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

De Novo Formation of Idiopathic Spinal Cord Herniation

We investigated whether idiopathic spinal cord herniation is a congenital or acquired condition and undertook a study to determine the risk of developing iSCH in patients with persistent ventral spinal CSF leaks. De novo formation of iSCH was established among all 6 patients with iSCH who had undergone prior spinal imaging for symptoms unrelated to iSCH. Among 51 patients with persistent ventral spinal CSF leaks, iSCH developed in 2 patients (probability increased from 0% at 5 years to 9.4% at 10 years). This study shows that iSCH is an acquired condition, and early treatment of ventral CSF leaks offers a unique opportunity to prevent neurologic disability.

Duropathy as a rare motor neuron disease mimic: from bibrachial amyotrophy to infratentorial superficial siderosis

BACKGROUND

Bibrachial amyotrophy associated with an extradural CSF collection and infratentorial superficial siderosis (SS) are rare conditions that may occasionally mimic ALS. Both disorders are assumed to be due to dural tears.

CASE PRESENTATION

A 53-year-old man presented with a 7-year history of slowly progressive asymmetric bibrachial amyotrophy. Initially, a diagnosis of atypical motor neuron disease (MND) was made. At re-evaluation 11 years later, upper limb wasting and weakness had further progressed and were accompanied by sensorineural hearing loss. MRI of the brain and spine demonstrated extensive supra- and infratentorial SS (including the surface of the whole spinal cord) as well as a ventral longitudinal intraspinal fluid collection (VLISFC) extending along almost the entire thoracic spine. Osteodegenerative changes were observed at C5-C7 level, with osteophytes protruding posteriorly. The bony spurs at C6-C7 level were hypothesized to have lesioned the dura, causing a CSF leak and thus a VLISFC. Review of the MRI acquired at first evaluation showed that the VLISFC was already present at that time (actually beginning at C7 level), whereas the SS was not. 19 years after the onset of upper limb weakness, the patient additionally developed parkinsonism. Response to levodopa, brain scintigraphy with 123I-ioflupane and brain MRI with nigrosome 1 evaluation were consistent with idiopathic Parkinson's disease (PD). On the latest follow-up 21 years after symptom onset, the VLISFC was unchanged, as were upper arm weakness and wasting.

CONCLUSIONS

Based on the long-term follow-up, we could establish that, while the evidence of the VLISFC was concomitant with the clinical presentation of upper limb amyotrophy and weakness, the radiological signs of SS appeared later. This suggests that SS was not per se the cause of the ALS-like clinical picture, but rather a long-term sequela of a dural leak. The latter was instead the causative lesion, giving rise to a VLISFC which compressed the cervical motor roots. Dural tears can actually cause several symptoms, and further studies are needed to elucidate the pathophysiological correlates of "duropathies". Finally, as iron metabolism has been implicated in PD, the co-occurrence of PD with SS deserves further investigation.

Innovations in the Treatment of Spinal Cerebrospinal Fluid Leaks

Spontaneous spinal cerebrospinal fluid (CSF) leaks are uncommon but can be neurologically debilitating. When initial treatments fail, definitive repair or closure of the leak is indicated. Depending upon the type of leak present, innovative strategies for their treatment have been developed. Among them are open surgical techniques using a transdural approach for the closure of ventral CSF leaks, minimally invasive tubular techniques for the reduction and repair of lateral meningeal diverticula, and endovascular embolization of CSF-venous fistulas. Illustrative cases demonstrating the indications for and implementation of these techniques are provided.

Cranial and Spinal Cerebrospinal Fluid Leaks: Foundations of Identification and Management

Cerebrospinal fluid (CSF) leaks may occur at the skull base or along the spinal column and can cause a variety of debilitating neurological symptoms for patients. Recognizing the potential presence of a CSF leak and then identifying its source are necessary for accurate diagnosis and definitive treatment. A standardized workflow can be followed for successful leak localization, which often requires several diagnostic studies, and for definitive leak treatment, which can range from minimally invasive, needle-based approaches to a variety of surgical corrections. This review paper provides an overview of epidemiology, pathophysiology, and diagnostic workup for CSF leaks and introduces available treatment options. An illustrative case of a skull base CSF leak demonstrating diagnosis and surgical correction is provided.

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.

A case of conservatively managed idiopathic spinal cord herniation presenting with low-pressure headache

Idiopathic spinal cord herniation presenting with low-pressure headache is extremely rare. We present a case of thoracic ventral spinal cord herniation in a 35-year-old lady who presented with low-pressure headaches. To our knowledge, this is only the fourth case described in the literature of spontaneous ventral cord herniation presenting in this way. The patient was managed conservatively with no manifestation of focal neurological symptoms at 12-month follow-up. The proposed aetiology of spontaneous ventral cord herniation is an initial CSF leak via a dural defect, through which the cord subsequently also enters blocking the CSF leak. We endorse a conservative approach for patients who present similarly, secondary to the above pathophysiology.

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.

Full Endoscopic Repair of Spontaneous Ventral Cerebrospinal Fluid Leaks in the Spine: Systematic Review of Surgical Treatment Options and Illustrative Case

BACKGROUND

Spontaneous spinal cerebrospinal fluid (CSF) leaks are a rare entity that can lead to intracranial hypotension and associated headaches, meningismus, and patient debility. Surgical treatment may be necessary for patients who do not respond to conservative management. Surgical repair of CSF leaks located in the ventral thoracic spine traditionally require an invasive, open approach.

METHODS

We describe the case of a patient with a ventral thoracic spontaneous spinal CSF leak associated with a ventral bony osteophyte successfully treated with spinal endoscopy. We also provide a systematic review of the literature to better understand outcomes of this approach.

RESULTS

A total of 55 patients were included in the systematic review. The study designs found in the literature review included case reports (66.7%), retrospective cohorts (22.2%), and prospective cohorts (11.1%). Of the studies reporting data, 50% of studies stated they used an open posterior approach to the dural defect, while 37.5% reported using an open anterior approach to the pathology. Only 1 (12.5%) study reported using an endoscope. Most studies (62.5%) used primary closure of the dura in their technique, while 37.5% reported using a local tissue graft (fat or muscle) or a dural sealant for their closure technique, and 25% of studies reported using a dural substitute for their closure technique. Overall mean clinical follow-up was 19.8 months.

CONCLUSIONS

The endoscopic approach described here for treatment of this rare entity allows for removal of bony spicules/osteophytes and dural repair without the morbidity associated with traditional open dorsolateral or ventrolateral approaches.

Long-term Risks of Persistent Ventral Spinal CSF Leaks in SIH: Superficial Siderosis and Bibrachial Amyotrophy

BACKGROUND AND OBJECTIVES

Superficial siderosis, bibrachial amyotrophy, and spinal cord herniation are unusual but serious long-term sequelae of persistent spontaneous spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH), particularly ventral spinal CSF leaks. However, the risk of developing such sequelae has not been established in this population. We undertook this study to determine the risk of these serious complications of persistent ventral spinal CSF leaks.

METHODS

This cohort study was conducted using data from a prospectively maintained database of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. The patient population consisted of a consecutive group of patients with SIH and persistent ventral spinal CSF leaks who were first seen within 1 year of onset of SIH symptoms and who had at least 1 year of follow-up.

RESULTS

Among 51 patients with SIH and a persistent ventral spinal CSF leak, superficial siderosis developed in 6 patients and bibrachial amyotrophy in 2 patients during 280 patient-years of follow-up. The probability of these complications increased from 0% at 48 months to 4.5% (95% confidence interval [CI] 1.0%-28.0%) at 56 months, 10.5% (95% CI 3.0%-36.4%) at 96 months, 32.7% (95% CI 15.0%-62.8%) at 144 months, and 57.9% (95% CI 30.2%-87.6%) at 192 months. None of the patients developed spinal cord herniation.

DISCUSSION

Among patients with SIH and a persistent ventral spinal CSF leak, the risk of developing serious long-term sequelae is considerable. This study shows that early treatment of a ventral spinal CSF leak offers a unique opportunity to prevent neurologic disability from superficial siderosis and bibrachial amyotrophy.

Diskogenic Dural Defect Is the Reason for the Ventral Location of the Epidural Spinal Fluid Collection Seen in Superficial Siderosis

Purpose of Review

Superficial siderosis (SS) of the nervous system is often due to a dural pathology. This review focuses on recent developments related to the management of this subgroup of patients with SS.

Recent Findings

The presence of an epidural ventral spinal fluid collection in patients with SS is a clue to the presence of a diskogenic dural defect. The location of the defect is ascertained by a dynamic CT myelogram, which involves placing the patient in a prone position with hips elevated. This permits gravity-assisted preferential ventral localization of the contrast and active scanning during contrast injection facilitates a precise delineation of the initial point of contrast extravasation which localizes the defect.

Summary

Diskogenic dural defects are commonly the underlying etiology for SS in patients with a ventral spinal fluid collection. A dynamic CT myelogram facilitates detection and subsequent repair of these defects, which arrests the continued low-grade subarachnoid bleeding.

Neuroimaging of Spinal Cord and Cauda Equina Disorders

PURPOSE OF REVIEW

This article reviews the neuroimaging of disorders of the spinal cord and cauda equina, with a focus on MRI. An anatomic approach is used; diseases of the extradural, intradural-extramedullary, and intramedullary (parenchymal) compartments are considered, and both neoplastic and non-neoplastic conditions are covered. Differentiating imaging features are highlighted.

RECENT FINDINGS

Although T2-hyperintense signal abnormality of the spinal cord can have myriad etiologies, neuroimaging can provide specific diagnoses or considerably narrow the differential diagnosis in many cases. Intradural-extramedullary lesions compressing the spinal cord have a limited differential diagnosis and are usually benign; meningiomas and schwannomas are most common. Extradural lesions can often be specifically diagnosed. Disk herniations are the most commonly encountered mass of the epidural space. Cervical spondylotic myelopathy can cause a characteristic pattern of enhancement, which may be mistaken for an intrinsic myelopathy. A do-not-miss diagnosis of the extradural compartment is idiopathic spinal cord herniation, the appearance of which can overlap with arachnoid cysts and webs. Regarding intrinsic causes of myelopathy, the lesions of multiple sclerosis are characteristically short segment but can be confluent when multiple. Postcontrast MRI can be particularly helpful, including when attempting to differentiate the long-segment myelopathy of neurosarcoidosis and aquaporin-4 (AQP4)-IgG-seropositive neuromyelitis optica spectrum disorder (NMOSD) and when characterizing spinal cord tumors such as primary neoplasms and metastases. Spinal dural arteriovenous fistula is another do-not-miss diagnosis, with characteristic MRI features both precontrast and postcontrast. Tract-specific white matter involvement can be a clue for diseases such as subacute combined degeneration, paraneoplastic myelopathy, and radiation myelitis, whereas gray matter-specific involvement can suggest conditions such as cord infarct, viral myelitis, or myelin oligodendrocyte glycoprotein (MOG)-IgG associated disorder.

SUMMARY

Knowledge of the neuroimaging findings of the many causes of spinal cord and cauda equina dysfunction is critical for both neurologists and neuroradiologists. A structured approach to lesion compartmental location and imaging feature characterization is recommended.

Spinal cord herniation following multilevel anterior cervical discectomy and fusion: A case report and literature review

Background:

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spinal operations. Spinal cord herniation following these procedures is rare, more typically being described as occurring posteriorly rather than following anterior corpectomy and fusion (e.g., reported in four corpectomy cases). Here, we describe a case in which spinal cord herniation was attributed to a three-level ACDF.

Case Description:

A 31-year-old male initially presented with a 1 year’s duration of increasing myelopathy attributed to MR documented three-level disc disease (C4-C7). He successfully underwent a three-level ACDF without complications/durotomy. One year later, he again presented, with myelopathy (i.e., recurrent neck pain and stiffness) newly attributed to MR documented anterolateral C4-C5 cord herniation. As he declined further surgery, he was treated medically (e.g., utilizing analgesia and physiotherapy) and was no worse 6 months later.

Conclusion:

The occurrence of spinal cord herniation through a prior ACDF defect must be considered when patients present with recurrent myelopathy following previous ACDF surgery.

Long-term course of anterior spinal cord herniation presenting with an upper motor neuron syndrome: case report illustrating diagnostic and therapeutic implications

BACKGROUND

Anterior spinal cord herniation (aSCH) is a rare cause of myelopathy which may present as pure motor syndrome and mimic other degenerative diseases of the spinal cord. In slowly progressive cases, diagnosis may be impeded by equivocal imaging results and mistaken for evolving upper motor neuron disease. As early imaging studies are lacking, we aimed to provide a detailed description of imaging and neurophysiology findings in a patient with aSCH, focusing on the early symptomatic stages.

CASE PRESENTATION

We here present the case of a 51-year old male patient with an episode of pain in the right trunk and a normal spinal MRI. After a symptom-free interval of 8 years, spasticity and paresis evolved in the right leg. There was subtle ventral displacement and posterior indentation of the thoracic spinal cord on MRI which, in retrospect, was missed as an early sign of aSCH. After another 3 years, symptoms spread to the left leg and a sensory deficit of the trunk became evident. Follow-up MRI now clearly showed an aSCH. Neurosurgical intervention consisted of remobilization of the herniated spinal cord and patch closure of the dura defect. Over the following years, motor and sensory symptoms partially improved.

CONCLUSIONS

The history of this patient with aSCH illustrates the importance of careful longitudinal clinical follow-up with repeated imaging studies in progressive upper motor neuron syndromes. Specific attention should be paid to a history of truncal pain and to MRI findings of a ventrally displaced spinal cord. Neurosurgical intervention may halt the progression of herniation.

Role of Conventional Dynamic Myelography for Detection of High-Flow Cerebrospinal Fluid Leaks

Background

Spinal imaging is essential to identify and localize cerebrospinal fluid (CSF) leaks in spontaneous intracranial hypotension (SIH) patients when targeted treatment is necessary.

Purpose

Provide an in-depth presentation of the conventional dynamic myelography (CDM) technique for localizing spinal CSF leaks in SIH patients.

Material and Methods

Consecutive SIH patients with a CSF leak confirmed on CDM and postmyelography computed tomography (CT) investigated at our institution between 2013 and 2019 were retrospectively analyzed. Intraoperative reports were reviewed to confirm the accuracy of CDM.

Results

In total, 62 patients (mean age 45 years) were included; 48 with a ventral dural tear, 12 with a meningeal diverticulum, and in 2 patients positive for spinal longitudinal extradural CSF collection the site remained unclear. The leak was identified during the first and the second CDM in 43 and 17 patients, respectively. The use of CDM correctly identified the site of the CSF leak in all but one patient undergoing surgical closure (45/46, 98%). The mean fluoroscopy time was 7.8 min (range 1.8–14.4 min) with a radiation dose for a single examination of 310 mGy (range 28–1237 mGy).

Conclusion

The CDM procedure has a high accuracy for spinal CSF leak localization including dural tears and spinal nerve diverticula. It is the technique with the highest temporal resolution, is robust to breathing artifacts, allows great flexibility regarding patient positioning, compares favorably to other dynamic examinations with respect to the radiation dose and does not require general anesthesia. For CSF venous fistulas, however, other dynamic examinations, such as digital subtraction myelography, seem more appropriate.

Video online

The online version of this article contains 4 videos. The article and the videos are online available (10.1007/s00062-020-00943-w). The videos can be found in the article back matter as “Electronic Supplementary Material”.

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.

Traumatic Ventral Cervical Spinal Cord Herniation: A Case Report

Spinal cord herniation (SCH) is an uncommon traumatic event that should be considered in patients with vertebral fractures who develop an unusual constellation of autonomic and motor deficits. Herein, we describe a case of rapidly deteriorating neurological function following cervical spine fracture including sequelae such as bilateral lower-extremity weakness, loss of upper extremity motor function, and priapism. Decompression of the spinal cord allowed for the identification of the unusual herniation of the spinal cord and prevention of any further worsening of the neurological injury. Hyperflexion of the cervical spine upon traumatic impact provided the impetus for vertebral retropulsion and subsequent incarceration of the spinal cord. This phenomenon should be considered in the setting of acute traumatic injury to the cervical spinal cord. Surgical intervention is likely to allow the preservation of the remaining neurological function.

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.

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.

Differentiation of idiopathic spinal cord herniation from dorsal arachnoid webs on MRI and CT myelography

OBJECTIVE

Dorsal arachnoid webs (DAWs) and spinal cord herniation (SCH) are uncommon abnormalities affecting the thoracic spinal cord that can result in syringomyelia and significant neurological morbidity if left untreated. Differentiating these 2 entities on the basis of clinical presentation and radiological findings remains challenging but is of vital importance in planning a surgical approach. The authors examined the differences between DAWs and idiopathic SCH on MRI and CT myelography to improve diagnostic confidence prior to surgery.

METHODS

Review of the picture archiving and communication system (PACS) database between 2005 and 2015 identified 6 patients with DAW and 5 with SCH. Clinical data including demographic information, presenting symptoms and neurological signs, and surgical reports were collected from the electronic medical records. Ten of the 11 patients underwent MRI. CT myelography was performed in 3 patients with DAW and in 1 patient with SCH. Imaging studies were analyzed by 2 board-certified neuroradiologists for the following features: 1) location of the deformity; 2) presence or absence of cord signal abnormality or syringomyelia; 3) visible arachnoid web; 4) presence of a dural defect; 5) nature of dorsal cord indentation (abrupt “scalpel sign” vs “C”-shaped); 6) focal ventral cord kink; 7) presence of the nuclear trail sign (endplate irregularity, sclerosis, and/or disc-space calcification that could suggest a migratory path of a herniated disc); and 8) visualization of a complete plane of CSF ventral to the deformity.

RESULTS

The scalpel sign was positive in all patients with DAW. The dorsal indentation was C-shaped in 5 of 6 patients with SCH. The ventral subarachnoid space was preserved in all patients with DAW and interrupted in cases of SCH. In no patient was a web or a dural defect identified.

CONCLUSIONS

DAW and SCH can be reliably distinguished on imaging by scrutinizing the nature of the dorsal indentation and the integrity of the ventral subarachnoid space at the level of the cord deformity.

Transforaminal epidural blood patch for intractable spontaneous cerebrospinal fluid leak: a case report

Background

Epidural blood patch (EBP) is a recognized treatment for spontaneous cerebrospinal fluid leak (SCFL) and is typically administered by the interlaminar approach. Here, we report a case of a patient in whom SCFL failed to resolve after three applications of interlaminar EBPs before finally being successfully treated with transforaminal EBP.

Case presentation

We report a case of a 41-year-old female with a definitive diagnosis of SCFL according to computed tomography (CT) myelography. A fluoroscopy-guided interlaminar EBP was applied three times without resolution of her orthostatic headache. A second myelography was therefore performed demonstrating a leak point on the ventral side of the dura mater. To close the ruptured ventral dura mater, it was necessary to fill the ventral epidural space with blood. Therefore, transforaminal EBP was performed. On spinal CT performed immediately after treatment, the ventral epidural space was observed to be filled with injected blood. Her headache improved the following day, and her symptoms completely subsided after 5 days.

Conclusion

Transforaminal epidural blood patch is appropriate for patients with intractable cerebrospinal fluid leak. Patients with cerebrospinal fluid leakage due to rupture of the ventral side of the dura mater may be particularly good candidates for this procedure.

Vanishing calcification associated with a spontaneous ventral spinal cerebrospinal fluid leak

Background

Some patients with spontaneous intracranial hypotension have a ventral spinal cerebrospinal fluid (CSF) leak and these CSF leaks may be associated with calcified disk herniations. Identifying these calcifications is helpful in directing treatment. We report here the unusual case of a patient with a ventral CSF leak in whom the associated calcification absorbed over a five-month period.

Case report

A 42-year-old woman developed orthostatic headaches and bilateral abducens nerve palsies. Magnetic resonance imaging of her brain showed typical findings of spontaneous intracranial hypotension. Magnetic resonance imaging of her spine showed an extensive cervicothoracic CSF leak. Computed tomographic myelography showed calcification at the Th1–2 disk space. Three epidural blood patches were performed, but her symptoms persisted. Digital subtraction myelography performed five months later showed an upper thoracic ventral CSF, but the calcification was no longer present. A dural tear, found at surgery at the Th1–2 level, was repaired and the patient made an uneventful recovery.

Discussion

The resorption of calcifications at the level of a ventral spinal CSF leak could explain the absence of any calcifications in at least some patients with such leaks and demonstrates the usefulness of reviewing previous imaging in patients with ventral CSF leaks if the exact site of the leak remains unknown.

CT Fluoroscopy-Guided Blood Patching of Ventral CSF Leaks by Direct Needle Placement in the Ventral Epidural Space Using a Transforaminal Approach

BACKGROUND AND PURPOSE

Epidural blood patch treatment of spontaneous intracranial hypotension arising from ventral CSF leaks can be difficult secondary to challenges in achieving ventral spread of patching material. The purpose of this study was to determine the technical success rates and safety profile of direct needle placement into the ventral epidural space via a posterior transforaminal approach.

MATERIALS AND METHODS

We retrospectively reviewed consecutive CT fluoroscopy-guided epidural blood patches from June 2013 through July 2015. Cases were included if a posterior transforaminal approach was taken to place the needle directly in the ventral epidural space. Rates of technical success (defined as contrast in the spinal canal ventral epidural space) and optimal epidurogram (defined as contrast spreading into or beyond the middle third of the spinal canal ventral epidural space) were determined. Factors influencing these rates were assessed. All complications, inadvertent intravascular injections, and intrathecal punctures were recorded.

RESULTS

A total of 72 ventral epidural blood patches were identified; immediate technical success was achieved in 95.8% and an optimal epidurogram in 47.2%. Needle position within the spinal canal ventral epidural space was associated with obtaining an optimal epidurogram (P = .005). Inadvertent intravascular injection was identified in 29.3% of cases, but all were venous. There were no inadvertent intrathecal punctures or complications.

CONCLUSIONS

Direct needle placement in the ventral epidural space via a transforaminal approach for treatment of ventral CSF leaks has an excellent technical success rate and safety profile. This technique can be considered as a treatment option in selected patients with ventral CSF leaks for whom traditional techniques are unsuccessful.

Uncommon Manifestations of Intervertebral Disk Pathologic Conditions

Beyond the familiar disk herniations with typical clinical features, intervertebral disk pathologic conditions can have a wide spectrum of imaging and clinical manifestations. The goal of this review is to illustrate and discuss unusual manifestations of intervertebral disk pathologic conditions that radiologists may encounter, including disk herniations in unusual locations, those with atypical imaging features, and those with uncommon pathophysiologic findings. Examples of atypical disk herniations presented include dorsal epidural, intradural, symptomatic thoracic (including giant calcified), extreme lateral (retroperitoneal), fluorine 18 fluorodeoxyglucose-avid, acute intravertebral (Schmorl node), and massive lumbar disk herniations. Examples of atypical pathophysiologic conditions covered are discal cysts, fibrocartilaginous emboli to the spinal cord, tiny calcified disks or disk-level spiculated osteophytes causing spinal cerebrospinal fluid (CSF) leak and intracranial hypotension, and pediatric acute calcific discitis. This broad gamut of disease includes a variety of sizes of disk pathologic conditions, from the tiny (eg, the minuscule calcified disks causing high-flow CSF leaks) to the extremely large (eg, giant calcified thoracic intradural disk herniations causing myelopathy). A spectrum of clinical acuity is represented, from hyperacute fibrocartilaginous emboli causing spinal cord infarct, to acute Schmorl nodes, to chronic intradural herniations. The entities included are characterized by a range of clinical courses, from the typically devastating cord infarct caused by fibrocartilaginous emboli, to the usually spontaneously resolving pediatric acute calcific discitis. Several conditions have important differential diagnostic considerations, and others have relatively diagnostic imaging findings. The pathophysiologic findings are well understood for some of these entities and poorly defined for others. Radiologists' knowledge of this broad scope of unusual disk disease is critical for accurate radiologic diagnoses. Online supplemental material is available for this article. (©)RSNA, 2016.

Spinal cord herniation with characteristic bone change: a case report

Spinal cord herniation (SCH) is a rare disease characterized by herniation of the thoracic spinal cord through an anterior dural defect, presenting with progressive myelopathy. A case of a 69-year-old woman who presented with Brown-Sequard syndrome and a bone defect, in which an osteophyte created a hemisphere-like cavity with spinal cord herniation, is presented. The strangled spinal cord was released, and the defect was closed microsurgically using an artificial dural patch to prevent re-herniation. Postoperatively, the patient experienced gradual improvement in neurologic function. The SCH mechanism and surgical strategy are discussed.

Ultrafast dynamic computed tomography myelography for the precise identification of high-flow cerebrospinal fluid leaks caused by spiculated spinal osteophytes

OBJECT

Precise localization and understanding of the origin of spontaneous high-flow spinal CSF leaks is required prior to targeted treatment. This study demonstrates the utility of ultrafast dynamic CT myelography for the precise localization of high-flow CSF leaks caused by spiculated spinal osteophytes.

METHODS

This study reports a series of 14 patients with high-flow CSF leaks caused by spiculated spinal osteophytes who underwent ultrafast dynamic CT myelography between March 2009 and December 2010. There were 10 male and 4 female patients, with an average age of 49 years (range 37–74 years). The value of ultrafast dynamic CT myelography in depicting the CSF leak site was qualitatively assessed.

RESULTS

In all 14 patients, ultrafast dynamic CT myelography was technically successful at precisely demonstrating the site of the CSF leak, the causative spiculated osteophyte piercing the dura, and the relationship of the implicated osteophyte to adjacent structures. Leak sites included 3 cervical, 11 thoracic, and 0 lumbar levels, with 86% of the leaks occurring from C-5 to T-7. Information obtained from the ultrafast dynamic CT myelogram was considered useful in all treated CSF leaks.

CONCLUSIONS

Spinal osteophytes piercing the dura are a more frequent cause of high-flow CSF leaks than previously recognized. Ultrafast dynamic CT myelography adds value beyond standard dynamic myelography or digital subtraction myelography in the diagnosis and anatomical characterization of high-flow spinal CSF leaks caused by these osteophytes. This information allows for appropriate planning for percutaneous or surgical treatment.

Idiopathic spinal cord herniation with duplicated dura mater and dorsal subarachnoid septum. Report of a case and review of the literature

Background

Idiopathic spinal cord herniation (ISCH) is a rare condition and its pathogenesis remains unclear. The purpose of this case report is to present an ISCH case with dorsal subarachnoid septum suggesting the pathogenesis of ISCH being adhesions from preexisting inflammation.

Methods

Single case report.

Results

A 60-year-old woman presented with Brown-Séquard syndrome below the level of T6. Magnetic resonance imaging revealed the thoracic spinal cord was displaced ventrally, and the dorsal subarachnoid space was enlarged and had a septum between the spinal cord and dura mater. Intraoperatively, the dorsal dura mater was seen to be adherent and the subarachnoid septum was identified after durotomy. The inner layer defect of the duplicated dura mater was found in the ventral dura mater, through which the spinal cord had herniated. After releasing the septum, the adhesions around the dura mater, and the hiatus, the spinal cord was reduced.

Conclusions

The present case indicates that adhesions around the dura mater can be the pathogenesis of ISCH.

Focal anterior displacement of the thoracic spinal cord without evidence of spinal cord herniation or an intradural mass

OBJECTIVE

We report magnetic resonance imaging (MRI) findings on focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass.

MATERIALS AND METHODS

We identified 12 patients (male:female = 6:6; mean age, 51.7; range, 15-83 years) between 2007 and 2011, with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MRI findings in consensus.

RESULTS

An asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord in all patients, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (thoracic vertebrae 1-6). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and they showed no focal T2-hyperintensity in the spinal cord with the exception of one patient. In addition, cerebrospinal fluid (CSF) flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. Computed tomography myelography revealed preserved CSF flow in the two available patients.

CONCLUSION

Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass.

Spinal manifestations of spontaneous intracranial hypotension

Object

The goal of the study was to elucidate the spinal manifestations of spontaneous intracranial hypotension.

Methods

The authors reviewed the medical records and imaging studies of 338 consecutive patients with spontaneous intracranial hypotension who were evaluated at their institution between 2001 and 2010.

Results

Twenty patients (6%; mean age 35.8 [range 16 to 60 years]; 5 males and 15 females) had convincing signs or symptoms referable to the spinal cord or spinal nerve roots. The spinal manifestations consisted of radiculopathy in 11 patients (unilateral in 8 and bilateral in 3), myelopathy in 8 patients, and bibrachial amyotrophy in 1 patient. The cervical spine was involved in 12 patients, the thoracic spine in 5, and the lumbosacral spine in 3. The spinal symptoms were positional in only 3 patients. The spinal manifestations occurred around the time of the headache onset in 16 patients, and months to years after the positional headache had resolved in 4 patients. A large extrathecal CSF collection causing compression of the spinal cord or nerve root was responsible for the spinal manifestations in the majority of patients. Treatment of the spinal CSF leak resulted in resolution of the spinal manifestations along with the headache, except for those in the patient with bibrachial amyotrophy.

Conclusions

Spinal manifestations are uncommon in cases of spontaneous intracranial hypotension, occurring in about 6% of patients, but myelopathy and radiculopathy involving all spinal segments do occur. Unlike the headache, the spinal manifestations usually are not positional and are caused by mass effect from an extradural CSF collection.