Background. Primary tumors of central nervous system account for about 2 % of all human tumors. Generally, the tumor removal is a necessary treatment step. The main goal of the intracerebral tumors surgical treatment is the formation removal in the most radical physiologically possible way, because this directly affects the patients’ life length and its quality.

Aim. To assess the results of surgical treatment of motor zone tumors and identify predictors of development of irreversible motor disorders.

Materials and methods. A retrospective analysis of results of surgical treatment from 105 patients with tumors that affect corticospinal tract and primary motor cortex of the brain or localized in close proximity to those areas (up to 10 mm). All patients were treated in the neurosurgical department of N.I. Pirogov National Medical and Surgical Center, Ministry of Health of Russia (Moscow) in the period from 2014 to 2020. There were 48 (46 %) men, 57 (54 %) women aged from 22 to 79 (mean age 47.6 ± 14.5) years. Tumors volume before surgery ranged from 5.16 to 283.3 (mean volume 80.9 ± 55.1) cm³. The tumors’ size and their relationship with the surrounding structures were assessed by pre‑surgery magnetic resonance imaging and magnetic resonance tractography. For the intraoperative assessment of motor zone state dynamics, the transcranial electrical stimulation (n = 105, 100 %) and direct transcortical stimulation (with the eight‑contact electrode stripe) (n = 68, 64.8 %) of the primary motor cortex were used. To assess the proximity of the motor zones, a straight cortical and subcortical bi‑ or monopolar electrical stimulation was used (n = 105, 100 %).

Results. Sixty‑seven tumors (63.8 %) were removed completely, close to total removal was in 22 (20.9 %) tumors, 11 (10.5 %) tumors removal was subtotal and 5 (4.8 %) tumors were removed partially. Tumor volume after surgery ranged from 0 to 84.4 (mean volume – 3.54 ± 5.01) cm³, Development of novel motor deficiency or increase in pre‑surgery motor deficiency was observed in 46 (43.8 %) patients 24 hours after surgery and in 32 (30.5 %) of them 7 days after the treatment. However, during course of conservative therapy, the majority of patients showed regress of motor deficit and it remained only in 12 (11.4 %) patients on examination that was performed 6 months after surgery. Assessment of factors affecting development of persistent motor deficiency revealed its statistically significant association with intraoperative response decrease according to transcranial stimulation (p < 0.001) and transcortical stimulation (p < 0.001) data. There were no significant changes in the functional status of patients during postoperative period depending on strength of the direct stimulation when the resection was stopped (р = 0.9) or depending on radicality of tumor removal (p = 0.393).

Conclusion.

1. Removal of tumors of motor cortex and corticospinal tract using the multimodal neurophysiological mapping allows to achieve maximal resection of the tumor tissue with good functional outcomes. All of the above leads to significant improvement of patients’ life quality and allows further chemoradiotherapy.
2. Combined use of 4 methods of the neurophysiological mapping (transcranial, transcortical, direct cortical ang sub‑cortical stimulation) helps to minim ize the disadvantages of each of the methods and achieve radicality of the motor zone tumor removal with maintai ning their functional status.
3. Motor deficiency in patients increases after removal of motor zone tumors and then gradually restores to the original level or is improved 6 months after surgery.
4. A predictor of development of persistent motor deficiency is decrease in amplitude of motor evoked potentials by 50 % or more from baseline (according to transcranial and transcortical neurophysiological stimulation data).
5. When the motor evoked potentials in response to 1 mA direct monopolar neurostimulation are preserved then resection of the tumor is not a predictor of irreversible motor disorders during postoperative period.

Background. Prevention of ischemic stroke in patients with carotid artery occlusion is conventionally associated with performing cerebral revascularization. However, determining the indications for it is still an actual problem. The informative value of noninvasive assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries in patients with carotid artery stenosis is shown. At the same time, in patients with carotid artery occlusion, these indicators have been studied to a lesser extent.

Aim. To evaluate the informative value of cerebral autoregulation and blood flow distribution in the precerebral arte ries for determination the indications of extra‑intracranial bypass in patients with carotid occlusion.

Materials and methods. 54 patients (aged from 41 to 83 y. o.) with carotid artery occlusion were studied. Blood flow velocity in intracranial arteries was determined with transcranial Doppler (system Multi‑Dop X), whereas flow velocity index in precerebral arteries – with duplex scanning (system Vivid Е). Cerebral autoregulation was assessed based on phase shift between spontaneous oscillations of blood flow velocity in basal cerebral arteries and systemic blood pressure within the range of Mayer’s waves (80–120 mHz).

Results. The state of cerebral autoregulation was imparied on both sides in 90 % patients with the symptomatic carotid occlusion (0.3 ± 0.3 rad ipsilateral, 0.7 ± 0.6 rad contralateral). The state of cerebral autoregulation was not impaired in 79 % patients with asymptomatic carotid occlusion (1.0 ± 0.3 rad ipsilateral, 1.1 ± 0.4 rad contralateral). The flow velocity index in the contralateral internal carotid artery (306 ± 109 ml / min) and the ipsilateral vertebral (139 ± 69 ml / min) and external carotid (175 ± 72 ml / min) arteries was increased.

Conclusions. Noninvasive preoperative assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries makes to evaluate the state of the cerebrovascular reserve to quantify and can be used to determining indications for cerebral revascularization in patients with carotid occlusion.

Background. The incidence of craniopharyngiomas is up to 15 % of intracranial tumors in children. The endoscopic endonasal approach (EEA) is widely spread nowadays and especially for the craniopharyngiomas removal in adults. Nevertheless, this approach is still not so common in pediatric patients. The endoscopic technique significantly improves the visualization of the structures located around the tumor.

Aim. To determine the possibilities and limitations for the use of EEA in the treatment of pediatric patients with cranio pharyngiomas.

Materials and methods. A total five pediatric patients with craniopharyngiomas were operated via EEA Federal Center of Neurosurgery of Ministry of Health of Russia (Novosibirsk): the age of patients ranged from 4 to 17 years, including 3 boys and 2 girls. All patients at the preoperative stage already had endocrine disorders in one volume or another. Postoperative evaluation of the visual functions showed the improvement in one patient, three patients remained unchanged and one patient developed worthening. In addition, the volume of the sphenoid sinus was studied, the degree of pneumatization of which determines the anatomical accessibility of the tumor.

Results. Our experience of the EEA for the craniopharyngiomas in pediatric patients has shown a positive result regarding to the tumor’s gross‑total removal and no data of the tumor recurrence at the follow‑up. According to our results it can be judged that endonasal endoscopic approach for the craniopharyngiomas in pediatric patients could be a method of choice based on the anatomical accessibility of the tumor and its relationships with the critical neurovascular structures.

Conclusions. Endoscopic endonasal removal of craniopharyngiomas in pediatric patients can be successfully used when the tumor is anatomically accessible. The experience of using EED in surgery for craniopharyngiomas in children has shown positive results, including a high radical removal of the tumor and the absence of relapses during further follow‑up of patients.

Background. Acromegaly is a rare disease associated with insulin‑like growth factor 1 hyperproduction due to the presence of pituitary adenoma in the patient. The first‑line treatment of such patients is surgical removal of the formation in order to normalize hormonal status. The main predictors of the ineffectiveness of surgical treatment and relapse of the disease are large tumor size, tumor invasion into the cavernous sinus, and high preoperative levels of growth hormone, as well as Ki‑6 % expression. The search for additional risk factors for disease recurrence, which according to various sources is approximately 30 % after primary surgical treatment, is an urgent task for researchers. In our work, we studied the intraoperative characteristics of the tumor, size of pituitary adenomas according to preoperative magnetic resonance imaging of the brain, degree of invasion of the tumor into the cavernous sinus according to the Knosp classification and compared them with disease outcomes after a year of follow‑up after surgical treatment.

Aim. To identify new markers of aggressive progression of pituitary tumors.

Materials and methods. A retrospective analysis of medical documentation, protocols of operations of 90 patients aged between 19 and 73 years with the diagnosis of growth hormone‑secreting pituitary adenoma was performed. The dia gnosis was confirmed based on clinical picture, laboratory and instrumental examination methods. All patients underwent endoscopic transsphenoidal removal of pituitary adenoma by one surgeon in one medical institution between 2017 and 2019.

Results. Intraoperative characteristics of the tumor, such as the color of the solid component, density, degree of vascularization were compared with the results of laboratory and instrumental data, as well as the results of surgical treatment after a year of follow‑up.

Conclusion. Such intraoperative characteristics of growth hormone‑secreting pituitary adenomas as the purplish‑gray color of the solid component, high vascularization, as well as dense‑elastic consistency of the tumor, can be considered high risk factors for continued tumor growth in the first 6 months after surgical treatment or relapse of the disease during a year of follow‑up.

Background. Lumbar spinal stenosis is a pathological constriction of the central spinal canal, lateral pocket or intervertebral foramen. The complication rate of lumbar spinal stenosis surgery ranges from 10 to 24 %. In order to reduce the number of intraoperative and early postoperative complications accompanied by the development of neurological deficit, various techniques of intraoperative neurophysiological monitoring are used.

Aim. Study of informativity of the use of intraoperative neurophysiological monitoring during surgical treatment of degenerative lumbar spinal stenosis based on the experience of the neurosurgical department of the Republican Clinical Hospital (Yoshkar‑Ola, Mari El Republic).

Materials and methods. Thus, 69 decompressive‑stabilizing surgical interventions for degenerative lumbar spinal stenosis at the L3–L5 level, performed with intraoperative neurophysiological monitoring (free‑run electromyography, transcranial motor evoked potentials, somatosensory evoked potentials, triggered electromyography were included in the retrospective study).

Results. During intraoperative neurophysiological monitoring transcranial motor evoked potentials from the legs was registered in all cases. Normal somatosensory evoked potentials were recorded in most cases, in 12 cases (17.4 %) baseline somatosensory evoked potentials were not registered due to preoperative neurological deficits and the presence of concomitant somatic pathology. 308 inserted pedicular screws were examined using the triggered electromyography. Muscle responses were registered in 31 (45 %) operations, 45 (14 %) screws. True negatives were registered with 29 (64.4 %), true positives were registered with 12 (26.7 %), and false positives were registered with 4 (8.9 %) screws. In the postoperative period no increase in motor and sensory neurological deficits was observed in all patients; no neurological signs of screw malpositioning were revealed.

Conclusion. The use of multimodal intraoperative neurophysiological monitoring during surgical treatment of lumbar spinal stenosis reduces the risk of postoperative neurological complications.

Introduction. Craniotomy in conscious patients is a possible tool for optimizing of tumor resection degree (Extent of Resection) while maintaining the quality of life. Traditionally, the main focus during these operations is on the cortical speech areas. At the same time, there is a shortage of studies on mapping of long associative tracts during the removal of gliomas of dominant speech hemisphere.

Aim. To analyze the data of intraoperative mapping and the postoperative state of speech function in patients with temporal lobe gliomas of left hemisphere (including those involving arcuate bundle) operated by the use of method of craniotomy in consciousness.

Materials and methods. Gliomas of temporal lobe of left hemisphere were removed in 27 patients aged 14 to 67 years (median age 43 years). In 10 patients, the tumor was localized in middle parts of temporal lobe (at the level of middle and upper temporal gyri), in 9 patients – in posterior parts of temporal lobe and exited into the supramarginal zone, in 8 it spread partially from temporal lobe to insular area. Gliomas of high degree of malignancy were detected in 21 patients, 6 had tumors of low degree of malignancy. Surgical intervention was performed with intraoperative “awakening”. All patients underwent cortical electrophysiological stimulation in order to control localization of cortical speech zones, subcortical stimulation was performed in 21 cases to identify terminals of arcuate bundle. Speech disorders before and after surgery (on day 4–6) were evaluated by neuropsychologist using the method proposed by A. R. Luria, an automated test with the naming of pictures was additionally used intraoperatively. The average current strength of direct electrical stimulation was 3 (1.9–6.5) mA. In 12 cases, magnetic resonance (MR) tractography with construction of arcuate tract was performed before and after the surgery.

Results. Cortical temporal speech zones during intraoperative electrical stimulation were detected in 20 (74 %) of 27 patients. In 10 patients, the arcuate tract was mapped in form of appearance of mixed speech disorders in the depth of surgical wound. In 23 (85.2 %) of 27 patients in early postoperative period, an increase in speech disorders was noted of which 13 people had disorders of temporal type only and 10 people (surgery on deep posterior parts of temporal lobe) had a combination of temporal and frontal types of speech disorders (conduction aphasia). Postoperative MR‑tractography (performed in 12 patients) revealed direct intraoperative tract lesion in 5 cases and ischemia of the tract area passage in 2 cases. These 7 patients had combined speech disorders after surgery. Gross sensory aphasia after surgery was manifested in 4 patients, in 2 of them ischemia was revealed according to postoperative magnetic resonance imaging, and 2 more had hemorrhagic impregnation in the removed tumor bed.

Conclusion. When removing tumors of temporal lobe in “awakening” conditions it is necessary to map speech zones not only in the cortical, but also in the subcortical area with terminals of arcuate bundle. Mapping of speech zones in these different localizations makes it possible to identify fundamentally different speech disorders.

Background. Periventricular heterotopia is one of the causes of the intractable epilepsy. Different treatments of this pathology show variable efficacy.

Aim. To present the result of radiofrequency ablation of periventricular heterotopia in a patient with drug‑resistant epilepsy.

Materials and methods. 33‑year‑old female patient has been suffering from epilepsy since the age of 19 with frequent focal seizures (up to 70–80 times a month) and bilateral tonic‑clonic seizures (up to 4–6 times a year). In 2018 the patient underwent resection of the right temporal lobe with its medial structures and partial resection of the periventricular heterotopia located in the right lateral ventricle. The frequency of focal seizures after 1^st surgical treatment increased till 150 per month, bilateral seizures – up to 3–4 per month. After additional examination stereotaxic radiofrequency ablation of periventricular heterotopia on the right side was performed in 2019 in the Department of Functional Neurosurgery of the Federal Neurosurgical Center (Novosibirsk). In total 5 ablation spots were made in the periventricular heterotopia. Follow‑up period was 14 months. Right after the operation a transient left‑sided hemiparesis has developed (up to 4 score of MRC scale) which regressed by the time of discharge. During 14 months of the follow‑up period the patient had 3 bilateral tonic‑clonic seizures, however, after 2^nd surgical treatment focal seizures did not appear.

Conclusion. This clinical case demonstrates sufficient efficacy and relative safety of radiofrequency ablation of periventricular heterotopia in drug‑resistant epilepsy.

Background. Breast cancer contributed to 11.8 % of all the oncological diseases detected in Russia in 2020 and to 21.7 % of tumors detected among women. The frequency of brain metastases is estimated at 13–32 %. It is known that HER2 positive and triple negative breast cancers metastasize to the brain more frequently.

Aim. To present the case of stereotactic high‑dose irradiation for a large brainstem metastasis from HER2 positive breast cancer and re‑irradiation of the recurrence.

Materials and methods. Analysis of the results of stereotactic irradiation for a large brainstem metastasis from HER2 positive breast cancer and re‑irradiation of the recurrence with a local control over five years was performed.

Results. The local control after five years did not show any signs of tumor progression or post‑radiation necrosis. The patient’s Karnofsky Performance Status was estimated at 100 points.

Conclusions. The case shows the necessity of highly conformal stereotactic dose delivery to the tumor, precise determination of tumor boundaries on high resolution thin slice magnetic resonance imaging, verification of recurrence using metabolic studies and hypofractionated dose delivery. It remains open whether and to what extent target therapy may contribute to local control.

Background. Subdural empyemas are accumulation of pus between the dura mater and the arachnoid mater of the brain. They represent 12–25 % of all intracranial purulent‑inflammatory diseases. 70–80 % of them are located convexitaly and 10–20 % in the area of the falx cerebri. A spread of pus on the tentorium cerebellum occurs rare. Without timely treatment, that includes massive therapy with antibiotics and drainage of the subdural empyema, most of the patients die in the result of progression of the secondary purulent meningoencephalitis and dislocation of the brain.

Аim. To report the case of subdural empyema of rare localization – in the left part of the interhemispheric fissure and supratentorial space, to demonstrate the effectiveness of prolonged continuous flow drainage in treatment of the subdural empyema in this particular case.

Materials and methods. 16‑year‑old patient was admitted into the neurosurgical department of the 1‑st Republican clinical hospital of the Izhevsk city with pronounced general infectious and meningeal syndrome and paresis of the muscles of his right shin and foot. CT scans revealed frontal sinusitis and subdural empyema of the left part of the interhemispheric fissure and the supratentorial space. In addition to intravenous antibacterial therapy with vancomicyn and Meronem bifrontal cranioectomy, debridement of the frontal sinus, obliteration of it’s residual cavity with free muscle graft and external drainage of the subdural empyema with following continuous irrigation during 6 days after surgery had been performed. At the time of discharge from the neurosurgical department 16 days after the operation complete regress of the general infectious and meningeal syndrome was observed.

Results. On control examination 44 days after the surgery the patient’s condition was normal and he had no neurolog ical deficit. On the series of MRI scans preformed 6 months latter, after the cranioplasty, no remnants of the subdural empyema were revealed.

Conclusions. This clinical case demonstrates the effectiveness of the prolonged continuous flow drainage in combination with systemic antobioticotherapy and elimination of the primary source of infection within the frontal sinus in treatment of the large and deeply situated subdural empyema of rare falcotentorial localization.

Introduction. The etiology and pathogenesis of cerebral aneurysms are diverse. The rare cause of cerebral aneurysms occurrence is cardioembolism in cases of heart tumors, in particular in myxoma. Cardiac myxoma (from Latin muxa, mucus) is the most common (about 50 %) benign tumor of heart. With untimely diagnosis and absence of the disease treatment, embolisms in cerebral vessels may occur with typical symptoms of ischemic stroke as well as in some cases the myxomal aneurysms may develop. There are several theories of their origin. The myxomal aneurysms of cerebral vessels are more common in women and in the vast majority of cases they develop in carotid basins. In a quarter of cases, the disease onsets as intracranial hemorrhage caused by rupture of an oncotic (myxomal) aneurysm, that significantly exceeds the frequency of ruptures (1–3 % per year) in cases of “normal” bifurcation‑hemodynamic intracranial aneurysms. The mortality rate is 3.4 %. The majority (80 %) of ruptures were observed within 2 years after the diagnosis of cardiac myxoma, and in half (48.6 %) of cases clinically significant episodes of embolism were noted. Timely treatment can prevent the hemor rhagic type of course of these aneurysms. Various methods of treatment are described in the literature: different options for surgical eradication as well as the possibilities of chemotherapy and radiation exposure.

Aim. To present a case of successful radical reconstructive endovascular treatment of patient with distal cerebral aneurysm associated with cardiac myxoma, combined with presence of multiple cavernous malformations and also to highlight issues of diagnosis, differential diagnosis and existing treatment options for these diseases.

Clinical observation. The article presents a clinical observation of multiple aneurysms associated with myxoma of the heart in combination with multiple cavernous angiomas of the brain. The possibility of reconstructive eradication of distal aneurysm after its transformation from fusiform to saccular is demonstrated. The etiology and pathogenesis of occurrence, the nuances of differential diagnosis, possible methods and the algorithm for choosing a method for treating brain aneurysms associated with myxomas are reflected. The patient underwent reconstructive aneurysm shutdown by embolization with microspirals, which became possible due to the anatomical shape that favored this type of treatment. Conversion to destructive intervention was not required. Due to the natural course of the disease, the patient remains at risk of progression of a distal aneurysm in the basin of the same artery, and therefore it will be observed in dynamics.

Conclusion. All patients with cardiac myxomas, both before and in dynamics after their removal, are recommended to perform noninvasive visualization of brain vessels for verification of such complication as metastatic (myxomal) aneurysms. The prognosis in most patients with multiple intracranial aneurysms associated with myxoma is favorable and most aneurysms associated with myxoma are stable. However, in cases with progressive or ruptured aneurysms, surgical treatment options should be considered including microsurgical or endovascular eradication. Radiation and chemotherapy methods may have a certain therapeutic value.

Introduction. Injuries to the brachial plexus are one of the most severe types of injuries to the nerves of the upper limb, and variants with the separation of the roots from the spinal cord represent a very difficult category of injuries to treat. Among patients who have received such injuries, there is a very high incidence of disability, since it is possible to achieve only partial restoration of the function of the upper limb. Recently, the method of transposition of functioning muscles has been growing in popularity due to its reliability and relatively short recovery time of function.

The purpose of the work is to analyze the literature data on the possibility of using the method of transposition of functioning muscles in the complex treatment of victims with brachial plexus injuries.

The authors have searched PubMed and RSCI databases over the past 25 years for keywords: peripheral nerve damage, tendon transposition, transposition of functioning muscles, nerve injury, brachial plexus injury, spinal cord root avulsion. In the selected 23 most relevant papers, the muscles used for transposition, indications and timing of operations, results and complications were analyzed, compared with other methods of surgical treatment of brachial plexus injuries. The analysis of studies has shown that the transposition of functioning muscles allows in most cases to restore the target movement to the useful level of M3–M4 on the MRC scale, is a more reliable method and allows achieving better results, especially in patients with severe complete injuries of the brachial plexus. An important disadvantage of free hip thin muscle transplantation operations is the risk of microanastomosis thrombosis, which requires detailed preoperative planning and good microsurgical technique of the operating team.

Conclusion. Free transplantation of 2 functioning muscles is currently the method of choice for restoring upper limb movements in patients with complete brachial plexus injuries.

Background. In the structure of severe combined trauma, injuries to the pelvic bones, especially the sacrum, are relatively rare but increase steadily with the scientific and technological progress and the urbanization. Despite the widespread use of modern diagnostic methods, such as computer and magnetic resonance imaging, and the ubiquity of X‑ray diagnostics, sacral fractures are diagnosed not in all patients or not in full. In 50 % of patients, sacral fractures are not diagnosed during the initial examination, including anteroposterior X‑ray examination. In addition, in 30 % of the patients, sacral fractures are recognized on a pelvic X‑ray film incorrectly, and the long‑term outcomes of their treatment are unsatisfactory from 30 to 60 % of the cases.

Aim. To analyze scientific published sources on the issues of diagnosis, clinical picture, and treatment of patients with severe combined trauma and unstable sacral fractures.

Materials and methods. The data of 232 domestic and foreign publications from 1971 to 2020. We present the epidemiology of combined trauma and unstable sacral fractures, consider various classifications, and describe the clinical course and tactics in conservative and surgical treatment of vertically unstable fractures in the posterior pelvic ring.

Results. Many foreign publications describe both diagnostics and various methods of treatment for unstable pelvic ring injuries. The publications cover various aspects of diagnosis, clinical course, management tactics, extent and timing of surgery, and conservative treatment for sacral fractures. However, only a few publications in Russian discuss features of diagnostic search, the timing and extent of surgery, as well as the choice of the final tactics to treat patients with sacral fractures.

Conclusions. It is necessary to study the problem of diagnosis and treatment of severe combined trauma and vertically unstable fractures of the posterior pelvic ring to develop optimal diagnostic algorithms and final treatment tactics aimed at reduction of the frequency of errors, complications, and deaths, and at improvement in the quality of life of such patients.