The evolution of presenting signs and symptoms of lateral skull base cerebrospinal fluid leaks

An algorithm for the surgical approach to spontaneous temporal bone CSF leak

OBJECTIVE

To suggest a comprehensive algorithm for the surgical approach for correcting of sources of temporal bone CSF leaks.

METHODS

A case series for patients operated in a single academic tertiary referral center between 2011 and 4.2022. Included in the study were 46 patients, 5 of whom had a bilateral problem, resulting in 51 pathologic temporal bones. The presentation was an active CSF leak (38 patients) or bacterial otogenic meningitis (8 patients). Follow up ranged from 8 months to 5 years.

RESULTS

Of the 42 ears operated via the default middle fossa approach, 37 were successful (88 %) in controlling CSF leak. None had intracranial complications or sensorineural hearing loss. Location, number and size of the defects, hearing status, associated superior semicircular canal dehiscence, additional intra-temporal or intra-cranial pathologies may indicate a transmastoid approach. Of the six ears that had a canal wall up mastoidectomy as a primary procedure, one required revision due to ongoing CSF leak. Five revision cases and three primary cases were effectively sealed with a subtotal petrosectomy and obliteration. One was lost to follow-up. Hearing was reconstructed with bone-anchored hearing implants in 6 out of these 8 ears.

CONCLUSIONS

The middle fossa approach could be used as a default approach for sealing TD. There are a number of indications for transmastoid approaches in both primary and revision cases. Obliteration of the ear was used in all revision cases. The suggested algorithm can help in planning surgery for temporal bone CSF leaks or a history of otogenic meningitis.

Management of Fallopian Canal Spontaneous CSF Leaks, Implications of Elevated Intracranial Pressure: Case Report and Systematic Review of the Literature

OBJECTIVES

Describe the diagnosis and management of a spontaneous cerebrospinal fluid leak (sCSF-L) through the facial nerve fallopian canal and determine the role of intracranial hypertension (IH).

STUDY DESIGN

Retrospective case study and systematic review of the literature.

METHODS

Reviewed patient characteristics, radiographic findings, and management of the facial nerve canal CSF leak and postoperative IH. Conducted systematic literature review according to the PRISMA guidelines for surgical management and rates of IH.

RESULTS

A 50-year-old female with bilateral tegmen defects and temporal encephaloceles underwent left middle cranial fossa (MCF) repair. Intraoperative CSF egressed from the temporal bone tegmen defects. Facial nerve decompression revealed CSF leak from the labyrinthine segment. A nonocclusive temporalis muscle plug was placed in the fallopian canal, and tegmen repair was completed with bone cement. A ventriculoperitoneal shunt was placed for IH. Postoperative facial nerve function and hearing were normal. A total of 20 studies met inclusion criteria with a total of 25 unique patients. Of 13 total adult cases of fallopian canal CSF leak, there is a 46% recurrence rate, and 86% of patients had documented IH when tested.

CONCLUSIONS

Fallopian canal CSF leaks are rare and challenging to manage. Assessment of intracranial hypertension and CSF diversion is recommended along with MCF skull base repair to preserve facial nerve function and conductive hearing.

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.

An Elusive Diagnosis: Delays in Treatment and Opportunities for Improvement in Temporal Encephalocele and CSF Leak

Objective

Symptoms of temporal encephalocele or cerebrospinal fluid (CSF) leak causing middle ear effusion or otorrhea can be nonspecific and mistaken for other common diagnoses, leading to delays in diagnosis, failed treatments, and a risk of meningitis. This study sought to investigate the association between symptomatology and time to definitive surgical management.

Study Design

Retrospective cohort.

Setting

Single tertiary care academic medical center.

Patients

Adults treated surgically for temporal encephalocele or CSF leak. Revision cases were excluded.

Interventions

Chart review was performed to identify pertinent symptoms at presentation. Multivariable regression was performed to analyze the association between symptoms and time to definitive management.

Main Outcome Measures

Otologic and related symptoms present prior to middle cranial fossa (MCF). Time between symptom onset and surgical treatment.

Results

Thirty-four patients had symptoms present a median of 15.5 months (interquartile range, 8-35 months; range, 1 month to 12 years) prior to surgery. The most common symptoms were subjective hearing loss in the affected ear (76.5%) and aural fullness (73.5%). Otorrhea was present in 55.9%, and 42.9% had a history of otorrhea after myringotomy with or without tube insertion. Meningitis occurred in 5 patients (14.7%). Only the absence of otalgia was statistically significantly associated with decreased time between symptoms onset and surgery (P = 0.01).

Conclusions

Encephalocele and CSF leak were most commonly associated with aural fullness and hearing loss. Medical treatment for presumed Eustachian tube dysfunction or chronic ear disease were commonly observed. Patients had symptoms for a median of almost 1 and a half years prior to surgical management.

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.

Comparison of Outcomes of Surgical Repair of Spontaneous Temporal Bone CSF Leaks and Encephaloceles Using Bone Cement and Autologous Material

OBJECTIVE

To compare outcomes transmastoid repair of spontaneous middle fossa cerebrospinal fluid (CSF) leak using only bone cement (BC) versus only autologous material (AM) or combined materials (CM) with both bone cement and autologous material.

STUDY DESIGN

Retrospective Chart Review.

SETTING

Tertiary Care Hospital.

PATIENTS

Forty-three adult patients undergoing transmastoid repair of spontaneous middle fossa CSF leak between 2014 and 2020 (BC:12, AM:15, CR:16).

INTERVENTIONS

Cortical mastoidectomy, identification of defect, and repair with BC (Cranios® hydroxyapatite), AM (local bone, fascia, fat, and/or cartilage), or CM (Cranios® combined with autologous materials).

MAIN OUTCOME MEASURES

Successful repair without recurrent CSF leak or encephalocele throughout follow up.

RESULTS

Fifty-one percent of subjects were female. Mean age at repair was 58.6 years (SD 10.9). Mean BMI was 35.4 (SD 7.6; BC:36.3, AM:36.5, CM:33.6). Forty (93%) patients had successful repair without known recurrent CSF leak or encephalocele since surgery (BC:11, 91.6%; AM:14, 93.3%; CM:15, 93.8%; p = 0.49) over a mean length of follow up of 49.6 months (BC: 37.9, AM: 59.2, CR: 49.5). The difference in mean operative time amongst the groups was faster for patients using bone cement (BC: 100.2 min, AM: 182.8, CM: 133.2; p < 0.00001).

CONCLUSIONS

BC, AM, and CM techniques each demonstrate effective and sustained means of repair for middle fossa CSF leak and encephalocele, even in the presence of multiple defects. Use of isolated BC offers a significant decrease in operative time with a noninferior outcome. Active CSF leak at the time of surgery is associated with increased risk of recurrence.

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.

Cerebrospinal Fluid Leaks From the Lateral Ventricle: A Case Series

OBJECTIVES

Describe the diagnosis and management of lateral skull base (LSB) cerebrospinal fluid (CSF) leaks originating from the lateral ventricle.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral academic center.

PATIENTS

Patients with CSF leaks with direct communication to the lateral ventricle on preoperative imaging.

INTERVENTION

Surgical repair via the middle cranial fossa (MCF) approach.

MAIN OUTCOME MEASURES

CSF leak patient characteristics (age, sex, body mass index [BMI]) and postoperative course (complications and CSF leak resolution) were collected.

RESULTS

Three patients had CSF leaks from the lateral ventricle and all patients demonstrated encephalomalacia of the temporal lobe on preoperative imaging. Encephalomalacia resulted from trauma in one case (age 5) and neurodegeneration in two cases (age 77 and 84). BMI ranged from 16.3 to 26.6 mg/kg2 and follow-up ranged from 4 to 21 months. Two patients presented with preoperative meningitis and all patients had resolution of CSF leaks after MCF repair. With the exception of the higher rate of meningitis, patient presentations did not differ from other spontaneous CSF leaks through middle fossa defects. There were no minor or major postoperative complications.

CONCLUSIONS

CSF leaks from the lateral ventricle represent a rare subset of LSB CSF leaks and can occur in non-obese patients secondary to temporal lobe encephalomalacia. The MCF approach allows for repair of the dura and skull base in this cohort of patients with high-flow CSF leaks and loss of brain parenchyma.

Calvarium Thinning in Patients with Spontaneous Cerebrospinal Fluid Leaks of the Anterior Skull Base

OBJECTIVES/HYPOTHESIS

Patients with spontaneous cerebrospinal fluid leaks (sCSF-L) of the temporal bone have isolated calvarial and skull base thinning that is independent of obesity. This study determines if anterior skull base (ASB) sCSF-L patients also have calvarial thinning.

STUDY DESIGN

Retrospective Cohort Study.

METHODS

This was a retrospective cohort study of ASB sCSF-L patients compared to nonobese (body mass index [BMI] < 30 kg/m² ) and obese (BMI ≥ 30) control groups. Twenty-one patients in the ASB sCSF-L group and 25 patients in each control group were included. Calvarium and extracranial zygoma thicknesses were measured bilaterally with blinded, standardized, volumetric analysis.

RESULTS

ASB sCSF-L patients had a mean (SD) age of 50.43 (10.19) years, an average (SD) BMI of 38.81 (8.92) kg/m² , and most were female (85.71%). The calvarium in patients with ASB sCSF-L was significantly thinner than the nonobese (2.55 mm [0.77] vs. 2.97 [0.67] mm; P = .006; 95% confidence intervals [CI], 0.12-0.30; Cohen d, 0.58) and obese control groups (2.55 [0.77] vs. 2.92 [0.76] mm; P = .02; 95% CI, 0.05-0.34; Cohen d, 0.66). The calvarium thickness of the nonobese patients was not significantly different from the obese patient controls (2.97 [0.67] vs. 2.92 [0.76] mm, P = .9). The extracranial zygoma was not significantly different among the groups (analysis of variance, P = .33).

CONCLUSIONS

ASB sCSF-L patients have isolated calvarial thinning that is independent of obesity. Like lateral skull base sCSF-L patients, these data suggest that the additional obesity-associated intracranial process contributes to skull thinning.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1271-1276, 2021.