Cerebrospinal Fluid (CSF) leakage results from a defect in the skull base, which communicates the subarachnoid space with the nasal cavity. The most common cause of CSF leakage is traumatic, and non-traumatic causes are less common. This case report illustrates a case of a woman who presented to the emergency department with clear fluid pouring from her nose for three weeks with a fever. The patient had pneumococcal meningitis and Idiopathic Intracranial Hypertension (ICH) seven years ago. Computed Tomography (CT) sinuses showed the defect seen on the right side of the cribriform plate, and the Magnetic Resonant Imaging (MRI) confirmed the CSF leakage. The CSF leakage was diagnosed by positive B transferrin.  This case highlights a rare condition that needs early detection and treatment to prevent complications such as ascending meningitis.

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

Introduction Cerebrospinal fluid (CSF) rhinorrhea is the result of a bony defect at the skull base with disruption of the arachnoid, dura mater, and sinonasal mucosa that leads to an active CSF leak and flow of clear fluid from the nose. The endoscopic repair of CSF leaks and skull defects have been used by an increasing number of surgeons and is the standard of care for repairing CSF leaks. Materials and methods We conducted a retrospective study of all cases of CSF leaks managed via the endonasal endoscopic approach from 2010 to 2020 at a tertiary referral hospital of King Fahad Specialist Hospital, Dammam (KFSH-D). Results Over 10 years, 61 procedures were performed on a total of 56 patients (average age, 39.9 years) with 26 spontaneous CSF leaks and 30 traumatic CSF leaks. The leak sites were frontal bone in 14% of the cases, the roof of the ethmoid in 25%, the cribriform plate of ethmoid in 39%, and the walls of sphenoid sinus in 21%; multiple site defects were found in eight patients. The defect was localized by high-resolution computed tomography (CT) of the paranasal sinuses and skull base and magnetic resonance imaging (MRI) in all patients. CT cisternography, intrathecal fluorescein injection, and topical application of fluorescein dye were used in patients as required. A combination of free grafts and flaps materials were used in most patients. A middle and inferior turbinate graft was used in 12 patients, a septal cartilage graft in 18 patients, and a pedicled nasoseptal flap in 12 patients. The success rate was 92% after the first closure attempt. A recurrence of CSF leaks was observed in four patients. The mean hospitalization time was 6.5 days. The postoperative follow-up period ranged from one year to 10 years with a mean postoperative follow-up time of three years. Conclusions The endonasal endoscopic approach is the current standard of care for repairing most CSF leaks and skull base defects. We have had an excellent experience with endonasal endoscopic CSF leak repair, with high success rates and low morbidity. Our results support the effectiveness and safety of this technique and should encourage otolaryngologists to apply the procedure in cases of CSF leak.

The association between spontaneous cerebrospinal fluid (CSF) leak/rhinorrhea and idiopathic intracranial hypertension (IIH) has been increasingly recognized over the last years. However, considerable variability of opinion regarding the assessment, investigations, and management of patients with spontaneous CSF rhinorrhea remains.
A consensus group was formed from experts from Europe, Asia, Australia, South and North America. Following literature review and open discussions with members of the panel, a set of 61 statements was produced. A modified Delphi method was used to refine expert opinion with 3 rounds of questionnaires and a consensus group meeting in Santo-Rhino meeting in September 2019.
Fifty statements (82% of total) on spontaneous CSF leak and IIH reached consensus. In 38 of 50 statements, the median response was 7 (strongly agree) and in the 12 remaining statements the median response was 6 (agree). Eleven statements were excluded because they did not reach consensus and one new statement was added during SantoRhino meeting. The final statements refer to patient history and clinical examination (\"History taking should include presence of headache, tinnitus and visual defects\"), investigations (role of Thin Slice Computed Tomography and CISS/FLAIR sequences in Magnetic Resonance Imaging), principles of management (watchful waiting or measures to reduce ICP are supplementary but cannot subsitute surgical closure), surgical technique, intraoperative, early postoperative and long term management.
We present fifty consensus statements on the diagnosis, investigation, and management of spontaneous CSF rhinorrhea based on the currently available evidence and expert opinion. Although by no means comprehensive and final, we believe they can contribute to the standardization of clinical practice. Early diagnosis, prompt surgical closure of the defect, assesment for and treatment of potentially co-existing idiopathic intracranial hypertension in a comprehensive multidisciplinary approach are essential in order to successfully manage spontaneous CSF rhinorrhea, reduce associated morbidity and prevent recurrence.

Most spontaneous CSF leaks (SCSFL) are associated with an underlying pseudotumor cerebri syndrome (PTCS). Treatment generally includes surgical leak repair and PTCS correction, as untreated PTCS carries a risk of recurrence. We describe a 72-year-old woman with rhinorrhea, aural fullness, and posterior nasal drip. CT and MRI showed signs of CSF hypovolemia and PTCS, as well as bilateral transverse sinus stenoses. CT and MRI cisternography documented CSF leaks through the right cribriform plate and the posterior aspect of the petrous bone. Opening CSF pressure was 6 cm H2O. Dural venous sinus stenting (DVSS) was performed after failed conservative treatment. Rhinorrhea resolved 3 days after stenting, aural fullness 1 month later. After 6 months, signs of CSF hypovolemia had disappeared on MRI and the stents were patent. After 9 months, the patient had a transient, spontaneously resolving episode of rhinorrhea. She has been symptom-free for the remaining 39 months of follow-up.

Dural membrane is an important anatomic structure that surrounds and protects the entire central nervous system. Physical properties of the dura have many pathophysiological and therapeutic implications in cranial surgery, especially skull base disorders. The aim of this study is to investigate variation in skull base dural thickness and correlation with different demographic parameters. At the time of autopsy, the petrous apex dura with the underlying bone of 20 cadavers was harvested. Dural thickness was independently measured by two pathologists at the thinnest and thickest segments in the specimen. Correlational analyses were then performed to compare dural thickness with gender, age, neck circumference, height, weight, and body mass index (BMI). Mean, minimum, and maximum skull base dural thickness in our study was 0.36, 0.27, and 0.46 mm, respectively. Age demonstrated a negative correlation with dural thickness with significantly thinner dura in the older subjects, p  = 0.01. There was a trend toward thinner dura in females that approached statistical significance, p  = 0.06. No strong correlation could be found with body weight, height, neck circumference, or BMI. Our findings show a considerable intersubject and intrasubject variability in skull base dural thickness. Some demographic parameters also seem to impact dural thickness. Additional histological studies are needed for better understanding of the pathophysiological mechanisms pertaining to the tensile properties of the dural membrane.

Endoscopic repair of anterior skull-base defects has become the gold standard for management of cerebrospinal fluid (CSF) rhinorrhea. Both improved techniques and adjuvant therapies have led to accepted success rates of greater than 90%. As management has evolved, shorter hospitalizations have been required and the goal of this study is to analyze the outcomes of patients repaired on an outpatient basis vs those managed as inpatients postoperatively.
Patients undergoing endoscopic repair of CSF rhinorrhea between 2004 and 2014 were identified by review of medical records. Demographic and clinical data were collected and compared between patients having surgery with and without postoperative admission. Patients managed with lumbar drains were not included. Statistical analyses were preformed to determine if any differences in patient demographics and outcomes existed.
A total of 86 patients were identified; 39 of 86 patients (45.3%) underwent outpatient surgery; 47 patients were admitted postoperatively with a mean hospital stay of 1.66 days with a median and mode of 1 day. No statistically significant differences were found between leak location, etiology, rates of recurrence, or complications. The outpatient group was found to have a greater proportion of small defects <1 cm2 (p = 0.003). Repair technique was also significantly different between groups (p = 0.001).
Endoscopic management of CSF rhinorrhea is a safe method of treatment with reliable success rates. Our retrospective analysis revealed comparable outcomes in patients treated with and without postoperative hospital admission, and supports the idea that outpatient management may be reasonable in certain patients, especially those with defects <1 cm2 .

OBJECTIVE: The current approach for the diagnosis and repair of spontaneous and traumatic anterior skull-base defects is oulined, highlighting the controversies that exist in the field and describing the strategies required to access different segments of the anterior cranial fossa.
METHODS: We reviewed the literature concerning endoscopic management of anterior skull-base defects. These publications have been combined with our own experience repairing cerebrospinal fluid (CSF) leaks and encephaloceles that developed spontaneously, traumatically, or intentionally as a result of endoscopic skull-base surgery.
RESULTS: We present a systematic methodology for the repair of these defects. We have divided our surgical approach into four separate corridors. These are the transnasal, transsphenoidal, transethmoidal, and transmaxillary corridors. Dissection strategies vary for each corridor, but with a combination of approaches, all areas of the anterior skull base can be accessed. Skull-base defects are successfully repaired with a multilayered closure that often involves use of a vascularized pedicled mucosal flap. Adoption of this technique has decreased our rate of postoperative CSF leak from 5.9%-3.1%.
CONCLUSIONS: Endoscopic endonasal repair of CSF leaks and encephaloceles has evolved significantly during the past decade. The versatility of different endoscopic approaches through the four endonasal corridors allows for the endoscopic repair of almost all skull-base defects. The use of vascularized pedicled mucosal flaps has evolved to cover these defects as part of multilayered closure strategies.

OBJECTIVE: Spontaneous cerebrospinal fluid (CSF) leaks typically present in patients with undiagnosed idiopathic intracranial hypertension (IIH) secondary to pressure erosion of the skull base. Despite elevated intracranial pressure (ICP) on lumbar puncture or ventriculostomy, patients with spontaneous CSF leaks rarely complain of visual disturbances. The objective of this study is to correlate the presence of preoperative papilledema with opening ICP in patients undergoing endoscopic repair of spontaneous CSF leaks.
METHODS: Prospective study.
METHODS: Tertiary hospital.
METHODS: Prospective evaluation of patients with spontaneous CSF leaks was performed over a 1-year period (December 2012 to December 2013). Fundoscopic examination for papilledema was completed preoperatively and CSF pressure measured by lumbar puncture or ventriculostomy intraoperatively. Data regarding demographics, nature of presentation, and body mass index (BMI) were also recorded and compared to a control cohort of IIH patients with papilledema.
RESULTS: Sixteen patients (average age 52) were evaluated. Obesity was present in 94% of individuals (average BMI = 43, range, 27-65). Papilledema was absent preoperatively in all subjects. Opening pressures via lumbar puncture/ventriculostomy were 27.4 ± 7.7 cmH20. Following 6 hours of clamping, measurements significantly increased to 36 ± 9.6 cmH20 (P < .001). IIH controls (average age 33, average BMI = 36, range, 21-52) exhibited average ICP (36.2 ± 11.7) identical to postclamp measurements in the spontaneous CSF leak cohort.
CONCLUSIONS: Subjects with spontaneous CSF leaks had postclamping average ICP identical to controls with IIH and papilledema. Such evidence suggests that a CSF leak in this patient population provides sufficient pressure diversion to avoid the development of papilledema.

Practically all cases of spontaneous intracranial hypotension results from spontaneous cerebral spinal fluid (CSF) leaks, often at the level of the spine and only rarely from the skull base. The triad of orthostatic headaches, diffuse pachymeningeal enhancement on head imaging and low CSF opening pressure is considered the hallmark of these leaks but substantial variability is noted in most aspects of this disorder including in features of the headaches, imaging and CSF findings, response to treatment and outcome.