[Features of ictal and interictal electrical activity in assessment of the epileptogenic zone in children with focal cortical dysplasias]. / Osobennosti iktal'noi i interiktal'noi élektricheskoi aktivnosti v otsenke épileptogennoi zony u detei s fokal'nymi kortikal'nymi displaziiami.

Currently, there is no single standard defining what rhythmic activity should be considered as the area of ictal pattern onset. Differences in electroencephalographic patterns associated with different types of focal cortical dysplasias (FCDs) have not been defined. Aim - we aimed to identify features of the ictal onset pattern on a scalp EEG, depending on the histology, location, and extension of epileptogenic zone, as well as to elucidate the relationship between concordance of the interictal and ictal activity localization and ictal onset pattern types. MATERIAL AND METHODS: We studied scalp video-EEG monitoring data of 38 FCD patients who underwent surgical treatment for intractable epilepsy in the period between 2010 and 2016. We analyzed the data on interictal and ictal activity localization and compared them with the data on FCD types and lesion location. RESULTS: Two types of the ictal onset pattern on EEG, local and generalized, were identified. The local and generalized types included two and four variants of the ictal onset pattern, respectively. Therefore, 6 combinations of rhythmic activity were identified, which manifested within the first 10 s after the onset of electrographic changes on EEG simultaneously with initial clinical manifestations of seizure. Co-localization of the interictal and ictal activity zones occurred in 42% of cases; of these, 88% of patients had the ictal onset pattern. In the remaining cases (58%), no co-localization of the interictal and ictal activity zones was detected; of these, 76% of patients were assigned to the group with the generalized ictal onset pattern. The local ictal onset pattern was more common in patients with type II FCD, while the generalized ictal onset pattern was more common in patients with type I and type III FCD. No correlation between the ictal onset pattern type and the lesion localization was found. CONCLUSION: We describe two ictal onset pattern types, local and generalized, on EEG in children with FCD. The co-localization of ictal and interictal activity zones prevails in the local ictal onset pattern group. The local ictal onset pattern is often associated with type II FCD. In the case of type I and type III FCD, the generalized ictal onset pattern predominates. There is no clear relationship between the ictal onset pattern type and the lesion location.

[Hemispherectomy in the treatment of pediatric symptomatic epilepsy of children]. / Gemisferektomiya v lechenii simptomaticheskoi epilepsii u detei.

INTRODUCTION AND PURPOSE: Hemispherectomy is a recognized option in the treatment of symptomatic forms of intractable focal epilepsy in patients with developmental brain malformations and some acquired lesions of one the hemispheres. The prognosis for an outcome of the technique is important in terms of the indications for surgical treatment. MATERIAL AND METHODS: We described the hemispherectomy technique and its variants and analyzed our own experience of surgery in 40 children. The most common (27 cases) brain pathology was extended unilateral cortical dysplasia with polymicro- or pachygyria and consequences of perinatal stroke. Six children had Rasmussen encephalitis; 6 patients had hemimegalencephaly; 1 child with Sturge-Weber syndrome had angiomatosis of the soft meninges. The patients' mean age was 3 years. Functional hemispherectomy (hemispherotomy) was used in most cases (37); 3 patients underwent anatomical hemispherectomy. RESULTS: At the time of discharge, seizures resolved in all patients; later, no seizure recurrence was observed in 25 out of 29 cases with known follow-up (the follow-up median was 2.5 years), which corresponded to class 1 outcomes on the ILAE scale (86%). Serious complications developed in 2 cases; 1 patient died; hydrocephalus and the need for bypass surgery occurred in other 2 children. These results are discussed along with the literature data, and the indications for hemispherectomy are provided. CONCLUSION: Hemispherectomy is a reliable and effective technique for treatment of symptomatic hemispheric forms of epilepsy in children. More than in 80% of patients with congenital or acquired pathology of one of the cerebral hemispheres, its deafferentation or resection leads to persistent elimination of seizures. Children with severe forms of intractable epilepsy should be promptly referred to dedicated centers to address the issue of advisability of surgical treatment.

[Comparison of electrocorticographic patterns with focal cortical dysplasia types in children with epilepsy].

OBJECTIVE: the objective of the study was to determine significant differences in electrocorticographic patterns for various types of focal cortical dysplasias. MATERIAL AND METHODS: 42 patients diagnosed with drug-resistant focal epilepsy were operated on at the Burdenko Neurosurgical Institute in the period from 2006 to 2013. Patients who were histologically diagnosed with focal cortical dysplasia (FCD) and underwent video-electroencephalography and electrocorticography were analyzed. RESULTS: The classification of epileptiform patterns proposed by Palmini in 1995 was used. The sporadic epileptiform activity pattern was predominant in electrocorticographic studies. The continued pattern was more frequent in the case of type II focal cortical dysplasias (FCDs), both combined and isolated; burst and sporadic activity patterns prevailed in combinations in the case of type III FCDs. A uniform distribution of all pattern types of the epileptiform activity was observed in type I FCDs. The data are statistically significant for groups with sporadic and continued patterns. CONCLUSION: The continued epileptiform activity pattern is predominant in type II focal cortical dysplasia that corresponds to the most pronounced epileptogenesis processes of brain tissue with the presence of pathological forms of neurons. A uniform pattern distribution is observed for type I FCD. Patterns of the epileptiform activity and sporadic spike bursts are predominant in the case of type III FCDs. The sporadic activity is likely to be non-specific and almost uniformly distributed in all types of cortical dysplasias.

Local epileptic activity, histological and neuroimaging findings in symptomatic epilepsy.

OBJECTIVE: This study is aimed at revealing the relationship between local interictal epileptic activity, cytoarchitectural disturbances and magnetic resonance imaging (MRI) findings. MATERIAL AND METHODS: We prospectively investigated a series of 25 patients with symptomatic epilepsy due to isolated forms of focal cortical dysplasia (FCD) or hippocampal sclerosis and low-grade tumours associated with FCD, all of whom underwent tailored surgical procedures under intraoperative electrocorticography; we conducted neuropathological examinations of 92 biopsies taken from different places. We examined the relationship between dysplastic changes in the cortex and the absence or presence of seizure patterns (SPs), including regular spikes/sharp waves, recruiting discharges, paroxysmal fast activity and rhythmic delta-theta activity. Comparisons with MRI findings were also performed. RESULTS: Complete removal of the SPs zone was associated with better results of surgical treatment. Areas with isolated architectural abnormalities were associated with SPs significantly more often than those where the cortex contains immature or giant neurons; these areas were associated with SPs more than areas containing dysmorphic neurons. The extent of MRI signs appearance in the neocortex correlated neither with the presence of SPs nor with the types of histological changes. CONCLUSIONS: We suppose an inverse relationship between the morphological changes in neurons and their ability to generate epileptic activity. Electrocorticography may be used for the identification of the MRI-negative epileptogenic lesions.

[Magnetoencephalography in the presurgical evaluation of patients with drug-resistant epilepsy].

Magnetoencephalography (MEG) in combination with structural MRI (magnetic source imaging, MSI) plays an increasingly important role as one of the tools for presurgical evaluation of medically intractable focal epilepsy. The aim of the study was to compare the MSI and commonly used video EEG monitoring method (vEEG) in their sensitivity to interictal epileptic discharges (IED) in 22 patients with drug resistant epilepsy. Furthermore, the detection and localization results obtained by both methods were verified using the data of electrocorticography (ECoG) and postsurgical outcome in 13 patients who underwent invasive EEG monitoring and surgery. The results showed that MSI was superior to vEEC in terms of sensitivity to IED with difference in sensitivity of 22%. The data also suggested that MSI superiority to vEEG in detecting epileptic discharges might, at least partly, arise from better MEG responsiveness to epileptic events coming from the medial, opercular and basal aspects of cortical lobes. MSI localization estimates were in the same cortical lobe and at the same lobar aspects as the epileptic foci detected by ECoG in all patients. Thus, magnetic source imaging can provide critical localization information that is not available when other noninvasive methods, such as vEEG and MRI, are used.

Relationship between epileptogenesis and morphological changes in the cerebral cortex.

The relationship between disorders in the cytoarchitectonics (microdysgenesis) and formation of epileptogenic zones was studied on clinical material. Results of surgical treatment of 29 patients with drug-resistant temporal epilepsy are presented. Intraoperative electrocorticography was carried out in all patients. Histological studies of the cortex from the zone of regular epileptic activity registration were carried out in 23 cases. A relationship between completeness of radical removal of the zone of regular epileptic activity and treatment results was detected. Histological studies of resected cortex revealed signs of microdysgenesis in all cases. The presence of similar changes in the zone of regular epileptic activity registration, resection of which is essential for attack control, suggests a pathogenetic relationship between microdysgenesis and generation of epileptic activity.

[Surgical tactics for the treatment of symptomatic temporal lobe epilepsy].

The results of treatment were analyzed in 40 patients aged 5 to 43 years who had been operated on for symptomatic temporal lobe epilepsy, among them there were 29 patients with low-grade intracerebral tumors. Local and regional lesions were observed in 27 and 13 cases, respectively. Thirteen patients with local lesions had also a local type of epileptiform activity; the remaining had a regional type. The involved area was removed in 10 patients; in 15 cases that was removed, with the areas wherein epileptform activity persisted; 15 patients underwent temporal lobectomy adapted to the data of neurophysiological study made before resection. Magnetic resonance imaging indicated that the involved area was completely removed; in 18 patients the resection borders exceeded the involved area. In local lesions accompanied by local epileptic activity, there were no significant differences between the removal in the borders of a lesion and that in a greater extent (p > 0.05). In patients with regional epileptiform activity, the results of treatment with removal in the greater extent were significantly better (p < or = 0.01). In these patients, an association was found between the significant disturbances of normal cortical rhythm outside the visualized involved area and the severe impairments in the cortical cytoarchitectonics in these areas. Persistent epileptic activity along with cortical rhythm disturbances on an electrocorticogram may be as a sign of lesion spread outside the visible borders and an indication for additional resections.

[Pharmacoresistant temporal epilepsy: surgical treatment and analysis of factors influencing on its results].

An objective of the study is an analysis of the results of surgical treatment and influence of resection volume on the treatment outcome. Sixty-four patients, aged 7-46 years, with an epileptic focus in a temporal lobe have been studied. Patients have been stratified into 2 groups. The first group included 55 patients with epileptogenic lesions of a temporal lobe (monoregional lesions) and the second one--9 patients who, along with the lesion of one temporal lobe, had the signs of lesions in other brain areas (multiregional lesions). In the group of patients with monoregional lesions, a resection of the affected area has been performed. In other patients, the techniques of resection of frontal-medial temporal lobe regions within the scope of the area of steady epileptiform activity have been used. The results have been assessed with the modified Engel scale: class I--an absence of clinically manifested seizures (auras are possible); class II--seizures that do not impact quality of life; class III--a decrease of seizures frequency by more than 80%; class IV--an absence of substantial improvement. In the monoregional lesions, the satisfactory results (I-II classes) were observed in 39 patients (74%), including outcomes of class I (28 patients). In other 16 cases outcomes of classes III and IV were observed. In the multiregional lesions and cryptogenic (possibly symptomatic) partial epilepsy, outcomes of classes III and IV were observed in all patients, regardless of the resection volume. In conclusion, the highest efficacy with regard to frequency and severity of seizures is achieved by resections including the whole area of visualized lesion and border-line area of steady epileptic activity, the identification of which demands the intrasurgery neurophysiologic study. In the extensive and multiregional lesions, the resection surgery confined to one temporal lobe has low effect.

[Analysis of factors influencing the prediction of surgical treatment for symptomatic temporal lobe epilepsy].

The results of treatment were analyzed in 37 patients with drug-resistant symptomatic temporal lobe epilepsy among whom there were 22 patients with low-grade intracellular tumors, 2 with cavernomas; 6 with cortical malformations, and 9 with residual organic lesions. Double pathology was noted in 4 patients. Mono- and multiregional lesions were observed in 30 cases. Removal of the site of lesion, extended medial resections, and temporal lobectomy were performed in 7, 5, and 25 cases, respectively. There was an association of the quality of outcomes with the scope of an intervention: the best results were achieved when the affected area with adjacent cortical portions was completely removed within the eliptogenic area. Resections for multiregional lesions are low effective.

[Preoperative neurophysiological study of patients with epilepsy caused by damage to the temporal lobe].

The paper deals with the development and substantiation of various neurophysiological procedures during preoperative examination of patients with symptomatic epilepsy. The neurophysiological findings of 133 patients with drug-resistant temporal lobe epilepsy were applied. Unprogressive damage to the medial portions of the temporal lobe was verified in 18 patients. Low- and higher-grade malignancy of the temporal lobe was confirmed in 91 and 24 patients, respectively. This yielded an algorithm of the optimum neurophysiological preoperative examination. Emphasis is laid on the differences in applied procedures depending on the side of organic lesion location. Thus, the use of the developed algorithm makes it possible to lighten the selection of candidates for surgical treatment of drug-resistant symptomatic epilepsy and to optimize the examination of epileptic patients with different types of brain damage.

[Analysis of the results of surgical treatment for symptomatic epilepsy caused by temporal lobar neoplasms]. / Analiz rezul'tatov khirurgicheskogo lecheniia simptomaticheskoi épilepsii, obuslovlennoi novoobrazovaniiami visochnoi oblasti.

The present study involves the analysis of the results of surgical treatment in 35 patients with drug-resistant epilepsy caused by local temporal lobar lesions: glioma without growth (n = 31), gliosis (n = 1), and cavernoma (n = 3). The medial location of neoplasms involving the hippocampus was noted in 25 cases, their extrahippocampal location was observed in 10 cases. The history of seizures was 2 to 18 years; the duration of a postoperative follow-up was 1 to 6 years. Electrocorticographic and EEG findings indicated that in all cases the eliptogenic zone was located in the medial portions of the temporal lobes at the site of lesion. The first stage of surgery was to remove a neoplasm; the adjacent portions of an epileptogenic zone were resected only with preserved convulsive activity in the surrounding areas. Good results (Classes I-II) were observed in cases of the medial location of a lesion in both total removal of a neoplasm and additional resections; in the group of patients the results were better than in routine removal (seizures ceasing in 4 of 5 and in 3 of 12 patients, respectively). Bad results (Classes III-V) were noted with partial removal of a neoplasm from the medial portions (n = 4), there were much better results (Classes I-II) with its total removal from the medial portions and with its partial removal from other areas. With total removal of extrahippocampal neoplasms, seizures were retained (Classes III-IV); additional resections of neocortical zones (n = 2) failed to improve the results of treatment. With resections in the entorial cortical area, the results were better (Class II). Our findings confirm that hippocampal removal plays an important role in symptomatic temporal epilepsy for an adequate monitoring of seizures.

[Effect of lysozyme on the growth of murine lymphoma and antineoplastic activity of cyclophosphamide]. / Vliianie lizotsima na rost myshinoi limfomy i protivoopukholevuiu aktivnost' tsiklofosfamida.

It was shown that hen egg-white lysozyme (LM) in the dose 100 mg/kg under the daily intragastral use slightly inhibited tumor grown or did not influence significantly upon it and did not change antitumor activity of cyclophosphamide. When used at mice C57Bl/6J with the transplanted ascitic or solid T-cell lymphoma EL4 (syngeneic system). On model of the same tumors in ascitic form at mice-hybrids (C57Bl/6J x DBA2)F1 (semisingeneic system) LM significantly potentiates antitumor activity of cyclophosphamide, though it had no effect on the rate of tumor growth. Potentiation of the effect of cyclophosphamide revealed itself in more slow development of ascite, increased mean life-span and the overall survival, appearance of completely cured animals. Our clinic-laboratory studies have revealed a sharp deficit of endogenic lysozyme in the blood serum of leukemic patients and extremely low lysozyme content in lavage liquid, from leukemic patients, with pneumonia. These data suggest that LM can be useful as a food additive in the complex treatment of oncological patients for enhancing antineoplastic chemotherapy efficacy.

[Experience in surgical treatment of patients with focal forms of temporal epilepsy]. / Opyt khirurgicheskogo lecheniia bol;nykh s ochagovymi formami visochnoi épilepsii.

Fifteen patients with focal lesions of temporal epilepsy were examined before and 6 months to 4 years after surgery. There were low-grade gliomas in 13 cases, muscle tissue heterotopy in 1 case, and medial temporal sclerosis in 1. Epileptogenic lesions were localized in the medial structures of the temporal lobe in 10 cases and in the lateral temporal regions in 5 cases. Comprehensive neurophysiological study, including intraoperative electrocorticography, was used to identify an epileptogenic zone (EZ). EZs were found in the medial structures on the affected side in all patients. Lesionectomies were performed in all cases. It was combined with medial resection in 12 cases (it was done in 10 patients until epileptic activity disappeared). Nine patients stopped having seizures after surgery. One patient had only auras. Improvements were slight in 5 patients. A relationship was found between the surgical outcomes and the site of a lesion and EZ. They authors conclude that complete recovery may occur in cases with medial locations of a lesion and EZ. The outcomes of surgery are much poorer in cases with the lateral sites of an lesion and in those with the medial site of EZ.

[The effect of selective dorsal rhizotomy on motor function in patients with infantile cerebral palsy]. / Vliianie selektivnoi rizotomii na dvigatel'nuiu funktsiiu bol'nykh detskim tserebral'nym paralichom.

The authors analyze the outcomes of surgical treatment in 15 CP patients with lower paraparesis who had been treated with selective dorsal rhizotomy at the L2-S2 level. All the patients were examined by neurological study, EMG, EEG, visual evoked potential (VEP) recording and motor reaction time estimation. Based on the findings, it is suggested that SPR lumbosacral spinal level may affect cerebral function. Some motor functional changes are associated with this impact. Possible mechanisms of these changes are discussed.

[Use of neurotransplantation in the treatment of Parkinson's disease]. / Ispol'zovanie neirotransplantatsii v lechenii bolezni parkinsona.

The outcomes of transplantation of the human embryonal mid-brain into the striatum of patients with Parkinson's disease are presented. For this, a procedure for obtaining, isolating, preparing the human embryonic midbrain, as well as a method for stereotactic administration of embryonal nerve tissue suspension having high dopaminergic neuron levels into the patients' striatum are specified. Patients underwent neurological examinations by the international protocol Core Assessment Program for Intracerebral Transplantation including monthly video recording within 3 months before and 3-24 months after surgery. Electrophysiological, neuropsychological, and immunological examinations were made at the same intervals. Most patients had positive dynamics: diminution of the severity of main disease symptoms, reduction in the efficiency of a single dose of DOPA-containing drugs, decrease in the magnitude of side effects of drug therapy.

[The spatial organization of bioelectrical activity during the treatment of the chronic pain syndrome]. / Prostranstvennaia organizatsiia bioélektricheskoi aktivnosti v protsesse lecheniia khronicheskogo bplevogo sindroma.

EEG studies with spectral-coherent analysis and evoked potentials recording were carried out in 35 patients with deafferentation pain syndrome before and after pain-relief surgery (DREZ operations). In the cases with a significant anti-pain effect obtained there was an increase of the mean coherence level accompanied by an increase of different frequencies rhythms correlation in symmetrical regions of both hemispheres together with a marked decrease of intrahemispheric connections, especially in the frontal-temporal areas in the theta-range. After the pain-relief surgery the late positive component of somatosensory evoked potential (P220-300) decreased and visual evoked potentials became more clearly detected. Electrophysiological results give evidence on the alterations in the nonspecific afferent system after the pain-relief surgery and weakening of emotional tension. The data may be used as an objective criterion for evaluation of efficiency of surgical interventions in patients with pain.

[The CT-stereotaxic biopsy of brain tumors]. / KT-stereotaksicheskaia biopsiia opukholei golovnogo mozga.

CT-stereotaxic biopsy is a modern method for the diagnosis of intracranial tumors. The histological diagnosis established by means of it makes it possible to choose the most rational tactics of treatment and determine more exactly the indications and contraindications for the operation. The examination was conducted on 219 patients with various brain tumors. Authentic histological information was obtained in 84% of cases, 4 patients died, a stable neurological defect developed in another 2 patients. Some methodical procedures for increasing the informativeness and reducing the risk of complications are discussed. An important component is rapid examination of part of the bioptic material by means of smears for intraoperative appraisal of its representativeness and correction of biopsy targets. Among 73 cases in which smears were examined only in 9 the findings were in disagreement with the data of the traditional histologic study, only in the degree of tumor differentiation in all of them. Stereotaxic biopsy is most expedient in situations in which the tactics and main method of treatment are determined to a greater degree by the histological structure rather than by the localization and the patient's general condition. Such cases account for one fourth of all cases of intracerebral tumors.

[The genesis of movement-related human brain potentials in different forms of motor pathology]. / Genez sviazannykh s dvizheniem potentsialov mozga cheloveka pri raznykh formakh dvigatel'noi patologii.

To study the role of subcortical structures and cerebellum nuclei in the genesis of the human brain potentials connected with motion patients were examined with parkinsonism and hyperkinetic form of children cerebral paralysis. In one group of patients the motor responses were recorded by means of long-term electrodes implanted with the medical purpose into the ventro-oral group of thalamus nuclei, subcortical nuclei and dentate cerebellum nuclei. In patients of the second group potentials, connected with motion were led from the scalp before and after one-moment destruction in the zone of the same structures. In ventro-oral and reticular thalamus nuclei lateral and medial segments of the pale globe and in the cerebellum dentate nucleus post-motor components were recorded which were considered as electrographic expression of motion realization and completion processes (P2 and N3) and also as slow negative oscillation (component N1), that pointed to participation of the studied structures not only in regulation of voluntary movement but also in the process of movement preparation. Absence of N2 component at recording motor responses from deep electrodes and its sufficient stability at scalp leads gave the reason to suggest that its genesis was connected with the cortex activity.

[Movement-related brain potentials during the treatment of parkinsonism]. / Sviazannye s dvizheniem potentsialy mozga v protsesse lecheniia parkinsonizma.

The authors studied motor associated brain potentials (MABP) in patients with disturbed motor function (hypertonia, tremor) due to affection of the basal ganglia (parkinsonism) and studied the changes of these potentials after stereotaxic operations conducted for the correction of the motor pathology. It was found that in a favourable effect of operative treatment manifested by decrease of the tonus and inhibition of tremor in patients with parkinsonism, there was a tendency towards normalization of MABP. Restoration of some of the components of the motor response and in certain cases of the MABP on the whole occurred on the 14-16th postoperative day. No clearly defined changes of motor associated potentials characteristic of different forms of parkinsonism were discovered.