[To the origins of surgery for acoustic neuromas]. / K istokam khirurgii nevrinom slukhovogo nerva.

Acoustic neuroma is one of the most common tumors of the posterior cranial fossa. Its removal is always a challenge for the neurosurgeon and the patient. The history of surgery for acoustic neuromas is inextricably linked with the history of neurosurgery in general. The modern surgical community must know history and be able to use it. Only then will the development of surgery lead to the preservation of the quality of life of patients. In the history of surgery for acoustic neuromas, the stages of its development are clearly visible from the description of the clinical picture through the study of the anatomy of the cerebellopontine angle to modern microsurgical removal.

[Early results of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm]. / Analiz blizhaishikh rezul'tatov intraoperatsionnogo neirofiziologicheskogo monitoringa pri khirurgicheskom lechenii gemifatsial'nogo spazma.

BACKGROUND: Neurophysiological monitoring in surgery for hemifacial spasm has been used since the 1990s, when Moller et al. demonstrated the effectiveness of intraoperative assessment of lateral spread response (LSR) regarding postoperative outcomes. Currently, there are conflicting data on effectiveness and feasibility of this technique. Widespread hemifacial spasm determines the relevance of neurophysiological monitoring in surgical treatment of these patients. OBJECTIVE: To evaluate the effectiveness of various methods of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm regarding early postoperative outcomes. MATERIAL AND METHODS: The study group included 43 patients (8 men and 35 women) aged 26-68 years. We assessed severity of hemifacial spasm using the SMC Grading Scale. All patients underwent vascular decompression of the facial nerve under neurophysiological control: monitoring of transcranial motor evoked potentials from facial muscles (m. orbicularis oculi, m. orbicularis oris, m. mentalis) and recording unilateral LSR. The control group included 23 patients (4 men and 19 women) aged 29-83 years. In this group, facial nerve decompression was performed without neurophysiological control. The effect of neurophysiological monitoring on postoperative outcomes (in-hospital period and 3 postoperative months) after vascular decompression of the facial nerve was assessed using the SMC Grading Scale. We considered severity and incidence of spasms. RESULTS: Thirty-one (72%) patients in the main group had no spasms of mimic muscles at discharge. In the control group, there were no spasms in 15 patients (65%). At the same time, there were fewer Grade I patients in the control group (12%) compared to the main group (26%). Moreover, 27 (66%) and 12 (52%) patients were free from episodes of hemifacial spasm in both groups, respectively. Patients with hemifacial spasm grade I-II comprised 29% in the main group and 34% in the control group. The number of relapses within three months increased in the control group (13%). CONCLUSION: Intraoperative monitoring of transcranial motor evoked potentials from the facial muscles and LSR during vascular decompression of the facial nerve increases the efficiency of surgery for hemifacial spasm in early postoperative period. Less number of relapses and lower intensity of hemifacial spasm necessitate neurophysiological monitoring in neurosurgical treatment of these patients.

[Endoscopic fenestration of arachnoid cyst of posterior cranial fossa through third ventriculostomy]. / Endoskopicheskaya fenestratsiya arakhnoidal'noi kisty zadnei cherepnoi yamki cherez triventrikulostomu.

Arachnoid cysts (AC) are spaces with cerebrospinal fluid covered with arachnoid membrane. Most cysts are supratentorial and only 10-12% of ACs are found in posterior cranial fossa. This disease is usually diagnosed in childhood. In adults, ACs make up 1.4% of all focal lesions. ACs of posterior cranial fossa are often localized behind the cerebellum or in cerebellopontine angle. Most patients with cysts do not have permanent symptoms and should be followed-up. Surgery is indicated for cysts complicated by focal and hydrocephalic-hypertension symptoms. Microsurgical or endoscopic procedures are used. Surgical approach is determined by the closest location of cyst to brain surface. The authors report non-standard surgical approach for giant AC of posterior cranial fossa complicated by obstructive hydrocephalus, intracranial hypertension and visual function impairment. Endoscopic third ventriculostomy was followed by AC fenestration through ventriculostomy. Symptoms disappeared within 6 months after surgery.

[Hypoglossal schwannoma: case report and literature review]. / Nevrinoma pod''iazychnogo nerva: sluchai iz praktiki i obzor literatury.

Hypoglossal schwannoma is a rare tumor this frequency approximately less than 5% all non-vestibular schwannomas. Also, it may be sign of neurofibromatosis type 2. Usually, the tong deviation in side of the tumor is the first symptom of the disease. When the tumor size is increased, bulbar disorders and cervico-occipital pain are develop. MRI is the main method of diagnostic. Until the 1970s, mortality after surgical removal reached 50% and was due to bulbar and respiratory dysfunctions. Nowadays, the cause of death remains the same. After introduction stereotactic radiotherapy into clinical practice total removal is not necessary. The purpose of surgery stay is removal of intracranial part of the tumor and decompression of the brainstem (subtotal removal). Radiotherapy or radiosurgery is performed on the intracanal fragment of the tumor. The case of successful surgical treatment of a patient with hypoglossal schwannoma is presented in this article. Subtotal removal was performed via median suboccipital approach. Radiosurgery is planned for residual part of the tumor, located in the hypoglossal nerve channel.

[Treatment of petroclival meningiomas: current state of the problem]. / Lechenie petroklival'nykh meningiom: sovremennoe sostoianie problemy.

Petroclival meningiomas (PCMs) are benign, slowly growing tumors. Surgery still remains the main treatment option for them. The desire for total resection of large extended PCMs often leads to the development or worsening of persistent neurological deficits. This paper presents a review of the world literature devoted to petroclival meningiomas. We discuss the issues of PCM classification, biology, diagnosis, and selection of the optimal algorithm for their treatment.

[Intraoperative fluorescence diagnostics in surgery of intracranial meningiomas: analysis of 101 cases]. / Intraoperatsionnaia fluorestsentnaia diagnostika v khirurgii intrakranial'nykh meningiom: analiz 101 nabliudeniia.

Fluorescence diagnostics has been extensively applied in surgery of malignant brain gliomas. However, the use of this technique in surgery of intracranial meningiomas has remained controversial. OBJECTIVE: The study objective was to assess the sensitivity of 5-aminolevulinic acid-based (5-ALA) fluorescence diagnostics in surgery of brain meningiomas and to clarify the clinical and biological factors that may influence the fluorescent effect. MATERIAL AND METHODS: The study consistently included 101 patients with intracranial meningiomas of various locations who were operated on using 5-ALA. There were 28 (27.72%) males and 73 (72.27%) females (median age, 54 years). In all patients, surgery was performed using an operating microscope equipped with a fluorescent module; in 24 of these, laser spectroscopy was used. For comparison of chances to observe the fluorescent effect of 5-ALA in patients having meningiomas with different WHO histological grades (Grade I vs Grade II-III), we performed a meta-analysis that included 10 studies (the largest series) on outcomes of surgical treatment of meningiomas using intraoperative fluorescence diagnostics. RESULTS: Of 101 patients included in this series, observable fluorescence was detected in 95 (94.1%) patients: weak fluorescence in 12 (11.9%), moderate fluorescence in 23 (22.8%) cases, and strong fluorescence in 60 (59.4%) patients. There was no statistically significant relationship (p>0.05) between the rate and intensity of observable fluorescence and the tumor growth pattern (primary/continued), location, WHO grade of malignancy, and histological subtype. In the absence of intraoperative bleeding, tumor fluorescence was statistically significantly brighter (p=0.02). Of 26 patients with hyperostosis, bone fluorescence was observed in 11 (42.3%) cases. There was no statistically significant relationship between administration of dexamethasone, its dose, administration of anticonvulsants, gastrointestinal tract diseases, as well as diabetes mellitus and the fluorescence intensity. There was also no significant relationship between the extent of tumor resection (Simpson scale) and the presence of fluorescence as well as its intensity. Comparison of the observable fluorescence intensity and the laser spectroscopy indicators revealed a significant correlation (r=0.75; p=0.005). CONCLUSION: Meningioma is a well fluorescent tumor, with the technique sensitivity being 94.1%. In some cases, the use of fluorescence diagnostics in surgery of meningiomas improves identification of residual tumor fragments and enables correction of a surgical approach. To assess the effect of fluorescence diagnostics on the recurrence rate and disease-free duration, further research is required.

[Surgical approach to resection of vestibular schwannomas following stereotactic radiological treatment. Surgical outcomes and morphological changes in tumors after radiotherapy]. / Khirurgicheskaia taktika pri udalenii vestibuliarnykh shvannom posle stereotaksicheskogo radiologicheskogo lecheniia. Rezul'taty operatsii i morfologicheskie izmeneniia v opukholiakh posle oblucheniia.

INTRODUCTION: Radiation therapy of small vestibular schwannomas is quite often used as an effective alternative to surgical treatment. At the same time, 2-10% of patients are detected with radioresistant tumors progressing to varying degrees, which is associated with continued tumor growth. In these cases, a decision on surgical resection or re-irradiation of the tumor is made depending on the neurological symptoms, patient's somatic status, and neuroimaging data. Surgical outcomes and intraoperative findings in pre-irradiated patients have been poorly represented in the literature, for which reason we decided to conduct this study. The paper presents a series of patients with vestibular schwannomas who underwent surgical removal of the tumor after radiotherapy. MATERIAL AND METHODS: A total of 39 patients with vestibular schwannomas after radiotherapy underwent surgery at the Burdenko Neurosurgical Institute in 2007-2017. Of these, 22 patients had a tumor removed after a previously performed combined surgical and radiotherapy treatment (group I), and 17 patients underwent tumor resection after previous radiological treatment (group II). The surgical outcomes were studied depending on various factors, and an analysis of the morphological changes in vestibular schwannomas after radiological treatment was carried out. RESULTS: In group I, the tumor was resected totally in 18% of patients, almost totally in 5% of patients, subtotally in 68% of patients, and partially in 9% of patients. In group II, the tumor was resected totally in 6% of patients, almost totally in 12% of patients, subtotally in 76% of patients, and partially in 6% of patients. We found that post-radiation changes in patients undergoing surgery led to an increase in the response of neurovascular structures to surgical intervention, development of pronounced fibrosis around tumors, and changes in the structure of tumors that became more solid. As a result, surgical morbidity increased, and the patient's quality of life after surgery deteriorated.

[A malignant peripheral nerve sheath tumor developed from the auditory nerve: a case report and a literature review]. / Zlokachestvennaia opukhol' obolochek perifericheskikh nervov, razvivshaiasia iz slukhovogo nerva: sluchai iz praktiki i obzor literatury.

We present a rare clinical case of a patient with a malignant peripheral nerve sheath tumor developed from the auditory nerve as well as a literature review, including 30 reported cases of this disease.

[Surgical management of venous compression causing trigeminal neuralgia]. / Khirurgicheskaia taktika pri venoznoĭ kompresii kak prichina trigeminal'noĭ nevralgii.

Venous compression is a rare cause of trigeminal neuralgia (TN). Vascular decompression of the trigeminal nerve root, as the only etiopathogenetic treatment of trigeminal neuralgia, is a well-known procedure that is extensively used at various neurosurgical clinics. As the number of interventions for TN increases, the absolute number of surgeries for eliminating venous compression of the trigeminal nerve also grows. Five hundred TN patients underwent surgery at the Neurosurgical Institute in the period from 2000 to 2015. The diagnosis was made based on the criteria of the International Classification of Headache Disorders, the 3rd edition, (ICHD-3) and the Burchiel classification. The study included 211 males and 289 females. The median age was 57 years. All patients had typical TN pain with a unilateral distribution. Two or more branches were affected in 90 patients; one branch was predominantly affected in 10 patients. The median disease duration was 16 months. The median visual analog scale (VAS) score was 8 (very severe persistent pain). In all cases, the patients underwent surgery using the retrosigmoid suboccipital approach. The median postoperative follow-up was 36 months. The aim of this work is to summarize the first experience of the Neurosurgical Institute in surgical treatment for venous compression of the Vth nerve root and suggest methods increasing the efficacy of vascular decompression in patients with this disease.

[Intracranial neurenteric cysts: experience of the Burdenko Neurosurgical Institute in the XXIth century]. / Intrakranial'naia neiroéntericheskaia kista: opyt Instituta neirokhirurgii im. akad. N.N. Burdenko, v XXI veke.

We present a series of cases of a rare pathology, intracranial neuroenteric cysts, a review of the international literature, and the experience in treating this pathology. MATERIAL AND METHODS: Seven patients with intracranial neuroenteric cysts underwent surgery at the Neurosurgical Institute in the period between 2000 and 2015. CONCLUSION: The main and only technique for treatment of intracranial neurenteric cysts is their resection.

[A technique of TachoComb application in dura mater reconstruction in surgery for posterior cranial fossa tumors]. / Metodika primeneniya materiala TakhoKomb dlya plastiki tverdoi mozgovoi obolochki v khirurgii opukholei zadnei cherepnoi yamki.

INTRODUCTION: Liquorrhea is a condition characterized by cerebrospinal fluid (CSF) leakage from the cranial cavity due to injury to the integrity of the dura mater (DM) and bone structures of the skull base. Surgery for posterior cranial fossa (PCF) lesions distinguishes wound CSF leakage when CSF leaks from a surgical wound as well as basal CSF leakage (nasal liquorrhea and, less often, otoliquorrhea). The main cause of basal CSF leakage is injury (including surgical injury) resulting in a defect in the DM and bone structures (cells of the mastoid process in the case of a suboccipital retrosigmoid approach). There are a variety of DM restoration techniques ranging from DM closure or placement of a synthetic or autologous patch to application of various synthetic adhesives in the form of adhesive compositions (Tissucol) and adhesive substances (TachoComb). This article describes the experience with application of a TachoComb® sponge gained at the 5th Clinical Department of the Burdenko Neurosurgical Institute. MATERIAL AND METHODS: The study included 176 patients with acoustic neurinomas. At the final stage of surgery, all the patients underwent DM reconstruction with a TachoComb® collagen sponge. CSF leakage occurred in 3 (1.7%) patients, with each of them having Koos grade 4 tumor. One (0.56%) patient had wound liquorrhea, and 2 (1.1%) patients had nasal liquorrhea. CSF leakage was managed by placement of a lumbar drain; postoperative wound revision was not required. CONCLUSION: Using the TachoComb® sponge for DM reconstruction in PCF surgery is an effective way to prevent postoperative CSF leakage, provided that the algorithm of manipulations described in the article is followed.

[Use of surgical approaches to the posterior cranial fossa in patients in a lying position]. / Primenenie khirurgicheskikh dostupov k zadnei cherepnoi yamke v polozhenii lezha.

BACKGROUND: Various suboccipital approaches are extensively used in modern neurosurgery for treatment of posterior cranial fossa disease. The main patient's positions on the operating table during surgery are half-sitting and lying ones. MATERIAL AND METHODS: The article provides a detailed description and methodology of retrosigmoid suboccipital and median suboccipital approaches in a lying position. CONCLUSION: The retrosigmoid suboccipital and median suboccipital approaches in a lying position, when used correctly, provide a good view of the operating field with the minimal risk of complications associated with the patient's position on the operating table.

[Endoscopic assistance in surgery of cerebellopontine angle tumors].

During the period of 2010-2012, 33 patients with cerebellopontine angle tumors were operated on at the Burdenko Neurosurgical Institute (Moscow, Russia) using different types of endoscopic assistance. All patients were operated on via the retrosigmoid suboccipital approach in semi-sitting and prone positions. 30° and 70° endoscopes were used during the surgery. Endoscopic assistance allowed us to increase the completeness of tumor removal and to reduce the risk of postoperative complications by retaining the anatomic integrity of cranial nerves and vascular structures in the base of the posterior cranial fossa. These benefits made it possible to maintain and improve quality of life in patients with CPA tumors in the postoperative period.

[Patient positioning on the operating table in neurosurgery: sitting or lying].

Efficacy and safety of microvascular decompression of trigeminal nerve depending on the position on the operating table were assessed in 200 neurosurgical patients in retrospective observational study It was shown that efficacy doesn't depend on positioning. Lying position eliminates probability of such complications as postural hypotension, hypotension during surgery, tension pneumocephalus and peripheral nerves injury. Sitting position increases risk of air venous embolism by 25 times. Lying position increases risk of postoperative nasal liquorrhea by 4 times, but eliminates risk of postoperative paresis of trigeminal nerve. It is also decreases risk of corneal reflex reduction by 3 times, hyperpathia by 2 times and paresthesias by 5 times, but increases probability of postoperative hyperesthesia by 4 times. Microvascular decompression of trigeminal nerve in lying position is safer than similar operation in sitting position.

[Endoscopic assistance in microvascular decompression of cranial nerves].

Microvascular decompression (MVD) is an effective method for treatment of trigeminal neuralgia (TN), hemifacial spasm (HFS), glossopharyngeal neuralgia (GPN). The aim of this study was to assess the role of endoscopic assistance in MVD for the treatment of cranial neuropathies. Since 2009 till 2011 133 patients with cranial neuropathies were treated by MVD in Burdenko Neurosurgical Institute, Moscow. In 22 patients (11 patients with HFS, 10 patients with TN, 1 with GPN) endoscopic assistance was applied during the MVD. We used minimally invasive retrosigmoid approach in a unilateral position. Cerebellopontine angle was explored by 30-degree or 70-degree telescope to visualize the root entry zone of trigeminal, facial or glossopharyngeal nerves and to locate the neurovascular conflict. In 9 patients with HFS and in 1 patient with TN and in another patient with GPN endoscopy discovered offending vessels that were not visible through the microscope. In all cases endoscope was used to exclude another site of compression and to verify decompression and to identify position of teflon and offending vessel after MVD. Immediately after the surgery excellent outcome was observed in 10 patients with HFS (89%), one patient was reoperated 1.5 years after first operation with positive effect. Relief of pain in early postoperative period was observed in patients with TN and GPN. There were no major complications and postoperative mortality in our series. Endoscopic assistance is very effective and helpful technique in MVD of cranial nerves, especially in cases with HFS. In this study the use of the endoscope allowed to identify the site of compression and to confirm the position of teflon after MVD.

[Endoscopically assisted removal of posterior fossa meningioma combined with microvascular decompression of trigeminal nerve root (early experience)].

The article presents an example of endoscopically assisted neurosurgical removal of petrous apex meningioma associated with trigeminal neuralgia. Endoscopy was used during the operation for control of completeness of tumor removal and for identification of offending vessel and control of position of protector. Total resection of the tumor was achieved, complete regression of trigeminal pain was observed in early postoperative period.