[Surgical treatment of brain tumors adjacent to corticospinal tract in children]. / Aktual'nye voprosy khirurgicheskogo lecheniya opukholei golovnogo mozga, prilegayushchikh k kortikospinal'nomu traktu u detei.

An urgent problem in modern neurosurgery is resection of brain tumors adjacent to corticospinal tract (CST) due to high risk of its damage and subsequent disability. The main methods for prevention of intraoperative damage to CST are preoperative MR tractography and intraoperative electrophysiological monitoring. Both methods are used in pediatric neurosurgery. We reviewed the PubMed database since 2000 using the following keywords: «tumors of the hemispheres in children¼, «corticospinal tract¼, «MR tractography¼, «intraoperative electrophysiological monitoring¼. We present available literature data on preoperative MR tractography and intraoperative electrophysiological monitoring in children with supratentorial tumors near CST. Algorithm of intraoperative electrophysiological monitoring is often missing or insufficiently described. MR tractography is usually presented in case reports. Researchers do not compare the effectiveness of MR tractography and intraoperative electrophysiological monitoring. In case of MR tractography, a limitation is impossible CST reconstruction in children 2-3 years old. This may be due to unformed pyramidal system in these children. CONCLUSION: Preoperative MR tractography and intraoperative electrophysiological monitoring are valid methods for assessment of CST. Optimal research parameters in children require careful study that will allow objective planning of each stage of preoperative management and increase resection quality for gliomas near CST in children without neurological deterioration.

[Astrocytoma with 1p19q codeletion]. / Astrotsitoma s kodeletsiei 1p19q.

Using the example of a recurrent tumor with a 10-year follow-up, the authors show that mutation of the IDH1/2 genes in astrocytomas is not always an early event in the pathogenesis of glioma, that in rare cases a 1p19q codeletion can be found in astrocytomas, and that IDH-mutant tumors can occur in childhood.

[Surgical treatment of hemispheric and subcortical gliomas adjacent to corticospinal tract in children using MR tractography and intraoperative electrophysiological monitoring]. / Opyt khirurgicheskogo lecheniya gliom bol'shikh polusharii i podkorkovykh struktur golovnogo mozga, prilegayushchikh k kortikospinal'nomu traktu, u detei s ispol'zovaniem MR-traktografii i intraoperatsionnogo elektrofiziologicheskogo monitoringa.

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.

[Surgical treatment of giant tumors of the cerebral hemispheres in children]. / Khirurgicheskoe lechenie gigantskikh opukholei bol'shikh polusharii golovnogo mozga u detei.

The article provides a literature review of the principles and the results of surgical treatment of giant tumors of the cerebral hemispheres in children. The article highlights the unsolved problems of modern neurosurgery of giant tumors.

[Embryonal tumor with multilayered rosettes (ETMR): case report and literature review]. / Embrional'naya opukhol' s mnogosloinymi rozetkami (embryonal tumor with multilayered rosettes ­ ETMR): sluchai iz praktiki i obzor literatury.

Embryonal tumor with multilayered rosettes (ETMR) is a rare and highly malignant brain tumor that develops in children younger 4 years old. This neoplasm is characterized by extremely aggressive course, low sensitivity to chemotherapy and radiotherapy. Thanks to the progress of pathologists, diagnosis of ETMR is now available using immunohistochemical examination with LIN28A and SALL4 antibodies. Moreover, detection of microRNA amplification in the 19q13.42 locus by fluorescent hybridization in situ allows an unmistakable diagnosis.The authors describe clinical course and treatment outcome in a 2-year-old patient with a giant tumor of the right parietotemporal region. Postoperative histological examination verified ETMR. Despite adjuvant treatment, we observed fast progression of disease and unfavorable outcome after 5 months. Case report is supplemented by literature review. CONCLUSION: ETMR is very rare and poorly understood neoplasm. The authors present a giant hemispheric ETMR in a 2-year-old boy with an extremely aggressive course of disease. Despite the advances in diagnosis and treatment of CNS tumors in children, there are currently more questions than answers regarding ETMR. Pooled analysis of all available data with large-scale studies is needed. It is necessary to emphasize an exceptional role of each clinical case for global study of this tumor. Timely adjuvant/neoadjuvant therapy in highly specialized centers is also essential.

[Sarcomas of the central nervous systems. Clinical observations]. / Sarkomy tsentral'noi nervnoi sistemy. Klinicheskie nablyudeniya.

Here we report three patients with rare primary intracranial sarcomas, two of them were CIC-sarcomas and one was a DICER1-sarcoma. Tumors were examined using DNA methylation. It is important to study of CIC fusions and DICER1 mutations in malignant brain tumors.

[Influence of resection quality on postoperative outcomes in children with atypical teratoid-rhabdoid tumor of the central nervous system]. / Vliyanie radikal'nosti operativnogo vmeshatel'stva na rezul'taty lecheniya atipichnoi teratoidno-rabdoidnoi opukholi tsentral'noi nervnoi sistemy u detei.

The purpose of this study was to assess the influence of resection quality on overall survival and disease-free survival in children with atypical teratoid-rhabdoid tumors (ATRT). The study included children younger than 18 years old for the period from 2008 to 2019. There were 134 interventions in 105 patients with ATRT including 11 redo resections («second-look¼ surgery) and 18 procedures for tumor recurrence. Age of patients ranged from 2 to 168 months (median 21 months). Patients with supratentorial tumors prevailed (50.5%), infratentorial neoplasms were diagnosed in 45.7% of patients, spinal cord lesion - 3.8% of cases. At the first stage, all patients underwent surgical treatment. Total resection was achieved in 34 (32.4%) patients, subtotal - 37 (35.2%) patients, partial resection - 30 (28.6%) patients. Biopsy was performed in 4 (3.8%) patients. Quality of resection and age at surgery significantly influenced overall and disease-free survival. Extended resection of tumor followed by adjuvant chemo- and radiotherapy are required to improve survival although ATRTs are high-grade neoplasms with poor prognosis.

[Stereotactic irradiation in the complex treatment of patients with intracranial pilocytic astrocytoma]. / Stereotaksicheskoe obluchenie v kompleksnom lechenii patsientov s intrakranial'nymi piloidnymi astrotsitomami.

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.

[Central nervous system atypical teratoid/rhabdoid tumor without loss of nuclear expression of INI1]. / Atipicheskaia teratoidno-rabdoidnaia opukhol' TsNS bez poteri iadernoi ékspressii INI1.

The paper describes a clinical case of atypical teratoid/rhabdoid tumor with preserved INI1 expression and SMARCA4 gene mutations in an 8-month-old girl. Genome-wide DNA methylation, hierarchical clustering, and next-generation sequencing were used to make a tumor diagnosis. However, BRG1 immunohistochemical examination may be recommended in the routine practice of diagnosis and study of childhood CNS malignant tumors.

[Chronic sacral nerve electrostimulation in treatment of neurogenic pelvic organ dysfunction in children]. / Khronicheskaia sakral'naia élektrostimuliatsiia v lechenii neirogennoi disfunktsii tazovykh organov u detei.

Myelodysplasia is the most common cause of congenital pelvic abnormalities in children. The causes of acquired neurogenic pelvic dysfunctions in children include spinal cord injury, myelitis, and neurodegenerative diseases. Urination impairments in children with neurological disorders are a serious clinical problem. In most cases, the capabilities of conservative treatment of pelvic organ dysfunctions are limited. One of the most promising directions in treatment of neurogenic urination disorders is modeling of a lost urination mechanism using direct or mediated electrostimulation of the nerve fibers of the sacral plexus - neuromodulation. AIM: the review aim is to describe the technique and results of chronic sacral neurostimulation in treatment of pelvic organ disorders in children, which have been reported in the international literature. An obligatory condition for application of chronic sacral neurostimulation (CSNS) is a positive clinical response to test electrostimulation of the S3 nerve root. The test period duration is 1-3 weeks. In the case of a positive effect, a permanent system is implanted for neurostimulation of the S3 nerve root. On treatment with CSNS, children with severe urinary incontinence had a significant decrease in the rate of incontinence episodes, and patients with urinary retention had no or reduced need for periodic catheterization. Therefore, the accumulated experience of using CSNS in children with spinal cord diseases indicates the need in further study of the technique capabilities for correction of pelvic organ dysfunctions.

[MR tractography in diagnosis and choice of a neurosurgical approach to basal ganglia tumors]. / MR-traktografiia v diagnostike i vybore neirokhirurgicheskogo dostupa pri opukholiakh podkorkovykh uzlov.

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.

[Posterior decompression of the craniovertebral junction in syringomyelia combined with Chiari-1 malformation in children]. / Rezul'taty zadnei dekompressii kraniovertebral'nogo perekhoda pri siringomielii s anomaliei Kiari-1 u detei.

OBJECTIVE: to develop the algorithm for defining the amount of posterior decompression of the craniovertebral junction in children with syringomyelia combined with Chiari-1 malformation. MATERIAL AND METHODS: Sixty eight children with syringomyelia and Chiari-1 malformation, under age of 18 years, underwent posterior decompression of the craniovertebral junction (PDCVJ) in the period from January 2001 to June 2016. Seven (10%) patients underwent extradural decompression (EDD), 16 (24%) patients underwent extra-arachnoid duraplasty (EAD), 25 (37%) patients underwent intra-arachnoid dissection (IAD) and duraplasty, and 20 (29%) patients underwent PDCVJ and placement of a fourth ventricle-subarachnoid shunt. RESULTS: Clinical improvement occurred in 85% of patients, and stabilization was observed in 11% of patients. Syringomyelia regressed in 78% of cases. There were no complications associated with EDD; however, re-operation was required in 3 (43%) cases. In the case of EAD, treatment results were satisfactory in 11 (79%) patients; re-operation was required in 2 (12.5%) cases; there were no complications in the early postoperative period. The highest complication rate of 6 (30%) cases was associated with shunt placement and duraplasty. However, long-term results in this group of patients were satisfactory in 16 (94%) cases, and MRI-based positive changes were observed in 100% of cases. CONCLUSION: According to our analysis, EAD is the method of choice for PDCVJ in children with syringomyelia and Chiari-1 malformation without myelopathy symptoms. In the presence of myelopathy symptoms, intra-arachnoid dissection (with or without shunting) is an acceptable alternative. To our opinion, the use of EDD in syringomyelia is unadvisable.

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

UNLABELLED: 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.

[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.

[Stereotactic radiotherapy and radiosurgery in treatment of patients with deep-seated pilocytic astrocytomas].

Pilocytic astrocytoma (PA) is a low-grade glial tumor (WHO grade I) with predominant occurrence in pediatric patients. According to many authors, stereotactic radiosurgery (SRS) and radiotherapy (SRT) promote long-term remission or retardation of tumor progression in patients with in inoperable lesions after incomplete resection or recurrence. Therefore it is essential to determine the role of SRS and SRT in complex management of patients with deep-seated PA. Since April 2005 till May 2010 101 patient with intracranial PA was treated in department for radiation therapy of Burdenko Neurosurgical Institute. The series consisted of 70 pediatric patients (below 17 years inclusively) and 31 adults, of them--51 male and 50 female patients. Mean age was 15.1 years (9.8 years in children and 28.7 in adults). In 90 patients (89.2%) tumors were previously histologically verified (tumor resection in 83 cases and biopsy in 7). In 11 (10.8%) patients diagnosis of PA was based on clinical and neurovisualization data. In most cases SRT (66 (66.3%) patients) was preformed, the rest 35 (34.7%) patients were treated by SRS. Median follow-up from the onset of disease reached 52 months (2-228 months). Catamnestic data were available in 88 (87%) patients. By the end of catamnestic follow-up (December 2010) 87 (98.8%) patients treated by SRS and SRT were alive. Median follow-up from the start of radiation treatment was 22.7 months (6-60 months). Progression of tumor was observed in 20 patients (22.7%), in 18 of them due to cyst growth. 18 patients were reoperated. In 12 operated patients histological examination and its comparative analysis were performed. We found that alterations in the tumor tissue, accompanied by regression of solid component and progression of cystic portion, represent reactive-degenerative changes in the tumor as a consequence of radiation-induced pathomorphism. SRS and STR are effective techniques for treatment of patients with primary and recurrent PA despite regardless of localization of the tumor. There procedures should be performed shortly after non-radical resection. Control of tumor growth by the present time (median follow-up is 22.7 months) reaches 98%. "Progression" of the tumor due to enlargement of cystic portion shortly after SRT and SRS represents reactive-degenerative alterations in the tumor tissue and should not be evaluated as true recurrence; without neurological deterioration these cases do not require special treatment.

[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.

[Surgical approaches to thalamic tumors].

The paper summarizes the results of surgical treatment of patients with thalamic tumors of different topographic variants. Since 1985 till 2010 127 patients were operated, 147 direct surgical interventions were performed. Repeated surgeries were required due to partial resection of a tumor or recurrence. In most cases resection of tumors was performed via transcallosal (48%) and occipital interhemispheric (29%) approaches. Less common approaches included transcortical (frontal, temporal, parietal) (14%), pterional through lateral and basal parts of Sylvian fissure (6%) and subtentorial supracerebellar (3%). Selection of approach is based on topographic features of tumor within thalamus, direction of its growth and relations with adjacent structures (internal capsule, brainstem, hypothalamus, ventricular system). Each approach has its own advantages and drawbacks which are highlighted in the paper.

[Diffuse hyperplasia of choroid plexuses of lateral ventricles].

Diffuse hyperplasia of choroid plexuses of lateral ventricles is extremely rare entity which is characterized by diffusely increased size of choroid plexuses along the entire choroid fissure and CSF hypersecretion. This disease, initially described by Davis in 1924, may be fallaciously diagnosed as bilateral choroidpapillomas. We present a case of diffuse hyperplasia of choroid plexuses of lateral ventricles in a female infant.