[Isolated sarcoidosis of the brain]. / Izolirovannyi sarkoidoz golovnogo mozga.

Sarcoidosis is a granulomatous multisystem disease of unclear etiology. Among the many local lesions of different localization, lesions of the central and peripheral nervous system (neurosarcoidosis) are distinguished as particularly unfavorable manifestations of the disease. Only in rare cases, neurosarcoidosis can manifest as isolated or primary. Biopsy remains the gold standard for the diagnosis of neurosarcoidosis. However, significant difficulties remain in verifying the diagnosis, especially with an isolated variant of the lesion A rare case of isolated neurosarcoidosis with a primary focus in the right hemisphere of the brain is described. The data of histological, histochemical and immunohistochemical examination of the surgical material are presented.

[The phenomenon of pseudotumorous cross immunohistochemical reactivity of glia in progressive multifocal leukoencephalopathy]. / Fenomen psevdotumoroznoi perekrestnoi immunogistokhimicheskoi reaktivnosti glii pri progressiruyushchei mul'tifokal'noi leikoentsefalopatii.

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating brain damage caused by infection of oligodendrocytes and astrocytes with the lytic JC virus on the background of immunosuppression. A case report of PML with a tumor-like course is presented. Morphological diagnostics revealed non-specific staining of antibodies to Ki-67, p53, IDH1, NF and Vim in the nuclei of gliocytes affected by the JC virus. Histological examination and microscopic evaluation of the changes in the brain for the diagnosis of PML is a priority. The recommended intravital biopsy does not always help in clear verification of PML due to the limited volume of tissue fragments presented for research. For the correct interpretation of changes during an intravital pathological examination and verification of PML, it is important to take material during a stereotaxic biopsy, not only from the center, but from the edges and perifocal zone of the altered tissues for the possibility of a spatial histological assessment of the pathological process.

[Primary diffuse meningeal melanomatosis: a literature review and a case report]. / Pervichnyi diffuznyi melanomatoz myagkoi mozgovoi obolochki: obzor literatury i sobstvennoe nablyudenie.

Primary melanocytic tumors of the central nervous system (CNS) are extremely rare and account for only 1% of all melanomas and 0.05% of primary brain tumors. In case of diffusely invasive lesions of the pia mater with a tumor of melanocytic origin (without signs of extracranial metastases), the tumors are classified as primary diffuse meningeal melanomatosis (PDMM). The latter is an extremely rare subtype of CNS malignant tumor with an incidence rate of 1 in 20 million people. Despite the development of neuroimaging techniques, today a morphological examination remains the main and most accurate method for verifying CNS melanocytic tumors. The paper describes a fatal case of PMMD manifested as epileptic syndrome, with a rapidly progressive course.

[Unfavorable outcome of giant vertebral artery aneurysm. Clinical case and literature review]. / Neblagopriyatnyi iskhod techeniya gigantskoi anevrizmy pozvonochnoi arterii. Klinicheskoe nablyudenie i obzor literatury.

OBJECTIVE: To demonstrate the unfavorable natural course and prognosis of giant vertebral artery aneurysm, to analyze the literature, and to conduct a postmortem histopathological study of the features of this disease.

[Structural heterogeneity of epileptic foci in local drug-resistant epilepsy]. / Strukturnaya geterogennost' epilepticheskikh ochagov pri lokal'noi farmakorezistentnoi epilepsii.

BACKGROUND: To study etiopathogenesis is one of the most important tasks of modern neurology. Various types of structural changes occur in drug-resistant epilepsy (DRE); however, they are described as distinct phenomena. OBJECTIVE: To provide a comprehensive characterization of structural changes in the cortex and adjacent white matter in the electrophysiological activity zone (in the epileptic focus) in patients undergoing surgery for DRE. MATERIAL AND METHODS: Biopsy material of fragments of the temporal lobe and hippocampus from 16 patients aged 21 to 54 years (mean age, 25 years) with DRE were intraoperatively obtained at the Prof. A.L. Polenov Russian Research Institute of Neurosurgery. The investigators studied histological sections stained with H&E, toluidine blue according to the Nissl method and the Spielmeyer method, as well as the results of immunohistochemical reactions with glial fibrillary acidic protein (GFAP), vimentin, and neurofilaments (NF) (Dako antibodies, Denmark). RESULTS: Histological examination revealed a set of heterogeneous changes, reflecting the complex pathogenetic interactions that developed during the formation of an epileptic focus. Structural brain damage involved both gray and white matter. Focal cortical dysplasia was diagnosed in 14 (87.5%) cases; white matter neuronal heterotopia in 100%; neuronal reactive and destructive changes in 100%; epileptic leukoencephalopathy (vascular demyelination, microcysts, sclerosis and dystonia, gliosis) in 100%, cortical atrophy in 12.5%, and hippocampal sclerosis in 20% (in 2 out of the 10 examinees). CONCLUSION: The morphopathological heterogeneity in the structure of epileptic foci reflects the complexity of etiopathogenetic interactions, the polymorphism of epileptic manifestations, and the individual nature of formation of the epileptic system, which requires an integral approach to understanding the pathogenesis and morphogenesis of formation of the epileptic system and provides a direction for a personalized approach to epilepsy treatment.

Functional Imbalance of Glutamate- and GABAergic Neuronal Systems in the Pathogenesis of Focal Drug-Resistant Epilepsy in Humans.

The mechanisms of the formation of pharmacological resistance in temporal focal epilepsy remain poorly understood, and effective treatment strategies that can suppress epileptogenesis do not currently exist. We studied the imbalance between the glutamatergic (stimulating) and GABAergic (inhibitory) neuronal systems, as well as the role of apoptotic processes in the pathogenesis of drug-resistant epilepsy. To this end, the expression of Gad65, Vglut2, NR2B, Bcl-2, and caspase-8 proteins was analyzed in the gray and white matter of the temporal cortex of human brain. It was shown that pathological processes in the glutamatergic and GABAergic systems related to drug-resistant epilepsy are accompanied by changes in the content of apoptotic proteins, which can be the cause of neuronal death.