One-step orbit reconstruction using PMMA implants following hyperostotic sphenoid wing meningioma removal: Evolution of the technique in short clinical series

Purpose

To report our experience with patient specific implants for one-step orbit reconstruction following hyperostotic SWM removal and to describe the evolution of the technique through three surgical cases. Methods: Three cases of one-step SWM removal and orbit reconstruction are described. All cases are given consecutively to describe the evolution of the technique. Hyperostotic bone resection was facilitated by electromagnetic navigation and cutting guides (templates). Based on a 3D model, silicone molds were made using CAD/CAM. Then PMMA implant was fabricated from these molds. The implant was adjusted and fixed to the cranium with titanium screws after tumor removal. Results: Following steps of the procedure changed over these series: hyperostotic bone resection, implant thickness control, implant overlay features, anatomic adjustments, implant fixation. The proptosis resolved in all cases. In one patient the progressive visual acuity deterioration was recognized during the follow-up. No oculomotor disturbances and no tumor regrowth were found at the follow-up.

Conclusion

CAD/CAM technologies enable creation of implants of any size and configuration, and thereby, to increase the extent of bony resection and lower the risk of tumor progression. The procedure is performed in one step which decreases the risk of postoperative morbidity.

[Primary tumors of the brain stem. State of the problem]

Primary brainstem gliomas are still poorly studied in neurooncology. This concept includes tumors with different histological and genetic features, as well as variable clinical course and outcomes. Nevertheless, treatment implies radiotherapy without a clear idea of morphological substrate of disease in 80% of cases. Small number of studies and insufficient data on histological and genetic nature of brainstem tumors complicate clear diagnostic and treatment algorithms. This review provides current information regarding primary glial brainstem tumors. Appropriate problems and objectives are highlighted. The purpose of the review is to provide a comprehensive and updated understanding of the current state of brainstem glial tumors and to identify areas requiring further study for improvement of diagnosis and treatment of these diseases. Brainstem tumors are an understudied problem with small amount of data that complicates optimal treatment strategies. Further researches and histological verification are required to develop new methods of therapy, especially for diffuse forms of neoplasms.

Stability and Thrombogenicity Analysis of Collagen/Carbon Nanotube Nanocomposite Coatings Using a Reversible Microfluidic Device

Currently, the development of stable and antithrombogenic coatings for cardiovascular implants is socially important. This is especially important for coatings exposed to high shear stress from flowing blood, such as those on ventricular assist devices. A method of layer-by-layer formation of nanocomposite coatings based on multi-walled carbon nanotubes (MWCNT) in a collagen matrix is proposed. A reversible microfluidic device with a wide range of flow shear stresses has been developed for hemodynamic experiments. The dependence of the resistance on the presence of a cross-linking agent for collagen chains in the composition of the coating was demonstrated. Optical profilometry determined that collagen/c-MWCNT and collagen/c-MWCNT/glutaraldehyde coatings obtained sufficiently high resistance to high shear stress flow. However, the collagen/c-MWCNT/glutaraldehyde coating was almost twice as resistant to a phosphate-buffered solution flow. A reversible microfluidic device made it possible to assess the level of thrombogenicity of the coatings by the level of blood albumin protein adhesion to the coatings. Raman spectroscopy demonstrated that the adhesion of albumin to collagen/c-MWCNT and collagen/c-MWCNT/glutaraldehyde coatings is 1.7 and 1.4 times lower than the adhesion of protein to a titanium surface, widely used for ventricular assist devices. Scanning electron microscopy and energy dispersive spectroscopy determined that blood protein was least detected on the collagen/c-MWCNT coating, which contained no cross-linking agent, including in comparison with the titanium surface. Thus, a reversible microfluidic device is suitable for preliminary testing of the resistance and thrombogenicity of various coatings and membranes, and nanocomposite coatings based on collagen and c-MWCNT are suitable candidates for the development of cardiovascular devices.

[Chordoid gliomas of the third ventricle]

BACKGROUND

Chordoid glioma is a rare slow-growing tumor of the central nervous system. Available world experience includes no more than 200 cases (lesion of the third ventricle in absolute majority of cases). Recognition and treatment of chordoid glioma are currently difficult problems due to small incidence of this disease.

OBJECTIVE

To describe clinical manifestations and surgical treatment of chordoid glioma of the third ventricle considering literature data and own experience.

MATERIAL AND METHODS

There were 12 patients (6 men and 6 women) with chordoid glioma between 2004 and 2023 (10 patients with lesion of the third ventricle, 1 - lateral ventricle, 1 - pineal region). Only patients with tumors of the third ventricle were analyzed.

RESULTS

Total and subtotal resection was performed in 1 and 3 cases, respectively. Five patients underwent partial resection, 1 patient underwent biopsy. The follow-up data were available in 7 out of 10 patients (mean 25 months). Radiotherapy was performed in 4 patients (continued tumor growth in 2 cases). One patient died.

CONCLUSION

Chordoid glioma is a benign tumor predominantly localized in the third ventricle. Preoperative MRI and CT in some cases make it possible to suspect chordoid glioma and differentiate this tumor from craniopharyngioma, meningioma and pituitary adenoma by such signs as isointense signal in T1WI, hyper- or isointense signal in T2WI, homogeneous contrast enhancement and edema of basal ganglia in T2 FLAIR images. The only effective treatment for chordoid glioma is surgery. Total resection is often impossible or extremely dangerous due to location of tumor, large size and invasion of the third ventricle. Postoperative mental disorders and diabetes insipidus, including severe hypernatremia, are common that requires mandatory monitoring of water and electrolyte balance.

[Magnetic resonance imaging of saccular intracranial aneurysm wall]

BACKGROUND

Hemorrhage from intracranial aneurysms is associated with high risk of adverse outcomes. In this regard, surgical treatment of unruptured asymptomatic aneurysms has been actively developed in recent decades. One of the objectives is searching for predictors of aneurysm rupture to clarify the indications for surgery. Non-invasive analysis of vascular wall is actively discussed in last years.

OBJECTIVE

To evaluate the possibilities of MRI of ruptured and unruptured intracranial aneurysm walls and determine clinical significance of certain morphological patterns.

MATERIAL AND METHODS

The study included 111 patients with 158 ruptured and unruptured saccular aneurysms who underwent MRI according to a special protocol between November 2020 and September 2023. We analyzed each aneurysm regarding features of contrast enhancement and changes in SWAN images. After that, we compared these data with ruptures.

RESULTS

Wall of ruptured and unruptured aneurysms can accumulate contrast agent. We found 5 types of contrast enhancement. Thick-layer contrast enhancement was accompanied by 9.6-fold higher risk of aneurysm rupture compared to aneurysms without contrast enhancement. Dark MR signal from intracranial aneurysm wall in SWAN imaging is a significant sign of rupture.

CONCLUSION

MRI of the vascular wall is valuable to verify ruptured aneurysms. Unruptured aneurysms can accumulate contrast agent inside the wall, and pattern of accumulation differs from ruptured aneurysms. Morphological analysis is needed to confirm contrast enhancement as a marker of aneurysm rupture.

Analysis of a Novel Entry Point for Freehand Ventriculostomy Using Computerized Tomography Scans

Background

External ventricular drain (EVD) placement is one of the most common procedures in neurosurgery. Neurosurgeons generally prefer to access the ventricles via Kocher’s point since it is the most common point of entry to this area; however, this point is used to describe different anatomic landmarks and is not well-defined.

Objective

The present study aims to describe and provide an anatomical assessment of a novel ventriculostomy access point developed by the authors using computerized tomography (CT) scans performed on 100 patients.

Materials and methods

Data were collected from 100 randomly selected patients with normal ventricular anatomy found on their 1.0 mm-slice CT scans performed at the Burdenko Neurosurgical Center from March 2019 to June 2021. The CT inclusion criteria were: CT slices < or = to 1 mm and absence of brain herniation. Patients with brain mass lesions, severe brain edema, and pneumocephalus were excluded. Age, gender, and ventricular size were not exclusion criteria.

Results

The mean patient age was 43.58 years (range 4-73), with 50 men and 50 women. The mean Evan’s index was 25.7 % (SD=4.38 %, range 10.2-41.0 %). No differences were found between the angles of EVD placement on either side (89.50±1.22 degrees on the right and 89.60±1.14 degrees on the left). Hence, nearly all EVD cases had been placed perpendicularly to the skull surface at a pinpoint location.

Conclusion

The proposed point of successful ventriculostomy placement in this study was 3 cm from the bregma along the coronal suture. The angle of EVD placement was approximately 90 degrees in almost all patients and was independent of the patient’s age and the side of the head that was entered. Little correlation was found between the value of the entry angle and Evan’s index. The point is simply identifiable, and its entry is easily accessible in practice.

[Surgical treatment of hemispheric and subcortical gliomas adjacent to corticospinal tract in children using MR tractography and intraoperative electrophysiological monitoring]

Difficult total resection of supratentorial gliomas adjacent to the corticospinal tract (CST) is due to the high risk of its injury and disability of patients. The main methods for preventing intraoperative CST damage are preoperative MR tractography and intraoperative electrophysiological monitoring. The problem of total resection of gliomas adjacent to the CST with preservation of high functional status is difficult due to immaturity and plasticity of brain structures in children. Moreover, the advantages of MR tractography combined with intraoperative monitoring have not been described. The authors present surgical treatment of supratentorial gliomas adjacent to the CST at different anatomical levels. Patients underwent preoperative and postoperative MR tractography and intraoperative electrophysiological monitoring. MR tractography provided preoperative data on CST lesion. Intraoperative monitoring made it possible to identify and preserve CST in the depth of surgical wound. MR tractography and intraoperative electrophysiological monitoring increase resection quality in patients with hemispheric and subcortical gliomas without postoperative functional deterioration.

[Neurosurgeon training: current problems and modern approaches]

Analysis of historical and modern approaches to teaching neurosurgery by professional communities and public authorities in the United States, the European Union and the Russian Federation makes it possible to develop a modern training program regarding content and duration. High-tech and dynamically developing specialty has acquired several large sub-specializations over the past decades. Each direction requires a long-term training and a special program. Training in neurosurgery in the modern world takes 5-7 years and involves acquisition of clinical and scientific knowledge. Some issues are brought up for discussion by professional community. Solution of these problems will provide an opportunity for international integration of the Russian training program for neurosurgeons. High level of neurosurgery in our country and a single educational space with the European community will allow exchanging students, adopting foreign experience and sharing our own experience.

[Surgical treatment of drug-resistant epilepsy following hippocampal sclerosis]

Surgery is an effective approach for drug-resistant temporal lobe epilepsy following hippocampal sclerosis. There is still no clear and unanimous opinion about advantages and disadvantages of certain surgical technique.

MATERIAL AND METHODS

There were 103 surgical interventions in 101 patients. Females prevailed (1.45:1). Age of patients ranged from 16 to 56 years (median 28). Anteromedial temporal lobectomy and selective amygdaloghippocampectomy were performed in 49 (47.6%) and 54 (52.4%) patients, respectively. In the latter group, 30 patients were operated via a 14-mm burr hole-subtemporal approach. Postoperative outcomes were assessed using the Engel grading system. The follow-up period ranged from 2 to 8 years (median 4 years).

RESULTS

By the 2^nd year, Engel class I was observed in 74 (72%) patients, Engel II, III and IV - in 20 (19.4%), 6 (5.8%) and 3 (2.9%) patients, respectively. Engel class I was achieved after anteromedial temporal lobectomy in 68% of cases, selective amygdaloghippocampectomy via standard approaches in 75% of cases, amygdaloghippocampectomy via subtemporal burr hole approach - in 80% of cases. Neurocognitive impairments after anteromedial lobectomy and selective amygdaloghippocampectomy were similar. At the same time, mental disorders de novo prevailed in the group of anteromedial lobectomy (p<0.05). There were no severe visual field disorders after subtemporal burr-hole access. In other cases, these disorders occurred in 36.2% of patients (p<0.05). There were 8 (7.8%) postoperative complications: 5 (10.2%) - after anterior temporal lobectomy, 3 (5.5%) - after selective surgeries via standard approaches. There were no complications after burr-hole surgery.

CONCLUSION

Selective amygdaloghippocampectomy is not inferior to anteromedial lobectomy. Moreover, this procedure is associated with a lower risk of complications and adverse events.

[Brainstem arachnoid cyst: case report and review]

There are no literature data on brainstem arachnoid cysts in humans.

OBJECTIVE

To describe the clinical case of brainstem (pontomesencephalic) arachnoid cyst and to analyze classification, pathogenesis, differential diagnosis and treatment of this pathology considering literature data and own experience.

MATERIAL AND METHODS

A 29-year-old patient with pontomesencephalic arachnoid cyst is reported. The disease manifested in childhood with a headache aggravated by bending and pushing. Later, syncope, vegetative-visceral paroxysms, mild oculomotor disturbances, transient paresthesia and numbness of the left half of the face occurred. Headaches became significantly more severe and resulted nausea and vomiting. Magnetic resonance imaging (MRI) revealed a two-chambered arachnoid cyst. A smaller chamber was localized in interpeduncular cistern, a larger one - in brainstem.

RESULTS AND DISCUSSION

Differential diagnosis included cystic glioma and Virchow-Robin space enlargement. Fenestration of the cyst wall within interpeduncular cistern was performed via right-sided pterional approach. The diagnosis was verified by histological examination. The follow-up period was 14 months. We observed postoperative cyst reduction confirmed by MR data and regression of all symptoms except for minimal signs of medial longitudinal fasciculus dysfunction.

CONCLUSION

Correct surgical approach for brainstem arachnoid cyst complicated by progressive neurological deterioration is confirmed by postoperative regression of cyst and symptoms.

[Hepatopulmonary syndrome: a rare manifestation of cirrhosis in patient with diencephalic obesity and nonalcoholic fatty liver disease after surgery for craniopharyngioma]

We describe a 15-year girl, who developed panhypopituitarism and diencephalic obesity after surgical excision of craniopharyngioma, followed by nonalcoholic fatty liver disease and cirrhosis 5 years after surgery. Cirrhosis in this case manifested by hypoxia due to hepatopulmonary syndrome, and despite cure of craniopharyngioma by surgery and radiosurgery treatment and adequate hormonal substitution therapy patient died 9 years after surgery. Growth hormone substitutional therapy in patients with hypopituitarism, and steatohepatitis may decrease liver triglyceride accumulation and prevent end-stage liver disease.

[Central neurocytomas: long-term treatment outcomes]

Central neurocytoma is a rare benign brain tumor. These tumors may be giant and accompanied by compression of ventricular system and surrounding structures. Modern treatment of brain neurocytoma includes extended resection and restoration of normal CSF circulation. Surgical treatment does not often lead to total resection of these tumors. Redo resection was preferred in patients with tumor progression for a long time. In the last decade, various authors report stereotactic irradiation for continued tumor growth to ensure local growth control. This study was aimed at evaluation of postoperative outcomes in patients with brain neurocytomas, as well as treatment of tumor progression in long-term period.

OBJECTIVE

To analyze recurrence-free survival in patients with brain neurocytomas, risk factors of recurrence-free survival, effectiveness of various treatments for tumor progression and delayed complications.

MATERIAL AND METHODS

Long-term postoperative follow-up data of patients with brain neurocytomas are reported in the manuscript. We analyzed recurrence-free survival and risk factors of recurrence-free survival, treatment outcomes in patients with progression of brain neurocytomas, long-term complications and their prevention.

RESULTS

Follow-up included 84 out of 115 patients with brain neurocytoma after surgical treatment in 2008-2017. Follow-up period ranged from 2 to 10 years (mean 6 years) after resection. Most patients had regression of neurological symptoms after surgery. Continued tumor growth within 12-96 months after surgery occurred in 26 (30.19%) out of 84 patients (19 cases after partial resection and 7 cases after total resection according to MRI data). Two-year recurrence-free survival was 94%, 5-year survival - 83%. Risk factors of continued tumor growth were resection quality and Ki-67 index. Redo resection was performed in 7 cases. Eleven patients underwent stereotactic irradiation for tumor progression. Indications for stereotactic irradiation of central neurocytoma are MR data on continued growth of lateral ventricle tumor without signs of ICH and CSF flow impairment. There were no cases of hemorrhage inside the residual tumor and CSF flow impairment in early postoperative period after redo resection. In all cases (n=11), stereotactic irradiation (mean follow-up 2.5 years) ensured satisfactory control of tumor growth with reduction of the neoplasm in 4 cases and no tumor growth in 7 cases.

CONCLUSION

Resection of central neurocytoma ensures long-term recurrence-free period. The main causes of tumor recurrence are partial resection and high proliferative activity (Ki-67 index over 5%). Redo resection is advisable for tumor progression followed by CSF flow impairment. In case of continued growth of neurocytoma without signs of intracranial hypertension, stereotactic irradiation with various fractionation modes ensures effective and safe control of tumor growth.

[Stereotactic irradiation in the complex treatment of patients with intracranial pilocytic astrocytoma]

Complex management of patients with intracranial pilocytic astrocytoma (PA) consists of surgical treatment, drug therapy (mainly in young children) and radiotherapy. For many years, radiotherapy (RT) has been a standard for residual tumors, recurrence or continued growth of PA. Currently, stereotactic radiosurgery and radiotherapy are preferred for PA, because these procedures are characterized by high conformity and selectivity, precise irradiation of tumor with minimal damage to surrounding intact tissues. Stereotaxic approach is very important since PAs are localized near functionally significant and radiosensitive brain structures in most cases. There is significant experience of single-center studies devoted to radiotherapy of patients with PA at the Department of Neuroradiosurgery of the Burdenko Neurosurgery Center. In this research, the authors analyzed the results of stereotactic irradiation of 430 patients with PA for the period from 2005 to 2018.

[Combination of pituitary adenomas and intracranial aneurysms]

The combination of intracranial tumors and asymptomatic brain aneurysms is an urgent problem, since it can significantly affect surgical intervention. Aneurysms are common in patients with meningioma, glioma and pituitary adenoma. According to certain authors, combination of aneurysms with pituitary adenomas is 7 times more common than with other tumors. In these cases, a comprehensive examination of the patient and decision-making on surgical strategy are required. This review is devoted to epidemiology, diagnosis and treatment of patients with a combination of pituitary adenomas and intracranial aneurysms detected intraoperatively or at the preoperative stage. The manuscript is illustrated by cases observed at the Burdenko Neurosurgery Center.

[«Cavernous angiomas» of the brainstem. Clinical manifestations, diagnosis and treatment results]

Introduction

In the current literature, brainstem hematomas and various types of vascular micromalformations are combined into the one group of diseases under the general name «cavernous angioma» (CA). This approach does not make it possible to accurately determine the indications for surgery and predict postoperative outcomes.

Objective

To analyze our own experience in the diagnosis and treatment of patients with the brainstem CA.

Material and methods

There were 515 patients with CA of the brainstem (surgery - 322, conservative treatment - 193 patients) with a follow-up period of more than 5 years. Follow-up survey implied neurological examination, analysis of Karnofsky score, MRI and CT data.

Results

We identified two main groups of patients after comparison of MRI data, intraoperative findings and biopsy data: group 1 - hematomas (191 patients, 59%), group 2 - CA (131 patients, 41%). Each group was characterized by own clinical and radiological features. Postoperative outcomes depended on the disease. Debridement of hematoma ensured early postoperative improvement in 63% of patients, no changes in 21% of cases and impairment in 16% of patients. Less favorable results were observed in patients with CA and no signs of hemorrhage. Clinical impairment occurred in 73% of cases, improvement - only in 5% of patients. The most significant regression of neurological symptoms in long-term postoperative period was observed in patients with hematomas (92% of patients). These ones noted much better clinical state compared with preoperative condition.

Conclusions

The type of brain lesion is an important predictor to determine treatment approach. Postoperative outcomes differ significantly in patients with the brainstem hematoma and CA.

[Central neurocytomas: surgical treatment outcomes and new trends and approaches in the treatment]

AIM

Central neurocytomas of the brain are rare benign tumors of the cerebral lateral ventricles. The main treatment for them is surgical resection. Resection provides a long-term relapse-free period, but surgical intervention is associated with a number of significant difficulties due to the location, size, and blood supply features of these tumors. The postoperative period is often accompanied by hemorrhagic complications, impaired cerebrospinal fluid circulation, and worsening of neurological symptoms.

PURPOSE

The study purpose was to evaluate the effectiveness of surgical treatment in neurocytoma patients, assess the risk of complications after neurocytoma resection, and develop techniques for their prevention.

MATERIAL AND METHODS

The paper presents surgical treatment outcomes in 115 patients with central neurocytomas for the period from 2008 to 2017. The choice of a surgical approach and the surgical features are described in detail, and the radicality is assessed with allowance for the location and size of tumors. The immediate clinical outcomes of treatment are evaluated, complications are analyzed, and methods for prevention and treatment of complications are described.

RESULTS

Analysis of the data revealed that the tumor was resected totally in 41 (36%) patients, subtotally - in 37 (32%), and partially in 37 (32%). The most common and dangerous complications were as follows: CSF circulation occlusion with the development of hydrocephalus in 23 (20%) patients; hemorrhage into the residual tumor, which required immediate revision of the surgical wound in most cases, in 25 (22%) patients. In the early postoperative period after tumor resection, almost all patients developed deterioration of condition with transient worsening of cerebral and focal symptoms. The degree and duration of this worsening were different. In 50% of cases, the postoperative condition was characterized by reduced voluntary activity, drowsiness or jitteriness, and motor or speech anxiety.

CONCLUSION

We consider resection of neurocytomas as the main treatment option, despite the potential complications and effects of the operation.

[Pseudoprogression of intracranial pilocytic astrocytomas and other low-grade gliomas. Literature review and case report]

Tumor pseudoprogression is characterized by temporary tumor enlargement following radiotherapy with subsequent stabilization or regression without additional treatment. This phenomenon has been comprehensively described in patients with malignant gliomas. However, this phenomenon has not been sufficiently studied in patients with low-grade gliomas including pilocytic astrocytomas. In recent years, more and more researches devoted to this problem have appeared in the literature. It seems relevant to conduct a meta-analysis of these data in the modern literature.

[Primary pineal melanocytoma: clinical case and literature review]

Primary pineal melanocytomas are extremely rare pathologies and predominantly are clinically manifested by nonspecific symptoms of a pineal affect, which could be characteristic for tumors of different histological nature located in the same region. Also these tumors differ from other melanocytic tumors by their slow growth and relatively favorable clinical prognosis.

[Oculomotor nerve neurinomas. Case reports and a literature review]

Oculomotor nerve neurinoma not associated with neurofibromatosis type II is an extremely rare pathology. According to the topography, cisternal, cisternocavernous, cavernous, orbitocavernous, and orbital tumor groups are distinguished. The clinical picture of the disease is characterized mainly by either oculomotor disorders or pyramidal symptoms, depending on the tumor localization. Neurinomas of the oculomotor nerve rarely occur without oculomotor disorders. However, in some patients with these tumors, the third nerve function remains intact. In this paper, we present clinical cases of two patients with oculomotor nerve neurinomas and analyze the relevant literature.

[Chiasm and optic nerve glioma manifested as hemorrhage (two clinical cases and a literature review)]

The article presents two rare clinical cases of low-grade (WHO grade I-II) glioma of the anterior visual pathway structures, the chiasm and optic nerves, in adults. The feature of these cases was the benign nature of a chiasm and optic nerve glioma in adults as well as its presentation in the form of hemorrhage to the tumor and parenchymal and subarachnoid space, which to some extent complicated making the correct diagnosis. Removal of an intracerebral hematoma and open tumor biopsy were performed in one case, and removal of a hematoma and partial tumor resection followed by radiotherapy were performed in the other case.

[Intracranial neurenteric cysts: experience of the Burdenko Neurosurgical Institute in the XXIth century]

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.

[Transient enlargement of craniopharyngioma cysts after stereotactic radiotherapy and radiosurgery]

Stereotactic radiotherapy/radiosurgery (RT/ES) is an effective technique for treating craniopharyngiomas (CPs). However, enlargement of the cystic part of the tumor occurs in some cases after irradiation. The enlargement may be transient and not require treatment or be a true relapse requiring treatment.

MATERIAL AND METHODS

In this study, we performed a retrospective analysis of 79 pediatric patients who underwent stereotactic RT or RS after resection of craniopharyngioma.

RESULTS

Five-year relapse-free survival after complex treatment of CP was 86%. In the early period after irradiation, 3.5 months (2.7-9.4) on average, enlargement of the cystic component of the tumor was detected in 10 (12.7%) patients; in 9 (11.4%) of them, the enlargement was transient and did not require treatment; in one case, the patient underwent surgery due to reduced visual acuity. In 8 (10.1%) patients, an increase in the residual tumor (a solid component of the tumor in 2 cases and a cystic component of the tumor in 6 cases) occurred in the long-term period after irradiation - after 26.3 months (16.6-48.9) and did not decrease during follow-up in none of the cases, i.e. continued growth of the tumor was diagnosed. A statistical analysis revealed that differences in the terms of transient enlargement and true continued growth were statistically significant (p<0.01).

CONCLUSION

Enlargement of a craniopharyngioma cyst in the early period (up to 1 year) after RT/RS is usually transient and does not require surgical treatment (except cases where worsening of neurological symptoms occurs, or occlusive hydrocephalus develops).

[MR tractography in diagnosis and choice of a neurosurgical approach to basal ganglia tumors]

We describe two cases of surgical treatment of well-circumscribed basal ganglia tumors. The choice of a neurosurgical approach to a deep tumor was based on the MR tractography data and depended on the course and dislocation extent of the corticospinal tract. MR tractography provides information on the course and dislocation or destruction extent of the corticospinal tract running in the internal capsule and brainstem and clarifies the exact location of a tumor within the basal ganglia. This information promotes the choice of an optimal approach for radical resection of well-circumscribed tumor, leading to improvement in neurological symptoms and patient's quality of life.

[Preoperative and postoperative ophthalmic symptoms in patients with space-occupying lesions of the midbrain and pineal region]

The most common clinical manifestations of space-occupying lesions of the midbrain and pineal region are oculomotor and pupil disorders and ophthalmoscopic signs of intracranial hypertension.

PURPOSE

To identify patterns of neuro-ophthalmic symptoms before and after surgical treatment in patients with space-occupying lesions of the midbrain and pineal region.

MATERIAL AND METHODS

We analyzed neurological symptoms in 231 patients with space-occupying lesions of the midbrain and pineal region before and after surgical treatment. Malignant tumors were detected in 121 patients; benign tumors were present in 73 patients; 37 patients were diagnosed with pineal gland cysts. Patients with suspicion of germinoma underwent a tumor biopsy only; the other patients underwent tumor resection.

RESULTS AND DISCUSSION

Before surgery, oculomotor and pupil disorders were detected in more than half of the (67%) patients; ophthalmoscopic signs of intracranial hypertension were present in 38% of the patients. Neuro-ophthalmic symptoms significantly more often occurred in patients with malignant tumors. Midbrain symptoms were significantly more pronounced in germ cell tumors than in other malignant neoplasms. In the early postoperative period after tumor resection, deterioration of oculomotor and pupillary functions occurred in 46% of cases; there were no changes in 51% of cases; improvement occurred in 3% of cases. After tumor biopsy, symptoms in all patients with germinomas remained at the preoperative level. Developed symptoms partially regressed in the long-term period, and finally, only 29% of patients had deterioration of oculomotor and pupillary functions compared to the preoperative level.

[Severe postoperative intracranial hemorrhagic complications in a neurosurgical patient with von Willebrand disease not diagnosed before surgery (a case report and literature review)]

The article describes a rare clinical case of a patient with previously undiagnosed von Willebrand disease and basal meningioma; an intracranial neurosurgical intervention was complicated by delayed intracranial hematomas, both at the resected tumor site and distantly. The diagnosis of von Willebrand disease was established only after special hematology tests and only after surgery. Despite the use of specific therapy, the patient died due to intracranial hemorrhagic complications in the postoperative period. The paper discusses the problem of preoperative diagnosis of asymptomatic hemostasis disorders in neurosurgical patients and potential ways of its solution.

[A rare case of diencephalic cachexia in an adult female with cranio-pharyngioma]

Diencephalic cachexia (DС) is progressive weight loss despite a normal caloric intake and a satisfactory state of health, which is caused by hypothalamic lesions. This is a rare (about 100 cases were reported) and potentially fatal disorder of unknown pathogenesis. At present, there is no effective pharmacological therapy for the disorder. Cachexia may regress only if the tumor reduces in size, therefore the timely diagnosis and treatment are of vital importance for the patient. DС is typical of early childhood, and only a few cases have been reported in adults. We present a rare case of DС in a 24-year-old female with papillary craniopharyngioma.

[Gene mutations in patients with hereditary cavernous malformations]

AIM

To identify mutations in cerebral cavernous malformation (CCM) genes in patients with hereditary and sporadic CCMs in the Russian population.

MATERIAL AND METHODS

Blood samples from 73 randomly selected patients, including 29 MRI-confirmed familial cases, 8 clinically confirmed familial cases and 38 so-called sporadic cases, were examined. A search for large deletions/duplications was performed using multiplex ligation-dependent probe amplification (MPLA). For MLPA-negative samples, the whole genome sequencing was performed to search for single nucleotide polymorphisms (SNP).

RESULTS

Deletions in three genes (ССМ1, ССМ2, ССМ3) were identified in 14 patients, including 5 without definitely established familial type, in whom the familial character of disease was not confirmed by clinical and neuroimaging results. SNP mutations were found in 13 patients, CCM gene mutations in 27. Mutations were detected in 91.7% of familial cases. In two patients, new CCM3 deletions were identified. Gene distribution was as follows: 60.7 for CCM1, 32.2 for CCM2 and 7.1% for CCM3. In two members of a family with hereditary CCMs, no high effect mutations in the known CCM genes were found. Patients with mutations had greater severity of disease. Two patients with CCM3 mutations demonstrated the most aggressive clinical course. De novo formation and growth of CCM were observed only in patients with mutations.

CONCLUSION

The distribution of pathogenic mutations in known CCM genes is consistent with other large-scale studies. Familial CCMs are associated with more severe disease course and may be caused by mutations beyond the known CCM genes.

[A clinical and neuropsychological study of patients before and after resection of third ventricle colloid cysts]

The literature lacks studies of cognitive impairments in large groups of patients after resection of third ventricle colloid cysts.

AIM

To evaluate cognitive impairments in patients before and after resection of third ventricle colloid cysts.

MATERIAL AND METHODS

We performed a clinical and neuropsychological study of 52 patients with third ventricle colloid cysts using the Luria method (1962). Forty three patients were examined before and after cyst resection in the early postoperative period (three patients in this group were also examined in a long-term period of 3-7 months after surgery). Forty one patients were operated on using the transcallosal approach, and two patients were operated on using the subtentorial-supracerebellar transchoroidal approach. The other patients were examined only before or after surgery. The patients' age ranged from 14 to 61 years; the mean age was 33.8 years; the median age was 29 years.

RESULTS

On examination before surgery, cognitive impairments were minimal in 5 patients without clear signs of hydrocephalus. Impairments of memory and dynamic praxis, mild spatial disorders, and psychological inertia were observed in other patients with hydrocephalus. There was no significant difference in the state of cognitive functions between patients with and without stagnation in the fundus. On examination on day 3-6 after transcallosal surgery, several groups of patients were identified. Eight patients had an improvement in cognitive functions, which might be related to postoperative resolution of hydrocephalus. In 15 patients, changes in mnestic functions were insignificant. This group consisted of the youngest patients with a median age of 24 years. Korsakoff syndrome and disorientation were detected in 5 patients. This was the oldest age group, with a median age of 48 years. In other 13 patients, aggravation of mnestic disorders was moderate. Similar memory impairments were detected in the case of the subtentorial-supracerebellar approach. Memory disorders progressively regressed in all patients.

CONCLUSION

Postoperative memory impairment of a varying degree was found in 21 out of 43 patients, with adhesions between the cyst capsule and fornix being observed only in 5 patients. In this case, no injury to the fornix was intraoperatively observed. We discuss the role of the age factor, cyst size, and technical surgical difficulties in the pathogenesis of memory disorders in the absence of injury to the calvarium during colloid cyst resection.

[Application of intraoperative electromagnetic frameless navigation in transcranial and endoscopic neurosurgical interventions]

The paper summarizes the experience in using a system of electromagnetic intraoperative frameless navigation in various neurosurgical pathologies of the brain. The electromagnetic navigation technique was used for 102 operations in 98 patients, including 36 transnasal endoscopic interventions. There were no intraoprtative and postoperative complications associated with the use of the system. In the process of using the system, factors influencing the accuracy of navigation and requiring additional control by the surgeon were identified.

PURPOSE

The study purpose was to evaluate the use of electromagnetic navigation in surgical treatment of patients with various brain lesions.

MATERIAL AND METHODS

The system of electromagnetic navigation was used for 102 operations in 98 patients (42 males and 56 females, including 18 children; median age, 34.8 years (min, 2.2 years; max, 69 years)) in the period from December 2012 to December 2016. In 36 patients, the system was used for endoscopic interventions. In 19 patients, electromagnetic navigation was used in combination with neurophysiological monitoring.

RESULTS

In our series of cases, the frameless electromagnetic navigation system was used in 66 transcranial operations. The mean error of navigation was 1.9±0.5 mm. In 5 cases, we used the data of preoperative functional MRI (fMRI) and tractography for navigation. At the same time, in all 7 operations with simultaneous direct stimulation of the cortex, there was interference and significant high-frequency noise, which distorted the electrophysiological data. A navigation error of more than 3 mm was associated with the use of neuroimaging data with an increment of more than 3 mm, image artifacts from the head locks, high rate of patient registration, inconsequence of touching points on the patient's head, and unsatisfactory fixation to the skin or subsequent displacement of a non-invasive localizer of the patient. In none of the cases, there was a significant effect of standard metal surgical tools (clamps, tweezers, aspirators) located near the patient's head on the navigation system. In two cases, the use of massive retractors located near the patient's localizer caused noise in the localizer and navigation errors of more than 10 mm due to significant distortions of the electromagnetic field. Thirty-six transnasal endoscopic interventions were performed using the electromagnetic frameless navigation system. The mean navigation error was 2.5±0.8 mm.

CONCLUSION

In general, electromagnetic navigation is an accurate, safe, and effective technique that can be used in surgical treatment of patients with various brain lesions. The mean navigation error in our series of cases was 1.9±0.5 mm for transcranial surgery and 2.5±0.8 mm for endoscopic surgery. Electromagnetic navigation can be used for different, both transcranial and endoscopic, neurosurgical interventions. Electromagnetic navigation is most convenient for interventions that do not require fixation of the patient's head, in particular for CSF shunting procedures, drainage of various space-occupying lesions (cysts, hematomas, and abscesses), and optimization of the size and selection of options for craniotomy. In repeated interventions, disruption of the normal anatomical relationships and landmarks necessitates application of neuronavigation systems in almost mandatory manner. The use of electromagnetic navigation does not limit application of the entire range of necessary intraoperative neurophysiological examinations at appropriate surgical stages. Succession in application of neuronavigation should be used to get adequate test results.

[Surgical management of venous compression causing trigeminal neuralgia]

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.

[Supracerebellar transtentorial approach to tumors of the posterior portions of the medial temporal region]

OBJECTIVE

Despite the advances in microsurgery, the choice of the most adequate approach to the posterior part of the medial temporal region (MTR) remains a very controversial issue. The supracerebellar transtentorial approach (STA) is considered as the most preferable one, since it provides the optimal balance between retraction, incision, and resection of the brain tissue. Here, we present our consecutive series of 20 patients who underwent STA surgery.

MATERIAL AND METHODS

Twenty patients with glial tumors affecting the posterior MTR underwent STA surgery between 2006 and 2014. The mean age of the patients was 20 years. Benign tumors were predominant (18 out of 20 cases).

RESULTS

Resection of the posterior and middle MTRs was conducted in 16 cases. The anterior MTR was accessed through STA in 1 patient only; in 2 patients, STA was combined with the infraoccipital approach. Cerebellar edema occurred in 4 patients, with hemiparesis persisting in one of the cases for 1 year after surgery. Of 8 patients with drug resistant epilepsy, the Engel class 1 or 2 outcome was achieved in 6 cases within 1 year after surgery.

CONCLUSION

STA provides an excellent surgical route to the posterior and middle MTR portions; however, the anterior MTR portions cannot be reached safely. The operative risks of STA increase as the surgeon proceeds with resection of the anterior MTR portions. Anterior MTR structures can be removed using a combination of the supracerebellar and infraoccipital transtentorial approaches or two-stage resection.

A giant hyperostotic parasagittal meningioma in a child with neurofibromatosis type II (a case report and literature review)

Large parasagittal meningiomas, in particular hyperostotic ones, in children are rare and problematic in the differential diagnosis. The literature reports only single clinical cases related to this issue; opinions about the indications, surgical treatment options, and prognosis are contradictory. This paper presents a clinical case of a hyperostotic parasagittal meningioma with intra-extracranial growth in a 10-year-old boy with neurofibromatosis type II significantly worsening the prognosis. We discuss the epidemiological and clinical features of childhood meningiomas and issues of their diagnosis, treatment, and prognosis.

Basal ganglia germinomas in children. Four clinical cases and a literature review

Basal ganglia germinomas are a specific group of intracranial germinomas. Their early diagnosis is complicated due to their atypical localization and diversity of neuroimaging and clinical signs.

MATERIAL AND METHODS

We describe 4 cases of basal ganglia germinoma in boys of 13, 14, 15, and 16 years of age. The medical history data, clinical features, neuroimaging and histological characteristics of basal ganglia germonomas, and preliminary results of the treatment are presented.

CONCLUSION

Basal ganglia germinomas are usually verified at the late stage of the disease when patients are detected with extended lesions of the basal ganglia and severe neurological and neuroendocrine deficits. This situation is due to clinical and imaging signs that are untypical of common germinomas.

[Decompressive craniotomy in patients with intracranial aneurysmal hemorrhage]

Decompressive craniotomy (DCT) has been used for treatment of patients with acute aneurysmal subarachnoid hemorrhage (SAH) for more than 20 years. But so far, the attitude to this surgery is controversial, and the indications and contraindications for it are not clearly defined. The article reviews the domestic and foreign literature devoted to the issues of validity and efficacy of DCT in treatment of cerebral edema and intracranial hypertension in patients with aneurysmal SAH.

[Surgical treatment of cerebral vascular diseases]

Theoretical and practical aspects of the complex treatment of brain and spinal vascular diseases using microsurgical, endovascular and radiosurgical methods are considered. Authors present the data demonstrating that, due to the implementation of the program of development of vascular centers in the Russian Federation, considerable progress was made in the treatment of cerebral aneurisms and hemorrhagic stroke. In author's opinion, wide introduction of surgical methods in the treatment of occlusive lesions of the blood vessels supplying the brain is needed.

[Combined treatment of cerebral arteriovenous malformations. Experience of the Burdenko Neurosurgical Institute]

OBJECTIVE

Despite the achievements of recent years, cerebral AVMs continue to pose a challenge to treatment. The objective of this work was the development of recommendations for combined treatment of AVMs based on analysis of the available material and published data.

MATERIAL AND METHODS

The study included 93 patients hospitalized at the Neurosurgical Institute for combined treatment of cerebral AVMs in 2010-2014. A group of combined surgery (removal of an AVM with preoperative embolization) consisted of 40 patients, and a group of combined radiotherapy (radiation after partial embolization or partial removal of an AVM) included 53 patients. 36 patients underwent radiosurgery, and 17 patients received stereotactic radiation therapy. Both groups were analyzed in terms of outcomes, complications, and follow-up results.

RESULTS

In the group of combined surgery, according to the Glasgow outcome scale, good results (grade 4-5) were achieved in 35 (87.5%) patients at discharge and in 27 (90%) patients during follow-up. Treatment outcomes, surgery duration, and the amount of blood loss were not significantly different from those in the control group. Complete AVM obliteration was achieved in 29 (80.6%) patients 3 years after radiosurgery and in 8 (47%) patients after stereotactic radiotherapy. In discussion, these findings are compared to the published data, and recommendations for AVM treatment are suggested.

CONCLUSION

The combined treatment of AVMs is effective management for patients with complex AVMs (Spetzler-Martin grade III-IV AVMs). Successful treatment of AVMs requires careful planning and teamwork of vascular and endovascular neurosurgeons, radiologists, and neurologists.

[Growing teratoma syndrome in a patient with intracranial germ cell tumor]

A six-year-old patient with non-germinomatous germ cell tumor of the chiasmatic-sellar area developed polyuria and polydipsia as the first symptoms of the disease. Then there were signs of precocious puberty and vision impairment. MRI examination revealed a shiasmatic sellar tumor and occlusive hydrocephalus. Tumor marker levels in blood serum were elevated. The alpha-fetoprotein level was increased 5-fold; human chorionic gonadotropin 20-fold. These levels increased over time. The patient received 2 cycles of PEI multiagent chemotherapy (Ifosfamide 1.5 g/m(2), Cisplatin 20 mg/m(2), Etoposide 100 mg/m(2)) during 5 days and 1 cycle of second-line multiagent chemotherapy (Cisplatin 100 mg/m(2) for 1 day and Endoxan 1500 mg/m(2) for 2 days). Despite the decrease in tumor marker levels to normal values, the patient's vision still deteriorated. MRI examination revealed that tumor size increased and its structure changed. Total tumor resection led to vision improvement and regression of intracranial hypertension. Histological analysis of tumor tissue only revealed a mature teratoma. This phenomenon, known as growing teratoma syndrome, is very rare among patients with intracranial non-germinomatous germ cell tumors.

[The outcomes of stereotactic radiotherapy in patients with cerebral arteriovenous malformations]

INTRODUCTION

Cerebral arteriovenous malformations (AVMs) are the congenital anomalies of development of cerebral vessels during the embryonic period. The conventional therapy for AVMs currently includes endovascular management, microneurosurgical resection, and stereotactic irradiation.

MATERIAL AND METHODS

A total of 315 patients with brain AVMs were subjected to stereotactic radiotherapy in 2005-2011. 238 (76%) patients had previous subarachnoid hemorrhage (SAH) within different time (6 months to 5 years) before the therapy; 214 (68%) patients had headaches; 113 (36%) patients had focal neurological symptoms caused by localization; and 82 (26%) patients had seizures. Twenty-three patients were subjected to surgical resection of an intracerebral hematoma prior to radiotherapy and 119 (36%) patients received endovascular treatment including partial embolization of the stroma of AVM. 267 patients received single-fraction radiosurgical irradiation. In patients with large AVMs, we used the hypofractionation technique consisting in target irradiation with several (usually 2-7) fractions; the radiation dose per fraction exceeds 2 Gy. Forty-six patients were irradiated in the hypofractionation mode; two patients had a course of stereotactic radiotherapy in the standard fractionation mode. The marginal dose of radiosurgical irradiation was 13-30 Gy (the average dose was 24 Gy). The main group of patients (38 individuals) with large AVMs was treated using hypofractionation of 35 Gy per 5 fractions.

RESULTS

Control angiography was carried out in 225 patients who had been followed up for at least 2 years after therapy showed that complete obliteration was achieved in 83% of cases. The rate of symptomatic radiation reactions was less than 10%. The higher risk of developing obliteration was observed for AVMs less than 2 cm3 in size at marginal doses more than 24 Gy. In the hypofractionation group consisting of 27 patients with complete follow-up data, obliteration was observed in 10 (37%) patients. The rate of symptomatic reactions was less than 35%.

CONCLUSIONS

The radiosurgical method is a minimally invasive choice of treatment for patients with brain AVM, which allows one to achieve sufficiently high degree of obliteration with the minimum complication rate. The hypofractionation procedure is the method of choice for treating large AVMs. Stereotactic irradiation using the Novalis linear accelerator makes it possible to treat patients with AVMs of virtually any location and volume.

Multiple primary liponeurocytoma of the central nervous system

We report a unique case of primary multiple liponeurocytoma. Liponeurocytoma is a rare benign tumor (Grade II) of the posterior cranial fossa with neural- or probably astrocytic-lineage cells; the tumor stroma contains mature adipocytes. This case is the thirty-eighth case of this pathology reported in the world literature and the first case of multiple form of this disease. We have provided a sufficiently thorough neuroradiological and histological picture that allows one to differentiate between a liponeurocytoma and other histological variants. Recommendations for the tactics for managing patients with this rare disease are proposed based on the analysis of treatment of this pathology reported in the world literature.

Experience of surgical management of trigeminal schwannomas that simultaneously spread to the middle and posterior cranial fossae

INTRODUCTION

trigeminal schwannomas account for 0.07-0.36% of all intracranial tumors and 0.8-8% of all intracranial schwannomas. Different surgical approaches are used depending on the topographic anatomical variant of the tumor. Dumbbell-shaped tumors that spread both to the middle and posterior cranial fossae are the most challenging ones in terms of their resection.

MATERIAL AND METHODS

Five patients with dumbbell-shaped trigeminal schwannomas were operated on at the Burdenko Neurosurgical Institute in 2011-2013. In four cases, tumor resection comprised two stages using the retrosigmoid suboccipital approach (RSA) and lateral extended transsphenoidal endoscopic approach (LETEA); in one case, the tumor was resected in a single session through the LETEA. If there were pronounced symptoms affecting the brainstem and/or cerebellum, tumor resection from the posterior cranial fossa through RSA was resected at the first stage (3 cases). If no symptoms were observed, tumor resection from the middle cranial fossa through LETEA was used as the first stage (2 cases).

RESULTS

After two surgical stages, total, subtotal, and partial tumor resection was performed (one case each). Total tumor resection from the middle cranial fossa was achieved through LETEA in two cases. Aggravation of ipsilateral paresis of the craniocerebral nerve VI was observed after the surgery in two cases. No cases of nasal liquorrhea were observed after transnasal surgery. In one case, the cavernous segment of the internal carotid artery was damaged during LETEA, thus requiring endovascular occlusion of the damaged vessel to be performed.

CONCLUSION

LETEA is an effective approach that allows resection of tumors from the middle cranial fossa and the cavernous sinus. Combined with RSA, this approach can be used for two-stage resection of dumbbell-shaped trigeminal schwannomas.

[Modern molecular approaches to diagnosis and treatment of high-grade brain gliomas]

The review analyzes the current state of the problem of diagnosis and therapy of high-grade gliomas on the basis of the most promising present-day approaches. The diagnostic and treatment perspectives of the molecular genetic analysis of glioblastoma markers located on the tumor cell surface are considered. Gene therapy and the use of dendritic cells and oncolytic viruses are considered as the most interesting approaches to therapy of high-grade gliomas.

Transsphenoidal surgery of craniopharyngioma: form palliative surgery to radical removal

The paper presents basic principles of transsphenoidal craniopharyngioma surgery. Stages of methodology development. Steps of methodology development of such operations in the Institute are described--from palliative interventions to the high-tech modern radical surgery with the use of anterior extended approach. Additional stereotactic irradiation provides reliable control of the disease for a long period. The article mainly describes operative technique and contains preliminary analysis of the surgical results showing effectiveness and safety of endoscopic removal of craniopharyngioma.

Radiosurgical irradiation of patients with cerebral AVM on the Gamma knife

Arterio-venous malformation (AVM) of the brain are congenital malformations of cerebral vessels in the embryonic period. Standards in AVM treatment is currently applying the endovascular technique, microneurosurgical removal and stereotactic radiation.

MATERIALS AND METHODS

In the period from 2005 to 2011, in 139 patients with arteriovenous malformations of the brain were treated using "Gamma Knife". 89 (64%) of 139 patients suffered bleeding in anamnesis. Paroxysmal symptoms of varying severity dominated in the clinical picture of 35 (27%) patients. Previous microsurgical resection was performed in 10 patients. 28 patients experienced a partial embolization of vascular malformations before radiosurgery. A boundary value radiation dose ranged from 18 to 28 Gy (mean dose 20 Gy), day dose was in the range of 40-80% (average 50% isodose). Maximum dose ranged between 18-60 Gy (mean dose of 38 Gy.).

RESULTS

Control angiography or spiral CT screening angiography was performed in all 85 patients who were treated with follow-up data for more than two years, showed that total obliteration occurred in 75% of cases. Frequency of symptomatic radiation reactions was less than 5%. After two years or more after treatment, complete obliteration was observed in 74% of patients.

CONCLUSIONS

Higher frequency of AVM obliteration was seen with up to 2 cc. and the irradiation dose of at least 24 Gy.

Temporal transchoroidal approach for tumors of the midbrain and thalamus

Surgical approach to the tumors of deep localization depends on the predominant direction of tumor growth. The main task of the surgeon in such cases is to choose less traumatic approach with a sufficient angle of operational action to achieve greater surgical radicality. The article describes temporal transchoroidal approach to the tumors of the midbrain, thalamus, and optic tract. This approach in selected cases allows to remove deep-seated tumors with less damage compared with pterional and subtemporal approach.

Meningioma challenge: analysis of 80-year experience of Burdenko Neurosurgical institute and future perspectives

The paper describes the history of meningioma surgery at Burdenko Neurosurgical Institute, analyses of accumulated series of patients and assesses effectiveness of different techniques for meningioma diagnosis and treatment of. We analyzed 15413 patients with meningiomas operated in Burdenko Neurosurgical Institute from 1932 to 2011. Mathematical analysis was performed using Statistica 6.0 program. Mortality rate during World War II reached a disastrous level of 45,8%, in 21st century it is below 1%. Temporary and permanent morbidity has also decreased. While in 1961 Karnofsky performance score was 71, in 2011 it became 83. The probability of postoperative tumour recurrence also diminished, from 40% in 1960-s to 29% in 1996 and presumably to 25% nowadays. Independent factors that influence the risk of recurrence are primary gross total resection, grade of anaplasia and radiation therapy. However, unreasonably aggressive surgery leads to significant increase of morbidity. Further improvement of surgical results in patients with meningiomas depends on implementation of new technologies for neurovisualization, abandoning extensive surgical approaches whenever possible, finding the "balance" between radical removal and expected functional outcome, wider application of radiosurgery and three-dimensional conformal radiation therapy.

Intraparenchymal brainstem schwannomas: report of three cases and literature review

We report three patients with intraparenchymal brainstem schwannomas that were confirmed by surgery and pathological examination: tumors originated from the midbrain parenchyma, the dorsal aspect of the pontomedullary junction and the medulla oblongata respectively. Two of the presented patients differed in age of disease presentation which may reflect different mechanisms of tumor development according to the current views on origin of intraparenchymal schwannomas. One of the cases illustrates treatment of non-communicating hydrocephalus associated with ventricular tumors by preventive stenting of the cerebrospinal fluid pathways.

[Diffuse bithalamic astrocytomas in children and adults]

Diffuse bithalamic glioma is rare entity. A few cases have been described so far. We present the data of 13 patients (both children and adults) with diffuse bithalamic gliomas observed and treated at Burdenko Neurosurgery Institute within the period of 2004-2011. Age of patients varied from 3 to 29 y.o. Bithalamic gliomas appear as symmetric enlargement of both thalami on MRI with frequent spreading to adjacent structures (brainstem, temporal lobes). Histologically they appear as astrocytomas (Grade II-IV). Bithalamic gliomas posess different clinical course. There is no indication for surgical treatment because of diffuse growth of these tumors. Stereotactic biopsy is indicated to verify histological origin. Treatment of bithalamic gliomas confined with radio- and chemotherapy. In cases with obstructive hydrocephalus CSF diverting operations are indicated. Attempts of surgical excision lead to worsening of patient's neurological condition. Most patients with bithalamic gliomas have unfavorable prognosis. Tumors remain stable with adjuvant therapy for a very short period of time in most cases. Benign course of this pathology with long-term follow-up is observed only in a few cases.

[Implantation metastasizing of craniopharyngioma]

The paper describes two cases of implantation metastasizing of craniopharyngioma after its resection using combined (transcallosal and subfrontal) and pterional approach. The mechanisms of metastasizing and possible ways of prevention are discussed.