D. Jay McCracken

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Hearing Preservation Outcomes in Patients With Sporadic Vestibular Schwannomas

Abstract Please see the full‐text version of this guideline (https://www.cns.org/guidelines/guidelines‐management‐patients‐vestibular‐schwannoma/chapter_3) for the target population of each recommendation listed below. STEREOTACTIC RADIOSURGERY Question 1: What is the overall probability of maintaining serviceable hearing following stereotactic radiosurgery utilizing modern dose planning, at 2, 5, and 10 yr following treatment? Recommendation: Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is moderately high probability (>50%‐75%) of hearing preservation at 2 yr, moderately high probability (>50%‐75%) of hearing preservation at 5 yr, and moderately low probability (>25%‐50%) of hearing preservation at 10 yr. Question 2: Among patients with AAO‐HNS (American Academy of Otolaryngology‐Head and Neck Surgery hearing classification) class A or GR (Gardner‐Robertson hearing classification) grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing following stereotactic radiosurgery, utilizing modern dose planning, at 2, 5, and 10 yr following treatment? Recommendation: Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is a high probability (>75%‐100%) of hearing preservation at 2 yr, moderately high probability (>50%‐75%) of hearing preservation at 5 yr, and moderately low probability (>25%‐50%) of hearing preservation at 10 yr. Question 3: What patient‐ and tumor‐related factors influence progression to nonserviceable hearing following stereotactic radiosurgery using ≤13 Gy to the tumor margin? Recommendation: Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled regarding the probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut‐points reported, smaller tumor size, marginal tumor dose ≤12 Gy, and cochlear dose ≤4 Gy. Age and sex are not strong predictors of hearing preservation outcome. MICROSURGERY Question 4 What is the overall probability of maintaining serviceable hearing following microsurgical resection of small to medium‐sized sporadic vestibular schwannomas early after surgery, at 2, 5, and 10 yr following treatment? Recommendation Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled that there is a moderately low probability (>25%‐50%) of hearing preservation immediately following surgery, moderately low probability (>25%‐50%) of hearing preservation at 2 yr, moderately low probability (>25%‐50%) of hearing preservation at 5 yr, and moderately low probability (>25%‐50%) of hearing preservation at 10 yr. Question 5 Among patients with AAO‐HNS class A or GR grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing following microsurgical resection of small to medium‐sized sporadic vestibular schwannomas early after surgery, at 2, 5, and 10 yr following treatment? Recommendation Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled that there is a moderately high probability (>50%‐75%) of hearing preservation immediately following surgery, moderately high probability (>50%‐75%) of hearing preservation at 2 yr, moderately high probability (>50%‐75%) of hearing preservation at 5 yr, and moderately low probability (>25%‐50%) of hearing preservation at 10 yr. Question 6 What patient‐ and tumor‐related factors influence progression to nonserviceable hearing following microsurgical resection of small to medium‐sized sporadic vestibular schwannomas? Recommendation Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled regarding the probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut‐points reported, smaller tumor size commonly less than 1 cm, and presence of a distal internal auditory canal cerebrospinal fluid fundal cap. Age and sex are not strong predictors of hearing preservation outcome. CONSERVATIVE OBSERVATION Question 7 What is the overall probability of maintaining serviceable hearing with conservative observation of vestibular schwannomas at 2, 5, and 10 yr following diagnosis? Recommendation Level 3: Individuals who meet these criteria and are considering observation should be counseled that there is a high probability (>75%‐100%) of hearing preservation at 2 yr, moderately high probability (>50%‐75%) of hearing preservation at 5 yr, and moderately low probability (>25%‐50%) of hearing preservation at 10 yr. Question 8 Among patients with AAO‐HNS class A or GR grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing with conservative observation at 2 and 5 yr following diagnosis? Recommendation Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is a high probability (>75%‐100%) of hearing preservation at 2 yr, and moderately high probability (>50%‐75%) of hearing preservation at 5 yr. Insufficient data were available to determine the probability of hearing preservation at 10 yr for this population subset. Question 9 What patient and tumor‐related factors influence progression to nonserviceable hearing during conservative observation? Recommendation Level 3: Individuals who meet these criteria and are considering observation should be counseled regarding probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut‐points reported, as well as nongrowth of the tumor. Tumor size at the time of diagnosis, age, and sex do not predict future development of nonserviceable hearing during observation. The full guideline can be found at: https://www.cns.org/guidelines/guidelines‐manage‐ment‐patients‐vestibular‐schwannoma/chapter_3.

Comparison Between CTA and Digital Subtraction Angiography in the Diagnosis of Ruptured Aneurysms

BACKGROUND: Computerized tomography angiography (CTA) is commonly used to diagnose ruptured cerebral aneurysms with sensitivities reported as high as 97% to 100%. Studies validating CTA accuracy in the setting of subarachnoid hemorrhage (SAH) are scarce and limited by small sample sizes. OBJECTIVE: To evaluate the diagnostic accuracy of CTA in detecting intracranial aneurysms in the setting of SAH. METHODS: A single‐center, retrospective cohort of 643 patients was reviewed. A total of 401 patients were identified whose diagnostic workup included both CTA and confirmatory digital subtraction angiography (DSA). Aneurysms missed by CTA but diagnosed by DSA were further stratified by size and location. RESULTS: Three hundred and thirty aneurysms were detected by CTA while DSA detected a total of 431 aneurysms. False positive CTA results were seen for 24 aneurysms. DSA identified 125 aneurysms that were missed by CTA and 83.2% of those were <5 mm in diameter. The sensitivity of CTA was 57.6% for aneurysms smaller than 5 mm in size, and 45% for aneurysms originating from the internal carotid artery. The overall sensitivity of CTA in the setting of SAH was 70.7%. CONCLUSION: The accuracy of CTA in the diagnosis of ruptured intracranial aneurysm may be lower than previously reported. CTA has a low sensitivity for aneurysms less than 5 mm in size, in locations adjacent to bony structures, and for those arising from small caliber parent vessels. It is our recommendation that CTA should be used with caution when used alone in the diagnosis of ruptured intracranial aneurysms.

Intracranial blister aneurysms: clip reconstruction techniques.

Intracranial blister aneurysms are difficult to treat cerebrovascular lesions that typically affect the anterior circulation. These rare aneurysms can lead to acute rupture which usually cannot be treated via endovascular methods, but still require urgent surgical intervention. Surgical options are limited given their unique pathology and often require a combination of wrapping and clip reconstruction. In this video we present two patients with acute subarachnoid hemorrhage secondary to ruptured blister aneurysms. We demonstrate several surgical techniques for repairing the vascular defect with and without intraoperative rupture. The video can be found here: http://youtu.be/nz-JM45uKQU.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Otologic and Audiologic Screening for Patients With Vestibular Schwannomas

QUESTION 1 What is the expected diagnostic yield for vestibular schwannomas when using a magnetic resonance imaging (MRI) to evaluate patients with previously published definitions of asymmetric sensorineural hearing loss? TARGET POPULATION These recommendations apply to adults with an asymmetric sensorineural hearing loss on audiometric testing. RECOMMENDATION Level 3: On the basis of an audiogram, it is recommended that MRI screening on patients with ≥10 decibels (dB) of interaural difference at 2 or more contiguous frequencies or ≥15 dB at 1 frequency be pursued to minimize the incidence of undiagnosed vestibular schwannomas. However, selectively screening patients with ≥15 dB of interaural difference at 3000 Hz alone may minimize the incidence of MRIs performed that do not diagnose a vestibular schwannoma. QUESTION 2 What is the expected diagnostic yield for vestibular schwannomas when using an MRI to evaluate patients with asymmetric tinnitus, as defined as either purely unilateral tinnitus or bilateral tinnitus with subjective asymmetry? TARGET POPULATION These recommendations apply to adults with subjective complaints of asymmetric tinnitus. RECOMMENDATION Level 3: It is recommended that MRI be used to evaluate patients with asymmetric tinnitus. However, this practice is low yielding in terms of vestibular schwannoma diagnosis (<1%). QUESTION 3 What is the expected diagnostic yield for vestibular schwannomas when using an MRI to evaluate patients with a sudden sensorineural hearing loss? TARGET POPULATION These recommendations apply to adults with a verified sudden sensorineural hearing loss on an audiogram. RECOMMENDATION Level 3: It is recommended that MRI be used to evaluate patients with a sudden sensorineural hearing loss. However, this practice is low yielding in terms of vestibular schwannoma diagnosis (<3%). The full guideline can be found at: https://www.cns.org/guidelines/guidelines‐management‐patients‐vestibular‐schwannoma/chapter_2.

Progesterone-only contraception is associated with a shorter progression-free survival in premenopausal women with WHO Grade I meningioma

The hormonally active nature of intracranial meningioma has prompted research examining the risk of tumorigenesis in patients using hormonal contraception. Studies exploring estrogen-only and estrogen/progesterone combination contraceptives have failed to demonstrate a consistent increased risk of meningioma. By contrast, the few trials examining progesterone-only contraceptives have shown higher odds ratios for risk of meningioma. With progesterone-only contraception on the rise, the risk of tumor recurrence with these specific medications warrants closer study. We sought to determine whether progesterone-only contraception increases recurrence rate and decreases progression-free survival in pre-menopausal women with surgically resected WHO Grade I meningioma. Comparative analysis of 67 pre-menopausal women taking hormone-based contraceptives (progesterone-only medication, n = 21; estrogen-only or estrogen/progesterone combination medication, n = 46) who underwent surgical resection of WHO Grade I intracranial meningioma was performed. Differences in demographics, degree of resection, adjuvant therapy and time to recurrence were compared between the two groups. Compared to patients taking combination or estrogen-only contraception, those taking progesterone-only contraception demonstrated a greater recurrence rate (33.3 vs. 19.6%) with a reduced time to recurrence (18 vs. 32 months, p = 0.038) despite a significantly shorter follow-up (p = 0.014). There were no significant demographic or treatment related differences. The results from this study suggest that exogenous progesterone-only medications may represent a specific contraceptive subgroup that should be avoided in patients with meningioma.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Intraoperative Cranial Nerve Monitoring in Vestibular Schwannoma Surgery

FACIAL NERVE MONITORING Question 1 Does intraoperative facial nerve monitoring during vestibular schwannoma surgery lead to better long‐term facial nerve function? Target Population This recommendation applies to adult patients undergoing vestibular schwannoma surgery regardless of tumor characteristics. Recommendation Level 3: It is recommended that intraoperative facial nerve monitoring be routinely utilized during vestibular schwannoma surgery to improve long‐term facial nerve function. Question 2 Can intraoperative facial nerve monitoring be used to accurately predict favorable long‐term facial nerve function after vestibular schwannoma surgery? Target Population This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Recommendation Level 3: Intraoperative facial nerve can be used to accurately predict favorable long‐term facial nerve function after vestibular schwannoma surgery. Specifically, the presence of favorable testing reliably portends a good long‐term facial nerve outcome. However, the absence of favorable testing in the setting of an anatomically intact facial nerve does not reliably predict poor long‐term function and therefore cannot be used to direct decision‐making regarding the need for early reinnervation procedures. Question 3 Does an anatomically intact facial nerve with poor electromyogram (EMG) electrical responses during intraoperative testing reliably predict poor long‐term facial nerve function? Target Population This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Recommendation Level 3: Poor intraoperative EMG electrical response of the facial nerve should not be used as a reliable predictor of poor long‐term facial nerve function. COCHLEAR NERVE MONITORING Question 4 Should intraoperative eighth cranial nerve monitoring be used during vestibular schwannoma surgery? Target Population This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Recommendation Level 3: Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted. Question 5 Is direct monitoring of the eighth cranial nerve superior to the use of far‐field auditory brain stem responses? Target Population This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Recommendation Level 3: There is insufficient evidence to make a definitive recommendation. The full guideline can be found at: https://www.cns.org/guidelines/guidelines‐manage‐ment‐patients‐vestibular‐schwannoma/chapter_4.