[Genetic factors in degenerative disc disease]. / Rol' geneticheskikh faktorov v razvitii degenerativno-distroficheskogo porazheniya mezhpozvonkovykh diskov.

OBJECTIVE: To analyze available literature data on the role of genetic factors in degenerative disc disease. METHODOLOGY: We reviewed the PubMed, MEDLINE, Cohrane Library, e-Library databases using the following keywords: degenerative spine lesions, intervertebral disc herniation, pathogenesis, genetic regulation. RESULTS: Searching depth was 2002-2022. We reviewed 84 references. Exclusion criteria: duplicate publications, reviews without detailed description of results, opinions. Finally, we included 43 the most significant studies. CONCLUSION: There are literature data on proinflammatory cytokines, growth factors and osteodestructive processes in pathogenesis of degenerative disc disease. However, there is only fragmentary information about the role of genetic regulation of these processes. Some factors, such as microRNA, TGF-b, VEGF, MMP are still poorly understood.

[Bullet embolism of internal carotid artery. (A case report and literature review)]. / Pulevaya emboliya vnutrennei sonnoi arterii. (Klinicheskoe nablyudenie i obzor literatury).

Bullet vascular embolism is a rare complication of gunshot wounds with risk of dire consequences and even death. Bullet embolism of internal carotid artery is extremely rare. Therefore, there is no uniform approach to the treatment of these patients. Nevertheless, removal of embolus through available surgical approach and arterial reconstruction with restoration of blood flow seems optimal. The authors present a 14-year-old patient with a wound to the left half of the chest from pneumatic gun complicated by bullet migration to the right ICA. Surgical intervention made it possible to remove the bullet from the artery and eliminate the risk of thrombosis and embolism. This case demonstrates the possibilities of open reconstructive surgery of supra-aortic vessels.

[Surgical treatment of cervical neurovascular bundle tumors]. / Khirurgicheskoe lechenie bol'nykh s opukholyami sosudisto-nervnogo puchka shei.

OBJECTIVE: To determine the main principles of a patient-oriented individual approach to diagnosis and surgical treatment of cervical neurovascular bundle tumors considering the capabilities of neurosurgical hospital. MATERIAL AND METHODS: There were 92 patients with cervical soft tissue tumors affecting neurovascular bundle. Age of patients ranged from 9 to 81 years (mean 47). There were 65.1% women and 34.9% men. We found chemodectoma (47.4%), neurofibroma (15.8%), neurinoma (13.2%), papillary thyroid cancer (5.3%), salivary gland heterotopia (5.3%), salivary gland adenocarcinoma (5.3%), Hodgkin lymphoma (2.6%), hemangioendothelioma (2.6%) and cavernous lymphangioma (2.6%). Diagnostic algorithm included neurological examinations, Doppler ultrasound of supra-aortic arteries, transcranial ultrasound of cerebral vessels, MRI of cervical soft tissues, CT-AG, MR-AG, CT-perfusion, direct selective angiography. RESULTS: A total of 94 surgical interventions were performed. All surgeries were performed using surgical optics and neurophysiological monitoring of cranial nerves IX, X, XII. We chose resection technique depending on localization, histological features and blood supply of tumor. En-bloc resection was performed in 46 cases, removal of fragments - in 23 cases, intracapsular resection of tumor followed by resection of the capsule - in 26 cases. Total and subtotal resection was performed in 68 (72%) and 23 (24%) cases, respectively. Three (4%) patients underwent partial resection of infiltrative tumors for carotid artery decompression and histological analysis. In 76% of cases, baseline symptoms of disease regressed after surgery. Persistent moderate bulbar disorders were observed in 16 patients (17%). Ischemic complications with additional surgical interventions were observed in 2 cases. CONCLUSION: Patients with cervical soft tissue tumors require individual approach regarding choosing the optimal surgical treatment including possible preoperative embolization of tumor, en-bloc or intracapsular resection and carotid artery repair.

[Complicated course of the postoperative period with the development of epidural hygroma and intracranial hypotension after removal of cranio-orbital meningioma. Clinical case and literature review]. / Oslozhnennoe techenie posleoperatsionnogo perioda s razvitiem epidural'noi gigromy i vnutricherepnoi gipotenzii posle udaleniya kranioorbital'noi meningiomy. Klinicheskii primer i obzor literatury.

Surgical removal of cranio-orbital meningiomas is an effective method of treating this pathology. Modern surgical techniques and technologies make it possible to perform operations with a low risk of complications. Lumbar drainage or repeated lumbar punctures are often used intraoperatively or in the early postoperative period to prevent nasal CSF leak; this rarely leads to the development of significant neurological symptoms. We present a case of the development of severe intracranial hypotension with the formation of a subdural hygroma in the early postoperative period after removal of a cranio-orbital meningioma in a 41-year-old patient. The operation was performed using an individual model and molds for simultaneous reconstruction of the bone defect with an implant made of polymethyl methacrylate. On the 1st and 2nd days after surgery, lumbar punctures were performed. From the 2nd day there was a progressive deterioration with the development of symptoms characteristic of intracranial hypotension. Computed tomography revealed an increasing displacement of the midline structures of the brain and an increasing volume of epidural fluid accumulation in the area of surgical intervention. Magnetic resonance imaging revealed characteristic signs of intracranial hypotension. Conservative treatment (bed rest, active hydration) had no effect. On the 6th day after surgery, an epidural blood patch procedure was performed and closed external drainage of the epidural hygroma was performed, and a rapid regression of neurological symptoms was noted. Our experience and literature data indicate that it is necessary to remember the possibility of developing clinically significant intracranial hypotension even after a single lumbar puncture. The formation of hygromas in the surgical area is characteristic of intracranial hypotension, but in most cases does not require additional surgical intervention and does not have a negative impact on the outcome of treatment. Conservative treatment of intracranial hypotension is the first choice and often sufficient. If there is no effect and the patient's condition worsens, it is necessary to perform an epidural blood patch procedure.

Сell clusters isolation in glioblastomas and their functional and molecular characterization using new morphometric approaches.

BACKGROUND: Digital pathology has come a long way in terms of creating tools to improve existing diagnostic approaches. However, several pathology fields, such as neuropathology, are still characterized by low coverage from machine learning tools and neural network analysis, which may be due to the complexity of the internal cellular and molecular structure of the corresponding neoplasms, including glioblastomas. METHOD: In the framework of this study, using advanced proprietary tools for obtaining images of histological slides and their deep morphometric analysis, we studied samples of 198 patients with glioblastoma with the selection of morphometric cell clusters. Also, cells of each cluster were isolated, and their proliferative, migratory, invasive activity, survival ability, aerobic glycolysis activity, and chemo- and radioresistance were studied. RESULTS: Four morphometric clusters were identified, including small-cell cluster, paracirculonuclear cluster, hypochromic cluster, and macronuclear cluster, which significantly differed in morphometric parameters and functional parameters. Hypochromic cluster cells demonstrated the highest proliferation activity; macronuclear cluster was the most active glucose consumer; paracirculonuclear cluster had the most prominent migratory and invasive activity and hypoxia resistance; small-cell cluster demonstrated predominantly average values of all parameters. Moreover, additional analysis revealed the presence of a separate subcluster of stem cell elements that correspond in their molecular properties to glioma stem cells and are present in all four clusters. It also turned out that several key molecular parameters of glioblastoma, such as mutational modifications in the EGFR, PDGFRA, and NF1 genes, along with the molecular GBM subtype, are significantly correlated with the identified cell clusters. CONCLUSIONS: Thus, the results represent an up-and-coming innovation in the practical field of digital pathology and fundamental questions of glioma carcinogenesis.

[The first application of intraoperative mri for analysis of cerebral perfusion in surgical brain revascularization]. / Pervoe primenenie intraoperatsionnoi MRT dlya issledovaniya tserebral'noi perfuzii pri khirurgicheskoi revaskulyarizatsii golovnogo mozga.

BACKGROUND: Effectiveness of surgical revascularization in patients with chronic cerebral ischemia depends on restoration of circulation in the damaged artery. Modern methods do not take into account dynamic changes in cerebral perfusion after extra-intracranial microvascular anastomosis (EICMA) and do not allow timely localizing the areas of persistent perfusion deficit. We propose a new method for determining the tactics of surgical cerebral revascularization based on intraoperative MRI (iMRI) perfusion data. This method provides the earliest information on intraoperative brain reperfusion. OBJECTIVE: To develop the principles of dynamic assessment of cerebral blood flow using intraoperative ASL perfusion during surgical revascularization in patients with chronic cerebral ischemia and to determine the indications for additional anastomoses. MATERIAL AND METHODS: Surgical revascularization with intraoperative MRI perfusion was performed in 27 patients between March 2022 and April 2023. There were 10 patients with post-thrombotic occlusion of internal carotid artery, 4 patients with occlusion of middle cerebral artery and 13 patients with moyamoya disease. All patients underwent MRI before surgery. After imposing the first EICMA, all patients underwent ASL perfusion for analysis of residual hypoperfusion zones, signs of local hyperperfusion and indications or contraindications for additional revascularization with the second donor branch. RESULTS: In all cases, iMRI made it possible to determine the tactics of brain revascularization using one or two EICMA. In 17 cases, ASL perfusion confirmed the targeted improvement of cerebral blood flow (CBF) in the entire hemisphere or middle cerebral artery basin. Only one EICMA was imposed in these cases. In 10 cases, a single anastomosis was insufficient for restoration of blood flow. These patients underwent additional revascularization with the second donor branch (35.7%). In all cases, we achieved significant quantitative improvement in CBF and volume of brain tissue with restored blood flow (ASPECTS scale). A single EICMA was followed by increase in CBF and areas of restored blood flow by almost 2 times (22.7±9.6 ml/100 g/min and 4.7±1.8 scores (ASPECTS) before surgery vs. 39.4±16.4 ml/100 g/min and 4.7±1.8 scores after EICMA). In the double EICMA group, these parameters increased by almost 3 times (18±3.1 ml/100 g/min and 3.8±0.9 scores before surgery vs. 57±11.4 ml/100 g/min and 7.7±1.5 scores after double EICMA). All patients had no complications. Neurological status improved immediately after surgery in 9 patients (33.3%), stable postoperative period was observed in 12 cases (44.4%). Six (22.2%) patients had transient neurological deficit associated with hyperperfusion syndrome that regressed within a few days after surgery. There were no persistent ischemic complications. CONCLUSION: Intraoperative ASL perfusion is an effective and informative tool for determining the degree of restoration of blood flow. We can timely adjust surgical strategy, determine the indications or contraindications for additional revascularization and exclude early ischemic complications using this method.

[Prognosis of overall and disease-free survival in patients with grade 3 astrocytomas (anaplastic astrocytoma, WHO 2016)]. / Faktory, opredelyayushchie prognoz obshchei i bezretsidivnoi vyzhivaemosti u patsientov s astrotsitomami grade 3 (anaplasticheskimi astrotsitomami, WHO 2016).

Anaplastic astrocytoma (AA) is a rare intracerebral tumor. Therefore, the number of studies devoted to risk factors of overall and disease-free survival is small. This single-center clinical study is devoted to various factors influencing prognosis of treatment in this group of patients. MATERIAL AND METHODS: A retrospective study included 389 patients diagnosed with grade 3 astrocytoma. We analyzed dependence of overall and disease-free survival from the following factors: gender, age of onset of disease, tumor extent, surgery, neurological disorders before and after surgery (NANO grading system), Ki67 index, postoperative radio- and chemotherapy (number courses, treatment regimens). RESULTS: Significant risk factors for overall and disease-free survival were spread and volume of tumor, postoperative neurological aggravation, Ki67 index, IDH mutation, radio- and chemotherapy. Age, frontal lobe tumor and disease manifestation variant were significant only for overall, but not for disease-free survival. CONCLUSION: This study was based on material of one of the largest clinical series of patients with AA operated on in one center in «molecular¼ era. Our results are consistent with previous data. Analysis of tumor biology and risk factors for IDH-negative AA without molecular signs of glioblastoma may be perspective.

[Variants of collateral cerebral circulation in moyamoya disease]. / Varianty kollateral'nogo krovoobrashcheniya golovnogo mozga pri bolezni moya-moya.

BACKGROUND: Moyamoya disease is a chronic progressive cerebrovascular disease with a complex pathophysiology and unique features of neoangiogenesis. These features are still known only to a few specialists, although they determine clinical course and outcomes of disease. OBJECTIVE: To determine the nature and degree of neoangiogenesis in restructuring the natural collateral circulation in patients with moyamoya disease and its effect on cerebral blood flow. The influence of collateral circulation on postoperative results and factors of its effectiveness will be analyzed in the 2nd part of the study. MATERIAL AND METHODS: The study included 65 patients with moyamoya disease who underwent preoperative selective direct angiography with separate contrast enhancement of both internal, external and vertebral arteries. We analyzed 130 hemispheres. Suzuki stage of disease, pathways of collateral circulation and their relationship with reduction of cerebral blood flow and clinical manifestations were assessed. Distal vessels of the middle cerebral artery (MCA) were additionally studied. RESULTS: Suzuki stage 3 was the most common (36 hemispheres, 38%). Leptomeningeal collaterals were the most common among intracranial collateral tracts (82 hemispheres, 66.1%). Extra-intracranial transdural collaterals were found in half of the cases (56 hemispheres). We observed certain changes in distal vessels of the MCA (hypoplasia of M3 branches) in 28 (20.9%) hemispheres. Suzuki stage of disease significantly determined degree of cerebral blood flow insufficiency, i.e. more severe perfusion deficit was observed at the later stages of disease. A well-developed system of leptomeningeal collaterals significantly reflected stages of compensation and subcompensation of cerebral blood flow according to perfusion data (χ2=20.394, p<0.001). CONCLUSION: Neoangiogenesis is a natural compensatory mechanism in moyamoya disease designed to maintain brain perfusion under reduced cerebral blood flow. Predominant intra-intracranial collaterals are associated with ischemic and hemorrhagic events. Timely restructuring on extra-intracranial ways of collateral circulation prevents adverse manifestations of disease. Assessment and understanding of collateral circulation in patients with moyamoya disease create the prerequisites for substantiating the method of surgical treatment.

[Factors of effective neovascularization after surgical treatment of moyamoya disease]. / Faktory effektivnosti neovaskulyarizatsii posle khirurgicheskogo lecheniya bolezni moya-moya.

BACKGROUND: Moyamoya disease is a chronic cerebrovascular disease with complex pathophysiology. This disease is characterized by unique and unclear features of neoangiogenesis in natural course of disease and after surgical treatment. Natural collateral circulation was discussed in the first part of the article. OBJECTIVE: To analyze the nature and degree of neoangiogenesis after combined revascularization in patients with moyamoya disease and to identify the factors of effective direct and indirect components. MATERIAL AND METHODS: We analyzed 80 patients with moyamoya disease who underwent 134 surgical interventions. The main group consisted of patients after combined revascularization (79 operations), two control groups comprised patients after indirect (19) and direct (36) operations. We assessed postoperative MR data, function of each component of revascularization considering angiographic and perfusion modes and their contribution to the overall result of revascularization. RESULTS: Factors of effective direct components of revascularization are large diameter of acceptor (p=0.028) and donor (p<0.0001) arteries, as well as double anastomoses (p=0.009). Factors of effective indirect synangiosis are younger age of patients (p=0.009), «ivy¼ symptom (p=0.005), enlargement of M4 branches of the MCA (p=0.026), transdural (p=0.004) and leptomeningeal (p=0.001) collaterals, use of more indirect components (p=0.027). Combined surgery provides the best angiographic (p=0.023) and perfusion (p<0.0001) results of revascularization. If one of the components is ineffective, other one ensures favorable result of surgery. CONCLUSION: Combined revascularization is preferable in patients with moyamoya disease. However, a differentiated approach involving the effectiveness of various components of revascularization should be taken into account when planning surgical tactics. Understanding the state of collateral circulation in patients with moyamoya disease both in natural course of disease and after surgical treatment opens the ways for their rational use.

Long-Term Results of the First Clinical Application of Stereotactic Radioablation Using a Linear Electron Accelerator for the Treatment of Ventricular Tachycardia.

We present the first clinical application of non-invasive stereotaxic radioablation of ventricular tachycardia (VT) refractory to medical and surgical treatment. Based on the results of invasive navigational activation mapping, a pericicatrical zone in the interventricular septum associated with VT was verified. Radiosurgical irradiation of the target in the region of the interventricular septum and the posterior apical segment of the left ventricle was performed on a TrueBeam linear electron accelerator (Varian) in accordance with the segmental scheme of the left ventricle. Irradiation doses for 95% of the internal target volume (ITV, 17 cm3) and planned target volume (PTV, 46 cm3) (31.2 and 25 Gy, respectively) were delivered by two full coplanar arches in 1 session. Irradiation was performed during expiration using a respiratory control system. The loading dose to critical structures was within tolerance. The planned follow-up period is 6 months. According to remote monitoring, the intensity of VT paroxysms over 48 days after treatment was from daily to 2-3 per day. Then, the incidence of VT paroxysms decreased (1-3 per week), and from the 64th to the 185th day (the end of the observation period), no VT paroxysms were recorded, which suggests that the impact was highly precise, conformal, and involved the total wall thickness. No undesirable effects and damage to adjacent organs were observed.

[Expression of estrogen and progesterone receptors in vestibular schwannomas]. / Analiz ekspressii retseptorov estrogena i progesterona v vestibulyarnykh shvannomakh.

INTRODUCTION: Stereotactic radiosurgery is one of the main treatments for vestibular schwannomas (VS). Their feature is frequent post-radiation pseudoprogression. This may be due to hormonal status of patients. OBJECTIVE: To analyze expression of progesterone and estrogen receptors in women and men with VS. MATERIAL AND METHODS: Immunohistochemical analysis of expression of progesterone (PR) and estrogen receptors (ER) after biopsy was performed in 240 patients with VS between 2018 and 2021. ER/PR expression was assessed in men (n=120) and women (n=120) in 3 age subgroups: young age (18-44 years), middle age (45-59 years) and old age (60-79 years). Each subgroup included 40 patients. Statistical analysis was performed using the Mann-Whitney test and MedCalc software. RESULTS: ER expression is not typical for VS (men - 1 (0.01%), women - 3 (2.5%)). At the same time, PR expression was found in 29 (24.2%) men and 21 (17.5%) women. We found no significant difference in expression of ER and PR between men and women. However, variability in PR expression was revealed, i.e. predominance of this indicator in young women (p=0.0463) and middle-aged men (p=0.0110). Expression of PR was similar in elderly patients (p=0.2382). CONCLUSION: The established incidence of PR expression may be one of the probable causes affecting development and duration of VS pseudoprogression after radiosurgery without clear relationship between sex and age. Further prospective research is needed to predict the risks of pseudoprogression.

[Artificial intelligence guided predicting the length of hospital-stay in a neurosurgical hospital based on the text data of electronic medical records]. / Prognozirovanie dlitel'nosti gospitalizatsii v neirokhirurgicheskoi klinike po tekstovym dannym elektronnoi meditsinskoi dokumentatsii s pomoshch'yu tekhnologii iskusstvennogo intellekta.

BACKGROUND: Rational use of internal resources of hospitals including bed fund turnover is important objective in high-tech medicine. Machine learning technologies can improve neurosurgical care and contribute to patient-oriented approach. OBJECTIVE: To evaluate the quality of AI-guided predicting the length of hospital-stay in a neurosurgical hospital based on the text data of electronic medical records in comparison with expectations of patients and physicians. MATERIAL AND METHODS: AI-guided prediction was based on analysis of unstructured text records of the electronic medical history (preoperative examination and surgical protocol). Predictive models were learned on the data of the Burdenko Neurosurgery Center accumulated for the period 2000-2017 (90.688 cases). Model testing was performed on 111 completed neurosurgical cases in a prospective study. We compared the accuracy of prediction models compared to expectations of patients and physicians regarding hospital-stay. RESULTS: The median absolute error of machine prediction in the final test was 2.00 days. This value was comparable with the doctor's prediction error. CONCLUSION: This study demonstrated the possibility of using unstructured textual data to predict the length of hospital-stay in a neurosurgical hospital.

[Role of TERT mutation for treatment prognosis in patients with IDH-negative anaplastic astrocytoma]. / Znachenie TERT-mutatsii v opredelenii prognoza lecheniya patsientov s IDH-negativnymi anaplasticheskimi astrotsitomami.

OBJECTIVE: To study the effect of TERT mutation on overall and relapse-free survival in patients with IDH-negative diffuse astrocytomas grade III (anaplastic gliomas). MATERIAL AND METHODS: The study included 45 patients aged 45.5 years. Forty-two patients underwent resection of tumor, other 3 ones - stereotactic biopsy. TERT mutation was identified in 21 patients. External beam radiation therapy was performed in 35 patients (60 Gy), chemotherapy - in 34 patients (mainly temozolomide). Follow-up data were available in 44 patients. RESULTS: Median of overall survival in patients with TERT mutation was 15.3 months, in patients with TERT-negative tumors - 65.1 months. Median of relapse-free survival in patients with TERT-positive anaplastic astrocytoma (AA) was 13.3 months, in patients with TERT-negative glioma - 57.7 months. These differences were not significant. Relapse-free survival was higher in patients with AA and no TERT mutation at all intervals, but especially at early stages (12 and 24 months). CONCLUSION: Inclusion of TERT mutation in mandatory examination panel for gliomas in general and, in particular, gliomas grade II/III without IDH mutation can lead to sub-classification of these tumors in the near future. Routine analysis of TERT mutation in these patients will be valuable for correct medical consultation regarding prognosis and adequate adjuvant treatment.

[Anaplastic pleomorphic xanthoastrocytoma - single-center analysis of 42 patients]. / Anaplasticheskaya pleomorfnaya ksantoastrotsitoma ­ analiz 42 nablyudenii iz odnoi kliniki.

Anaplastic pleomorphic xanthoastrocytoma is a rare tumor. There are still no objective data on the incidence of its diagnosis. OBJECTIVE: To study neuroimaging, morphological features of tumors, as well as factors affecting treatment and prognosis. MATERIAL AND METHODS: A retrospective study enrolled 42 patients operated on at the Burdenko Neurosurgery Center between 2003 and 2020. MR characteristics of anaplastic pleomorphic xanthoastrocytoma were analyzed. All patients underwent resection of tumor (total resection in 83.3% of cases). Redo surgeries were performed in 1/3 of patients. Mutational status of BRAF V600E was assessed in all patients. Adjuvant radio- and chemotherapy was performed in more than 80% of cases. Tyrosine kinase inhibitors were administered in 19% of cases. The follow-up period was 152 months (median 34 months). RESULTS: We found no pathognomonic MR signs of this disease. Indeed, anaplastic pleomorphic xanthoastrocytoma have the same signal characteristics as other malignant gliomas. The BRAF V600E mutation status was positive in 54.8% of cases. None patient had IDH-1 mutation. Mean Ki-67 index was 12.5%. The overall survival was 79 months (range 4-152). Seven (17%) patients are alive for more than 90 months. Only Ki-67 index and BRAF mutation significantly influenced the treatment prognosis and overall survival regardless the use of tyrosine kinase inhibitors. CONCLUSION: Such well-known factors for malignant glioma as patient age, total resection and adjuvant therapy did not significantly affect overall survival. Perhaps, searching for new molecular genetic features will reveal additional significant factors of prognosis in patients with anaplastic pleomorphic xanthoastrocytoma.

[Stereotactic radiosurgery for vestibular schwannoma: early and long-term radiation-induced changes and tumor growth control]. / Radiokhirurgiya vestibulyarnykh shvannom: dinamika blizhaishikh i otdalennykh postluchevykh izmenenii i kontrol' opukholevogo rosta.

Stereotactic radiosurgery of vestibular schwannoma is an effective and safe method of treatment. The phenomenon of schwannoma pseudo-progression (transient post-radiation enlargement) complicates assessment of the outcomes after radiosurgery. OBJECTIVE: To investigate the changes of vestibular schwannoma in different periods after radiosurgery. MATERIAL AND METHODS: We analyzed early and long-term radiation-induced changes in 333 patients who received Gamma Knife treatment at the Burdenko Neurosurgery Center between April 2005 and December 2015. Mean follow-up period was 60 months (range 15-167). There were 89 men (26.7%) and 244 (73.4%) women. Mean age of patients was 48.2 years. Mean baseline tumor volume was 4.1 cm3 (range 0.1-14.5). Dynamics of changes was assessed using volumetric comparison. RESULTS: Tumor shrinkage without pseudo-progression was observed in 149 (44.7%) patients. Typical pseudo-progression in different variants was found in 131 (39.3%) patients, i.e. short-term (1 year) and long-term (≥2 years) course, complete and incomplete process. Eleven patients had atypical pseudo-progression after initial tumor shrinkage. Progression-free 5- and 10-year survival in the entire group was 87 and 81%, respectively. Progression-free 5-year survival rate was 95 and 92% in patients with and without pseudo-progression, respectively. Ten-year survival rate was 89 and 89%, respectively. CONCLUSION: Knowledge of pseudo-progression features is essential for the most reasonable and reliable assessment of treatment results and justification of timing and frequency of subsequent MR control. Atypical course of pseudo-progression can simulate tumor recurrence. In case of tumor enlargement at any follow-up stage after radiosurgery, advisability of surgery should be determined considering clinical data and likelihood of tumor shrinkage following natural regression of post-radiation tumor enlargement.

[Neurosurgeon training: current problems and modern approaches]. / Obuchenie neirokhirurga: aktual'nye problemy i sovremennye podkhody.

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.

[Ischemic complications following surgical treatment of moyamoya disease: risk factors and prevention]. / Ishemicheskie oslozhneniya khirurgicheskogo lecheniya patsientov s bolezn'yu moiya-moiya: faktory riska i metody profilaktiki.

BACKGROUND: One of the most difficult problems in surgical treatment of moyamoya disease is prevention of ischemic perioperative complications. The risk of these events is significantly higher compared to other cerebrovascular diseases (up to 30%). OBJECTIVE: To identify unfavorable prognostic factors of perioperative cerebral ischemic complications, to determine the group of high-risk patients and to develop the guidelines for perioperative management of these patients. MATERIAL AND METHODS: We analyzed clinical and diagnostic data and postoperative outcomes in 80 patients with various forms of moyamoya disease. These patients underwent 134 different interventions. Staged revascularization of both hemispheres was performed in 40 patients (80 surgeries). Most patients (n = 55) underwent combined brain revascularization (79 surgeries). RESULTS: Persistent postoperative complications (ischemic stroke) developed in 7 cases (5.3%). Transient neurological impairment was observed in 36 cases (27%). Statistical analysis revealed the following risk factors of perioperative complications: critical stenosis/occlusion of posterior cerebral artery (OR 9.704), severe perfusion deficit (OR 5.393) and previous TIA or ischemic stroke within 3 months prior to surgery (OR 6.433). If at least two of these signs are present, sensitivity of prognosis for postoperative complications is 80.7% and 88.6%, respectively. CONCLUSION: Patients with moyamoya disease are at high risk of perioperative complications due to complex rearrangement of collateral cerebral circulation and high sensitivity of brain to local and systemic hemodynamic changes. Patients with risk factors require careful perioperative management to exclude pathogenetic factors provoking ischemia. Early surgical treatment is advisable to reduce the risk of ischemic and hemorrhagic lesions following natural course of disease and severe perioperative complications.

[Risk factors of nosocomial meningitis in neurological intensive care unit. Results of a five-year prospective study]. / Faktory riska razvitiya nozokomial'nykh meningitov u patsientov neirokhirurgicheskogo profilya v otdelenii reanimatsii i intensivnoi terapii. Rezul'taty pyatiletnego prospektivnogo issledovaniya.

Nosocomial meningitis (NM) is a serious complication in neurosurgery. Understanding the risk factors of nosocomial meningitis is important for their prevention. OBJECTIVE: To determine the main risk factors of NM in neurological intensive care unit. MATERIAL AND METHODS: A prospective study included all patients (n=2140) treated at the neurological intensive care unit for more than 48 hours between October 1, 2010 and October 31, 2015. Cases of nosocomial meningitis were registered. We analyzed risk factors in 2 groups of patients (with and without NM). RESULTS AND DISCUSSION: The incidence of NM in neurological intensive care unit was 8.4% (95% CI 6.8-10.0) (n=180). Relative risk of NM under external ventricular drainage was 3.98 (99 cases of NM, p<0.05). Relative risk of NM in patients with CSF leakage (including nasal CSF leakage after transsphenoidal surgery) was 5.2 (49 cases of NM, p<0.05). The incidence of nosocomial meningitis was significantly higher among patients with surgery time ≥8 hours (17.68%, p<0.01). Nosocomial meningitis was also significantly more common after redo surgery (13.07%, p<0.05). Insertion of intracranial pressure sensor was not a significant risk factor of NM. The risk of meningitis was 2.67% if the above-mentioned factors were absent. Extracranial factors are not specific for NM. No significant relationship between certain neurosurgical disease and NM was found. CONCLUSION: We found higher risk of NM in ICU patients with the following factors: external ventricular drainage, CSF leakage, redo surgery and surgery time.

[Changes in treatment paradigm for neurosurgical patients in the era of stereotactic irradiation. By the 15th anniversary of the Neuroradiosurgery in Russia]. / Izmenenie paradigmy lecheniya neirokhirurgicheskikh patsientov v epokhu stereotaksicheskogo oblucheniya. K 15-letiyu neiroradiokhirurgii v Rossii.

INTRODUCTION: Stereotactic method and new irradiation techniques ensured radiosurgical treatment with high precision and conformity and significantly expanded the indications for stereotactic irradiation in neurosurgery. MATERIAL AND METHODS: Over 15-year period, 29 976 patients underwent irradiation in various modes of fractionation on linear accelerators and Gamma Knife system at the first national radiosurgery center. RESULTS: Stereotactic radiotherapy and radiosurgery are followed by minimal number of complications and side reactions. At the same time, 5-year control of tumor growth for skull base meningioma was 96.8%, neuroma - 97%, glomus tumor - 94%, pituitary adenoma - 96-98%, craniopharyngioma - 95% in overall 10-year survival 86%, pilocytic astrocytoma - 97.5% in overall 5-year survival 99%. In intracranial metastases, median overall survival after radiosurgery was 10.1 months, 24- and 36-month overall survival - 25.9% and 19.2%, respectively. In patients with recurrent high-grade glioma, overall survival was 27.4 months. In case of metastatic spine lesions, control of tumor growth within 1 year was achieved in 90% of patients, pain relief - in more than 50% of cases. Obliteration of AVM and dural fistula was found in more than 80% of patients in years after treatment. Reduction or disappearance of pain was also observed in 80% of patients with trigeminal neuralgia. CONCLUSION: Stereotactic irradiation is effective and safe in patients with various pathologies of the central nervous system and characterized by high socio-economic indicators. Our own data indicate more significant role of stereotactic irradiation in the treatment of neurosurgical patients and make it possible to revise the existing treatment standards.

[Anaplastic astrocytoma and anaplastic oligodendroglioma of the brain: current state of the problem]. / Anaplasticheskie astrotsitomy i anaplasticheskie oligodendrogliomy golovnogo mozga: sovremennoe sostoyanie problemy.

This review is devoted to the problem of anaplastic cerebral gliomas. The authors consider classification, neuroimaging of these tumors including comparison of magnetic resonance imaging and positron emission tomography data. Clinical manifestations of anaplastic gliomas, issues of their histological and molecular genetic classification are discussed. Moreover, the authors compare the data of neuroimaging and genetic examinations of tumors. Other issues are multicomponent treatment and prognosis in patients with anaplastic glioma of the brain.