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

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

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

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

[Spinal CSF-venous fistula: case report and literature review]. / Spinal'naya likvoro-venoznaya fistula kak prichina sindroma spontannoi vnutricherepnoi gipotenzii: sluchai iz praktiki i obzor literatury.

Syndrome of spontaneous intracranial hypotension is increasingly described in the literature as a multifactorial disease with impairment of the quality of life and risk of mortality. CSF-venous fistula as a cause of intracranial hypotension syndrome is extremely rare and requires complex diagnosis and timely surgical treatment. OBJECTIVE: We present a 55-year-old patient with acute spontaneous intracranial hypotension and spinal CSF-venous fistula. Literature data are also analyzed. RESULTS: Algorithm for diagnosis and efficacy of microsurgical resection of CSF-venous fistula is demonstrated. CONCLUSION: Intracranial hypotension following spinal fistula requires careful examination. Accurate understanding of pathophysiological and anatomical features of this disease is necessary to select an effective treatment method.

[Higher efficacy of botulinum toxin therapy for hemifacial spasm recurrence after vascular decompression. Case report and literature review]. / Uvelichenie effektivnosti botulinoterapii pri vozvrate simptomov gemifatsial'nogo spazma posle vaskulyarnoi dekompressii. Klinicheskii sluchai i obzor literatury.

Hemifacial spasm (HFS) is an involuntary synchronous tonic and/or clonic contraction of mimic muscles following ipsilateral facial nerve dysfunction. The last one is a result of neurovascular conflict between the facial nerve and vessel. Currently, vascular decompression is a pathogenetic treatment modality for primary HFS. Various authors describe postoperative recurrence of HFS, and botulinum toxin therapy remains the only option for these patients. We aimed to describe the efficacy of botulinum toxin therapy in patients with HFS recurrence after surgical vascular decompression. The article presents a female patient with a long-term history of HFS and botulinum toxin therapy (with different formulations). Efficacy of therapy gradually decreased (progressive reduction of intervals between injections). MRI revealed a close relationship between posterior inferior cerebellar artery and roots of acoustic-facial nerves near the brainstem. The patient underwent vascular decompression of the left facial nerve root under intraoperative monitoring with positive postoperative outcome. However, HFS symptoms recurred in 3 days after surgery. Botulinum toxin type A (BTA) injections were resumed with significant positive effect that can be explained by reduction of one of the factors involved into HFS. Thus, patients with HFS recurrence after vascular decompression may benefit from BTA therapy.

[Rosai-Dorfman intracranial histiocytosis: case report and literature review]. / Intrakranial'nyi gistiotsitoz Rozai­Dorfmana: sluchai iz praktiki i obzor literatury.

Histiocytosis is a group of idiopathic diseases accompanied by metabolic disorders and accumulation of metabolic products in histiocytes. Isolated Rosai-Dorfman histiocytosis of central nervous system is observed in less than 5% of cases. The authors report treatment and follow-up of a patient with intracranial Rosai-Dorfman disease. There were symptoms of lesion of the left cerebellopontine angle and epileptic seizures. Preoperative MRI identified two tumors (posterior cranial fossa on the left and right-sided parasagittal neoplasm). The authors carried out total resection of supratentorial tumor, after 3 weeks - subtotal resection of tumor in posterior cranial fossa. No recurrence after total resection was observed. Irradiation of infratentorial tumor with a total focal dose of 50 Gy after 6 months resulted tumor shrinkage throughout 12 months. Radiotherapy with the same dose was repeated throughout subsequent 12-month follow-up period due to progression of this focus. This treatment had a positive effect, but new skull base foci occurred. The authors emphasize the effectiveness of total resection and lower efficiency of subtotal excision combined with radiotherapy.

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

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

Assessment of the Cytotoxicity of Peptide Modifications of Doxorubicin on Tetrahymena pyriformis.

The cytotoxicity of doxorubicin (Dox) and its peptide modifications Z-Gly-Pro-Dox and Boc-Gly-Pro-Dox were studied. Tetrahymena pyriformis was used as a test system, which made it possible, due to the short life cycle and high reproduction rate of ciliates, to trace their response to the effects of toxicants over several generations. It was found that peptide modification of the Dox molecule markedly reduces its cytotoxic and cytostatic effect. The Z-Gly-Pro-Dox modification has less cytotoxic and cytostatic effect compared to Boc-Gly-Pro-Dox. When determining the ability of drugs (at a concentration of 100 µM) to prevent bacterial contamination of samples, it was shown that the smallest degree of overgrowth was recorded in the presence of Dox (OD600nm 81.1). Boc-Gly-Pro-Dox also had a bacteriostatic effect, though less pronounced (OD600nm 93.8). The degree of overgrowth in the presence of Z-Gly-Pro-Dox was close to that of distilled water. The results obtained on ciliates did not contradict the data obtained in similar studies on mice.

[Value of computer tomographic characteristics of the ventricles of the brain and cerebral hemocirculation in forensic medical examination of mild traumatic brain injury]. / Znachenie komp'yuterno-tomograficheskoi kharakteristiki zheludochkov golovnogo mozga i tserebral'noi gemotsirkulyatsii v sudebno-meditsinskoi ekspertize legkoi cherepno-mozgovoi travmy.

Aim of this study is to determine the changes in the parameters of the ventricles of the brain and cerebral hemodynamics to improve the diagnosis of mild traumatic brain injury. A decrease in the parameters of the lateral ventricles in combination with diffuse cerebral hypoperfusion was found. Focal disorders of cerebral circulation in the frontal and temporal lobes were registered in patients with brain injury. The algorithm of differential diagnosis of mild concussion and brain injury was developed.

[Study of stability of proline-containing derivatives of dopamine and serotonin in the biological media in vitro experiments]. / Issledovanie ustoichivosti prolinsoderzhashchikh proizvodnykh dofamina i serotonina v biologicheskikh sredakh v éksperimentakh in vitro.

Boc-Gly-Pro-DP, Z-Gly-Pro-DP, LA-Gly-Pro-DP, Boc-Gly-Pro-Srt, Z-Gly-Pro-Srt were synthesized for the first time. The stability of these compounds in the presence of leucine aminopeptidase, carboxypeptidase Y, carboxypeptidase B and proline endopeptidase (PEP) was determined. It turned out that the compounds are stable in the presence of aminopeptidases and carboxypeptidases. In the presence of PEP, dopamine (DP) and serotonin (Srt) are cleaved from the synthesized preparations. Thus, new proline-containing Srt and DP derivatives were obtained, Srt and DP could be gradually released from them. This suggest the possibility of a prolonged action of these biologically active compounds on the vital activity of cells and, consequently, of the whole organism.

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

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

Efficiency of Penetration of Dopamine and Serotonin Peptide Derivatives through the Artificial Membranes.

A mass spectrometric method has been developed for determining the content of dopamine and serotonin derivatives, which allows evaluating the efficiency of their penetration through artificial membranes depending on the structure of their peptide fragment. In this case, the diffusion of dopamine and serotonin derivatives through the membrane occurred as a result of competitive interactions. It was shown which compounds in this mixture more easily penetrate through artificial membranes. It was found that the most promising in terms of overcoming the BBB are Boc-Pro-Srt and Boc-Pro-DOPA.

[An unusual case of the severing of a passenger's leg in an automobile accident]. / Neobychnyi sluchai otchleneniia nizhnei konechnosti pri travme v salone avtomobilia.

A forensic medical examination of a corpse, whose right leg was completely separated from the body in the pelvic region during a traffic accident, was conducted. At the time of the accident, the victim was a passenger in the rear seat of a passenger car. The examination failed to establish fault for the circumstances of the injury. From the materials of the criminal case it appears that the car hit a metal guard rail, which 'penetrated' the front of the car through a hole in the damaged part of the grille and crossed the interior of the car between the driver's and passenger's seats. It was concluded that to promptly address the issue of the cause of these kinds of peculiar injuries, the participation of a forensic expert in examining the scene of a traffic accident is necessary.

[Stability of prolin-containing peptides in biological media]. / Ustoichivost' prolinsoderzhashchikh peptidov v biologicheskikh sredakh.

New data on peptide drugs have been summarized; their high stability is due to both the introduction of Pro-Gly-Pro in various amino acid sequences and the modification of the glyproline fragment itself. Pro-Gly-Pro-Leu, ACTH(6-9)Pro-Gly-Pro, 5-oxo-Pro-Arg-Pro and 5-oxo-Pro-His-Pro-NH2 were used as proline-containing peptides. Tritiated peptides were obtained: Pro-Gly-Pro-Leu with specific radioactivity of 135 Ci/mmol, ACTH(6-9)Pro-Gly-Pro - 26 Ci/mmol, 5-oxo-Pro-Arg-Pro - 60 Ci/mmol and 5-oxo-Pro-His-Pro-NH2 - 75 Ci/mmol. The concentration of Pro-Gly-Pro-Leu, ACTH(6-9)Pro-Gly-Pro, 5-oxo-Pro-Arg-Pro and 5-oxo-Pro-His-Pro-NH2 in the blood was found to be about 200 times more than in the brain for intranasal administration, and in average 600 times more for intravenous administration. The stability of proline-containing peptides in vitro experiments was determined using different commercially available peptidases (leucine aminopeptidases, dipeptidases, carboxypeptidases B and Y), and using nasal mucus, microsomal fraction of the rat brain (IMPC) and rat blood plasma. During peptidase hydrolysis of Pro-Gly-Pro-Leu, the main metabolites were Gly-Pro-Leu, Pro-Gly-Pro, Gly-Pro and Pro-Gly. For ACTH(6-9)Pro-Gly-Pro, the main metabolites were Phe-Arg-Trp-Pro-Gly-Pro and Trp-Pro-Gly-Pro. In peptidase hydrolysis of 5-oxo-Pro-His-Pro-NH2, the major metabolite was 5-oxo-Pro-His-Pro. It was shown that with different methods of peptides administration the composition of the metabolites formed is different. Based on the data obtained, resistance to enzymatic cleavage of peptides and their metabolic pathways were evaluated. Thus, these new data have shown that the above approaches can be used to prolong the action of glyprolines in living objects. In this case, the degradation of proline-containing peptides occurs mainly not due to the action of proteases, but due to other ways of degradation. In general, the data presented in the review indicate the promise of intranasal way of introducing biologically active peptides into the brain of living organisms.

[The causes of late diagnostics of vestibular shwannomas]. / Prichiny pozdnei diagnostiki vestibuliarnykh shvannom.

AIM: The objective of the present study was to elucidate the causes of late diagnostics of vestibular shwannomas based on the results of the analysis of the medical histories of the patients admitted to the Academician N.N. Burdenko National Medical Research Centre of Neurosurgery for the management of this condition. MATERIAL AND METHODS: We undertook the retrospective review of a series of 192 cases of vestibular shwannomas in the patients treated based at the N.N. Burdenko National Medical Research Centre of Neurosurgery in 2015. The study included the analysis of demographic characteristics of the patients as well as their anamnestic and clinical data. RESULTS AND DISCUSSION: A total of 55 (29%) patients were found to have small tumours (Samii T1-T3) whereas 137 (71%) ones presented with giant neoplasms including T4a and T4b tumours (in accordance with the Samii classification) in 63 (33%) and 74 (38%) patients respectively. The duration of the disease from the appearance of its first clinical symptoms up to the establishment of the definitive diagnosis was 41 months on the average. 37 (19%) patients appeared to have paid no attention to the unilateral impairment of hearing. 46 (24%) patients applied for the medical assistance to the therapists and neurologists. 56 (29%) patients had remained for a long time under the supervision of the ENT specialists and surdologists based at the local outpatient facilities. CONCLUSION: More than 2/3 of the examined patients presenting with vestibular shwannomas apply for the medical assistance at the late stages of the disease. Such situation can be attributed to the low level of oncological alertness among the general population and health providers, the poor awareness of the general practitioners and otorhinolaryngologists about this pathology, the unavailability or inefficient application of the modern neurovisualization technologies, in the first place magnetic resonance imaging. The problems encountered in connection with the performance of screening studies give evidence of the necessity of the introduction of up-to-date otoneurological and audiological investigations as well as the neurovisualization techniques into the everyday clinical practice for the comprehensive examination of all the patients suffering from unilateral hearing loss.

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

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

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

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

Synthesis of N-acyl derivatives of Pro-Gly-Pro-Leu peptide: Proteolytic stability in vitro and effects on mouse macrophage cells RAW264.7.

Acetyl, oleoyl, arachidonoyl, and docosahexaenoyl derivatives of the Pro-Gly-Pro-Leu peptide with a chemical purity of 99.8% were synthesized. The degradation kinetics of the Pro-Gly-Pro-Leu derivatives under the action of leucine aminopeptidase, nasal mucus, and microsomal fraction of the brain and blood of rats was studied. It was shown that the N-acyl derivatives of Pro-Gly-Pro-Leu proved to be more resistant to the action of leucine aminopeptidase and other enzyme systems. The study of the cytotoxic and anti-inflammatory activity of preparations on the mouse macrophage cell line RAW264.7 showed that acylation with oleic and arachidonic acid makes the peptide cytotoxic with LC50 in the range of 70-15 µM and gives it anti-inflammatory properties with EC50 of 32 and 36 µM, respectively.

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

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

[Surgical treatment of acoustic neuromas (vestibular schwannomas)]. / Khirurgicheskoe lechenie nevrinom slukhovogo nerva (vestibuliarnykh shvannom).

Clinical guidelines are topical systematically developed provisions designed to help the doctor make a decision about a treatment approach in certain clinical situations; they provide information on conducting diagnostic and screening tests, the amount of medical and surgical care, and other aspects of clinical practice. Vestibular schwannomas account for 8% of all intracranial lesions, up to 30% of posterior cranial fossa tumors, and 85% of cerebellopontine angle tumors. The incidence rate of acoustic neuromas is approximately 1 case per 100000 population per year. The paper addresses the issues of classification, diagnosis, and treatment of acoustic neuromas. The guidelines discuss in detail the key aspects of formulation of clinical diagnosis, classification features, definition of the indications for surgical or radiation treatment, and principles of expectant treatment in vestibular schwannomas. The article pays particular attention to surgical treatment of acoustic neuromas and describes the criteria for choosing a surgical approach, use of modern surgical equipment, and stages of tumor resection. On the basis of the accepted clinical classification, we propose the algorithms of action depending on the disease stage, pathological process dynamics, patient's age, and clinical manifestations. The key points of the clinical guidelines rely on evidence-based criteria. The work is intended for neurosurgery practitioners.