Multimodal diagnosis of cerebrospinal fluid rhinorrhea: State of the art review and emerging concepts

Objective

Currently, diagnosis of cerebrospinal fluid (CSF) rhinorrhea relies on a multimodal approach, increasing costs and ultimately delaying diagnosis. In the United States and internationally, the crux of such a diagnosis relies on confirmation testing (via biomarkers) and localization (e.g., imaging). Biomarker testing may require analysis at an outside facility, resulting in delays diagnosis and treatment. In addition, specialized imaging may be nonspecific and often requires an active leak for diagnosis. There remains a clear need for innovative new technology.

Methods

A comprehensive review was conducted on both foundational and innovative scholarly articles regarding current and emerging diagnosis modalities for CSF.

Results

Current modalities in CSF rhinorrhea diagnosis and localization include laboratory tests (namely, B2T immunofixation), imaging (CT and/or MRI) with or without intrathecal administration, and surgical exploration. Each of these modalities carry flaws, risks, and benefits, ultimately contributing to delays in diagnosis and morbidity. Promising emerging technologies include lateral flow immunoassays (LFI) and biologically functionalized field-effect transistors (BioFET). Nevertheless, these carry some drawbacks of their own, and require further validation.

Conclusion

CSF rhinorrhea remains a challenging diagnosis, requiring a multimodal approach to differentiate from nonpathologic causes of rhinorrhea. Current methods in diagnosis are imperfect, as the ideal test would be a readily accessible, inexpensive, rapid, highly accurate point-of-care test without the need for excess fluid or specialized processing. Critical work is being done to develop promising, new, improved tests, though a clear successor has not yet emerged.

Level of Evidence

N/A.

SNOT-22 Quality of Life Scores Improve After Endoscopic Endonasal Repair of Spontaneous Cerebrospinal Fluid Rhinorrhea

OBJECTIVES

Patients with spontaneous cerebrospinal fluid (CSF) rhinorrhea can experience significant sinonasal symptom burden, leading to poor quality of life (QOL). The objective of this study was to investigate sinonasal outcome test-22 (SNOT-22) scores in patients undergoing endoscopic endonasal surgery for spontaneous CSF rhinorrhea and compare them to patients undergoing endoscopic sinus surgery (ESS) for chronic rhinosinusitis without nasal polyps (CRSsNP).

METHODS

A multi-institutional retrospective review of patients with spontaneous CSF rhinorrhea and CRSsNP was performed. Pre-surgery and post-surgery SNOT-22 scores and domains were compared within each group. Improvements in SNOT-22 scores after surgery were compared between the groups.

RESULTS

Ninety-one patients were in the CSF rhinorrhea group and 105 patients were in the CRSsNP group. Within each group, surgery significantly improved total SNOT-22 scores, domain scores, and most of the individual symptoms. Comparing the 2 groups revealed similar improvements in total SNOT-22 scores (P = .244). The CSF rhinorrhea group improved more in runny nose (P < .001), postnasal discharge (P < .001), wake up at night (P = .024), and embarrassed (P = .002). The CRSsNP group improved more in sneezing (P = .027), nasal blockage (P < .001), decreased sense of smell/taste (P = .011), thick nasal discharge (P < .001), facial pain/pressure (P = .008), and the ear/facial domain (P = .010).

CONCLUSIONS

Patients with spontaneous CSF rhinorrhea experience significant symptom burden. Those who undergo CSF leak repair should experience significant improvement in QOL similar to patients who undergo ESS for CRSsNP as measured by SNOT-22.

Immediate CPAP Use after Skull Base Reconstruction with Hydroxyapatite Bone Cement

OBJECTIVE

The timing for resuming continuous positive airway pressure (CPAP) postoperatively after skull base surgery remains controversial because of the risk of pneumocephalus. We determined the safety of immediate CPAP use after middle cranial fossa (MCF) spontaneous cerebrospinal fluid (sCSF) leak repair with bone cement.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary academic medical center.

PATIENTS

Thirteen consecutive patients with CPAP-treated obstructive sleep apnea and temporal bone sCSF leaks who underwent skull base repair with hydroxyapatite bone cement between July 2021 and October 2022.

INTERVENTIONS

CPAP use resumed on postoperative day 1 after the confirmation of skull base reconstruction with temporal bone computed tomography (CT).

MAIN OUTCOME MEASURES

Postoperative skull base defects on CT, pneumocephalus, or intracranial complications.

RESULTS

The average age was 55.5 ± 8.8 years (±standard deviation), and 69.2% were female with a BMI of 45.39 ± 15.1 kg/m 2 . Multiple tegmen defects were identified intraoperatively in 53.9% of patients with an average of 1.85 ± 0.99 defects and an average defect size on preoperative imaging of 6.57 ± 3.45 mm. All patients had an encephalocele identified intraoperatively. No residual skull base defects were observed on CT imaging on postoperative day 1. No postoperative complications occurred. One patient developed a contralateral sCSF leak 2 months after repair. There were no recurrent sCSF leaks 1 month postoperatively.

CONCLUSION

Immediate postoperative CPAP use is safe in patients undergoing MCF sCSF leak repair with bone cement because of the robust skull base repair.

Optic nerve sheath diameter correlates to intracranial pressure in spontaneous CSF leak patients

BACKGROUND

Spontaneous cerebrospinal fluid (sCSF) leaks develop from pressure erosion due to idiopathic intracranial hypertension, treatment of which is paramount to preventing recurrence. Direct measurements of intracranial pressure (ICP) for monitoring response to treatment via lumbar drain (LD) or ventriculostomy are invasive and have risks. The objectives of this study are to determine whether ultrasonographic measurements of optic nerve sheath diameter (ONSD) correlate with LD ICP in patients with sCSF leaks undergoing treatment, and whether ONSDs are larger in patients with sCSF leaks than controls.

METHODS

Subjects with sCSF leaks and controls were prospectively recruited. ONSD, sex, and body mass index (BMI) were analyzed. For sCSF leak subjects, ultrasonography was performed at the time of LD opening and each pressure check postoperatively, including the acetazolamide response. In control patients, measurements were obtained at the time of surgery. Pearson's correlation between ONSD and ICP was performed.

RESULTS

Subjects with sCSF leaks (n = 9, age 52.4 ± 9.5, all female) and controls (n = 8, age 60.1 ± 14.8, two females) had significantly different BMIs, 38.4 ± 8.1 vs. 29.2 ± 4.8, t(15) = 2.793, p = 0.014. ONSD was strongly correlated with ICP measurements (r = 0.583, p = 0.002). However, percentage change in ONSD and ICP measurements were more strongly correlated (r = 0.733, p < 0.001). Patients with sCSF leaks had significantly higher ONSDs than controls, 0.63 cm ± 0.044 vs. 0.56 cm ± 0.074, t(15) = 2.329, p = 0.034.

CONCLUSION

ONSD significantly correlated with ICP in sCSF leak patients and was wider in sCSF leak subjects than controls. Ultrasonography has utility in monitoring the ICP response to acetazolamide.

The expanding spectrum of idiopathic intracranial hypertension

Once considered a rare and often difficult diagnosis in the era predating routine MRI, idiopathic intracranial hypertension has become an everyday concern in ophthalmology and neurology clinics where, especially in the latter, essentially every young overweight woman with headaches is initially presumed to have IIH. Has the diagnosis of IIH become too easy, and are we over-diagnosing IIH in this period of an accelerating obesity crisis? Or are we actually missing cases of IIH because they do not fit the classic clinical profile? We think it is both: at the same time IIH is being diagnosed in excess in obese women without papilledema, often resulting in unnecessary procedures, inappropriate treatment and even iatrogenic complications, the spectrum of this disorder is expanding to include a broad array of clinical presentations that involve multiple specialists beyond just the ophthalmologist and neurologist.

Remote cerebellar hemorrhage following repeated lumbar punctures

BACKGROUND

Remote cerebellar hemorrhage (RCH) is a rare complication in neurosurgery. No case of RCH secondary to repeated lumbar punctures (LPs) has been previously reported.

CASE PRESENTATION

A 49-year-old man presented with impaired consciousness following persistent fever. Cerebrospinal fluid examination showed high opening pressure, elevated white blood cells, increased protein level, and decreased glucose level, resulting in a diagnosis of bacterial meningoencephalitis. Treatment with repeated LPs and intrathecal injection of ceftriaxone resulted in an improvement in neurological symptoms. However, on day 31 of treatment, brain magnetic resonance image (MRI) showed streaky bleeding in bilateral cerebellum (zebra sign), leading to a diagnosis of RCH. Close observation and repeated brain MRI imaging without specific treatments led to the absorption of bilateral cerebellar hemorrhage, and the patient was discharged with improved neurological symptoms. Repeated brain MRI scans one month after discharge showed that bilateral cerebellar hemorrhage had improved, and had disappeared one year after discharge.

CONCLUSION

We reported a rare occurrence of LPs-induced RCH presenting as isolated bilateral inferior cerebellar hemorrhage. Clinicians should be vigilant of the risk factors for RCH, closely monitoring patients' clinical symptoms and neuroimaging findings to determine the need for specialized treatment. Furthermore, this case highlights the importance of ensuring the safety of LPs and managing any potential complications appropriately.

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.

The critical importance of a vascularized flap in preventing recurrence after endoscopic repair of spontaneous cerebrospinal fluid leaks and meningoencephaloceles

OBJECTIVE

Spontaneous CSF leaks into the anterior skull base nasal sinuses are often associated with meningoencephaloceles and occur in patients with idiopathic intracranial hypertension (IIH). Endonasal endoscopic repair has become the primary method of choice for repair. The authors sought to evaluate the success rate of endoscopic closure and to identify predictive factors for CSF leak recurrence.

METHODS

A consecutive series of endonasally repaired anterior skull base meningoencephaloceles was drawn from a prospectively acquired database. Lumbar punctures were not performed as part of a treatment algorithm. All patients had at least 5 months of follow-up. Chart review and phone calls were used to determine the timing and predictors of recurrence. Demographic information and details of operative technique were correlated with recurrence. Two independent radiologists reviewed all preoperative imaging to identify radiographic markers of IIH, as well as the location and size of the meningoencephalocele.

RESULTS

From a total of 54 patients there were 5 with recurrences (9.3%), but of the 39 patients in whom a vascularized nasoseptal (n = 31) or turbinate (n = 8) flap was used there were no recurrences (p = 0.0009). The mean time to recurrence was 24.8 months (range 9-38 months). There was a trend to higher BMI in patients whose leak recurred (mean [± SD] 36.6 ± 8.6) compared with those whose leak did not recur (31.8 ± 7.4; p = 0.182). Although the lateral recess of the sphenoid sinus was the most common site of meningoencephalocele, the fovea ethmoidalis was the most common site in recurrent cases (80%; p = 0.013). However, a vascularized flap was used in significantly more patients with sphenoid (78.3%) defects than in patients with fovea ethmoidalis (28.6%) defects (Fisher's exact test, p = 0.005). Radiographic signs of IIH were equally present in all patients whose leak recurred (75%) compared with patients whose leak did not recur (63.3%); however, an enlarged Meckel cave was present in 100% (2/2) of patients whose leaks recurred compared with 13.3% (4/30) of patients whose leaks did not recur (p = 0.03). The average meningoencephalocele diameter tended to be larger (1.73 ± 1.3 cm) in patients with recurrence compared to those without recurrence (1.2 ± 0.66 cm; p = 0.22). A ventriculoperitoneal shunt was already in place in 3 patients, placed perioperatively in 5, and placed at recurrence in 2, none of whose leaks recurred.

CONCLUSIONS

Recurrence after endonasal repair of spontaneous CSF leaks from meningoencephaloceles can be dramatically reduced with the use of a vascularized flap. Although failures of endonasal repair tend to occur in patients who have higher BMI, larger brain herniations, and no CSF diversion, the lack of vascularized flap was the single most important risk factor predictive of failure.

Recurrent spontaneous CSF rhinorrhea: combined endo-nasal endoscopic repair with lumbo-peritoneal shunt insertion

Background

Spontaneous cerebrospinal fluid (CSF) leaks are associated with high morbidity and recurrence rates. Most cases had increased intracranial pressure (ICP) on presentation. There is still controversy regarding the use of lumbo-peritoneal shunt to prevent its recurrence.

Aim

This study was conducted to evaluate the impact of lumbo-peritoneal CSF shunt following the initial as well as recurrent repair of spontaneous CSF leaks to avoid recurrence.

Methods

A retrospective cohort study reviewed patients with recurrent spontaneous CSF leaks over a 4-year period. All patients had increased ICP and were subjected to endoscopic repair and lumbo-peritoneal shunt procedure.

Results

Eighteen patients were included in this study. Most patients were obese (BMI = 33.6 ± 1.8 kg/m2) women (88.9%), with sleep apnea syndrome (77.8%). All patients presented with headache and visual complaints. Meningitis was recorded in two patients (11.1%). The most common sites of leakage were the cribriform (66.7%), followed by both cribriform and ethmoidal (16.7%), sphenoid (11.1%), and ethmoidal (5.6%) bones. The mean defect size was 5.1 ± 1.1 mm. About one third of cases had multiple defects. Encephalocele and meningocele were encountered in 61.1% and 66.7% of cases, respectively. The mean preoperative CSF pressure was 36.5 ± 1.7 mm H2O. Lumbo-peritoneal shunt was inserted for all our patients. The failure rate of repair was 11.1%.

Conclusion

Success rate is higher in patients with spontaneous CSF leaks and CSF hypertension treated by lumbo-peritoneal shunt. Future prospective studies with larger sample sizes should confirm the efficacy and safety of this management plan.

Cerebrospinal fluid dynamics along the optic nerve in patients with spontaneous cerebrospinal fluid rhinorrhea: a retrospective computed tomographic cisternography study

PURPOSE

Spontaneous cerebrospinal fluid (CSF) rhinorrhea is related to intracranial pressure (ICP) and dynamic changes. This study investigated CSF dynamics along the optic nerve (ON) in patients with spontaneous CSF rhinorrhea.

METHODS

The computed tomographic (CT) cisternographies of 66 patients (132 eyes) with spontaneous CSF rhinorrhea were analysed. The contrast-loaded CSF (CLCSF) density was measured in Hounsfield units (HU) at three regions of interest (ROIs) along the ON and adjusted by the basal cistern density. The CLCSF density and ON sheath diameter (ONSD) were analysed between both sides in the different ICP groups.

RESULTS

When comparing the density of CLCSF along the ON, no significant differences were found between the ipsilateral and contralateral sides of the leakage. The distribution of CLCSF along the ON showed a highly significant density reduction from the canalicular segment to the bulbar segment on both sides. The CLCSF density significantly decreased on the ipsilateral ON in the canalicular segment and tended to decrease on the ipsilateral ON in the bulbar and canal segments compared with that on the contralateral ON in the low-ICP group. The ONSD tended to decrease on the ipsilateral side of leakage.

CONCLUSIONS

According to the CLCSF density on CT cisternography, CSF dynamics along the ON may bilaterally decrease from the optic canal to the retrobulbar segment. Cerebrospinal fluid (CSF) dynamics are possibly influenced by differences in ICP, and a lower ICP may cause more obvious differences or impairments in CSF dynamics along the ipsilateral ON.

Prediction of Postoperative Risk of Raised Intracranial Pressure After Spontaneous Skull Base Cerebrospinal Fluid Leak Repair

BACKGROUND

A relationship between idiopathic intracranial hypertension and spontaneous skull base cerebrospinal fluid (CSF) leaks has been proposed, by which CSF leak decreases intracranial pressure (ICP) and masks the symptoms and signs of elevated ICP. These patients are at risk of developing papilledema, symptoms of elevated ICP, or a recurrent CSF leak after CSF leak repair. The objective of this study was to assess whether radiographic signs of raised ICP on preoperative magnetic resonance or computed venography (MRI or CTV) are predictors of postoperative papilledema, recurrence of CSF leak, or need for CSF shunt surgery.

METHODS

We performed a retrospective review of systematically collected demographics, fundus examination, and presurgical brain MRI and magnetic resonance venography/computed tomography venography (MRV/CTV) in patients seen at 1 institution between 2013 and 2019 with spontaneous skull base CSF leak repair. Patients were divided into 2 groups depending on whether they developed papilledema, recurrent CSF leak, or required CSF shunting (Group 1) or not (Group 2).

RESULTS

Fifty-seven patients were included, among whom 19 were in Group 1. There was no difference in demographic characteristics or clinical features between patients in Group 1 and Group 2. Controlling for other imaging features, bilateral transverse venous sinus stenosis (TVSS) on preoperative imaging increased the odds of being in Group 1 by 4.2 times (95% confidence interval [CI], 1.04-21.2, P = 0.04), optic nerve tortuosity decreased the odds of being in Group 1 by 8.3 times (95% CI: 1.4-74.6, P = 0.02).

CONCLUSION

Imaging of the intracranial venous system with MRV or CTV is warranted before repair of spontaneous CSF leak, as bilateral TVSS is an independent risk factor for postoperative papilledema, CSF leak recurrence, or need for a CSF shunting procedure.

MR findings suggestive of idiopathic intracranial hypertension in 117 patients with spontaneous cerebrospinal fluid rhinorrhea

PURPOSE

The purpose of this study is to document the prevalence of MR findings suggestive of idiopathic intracranial hypertension (IIH) in patients undergoing endoscopic repair of spontaneous CSF rhinorrhea (SCSFR).

METHODS

In a retrospective study, MR images of 117 consecutive patients who had undergone endoscopic repair of SCSFR were evaluated for features suggestive of IIH (empty sella, widened optic nerve sheath, tortuous optic nerve, flattened posterior globe, and enlarged Meckel's cave). Pituitary height was used to diagnose partial and complete empty sella. MR images were independently evaluated by two of the authors without knowledge of the clinical findings. Consensus method was used to resolve differences between the two evaluators.

RESULTS

Empty or partially empty sella was diagnosed in the MR of 105 (89.7%) patients. In 38/105 (36.2%) patients with empty/partial empty sella, no additional MR findings were present. In 43/105 (41%) patients, one or more of the MR features with high specificity for diagnosis of IIH (flattened posterior globe and enlarged Meckel's cave) were seen. In the other 24 (22.9%) additional MR findings, less specific for IIH (widened optic nerve sheath, tortuous optic nerve) were noted. Papilledema was seen in 11 of 60 (18.3%) patients who underwent funduscopic examination. All patients with papilledema had empty/partial empty sella, and 9/11 (81.8%) had an additional MR finding suggestive of IIH.

CONCLUSION

The majority of patients with SCSFR have MR imaging features of IIH. These imaging features should be a major component of previously published modified diagnostic criteria for IIH in patients with SCSFR.

Venous sinus stenting after repair of skull base spontaneous cerebrospinal fluid leaks: A single-center retrospective cohort series with case-control analysis

BACKGROUND

Management of idiopathic intracranial hypertension (IIH) is recommended after surgical repair of spontaneous cerebrospinal fluid leaks (sCSF-leaks) of the skull base for prevention of recurrence.

PURPOSE

To assess the feasibility of venous sinus stenting, a treatment commonly used for the treatment of IIH associated with intracranial venous sinus stenosis (VSS), after sCSF-leaks closure.

MATERIALS AND METHODS

A single-center cohort series of consecutive patients who underwent sCSF-leak closure was retrospectively analyzed. Stenting was considered either for leak recurrence or in prophylactic manner after repair in patients with VSS as confirmed by cerebral venous imaging. Leak recurrence, need for new repair or adjunctive treatment of IIH, meningitis, and stenting complications were determined at the last follow-up. Cases who had prophylactic stenting were compared to historical controls before stenting option.

RESULTS

Twenty-two patients had intracranial venous stenting after sCSF-leak closure. Their median age was 58 years (Q1=45; Q3=68), BMI=31 kg.m^-2 (Q1=27; Q3=36), and female rate=85%. The overall rate of successful repair after stenting was 95% (95% CI = 87-100%) at a median follow-up of 2.4 years (Q1=1.2; Q3=3.3). Adjunctive treatment for IIH was needed in 4 patients (4/22, 18%) including 2 patients without leak recurrence. No meningitis, permanent morbidity or mortality was observed after stenting. Compared to 18 controls, cases had significantly less recurrence (P = 0.03), and a trend for less adjunctive treatment for IIH (P = 0.06).

CONCLUSIONS

Our study suggests that stenting might be a valid option for prevention of sCSF-leak recurrences after repair in patients with intracranial venous sinus stenosis.

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.

Spinal CSF-Venous Fistulas in Morbidly and Super Obese Patients with Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE

Spinal CSF-venous fistulas are increasingly recognized as the cause of spontaneous intracranial hypotension. Here, we describe the challenges in the care of patients with CSF-venous fistulas who are morbidly or super obese.

MATERIALS AND METHODS

A review was undertaken of all patients with spontaneous intracranial hypotension and a body mass index of >40 who underwent digital subtraction myelography in the lateral decubitus position to look for CSF-venous fistulas.

RESULTS

Eight patients with spontaneous intracranial hypotension with a body mass index  of >40 underwent lateral decubitus digital subtraction myelography. The mean age of these 5 women and 3 men was 53 years (range, 45 to 68 years). Six patients were morbidly obese (body mass indexes = 40.2, 40.6, 41, 41.8, 45.4, and 46.9), and 2 were super obese (body mass indexes = 53.7 and 56.3). Lumbar puncture showed an elevated opening pressure in 5 patients (26.5-47 cm H₂O). The combination of an elevated opening pressure and normal conventional spine imaging findings resulted in a misdiagnosis (midbrain glioma and demyelinating disease, respectively) in 2 patients. Prior treatment included surgical nerve root ligation for suspected CSF-venous fistula in 3 patients. Digital subtraction myelography demonstrated a CSF-venous fistula in 6 patients (75%). Rebound high-pressure headache occurred in all 6 patients following surgical ligation of the fistula, and papilledema developed in 3.

CONCLUSIONS

In our series, opening pressure was generally elevated in patients with morbid or super obesity. The yield of identifying CSF-venous fistulas with digital subtraction myelography in this patient population can approach that of the nonobese patient population. These patients may be at higher risk of developing rebound high-pressure headaches and papilledema.

The relationship between spontaneous cerebrospinal fluid leak and idiopathic intracranial hypertension

Surgical treatment of spontaneous cerebrospinal fluid (CSF) leak is now performed by ENT surgeons, endonasal endoscopy being preferred to craniotomy as less invasive. However, it is often the symptom of underlying idiopathic intracranial hypertension, which lies outside the traditional sphere of ENT competence. Surgery is a necessary step, but should not obscure the need to treat the underlying pathology. This treatment is complex, and requires multidisciplinary team-work between otorhinolaryngologist, ophthalmologist, neurologist, neurosurgeon, radiologist, dietician, endocrinologist and psychotherapist. The present update details this multidisciplinary management to which the ENT surgeons must be attentive before and after spontaneous CSF leak repair.

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.

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.

Spontaneous Skull Base Cerebrospinal Fluid Leaks and Their Relationship to Idiopathic Intracranial Hypertension

Background

The association between spontaneous skull base cerebrospinal fluid (CSF) leaks and idiopathic intracranial hypertension (IIH) has been suggested, but its significance remains unclear.

Objective

To estimate the prevalence of IIH in spontaneous skull base CSF leak patients.

Methods

Systematic collection of demographics, neuro-ophthalmic and magnetic resonance imaging evaluation of spontaneous skull base CSF leak patients seen pre- and post-leak repair in one neuro-ophthalmology service. Patients with preexisting IIH were diagnosed with definite IIH if adequate documentation was provided; otherwise, they were categorized with presumed IIH. Classic radiographic signs of intracranial hypertension and bilateral transverse venous sinus stenosis were recorded.

Results

Thirty six patients were included (age [interquartile range]: 50 [45;54] years; 94% women; body mass index: 36.8 [30.5;39.9] kg/m2), among whom six (16.7%, [95% confidence interval, CI]: [6.4;32.8]) had a preexisting diagnosis of definite or presumed IIH. Of the remaining 30 patients, four (13.3%, 95%CI: [3.8;30.7]) had optic nerve head changes suggesting previously undiagnosed IIH, while one was newly diagnosed with definite IIH at initial consultation. One out of 29 patients with normal findings of the optic nerve head at presentation developed new onset papilledema following surgery (3.4%, 95%CI: [0.1;17.8]) and was ultimately diagnosed with definite IIH. Overall, the prevalence of definite IIH was 19.4% (95%CI: [8.2;36.0]).

Conclusion

Striking demographic overlap exists between IIH patients and those with spontaneous CSF leak. Definite IIH was present in approximately 20% of our patients. However, its true prevalence is likely higher than identified by using classic criteria. We therefore hypothesize that an active CSF leak serves as an auto-diversion for CSF, thereby “treating” the intracranial hypertension and eliminating characteristic signs and symptoms at initial presentation.

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.

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.

Spontaneous cerebrospinal fluid leak and idiopathic intracranial hypertension

PURPOSE OF REVIEW

To review the most recent literature on the relationship of spontaneous cerebrospinal fluid (CSF) leak with idiopathic intracranial hypertension (IIH) and considerations in management of these conditions.

RECENT FINDINGS

A link has been proposed between spontaneous CSF leak and IIH based on similar demographics, radiologic, and clinical findings in these patients, and on a plausible mechanism of skull base erosion in the setting of high CSF pressure over time. IIH patients with CSF leak may not present with classic IIH signs and symptoms as the leak can alleviate excess pressure; however, they may develop these after a leak is repaired. There may also be a higher risk of leak recurrence if intracranial hypertension is not treated postoperatively.

SUMMARY

A growing body of evidence supports an association between IIH and spontaneous CSF leak. However, this relationship is still not fully elucidated, and there is no current agreement on how to incorporate screening, management, or counseling guidelines for CSF leak into the care of IIH patients. There are also no specific guidelines for evaluation/management of IIH in patients with spontaneous CSF leak. Further interdisciplinary research is needed to explore this connection and to establish screening, evaluation, and management guidelines.

Impact of Obesity and Obstructive Sleep Apnea in Lateral Skull Base Cerebrospinal Fluid Leak Repair

OBJECTIVE

To investigate the prevalence and impact of obstructive sleep apnea (OSA) and obesity in lateral skull base cerebrospinal fluid leak repair (LSBR) of various etiologies.

METHODS

Retrospective case review at a tertiary skull base center was conducted of consecutive adults undergoing LSBR via transmastoid, middle cranial fossa, or combined approach between 2013-2018. The following data were collected: demographics, comorbidities, radiology and intraoperative findings, and surgical outcomes including complications and need for revision surgery or shunt placement. Patients with incomplete data or leaks following skull base surgery, trauma or chronic ear disease were excluded.

RESULTS

Ninety-four patients (67.4% female, mean age 53.5 ± 12.9 years) underwent repair for spontaneous (sCSFL, 44%) and other etiology (nsCSFL) leaks. nsCSFL served as a comparison group consisting of leaks status-post lateral skull base surgery, temporal bone fractures, and chronic ear disease. Class III obesity (P = .02), OSA (P = .03), and imaging findings of empty sella (OR = 3.32, P = .02), and skull base thinning including contralateral tegmen thinning (31%, OR = 4.3, P = .02), arachnoid granulations (26%, OR = 4.35, P = .02), and superior canal dehiscence (15.8%, OR = 8.57, P = .04) were more common in sCSFL. Four patients (4.2%) required surgical revision for recurrence, and another four (4.2%) resolved with shunting. Evidence of elevated intracranial hypertension was present in nine patients with sCSF leaks and was predictive of need for revision or shunt procedures (P < .01).

CONCLUSION

Obesity, OSA, and imaging consistent with elevated intracranial pressures were more common among patients with sCSFL. Elevated intracranial pressure predicted outcomes following multilayer repair of spontaneous CSF leaks LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2234-2240, 2020.

Asymptomatic Versus Symptomatic Idiopathic Intracranial Hypertension in Children

BACKGROUND

Idiopathic intracranial hypertension is a rare neurologic condition characterized by elevated intracranial pressure with normal cerebrospinal fluid analysis and neuroimaging. A subset of pediatric idiopathic intracranial hypertension patients are coincidentally found to have papilledema and elevated intracranial pressure without symptoms (eg, headache, visual blurring, tinnitus). This study aims to investigate the features of asymptomatic pediatric idiopathic intracranial hypertension.

METHODS

Retrospective case-control study of patients aged 0 to 18 years who received idiopathic intracranial hypertension diagnosis from 2005 to 2016. Subjects were included if they met established diagnostic criteria for idiopathic intracranial hypertension diagnosis. Subjects were classified as symptomatic if they presented with 1 symptom related to elevated intracranial pressure, and asymptomatic if no symptoms were present. Statistical analysis was performed to compare the 2 groups.

RESULTS

12 (22.6%) of 53 pediatric idiopathic intracranial hypertension subjects were asymptomatic. Compared to symptomatic idiopathic intracranial hypertension, asymptomatic idiopathic intracranial hypertension had younger age of onset, lower initial opening pressure on lumbar puncture, lower optic nerve edema grades bilaterally, lower likelihood of globe flattening on magnetic resonance imaging (MRI), and smaller required dose of acetazolamide for resolution of papilledema (all P < .05).

CONCLUSION

Asymptomatic idiopathic intracranial hypertension is common among pediatric patients with papilledema and is an important disease entity that requires special clinical management. It may exist as a milder version of idiopathic intracranial hypertension that occurs in younger children, or as a precursor state that later evolves into symptomatic disease.

Postoperative management of patients with spontaneous cerebrospinal fluid leak

PURPOSE OF REVIEW

To explore key management principles and outcomes following surgical intervention for spontaneous CSF leaks of the lateral skull base.

RECENT FINDINGS

Outcomes following surgery for spontaneous CSF leaks of the lateral skull base depend on the surgical approach utilized. The approach reported most frequently in the literature is currently the middle fossa approach. Mean leak recurrence rates, regardless of approach, were approximately 6%. The lowest leak recurrence rates were associated with the combined middle cranial fossa-transmastoid approach. A multilayer closure was employed in all of the reviewed investigations, but the choice of reconstructive material did not significantly affect outcomes. Direct surgical complications rates, overall, were low at less than 2%. Meningitis, intracranial hemorrhage, and perioperative seizure activity were only rarely encountered. A concomitant diagnosis of idiopathic intracranial hypertension was found to be associated with increased rates of leak recurrence and sequential leak development at other skull base sites.

SUMMARY

Postoperative management of patients with spontaneous CSF leaks of the lateral skull base has unique challenges. Observation of key treatment principles can lead to good outcomes and limit morbidity. A high index of suspicion should exist for concomitant idiopathic intracranial hypertension.

Headaches Due to Low and High Intracranial Pressure

PURPOSE OF REVIEW

Headache disorders attributed to low and high intracranial pressure are commonly encountered in specialty headache practices and may occur more frequently than realized. While the headaches resulting from intracranial pressure disorders have what are conventionally thought of as defining characteristics, a substantial minority of patients do not manifest the "typical" features. Moreover, patients with intracranial pressure disorders may also have a preexisting primary headache disorder. Heightening the complexity of the presentation, the headaches of intracranial pressure disorders can resemble the phenotype of a primary disorder. Lastly, patients with so-called intracranial "hypotension" often have normal CSF pressure and neuroimaging studies. Thus, a high index of suspicion is needed. The published literature has inherent bias as many types of specialists evaluate and treat these conditions. This article reviews the key points to emphasize the history, examination, and laboratory evaluation of patients with intracranial pressure disorders from a neurologist's perspective.

RECENT FINDINGS

Lumbar puncture opening pressure in patients with spontaneous intracranial hypotension was low enough to meet diagnostic criteria (≤60 mm CSF) in only 34% of patients in one study. Most patients had an opening pressure in the low normal to normal range, and 5% had an opening pressure of 200 mm CSF or more. Diskogenic microspurs are a common cause of this syndrome. The Idiopathic Intracranial Hypertension Treatment Trial found that most participants had a headache phenotype resembling migraine or tension-type headache. No "typical" or characteristic headache phenotype was found, and headache-related disability was severe at baseline. Headache disability did not correlate with the lumbar puncture opening pressure at baseline or at the 6-month primary outcome period. Although participants who were randomly assigned to acetazolamide had a lower mean CSF opening pressure at 6 months, headache disability in that group was similar to the group who received placebo.

SUMMARY

Significant overlap is seen in the symptoms of high and low CSF pressure disorders and in those of primary headache disorders. Neurologists are frequently challenged by patients with headaches who lack the typical clinical signs or imaging features of the pseudotumor cerebri syndrome or spontaneous intracranial hypotension. Even when characteristic symptoms and signs are initially present, the typical features of both syndromes tend to lessen or resolve over time; consider these diagnoses in patients with long-standing "chronic migraine" who do not improve with conventional headache treatment. While the diagnostic criteria for pseudotumor cerebri syndrome accurately identify most patients with the disorder, at least 25% of patients with spontaneous intracranial hypotension have normal imaging and over half have a normal lumbar puncture opening pressure. Detailed history taking will often give clues that suggest a CSF pressure disorder. That said, misdiagnosis can lead to significant patient morbidity and inappropriate therapy.

Surgical Outcomes and Postoperative Management in Spontaneous Cerebrospinal Fluid Rhinorrhea

Background  The etiology of spontaneous cerebrospinal fluid (CSF) rhinorrhea remains unknown, though emerging evidence suggests that this likely represents a variant of idiopathic intracranial hypertension. Long-term success rates for repair and postoperative management strategies remain variable. Methods  Retrospective review of patients undergoing surgical management of spontaneous CSF rhinorrhea was conducted over a 5-year period. Analysis was performed to correlate recurrence with demographics and perioperative variables. Lumbar puncture usage and neuro-ophthalmological examinations in clinical management were also assessed. Results  Forty-eight patients were included in the study. The mean age was 51.4 years with 94% females. Leaks were most commonly located in the sphenoid (43.8%) and cribriform region (33.3%). The most common findings on magnetic resonance imaging were empty sella (48%) and Meckel's cave diverticula (24%). Nine patients (18.8%) had recurrent CSF leaks. Six occurred >1 month postoperatively. Three had repeat endoscopic repairs, two received ventriculoperitoneal shunts, and one was managed with a lumbar drain, with overall success rate of 93.8%. Acetazolamide was utilized in 19 cases (39.6%) postoperatively. Overall, 59% of patients had elevated opening pressures on postoperative lumbar puncture ( n  = 32). Neuro-ophthalmology evaluated 28 patients; 25% had visual field deficits, and 7.1% had papilledema. Conclusions  Management of spontaneous CSF leaks remains a significant challenge. Endoscopic repair is successful in most patients with little morbidity; however, postoperative management remains inconsistent, and further studies are warranted to establish consensus on post-surgical care. The association with elevated intracranial pressure and visual field deficits/papilledema suggests opening pressures, and neuro-ophthalmologic evaluation should be considered in the treatment algorithm.

Spontaneous Cerebrospinal Fluid Rhinorrhea: Association with Body Weight and Imaging Data

Objective  Spontaneous cerebrospinal fluid rhinorrhea (SCSFR) might be the only clinical manifestation of idiopathic intracranial hypertension (IIH), which has been historically related to overweight. Our goal was to search for an association between SCSFR and increased body weight on the one hand and SCSFR and imaging findings suggestive of IIH on the other hand. Materials and Methods  We retrospectively collected clinical and radiological data of patients operated on endoscopically for SCSFR in our institution from 1993 to 2013. Analyzed factors were body mass index (BMI), extended sphenoid sinus pneumatization on computed tomography, and empty sella and distention of the optic nerve sheath on magnetic resonance imaging. Results  There were 15 patients: 8 females/7 males; mean age 50 years. Primary surgical success rate was 86.7%. Regarding body weight, 80% were overweight (BMI ≥ 25) versus 32% in the French general population ( p  < 0.001). Among patients with SCSFR, 20% were obese (BMI ≥ 30) versus 15% in French individuals without SCSFR ( p  = 0.483). Increased pneumatization of sphenoid sinuses was observed in 92.9 versus 27.5% in the general population ( p  < 0.0001). Empty sella was found in 46.2 versus 3% in the general population ( p  < 0.00001). Dilation of the optic nerve sheath was observed in 46.2 versus 15% in the general population ( p  < 0.01). Conclusion  We found statistically significant associations between SCSFR and overweight, increased pneumatization of sphenoid sinuses, empty sella, and dilation of optic nerve sheath, but not with obesity, which did not have any additional impact of CSF leak than did overweight.

Intervention for elevated intracranial pressure improves success rate after repair of spontaneous cerebrospinal fluid leaks

OBJECTIVES/HYPOTHESIS

Spontaneous cerebrospinal fluid (CSF) leaks are associated with increased intracranial pressure (ICP) and considered a manifestation of idiopathic intracranial hypertension. Although postoperative acetazolamide and placement of CSF shunt systems are considered valuable interventions for elevated ICP, the impact on recurrence rate remains unclear. The objective of this study was to systematically review evidence from reported literature to evaluate whether postoperative ICP management reduces recurrence rates after primary endoscopic repair.

STUDY DESIGN

Prospective case series and systematic review.

METHODS

Demographics, defect location, success rates, and ICP management in spontaneous CSF leak patients were prospectively collected over 8 years. A search was also conducted in PubMed to identify studies reporting cases of spontaneous CSF rhinorrhea.

RESULTS

Fifty-six articles with nonduplicated data were identified and combined with a prospective series of 108 patients for a total of 679 patients treated for spontaneous CSF rhinorrhea. Average age was 50.4 years with 77% female. Average body mass index was 35.8 kg/m² . Defects were most commonly located in the sphenoid sinus (n = 334) followed by the ethmoid (n = 318) and the frontal sinus (n = 46). Successful primary repair was 92.82% in patient cohorts where ICP evaluation and intervention with acetazolamide or CSF shunt systems was performed, but was significantly decreased to 81.87% in series with no active management of elevated ICP (P < .001).

CONCLUSIONS

Evaluation and intervention for elevated ICP in spontaneous CSF leaks is associated with significantly improved success rates following primary endoscopic repair.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2011-2016, 2017.

Surgical repair of spontaneous cerebrospinal fluid (CSF) leaks: A systematic review

Objectives

To review the safety and efficacy of surgical management for spontaneous cerebrospinal fluid (CSF) leaks of the anterior and lateral skull base.

Data Sources

A systematic review of English articles using MEDLINE.

Review Methods

Search terms included spontaneous, CSF, cerebrospinal fluid, endoscopic, middle fossa, transmastoid, leak, rhinorrhea. Independent extraction of articles by 3 authors.

Results

Patients with spontaneous CSF leaks are often obese (average BMI of 38 kg/m²) and female (72%). Many patients also have obstructive sleep apnea (∼45%) and many have elevated intracranial pressure when measured by lumbar puncture. In addition to thinning of the skull base, radiographic studies also demonstrate cortical bone thinning. Endoscopic surgical repair of anterior skull base leaks and middle cranial fossa (MCF) approach for repair of lateral skull base leaks are safe and effective with an average short‐term failure rate of 9% and 6.5%, respectively. Long‐term failure rates are low. One randomized trial failed to show improved success of anterior leak repairs with the use of a lumbar drain (LD) (95% with vs. 92% without; P = 0.2). In a large retrospective cohort of MCF lateral skull base repairs, perioperative LD use was not necessary in >94% of patients.

Conclusions

Spontaneous CSF leaks are associated with female gender, obesity, increased intracranial hypertension, and obstructive sleep apnea. Endoscopic repair of anterior skull base leaks and MCF or transmastoid approaches for lateral skull base leaks have a high success rate of repair. In most cases, intraoperative placement of lumbar drain did not appear to result in improved success rates for either anterior or lateral skull base leaks.

Level of Evidence

2a, Systematic Review.

Idiopathic intracranial hypertension: Contemporary review and implications for the otolaryngologist

OBJECTIVES

1) Review controversies pertaining to the pathophysiology, diagnosis, and treatment of idiopathic intracranial hypertension. 2) Discuss the evolving role of otolaryngologists in managing this disease and related disorders.

DATA SOURCES

Primary literature review, Centers for Disease Control and Prevention website, International Classification of Headache Disorders, Second Edition.

METHODS

A comprehensive review of the primary literature was performed from 1990 to 2016 utilizing keywords idiopathic intracranial hypertension, pseudotumor cerebri, benign intracranial hypertension, spontaneous cerebrospinal fluid leak, and encephalocele. Articles were included at the discretion of the authors based on novel and/or historical contributions to the literature.

RESULTS

The incidence of idiopathic intracranial hypertension is increasing along with the obesity epidemic. Undiagnosed patients may present to otolaryngologists with pulsatile tinnitus, dizziness, sleep apnea, and spontaneous cerebrospinal fluid leaks. Although diagnosis is predicated upon imaging findings and lumbar puncture, radiographic signs including empty sella, optic nerve dilation, and globe flattening may suggest the diagnosis. The most effective intervention is weight loss combined with acetazolamide. Surgery is reserved for severe or refractory symptoms and can be highly morbid. Otolaryngologists are increasingly responsible for managing a number of secondary disorders including cerebrospinal fluid rhinorrhea and otorrhea. Failure to manage intracranial hypertension may lead to adverse surgical outcomes.

CONCLUSIONS

The knowledge base for idiopathic intracranial hypertension has greatly expanded over the past 25 years. This disease is associated with a number of conditions directly relevant to otolaryngologists. A keen understanding of this disorder and its management may optimize outcomes in a growing number of patients. Laryngoscope, 128:248-256, 2018.

Lower airway disease and pituitary surgery: Is there an association with postoperative cerebrospinal fluid leak?

OBJECTIVES/HYPOTHESIS

To explore the relationship between lower airway disease and postoperative cerebrospinal fluid (CSF) rhinorrhea among patients undergoing pituitary surgery STUDY DESIGN: Retrospective review.

METHODS

A retrospective review of the Healthcare Cost and Utilization Project's 2013 National Inpatient Sample was conducted to characterize the hospital stay and surgical outcomes of patients undergoing pituitary surgery. Patients with lower airway disease (including chronic obstructive pulmonary disease and asthma) were compared to a disease-free population identifying demographics and complications over-represented in the lower airway group.

RESULTS

The majority of hypophysectomies (92.1%) were performed via a transsphenoidal approach. Among transsphenoidal patients, individuals with asthma (92.8% of the lower airway disease cohort) harbored a greater postoperative CSF leak rate (4.7% vs. 2.7%, P = .022), and were more likely to develop postoperative diabetes insipidus (6.2% vs. 4.1%, P = .024) and neurological complications (13.0% vs. 9.6%, P = .010) when compared to a lower airway disease-free cohort. Patients with CSF rhinorrhea had longer lengths of stay (7.8 days vs. 4.5 days, P < .001) and higher discharge costs ($148,309 vs. $76,246, P < .001). A binary logistic regression model identified having asthma (P = .042), being female (P = .011), and having gastroesophageal reflux disease (P = .006) as independent predictors of postoperative CSF rhinorrhea.

CONCLUSIONS

Several patient comorbidities including asthma are associated with a greater risk of postoperative CSF rhinorrhea. Perioperative lower airway assessment and disease control may potentially decrease one's risk of this complication, although further inquiry is urgently needed to identify optimal preventive strategies.

LEVEL OF EVIDENCE

2c. Laryngoscope, 127:1543-1550, 2017.

Enlargement of Meckel's cave in patients with spontaneous cerebrospinal fluid leaks

BACKGROUND

Spontaneous cerebrospinal fluid (CSF) leaks have imaging findings consistent with chronically elevated intracranial pressure, such as empty sella. Meckel's cave is a CSF-filled space that houses the trigeminal ganglion at the cranial base. Our objective in this study was to evaluate "dilated" Meckel's cave as a radiologic sign in patients with elevated intracranial pressure spontaneous CSF leaks and compare the dimensions with those from a control cohort.

METHODS

Meckel's cave dimensions were measured in patients with spontaneous CSF leaks and documented elevated intracranial pressure. A control group of subjects who underwent magnetic resonance imagine (MRI) scans for unrelated diagnoses were also evaluated. Subjects were included only if suitable MRIs with T2-weighted sequences in the axial plane were available.

RESULTS

Sixty-three patients with spontaneous CSF leaks and 91 normal control patients were included in the study. There was significant (p < 0.05) enlargement in all measured dimensions (length and width) for the spontaneous CSF leak group. When evaluating area, spontaneous CSF leak subjects again showed significant enlargement compared with controls (0.81 ± 0.35 cm² vs 0.52 ± 0.15 cm² ; p < 0.0001). Average intracranial pressure measurements were 25.9 ± 9.0 cmH₂ O.

CONCLUSION

Patients with spontaneous CSF leaks have evidence of enlarged Meckel's caves. Evaluation of Meckel's cave dimensions should be included in preoperative imaging assessment as an additional indicator of chronically elevated intracranial pressure.

The role of ICP monitoring in patients with persistent cerebrospinal fluid leak following spinal surgery: a case series

BACKGROUND

Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission.

METHODS

A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome.

RESULTS

Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12-month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8  ± 12.9 days.

CONCLUSIONS

Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.