Clinical Presentation and Epidemiology of Spontaneous Cerebrospinal Fluid Leaks.

Idiopathic intracranial hypertension (IIH) is increasingly recognized as a cause of spontaneous cerebrospinal fluid (CSF) leak in the otolarnygological and neurosurgical literature. The diagnosis of IIH in patients with spontaneous CSF leaks typically is made a few weeks after surgical repair of the leak when symptoms and signs of elevated intracranial pressure (ICP) appear. Case reports and literature review. Two young obese women developed spontaneous CSF rhinorrhea related to an empty sella in one and a cribriform plate encephalocele in the other. Both patients underwent surgical repair of the CSF leak. A few weeks later, they developed chronic headaches and bilateral papilledema. Lumbar punctures showed elevated CSF opening pressures with normal CSF contents, with temporary improvement of headaches. A man with a 3-year history of untreated IIH developed spontaneous CSF rhinorrhea. He experienced improvement of his headaches and papilledema after a CSF shunting procedure, and the rhinorrhea resolved after endoscopic repair of the leak. These cases and the literature review confirm a definite association between IIH and spontaneous CSF leak based on: 1) similar demographics; 2) increased ICP in some patients with spontaneous CSF leak after leak repair; 3) higher rate of leak recurrence in patients with raised ICP; 4) patients with intracranial hypertension secondary to tumors may develop CSF leak, confirming that raised ICP from other causes than IIH can cause CSF leak. CSF leak occasionally may keep IIH patients symptom-free; however, classic symptoms and signs of intracranial hypertension may develop after a CSF leak is repaired, exposing these patients to a high risk of recurrence of the leak unless an ICP-lowering intervention is performed.

To review the most recent literature on the relationship of spontaneous cerebrospinal fluid (CSF) leak with idiopathic intracranial hypertension (IIH) and considerations in management of these conditions. A link has been proposed between spontaneous CSF leak and IIH based on similar demographics, radiologic, and clinical findings in these patients, and on a plausible mechanism of skull base erosion in the setting of high CSF pressure over time. IIH patients with CSF leak may not present with classic IIH signs and symptoms as the leak can alleviate excess pressure; however, they may develop these after a leak is repaired. There may also be a higher risk of leak recurrence if intracranial hypertension is not treated postoperatively. A growing body of evidence supports an association between IIH and spontaneous CSF leak. However, this relationship is still not fully elucidated, and there is no current agreement on how to incorporate screening, management, or counseling guidelines for CSF leak into the care of IIH patients. There are also no specific guidelines for evaluation/management of IIH in patients with spontaneous CSF leak. Further interdisciplinary research is needed to explore this connection and to establish screening, evaluation, and management guidelines.

15 - Pathophysiology of spontaneous cerebrospinal fluid leaks and their relationship with idiopathic intracranial hypertension

Increased Intracranial Pressure in Spontaneous CSF Leak Patients Is Not Associated with Papilledema

Spontaneous nasal cerebrospinal fluid (CSF) leaks represent a distinct clinical entity that presents important diagnostic and therapeutic challenges. Recognition of the proper demographic group and presenting symptoms, as well as the radiologic features of this disease process, are integral to making the appropriate diagnosis. In addition, this patient group requires special perioperative and intraoperative considerations for suitable management. Current literature echoes previously published success rates for endoscopic repair of CSF leaks at or above 90%. Success rates for closure of spontaneous CSF leaks, however, continue to be the lowest in comparison with other CSF leak etiologies. The increased failure rate for spontaneous CSF leak repair is likely due to the increased intracranial pressure present in this patient group. Patients with spontaneous CSF leaks are increasingly being recognized as belonging to a group inclusive of patients with benign intracranial hypertension and empty sella syndrome. In this review, we highlight the demographic characteristics, clinical presentation and radiologic findings that distinguish spontaneous nasal CSF leak patients from those with other CSF leak etiologies. We also discuss perioperative measures advocated for patients with spontaneous nasal CSF leaks that may aid in the success of their surgical repair.

The association between spontaneous skull base cerebrospinal fluid (CSF) leaks and idiopathic intracranial hypertension (IIH) has been suggested, but its significance remains unclear. To estimate the prevalence of IIH in spontaneous skull base CSF leak patients. Systematic collection of demographics, neuro-ophthalmic and magnetic resonance imaging evaluation of spontaneous skull base CSF leak patients seen pre- and post-leak repair in one neuro-ophthalmology service. Patients with preexisting IIH were diagnosed with definite IIH if adequate documentation was provided; otherwise, they were categorized with presumed IIH. Classic radiographic signs of intracranial hypertension and bilateral transverse venous sinus stenosis were recorded. Thirty six patients were included (age [interquartile range]: 50 [45;54] years; 94% women; body mass index: 36.8 [30.5;39.9] kg/m2), among whom six (16.7%, [95% confidence interval, CI]: [6.4;32.8]) had a preexisting diagnosis of definite or presumed IIH. Of the remaining 30 patients, four (13.3%, 95%CI: [3.8;30.7]) had optic nerve head changes suggesting previously undiagnosed IIH, while one was newly diagnosed with definite IIH at initial consultation. One out of 29 patients with normal findings of the optic nerve head at presentation developed new onset papilledema following surgery (3.4%, 95%CI: [0.1;17.8]) and was ultimately diagnosed with definite IIH. Overall, the prevalence of definite IIH was 19.4% (95%CI: [8.2;36.0]). Striking demographic overlap exists between IIH patients and those with spontaneous CSF leak. Definite IIH was present in approximately 20% of our patients. However, its true prevalence is likely higher than identified by using classic criteria. We therefore hypothesize that an active CSF leak serves as an auto-diversion for CSF, thereby "treating" the intracranial hypertension and eliminating characteristic signs and symptoms at initial presentation.

Increased intracranial pressure in spontaneous CSF leak patients is not associated with papilledema.

Spontaneous cerebrospinal fluid (CSF) leaks are a morbid condition associated with operative intervention for treatment. Understanding associations are key to diagnosis, treatment, and possible early detection. To determine the clinical association and odds of having obstructive sleep apnea (OSA) and spontaneous CSF leaks. A comprehensive search of the literature was conducted using PubMed (MEDLINE), Cochrane Library, and relevant article bibliographies. Systematic review and meta-analysis of studies from 2005 to 2015 investigating spontaneous CSF leaks in patients with OSA. The CSF leaks were considered spontaneous when they occurred in the absence of trauma, surgery, infection, and neoplasm. Included studies provided the number of patients diagnosed as having OSA and spontaneous CSF leaks. Two independent investigators reviewed all studies for inclusion. The numbers of patients with OSA were systematically extracted from each study. Studies that compared the prevalence of OSA with spontaneous CSF leaks against their control cohort were pooled in the meta-analysis using a random-effects model. To determine whether there was increased incidence of OSA in patients with spontaneous CSF leaks. This hypothesis was formulated prior to data collection. The search criteria yielded 384 abstracts, and 6 clinical studies involving OSA and CSF leaks met the inclusion and exclusion criteria. They were all retrospective in nature and included 3 comparative (case-control) studies, 2 case series, and 1 case report. The cumulative reported prevalence of having OSA and spontaneous CSF leaks is 16.9% (232 of 1376 patients). Three of the studies were eligible for the meta-analysis. The odds of having OSA with a spontaneous CSF leak were 4.73 times more likely than in control cohorts (95% CI, 1.56-14.31; P = .006; I² = 35%). In a subgroup analysis of studies including nonspontaneous CSF leaks as their control cohort, the odds of having OSA with a spontaneous CSF leak were 2.85 times more likely than OSA with a nonspontaneous CSF leak (95% CI, 1.22-6.63; P = .02; I² = 0%). There was a notable difference in the age, BMI, or patients with hypertension in the comparative studies. The association between OSA and spontaneous CSF leaks as demonstrated by retrospective studies is confounded by heterogeneous patient characteristics. Large prospective controlled studies using polysomnography and elevated intracranial pressure measurements are required to further evaluate the relationship between OSA and spontaneous CSF leaks.

Spontaneous cerebrospinal fluid (CSF) leaks represent a clinical entity in which CSF rhinorrhea occurs in the absence of any inciting event. Spontaneous CSF leaks are associated with elevated intracranial pressure (ICP) or have underlying idiopathic intracranial hypertension (IIH). We report a cohort of patients who have undergone nasal endoscopic repair for spontaneous CSF leaks. We review our perioperative complications and the effectiveness of the nasal endoscopic approach to repair spontaneous CSF leaks. Also, we examine the evidence correlating spontaneous CSF leaks and IIH and the role of decreasing ICP in the treatment of nasal spontaneous CSF leaks. A retrospective analysis of patients with nasal spontaneous cerebrospinal fluid leaks was performed. Data on the nature of presentation, patient body mass index, defect location and size, ICP, clinical follow-up, and complications were collected. Thirty-five patients had nasal spontaneous cerebrospinal fluid leaks with evidence of IIH's symptoms. The most common sites were the cribriform plate, the ethmoid roof, and sphenoid lateral pterygoid recess. All patients underwent endonasal endoscopic surgery to repair the defect. Postoperatively, all patients underwent lumbar drainage and acetazolamide therapy. Nasal spontaneous cerebrospinal fluid leaks represent a surgical challenge because of their high recurrence rates. The most important factor for obtaining a successful repair in these patients is reducing their intracranial pressure through nutritional, medical, or surgical means.

Primary, spontaneous cerebrospinal fluid (CSF) leaks secondary to defects in the clivus are exceedingly rare. Additionally, primary, spontaneous CSF leaks are typically present in obese women with idiopathic intracranial hypertension (IIH). In the present study, we report the first case of a primary, spontaneous CSF leak in the inferior-posterior wall of the clivus in an atypical patient with a BMI of 18.9 kg/m2 without IIH. Accurate diagnoses of CSF leaks are imperative in the context of preventing meningitis, and delays in diagnosis and treatment are associated with worse outcomes. Improved characterization of rare, spontaneous CSF leaks may prove beneficial in correctly diagnosing affected patients.

Introduction Spontaneous cerebrospinal fluid (CSF) leaks represent a unique clinical presentation of idiopathic intracranial hypertension (IIH), lacking classical features of IIH, including severe headaches, papilledema, and markedly elevated opening pressures. Methods Following a single-institution retrospective review of patients undergoing spontaneous CSF leak repair, we performed a literature review of spontaneous CSF leak in patients previously undiagnosed with IIH, querying PubMed. Results Our literature review yielded 26 studies, comprising 716 patients. Average age was 51 years with 80.8% female predominance, and average body mass index was 35.5. Presenting symptoms included headaches (32.5%), visual disturbances (4.2%), and a history of meningitis (15.3%). Papilledema occurred in 14.1%. An empty sella was present in 77.7%. Slit ventricles and venous sinus stenosis comprised 7.7 and 31.8%, respectively. CSF leak most commonly originated from the sphenoid sinus (41.1%), cribriform plate (25.4%), and ethmoid skull base (20.4%). Preoperative opening pressures were normal at 22.4 cm H 2 O and elevated postoperatively to 30.8 cm H 2 O. 19.1% of patients underwent shunt placement. CSF leak recurred after repair in 10.5% of patients, 78.6% involving the initial site. A total of 85.7% of these patients were managed with repeat surgical intervention, and 23.2% underwent a shunting procedure. Conclusion Spontaneous CSF leaks represent a distinct variant of IIH, distinguished by decreased prevalence of headaches, lack of visual deficits, and normal opening pressures. Delayed measurement of opening pressure after leak repair may be helpful to diagnose IIH. Permanent CSF diversion may be indicated in patients exhibiting significantly elevated opening pressures postoperatively, refractory symptoms of IIH, or recurrent CSF leak.

The association between cerebrospinal fluid (CSF) leaks at the skull base and raised intracranial pressure (ICP) has been reported since the 1960s. It has been suggested that spontaneous CSF leaks might represent a variant of idiopathic intracranial hypertension (IIH). We review the evidence regarding the association between spontaneous CSF leaks and IIH, and the role of ICP in the pathophysiology of nontraumatic skull base defects. We also discuss the management of ICP in the setting of CSF leaks and IIH. References were identified by searches of PubMed from 1955 to September 2018 with the terms "idiopathic intracranial hypertension" and "cerebrospinal fluid leak." Additional references were identified using the terms "pseudotumor cerebri," "intracranial hypertension," "benign intracranial hypertension," and by hand search of relevant articles. A CSF leak entails the egress of CSF from the subarachnoid spaces of the skull base into the surrounding cavitary structures. Striking overlaps exist regarding demographic, clinical, and radiological characteristics between IIH patients and those with spontaneous CSF leaks, suggesting that some (if not most) of these patients have IIH. However, determining whether a patient with spontaneous CSF leak may have IIH may be difficult, as signs and symptoms of raised ICP may be obviated by the leak. The pathophysiology is unknown but might stem from progressive erosion of the thin bone of the skull base by persistent pulsatile high CSF pressure. Currently, there is no consensus regarding the management of ICP after spontaneous CSF leak repair when IIH is suspected. IIH is becoming more widely recognized as a cause of spontaneous CSF leaks, but the causal relationship remains poorly characterized. Systematic evaluation and follow-up of patients with spontaneous CSF leaks by neuro-ophthalmologists will help clarify the relation between IIH and spontaneous CSF leaks.

Aspiration pneumonitis (AP) secondary to cerebrospinal fluid (CSF) leak is underestimated and rarely discussed. This study aimed to evaluate the association between AP and CSF leaks. Clinical and surgical characteristics of CSF leak patients with and without AP between January 2010 and December 2022 were included and compared. This study included 159 patients, 16 with CSF otorrhea and 143 with CSF rhinorrhea. Among them, 40 (25.2%) had AP. Bilateral pneumonitis was identified in 32 cases, of which 11 showed severe pneumonitis in the right upper lung lobe. Twenty-one (52.5%) asymptomatic and 19 (47.5%) symptomatic cases were documented. The major clinical manifestations included cough (n=19, 47.5%) and expectoration (n=9, 22.5%). The prevalence of pneumonitis was significantly higher in the spontaneous group than in the traumatic group. High-flow CSF leak was associated with AP (42.5%vs. 16.8%, p=0.001). No significant differences were identified in defect locations between patients with and without AP. Patients with pneumonitis had a higher prevalence of meningitis (32.5%vs. 12.6%, p=0.003). Multiple logistic regression results revealed that meningitis, spontaneous and high-flow CSF leaks are independent factors for AP occurrence. Both the CSF leak and pulmonary complications resolved following successful surgical repair. AP secondary to CSF leaks is frequently underdiagnosed, with a higher incidence identified in spontaneous cases. The occurrence of AP was associated with high-flow CSF leak. A pneumonitis rate of 25.2% in cerebrospinal fluid (CSF) leak patients was reported for the first time. A higher prevalence of aspiration pneumonitis was identified in spontaneous CSF leak. Meningitis, spontaneous and high-flow CSF leaks are independent factors for aspiration pneumonitis occurrence.

Elevated intracranial pressure can cause skull base defects and a spontaneous cerebrospinal fluid (CSF) leak. Venous sinus stenting (VSS) has emerged as a promising treatment option for patients with a CSF leak in the setting of idiopathic intracranial hypertension (IIH). There is a lack of literature on symptomatology and quality of life (QOL) after VSS for IIH patients with a CSF leak. This study explores the effects of VSS on symptoms and QOL in IIH patients with a CSF leak. This is a retrospective study on patients who have IIH complicated by a CSF leak and underwent VSS. A QOL questionnaire was developed from the migraine disability assessment test and the PROMIS-PI was given to patients included in this study. A total of 10 patients were included in this study. Nine patients underwent endoscopic closure of CSF prior to stent placement and one patient was treated with VSS only. There was no evidence of CSF leak recurrence in this population following VSS. Headaches improved in 5/8, tinnitus in 5/6, and visual disturbance in 4/5 patients. Diamox was discontinued in seven out of eight patients after VSS. There was an improvement in headache-specific questions ( p = 0.0140) and overall QOL ( p = 0.0061) on the QOL questionnaire. This preliminary study demonstrates that VSS is effective in alleviating many symptoms in IIH patients with a CSF leak, especially headaches. Diamox may be able to be discontinued in many patients following VSS. No CSF leak recurrence was noted in this patient population.

Spontaneous spinal cerebrospinal fluid (CSF) leaks are rare (5 per 100,000 per year). Treatment generally consists of conservative therapy or interventional therapy with epidural blood patching. Surgical treatment is conducted rarely, usually in cases when conservative or interventional treatment has failed. The aim of our case series was to assess the clinical outcome after surgery. Our clinical database was reviewed for patients with spontaneous spinal CSF leaks who underwent surgical exploration between 2010 and 2013. Etiology, symptoms, preoperative imaging, type of required surgical method, intraoperative findings, and clinical outcome were reported. We identified five patients with a mean age of 62years with spontaneous spinal CSF leaks who were treated surgically. Two patients received surgery after failure of interventional treatment. The origin of the CSF leak could be identified intraoperatively in three cases. Surgical technique in all cases consisted of an interlaminar fenestration or hemilaminectomy and a complete foraminotomy to explore the thecal sack and the exiting nerve roots and identify the CSF leak. After surgery, the preoperative symptoms improved in all patients. In one case, there was a relapse after 4weeks. Preoperative identification of a CSF leak with MRI was positive in only one case. In all other cases, a post-myelography CT had to be performed. In all cases, the preoperative symptoms improved after surgery. Surgical treatment is an effective treatment of spontaneous cerebrospinal fluid leaks in cases of refractory symptoms after failed conservative or interventional treatment.