Imaging of skull-base cephalocoeles and cerebrospinal fluid leaks

Pediatric Congenital Anterior Skull Base Encephaloceles and Surgical Management: A Comparative Review of 22 Patients Treated With Transnasally, Transcranially, or Combined Approach With a Review of the Literature

BACKGROUND AND OBJECTIVES

Anterior basal encephaloceles are considered a rare entity and are often associated with midline cerebral abnormalities. Those with a large skull base defect and herniation of brain parenchyma in the neonate or young infant present unique challenges for surgical management.

METHODS

We analyzed the neurosurgical administrative and operative databases between 1986 and 2022 to determine clinical presentation, operative approach, and outcome of basal encephaloceles.

RESULTS

Over the 36-year period, 27 pediatric anterior basal encephaloceles were managed, of which 22 had full documentation and images allowing comprehensive review. Mean age at presentation was 5 years (SD 4.94). The majority were transethmoidal encephaloceles (59%), followed by the transsphenoidal-sphenoethmoidal type (32%). Overall, 91% were managed surgically by a transcranial, endoscopic, or combined approach. Four children required subsequent procedures, predominantly for persistent cerebrospinal fluid leak. No significant differences in proportion of patients requiring interval/revision surgery after initial conservative, endoscopic endonasal, or transcranial surgery was identified. Neither age at surgery nor size of the defect on computed tomography scan was associated with the need for revision surgery. Size of cranial defect was significantly smaller in the endoscopic group (P = .01). There was a historic tendency for younger children with larger defects to have a transcranial approach. With the addition of endoscopic skull base expertise, smaller defects in older children were more recently treated endoscopically.

CONCLUSION

Basal encephaloceles are rare and complex lesions and are optimally managed within a skull base multidisciplinary team able to provide multiple approaches. Large skull base defects with brain parenchymal involvement often require a transcranial or combined transcranial-endoscopic approach.

Special Considerations in Pediatric Endoscopic Skull Base Surgery

Originally pioneered in adults, endoscopic endonasal approaches for skull base pathology are being increasingly applied as a minimally invasive alternative for young children. Intrinsic anatomic differences between these patient populations have sparked discussions on the feasibility, safety, and efficacy of these techniques in pediatric patients. This work aims to serve as a primer for clinicians engaged in the rapidly evolving field of pediatric endoscopic skull base surgery. A succinct overview of relevant embryology, sinonasal anatomy, and diagnostic workup is presented to emphasize key differences and unique technical considerations. Additional discussions regarding select skull base lesions, reconstructive paradigms, potential surgical complications, and postoperative care are also highlighted in the setting of multidisciplinary teams.

Superinfected and Ruptured Occipital Meningocele: Case Report

Meningocele is a rare congenital malformation of the central nervous system resulting from a herniation of the meninges containing cerebrospinal fluid through a bony defect in the skull. It is part of neural tube closure anomalies. The overall incidence of meningocele is 0.8 to 3 per 10 000 live births; it varies based on geographical location and race, with a predominance of occipital localization. Among diagnostic methods, computed tomography (CT) and magnetic resonance imaging (MRI) remain crucial examinations. Prenatal diagnosis of this malformation primarily relies on ultrasound and screening through maternal serum alpha-fetoprotein (AFP) levels. They typically manifest very early at birth with a highly suggestive radioclinical presentation. Surgical treatment usually allows for a definitive cure. Superinfection and rupture of the meningocele are exceptional, resulting from delayed diagnosis and management. In several developed countries, prevention through genetic counseling and the intake of folic acid during the periconceptional period, along with accurate prenatal diagnosis and the legalization of therapeutic abortion, has led to a decrease in the prevalence of meningoceles. In less developed countries, where there is a delay in diagnosis in exceptional cases, superinfection and rupture may occur. We present the case of an 8-month-old infant with a complicated occipital meningocele with superinfection and rupture.

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.

MRI features to aid the identification of lateral temporal bone cephaloceles

OBJECTIVES

To evaluate ancillary MRI features which may aid the identification of lateral temporal bone cephaloceles (LTBCs).

METHODS

A retrospective cohort study analysed patients with MRI evidence of surgically confirmed spontaneous LTBCs as defined by intracranial contents traversing the tegmen tympani or mastoideum. Cases were identified from radiology and surgical databases. Two observers analysed three-dimensional T 2W temporal bone and whole brain imaging according to a priori criteria by consensus, with emphasis on the relationship of any adjacent cerebrospinal fluid (CSF) cleft to the defect. The contents, location, and clinical features of the LTBCs were recorded.

RESULTS

Eighteen patients (11 female, 7 male; mean age 59.3 years, age range 42-86 years) with 20 surgically confirmed spontaneous LTBCs (2 bilateral;16 unilateral) were evaluated. A temporal lobe sulcus or other CSF cleft extending to or traversing the defect was identified in 19/20 (95%) cases. Isointense CSF tympanomastoid signal was present in 41.2% cases, whilst superior semi-circular canal dehiscence was found in 40% of cephaloceles. At least two MRI features of idiopathic intracranial hypertension were seen in 38.9% patients. Cephaloceles were most commonly centred on the tegmen tympani (55%). Meningoencephaloceles were present in 95% cases.

CONCLUSION

A temporal lobe sulcus or CSF cleft extending to or traversing the defect may aid the identification of LTBCs. Isointense CSF tympanomastoid signal, superior semi-circular canal dehiscence and MRI features of idiopathic intracranial hypertension are only present in under half of LTBCs.

ADVANCES IN KNOWLEDGE

The study details novel ancillary MRI features of LTBCs which may aid their identification.

A Rare Case of Cerebrospinal Fluid Rhinorrhea from Canal of Stenberg

Background: A spontaneous cerebrospinal leak from Sternberg's canal with meningoencephalocele is a very rare clinical entity. Endoscopic repair of the defect is challenging and crucial in identifying the defect. The aim of this case report is to highlight the presence and management with endoscopic surgery in repairing Sternberg canal. Case: 40-year-old woman presents with spontaneous CSF rhinorrhea with no predisposing factors. CT imaging and MRI showed osteodural defect in the lateral recess of sphenoid with meningoencephalocoele lateral to the foramen rotundum. Endoscopic transethmoidal - transphenoidal - transpterygoid approach was used to repair the defect, and patient is well post-operative with least complication from the intervention surgery. Conclusion: Endoscopic approach proved to be the best and safest method in localizing the defect and closure of the leak. Angled scopes and image guided system were used to identify the precise location of the leak.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03347-z.

The Need for Emphasis on Intracranial Hypertension Management in Spontaneous Skull Base Meningoencephaloceles

OBJECTIVE

To provide an analysis of patients with spontaneous skull base meningoencephaloceles (MECs) to determine whether definitive surgical treatment requires management of elevated intracranial pressure (ICP).

METHODS

Data of 10 subjects with spontaneous MECs were collected and retrospectively evaluated. Measurement of ICP, prior interventions, treatment with acetazolamide, and characteristics of long-term elevated ICP, among others, were analyzed. Our own indications for cerebrospinal fluid (CSF) diversion and use of postoperative external lumbar drain were analyzed as well.

RESULTS

The sphenoid region was the most common location of MECs. CSF leak was diagnosed in all subjects. The most common graphical signs of elevated ICP were empty sella and arachnoid pits, both of which were present in 90% of cases. Lumbar puncture with opening pressure measurement was performed in 7 patients. Ventriculoperitoneal shunt insertion was indicated in 4 cases before skull base repair and in 2 cases after skull base repair. Two postoperative CSF leaks were managed with external lumbar drain and subsequent shunt installation.

CONCLUSIONS

Spontaneous MECs are often associated with CSF leak. ICP assessment should be a standard of care to ensure successful operative repair of MECs. Insertion of a CSF diversion device must be considered where direct or indirect signs of intracranial hypertension are present.

Symptoms Underestimate the Presence of Obstructive Sleep Apnea in Patients with Spontaneous Cerebrospinal Fluid Leaks of the Temporal Bone

OBJECTIVE

To determine the severity of symptoms and degree of obstructive sleep apnea (OSA) in patients with spontaneous cerebrospinal fluid (sCSF) leaks of the temporal bone given the known association between sCSF leaks and OSA.

STUDY DESIGN

Retrospective case review.

SETTING

Ambulatory clinics in tertiary referral centers.

PATIENTS

Polysomnogram testing in 34 consecutive patients who had been diagnosed with sCSF leaks of the temporal bone was examined. Diagnosis of sCSF leak was defined as biochemically confirmed CSF from middle ear fluid with no other obvious source.

INTERVENTION

Diagnostic.

MAIN OUTCOMES MEASURES

Patient characteristics (age, sex, body mass index, Epworth Sleepiness Scale score, presence of hypoxia, overnight change in blood pressure, and apnea hypopnea index [AHI]) were recorded. Diagnosis of OSA was defined as mild when AHI ≥5 and <15/h, moderate when AHI ≥15 and <30/h, and severe when AHI ≥30/h.

RESULTS

Of the 34 patients, 28 (82%) had a confirmed diagnosis of OSA. There was a male predisposition in those with OSA, and 17 of 28 (61%) were male. A majority were overweight, and the mean body mass index was 30.1 (SD, 4.8; range, 23.2-40) kg/m2. The mean severity of OSA was moderate, and the mean AHI was 28.7 (SD, 21.9; range, 5.4-92.8). Of the 28 patients, 13 with OSA (46%) had Epworth Sleepiness Scale scores higher than 8, suggesting that many were asymptomatic for excessive daytime sleepiness at the time of presentation.

CONCLUSION

OSA is highly prevalent among patients with sCSF leaks of the temporal bone. Patients with sCSF leaks irrespective of symptoms of OSA should undergo formal polysomnogram testing.

Imaging of Congenital Craniofacial Anomalies and Syndromes

Craniofacial malformation is one of the most commonly encountered birth defects in the prenatal and postnatal periods. Higher-resolution and 3D antenatal ultrasonography and multidetector computed tomographic scan with 3D reformatted images have improved the definition of the soft tissue and bone structures of the craniofacial anatomy and its malformations. Early diagnosis of these conditions is important to make the clinical decisions and more so in understanding the possibility of malformation recurring in the next pregnancy, which is one of the major concerns for the parents and the treating physicians.

Expansion of the Foramen Ovale in Patients With Cerebrospinal Fluid Leak or Encephalocele

OBJECTIVE

Spontaneous cerebrospinal fluid (CSF) leaks are associated with elevated intracranial pressure and idiopathic intracranial hypertension (IIH). Skull base erosion and widening of the foramen ovale have been reported in patients with IIH. This study sought to investigate changes in the size of the foramen ovale and foramen spinosum in patients with IIH, spontaneous CSF leak, and encephalocele.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic medical center.

PATIENTS

Adult patients treated from 2014 to 2018 with computed tomographic imaging of the head and who were diagnosed with IIH, encephalocele, or CSF leak.

INTERVENTION

Two blinded observers measured the long and short axes of the foramen ovale and foramen spinosum on axial computed tomographic images. Measurements were used to calculate the approximate elliptical cross-sectional area of the foramina.

MAIN OUTCOME MEASURES

Length, width, and area of the foramen ovale and foramen spinosum.

RESULTS

A total of 264 patients were identified meeting the inclusion criteria and were placed into three groups. There were 170 patients with IIH, 48 with spontaneous CSF leak or encephalocele (CSF/E group), and 46 with traumatic or iatrogenic CSF leak (control group). Mean foramen ovale short axis (4.85 ± 1.00 mm) and cross-sectional area (30.17 ± 9.25 mm2) in the CSF/E group were significantly increased compared with measurements in patients with IIH or the control groups. Foramen ovale size was positively correlated with age in the CSF/E group. No significant difference in foramen spinosum size was found.

CONCLUSION

Skull base defect resulting in spontaneous CSF leak or encephalocele is associated with enlargement of the foramen ovale on axial computed tomography.

Anatomy of the Calvaria and Skull Base

A thorough understanding of the skull anatomy is of key importance to radiologists as well as specialist physicians and surgeons. We describe the anatomy of the neurocranium comprising calvaria (the skull vault) and the skull base and discuss the most common and clinically relevant anatomic variants.

Predisposing conditions for bacterial meningitis in children: what radiologists need to know

A variety of underlying diseases can predispose infants and children to bacterial meningitis (BM). For the diagnosis, treatment, and prevention of its recurrence, radiologists should be familiar with its predisposing conditions so that they can suggest the appropriate imaging approach. Predisposing conditions of BM can be broadly classified into two categories: infection spread from the adjacent tissue to the cerebrospinal fluid (CSF) space and immunodeficiency. Diseases in the former category are further divided according to regardless of whether there is a structural defect between the CSF space and the adjacent tissue. When a structural defect is suspected in a patient with BM, computed tomography (CT) of the head and magnetic resonance (MR) imaging are first-line imaging examinations. Radionuclide cisternography should be implemented as a second-line step to identify the CSF leak site. In patients with suspected parameningeal infection without any structural defect, such as sinusitis or otitis media/mastoiditis, CT or MR images can identify not only the disease itself but also the associated intracranial complications. The purpose of this article is to discuss the diagnostic approach and imaging findings associated with the variety of conditions predisposing patients to recurrent BM, focusing on the role of radiology in their management.

Special MRI Techniques to Suss out Spontaneous Cerebrospinal Fluid Leaks

Anterior skull base cerebrospinal fluid (CSF) fistulas result from skull base osteodural defects, allowing subarachnoid space CSF to escape into pneumatized cavities such as the paranasal sinuses and nasal fossa. Precise localization, characterization, and effective treatment of CSF leaks is essential to prevent meningitis, treatment failure, or recurrence. Advances in magnetic resonance imaging have improved radiologists' ability to localize and characterize anterior skull base CSF fistulas. This article reviews new imaging techniques enabling diagnostic location of CSF fistulas, with an emphasis on magnetic resonance imaging-based techniques.

Characteristics of Pediatric Recurrent Bacterial Meningitis in Beijing Children's Hospital, 2006-2019

BACKGROUND

Few data on recurrent bacterial meningitis (RBM) in children are available. Here, we estimated the frequency of RBM in children and investigated the predisposing conditions, etiology, and clinical characteristics of RBM in children.

METHODS

Cases of RBM in the Beijing Children's Hospital medical record database between January 2006 and December 2019 were collected.

RESULTS

In total, 1905 children with bacterial meningitis (BM) were documented in the Beijing Children's Hospital medical record database. A total of 43 patients had RBM. The rate of RBM in children was 2.3% (43/1905). Forty (93.0%) patients had predisposing conditions, including 15 (34.9%) cases of inner ear malformations, 5 (11.6%) cases of dermal sinus tracts, 9 (20.9%) cases of head injury, 5 (11.6%) cases of congenital cranial meningocele, 3 (7.0%) cases of congenital skull base defects, 3 (7.0%) cases of immunodeficiency, and other 3 (7.0%) cases of unknown reason. Among all the 121 BM episodes, a total of 64 episodes were etiologically confirmed BM and the other 57 episodes were probable BM. Streptococcus pneumoniae (n = 52) was accounted for 81.3% of confirmed BM episodes. Thirty-four of the 37 patients with congenital or acquired anatomical defects were available to follow up after surgeries, and all of them had no BM after surgeries. Three patients with antibody deficiencies got intravenous immunoglobulin therapy and they did not suffer BM anymore.

CONCLUSIONS

RBM is rare in children. The majority of children with RBM had predisposing conditions including congenital/acquired anatomical defects and immunodeficiency. Interventions should be implemented to solve the underlying conditions to avoid RBM.

Prevalence and Outcome of Anterior and Middle Cranial Fossae Encephaloceles without Cerebrospinal Fluid Leak or Meningitis

BACKGROUND

With advances in imaging techniques, encephaloceles, meningoceles, and meningoencephaloceles are occasionally discovered incidentally. These can be located in anterior cranial fossa (ACF), mostly protruding into sphenoid and ethmoid sinuses, or middle cranial fossa (MCF), protruding into the temporal bone. We reviewed a large series of cranial computed tomography and magnetic resonance imaging scans to identify the prevalence of asymptomatic encephaloceles, meningoceles, and meningoencephaloceles and describe their outcome.

METHODS

We retrospectively reviewed a database of all magnetic resonance imaging and computed tomography scans done at Weill Cornell Medicine for any reason between 2003 and 2018. Encephaloceles, meningoceles, or meningoencephaloceles were confirmed on 72 scans. Of these, chart reviews were performed to identify incidentally discovered cases with symptoms other than cerebrospinal fluid leak, and chart reviews and phone calls were conducted to determine patient demographics, treatment, and outcome.

RESULTS

There were 18 incidental cases for a prevalence of 0.0074%, of which 6 were located in ACF, and 12 were located in MCF. The mean age for ACF cases was 39 ± 15.9 years and for MCF cases was 49.5 ± 19.8 years. There were no leaks in any cases after the encephaloceles were discovered. Eleven of 12 (91.6%) MCF cases were treated conservatively, while 3 of 6 (50%; P = 0.083) ACF cases were treated surgically.

CONCLUSIONS

This study showed that encephaloceles, meningoceles, and meningoencephaloceles without cerebrospinal fluid leak or meningitis in MCF were more often conservatively managed with observation only, whereas these entities in ACF were often repaired prophylactically. Incidentally discovered encephaloceles have a relatively benign natural history and do not precipitously leak.

What's that smell? A pictorial review of the olfactory pathways and imaging assessment of the myriad pathologies that can affect them

The olfactory pathway is composed of peripheral sinonasal and central sensorineural components. The wide variety of different pathologies that can affect the olfactory pathway reflect this complex anatomical relationship. Localising olfactory pathology can present a challenge to the reporting radiologist. This imaging review will illustrate the normal anatomy of the olfactory system and describe a systematic approach to considering olfactory dysfunction. Key concepts in image interpretation will be demonstrated using examples of olfactory pathway pathologies.

Prevalence of Sigmoid Sinus Dehiscence and Diverticulum among Adults with Skull Base Cephaloceles

BACKGROUND AND PURPOSE

Cephaloceles are relatively rare conditions caused by a congenital and/or acquired skull defect. The incidence of associated venous brain anomalies with regard to cephaloceles remains to be fully elucidated. Accordingly, we sought to assess the prevalence of sigmoid sinus dehiscence and diverticula in patients with spontaneous skull base cephaloceles.

MATERIALS AND METHODS

Our institutional data base was retrospectively queried from 2005 to 2018. Patients in whom spontaneous skull base cephaloceles were identified were ultimately included in the study cohort. These patients subsequently had their sigmoid sinuses re-evaluated with focused attention on the possible presence of dehiscence and/or diverticula.

RESULTS

We identified 56 patients: 12 men and 44 women. After re-evaluation of the sigmoid sinuses, evidence of dehiscence and/or diverticula was noted in 21 patients. The right sigmoid sinus was involved in 11 patients, and the left sigmoid sinus was involved in 7 patients, including 3 cases of diverticulum. In 3 patients, evidence of bilateral sigmoid sinus dehiscence and diverticula was noted. Female sex was associated with sigmoid sinus dehiscence and diverticula by univariate analysis (P = .019). By linear regression, cephalocele volume was negatively associated with sigmoid sinus dehiscence and diverticula (coefficient, -2266, P value < .007, adjusted R ² = 0.1077). By univariate logistic regression using average cephalocele volume as a cutoff, we demonstrate a statistically significant finding of lower volumes being associated with sigmoid sinus dehiscence and diverticula with an odds ratio of 3.58 (P = .05).

CONCLUSIONS

The prevalence of sigmoid sinus dehiscence and diverticula in patients with cephalocele is high. Female sex is associated with sigmoid sinus dehiscence and diverticula. The cephalocele volume appears to be inversely proportional to sigmoid sinus dehiscence and diverticula.

Overview on neural tube defects: From development to physical characteristics

Neural tube defects (NTDs) are the second most common congenital malformations in humans affecting the development of the central nervous system. Although NTD pathogenesis has not yet been fully elucidated, many risk factors, both genetic and environmental, have been extensively reported. Classically divided in two main sub-groups (open and closed defects) NTDs present extremely variable prognosis mainly depending on the site of the lesion. Herein, we review the literature on the histological and pathological features, epidemiology, prenatal diagnosis, and prognosis, based on the type of defect, with the aim of providing important information based on NTDs classification for clinicians and scientists.

Transnasal transpterygoid resection of meningoencephalocoele with abolition of seizures

Meningoencephalocoeles are herniations of intracranial contents through skull base defects. Patients may present with a plethora of symptoms ranging from cerebrospinal fluid (CSF) rhinorrhoea to epileptic convulsions, or indeed may be asymptomatic. We present a case of a 24-year-old man suffering from new onset, drug-resistant tonic-clonic seizures. Imaging studies revealed neural tissue and meninges protruding through the pterygoid portion of the sphenoid bone, into the anteromedial aspect of the middle cranial fossa. An image-guided endoscopic transnasal transpterygoid approach was carried out as a joint otolaryngological and neurosurgical procedure, resulting in the patient being seizure-free for over 12 months postoperatively. There is a paucity of literature supporting such an endoscopic approach to treat epilepsy secondary to a meningoencephalocoele. We illustrate that this is a safe and minimally invasive treatment option which ultimately rendered the patient free of all anticonvulsants.

Intrasphenoidal Encephalocele with Spontaneous Cerebrospinal Fluid Rhinorrhea in Idiopathic Intracranial Hypertension: Need for Clarity in Terminology and Imaging Delineation

BACKGROUND

Magnetic resonance imaging plays an important role in identification of any underlying structural cause in spontaneous cerebrospinal fluid (CSF) leaks-either rhinorrhea or otorrhea. Sphenoid bone defects have been reported in those presenting as idiopathic intracranial hypertension with or without CSF rhinorrhea. Sphenoid lateral recess defect with intrasphenoidal encephalocele is one of the uncommon causes of spontaneous CSF leakage. Many classifications of basal encephaloceles have been used along with associated predisposing anatomic factors for the CSF leak.

CASE DESCRIPTION

We report 2 cases of spontaneous CSF rhinorrhea in 2 middle-aged females and had intrasphenoidal encephalocele on imaging using 3-dimensional magnetic resonance cisternography and computed tomography.

CONCLUSIONS

We discuss the various classification systems of sphenoidal encephaloceles and review the terminology and comprehensive imaging details to be included in reporting such cases for appropriate treatment planning.

New detailed description of the anterior part of the cribriform plate using anatomic specimens and computed tomography

PURPOSE

Ethmoidal slit (ES) and cribroethmoidal foramen (CF) have been poorly studied, without any radiological description. They may ease cribriform plate's diseases. The objective was to describe the frequency, size, and computed tomography (CT) appearance of these foramina.

METHODS

A two-part anatomoradiological study was performed: first on dry skulls using a surgical microscope and CT, second on patients CT scans. For each, foramina were searched for, described, and measured when possible.

RESULTS

Thirteen dry macerated skulls were studied. The orbitomeatal plane was relevant for studying ES. With microscope, ES and CF were identified in, respectively, 92% and 100% of cases. Using CT, all ES and CF were visible, with a mean length and width of, respectively, 3.9 ± 1.7 mm and 0.9 ± 0.3 mm for ES and 1.6 ± 1 mm and 0.9 ± 0.3 mm for CF. CT scans from 153 patients were reviewed. ES and CF were identified in, respectively, 80% and 91% of cases, with a mean length and width of, respectively, 3.9 ± 0.8 mm and 0.8 ± 0.2 mm for ES.

CONCLUSION

Large-sized ES was found frequently, and were clearly visible in patients CT scans. CF was markedly smaller, but seen in most patient scans. ES and CF could be areas of least resistance in the anterior part of the cribriform plate. CT might be helpful in understanding their pathological implications.

A Case of An Unusual Bell's Palsy Mimic

We discuss the case of a 5-year-old boy who presented with an isolated left-sided cranial nerve 7 palsy that was initially magnetic resonance imaging negative. Owing to continued symptoms, repeat magnetic resonance imaging was performed and showed a temporal bone encephalocele. A review of the differential diagnosis of cranial nerve 7 palsy, warning signs signaling the need for additional workup, and a discussion of temporal lobe encephaloceles is provided in this case report. It is important to recognize that structural lesions can closely mimic idiopathic Bell's palsy, despite initial negative imaging.

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.

Spontaneous cerebrospinal fluid rhinorrhea: A case report and analysis

INTRODUCTION

Spontaneous cerebrospinal fluid leakage is usually caused by developmental abnormalities and is rare, accounting for approximately 5% of the cases of cerebrospinal fluid (CSF) leakage. To the best of our knowledge, clival dysplasia-caused CSF rhinorrhea has never been reported in the neurosurgical field.

CONCLUSION

Spontaneous cerebrospinal fluid rhinorrhea is often treated by surgery, and a transsphenoidal approach repair is the main surgical method used, offering the advantages of less trauma, fewer complications, rapid postoperative recovery, and low recurrence rate.

Spontaneous cerebrospinal fluid leaks in the anterior skull base secondary to idiopathic intracranial hypertension

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.

Spontaneous cerebrospinal fluid leaks in the anterior skull base: a surgical challenge

OBJECTIVE

This retrospective study aimed to evaluate the effective closure rate for spontaneous cerebrospinal fluid leaks with functional endoscopic sinus surgery and identify patient characteristics that may be associated with a need for additional therapy.

METHOD

A retrospective analysis of patients with spontaneous cerebrospinal fluid leaks was performed. Data on the nature of presentation, patient body mass index, defect location and size, intracranial pressure, clinical follow up, and complications were collected.

RESULTS

Twenty-five patients had spontaneous cerebrospinal fluid leaks with evidence of idiopathic intracranial hypertension. The most common sites were the cribriform plate, followed by the ethmoid roof and sphenoid lateral pterygoid recess. All patients underwent endonasal endoscopic surgery to repair the defect. Post-operatively, all patients underwent lumbar drainage and acetazolamide therapy.

CONCLUSION

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.

The endoscopic endonasal approach for cerebrospinal fluid leak repair in the elderly

INTRODUCTION

Cerebrospinal fluid (CSF) rhinorrhea can lead to CNS infections, carrying significant morbidity and mortality, especially in the elderly. Endoscopic endonasal surgery is a validated technique in the repair of anterior skull base CSF leaks. The aim of this study is to assess diagnostic management, surgical technique and clinical outcome in a consecutive series of elderly patients.

METHODS

Patients older than 65 years treated for anterior skull base CSF leaks through endoscopic endonasal surgery between 2003 and 2014 were retrospectively reviewed. All patients underwent preoperative nasal endoscopy, laboratory and radiological assessment. In doubtful cases endoscopic exploration was performed after intrathecal fluorescein (IF) injection. Patients were discharged between 3 and 4 days after surgery, and the endoscopic follow-up ranged from 3 to 24 months.

RESULTS

20 patients (age range 65-92) presented with 10 spontaneous and 10 traumatic/iatrogenic CSF leaks. In 40% of patients formal rhinoscopy and radiological assessment did not localize the CSF leak and IF injection was performed. IF enabled the identification of the skull base defect in all cases, with no adverse effects. In 11 cases the dura was repaired with fascia lata graft. All patients had successful endoscopic repair of the CSF fistula with no complications nor recurrences during follow-up.

CONCLUSION

Endoscopic endonasal surgery is a minimally invasive procedure for CSF leak treatment. In our experience, IF injection proved safe and efficient in detecting skull base defects not identified by preoperative imaging. Endoscopic endonasal surgery proved effective and reliable also in elderly patients, with short hospitalization times and no morbidity.

Novel radiographic measurement algorithm demonstrating a link between obesity and lateral skull base attenuation

OBJECTIVES

(1) To describe a validated algorithm for measuring tegmen thickness on computed tomography scans. (2) To compare the tegmen thickness in 3 groups: patients with spontaneous cerebrospinal fluid (CSF) leaks, obese controls, and nonobese controls.

STUDY DESIGN

Retrospective review.

SETTING

Patients with spontaneous CSF otorrhea often have highly attenuated tegmen plates. This is associated with obesity and/or idiopathic intracranial hypertension (IIH). No evidence exists, however, that objectively links obesity and/or IIH with skull base attenuation.

SUBJECTS AND METHODS

This was a retrospective review from 2004 to the present. Patients with spontaneous CSF otorrhea and matched obese (body mass index [BMI] >30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) controls were selected. Tegmen thickness was measured radiographically. Interrater validity was assessed.

RESULTS

Ninety-eight patients were measured: 37 in the CSF group (BMI, 36.6 kg/m(2)), 30 in the obese group (BMI, 34.6 kg/m(2)), and 31 in the nonobese group (BMI, 24.2 kg/m(2)). The CSF group had a significantly thinner tegmen compared to both the obese control (P < .01) and nonobese control (P = .0004) groups. Obese controls had a thinner tegmen than nonobese controls (P < .00001). A significant inverse correlation was detected between skull base thickness and BMI. Signs/symptoms of IIH were most commonly found in the CSF group. Good to very good strength of agreement was detected for measures between raters.

CONCLUSION

This is the first study to (1) quantify lateral skull base thickness and (2) significantly correlate obesity with lateral skull base attenuation. Patients who are obese with spontaneous CSF leaks have greater attenuation of their skull base than matched obese controls. This finding supports theories that an additional process, possibly congenital, has a pathoetiological role in skull base dehiscence.

Combined approach for tegmen defects repair in patients with cerebrospinal fluid otorrhea or herniations: our experience

Objectives To describe our departmental experience in the surgical repair of tegmen tympani defects using a combined transmastoid/minicraniotomic approach. Design Retrospective review of videos from surgery and patients' charts. Setting Tertiary university referral center. Participants Twenty-two patients who underwent surgical repair of tegmen defects associated with cerebrospinal fluid (CSF) leakage and/or meningocele/meningoencephalocele by a combined transmastoid/minicraniotomic approach. Main Outcome Measures A retrospective review of videos of surgery and charts of patients with tegmen tympani or tegmen antri defects and CSF leakage, temporal lobe encephalocele, and/or meningoencephalocele. Results All patients underwent the combined approach and had their defects closed, without significant intraoperative or postoperative complications. Conclusions Mastoidectomy with temporal minicraniotomy represents an effective approach in patients with tegmen tympani dehiscence; the advantages of this technique are the control of the floor of the middle cranial fossa and the possibility to reach bony defects located anteriorly without manipulation of the ossicular chain and temporal lobe.

Spontaneous lateral sphenoid cephaloceles: anatomic factors contributing to pathogenesis and proposed classification

SUMMARY

Spontaneous lateral sphenoid cephaloceles arise from bony defects in the lateral sphenoid, in the absence of predisposing factors such as trauma, surgery, mass, or congenital skull base malformation. We reviewed CT and MR imaging findings and clinical data of 26 patients with spontaneous lateral sphenoid cephaloceles to better understand anatomic contributions to pathogenesis, varying clinical and imaging manifestations, and descriptive terminology. Two types of spontaneous lateral sphenoid cephaloceles were identified. In 15 of 26 patients, a type 1 spontaneous lateral sphenoid cephalocele was noted, herniating into a pneumatized lateral recess of the sphenoid sinus, and typically presenting with CSF leak and/or headache. In 11 of 26 patients, a type 2 spontaneous lateral sphenoid cephalocele was noted, isolated to the greater sphenoid wing without extension into the sphenoid sinus, presenting with seizures, headaches, meningitis, cranial neuropathy, or detected incidentally. All patients had sphenoid arachnoid pits, and 61% of patients had an empty or partially empty sella, suggesting that altered CSF dynamics may play a role in their genesis.

The man with a persistently runny nose

Cerebrospinal fluid (CSF) rhinorrhea is rarely seen in the emergency department (ED) and most often occurs after a traumatic event. Spontaneous CSF leaks are much less common and are often the result of benign intracranial hypertension. If not recognized early on, CSF infections are the most serious consequence of this condition and therefore its early diagnosis and treatment are essential. This case report describes a patient who presented to the ED with a CSF leak not caused by a traumatic event. The patient presented with persistent unilateral rhinorrhea and headache that had previously been misdiagnosed. It describes the importance of early diagnosis and treatment of this serious condition. This is a case report of an uncommon but potentially dangerous disease that carries high morbidity if not diagnosed and treated early. This disease must be considered in the differential diagnosis of any patient who presents with persistent atraumatic unilateral rhinorrhea. Although CSF leaks have been portrayed in the literature, this case report is unique because it describes a rare manifestation of this condition and its diagnosis by emergency physicians. This article presents the case, discusses the incidence, potential causes, predisposing factors, diagnostic modalities and the course of treatment for this particular diagnosis.

Spontaneous Bilateral Meningoencephalocoeles of the Temporal Bones

Spontaneous tegmen tympani defects are rare with even rarer bilateral cases. The symptoms are nonspecific; hence, a high index of suspicion is required to prevent serious intracranial complications. We present a case of spontaneous bilateral tegmen tympani defects with associated meningoencephalocoeles in a 54-year-old male who presented with the signs and symptoms of severe meningitis. After careful workup which included a lumbar puncture, CT and MRI scans, both defects were repaired using a middle fossa approach. The patient made an uneventful recovery with complete cessation of otorrhoea and improvement in his hearing.

Inferior encephalocele: transpalatal repair using paired costal bone grafts with a 14-year follow-up

A 2-year-old girl was referred to our hospital because of a pulsating mass in the roof of the mouth. On examination, a mass measuring 4 × 5 cm was found in the roof of the mouth and nose with a secondary palatal cleft. She had hypertelorism, a bifid nose, and a visible cleft over the dorsum and skin of the nose. In 1 stage, the mass was opened, reduced, and repositioned into the cranial cavity, and the defect was repaired with 2 parallel bridges of split costal bone grafts. The bone grafts were placed between 2 layers of soft tissue and the mucosa repaired over it. Palatal cleft was repaired with the Veau-Wardill-Kilner method 1 year later. Fourteen years later, the bifid nose was corrected using a flying-bird incision and a costal cartilage graft for the dorsum of the nose. On follow-up, minimal scar remained on the tip of the nose. There was neither obliteration nor reduction in the size of the bony defect. There were no operative complications, and the shape of the nose improved. The patient and her parents were highly satisfied with the result.