[Facial Nerve Schwannomas].

Facial nerve schwannomas (FNSs) are rare, benign tumors that can arise along segments of the facial nerve, including the cerebellopontine angle, internal auditory canal, middle fossa, and temporal bones. Although traditionally managed with gross total resection and facial nerve reconstruction, the resulting facial nerve palsy has prompted a paradigm shift toward functional preservation. Based on>70 surgical cases, we established a tailored strategy based on preoperative facial nerve function and intraoperative facial nerve electromyograms.

Long-term prognosis of preserved hearing function after surgery in patients with cerebellopontine angle tumors other than vestibular schwannoma.

Background: In our previous study on vestibular schwannomas (VSs), we found that preserved useful hearing function in patients immediately after surgery gradually deteriorated in long-term period, and was lost in 13% of patients 5 years after surgery. In this retrospective study, we aimed to investigate the long-term hearing prognosis of patients with cerebellopontine angle (CPA) tumors other than VSs, and clarify whether the phenomenon of hearing deterioration after surgery occurs only in patients with VSs.

Method: Patient backgrounds and otologic data were investigated in 70 patients (meningioma: 37; trigeminal schwannoma: 9; facial nerve schwannoma: 4; jugular foramen schwannoma: 9; and epidermoid cysts: 11) with preserved useful hearing function after surgery (American Academy of Otolaryngology-Head and Neck Surgery classification Class A or B).

[Posterior Fossa Anatomy for Microvascular Decompression Surgery].

In most microvascular decompression surgeries, surgical maneuvers are performed within normal anatomical structures without any neoplasms. Thus, detailed anatomical knowledge is essential to perform safe and efficient procedures. "Rule of 3" by Rhoton AL Jr.

Telovelar/Transcerebellomedullary Fissure Approach: Giant Distal Posterior Inferior Cerebellar Artery Aneurysm, Epidermoid Cyst, and Brainstem Cavernoma: 2-Dimensional Operative Video.

Indications Corridor And Limits Of Exposure: The telovelar or transcerebellomedullary fissure approach can provide wide exposure of the cerebellomedullary fissure and fourth ventricle by separating the natural plane between the medulla and cerebellum. 1-5.

Anatomic Essentials Need For Preoperative Planning And Assessment: The cerebellar tonsil is attached to the adjacent cerebellum only by the tonsillar peduncle at its superolateral edge.

Resection of petroclival clear cell meningioma by the anterior transpetrosal approach: diagnosis of rare pathology and improvement of preoperative hearing disturbance.

Clear cell meningioma is a rare histological variant of meningioma, which often recurs aggressively. This video demonstrates a patient with a petroclival clear cell meningioma, which was resected completely through the anterior transpetrosal approach. The absence of intratumoral spotty signal voids on preoperative susceptibility-weighted imaging (SWI) suggested that the tumor was a meningioma rather than a schwannoma, although typical imaging features of meningioma were not observed.

Pediatric vestibular schwannoma without evidence of neurofibromatosis: consecutive 18 microsurgical experiences.

Purpose: Sporadic vestibular schwannoma (VS) is rare in children in contrast to adults, and detailed investigations of case series of these patients using a single fixed protocol are scarce. This study presents our surgical experience of pediatric VSs without clinical evidence of neurofibromatosis type 2 (NF2) at the initial diagnosis.

Methods: Among 1385 consecutive sporadic VS surgeries, 18 pediatric patients (1.

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.

Preoperative Facial Nerve Palsy in Patients With Vestibular Schwannoma: Clinical Features and Postoperative Functional Prognosis in a Case Series of 34 Among 1228 Consecutive Patients.

Background: Facial nerve palsy is a rare presenting symptom of vestibular schwannomas and has not been investigated in detail.

Objective: To investigate the incidence, clinical features, and postoperative long-term outcomes of facial nerve function in patients with vestibular schwannomas causing preoperative facial nerve palsy.

Methods: After excluding patients with neurofibromatosis type 2 and those with prior treatment, 1228 consecutive patients who underwent vestibular schwannoma surgery were retrospectively investigated.

Evolution of microneurosurgical anatomy with special reference to the history of anatomy, surgical anatomy, and microsurgery: historical overview.

This article reviews the evolution of microneurosurgical anatomy (MNA) with special reference to the development of anatomy, surgical anatomy, and microsurgery. Anatomy can be said to have started in the ancient Greek era with the work of Hippocrates, Galen, and others as part of the pursuit of natural science. In the sixteenth century, Vesalius made a great contribution in reviving Galenian knowledge while adding new knowledge of human anatomy.

Importance of appropriate surgical approach selection for radical resection of cerebellopontine angle epidermoid cysts with preservation of cranial nerve functions: our experience of 54 cases.

Background: Although many reports state that only the lateral suboccipital retrosigmoid approach (LSO) should be used for removal of cerebellopontine angle (CPA) epidermoid cysts, it is preferable to use various surgical approaches as appropriate for each patient, for radical resection with an optimal operative field under direct visualization, and for the preservation of cranial nerve (CN) functions. In the present study, we hence focused on the importance of surgical approach selection for removal of CPA epidermoid cysts and analyzed the results of CPA epidermoid cysts after surgery in our series.

Methods: Fifty-four patients who underwent surgery for CPA epidermoid cysts were retrospectively analyzed, regarding their surgical approaches, removal rates, preservation rates of CN function 1 year after surgery, and recurrence.

Intraoperative continuous vagus nerve monitoring with repetitive direct stimulation in surgery for jugular foramen tumors.

Objective: Surgery for tumors around the jugular foramen has significant risks of dysphagia and vocal cord palsy due to possible damage to the lower cranial nerve functions. For its treatment, long-term tumor control by maximum resection while avoiding permanent neurological damage is required. To accomplish this challenging goal, the authors developed an intraoperative continuous vagus nerve monitoring system and herein report their experience with this novel neuromonitoring method.

Microvascular decompression for trigeminal neuralgia caused by trigeminocerebellar artery.

In this operative video, the authors demonstrate the case of a 53-year-old woman who presented with typical right trigeminal neuralgia by a trigeminocerebellar artery (TCA). The TCA was first defined by Marinković as a unique branch of the basilar artery supplying both the trigeminal nerve root and the cerebellar hemisphere. As a result of the close relationship between this vessel and the nerve root, the TCA might compress the nerve root, thereby causing trigeminal neuralgia.

Long-term prognosis of preserved useful hearing after surgery in patients with vestibular schwannoma: a study of 91 cases.

Background: In patients with a vestibular schwannoma, some studies have reported that useful hearing preserved initially after surgery deteriorates gradually in the long term. Studies with more patients are needed to clarify the maintenance rate of postoperative hearing function and to identify prognostic of hearing function.

Method: Ninety-one patients (mean age, 39.

Management of Sigmoid Sinus Injury: Retrospective Study of 450 Consecutive Surgeries in the Cerebellopontine Angle and Intrapetrous Region.

Background: The sigmoid sinus is the biggest obstacle when approaching the posterior fossa and temporal bone. Adequate sinus exposure is required to obtain a sufficient operative field, but sinus injury is a potentially life-threatening complication.

Objective: To present our experience of sigmoid sinus injury and its management during surgeries in the cerebellopontine angle and intrapetrous region, with operative videos.

Evolution of cerebellomedullary fissure opening: its effects on posterior fossa surgeries from the fourth ventricle to the brainstem.

Surgical approaches to the fourth ventricle and its surrounding brainstem regions have changed significantly in the previous 30 years, after the establishment of cerebellomedullary fissure (CMF) opening. With the development of CMF opening techniques, CMF opening surgeries have become widely used for the treatment of various pathologies and have contributed to the improvement of surgical results in posterior fossa surgeries. We here review the historical progress of CMF opening surgeries to help the future progression of neurosurgical treatments.

Arterial spin labeling imaging correlates with the angiographic and clinical vascularity of vestibular schwannomas.

Purpose: Hypervascular vestibular schwannomas (HVSs) are a type of the vestibular schwannomas (VSs) that are extremely difficult to remove. We examined whether HVSs can be predicted by using arterial spin labeling (ASL) imaging.

Methods: A total of 103 patients with VSs underwent ASL imaging and digital subtraction angiography (DSA) before surgery.

Extradural Transjugular Transsigmoid Approach with High Cervical Exposure for Glomus Jugulare Tumor.

Surgical removal of glomus jugulare tumors is challenging owing to the complex anatomy of the temporal bone and craniocervical region, aggressive tumor invasion into the nearby structures, and their hypervascularity. However, recent advances in skull base techniques, intraoperative neuromonitoring, and radiological interventions have enabled their relatively safe resection, while giving priority to functional preservation. This video demonstrates a case of a glomus jugulare tumor treated by the extradural transjugular transsigmoid approach with high-cervical exposure and tympamoplasty, after preoperative embolization.

Microsurgical resection of medullary cavernoma via the olivary zone by the retrosigmoid supracondylar approach.

Microsurgical resection of the medullary cavernoma is rare, comprising less than 15% of more than 250 surgeries of brainstem cavernoma performed by the senior author (H.B.).