Microsurgical resection of a right dumbbell-shaped jugular foramen schwannoma through a modified retrosigmoid infra-jugular approach: how I do it.

BACKGROUND: Surgical treatment of dumbbell jugular foramen schwannomas can be challenging. The main goals of surgery are maximal resection with preservation of function and overall patient quality of life. METHODS: In this paper, we present a step-by-step technical description of a microsurgical resection of dumbbell-shaped JF schwannoma using a modified retrosigmoid infra-jugular approach. CONCLUSION: The modified retrosigmoid infra-jugular is a safe and suitable approach in selected cases. This technique, however, must be limited only to those tumors with minimal extension into the jugular foramen.

Management of non-vestibular schwannomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section Part III: Lower cranial nerve schwannomas, jugular foramen (CN IX, X, XI) and hypoglossal schwannoma (XII).

BACKGROUND: Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear, and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations. METHODS: A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the third of a three-part series describing non-vestibular schwannomas (IX, X, XI, XII). RESULTS: A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to preoperative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies and follow-up management. CONCLUSION: This article represents the consensually derived opinion of the task force with respect to the treatment of non-vestibular schwannomas. For each of these tumours, the management paradigm is shifting towards the compromise between function preservation and progression free survival.

Post-surgical Hearing Improvement in a Case of Jugular Foramen Schwannoma Despite the Lack of Response in a Preoperative Auditory Brainstem Response Test.

We report a rare case involving improved hearing after surgery for a jugular foramen schwannoma despite the lack of response during the preoperative auditory brainstem response (ABR) test. A left jugular foramen tumor was diagnosed in a 79-year-old man with hearing loss. No response was observed during the preoperative ABR test. However, his hearing improved after surgery using the lateral suboccipital approach. Following Gamma Knife radiation to the residual tumor post-surgery, the ABR test detected V waves. The hearing of patients with cerebellopontine angle tumors can improve even when there is no response during the preoperative ABR test.

Features of postoperative hearing function changes in patients with cerebellopontine angle and intratemporal tumors other than vestibular schwannomas.

OBJECTIVE: Tumors around the cerebellopontine angle (CPA) and temporal bone can potentially affect hearing function. In patients with such tumors other than vestibular schwannomas (VSs), auditory tests were investigated before and after surgery to characterize the auditory effect of each tumor and to determine prognostic factors. METHODS: A total of 378 patients were retrospectively evaluated for hearing functions before and after surgery. These 378 patients included 168 with CPA meningioma, 40 with trigeminal schwannoma (TS), 55 with facial nerve schwannoma (FNS), 64 with jugular foramen schwannoma (JFS), and 51 with CPA epidermoid cyst (EPD). RESULTS: Preoperative hearing loss was observed in 124 (33%) of the 378 patients. Of these 124 patients, 38 (31%) experienced postoperative hearing improvement. Postoperative hearing deterioration occurred in 67 (18%) of the 378 patients. The prognostic factors for postoperative hearing improvement were younger age and the retrocochlear type of preoperative hearing disturbance. Tumor extension into the internal auditory canal was correlated with preoperative hearing loss and postoperative hearing deterioration. Preoperative hearing loss was observed in patients with FNS (51%), JFS (42%), and MGM (37%), and postoperative hearing improvement was observed in patients with JFS (41%), MGM (31%), and FNS (21%). Postoperative hearing deterioration was observed in patients with FNS (27%), MGM (23%), and EPD (16%). CONCLUSIONS: According to the results of this study in patients with CPA and intratemporal tumors other than VS, preoperative retrocochlear hearing disturbance was found to be a prognostic factor for hearing improvement after surgery. Among the tumor types, JFS and MGM had a particularly favorable hearing prognosis. The translabyrinthine approach and cochlear nerve section should be avoided for these tumors, regardless of the patient's preoperative hearing level.

Early-onset adverse events after stereotactic radiosurgery for jugular foramen schwannoma: a mid-term follow-up single-center review of 46 cases.

BACKGROUND: Recently, stereotacitc radiosurgery (SRS) has been in the spotlight as an alternative therapeutic option for jugular foramen schwannomas (JFS). While most reported studies focus on the long-term efficacy and safety issues of SRS, none describe the early-onset adverse events (eAEs). We aimed to investigate the incidence, clinical characteristics, and mid-term outcomes of eAEs occurring within six months after SRS for JFS. METHODS: In this retrospective review, patients who underwent at least six months of follow-up were included among all patients with JFS who have performed SRS at our institution between July 2008 and November 2019. And eAEs were defined as a newly developed neurological deficit or aggravation of pre-existing symptoms during the first six months after SRS. RESULTS: Forty-six patients were included in the analysis. The median follow-up period was 50 months (range 9-136). The overall tumor control rate was 91.3%, and the actuarial 3-, 5-, and 10-year progression-free survival rates were 97.8%, 93.8%, and 76.9%, respectively. Of the 46 patients, 16 had eAEs, and the median time to onset of eAEs was one month (range 1-6 months), and the predominant symptoms were lower cranial nerve dysfunctions. Thirteen of 16 patients showed improved eAE symptoms during the follow-up period, and the median resolution time was six months (range 1-52). In 11 (68.8%) of 16 patients with eAEs, transient expansions were observed with a mean of 3.6 months after the onset of eAEs, and the mean difference between the initial tumor volume and the transient expansion volume was more prominent in the patients with eAEs (3.2 cm3 vs. 1.0 cm3; p = 0.057). In univariate analysis, dumbbell-shaped tumors (OR 10.56; p = 0.004) and initial tumor volume (OR 1.32; p = 0.033) were significantly associated with the occurrence of eAEs. CONCLUSIONS: Although acute adverse events after SRS for JFS are not rare, these acute effects were not permanent and mostly improved with the steroid treatment. Dumbell-shaped and large-volume tumors are significant predictive factors for the occurrence of eAEs. And the transient expansion also seems to be closely related to eAEs. Therefore, clinicians need to be more cautious when treating these patients and closely monitor the occurrence of eAEs.

Intratumoral hemorrhage in jugular foramen schwannoma after stereotactic radiosurgery: A case report.

BACKGROUND: Clinically significant intratumoral hemorrhage is a rare complication of stereotactic radiosurgery (SRS) for benign tumors. CASE DESCRIPTION: Here, we present the case of a 64-year-old man who underwent SRS for a relatively large dumbbell-shaped left jugular foramen schwannoma (JFS) and thereafter developed intratumoral hemorrhage. On post-SRS day 3, he developed lower cranial nerve palsies with radiographically evident tumor expansion. His neurological conditions had gradually improved thereafter; however, he suddenly developed headache, dizziness, and mild hearing deterioration at 7 months due to intratumoral hemorrhage. We managed the patient conservatively, and eventually, his symptoms improved except for slight ataxia and hearing deterioration. Follow-up images at 4 years from SRS demonstrated significant tumor shrinkage. This is the first report describing intratumoral hemorrhage after SRS for JFS. CONCLUSION: Transient expansion of the tumor and subsequent venous stasis around the tumor may have played a role in the hemorrhage. Intratumoral hemorrhage should be considered as a rare, but potential complication of SRS for JFSs.

Hearing improvement after resection of a large jugular foramen schwannoma: case report.

Although hearing improvement after surgery for small tumors of the cerebellopontine angle has been reported, the mechanism by which surgery leads to the improvement in hearing remains controversial. We report a patient who sought treatment for progressive tinnitus and hearing loss. Magnetic resonance imaging showed a large (5-cm) schwannoma in the cerebellopontine angle. At surgery the lesion was found to originate from rootlets of cranial nerve X at the jugular foramen. The patient underwent gross total resection of the tumor. Immediately after surgery, his hearing improved dramatically. We believe that our patient represents an example of hearing impairment at least in part referable to direct compression of the brainstem. Importantly, the patient's hearing deficit was completely reversible. Some authors claim that surgery to preserve hearing may be contraindicated in patients with speech discrimination scores below 50%. However, when extrinsic brainstem compression may contribute to the cause of such a hearing decrement, postoperative improvement in hearing may be a reasonable expectation.

Stereotactic radiosurgery for jugular foramen schwannomas: an international multicenter study.

OBJECTIVE: For some jugular foramen schwannomas (JFSs), complete resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery (SRS) is a minimally invasive alternative or adjunct to microsurgery for JFSs. The authors reviewed clinical and imaging outcomes of SRS for patients with these tumors. METHODS: Nine participating centers of the International Gamma Knife Research Foundation identified 92 patients who underwent SRS between 1990 and 2013. Forty-one patients had prior subtotal microsurgical resection. The median interval between previous surgery and SRS was 15 months (range 0.5-144 months). Eighty-four patients had preexisting cranial nerve (CN) symptoms and signs. The median tumor volume was 4.1 cm3 (range 0.8-22.6 cm3), and the median margin dose was 12.5 Gy (range 10-18 Gy). Patients with neurofibromatosis were excluded from this study. RESULTS: The median follow-up was 51 months (range 6-266 months). Tumors regressed in 47 patients, remained stable in 33, and progressed in 12. The progression-free survival (PFS) was 93% at 3 years, 87% at 5 years, and 82% at 10 years. In the entire series, only a dumbbell shape (extension extracranially via the jugular foramen) was significantly associated with worse PFS. In the group of patients without prior microsurgery (n = 51), factors associated with better PFS included tumor volume < 6 cm3 (p = 0.037) and non-dumbbell-shaped tumors (p = 0.015). Preexisting cranial neuropathies improved in 27 patients, remained stable in 51, and worsened in 14. The CN function improved after SRS in 12% of patients at 1 year, 24% at 2 years, 27% at 3 years, and 32% at 5 years. Symptomatic adverse radiation effects occurred in 7 patients at a median of 7 months after SRS (range 5-38 months). Six patients underwent repeat SRS at a median of 64 months (range 44-134 months). Four patients underwent resection at a median of 14 months after SRS (range 8-30 months). CONCLUSIONS: Stereotactic radiosurgery proved to be a safe and effective primary or adjuvant management approach for JFSs. Long-term tumor control rates and stability or improvement in CN function were confirmed.

Gamma Knife surgery for patients with jugular foramen schwannomas: a multiinstitutional retrospective study in Japan.

OBJECTIVE This study aimed to explore the efficacy and safety of stereotactic radiosurgery in patients with jugular foramen schwannomas (JFSs). METHODS This study was a multiinstitutional retrospective analysis of 117 patients with JFSs who were treated with Gamma Knife surgery (GKS) at 18 medical centers of the Japan Leksell Gamma Knife Society. The median age of the patients was 53 years. Fifty-six patients underwent GKS as their initial treatment, while 61 patients had previously undergone resection. At the time of GKS, 46 patients (39%) had hoarseness, 45 (38%) had hearing disturbances, and 43 (36%) had swallowing disturbances. Eighty-five tumors (73%) were solid, and 32 (27%) had cystic components. The median tumor volume was 4.9 cm3, and the median prescription dose administered to the tumor margin was 12 Gy. Five patients were treated with fractionated GKS and maximum and marginal doses of 42 and 21 Gy, respectively, using a 3-fraction schedule. RESULTS The median follow-up period was 52 months. The last follow-up images showed partial remission in 62 patients (53%), stable tumors in 42 patients (36%), and tumor progression in 13 patients (11%). The actuarial 3- and 5-year progression-free survival (PFS) rates were 91% and 89%, respectively. The multivariate analysis showed that pre-GKS brainstem edema and dumbbell-shaped tumors significantly affected PFS. During the follow-up period, 20 patients (17%) developed some degree of symptomatic deterioration. This condition was transient in 12 (10%) of these patients and persistent in 8 patients (7%). The cause of the persistent deterioration was tumor progression in 4 patients (3%) and adverse radiation effects in 4 patients (3%), including 2 patients with hearing deterioration, 1 patient with swallowing disturbance, and 1 patient with hearing deterioration and hypoglossal nerve palsy. However, the preexisting hoarseness and swallowing disturbances improved in 66% and 63% of the patients, respectively. CONCLUSIONS GKS resulted in good tumor control in patients with either primary or residual JFSs. Although some patients experienced some degree of symptomatic deterioration after treatment, persistent adverse radiation effects were seen in only 3% of the entire series at the last follow-up. Lower cranial nerve deficits were extremely rare adverse radiation effects, and preexisting hoarseness and swallowing disturbances improved in two-thirds of patients. These results indicated that GKS was a safe and reasonable alternative to surgical resection in selected patients with JFSs.

Nonparaganglioma jugular foramen tumors.

This article discusses the epidemiology, presentation, and diagnostic work-up of nonparaganglioma jugular foramen tumors, and the management options and predicted outcomes. Paragangliomas are the most common jugular foramen tumors, but other nonparagangliomas are important to consider in a differential for jugular foramen tumors. This article specifically focuses on jugular foramen schwannomas, meningiomas, metastatic disease, and regional pathologies that may extend to the jugular foramen, such as endolymphatic sac tumors, chordomas, and chondrosarcomas. Operative approaches to these tumors are also reviewed.

Stereotactic radiosurgery for nonvestibular schwannomas.

This article summarizes tumor control and functional outcomes of stereotactic radiosurgery (SRS) for patients with nonvestibular schwannomas, in comparison with those treated with microsurgical resection. To date, surgical resection has been a common treatment for nonvestibular schwannomas. Because these tumors are generally benign, complete tumor resection is a desirable curative treatment. However, it is almost infeasible to completely remove these tumors without any complications, even for experienced neurosurgeons, because of adherence to surrounding critical structures such as cranial nerves, brainstem, or vessels. SRS provides a good tumor control rate with much less morbidity than microsurgical resection.

Long-term outcomes after surgical treatment of jugular foramen schwannoma.

The purpose of this article is to clarify long-term outcomes following surgery for jugular foramen schwannomas. Fifteen adult patients underwent surgery, predominantly via the lateral suboccipital approach, for jugular foramen schwannomas between December 1987 and May 2007. All information was collected retrospectively from patient medical records at a university hospital. The main outcome measures were tumor regrowth and IX-X nerve function at median 84.3 months (range, 12 to 166 months) following surgery. Near total removal was achieved in 10 patients, and the remaining 5 patients had subtotal removal. Tumor regrowth was observed in 9 of 15 patients at 6 to 89 months (mean, 31.2 months) after surgery. The actual tumor control rate was 70.0 +/- 12.8% at 5 years. Fourteen of 15 patients exhibited IX-X nerve dysfunction immediately after surgery, but 8 of these 14 patients experienced amelioration of the symptoms at the final follow-up period. No patients required additional treatment. We found in our study that for jugular foramen schwannoma, tumor volume should be reduced as much as possible to avoid severe IX-X nerve damages postoperatively. If a small amount of tumor remains, long-term follow-up is necessary.