Microsurgical Repair of Ventral Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension: Efficacy and Safety of Patch-Sealing Versus Suturing

BACKGROUND AND OBJECTIVES

In patients with spontaneous intracranial hypotension (SIH), microsurgical repair is recommended in Type 1 (ventral) dural leaks, when conservative measures fail. However, there is lacking consensus on the optimal surgical technique for permanent and safe closure of ventral leaks.

METHODS

We performed a retrospective analysis of surgically treated SIH patients with Type 1 leaks at our institution between 2013 and 2023. Patients were analyzed according to the type of surgical technique: (1) Microsurgical suture vs (2) extradural and intradural patching (sealing technique). End points were resolution of spinal longitudinal epidural cerebrospinal fluid collection (SLEC), change in brain SIH-Score (Bern-Score), headache resolution after 3 months, surgery time, complications, and reoperation rates.

RESULTS

In total, 85 (66% women) patients with consecutive SIH (mean age 47 ± 11 years) underwent transdural microsurgical repair. The leak was sutured in 53 (62%) patients (suture group) and patch-sealed in 32 (38%) patients (sealing group). We found no significant difference in the rates of residual SLEC and resolution of headache between suture and sealing groups (13% vs 22%, P = .238 and 89% vs 94%, P = .508). No changes were found in the postoperative Bern-Score between suture and sealing groups (1.4 [±1.6] vs 1.7 [±2.1] P = 1). Mean surgery time was significantly shorter in the sealing group than in the suture group (139 ± 48 vs 169 ± 51 minutes; P = .007). Ten patients of the suture and 3 of the sealing group had a complication (23% vs 9%, P = .212), whereas 6 patients of the suture and 2 patients of the sealing group required reoperation (11% vs 6%, P = .438).

CONCLUSION

Microsurgical suturing and patch-sealing of ventral dural leaks in patients with SIH are equally effective. Sealing alone is a significantly faster technique, requiring less spinal cord manipulation and may therefore minimize the risk of surgical complications.

Perspectives from the Inaugural "Spinal CSF Leak: Bridging the Gap" Conference: A Convergence of Clinical and Patient Expertise

BACKGROUND AND PURPOSE

The inaugural "Spinal CSF Leak: Bridging the Gap" Conference was organized to address the complexities of diagnosing and treating spinal CSF leaks. This event aimed to converge the perspectives of clinicians, researchers, and patients with a patient-centered focus to explore the intricacies of spinal CSF leaks across 3 main domains: diagnosis, treatment, and aftercare.

MATERIALS AND METHODS

Physician and patient speakers were invited to discuss the varied clinical presentations and diagnostic challenges of spinal CSF leaks, which often lead to misdiagnosis or delayed treatment. Patient narratives were interwoven with discussions on advanced radiologic techniques and clinical assessments. Treatment-focused sessions highlighted patient experiences with various therapeutic options, including epidural blood patches, surgical interventions, and percutaneous and endovascular therapies. The intricacies of immediate and long-term postprocedural management were explored.

RESULTS

Key outcomes from the conference included the recognition of the need for increased access to specialized CSF leak care for patients and heightened awareness among health care providers, especially for atypical symptoms and presentations. Discussions underscored the variability in individual treatment responses and the necessity for personalized diagnostic and treatment algorithms. Postprocedural challenges such as managing incomplete symptom relief and rebound intracranial hypertension were also addressed, emphasizing the need for effective patient monitoring and follow-up care infrastructures.

CONCLUSIONS

The conference highlighted the need for adaptable diagnostic protocols, collaborative multidisciplinary care, and enhanced patient support. These elements are vital for improving the recognition, diagnosis, and management of spinal CSF leaks, thereby optimizing patient outcomes and quality of life. The event established a foundation for future advancements in spinal CSF leak management, advocating for a patient-centered model that harmonizes procedural expertise with an in-depth understanding of patient experiences.

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.

Indirect Fistula: A New Terminology for Cerebrospinal Fluid Fistula With Different 'Apparent Origin' and 'Real Origin'

Fistulas are abnormal communications between body cavities. They can occur between the CNS and the extracranial space, presenting clinically as CSF leaks. Due to the variety of features, multiple classifications have been implemented to better study this pathology. A systematic review was conducted using the Scopus, Medline, and Web of Science databases. Observational studies such as cohort studies, case reports, case series, cross-sectional studies, systematic reviews, and publications that assess the classification of CSF leaks were included. The systematic review identified 29 publications that met the required criteria for inclusion. Although the primary focus of most of these publications was not on classification, they briefly mentioned it. The included publications describe classifications according to etiology, exiting flow pressure, anatomic site, and some new classification proposals. Of the 29 included studies, 11 referred to the appearance of CSF rhinorrhea or otorrhea with no relationship between the cause or site of origin and the site of the CSF leak. However, none of these publications names this situation. These results clearly indicate that a term for this circumstance needs to be established; none of the previously listed publications provide a name for this condition. This systematic review aims to demonstrate the necessity of implementing a new term to describe CSF leaks where the 'apparent origin' does not correspond to the 'real origin.' The results show no existing term that considers such cases; therefore, we propose the term 'Indirect Fistula' to designate these cases.

Spontaneous Intracranial Hypotension: Case Report and Update on Diagnosis and Treatment

Spontaneous intracranial hypotension (SIH) is an important cause of daily headaches that occur in young and middle-aged, active persons and is often misdiagnosed, leading to prolonged inactivity and rather high healthcare expenditures. Its diagnosis requires a high degree of clinical suspicion and careful interpretation of imaging studies. We present a case of SIH, which was successfully treated but which posed serious diagnostic challenges, ranging from cerebro-vascular disease and meningitis to granulomatous diseases, and for whom every therapeutic attempt just worsened the patient's condition until we finally reached the correct diagnosis. To raise awareness of this condition, we also present an updated overview of the clinical picture, evaluation, and treatment options for SIH.

Posterior Transdural Repair of a Spontaneous Ventral Thoracic Cerebrospinal Fluid Leak: 2-Dimensional Operative Video

Spontaneous intracranial hypotension is a rare but serious condition characterized by orthostatic headaches and a variety of neurological symptoms. 1,2 Spontaneous intracranial hypotension should be considered in all patients with new onset, daily, persistent headaches, and orthostatic symptoms. It is typically caused by spontaneous spinal cerebrospinal fluid (CSF) leaks. 1,2 Traditional first-line treatments include hydration, bedrest, epidural blood patches, and fibrin glue injections. However, refractory cases often require surgical intervention, especially those caused by a small ventral osteophyte, which is classified as a type 1 leak. 3-5 The small osteophyte causes a tear in the dura of the ventral canal, usually near the cervicothoracic junction. Diagnosis of these leaks is challenging because these small osteophytes can also occur asymptomatically, or patients may have several of them at multiple levels. Typically, dynamic myelography is needed for accurate localization due to the inadequacy of standard imaging. 6 This video details a young patient with refractory spontaneous intracranial hypotension from a type 1 spontaneous CSF leak, treated successfully using a posterior transdural surgical approach with spinal cord mobilization. Our video presentation outlines the surgical technique and provides an overview of this underdiagnosed condition. Our described approach offers direct visualization, suturing of the leak site, and a multilayer repair without the need for spinal fusion. It also avoids the morbidity to the neck, chest, and mediastinal structures that is at risk with lateral or anterior approaches. A combined intradural and extradural repair may enhance the durability of repair for ventral CSF leaks. The patient consented to the procedure. This operative video did not require Institutional Review Board approval as all patient information has been anonymized, ensuring no identifiable information is disclosed. The video is a single case that does not involve interventions or pose risks beyond standard care, adhering to ethical guidelines and institutional policies.

Impact of Spinal CSF Leaks on Quality of Life and Mental Health and Long-Term Reversal by Surgical Closure

Background and Objectives

Spontaneous intracranial hypotension (SIH) caused by a spinal CSF leak is a multisymptom syndrome, which can dramatically affect physical and mental health. However, systematic data on health-related quality of life (HRQoL) and mental health are scarce. We hypothesized that surgical treatment leads to significant and sustained improvements in HRQoL and mental health in patients with SIH.

Methods

In this single-center cohort study, we prospectively collected HRQoL and mental health data in patients undergoing surgical closure of a spinal CSF leak from September 2020 to November 2022. EuroQoL (EQ-5D-5L), including the health state index (EQ-Index) and the visual analog scale (EQ-VAS), measured HRQoL. The 21-item version of the Depression Anxiety Stress Scales (DASS-21) measured symptoms of mental health. Follow-ups were performed 3 and 6 months postoperatively. Primary outcome was the change in EQ-Index, EQ-VAS, and DASS-21 subscales. Secondary outcome was the impact of baseline depression symptoms on HRQoL outcomes following surgery.

Results

Seventy-four patients were included. EQ-VAS improved from 40 (interquartile range [IQR] 30-60) preoperatively to 70 (IQR 55-85) at 3 months and to 72 (IQR 60-88) at 6 months postoperatively (p < 0.001, respectively). EQ-Index increased from 0.683 (IQR 0.374-0.799) to 0.877 (0.740-0.943) at 3 months and to 0.907 (0.780-0.956) at 6 months postoperatively (p < 0.001, respectively). Depression, anxiety, and stress significantly improved after surgery. Preoperative depressive symptoms did not affect the HRQoL outcome.

Discussion

The severe impact of a spinal CSF leak on HRQoL and mental health significantly improved after closure of the leak. Higher levels of depressive symptoms do not predict worse outcomes and should not discourage invasive treatment. Further systematic evaluation of outcomes, with special regard to quality of life, is needed, as it allows a comparison of symptom burden between SIH and more familiar diseases as well as a comparison of different treatment modalities in future studies.

Targeted Epidural Blood Patch Injection Through a Mini-Open Approach for Treatment of Spontaneous Intracranial Hypotension

BACKGROUND AND OBJECTIVES

Spontaneous intracranial hypotension is recognized as a cause for refractory headache. Treatment can range from blind blood patch injection to microsurgical repair of the cerebrospinal fluid (CSF) leak. The objective of the study was to investigate the safety and efficacy of the targeted blood patch injection (TBPI) technique through a mini-open approach in treatment of refractory intracranial hypotension.

METHODS

We retrospectively reviewed cases of 20 patients who were treated for spontaneous intracranial hypotension at our institute between 2011 and 2022. Head and spine MRI and whole-spine myelography were performed in an attempt to localize the CSF leak. All patients underwent implantation of two epidural drains above and beneath the index level through a minimally invasive interlaminar microsurgical approach under general anesthesia. Then, blood patch was injected under clinical surveillance. Treatment success and surgical complications were evaluated postoperatively and at follow-up.

RESULTS

Patients presented with orthostatic headache, vertigo, sensory deficits, and hypacusis (95%, 15%, 15%, and 10%, respectively). Subdural effusions were present in 65% of the cases. A CSF leak was identified in all patients. The exact site of the CSF leak could be identified in 80% of cases. TBPI was performed with an average blood amount of 37.5 mL. A significant improvement of symptoms was reported in 90% of the cases. A total of 15% of the patients showed recurrent symptoms and underwent a second TBPI, resulting in symptom relief. No therapy-related complications were reported.

CONCLUSION

TBPI is a safe and efficient treatment for spontaneous intracranial hypotension. It is performed in a minimally invasive procedure and can be repeated, if necessary, with a very low-risk profile.

Percutaneous Treatment and Post-treatment Management of CSF Leaks and CSF-Venous Fistulas in Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension (SIH) is a treatable cause of orthostatic headaches secondary to pathologic loss of cerebrospinal fluid (CSF) from the subarachnoid space. SIH has several known pathologic causes including dural tears from disc osteophytes, leaks emanating from nerve root sleeve diverticula, and CSF-venous fistulas (CVFs). Depending on the type of leak, surgical repair or endovascular techniques may be options for definite treatment. However, epidural blood patching (EBP) remains first-line therapy for many patients due to its long track record, broad availability, and relatively lower risk profile. This review focuses on indications and techniques for the percutaneous treatment of SIH and provides an overview of post-procedural management of these patients.

Distinct Pattern of Membrane Formation With Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension

BACKGROUND AND OBJECTIVES

To systematically describe pertinent, intraoperative anatomic findings encountered when approaching spinal cerebrospinal fluid (CSF) leaks and CSF-venous fistulas in spontaneous intracranial hypotension (SIH).

METHODS

In a retrospective study, we included surgically treated patients suffering from SIH at our institution from April 2018 to March 2022. Anatomic, intraoperative data were extracted from operative notes and supplemented with data from surgical videos and images. Prominent anatomic features were compared among different types of CSF leaks.

RESULTS

The study cohort consists of 120 patients with a mean age of 45.2 years. We found four distinct patterns of spinal membranes specifically associated with different types of CSF leaks: (i) thick, dorsal membranes, which were hypervascular and may mimic the dura (pseudodura); (ii) thin, lateral membranes encapsulating a ventral epidural CSF compartment (confining the spinal longitudinal extradural CSF collection); (iii) ventral membranes constituting a transdural funnel-like CSF channel; and (iv) lateral membranes forming spinal cysts/meningeal diverticulae associated with lateral CSF leaks. The latter three types resemble a layer of arachnoid herniated through the dural defect.

CONCLUSION

We describe four distinct spinal (neo-)membranes in association with spinal CSF leaks. Formation of these membranes, or emergence by herniation of arachnoid through a dural defect, constitutes a specific pathoanatomic feature of patients with SIH and CSF leaks. Recognition of these membranes is of paramount importance for diagnosis and treatment of patients with spinal CSF leaks.

Patient-reported symptomatology and its course in spontaneous intracranial hypotension - Beware of a chameleon

OBJECTIVE

Although orthostatic headache is the hallmark symptom of spontaneous intracranial hypotension (SIH), patients can present with a wide range of different complaints and thereby pose a diagnostic challenge for clinicians. Our aim was to describe and group the different symptoms associated with SIH and their course over time.

METHODS

We retrospectively surveyed consecutive patients diagnosed and treated for SIH at our institution from January 2013 to May 2020 with a specifically designed questionnaire to find out about their symptomatology and its course.

RESULTS

Of 112 eligible patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 67 (84.8%) reported initial orthostatic headaches, whereas 12 (15.2%) denied having this initial symptom. All except one (98.7%) patients reported additional symptoms: most frequently cephalic pressure (69.6%), neck pain (68.4%), auditory disturbances (59.5%), nausea (57%), visual disturbances (40.5%), gait disturbance (20.3%), confusion (10.1%) or sensorimotor deficits (21.5%). Fifty-seven (72.2%) patients reported a development of the initial symptoms predominantly in the first three months after symptom onset. Age and sex were not associated with the symptomatology or its course (p > 0.1).

CONCLUSION

Although characteristic of SIH, a relevant amount of patients present without orthostatic headaches. In addition, SIH can manifest with non-orthostatic headaches at disease onset or during the course of the disease. Most patients report a wide range of associated complaints. A high degree of suspicion is crucial for an early diagnosis and targeted treatment.

Efficacy of Epidural Blood Patching or Surgery in Spontaneous Intracranial Hypotension: A Systematic Review and Evidence Map

BACKGROUND

Spontaneous intracranial hypotension is an important cause of treatable secondary headaches. Evidence on the efficacy of epidural blood patching and surgery for spontaneous intracranial hypotension has not been synthesized.

PURPOSE

Our aim was to identify evidence clusters and knowledge gaps in the efficacy of treatments for spontaneous intracranial hypotension to prioritize future research.

DATA SOURCES

We searched published English language articles on MEDLINE (Ovid), the Web of Science (Clarivate), and EMBASE (Elsevier) from inception until October 29, 2021.

STUDY SELECTION

We reviewed experimental, observational, and systematic review studies assessing the efficacy of epidural blood patching or surgery in spontaneous intracranial hypotension.

DATA ANALYSIS

One author performed data extraction, and a second verified it. Disagreements were resolved by consensus or adjudicated by a third author.

DATA SYNTHESIS

One hundred thirty-nine studies were included (median, 14 participants; range, 3-298 participants). Most articles were published in the past decade. Most assessed epidural blood patching outcomes. No studies met level 1 evidence. Most were retrospective cohort or case series (92.1%, n = 128). A few compared the efficacy of different treatments (10.8%, n = 15). Most used objective methods for the diagnosis of spontaneous intracranial hypotension (62.3%, n = 86); however, 37.7% (n = 52) did not clearly meet the International Classification of Headache Disorders-3 criteria. CSF leak type was unclear in 77.7% (n = 108). Nearly all reported patient symptoms using unvalidated measures (84.9%, n = 118). Outcomes were rarely collected at uniform prespecified time points.

LIMITATIONS

The investigation did not include transvenous embolization of CSF-to-venous fistulas.

CONCLUSIONS

Evidence gaps demonstrate a need for prospective study designs, clinical trials, and comparative studies. We recommend using the International Classification of Headache Disorders-3 diagnostic criteria, explicit reporting of CSF leak subtype, inclusion of key procedural details, and using objective validated outcome measures collected at uniform time points.

Intraoperative Visualization of Flow in Direct Cerebrospinal Fluid-Venous Fistulas Using Intrathecal Fluorescein

BACKGROUND

Cerebrospinal fluid-venous fistulas (CVFs) are a rare cause of spontaneous intracranial hypotension. Intraoperatively, CVFs are not readily identifiable and difficult to differentiate from normal veins.

OBJECTIVE

To assess the utility of intrathecal fluorescein injection intraoperatively to visualize and identify the CVF.

METHODS

We report a case series of patients treated surgically for a CVF. After surgical exposure, we injected intrathecal fluorescein (5-10 mg) through a lumbar catheter, which we placed immediately before surgery.

RESULTS

Four patients with spontaneous intracranial hypotension with a suspected CVF underwent surgical ligation with adjunctive intrathecal fluorescein application. Intraoperative fluorescein injection confirmed the presence of a CVF in 3 cases. In 2 cases, we observed rapid fluorescein filling of a single epidural vein constituting the CVF. Other epidural vessels did not fill with fluorescein. In 1 case, fluorescein helped to identify a residual CVF after previous incomplete embolization. In the fourth case, no CVF was found intraoperatively. By contrast, a meningeal nerve root diverticulum was visualized, wrapped, and clipped.

CONCLUSION

We demonstrate for the first time the direct intraoperative visualization of CVF using intrathecal fluorescein. CVF can be identified intraoperatively using fluorescein dye, which can be a valuable adjunct for the surgeon confronted with this disease.

Idiopathic Ventral Spinal Cord Hernia-A Single-Center Case Series of 11 Patients

BACKGROUND

Idiopathic spinal cord herniations (ISCH) are rare defects of the ventromedial or mediolateral dura mater with herniation of the spinal cord through the defect with approximately 350 described cases worldwide. Patients usually become symptomatic with motor or sensory neurological deficits and gait disturbances.

OBJECTIVE

To describe characteristic symptoms and clinical findings and to evaluate the postoperative course and outcomes of ISCH.

METHODS

We present a single-center data analysis of a case series of 11 consecutive patients who were diagnosed with ISCH and underwent surgery in our department between 2009 and 2021.

RESULTS

All herniations were located in the thoracic spine between T2 and T9. In most cases, gait ataxia and dysesthesia led to further workup and subsequently to the diagnosis of ISCH. A "far-enough" posterior-lateral surgical approach, hemilaminectomy or laminectomy with a transdural approach, was performed under intraoperative neurophysiological monitoring which was followed by adhesiolysis, repositioning of the spinal cord and sealing using a dura patch. After surgery, clinical symptoms improved in 9 of 11 patients (81.8%), while only 1 patient experienced deterioration of symptoms (9.1%) and 1 patient remained equal (9.1%). The median preoperative McCormick grade was 3 (±0.70), while the median postoperative grade was 2 (±0.98) ( P = .0047).

CONCLUSION

In our case series of ISCH, we found that in most patients, neurological deficits improved postoperatively. This indicates that surgery in ISCH should not be delayed in symptomatic patients.

Minimally invasive surgery for spinal cerebrospinal fluid leaks in spontaneous intracranial hypotension

OBJECTIVE

Spinal CSF leaks cause spontaneous intracranial hypotension (SIH). Surgical closure of spinal CSF leaks is the treatment of choice for persisting leaks. Surgical approaches vary, and there are no studies in which minimally invasive techniques were used. In this study, the authors aimed to detail the safety and feasibility of minimally invasive microsurgical sealing of spinal CSF leaks using nonexpandable tubular retractors.

METHODS

Consecutive patients with SIH and a confirmed spinal CSF leak treated at a single institution between April 2019 and December 2020 were included in the study. Surgery was performed via a dorsal 2.5-cm skin incision using nonexpandable tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach. The primary outcome was successful sealing of the dura, and the secondary outcome was the occurrence of complications.

RESULTS

Fifty-eight patients, 65.5% of whom were female (median age 46 years [IQR 36-55 years]), with 38 ventral leaks, 17 lateral leaks, and 2 CSF venous fistulas were included. In 56 (96.6%) patients, the leak could be closed, and in 2 (3.4%) patients the leak was missed because of misinterpretation of the imaging studies. One of these patients underwent successful reoperation, and the other patient decided to undergo surgery at another institution. Two other patients had to undergo reoperation because of insufficient closure and a persisting leak. The rate of permanent neurological deficit was 1.7%, the revision rate for a persisting or recurring leak was 3.4%, and the overall revision rate was 10.3%. The rate of successful sealing during the primary closure attempt was 96.6% and 3.4% patients needed a secondary attempt. Clinical short-term outcome at discharge was unchanged in 14 patients and improved in 25 patients, and 19 patients had signs of rebound intracranial hypertension.

CONCLUSIONS

Minimally invasive surgery with tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach is safe and effective for the treatment of spinal CSF leaks. The authors suggest performing a minimally invasive closure of spinal CSF leaks in specialized centers.

Intraoperative Motor Evoked Responses to Double-Train Paradigm Stimulation for Guiding Lead Placement and Postoperative Programming in Spinal Cord Stimulation for Pain

OBJECTIVE

We aimed to demonstrate the feasibility of using motor evoked responses to intraoperative double-train stimulation to guide lead placement and matching of intraoperative contacts with postoperative electrode programming in spinal cord stimulation for pain performed under general anesthesia.

MATERIALS AND METHODS

The study included a series of 20 consecutive patients with refractory pain operated on under general anesthesia. Either percutaneous or paddle leads were implanted and positioned according to the intraoperative mapping results. Neurophysiologic mapping was performed with a double-train stimulation paradigm (intertrain interval of 60 milliseconds, three to five cathodal pulses with 0.5-millisecond pulse duration, and within-train interstimulus intervals of 2-4 milliseconds). The sites where dorsal column responses of the targeted dermatomes were detected were considered optimal for lead placement (intraoperative best contacts). Following spinal cord stimulator (SCS) lead placement, blinded postoperative programming of electrode contacts was matched with the intraoperative best contacts and the pain-paresthesia overlap for the trial phase. A binominal test was used as a statistical method; pre- and postoperative numeric rating scale (NRS) after three months was obtained.

RESULTS

A total of 15 patients underwent spinal cord stimulation trial for intractable pain. Of these, ten patients (66%) had a successful trial and received permanent implants; one patient had a successful trial but was never intended to be implanted because of her poor health condition; four patients (26%) had an unsuccessful trial, leading to trial electrode explantation; and five patients had already had an implant with percutaneous leads and therefore underwent electrode revision, of whom four patients received paddle leads. In 18 of the 20 operated patients (90%), we found a match between the best intraoperative contacts and the postoperatively programmed contacts (significantly better than chance, p = 8.2 × 10^-15). In 90% of the patients, a pain-paresthesia overlap of 100% was found. In the remaining two patients (10%), the postoperatively best programmed contacts were one contact away from the intraoperative neurophysiologic best contact. A mean preoperative NRS score of 8.2 (variance) and a mean follow-up NRS score after three months of 3.6 (variance) were obtained for all patients with implants.

CONCLUSION

In this proof-of-concept study, we were able to demonstrate that SCS lead placement using a double-train stimulation paradigm performed under general anesthesia is a safe and feasible technique, offering reliable prediction of contacts for postoperative programming and excellent pain-paresthesia coverage.

[Spontaneous dural CSF fistula as a cause of intracranial hypotension syndrome. Case report and literature review]

Typical symptoms of spontaneous intracranial hypotension syndrome are severe headache, weakness, dizziness and inability to stay upright for a long time. Most often, this syndrome occurs due to CSF fistula in spinal space. Pathophysiology and diagnosis of this disease are poorly known for neurologists and neurosurgeons that can complicate timely surgical care. In case of correct diagnosis, we can identify the exact location of CSF fistula in 90% of cases. Treatment eliminates symptoms of intracranial hypotension and provides functional recovery. The purpose of this article is to describe the diagnostic algorithm and successful microsurgical treatment of a patient with spinal dural CSF fistula Th3-Th4 through posterolateral transdural approach.

Spinal dural cerebrospinal fluid fistula as a cause of spontaneous intracranial hypotension syndrome: Diagnosis and surgical treatment

Spontaneous intracranial hypotension (SIH) syndrome most often occurs following a cerebrospinal fluid (CSF) fistula that develops in the spinal space. Neurologists and neurosurgeons lack an understanding of the pathophysiology and diagnosis of this disease, which can make timely surgical care difficult. With the correct diagnostic algorithm, it is possible to identify the exact location of the liquor fistula in 90% of cases; subsequent microsurgical treatment can save the patient from the symptoms of intracranial hypotension and restore the ability to work. Female patient, 57 years old, was admitted with SIH syndrome. Magnetic resonance imaging (MRI) of the brain with contrast confirmed signs of intracranial hypotension. Computed tomography (CT) myelography was performed to pinpoint the location of the CSF fistula. The diagnostic algorithm and successful microsurgical treatment of a patient with spinal dural CSF fistula at the Th3-4 level using a posterolateral transdural approach. The patient was discharged on day 3 after the surgery when these complaints regressed completely. At the control examination of the patient 4 months postoperatively, there were no complaints. Identification of the cause and location of spinal the CSF fistula is a complex process that requires several stages of diagnosis. Examination of the entire back with MRI, CT myelography, or subtraction dynamic myelography is recommended. Microsurgical repair of a spinal fistula is an effective method for the treatment of SIH. The posterolateral transdural approach is effective in the repair of a spinal CSF fistula located ventrally in the thoracic spine.

Dural Entry Point of the Vertebral Artery: An Overlooked Route of Spinal CSF Leaks

Spontaneous intracranial hypotension (SIH) is no longer considered rare. Its estimated annual incidence is 5 cases per 100,000 individuals, which is half the incidence of subarachnoid hemorrhage. Epidural blood patch (EBP) is indicated for SIH patients who do not improve with conservative treatment. Accurate determination of the cerebrospinal fluid (CSF) leak site is critical for a successfully targeted EBP. We report the case of a 43-year-old woman with SIH secondary to CSF leakage at the craniovertebral junction dural entry point of the vertebral artery (VA). We treated the patient 2 months after the onset of symptoms. Fat-suppressed T2-weighted spinal magnetic resonance (MR) images revealed a massive epidural fluid collection around the upper thoracic spine. Extravasation of contrast medium through the left VA-dural entry point was clearly visible on computed tomographic myelography. A cervical EBP was injected through the C1-2 interlaminar space. The patient had a smooth recovery and was asymptomatic, with normal spinal MR findings, 6 months after treatment. The possibility of CSF leakage from the dural entry point of the VA should be considered in SIH patients. EBP targeted at the VA entry point is proposed as a safe and effective treatment.

Functional Outcome in Spinal Meningioma Surgery and Use of Intraoperative Neurophysiological Monitoring

Data on intraoperative neurophysiological monitoring (IOM) during spinal meningioma (SM) surgery are scarce. The aim of this study was to assess the role of IOM and its impact on post-operative functional outcome. Eighty-six consecutive surgically treated SM patients were included. We assessed pre and post-operative Modified McCormick Scale (mMCS), radiological and histopathological data and IOM findings. Degree of cord compression was associated with preoperative mMCS and existence of motor or sensory deficits (p < 0.001). IOM was used in 51 (59.3%) patients (IOM-group). Median pre and post-operative mMCS was II and I, respectively (p < 0.001). Fifty-seven (66.3%) patients showed an improvement of at least one grade in the mMCS one year after surgery. In the IOM group, only one patient had worsened neurological status, and this was correctly predicted by alterations in evoked potentials. Analysis of both groups found no significantly better neurological outcome in the IOM group, but IOM led to changes in surgical strategy in complex cases. Resection of SM is safe and leads to improved neurological outcome in most cases. Both complication and tumor recurrence rates were low. We recommend the use of IOM in surgically challenging cases, such as completely ossified or large ventrolateral SM.

The impact of spontaneous intracranial hypotension on social life and health-related quality of life

Objective

Spontaneous intracranial hypotension (SIH), which is often caused by a spinal cerebrospinal fluid leak, is an important cause of disabling headaches. Many patients report devastating changes in their quality of life because of their symptoms. This study aimed to evaluate the impact of SIH on patients’ social/ working life and health-related quality of life (HRQoL).

Methods

We included consecutive patients with proven SIH treated at our institution from January 2013 to May 2020. Patients were contacted and asked to complete the 15D questionnaire for the collection of HRQoL data and to provide additional information on their social life status.

Results

Of 112 patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 69 were treated surgically (87.3%), and 10 were managed non-operatively (12.7%). Twenty-five (31.6%) patients reported a severe impact on their partnership, 32 (41.5%) reported a moderate or severe impact on their social life. Forty (54.8%) patients reported sick leave for more than 3 months. The mean 15D score was 0.890 (± 0.114) and significantly impaired compared to an age- and sex-matched general population (p = 0.001), despite treatment. Patients with residual SIH-symptoms (36, 45.6%) had significantly impaired HRQoL compared to those without any residual symptoms (41, 51.9%) (p < 0.001).

Conclusion

SIH had a notable impact on the patients’ social life and HRQoL. It caused long periods of incapacity for work, and is therefore, associated with high economic costs. Although all patients were appropriately treated, reduced HRQoL persisted after treatment, underlining the chronic character of this disease.

Efficacy of epidural blood patching or surgery in spontaneous intracranial hypotension: an evidence map protocol

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a debilitating disorder caused by non-iatrogenic spinal cerebrospinal fluid leaks. SIH is increasingly recognized as an important treatable cause of secondary headaches. Treatment involves either epidural blood patching or surgery, which have considerable differences in their adverse event rates, recovery times, and cost. The objective of this evidence map is to understand the breadth of studies that investigate SIH treatment efficacy and to identify knowledge gaps to inform future research.

METHODS

This review will consider experimental, observational, and systematic review studies that assess the efficacy of epidural blood patching and surgery for the treatment of patients with SIH. Individual case studies, clinical guidelines, editorials, protocols, and studies that do not assess an intervention will not be included. English language studies will be included without limitation based on the date of publication. Databases to be searched include MEDLINE® (via Ovid), EMBASE (via Elsevier), and Web of Science™ (via Clarivate). Study selection will be performed independently by two investigators with extracted data to include study type, the number of patients included, patient descriptors, intervention characteristics, and outcome measure used. Data will be presented through a narrative summary aided by tabular and graphical formats in a manner that aligns with the objective of the evidence mapping review.

DISCUSSION

The overarching goal of this evidence map is to provide an improved understanding of the breadth of studies investigating SIH treatment efficacy in the literature and to thereby identify knowledge gaps that can inform future research directions.

TRIAL REGISTRATION

OSF Registry https://osf.io/nwju7 .

Risk Factors for Postoperative Cerebrospinal Fluid Leakage After Intradural Spine Surgery

OBJECTIVE

Well-defined risk factors for cerebrospinal fluid leakage (CSFL) after intradural spine surgery are scarce in the literature. The aim of the present study was to identify patient- and surgery-related risk factors and the incidence of CSFL.

METHODS

For the present retrospective cohort study, we identified consecutive patients who had undergone intradural spine surgery between 2009 and 2021 at our department. The primary endpoint was the incidence of clinically or radiologically proven CSFL. The effects of the clinical and surgical factors on the occurrence of CSFL were analyzed.

RESULTS

A total of 375 patients (60.3% women; mean age, 54 ± 16.5 years) were included. Of the 375 patients, 30 (8%) had experienced postoperative CSFL and, thus, a significantly greater risk of wound healing disorders (odds ratio [OR], 24.9; 95% confidence interval [CI], 9.3-66.7) and surgical site infections (OR, 8.4; 95% CI, 2.6-27.7; P < 0.01 for each). No patient-related factors were associated with the development of CSFL. Previous surgery at the index level correlated significantly with the occurrence of postoperative CSFL (OR, 2.76; 95% CI, 1.1-6.8; P = 0.03) on multivariate analysis. Furthermore, patients with intradural tumors tended to have a greater risk of CSFL (OR, 2.3; 95% CI, 0.9-5.8; P = 0.07). Surgery-related factors did not influence the occurrence of CSFL. Surgery on the thoracic spine had resulted in a significantly lower postoperative CSFL rate compared with surgery on the cervical or lumbar spine (OR, -2.5; 95% CI, 1.3-4.9; P = 0.02).

CONCLUSIONS

Our study found no modifiable risk factors for preventing CSFL after intradural spine surgery. Patients with previous surgery at the index level had a greater risk of CSFL. The occurrence of CSFL resulted in significantly more wound healing disorders and surgical site infections, necessitating further therapy.

Osseous spicules of the posterior elements causing fast cerebrospinal fluid leaks

PURPOSE

Dural tears are a common cause of spontaneous spinal CSF leaks. The majority of such leaks occur ventrally along the thecal sac, typically due to ventral osseous spicules that cause a rent in the dura. A minority of dural leaks are posterolateral in location. These leaks usually do not have an identifiable anatomic cause. We have anecdotally observed cases of posterolateral leaks caused by osseous spicules and sought to describe this phenomenon.

METHODS

We retrospectively reviewed our imaging database, searching for cases of posterolateral CSF leaks caused by osseous spicules. We identified and included three such patients and reviewed imaging and clinical information from each patient.

RESULTS

All three patients had been diagnosed using hyperdynamic CT myelography or conventional CT myelography. Their imaging showed dorsal epidural fluid collections that were related to posterolateral leaks adjacent to dorsal osseous spicules.

CONCLUSION

Dorsal osseous spicules have the potential to cause posterolateral CSF leaks.

Algorithmic Multimodality Approach to Diagnosis and Treatment of Spinal CSF Leak and Venous Fistula in Patients With Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension (SIH) is a disorder of CSF dynamics that causes a complex clinical syndrome and severe disability. SIH is challenging to diagnose because of the variability of its presenting clinical symptoms, the potential for subtle easily overlooked imaging findings, and the need for specialized diagnostic testing. Once SIH is suggested by clinical history and/or supported by initial neuroimaging, many patients may undergo initial non-targeted epidural blood patching with variable and indefinite benefit. However, data suggest that precise localization of the CSF leak or venous fistula (CVF) can lead to more effective and durable treatment strategies. Leak localization can be achieved using a variety of advanced diagnostic imaging techniques, although these may not be widely performed at non-tertiary medical centers, leaving many patients with the potential for inadequate workup or treatment. This review describes imaging techniques including dynamic fluoroscopic and CT myelography as well as delayed MR myelography, and treatment options including percutaneous, endovascular, and surgical approaches, for SIH. These are summarized by an algorithmic framework for radiologists to approach the workup and treatment of patients with suspected SIH. The importance of a multidisciplinary approach is emphasized.

Brain Spontaneous Intracranial Hypotension Score for Treatment Monitoring After Surgical Closure of the Underlying Spinal Dural Leak

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a debilitating condition requiring effective treatment; however, objective data on treatment response are scarce.

PURPOSE

To assess the suitability of the brain MRI-based SIH score (bSIH) for monitoring treatment success in SIH patients with a proven spinal cerebrospinal fluid (CSF) leak after microsurgical closure of the underlying dural breach.

METHODS

This retrospective cohort study included consecutive SIH patients with a proven spinal CSF leak, investigated at dedicated referral centre January 2012 to March 2020. The bSIH score integrates 6 imaging findings; 3 major (2 points) and 3 minor (1 point), and ranges from 0 to 9, with 0 indicating low and 9 high probability of spinal CSF loss. The score was calculated using brain magnetic resonance imaging (MRI) before and after surgical treatment of the underlying CSF leak. Headache intensity was registered on a numeric rating scale (NRS) (range 0-10).

RESULTS

In this study 52 SIH patients, 35 (67%) female, mean age 45.3 years, with a proven spinal CSF leak were included. The mean bSIH score decreased significantly from baseline to after surgical closure of the underlying dural breach (6.9 vs. 1.3, P < 0.001). A decrease in the NRS score was reported (8.6 vs. 1.2, P < 0.001).

CONCLUSION

The bSIH score is a simple tool which may serve to monitor treatment success in SIH patients after surgical closure of the underlying spinal dural leak. Its decrease after surgical closure of the underlying spinal dural breach indicates restoration of an equilibrium within the CSF compartment.

Spontaneous intracranial hypotension: the role of radiology in diagnosis and management

Spontaneous intracranial hypotension (SIH) is a condition that results from leakage of cerebrospinal fluid (CSF) from the spine, and which typically presents with debilitating orthostatic headache, but can be associated with a wide range of other symptoms. The causes of spontaneous CSF leaks that lead to SIH include dural tears, leaking meningeal diverticula, and CSF-venous fistulas. Imaging plays a central role in the initial diagnosis of SIH and in its subsequent investigation and management. This article reviews the typical neuroimaging manifestations of SIH and discusses the utility of different myelographic techniques for localising spinal CSF leaks as well as the role of image-guided treatment.

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.

Hydrocephalus Revisited: New Insights into Dynamics of Neurofluids on Macro- and Microscales

New experimental and clinical findings question the historic view of hydrocephalus and its 100-year-old classification. In particular, real-time magnetic resonance imaging (MRI) evaluation of cerebrospinal fluid (CSF) flow and detailed insights into brain water regulation on the molecular scale indicate the existence of at least three main mechanisms that determine the dynamics of neurofluids: (1) inspiration is a major driving force; (2) adequate filling of brain ventricles by balanced CSF upsurge is sensed by cilia; and (3) the perivascular glial network connects the ependymal surface to the pericapillary Virchow-Robin spaces. Hitherto, these aspects have not been considered a common physiologic framework, improving knowledge and therapy for severe disorders of normal-pressure and posthemorrhagic hydrocephalus, spontaneous intracranial hypotension, and spaceflight disease.

Spontaneous intracranial hypotension: diagnostic and therapeutic workup

Spontaneous intracranial hypotension (SIH) is an orthostatic headache syndrome with typical MRI findings among which engorgement of the venous sinuses, pachymeningeal enhancement, and effacement of the suprasellar cistern have the highest diagnostic sensitivity. SIH is in almost all cases caused by spinal CSF leaks. Spinal MRI scans showing so-called spinal longitudinal extradural fluid (SLEC) are suggestive of ventral dural tears (type 1 leak) which are located with prone dynamic (digital subtraction) myelography. As around half of the ventral dural tears are located in the upper thoracic spine, additional prone dynamic CT myelography is often needed. Leaking nerve root sleeves typically associated with meningeal diverticulae (type 2 leaks) and CSF-venous fistulas (type 3 leaks) are proven via lateral decubitus dynamic digital subtraction or CT myelography: type 2 leaks are SLEC-positive if the tear is proximal and SLEC-negative if it is distal, and type 3 leaks are always SLEC-negative. Although 30–70% of SIH patients show marked improvement following epidural blood patches applied via various techniques definite cure mostly requires surgical closure of ventral dural tears and surgical ligations of leaking nerve root sleeves associated with meningeal diverticulae or CSF-venous fistulas. For the latter, transvenous embolization with liquid embolic agents via the azygos vein system is a novel and valuable therapeutic alternative.

Outcome after surgical treatment of cerebrospinal fluid leaks in spontaneous intracranial hypotension-a matter of time

Objective

Spinal cerebrospinal fluid (CSF) leaks cause spontaneous intracranial hypotension (SIH). Microsurgery can sufficiently seal spinal CSF leaks. Yet, some patients suffer from residual symptoms. Aim of the study was to assess predictors for favorable outcome after surgical treatment of SIH.

Methods

We included consecutive patients with SIH treated surgically from January 2013 to May 2020. Subjects were surveyed by a questionnaire. Primary outcome was resolution of symptoms as rated by the patient. Secondary outcome was postoperative headache intensity on the numeric rating scale (NRS). Association between variables and outcome was assessed using univariate and multivariate regression. A cut-off value for continuous variables was calculated by a ROC analysis.

Results

Sixty-nine out of 86 patients (80.2%) returned the questionnaire and were analyzed. Mean age was 46.7 years and 68.1% were female. A significant association with the primary and secondary outcome was found only for preoperative symptom duration (p = 0.001 and p < 0.001), whereby a shorter symptom duration was associated with a better outcome. Symptom duration remained a significant predictor in a multivariate model (p = 0.013). Neither sex, age, type of pathology, lumbar opening pressure, nor initial presentation were associated with the primary outcome. ROC analysis yielded treatment within 12 weeks as a cut-off for better outcome.

Conclusion

Shorter duration of preoperative symptoms is the most powerful predictor of favorable outcome after surgical treatment of SIH. While an initial attempt of conservative treatment is justified, we advocate early definitive treatment within 12 weeks in case of persisting symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10710-7.

Microsurgical anatomy and treatment of dural defects in spontaneous spinal cerebrospinal fluid leaks

OBJECTIVE

Spontaneous spinal CSF leaks are caused by abnormalities of the spinal dura mater. Although most cases are treated conservatively or with an epidural blood patch, some intractable cases require neurosurgical treatment. However, previous reports are limited to a small number of cases. Preoperative detection and localization of spinal dural defects are difficult, and surgical repair of these defects is technically challenging. The authors present the anatomical characteristics of dural defects and surgical techniques in treating spontaneous CSF leaks.

METHODS

Among the consecutive patients who were diagnosed with spontaneous CSF leaks at the authors' institution between 2010 and 2020, those who required neurosurgical treatment were included in the study. All patients' clinical information, radiological studies, surgical notes, and outcomes were reviewed retrospectively. Outcomes of two different procedures in repairing dural defects were compared.

RESULTS

Among 77 patients diagnosed with spontaneous CSF leaks, 21 patients (15 men; mean age 57 years) underwent neurosurgery. Dural defects were detected by FIESTA MRI in 7 patients, by CT myelography in 12, by digital subtraction myelography in 1, and by dynamic CT myelography in 1. The spinal levels of the defects were localized at the cervicothoracic junction in 16 patients (76%) and thoracolumbar junction in 4 (19%). Intraoperative findings revealed that the dural defects were small, circumscribed longitudinal slits located at the ventral aspect of the dura mater. The median dural defect size was 5 × 2 mm. The presence of dural defects at the thoracolumbar junction was associated with manifestation of an altered mental status, which was an unusual manifestation of CSF leaks (p = 0.003). Eight patients were treated via the posterior transdural approach with watertight primary sutures of the ventral defects, and 13 were treated with muscle or fat grafting. Regardless of the two different procedures, postoperative MRI showed either complete disappearance or significant reduction of the extradural CSF collection. No patient experienced postoperative neurological deficits. Clinical symptoms improved or stabilized in 20 patients with a median follow-up of 12 months.

CONCLUSIONS

Dural defects in spontaneous CSF leaks were small, circumscribed longitudinal slits located ventral to the spinal cord at either the cervicothoracic or thoracolumbar junction. Muscle/fat grafting may be an alternative treatment to watertight primary sutures of ventral dural defects with a good outcome.

Clinical Presentation, Investigation Findings, and Treatment Outcomes of Spontaneous Intracranial Hypotension Syndrome: A Systematic Review and Meta-analysis

Question

What are the clinical presentation, investigation findings, and treatment outcomes of spontaneous intracranial hypotension?

Findings

This systematic review and meta-analysis of 144 articles provides a summary of the evidence on spontaneous intracranial hypotension and demonstrates that a significant minority of patients may have nonorthostatic headache, normal lumbar punctures, or normal imaging results. Treatment with 1 epidural blood patch is often successful, with large-volume blood patches giving better outcomes.

Meaning

A diagnosis of spontaneous intracranial hypotension should not be excluded based on the absence of one of its typical features; large epidural blood patches should be attempted if conservative treatment has failed.

Importance

Spontaneous intracranial hypotension (SIH) is a highly disabling but often misdiagnosed disorder. The best management options for patients with SIH are still uncertain.

Objective

To provide an objective summary of the available evidence on the clinical presentation, investigations findings, and treatment outcomes for SIH.

Data Sources

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline–compliant systematic review and meta-analysis of the literature on SIH. Three databases were searched from inception to April 30, 2020: PubMed/MEDLINE, Embase, and Cochrane. The following search terms were used in each database: spontaneous intracranial hypotension, low CSF syndrome, low CSF pressure syndrome, low CSF volume syndrome, intracranial hypotension, low CSF pressure, low CSF volume, CSF hypovolemia, CSF hypovolaemia, spontaneous spinal CSF leak, spinal CSF leak, and CSF leak syndrome.

Study Selection

Original studies in English language reporting 10 or more patients with SIH were selected by consensus.

Data Extraction and Synthesis

Data on clinical presentation, investigations findings, and treatment outcomes were collected and summarized by multiple observers. Random-effect meta-analyses were used to calculate pooled estimates of means and proportions.

Main Outcomes and Measures

The predetermined main outcomes were the pooled estimate proportions of symptoms of SIH, imaging findings (brain and spinal imaging), and treatment outcomes (conservative, epidural blood patches, and surgical).

Results

Of 6878 articles, 144 met the selection criteria and reported on average 53 patients with SIH each (range, 10-568 patients). The most common symptoms were orthostatic headache (92% [95% CI, 87%-96%]), nausea (54% [95% CI, 46%-62%]), and neck pain/stiffness (43% [95% CI, 32%-53%]). Brain magnetic resonance imaging was the most sensitive investigation, with diffuse pachymeningeal enhancement identified in 73% (95% CI, 67%-80%) of patients. Brain magnetic resonance imaging findings were normal in 19% (95% CI, 13%-24%) of patients. Spinal neuroimaging identified extradural cerebrospinal fluid in 48% to 76% of patients. Digital subtraction myelography and magnetic resonance myelography with intrathecal gadolinium had high sensitivity in identifying the exact leak site. Lumbar puncture opening pressures were low, normal (60-200 mm H₂O), and high in 67% (95% CI, 54%-80%), 32% (95% CI, 20%-44%), and 3% (95% CI, 1%-6%), respectively. Conservative treatment was effective in 28% (95% CI, 18%-37%) of patients and a single epidural blood patch was successful in 64% (95% CI, 56%-72%). Large epidural blood patches (>20 mL) had better success rates than small epidural blood patches (77% [95% CI, 63%-91%] and 66% [95% CI, 55%-77%], respectively).

Conclusions and Relevance

Spontaneous intracranial hypotension should not be excluded on the basis of a nonorthostatic headache, normal neuroimaging findings, or normal lumbar puncture opening pressure. Despite the heterogeneous nature of the studies available in the literature and the lack of controlled interventional studies, this systematic review offers a comprehensive and objective summary of the evidence on SIH that could be useful in guiding clinical practice and future research.

Compressive cervicothoracic pseudomeningocele as a rare manifestation of idiopathic intrathecal hypotension after past trauma: a review

PURPOSE

Spontaneous intracranial or intrathecal hypotension (SIH) is an underdiagnosed phenomenon predominantly presenting with low cerebrospinal fluid (CSF) pressure and postural headache in the setting of CSF leak. Extrathecal CSF collections causing compression of the spinal cord or nerve roots present an even rarer subset of this disease. We aim to describe this pathology in a comprehensive manner while illustrating with a case of our own.

METHODS

We present a literature review on spinal idiopathic pseudomeningoceles and their neurological implications illustrated with a case of an anterior compressive pseudomeningocele between C2 and D7. Further investigations through a myelography and myelo-CT were able to postulate a CSF leak through a discogenic osteophytic microspur at the level C5-C6.

RESULTS

Spinal manifestations are uncommon in cases of idiopathic or spontaneous CSF leak, occurring in about 6% of patients, but myelopathy and radiculopathy involving all spinal segments do occur. In contrast to the cranial complaints, the spinal manifestations usually are not positional and are caused by mass effect from an extradural CSF collection.

CONCLUSION

The utility of multiple imaging modalities such as dynamic myelography and the use of epidural blood patches and fibrin glue polymers should be explored, and surgery is an option if the symptoms persist despite other measures.

Intradural extraarachnoid sutureless technique combined with laminoplasty for indirect repair of ventral dural defects in spontaneous intracranial hypotension: technical note and case series

BACKGROUND

There is a significant variance in surgical treatment strategies of ventral cerebrospinal fluid (CSF) leaks causing spontaneous intracranial hypotension (SIH). Posterior approaches might represent a preferable alternative to the more invasive anterior and lateral routes, as long as the spinal cord is not exposed to harmful manipulation. The aim of this technical note is to report and illustrate a new surgical technique using an intradural extraarachnoid sutureless technique via laminoplasty for indirect repair of ventral CSF leaks causing intractable SIH symptoms.

METHODS

The surgical technique is described in a step by step fashion. Between May 2018 and May 2020, five patients with ventral spinal CSF leaks were operated on, utilizing this technique. All dural defects were located at the level of the thoracic spine. A retrospective review on demographic and radiological findings, symptoms, outcome, and follow-up was performed.

RESULTS

The intra- and postoperative course was uneventful in all patients with no surgery-related complications. Three patients recovered completely at discharge, while neurological symptoms significantly improved in two patients. A postoperative MRI of the spine was obtained for all patients, demonstrating regressive signs of CSF leak.

CONCLUSION

Based on the presented case series, this intradural extraarachnoid sutureless technique combined with laminoplasty seems to be a safe and effective option for indirect repair of ventral dural defects in SIH. In our opinion, it represents a valid alternative to traditional more aggressive approaches.

Monro-Kellie Hypothesis: Increase of Ventricular CSF Volume after Surgical Closure of a Spinal Dural Leak in Patients with Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE

CSF loss in spontaneous intracranial hypotension disrupts a well-regulated equilibrium. We aimed to evaluate the volume shift between intracranial compartments in patients with spontaneous intracranial hypotension before and after surgical closure of the underlying spinal dural breach.

MATERIALS AND METHODS

In total, 19 patients with spontaneous intracranial hypotension with a proved spinal CSF leak investigated at our institution between July 2014 and March 2017 (mean age, 41.8 years; 13 women) were included. Brain MR imaging-based volumetry at baseline and after surgery was performed with FreeSurfer. In addition, the spontaneous intracranial hypotension score, ranging from 0 to 9, with 0 indicating very low and 9 very high probability of spinal CSF loss, was calculated.

RESULTS

Total mean ventricular CSF volume significantly increased from baseline (15.3 mL) to posttreatment MR imaging (18.0 mL), resulting in a mean absolute and relative difference, +2.7 mL and +18.8% (95% CI, +1.2 to +3.9 mL; P < .001). The change was apparent in the early follow-up (mean, 4 days). No significant change in mean total brain volume was observed (1136.9 versus 1133.1 mL, P = .58). The mean spontaneous intracranial hypotension score decreased from 6.9  ± 1.5 at baseline to 2.9 ± 1.5 postoperatively.

CONCLUSIONS

Our study demonstrated a substantial increase in ventricular CSF volume in the early follow-up after surgical closure of the underlying spinal dural breach and may provide a causal link between spinal CSF loss and spontaneous intracranial hypotension. The concomitant decrease in the spontaneous intracranial hypotension score postoperatively implies the restoration of an equilibrium within the CSF compartment.

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”.

Spontaneous Intracranial Hypotension

BACKGROUND

Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. Its incidence is estimated at 5 per 100 000 persons per year.

METHODS

This review is based on a selective literature search in PubMed covering the years 2000-2019, as well as on the authors' personal experience.

RESULTS

The diagnostic and therapeutic methods discussed here are supported by level 4 evidence. SIH is caused by spinal leakage of cerebrospinal fluid (CSF) out of ventral dural tears or nerve root diverticula, or, in 2-5% of cases, through a fistula leading directly into the periradicular veins (CSF-venous fistula). In half of all patients, no CSF leak is demonstrable. A low CSF opening pressure on lumbar puncture is present in only one-third of patients; imaging studies are thus needed to confirm and localize a spinal CSF leak. Half of all patients in whom myelographic computed tomography (CT) reveals contrast medium reaching the epidural space have ventral dural tears, which tend to be located at upper thoracic spinal levels. Epidural blood patches applied under fluoroscopic or CT guidance can seal the CSF leak in 30-70% of patients, but 90% of patients with ventral dural tears will need operative closure. Some patients who have no visible epidural contrast medium on CT presumably do not have SIH, while others do, in fact, have a CSF leak from a diverticulum or a CSF-venous fistula and will need to have the site of the leak demonstrated with the aid of further studies, such as dynamic (subtraction) myelography in the lateral decubitus position.

CONCLUSION

The management of patients with SIH calls for complementary imaging studies to demonstrate the causative spinal CSF leak. Often, successful treatment requires surgical closure of the leak. In view of the sparse evidence available to date, controlled studies should be performed.

Spine MRI in Spontaneous Intracranial Hypotension for CSF Leak Detection: Nonsuperiority of Intrathecal Gadolinium to Heavily T2-Weighted Fat-Saturated Sequences

BACKGROUND AND PURPOSE

Spine MR imaging plays a pivotal role in the diagnostic work-up of spontaneous intracranial hypotension. The aim of this study was to compare the diagnostic accuracy of unenhanced spine MR imaging and intrathecal gadolinium-enhanced spine MR imaging for identification and localization of CSF leaks in patients with spontaneous intracranial hypotension.

MATERIALS AND METHODS

A retrospective study of patients with spontaneous intracranial hypotension examined from February 2013 to October 2017 was conducted. Their spine MR imaging was reviewed by 3 blinded readers for the presence of epidural CSF using 3 different sequences (T2WI, 3D T2WI fat-saturated, T1WI gadolinium). In patients with leaks, the presumed level of the leak was reported.

RESULTS

In total, 103 patients with spontaneous intracranial hypotension (63/103 [61%] women; mean age, 50 years) were evaluated. Seventy had a confirmed CSF leak (57/70 [81%] proved intraoperatively), and 33 showed no epidural CSF on multimodal imaging. Intrathecal gadolinium-enhanced spine MR imaging was nonsuperior to unenhanced spine MR imaging for the detection of epidural CSF (P = .24 and .97). All MR imaging sequences had a low accuracy for leak localization. In all patients, only 1 leakage point was present, albeit multiple suspicious lesions were reported in all sequences (mean, 5.0).

CONCLUSIONS

Intrathecal gadolinium-enhanced spine MR imaging does not improve the diagnostic accuracy for the detection of epidural CSF. Thus, it lacks a rationale to be included in the routine spontaneous intracranial hypotension work-up. Heavily T2-weighted images with fat saturation provide high accuracy for the detection of an epidural CSF collection. Low accuracy for leak localization is due to an extensive CSF collection spanning several vertebrae (false localizing sign), lack of temporal resolution, and a multiplicity of suspicious lesions, albeit only a single leakage site is present. Thus, dynamic examination is mandatory before targeted treatment is initiated.

Postoperative Cerebrospinal Fluid Leak After Lumbar Total Disc Replacement: A Diagnostic and Management Challenge

BACKGROUND

Lumbar total disc replacement is increasingly becoming a more common treatment for discogenic low back pain refractory to conservative measures. Nevertheless, several complications have been reported, including, among others, wound infection, vascular injury, retrograde ejaculation, postsympathectomy syndrome, ileus, and cerebrospinal fluid (CSF) leak. Although CSF leakage is rare, we discuss a case of CSF leakage and the diagnosis and management of CSF leakage after lumbar total disc replacement.

CASE DESCRIPTION

A 25-year-old man had presented with discogenic low back pain caused by degenerative disc disease of 9 years' duration. His symptoms were exacerbated by activity, worse with sitting, and relieved by ice baths. He developed a cerebrospinal fluid leak after L5-S1 lumbar total disc replacement.

CONCLUSIONS

Our patient ultimately required device removal, direct repair, and replacement with a different prosthesis to treat his CSF leak.