrome or spastic paraparesis.

CLINICAL PRESENTATION

A 55-year-old woman initially presented at the age of 41 years with Brown-Sequard syndrome at the T8 disc space level on the left side. Investigations, including primitive magnetic resonance imaging, were deemed negative at that time. After a stepwise deterioration over 14 years, she presented again with spastic paraparesis and double incontinence, in addition to her previous spinothalamic dysfunction. Magnetic resonance imaging at this stage suggested either ISCH or a dorsal arachnoid cyst.

INTERVENTION

Through a T7-T8 laminectomy, a left-of-midline ISCH was identified and easily reduced by gentle cord traction. No dorsal arachnoid cyst was identified. The anterior dural defect was repaired with a XenoDerm patch (LifeCell Corp., Woodlands, TX). After surgery, there was improved motor and sphincter function. However, there was continued sensory disturbance.

CONCLUSION

ISCH is rare cause of thoracic cord dysfunction. Despite prolonged diagnostic delay, significant clinical improvement may be obtained with ISCH reduction and anterior dural repair.

[Paraplegia as initial manifestation of tethered spinal cord. Case report]

Tethered spinal cord (TSC) is a rare disorder; it occurs when the conus medularis is anchored to the base of the vertebral canal by thickened filum terminale cysts, lipoma and spinal dysraphia. This disorder may cause paraplegia, sensory and sphincter disturbance. We report a twenty-two months-old girl presenting with paraplegia. TSC diagnostic was confirmed by myelotomography. The patient was submitted to surgical relief of tethered filum terminale.