Spontaneous CSF Leaks

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.

Fluid-structure interaction study on the causes of mending material damage after sigmoid sinus wall reconstruction

BACKGROUND AND OBJECTIVE

Sigmoid Sinus (SS) Wall Reconstruction (SSWR) is the mainstream treatment for pulsatile tinnitus (PT), but it has a high risk of recurrence. The damage of mending material is the key cause of recurrence, and its hemodynamic mechanism is still unclear. The purpose of this study was to investigate the hemodynamic causes of mending material breakage.

METHODS

In this study, six patient-specific geometric models were reconstructed based on the data of the computed tomography angiography (CTA). The transient fluid-structure coupling method was performed to clarify the hemodynamic state of sigmoid sinus and the biomechanical state of the mending material. The distribution of stress and displacement and the flow pattern were calculated to evaluate the hemodynamic and biomechanics difference at the mending material area.

RESULTS

The area of blood flow impact in some patients (2/6) was consistent with the damaged location of the mending material. The average stress (6/6) and average displacement (6/6) of damaged mending material were higher than those of complete mending material. All (6/6) patients showed that the high-stress and high-displacement proportion of the DMM region was higher than that of the CMM region. Moreover, the average stress fluctuation (6/6) and average displacement (6/6) fluctuation degree of damaged mending material is larger than that of complete mending material.

CONCLUSIONS

The impact of blood and the uneven stress and displacement fluctuation of the mending material may be the causes of mending material damage. High stress and high displacement might be the key causes of the mending material damage.

Outcomes of Spontaneous Cerebrospinal Fluid Leak Repair With Concurrent Eustachian Tube Dysfunction

OBJECTIVE

To compare the presentation and outcomes of patients with and without obstructive eustachian tube dysfunction (oETD) undergoing repair of lateral skull base spontaneous cerebrospinal fluid (sCSF) leaks.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Adults with lateral skull base sCSF leaks who underwent repairs from January 1, 2011, to December 31, 2020, were collected.

MAIN OUTCOME MEASURE

Comparative statistics and effect sizes were used to compare clinical features, operative findings, and outcomes between groups.

RESULTS

Of 92 ears from 89 patients included, 51.1% (n = 47) had oETD. There were no differences in demographics between patients with and without oETD. Mean age was 60.7 ± 13.1 versus 58.5 ± 12.8 years ( d = -0.17 [-0.58 to 0.24]), mean body mass index was 33.8 ± 8.5 versus 36.0 ± 8.0 kg/m 2 ( d = 0.27 [-0.14 to 0.68]), and female sex preponderance was 59.6% (n = 28) versus 68.8% (n = 31; Φ = -0.09), respectively. There were no differences in the radiologic number, size, and locations of defects. Patients with oETD had less pneumatized mastoids than those without oETD ( p = 0.001; Φ = 0.43). Mean change from preoperative to postoperative air pure-tone average for those with and without oETD was -1.1 ± 12.6 versus 0.1 ± 17.2 dB ( d = 0.09 [-0.04 to 0.58]), respectively. Six ears (6.5%; three with and three without oETD) underwent revisions for rhinorrhea/otorrhea between 5 and 28 months postoperatively, during which four leaks were found, the two patients without leaks had oETD.

CONCLUSIONS

The presentation of sCSF leaks and outcomes of repairs in patients with oETD do not differ from those without oETD. Although postoperative otorrhea might represent an inflammatory or infectious process in patients with oETD, reexploration is warranted if patients do not improve with conservative treatment.

Cut-off value for β-trace protein (β-TP) as a rapid diagnostic of cerebrospinal fluid (CSF) leak detection

Objective

To find an adequate cut-off point for beta trace protein (β-TP) in nasal secretion (NS) and validate this diagnostic test with a large sample of patients. Likewise, we evaluated β-TP test efficacy to confirm the cerebrospinal fluid (CSF) leakage closure after treatment.

Methods

We performed a retrospective analysis with 207 samples from 162 patients with suspected CSF leakage received in the Hospital Universitario Virgen de la Arrixaca between 2010 and 2016. Twenty-five samples were included in the control group. Samples were obtained from NS through a swab to determine β-TP using a nephelometry-based assay. Sensitivity, specificity, and area under the curve (AUC) for β-TP in NS were assessed using the receiver operator characteristic (ROC) analysis.

Results

Using imaging techniques, the diagnosis of CSF leak was confirmed in 57 patients (35.19%), while 105 had a negative diagnosis (64.81%). Patients with CSF leakage had significantly higher β-TP values in NS (16.07 ± 16.94 mg/L, p < .001) than the control group (0.33 ± 0.12 mg/L) and patients without CSF leakage (0.61 ± 2.34 mg/L). Applying a 1 mg/L cut-off point resulted in 96.5% sensitivity and 97.1% specificity. Positive and negative predictive values (PPV and NPV) at this cut-off were 94.9% and 98.6%, respectively. Finally, this cut-off point yields a test efficacy for CSF leak diagnosis of 97% (95% CI 92.9-98.9).

Conclusion

Our study has established a 1 mg/L β-TP concentration in NS as a cut-off point for CSF leakage diagnosis with high sensibility and specificity. These results suggest that β-TP analysis could be useful to check CSF leak resolution.

Level of Evidence

4.

Combined surgical repair and venous sinus stenting for patients with skull base encephaloceles secondary to dural venous sinus stenosis

BACKGROUND

Chronically elevated intracranial pressure (ICP) seen in idiopathic intracranial hypertension (IIH) can cause the development of skull base encephaloceles and cerebrospinal fluid (CSF) leaks. Surgical repair and ventriculoperitoneal shunt (VPS) placement are mainstays of treatment. Venous sinus stenting (VSS) is a newly accepted treatment modality. The goal of this study was thus to determine if VSS can be used to treat symptoms and prevent recurrence after surgical encephalocele repair.

METHODS

Retrospective chart review of patients that had surgical repair of encephaloceles followed by VSS for symptomatic stenosis with elevated pressure gradient.

RESULTS

A total of 13 patients underwent a combined encephalocele repair and VSS. Seventy-two percent were female; 46% had headaches, 69% pulsatile tinnitus, and 92% CSF rhinorrhea or otorrhea. One had seizures. Mean lumbar opening pressure was 23.3 ± 2.6 cm H2O; the average sagittal-to-jugular pressure gradient was 12.7 ± 1.8 cmH2O and was elevated in all patients. Four patients had middle fossa craniotomy for repair of tegmen defect (one bilateral); one had a retrosigmoid craniotomy for repair of a sigmoid plate defect. Eight had an endoscopic endonasal repair for sphenoid or cribriform plate encephalocele. There were no VSS procedural complications or complications associated with dual antiplatelet therapy. One patient had meningitis after endoscopic repair that was treated with antibiotics. One patient had recurrence of both CSF leak and venous stenosis adjacent to the stent requiring repeat repair and VSS. There was no further recurrence.

CONCLUSION

In patients with dural sinus stenosis and encephaloceles requiring repair, VSS can be performed safely within weeks of surgery for relief of symptoms, resolution of underlying pathology, and prevention of CSF leak recurrence.

Elevated Body Mass Index Associated with Cerebrospinal Fluid Leak after Lateral Skull Base Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

To determine if body mass index (BMI) increases the risk of cerebrospinal fluid (CSF) leak after lateral skull base surgery.

DATA SOURCES

CINAHL, PubMed, and Scopus were searched from January 2010 to September 2022 for articles published in English.

STUDY SELECTION

Articles that reported BMI or obesity with and without CSF leaks after lateral skull base surgery were included.

DATA EXTRACTION

Two reviewers (F.G.D. and B.K.W.) independently performed study screening, data extraction, and risk of bias assessment.

DATA SYNTHESIS

A total of 11 studies and 9,132 patients met inclusion criteria. Meta-analysis of mean difference (MD), odds ratio (OR), proportions, and risk ratio (RR) were calculated using RevMan 5.4 and MedCalc 20.110. BMI for patients with CSF leak after lateral skull base surgery (29.39 kg/m2, 95% confidence interval [CI] = 27.75 to 31.04) was significantly greater than BMI for patients without CSF leak after lateral skull base surgery (27.09 kg/m2, 95% CI = 26.16 to 28.01) with an MD of 2.21 kg/m2 (95% CI = 1.09 to 3.34, p = 0.0001). The proportion of patients with BMI ≥ 30 kg/m2 that had a CSF leak was 12.7%, and the proportion of patients with BMI < 30 kg/m2 (control) that had a CSF leak was 7.9%. The OR for CSF leak after lateral skull base surgery in patients with BMI ≥ 30 kg/m2 was 1.94 (95% CI = 1.40 to 2.68, p < 0.0001), and the RR was 1.82 (95% CI = 1.36 to 2.43, p < 0.0001).

CONCLUSION

Elevated BMI increases the risk of CSF leak after lateral skull base surgery.

LEVEL OF EVIDENCE

IIa.

Spontaneous Cerebrospinal Fluid Rhinorrhea in a Patient With Breast Cancer

Despite the well documented increased risk of osteopenia in patients with breast cancer during chemotherapy and endocrine therapy, spontaneous cerebrospinal fluid rhinorrhea (CSFR) is still rare. The authors present a case of spontaneous CSFR that occurred during chemotherapy and endocrine therapy for breast cancer. The patient underwent a repair using myofascia and adipose tissue and was started on mannitol. There was no recurrence at 1-year follow-up. Therefore, clinicians should pay attention to the possibility of CSFR in patients with breast cancer, to avoid misdiagnosis.

Incidence of Postoperative CSF Leaks in Class III Obese Patients Undergoing Middle Cranial Fossa Approach for Spontaneous CSF Leak Repair

OBJECTIVE

To determine the safety and effectiveness of the middle cranial fossa (MCF) approach for spontaneous cerebrospinal fluid leak (sCSF-L) repair in class III obese patients. To also assess the need for prophylactic lumbar drain (LD) placement in this patient population.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary Academic Center.

PATIENTS

All patients older than 18 years undergoing sCSF-L repair with an MCF approach.

INTERVENTION

An MCF craniotomy for sCSF-L repair.

MAIN OUTCOME MEASURE

Rate of complications and postoperative leaks.

RESULTS

There were no perioperative complications in 78.9% (56/71) of cases. The surgical complication rate was 12.5% (2/16), 10% (2/20), and 22.2% (6/27) in class I, class II, and class III obese patients. There was no statistically significant difference in complications among these three groups. The most common postoperative complication was a persistent CSF leak in the acute postoperative period with an overall rate of 9.9% (7/71) with six of the seven patients requiring postoperative LD placement. The percentage of postoperative CSF leaks in nonobese, class I, class II, and class III patients were 25% (2/8), 12.5% (2/16), 0% (0/20), and 11.1% (3/27), respectively. There was no statistically significant difference in the rate of postoperative CSF leaks among the four groups (chi-square, p = 0.48). In all cases, the acute postoperative CSF leaks resolved in the long term and did not require further surgical repair.

CONCLUSIONS

We determine that MCF craniotomy repair for sCSF-Ls is safe in patients with class III obesity, and the incidence of postoperative CSF leaks did not vary among other obesity classes. We also find that prophylactic placement of LDs is not routinely needed in this population.

Spontaneous Cerebrospinal Fluid Rhinorrhea and Otorrhea: A Case Report and Literature Review

Spontaneous cerebrospinal fluid (CSF) leak is a condition that commonly presents with unilateral watery drainage from the nose or ear, tinnitus, and stuffy ears or hearing loss. Spontaneous CSF rhinorrhea and otorrhea together are rare. A 64-year-old woman presented at our department with complaints of clear watery rhinorrhea and hearing loss on the right side persisting for 10 months. Imaging and surgery were used to diagnose the condition. Through surgical treatment, she was eventually cured. Review of the literature has shown that patients with both nasal and aural CSF leaks are rare. When a patient presents with both unilateral watery drainage from both the nose and ear, a diagnosis of CSF rhinorrhea and otorrhea should be considered. This case report will benefit clinicians by providing more information to assist with diagnosing the disease.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Trends in Spontaneous Cerebrospinal Fluid Leak Repairs in the United States, 2009-2018

Background

Rates of spontaneous cerebrospinal fluid leak (sCSF) repairs have increased in recent decades in line with increases in obesity rates.

Objectives

To determine if the national rate of sCSF leak has continued to rise in recent years and to identify associated risk factors utilizing a comprehensive national database comprising most academic medical centers.

Methods

A retrospective review from 2009 to 2018 was performed using the Vizient Clinical Database (CDB) of 105 leading academic medical centers in the United States. Patients who underwent CSF leak repair in the CDB database using ICD-9 and ICD-10 diagnostic and procedure codes. Patients with epidural hematomas over the same time frame were used as a control. National rates of craniotomy for sCSF leak repair each quarter were assessed and sCSF leak patient characteristics (age, gender, obesity, hypertension, diabetes) were calculated.

Results

The rate of craniotomy for all sCSF leak repairs increased by 10.2% annually from 2009 to 2015 (P < 0.0001). There was no statistically significant change in the rate of epidural hematomas over the same period. The rate of lateral sCSF leak repair increased on average by 10.4% annually from 2009 (218 cases/year) to 2018 (457 cases/year) (P < 0.0001). A statistically significant increase was observed across all regions of the United States (P ≤ 0.005). sCSF leak patients had an average (standard deviation) age of 55.0 (13.2) years and 67.2% were female. Obesity was the only demographic factors that increased significantly over time. Likely due to comorbid factors, Black patients comprise a disproportionately large percentage of lateral sCSF leak repair patients.

Conclusions

The rate of craniotomy for spontaneous CSF leaks continues to rise by approximately 10% annually.

Approach to Management of Cerebrospinal Fluid Rhinorrhea: Institutional Based Protocol

The role of otolaryngologist in the management of CSF rhinorrhea is expanding. It is prudent to evaluate all cases of CSF leak, understand the etiological causes and formalize a working approach to management of such cases to yield better outcome. A retrospective descriptive study of 39 cases of proven CSF rhinorrhea treated at a tertiary care center between January 2014 to August 2019. The data retrieved were analyzed for age, gender, weight, etiology, recurrence of the disease, history of meningitis, nasal or neurosurgical intervention in past, imaging inform of CT and MR cisternography as and when required. This was aimed at understanding the various etiological types of CSF rhinorrhea and work out a management approach. The patients with skullbase tumors who presented with CSF Rhinorrhea were excluded from the study sample. There were 18 cases of spontaneous CSF rhinorrhea and 20 cases of traumatic CSF rhinorrhea. The mean BMI of spontaneous gp was 32.9 ± 2.46 kg/m2 while in traumatic group was 25.7 ± 2.94 kg/m2 and difference was statistically significant. None of the spontaneous CSF rhinorrhea cases showed features of raised ICP preoperatively either clinically or on imaging except empty sella in 14 of 18 cases. 6 of 18 cases of spontaneous category while 01 of 20 cases in traumatic had recurrence and the recurrence rate was significantly (p < 0.05) higher in spontaneous group. In traumatic group 7 were iatrogenic, 8 were occult traumatic and rest were acute traumatic. 4 of traumatic and 1 spontaneous group had history of meningitis and the incidence was 12.8% in our study group. Early identification and localization of CSF fistula is necessary to reduce morbidity and mortality associated with it. Risk of meningitis is high in CSF rhinorrhea especially in traumatic group. The etiology of CSF rhinorrhea has a bearing on the management and spontaneous CSF rhinorrhea has higher rate of recurrence.

Thinning of the Skull Base and Calvarial Thickness in Patients With Idiopathic Intracranial Hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a disorder characterized by elevated intracranial pressure without secondary causes on neuroimaging. IIH typically occurs in young, obese female patients and, when severe, can cause permanent and irreversible vision loss. The association between skull base thinning in patients with intracranial hypertension and obesity has been previously reported; however, no study has reported these findings in IIH. The goal of our study is to determine whether IIH is independently associated with skull base and calvarial thinning.

METHODS

A retrospective, matched case-control study was performed. Each patient diagnosed with IIH (case) was matched with a patient diagnosed with headache (control) by age, gender, and race. Patients were included if they underwent computed tomographic imaging of the head, maxillofacial, or orbits within 3 months of their diagnosis. Exclusion criteria were history of skull base or frontal bone pathology because of surgery or skull trauma, central nervous system infections, or incomplete radiologic data. Patient demographics, medical history, clinical examination, and skull base, calvarial, and zygoma thickness were recorded. Skull base thickness was measured by the height of the auditory canal in the coronal plane. Calvarial thickness was measured just anterior to the foramen rotundum in the coronal plane. Extracranial zygoma thickness was measured and used as an internal imaging control because the zygoma is not subject to intracranial forces.

RESULTS

One hundred twenty-six patients were included in the study, 63 cases and 63 controls. Each group comprised 61 female patients (97%), 24 (38%) Caucasian, 23 (37%) black, 1 (2%) Asian, and 15 (24%) others. The average age was 31.5 ± 8.7 years. Patients with IIH were more likely to be obese (n = 60, 95%) compared with the control patients (n = 23, 37%, P < 0.001). All patients with IIH underwent lumbar puncture (LP) with an average opening pressure (OP) of 40.5 ± 15.6 cm H2O, whereas only 13 (20%) controls underwent an LP with a mean OP of 19.5 ± 8.5 cm H2O. There was no statistical difference in mean visual acuity between the IIH and control groups (logMar 0.22 [20/30] ± 0.45 vs logMar 0.09 [20/25] ± 0.30, P = 0.093, respectively). Compared with the controls, patients with IIH were more likely to have headache (97% vs 74%, P = 0.001), pulsatile tinnitus (48% vs 7%, P < 0.001), horizontal binocular diplopia (24% vs 4%, P = 0.006), confrontational visual field deficit (23% vs 2%, P = 0.003), and papilledema (74% vs 0%, P < 0.001). Patients with IIH had thinner skull base and calvarium width compared with the controls (mean skull base thickness 4.17 ± 0.94 mm vs 5.05 ± 1.12 mm, P < 0.001 and mean calvarial width 1.50 ± 0.50 mm vs 1.71 ± 0.61 mm, P = 0.024). Zygoma thickness was similar in both groups (mean zygoma thickness 1.18 ± 0.30 mm in the IIH group vs 1.26 ± 0.35 mm in the control group, P = 0.105). In a subgroup analysis controlling for obesity (body mass index >30 kg/m2), there was no statistically significant difference in skull base, calvarial, or zygoma thickness between obese and nonobese patients.

CONCLUSIONS

Patients with IIH have thinner mean skull base and calvarial thickness compared with the controls. There was no difference in the mean extracranial zygoma thickness, which was the internal imaging control. Contrary to previous reports, we did not find an association between obesity and skull base or calvarial thinning. These findings suggest that IIH is associated with skull base and calvarial thinning.

Management of patients with medically intractable epilepsy and anterior temporal lobe encephaloceles

OBJECTIVE

Temporal lobe encephaloceles (TLENs) are a significant cause of medically refractory epilepsy, but there is little consensus regarding their workup and treatment. This study characterizes these lesions and their role in seizures and aims to standardize preoperative evaluation and surgical management.

METHODS

Patients with TLEN who had undergone resective epilepsy surgery from December 2015 to August 2020 at a single institution were included in the study. Medical records were reviewed for each patient to collect relevant seizure workup information including demographics, radiological findings, surgical data, and neuropsychological evaluation.

RESULTS

For patients who presented to the authors' program with suspected medically intractable temporal lobe epilepsy (219 patients), TLEN was considered to be the epileptogenic focus in 5.5%. Ten patients with TLEN had undergone resection and were included in this study. Concordance between ictal scalp electroencephalography (EEG) lateralization and TLEN was found in 9/10 patients (90%), and 4/10 patients (40%) had signs suggestive of idiopathic intracranial hypertension (IIH). Surgical outcome was reported in patients with at least 12 months of follow-up (9/10). Patients with scalp EEG findings concordant with the TLEN side had a good outcome (Engel class I: 7 patients, class II: 1 patient). One patient with discordant EEG findings had a bad outcome (Engel class III). No significant neuropsychological deficits were observed after the surgery.

CONCLUSIONS

TLENs are epileptogenic lesions that should be screened for in patients with medically refractory epilepsy who have signs of IIH and no other lesions on MRI. Restricted resection is safe and effective in patients with scalp EEG findings concordant with TLEN.

Imaging Characteristics of Sigmoid Sinus Wall Anomalies, Idiopathic Intracranial Hypertension, and Spontaneous CSF Leaks

OBJECTIVE

To assess the frequency of radiographic features of elevated intracranial pressure (ICP) in patients with sigmoid sinus wall anomalies (SSWA) and compare to those in idiopathic intracranial hypertension (IIH) and spontaneous CSF (sCSF) leaks.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care center.

PATIENTS

110 patients - 62 SSWAs, 19 IIH, 29 sCSF leaks.

MAIN OUTCOME MEASURES

Demographics, comorbidities and radiographic features by diagnosis.

RESULTS

Imaging findings indicative of elevated ICP were similar across all three groups, as were body mass index, hyperlipidemia and diabetes. On univariate analysis, sCSF leak patients were significantly older than SSWA (60 vs. 41 years, p < 0.001) and IIH (60 vs. 40 years, p < 0.001) patients. They had a greater prevalence of arachnoid granulations than SSWA (75.8% vs. 37.1%, p < 0.01) and tegmen dehiscence than both SSWA and IIH (93.1% vs. 75.8% vs. 57.8%, p = 0.01), though a lower prevalence of empty sella than SSWA (44.8% vs. 72.5%, p < 0.001). SSWAs were present in roughly 44.3% of IIH and sCSF leak patients, and IIH in roughly 15.8% of SSWA and sCSF leak patients. Age (OR = 1.1, p = 0.001), hypertension (OR = 8.3, p = 0.01) and empty sella (OR = 0.1, p = 0.01) were predictive of sCSF leaks compared to SSWAs on multivariate analysis.

CONCLUSIONS

Many radiographic and clinical features of elevated ICP are found at similar rates among patients with SSWA, IIH and sCSF leaks, suggesting a common underlying process. SSWAs seem to present earlier along this spectrum of phenotypes, while sCSF leaks present later. Differences in age, metabolic syndrome and ICP may influence a patient's clinical presentation.

Meningitis in the Setting of Frontoethmoidal and Temporal Meningoencephaloceles

This is a patient with multiple meningoencephaloceles which resulted in bacterial meningitis and subsequent status epilepticus. We identify impressive imaging findings demonstrating herniation of the meninges from nasal and bitemporal skull base defects possibly as a result of intracranial hypertension.

Endoscope-assisted microsurgical repair in trigeminal meningocele: case report

Trigeminal meningocele is a rare disease that results in rhinorrhea. Treatments with endoscopic approaches and open craniotomies have high recurrence rates, and controversy regarding the most effective surgical strategy for trigeminal meningocele is ongoing. The authors report a case of a 13-year-old female patient with a diagnosis of trigeminal meningocele determined after she presented with a history of intermittent headaches, suspected rhinorrhea, and recurrent meningitis. In addition to the conventional method of covering the efflux point of CSF and filling the inside of the meningocele with fascial tissues, the authors selectively closed the influx point of CSF from the prepontine cistern to the meningocele using an anterior transpetrosal approach. On the basis of the preoperative images, the authors hypothesized that the influx point of CSF could not be observed under the microscopic direct view and instead used a flexible endoscope. A check valve-like structure with one-way communication of CSF from the prepontine cistern into the cystic cavity was identified and was closed. At the time of this report, 36 months postoperatively, the patient had no indications of recurrence. Although cases of trigeminal meningoceles are infrequently encountered and require a tailored approach, the results in this case thus far indicate that the use of an endoscope and open craniotomy is an effective strategy for surgical treatment.

A Unique Subset: Idiopathic Intracranial Hypertension Presenting as Spontaneous CSF Leak of the Anterior Skull Base

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 H2O and elevated postoperatively to 30.8 cm H2O. 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.

Plasma Ablation-Assisted Endoscopic Endonasal Transpterygoid Approach to Sphenoid Lateral Recess Cerebrospinal Fluid Leaks: Technique and Outcome

BACKGROUND

Management of sphenoid lateral recess (SLR) cerebrospinal fluid (CSF) leaks present a challenge because of the location and requiring complete visualization of the defect for a successful repair. The endoscopic endonasal transpterygoid approach (EETPA) is considered the gold standard in addressing these defects. We lay out our experience in implementing this approach with plasma ablation.

METHODS

This is a case series of 11 diagnosed patients of SLR CSF leaks who underwent plasma ablation-assisted EETPA repair by a single surgeon between 2011 and 2020 at our institution. Outcomes in terms of surgical field grade on the Wormald 11-point grading scale, postoperative complications, healing on nasal endoscopy and imaging, and surgical success rate were assessed.

RESULTS

The etiology was spontaneous leak in 10 (90.9%) patients and secondary to temporal lobe abscess and/or meningitis in one (9.09%). Three (27%) patients were previously operated elsewhere by the transsphenoidal route, which we reoperated by this technique. As per Wormald grading, grade 1 field in 3 (27.27%), grade 2 in 6 (54.5%), and grade 3 in 2 cases (18.18%) were noted. Complications occurred in 3 patients (27%) in the form of dry eye (9%), meningitis (9%), and transient CSF rhinorrhea in the immediate postoperative period (9%). Repair sites were well healed on follow-up nasal endoscopy and imaging. The surgical success rate was 100%.

CONCLUSIONS

Plasma ablation-assisted EETPA allows for a uninostril approach to the SLR, easy accessibility, and better visualization with a bloodless field, which allows appropriate repair, thus minimizing complications and preventing recurrence.

Anterior temporal encephaloceles: Elusive, important, and rewarding to treat

OBJECTIVE

To investigate the etiology and longitudinal clinical, neuropsychological, psychosocial, and surgical outcome profile of patients with medication refractory epilepsy and temporal encephaloceles with a view to highlight diagnostic clues and management strategies.

METHODS

The comprehensive epilepsy program databases at two surgical epilepsy centers from January 2000 to October 2018 were reviewed for this observational study, to identify patients with encephaloceles causing temporal lobe epilepsy (TLE) and treated with surgical resection. Their clinical, radiological, neuropsychological, psychiatric, and surgical data were obtained. Body mass index (BMI) data were also reviewed due to possible correlation between idiopathic intracranial hypertension and encephaloceles.

RESULTS

Thirteen patients (eight female) were identified; only three were recognized on initial magnetic resonance imaging (MRI) report. Temporal encephaloceles were identified on the left in eight patients, on the right in three patients, and bilaterally in two patients. One patient had a strong family history of encephaloceles. The median BMI for patients with seizure onset ≤20 years of age was 22.4, whereas for patients with onset >20 years median BMI was 32.6 (P = .06). Five patients underwent a focal lesionectomy, three patients had limited temporal lobectomy, and five patients had standard anterior temporal lobectomy. Median postoperative follow-up was 5.5 years. All but one patient were free of disabling seizures. Nine of ten neuropsychologically tested patients had no discernable cognitive decline postoperatively. Postoperative psychosocial adjustment features were present in four patients.

SIGNIFICANCE

Genetic factors and a possible association with idiopathic intracranial hypertension (given female predominance and elevated BMI) may contribute to the causation of temporal lobe encephaloceles. It is notable that a targeted surgical approach in the management of patients with TLE associated with encephaloceles has an excellent long-term clinical and neuropsychological outcome. Subtle encephaloceles should be actively searched for in patients with drug-resistant TLE because they significantly change surgical strategy and prognostication.

An Expedited Intracranial Pressure Monitoring Protocol Following Spontaneous CSF Leak Repair

OBJECTIVE

Spontaneous cerebrospinal fluid (CSF) leaks represent a unique subset of skull base pathology and require distinctive management. Perioperative evaluation and management of intracranial hypertension are essential in preventing further erosion of the skull base and development of recurrent leak. The objective of this study is to evaluate the safety and utility of an expedited protocol for recording and managing intracranial hypertension following endoscopic repair of spontaneous CSF leaks.

METHODS

Prospectively collected data was reviewed in patients undergoing endoscopic repair of spontaneous CSF leaks between January 2017 and March 2020. A standard intracranial pressure monitoring protocol was compared to an expedited protocol (EP), and data regarding the two groups was compared for leak location, short-term success of skull base repair, complications, hospital length of stay, and cost-based analysis.

RESULTS

Fifty-five patients (standard protocol, n = 28 vs. EP, n = 27) were included in the study. Leak location was similar between cohorts, with the lateral recess being the most common locations in both groups (37.9% vs. 40.6%; P = .90). Postoperative complications (3.6% vs. 7.4%; P = .53) and ventriculoperitoneal shunt rate (32.1% vs. 22.2%; P = .41) were similar among cohorts. There was no difference in lumbar drain complications (0% vs. 7.4%; P = .14) or recurrent leak (7.1% vs. 0%; P = .16). Length of stay was shorter in the EP group [median(interquartile range): 3(1) vs. 2 (1); P < .01]. Total hospital charges were similar between groups (median (USD/$1,000): 83.57 ± 49.58 vs. 83.93 ± 46.11; P = .18).

CONCLUSION

An expedited monitoring protocol shortened hospital stay without increased risk of complications.

LEVEL OF EVIDENCE

III Laryngoscope, 131:E408-E412, 2021.

Cerebrospinal fluid fistula in a patient with chronic constipation related to an autonomic dysfunction and revealed by bacterial meningitis - A case report

Background:

Cerebrospinal fluid (CSF) fistula represents a rare neurosurgical entity that can be defined as a communication between the subarachnoid space and nasal fossa or less commonly the ear cavity. It can be spontaneous without an evident etiology or secondary following a skull base surgery or trauma. The early diagnosis of spontaneous forms remains a challenge as clinical signs (e.g., unilateral rhinorrhea) can be absent or neglected by patients and can result in meningitis.

Case Description:

Here, we report the case of a 31-year-old man with chronic constipation complicated by chronic intracranial hypertension, and resulting in rhinorrhea with bacterial meningitis. The etiological assessment of chronic constipation retained an autonomic dysfunction with sympathetic hyperactivity (e.g., pure autonomic failure) as an underlying cause. Beta-2 transferrin testing associated with cerebral magnetic resonance imaging and computed tomography scan confirmed the diagnosis and localization of the fistula at the cribriform plate. The patient underwent an endoscopic endonasal approach with a repair of fistula. He presented with recurrent rhinorrhea 17 months later which required a surgical revision along with CSF diversion with a ventriculoperitoneal shunt.

Conclusion:

Although rare, autonomic dysfunction can result in chronic constipation in young patients, with intermittent or permanent intracranial hypertension, leading to CSF leaks. The early identification and treatment of the underlying etiology may prevent severe complications and improve the management and outcome of CSF fistula patients.

Do Most Patients With a Spontaneous Cerebrospinal Fluid Leak Have Idiopathic Intracranial Hypertension?

BACKGROUND

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.

EVIDENCE ACQUISITION

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.

RESULTS

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.

CONCLUSIONS

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.

Intrathecal gadolinium-enhanced MR-cisternography for the detection of a petrous bone defect in a patient with spontaneous intraventricular pneumocephalus

Spontaneous otogenic pneumocephalus is a rare entity. We describe the case of a 55-year-old patient with intraventricular pneumocephalus associated with a bony defect at the level of the right petrous bone caused by otomastoiditis. She presented herself at the emergency department with a 1-month history of progressive balance problems, tinnitus and fullness in the right ear. Head-CT showed pneumocephalus secondary to chronic otomastoiditis with focal erosion of the petrous bone. Nasal fluid analysis tested positive on the presence of beta-transferrin. MRI before and after intrathecal gadolinium administration showed leakage of gadolinium into the right mastoid air cells. The dural defect was closed by an artificial graft. Post-operatively, gait problems, rhinorrhea and tinnitus resolved, but of mild-to-moderate headache persisted at a 3-month outpatient evaluation. This article shows that CT is the imperative for the diagnosis of pneumocephalus and to detect the underlying cause. When there is doubt about the fistula location, MR-cisternography with gadolinium can be a valuable tool to detect or confirm the fistulous site.

Chemotherapy associated dural sinus thrombosis presenting as a cerebrospinal fluid leak

Despite the well documented increased risk of thrombosis in patients with cancer and during chemotherapy, cerebral venous sinus thrombosis (CVT) remains a rare entity. We present a rare case of cerebrospinal fluid (CSF) rhinorrhoea secondary to a left transverse sinus thrombus which occurred 2 years previously during chemotherapy for breast cancer. The patient underwent a three-layer repair using Neuro-Patch, septal cartilage and middle turbinate pedicle flap and was started on acetazolamide. There was no recurrence at 1-year follow-up. Raised intracranial pressure secondary to cerebral venous occlusion can erode the base of skull and predispose to CSF leaks. Despite the theoretical risk, there have been no cases reported where CSF leaks have occurred following chemotherapy induced CVT. We describe the first case and discuss pathophysiology and management.

Chronic Aspiration Pneumonitis Caused by Spontaneous Cerebrospinal Fluid Fistulae of the Skull Base

OBJECTIVES/HYPOTHESIS

Spontaneous cerebrospinal fluid (CSF) leaks of the skull base are associated with obesity, multiparity, and elevated intracranial pressure. Although spontaneous CSF leaks often present with rhinorrhea, they can be an underdiagnosed cause of chronic aspiration pneumonitis, a complication that has not been previously reported in detail.

STUDY DESIGN

Retrospective case series.

METHODS

The authors retrospectively reviewed all patients undergoing surgical repair of CSF fistulae at the University of Southern California between 2011 and 2018 to identify those presenting with pulmonary symptoms including dyspnea, aspiration, chronic cough, and shortness of breath caused by chronic noniatrogenic CSF pneumonitis.

RESULTS

Symptomatic chronic pneumonitis was evident in six of 20 patients with spontaneous CSF rhinorrhea. Five women (mean body mass index = 36) had CSF leaks arising from the fovea ethmoidalis (n = 4) and lateral sphenoid region (n = 1). One man had a middle fossa floor dehiscence draining through the eustachian tube. All patients had bilateral ground-glass opacities in their lungs on computed tomography imaging that were attributed to spontaneous CSF fistulae arising from noniatrogenic skull base defects, and one patient underwent a biopsy of a lung lesion at another hospital showing chronic bronchiolitis and adjacent peribronchiolar metaplasia. Five patients underwent endoscopic endonasal repair using an autologous fascial graft and pedicled nasoseptal flap, and one underwent craniotomy for repair. All patients underwent successful repair with no complications or evidence of recurrence. Upon repair of the spontaneous CSF leaks, both pneumonitis symptoms and ground-glass opacities on imaging resolved in all six cases.

CONCLUSIONS

Skull base CSF fistulae should be considered as a reversible cause of chronic pneumonitis that is not alleviated or worsens with standard treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:462-466, 2021.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Middle Cranial Fossa Repair of Temporal Bone Spontaneous CSF Leaks With Hydroxyapatite Bone Cement

OBJECTIVES

To determine the safety and effectiveness of the middle cranial fossa (MCF) approach in repairing spontaneous cerebrospinal fluid (sCSF) leaks.

STUDY DESIGN

Retrospective cohort study.

METHODS

Patient with sCSF leaks repaired by MCF approach between January 1, 2014 and August 31, 2019 were included. Demographic information, clinical and surgical findings, and postoperative outcomes were recorded.

RESULTS

The cohort (n = 45) included 24 tegmen repairs by multilayer reconstruction using hydroxyapatite cement and 21 cases of multilayer repair without hydroxyapatite cement. Ten MCF repairs were performed on patients ≥65 years old. Twenty (53%) ears had multiple tegmen defects (range, 1-9 tegmen defects) and 78% of patients had ≥1 encephaloceles. All sCSF leaks were resolved with one surgical intervention. There were no major intracranial complications. Transient expressive aphasia occurred in 2 patients. Medical complications occurred in four patients. There were no short-term postoperative CSF leaks with bone cement reconstruction and two postoperative leaks without bone cement. One resolved with lumbar drain (LD) and the other resolved without treatment. The average (SD) length of stay (LOS) with bone cement was shorter than in patients without bone cement (2.54 [0.83] days vs. 3.52 [1.99] days, P < .05). There have been no long-term CSF leak recurrences with an average (SD) follow-up of 13.5 (12.9) months (range 0.25-46 months).

CONCLUSIONS

MCF approach for sCSF repairs demonstrate efficacious outcomes, particularly with tegmen reconstruction using hydroxyapatite cement. The approach exhibited no serious adverse events and few complications requiring intervention. Therefore, MCF is a safe and effective approach to resolve sCSF leaks.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:624-632, 2021.

Successful Treatment of Spontaneous Cerebrospinal Fluid Rhinorrhea With Endoscopic Third Ventriculostomy and Lumboperitoneal Shunt: A Case Report

Spontaneous cerebrospinal fluid (CSF) rhinorrhea represents an important clinical entity that is being observed with increasing prevalence, ranging from 14 to 55%. Spontaneous CSF rhinorrhea is associated with elevated intracranial pressure (ICP), which is rarely stopped without surgical intervention. Endoscopic endonasal repair is typically warranted for CSF rhinorrhea. However, the recurrence rate of CSF leaks after the endoscopic endonasal repair of skull base defects due to ICP is usually high. We describe a 25-year-old man without a history of head injury, tumor, or obesity. The onset of his symptoms occurred in 1 week in the form of a persistent clear left nostril rhinorrhea. Computed tomography (CT) and magnetic resonance images (MRI) showed signs of CSF in the left sphenoidal sinus, meningocele in the left frontal sinus, empty sella, hydrocephalus, and Chiari I malformation (CIM). Cine-MRI revealed the flow of CSF was obstructed at the aqueduct and the outlet of the fourth ventricle. Endoscopic third ventriculostomy (ETV) was performed for the patient with obstructive hydrocephalus. Post-operative CSF pressure measurement demonstrated elevated ICP. The patient still had case of CSF rhinorrhea, and subsequently underwent lumboperitoneal shunt (LPS) for treatment of ICP. The patient showed a prompt resolution of CSF leak. Ten months later, the patient showed a significant improvement in terms of his herniated tonsil and cessation of CSF rhinorrhea.

Delayed Diagnosis and Treatment of Cerebrospinal Fluid Leakage in Current Practice

As delayed diagnosis and treatment of cerebrospinal fluid (CSF) leakage are common in current practice, this study was performed to determine associated factors and discuss appropriate strategies to deal with these problems. A retrospective analysis of all cases of CSF leakage in our hospital from 2007 to 2018, including 41 patients with CSF rhinorrhea and 5 with CSF otorhinorrhea, was performed. Symptoms, associated diseases, misdiagnoses, history of skull base repair surgical, previous medical costs, and number of hospital visits before visiting our institution were reviewed. The diagnoses, surgical reconstruction methods, and prognoses of the patients were analyzed. In 18 patients, CSF leakage was spontaneous, in 14 the cause was trauma, and in the remaining 14 the origin was iatrogenic. Twelve patients had been misdiagnosed with allergic rhinitis, rhinosinusitis, or otitis media. Twelve cases had intracranial infection and 14 suffered airway infection. Six had undergone unsuccessful craniotomy, endonasal endoscopic surgery, or ear surgery for treatment of CSF leakage before visiting our institute. This resulted in an average of 5.13 ± 1.32 referrals and medical costs of up to 20,795.7 ± 4553.80 RMB. The success rate was 97.83% after repairing CSF fistulae in our hospital. The septal floor flap (SFF) method (based on ethmoidal arteries) to treat CSF rhinorrhea showed a success rate of 100% in 12 patients. Therefore, early localization, clinical diagnosis, and appropriate repair surgery can avoid the occurrence of delayed events. Pedicled flaps, including SFF, are recommended to manage challenging CSF rhinorrhea.

Epidural Blood Patch as a Diagnostic and Therapeutic Intervention in Spontaneous Intracranial Hypotension: A Novel Approach to Management

OBJECTIVE

Spontaneous intracranial hypotension (SIH) remains a diagnostic and therapeutic challenge. Nonspecific clinical features and a reluctance to treat without confirmatory imaging evidence undermine management. Investigations are often insensitive and expensive, with many patients continuing to an epidural blood patch (EBP) despite negative results. Current diagnostic standards are based on a literature base skewed toward difficult-to-treat cases at specialty centers. This study aims to develop a robust diagnostic and treatment algorithm in real-life clinical practice by 1) investigating the prognostic utility of symptoms of SIH and results of associated investigation from which a scoring system is derived and 2) analyzing the role of EBP as a diagnostic and treatment tool.

METHODS

This is a retrospective study of 86 patients fulfilling clinical criteria for SIH and undergoing EBP, with follow-up ranging from 1 month to 15 years, using patient medical records and an online questionnaire.

RESULTS

Although specific and prognostically significant, magnetic resonance imaging of the brain, magnetic resonance imaging of the spine, and symptom-based scoring systems were too insensitive to be of practical use. Most patients with positive and sustained responses to EBP did not meet current criteria for diagnosis. The 72-hour response to the first EBP was found to be highly specific and sensitive in the diagnosis of SIH in our cohort.

CONCLUSIONS

This study supports the utility of EBP as a safe, accessible, and accurate diagnostic and therapeutic tool. We propose a simple treatment algorithm that facilitates diagnosis, treatment, and prediction of long-term outcomes in this challenging condition.

Tegmen attenuation in patients with idiopathic intracranial hypertension is progressive

OBJECTIVES

To prove that temporal bone tegmen attenuation in patients with idiopathic intracranial hypertension (IIH) is progressive.

STUDY DESIGN

Retrospective blind study at a tertiary academic medical center.

METHODS

Enrolled were medical records of patients with IIH that included at least two sequential computed tomography (CT) scans. The vertical distances between the floor of the middle fossa to the superior and lateral semicircular canals (SSC and LSC, respectively), to the scutum and minimal squama thickness were measured. The same measurements were made in scans of control subjects. The impact of demographics and metabolic variables including opening lumbar puncture (LP) pressure were evaluated.

RESULTS

Twenty medical records were enrolled. Median age at diagnosis was 21 years; 16 were females. The median body mass index (BMI) was 32 kg/m² . Initial LP pressure was 195 mm cerebrospinal fluid (CSF). The median time interval between CT scans was 58 months. A median attenuation of 0.35 mm and 0.25 mm over the right and left LSC and of 0.5 mm and 0.3 mm over the right and left scutum, was found, respectively. The thicknesses of the SSC and squama remained stable. No attenuation was present in controls. The opening pressure on initial LP (median 195 mm CSF), was positively correlated with the degree of tegmen attenuation, but the age at diagnosis and BMI were not.

CONCLUSIONS

Tegmen attenuation may be progressive in patients with idiopathic increased intracranial pressure and correlated with the opening pressure on LP. Tegmen defects and CSF leak should be looked for in these patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 2020.

Endoscopic repair of cribriform plate cerebrospinal fluid leaks: An easy and reproducible technique sparing the middle turbinate

OBJECTIVE

The purpose of this study was to evaluate the outcomes of patients with cribriform cerebrospinal fluid leaks undergoing endoscopic repair with an easy and reproducible middle turbinate-sparing technique.

MATERIAL AND METHODS

Date was obtained by retrospective chart review and includes a description of the technique with technical pearls and contraindications to the approach.

RESULTS

We report 17 patients who underwent repair of cribriform cerebrospinal fluid leaks with a middle turbinate-sparing technique with 100% success rate at a mean follow up of 38 months. One patient complained of hyposmia. There were no other complications.

CONCLUSIONS

The endoscopic middle turbinate-sparing approach to repair cribriform cerebrospinal fluid leaks using a free mucosal graft is easy, effective, and reproducible.

Endoscopic Endonasal Repair of Spontaneous Cerebrospinal Fluid Leaks Using Multilayer Composite Graft and Vascularized Pedicled Nasoseptal Flap Technique

Background

Endoscopic repair of cerebrospinal fluid (CSF) fistulas is a fundamental practice in anterior skull base surgery due to high success rates and low morbidity profile. However, spontaneous CSF (sCSF) leaks have the highest recurrence rate compared to other etiologies. The most effective management is undetermined due to variations in graft materials and limited evidence.

Objective

We present the largest study of a standardized endoscopic repair technique for sCSF leaks.

Methods

Single-institution retrospective review of patients who underwent endoscopic sCSF leak repair between October 2011 and January 2018. All patients underwent repair using a temporary lumbar drain, intrathecal fluorescein, and multilayer reconstruction using bilayered fascia lata autograft and vascularized nasoseptal flap.

Results

Twenty patients (100% female, mean age: 53.2 years) with 25 separate sCSF leak sites were included. Obesity was present in 15 of 20 patients (mean body mass index [BMI] = 35.3). No patients had previous sinus surgery. Locations of skull base defects included: cribriform plate (44%), ethmoid (32%), lateral sphenoid (12%), and planum sphenoidale (12%). The mean follow-up was 22.8 months and 92% of the leak sites (23/25) were successfully repaired primarily. There were no neurological complications or cases of meningitis. Two patients (mean BMI = 52) with persistent postoperative CSF leaks and elevated intracranial pressure were successfully managed with ventriculoperitoneal shunt placement. BMI was associated with likelihood of repair failure (P = .003).

Conclusions

At our institution, endoscopic repair of sCSF leaks using a composite autograft of fascia and a nasoseptal flap demonstrates high success rates. Elevated BMI was a statistically significant risk factor for revision.

Prevalence of Obstructive Sleep Apnea (OSA) in Spontaneous Cerebrospinal Fluid (CSF) Leaks: A Prospective Cohort Study

OBJECTIVE

To determine the prevalence of obstructive sleep apnea (OSA) in a prospective cohort of patients with spontaneous CSF (sCSF) leaks of the temporal bone.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Consecutive sCSF leak patients (21) over a 3-year period. Four patients presented with a history of OSA and 17 patients were prospectively offered polysomnogram (PSG) testing during the initial clinic encounter.

INTERVENTION

Level I PSG.

MAIN OUTCOME MEASURES

Patient characteristics (age, sex, body mass index), apnea hypopnea index (AHI), presence of snoring, and presence of hypoxia (oxygen saturation <88% for >5 min). OSA was defined as mild (AHI ≥5 and <15/h), moderate (AHI ≥15 and <30/h), and severe (AHI ≥30/h).

RESULTS

The prevalence of OSA in sCSF leak patients is 83.3%. PSG studies were performed on 18 of the 21 patients. There were 15 women and 6 men with an average age (standard deviation) of 56.3 (11.2) years and an average body mass index of 35.3 (7.7) kg/m. Objectively, the AHI ranged from mild to severe (range = 5.7-92, median = 19.8). Snoring was present in 61% of patients and hypoxia was present in 39% of patients. sCSF leak patients with OSA were significantly older than sCSF leak patients without OSA (56.7 [8.3] versus 42.7 [14.5] yr, p = 0.03).

CONCLUSIONS

OSA is highly prevalent among patients with sCSF leaks. All patients with sCSF leaks should undergo formal PSG testing. Future studies are needed to determine the role of OSA in the development of sCSF leaks.

Association of Obstructive Sleep Apnea With Calvarial and Skull Base Thinning

Importance

Spontaneous cerebrospinal fluid leaks (sCSF-L) of the temporal bone are associated with obesity, calvarial thinning, and obstructive sleep apnea (OSA), and the incidence has doubled in the past decade. It is currently unknown if OSA is independently associated with skull thinning.

Objective

To determine if patients with OSA have thinner skulls than patients without OSA.

Design, Setting, and Participants

A retrospective cohort study of patients who underwent a level 1 polysomnogram (PSG) and also had high-resolution computed tomographic (CT) imaging of the head from January 2010 to March 2017 at Indiana University was carried out. Patients with moderate to severe OSA (apnea-hypopnea index [AHI]≥25/h) and without OSA (AHI<5/h) were matched for age and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared).

Interventions

Measurement of calvarial thickness, extracranial zygoma thickness, skull base height and tegmen dehiscence (>4 mm) when blinded to OSA status.

Main Outcomes and Measures

Primary outcomes were calvarial, skull base, and zygoma thickness differences between patients with OSA vs those without OSA.

Results

A total of 22 933 patients had a PSG and 1012 also had head CT imaging. Of the 1012 patients with both PSG and CT, the mean (SD) age was 50.8 (16.2) years and 624 (61.7%) were women. Those patients with moderate to severe OSA (56) and without OSA (58) were matched for mean (SD) age (50.3 [6.5] vs 49.8 [6.1] years]) and BMI (37.4 [8.1] vs 38.6 [6.8]). Patients with OSA had thinner mean (SD) calvaria (2.73 [0.67] vs 2.47 [0.52] mm; difference, -0.26 mm; 95% CI, -0.49 to -0.04; Cohen d, 0.44) and thinner skull bases (5.03 [1.40] vs 4.32 [1.28] mm; difference, -0.71; 95% CI, -1.23 to -0.19; Cohen d, 0.53). The mean (SD) extracranial zygoma thickness was the same (4.92 [0.87] vs 4.84 [0.84] mm; difference, -0.07 mm; 95% CI, -0.39 to 0.24). The tegmen mastoideum was dehiscent in nearly twice as many patients with OSA as those without (37% vs 20%; difference, 17%; 95% CI, 0.4-32).

Conclusions and Relevance

Obstructive sleep apnea was independently associated with intracranial bone (calvaria and skull base) thinning and not with extracranial (zygoma) thinning. These findings support a possible role of OSA in the pathophysiologic development of sCSF-L.

Reconstruction of the skull base in spontaneous rhinoliquorrhea

Objective/Hypothesis: Spontaneous rhinoliquorrhea often occurs due to defects of the skull base. It is often misinterpreted as rhinitis and is surgically the most difficult rhinoliquorrhea entity to close. Methods: We conducted a retrospective chart analysis of patients that were diagnosed with spontaneous rhinoliquorrhea at the University Hospital Bonn between 2001 and 2017. Results: Overall, twelve patients were included in this study. On average, the time between occurrence of nasal discharge and diagnoses of rhinoliquorrhea was 123 days. In ten patients, the localization of the skull base defect could be localized by computed tomography or MRI cisternography. Ten patients underwent surgery, of which 9 remained recurrence free. One patient underwent revision surgery and from thereon was recurrence free. Conclusion: Spontaneous rhinoliquorrhea still remains a diagnostic and therapeutic challenge. Whenever persistent watery nasal discharge appears in a patient, rhinoliquorrhea must be considered. Endoscopic surgical reconstruction of the skull base is the therapeutic gold standard and should be attempted as soon as the diagnosis is secured.

Delayed presentation of morning glory disc anomaly and transsphenoidal encephalocele: A management dilemma

Background Morning glory disc anomaly (MGDA) is a rare developmental abnormality of the optic disc that is associated with many other neurological and vascular conditions. Most cases are diagnosed in childhood. Case Report We report a 57-year-old woman who presented to the ophthalmology department for assessment of long-standing poor vision in the left eye and exotropia. Examination showed a left MGDA and bitemporal hemianopsia. These findings prompted magnetic resonance imaging, revealing a transsphenoidal basal meningoencephalocele with herniation of the optic chiasm and inferior hypothalamus into the dural sac. Due to the eloquence of the neurovascular structures it contained, a decision was made not to reduce the meningoencephalocele. Instead, a ventriculoperitoneal shunt was placed. The patient's ophthalmologic examination remained stable over the following year. Conclusion While rare, MGDA can be first diagnosed in late adulthood and a thorough evaluation should be completed to assess for midline cranial defects, vascular abnormalities, and other associated abnormalities. Patients presenting late in life with basal encephalocele, herniation of the optic chiasm, and bitemporal hemianopsia present a management dilemma. In this case, a ventriculoperitoneal shunt was placed with the intention of lowering intracranial pressure to prevent further herniation and reduce the risk of cerebrospinal fluid leak.

Idiopathic intracranial hypertension presenting as bilateral spontaneous lateral intrasphenoidal and transethmoidal meningoceles: a case report and review of the literature

Background

Basal meningoceles are rare herniations of the meninges that tend to present unilaterally with cerebrospinal fluid rhinorrhea. Growing evidence suggests that intracranial hypertension contributes considerably to the formation of spontaneous basal meningoceles.

Case presentation

A 50-year-old man of Middle East ethnicity presented with a 16-week history of cerebrospinal fluid rhinorrhea, short-term memory loss, and slight decline in cognitive function. We present a case of bilateral spontaneous meningoceles with bone defects in the left lateral sphenoid sinus and right anterior cribriform plate, as well as with a remodeled sella. A neuronavigation-assisted expanded endoscopic endonasal surgery was performed to resect the meningoceles. Postoperative imaging demonstrated complete resolution of the bilateral meningoceles.

Conclusions

This case reports the first bilateral basal spontaneous meningoceles in the literature. Furthermore, based on this case’s imaging results and the literature reviewed, elevated intracranial pressure may be a determining factor behind the development of spontaneous meningoceles.

The Effect of lumbar drains on spontaneous cerebrospinal fluid leak repair

Objectives:

To address the factors affecting recurrence after endoscopic surgical repairs of spontaneous cerebrospinal fluid leak, specifically the influence of using lumbar drains.

Methods:

This study involved a retrospective data analysis, including a chart review of all spontaneous cerebrospinal fluid (CSF) leak cases who underwent endoscopic anterior skull base repair from 2012-2017 in King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia.

Results:

Thirteen patients with spontaneous CSF leaks were identified and evaluated. The majority were females (92.3%) with an average body mass index of 34.9. All patients underwent endoscopic repair with intra-operative lumbar drain placement. Patients continued having post-operative lumbar drain for an average of 6.4 days. Four patients (30.8%) developed recurrence; however, only one of those had a documented high opening pressure.

Conclusion:

Spontaneous CSF leak repairs are at a higher failure risk and may have an underlying pathology involving CSF circulation. The use of lumbar drains and intracranial pressure lowering agents are controversial and seems to be reserved only for high risk patients; however, the higher risk of recurrence in this group may be better managed by proper pre-operative evaluation and selective, patient-specific management protocols.

Spontaneous nasal cerebrospinal fluid leaks: management of 24 patients over 11 years

PURPOSE

Most cases of non-traumatic nasal cerebrospinal fluid (CSF) leaks occur spontaneously without any obvious reason. Severe and life-threatening complications are possible consequences. Endoscopic repair is considered the gold standard; however, diagnosis and therapy of these CSF leaks stay challenging.

METHODS

In this retrospective analysis, patients who presented with spontaneous nasal CSF leaks from 2006 to 2017 were included. Symptoms, diagnostics, localization of the skull base defect, surgical method, outcome, and postoperative treatment were recorded.

RESULTS

Twenty four patients were included. 8 patients presented with symptoms of meningitis. The skull base defects were most commonly located in the anterior ethmoid roof-especially in the cribriform plate-and in the lateral part of the sphenoid sinus. 21 patients had a BMI above 25. In only 13 cases the defect could be detected preoperatively via computed tomography or additional magnetic resonance imaging. In all patients intraoperative visualization of the CSF leak was possible using intrathecal application of sodium-fluorescein. Endoscopic repair was the initial surgical method for all patients and proved to be successful in 80% of the cases. In most cases surgical revision was performed endoscopically; however, in two patients an open transpterygoidal approach was necessary.

CONCLUSIONS

Spontaneous nasal CSF leaks often initially present with symptomatic meningitis. Imaging does not always clearly identify the skull base defect. Common localizations are the anterior ethmoid roof and the lateral sphenoid sinus. Obesity seems to be a predisposing factor. In most cases, endoscopic repair with low morbidity is possible; however, an individualized approach is necessary.

Endoscopic Repairs of Sinonasal Cerebrospinal Leaks: Outcome and Prognostic Factors

OBJECTIVE

The aim of this study was to review the management of sinonasal cerebrospinal fluid (CSF) leaks and outcome of endoscopic repairs and to provide experience regarding leaks at the lateral wall of sphenoid sinus and the posterior wall of frontal sinus.

METHODS

Patients who underwent endoscopic repairs of CSF leaks were reviewed. Characteristics of different etiologies were compared, and prognostic factors were analyzed.

RESULTS

The study included 144 patients with 150 CSF leaks, in which spontaneous leaks account for 55%. Patients with traumatic leaks were significantly younger than those with spontaneous leaks (P = 0.012), and most traumatic leaks occurred in men (P < 0.001). The computed tomography scan showed an overall accuracy of 86.7%. For 17 leaks at the lateral wall of sphenoid sinus, transnasal (29%), transethmoid (24%), and transpterygoid (47%) approaches were used, with a success rate of 75%. For 11 defects at the posterior wall of the frontal sinus, 2 were managed by draf III surgery, and 3 by trephination-assisted procedure successfully. Success rate for primary repair was 95.6%, reaching 100% after a second repairing. Six leaks failed to be repaired included 4 spontaneous leaks, and 3 occurred at the lateral wall of the sphenoid sinus, 4 occurred in patients with elevated body mass index (BMI), 4 had evidence of raised intracranial pressure (ICP).

CONCLUSION

Repair of leaks at lateral sphenoid sinus and posterior frontal sinus could achieve favorable results via selected endoscopic approaches. The failure of repair was associated with inaccessible leak sites, spontaneous leaks, raised ICP, and elevated BMI.

Cerebrospinal fluid rhinorrhea and otorrhea: A multimodality imaging approach

Cerebrospinal fluid (CSF) leaks are extracranial egress of CSF into the adjacent paranasal sinus or tympanomastoid cavity due to an osteodural defect involving skull base. It can be due to a multitude of causes including accidental or iatrogenic trauma, congenital malformations and spontaneous leaks. Accurate localization of the site of the leak, underlying causes and appropriate therapy is necessary to avoid associated complications. In this paper relevant anatomy, clinical diagnosis, imaging modalities and associated findings are discussed along with a brief mention about management.