[Epilepsy surgery in children with tuberous sclerosis]. / Khirurgicheskoe lechenie epilepsii u detei s tuberoznym sklerozom.

Most children with tuberous sclerosis (TS) present with intractable seizures. Various factors including demography, clinical data and surgery option are mentioned to affect the outcome after epilepsy surgery in these cases. OBJECTIVE: To evaluate some demographic and clinical variables probably related to seizure outcome. MATERIAL AND METHODS: Thirty-three children, median age 4.2 ys (7.5 mths-16 ys), with TS and DR-epilepsy underwent surgery. Within overall 38 procedures (redo surgery was needed in 5 cases), tuberectomy (with or without perituberal cortectomy) was performed in 21 cases, lobectomy - 8, callosotomy - 3, various disconnections (anterior frontal, TPO and hemispherotomy) - 6 patients. Standard preoperative evaluation included MRI and video-EEG. Invasive recordings were used in 8 cases, coupled by MEG and SISCOM SPECT in some cases. ECOG and neuronavigation were used routinely during tuberectomies, and stimulation and mapping were employed in cases with lesions overlapping or near to eloquent cortex. Surgical complications: wound CSF leak (n=1) and hydrocephalus (n=2) were noted in 7.5% of cases. Postoperative neurological deficit (most frequently hemiparesis) developed in 12 patients, being temporary in majority of them. At the last FU (med 5.4 ys) favorable outcome (Engel I) has been achieved in 18 cases (54%), while 7 patients (15%) with persisting seizures reported less common attacks and their milder form (Engel Ib-III). Six patients were able to discontinue AED-treatment and 15 children resumed development and markedly improved in cognition and behavior. RESULTS AND CONCLUSION: Among different variables potentially influencing the outcome after epilepsy surgery in cases with TS, the most important one is seizure type. If prevalent, focal type may be a biomarker of favorable outcomes and probability to become free of seizures.

[Surgical treatment of epilepsy in children with focal cortical dysplasia in central gyri]. / Khirurgicheskoe lechenie epilepsii u detei s fokal'nymi kortikal'nymi displaziyami tsentral'nykh izvilin.

Focal cortical dysplasias are known to be the most frequent and furtive lesions leading to intractable epilepsy in children. Epilepsy surgery in central gyri, been effective in 60-70% of cases, is still significantly challenging due to the high risk of postoperative permanent neurological impairment. STUDY AIMS: Assessment of the outcome after epilepsy surgery in children with FCD in central lobules. MATERIAL AND METHODS: Nine patients, median age 3.7 ys, IQR=5.7 ys (min 1.8- max 15.7 ys) with FCD in central gyri and DR-epilepsy underwent surgery. Standard preoperative evaluation included MRI and video-EEG. Invasive recordings were used in 2 cases, coupled by fMRI in 2. An ECOG and neuronavigation, as well as stimulation and mapping of primary motor cortex were used routinely during the procedure. Gross total resection was achieved in 7 patients according to postoperative MRI. RESULTS AND CONCLUSIONS: Six patients with new or worsening of already existing hemiparesis recovered within a year after surgery. At the last FU (med 5 ys) favorable outcome (Engel class IA) has been achieved in 6 cases (66.7%), while two patients with persisting seizures reported seizing less frequently (Engel II-III). Three patients were able to discontinue AED-treatment and four children resumed development with improvement in cognition and behavior.

[Hypothalamic hamartoma microsurgical resection using transcallosal transforaminal approach]. / Mikrokhirurgicheskaya rezektsiya gipotalamicheskikh gamartom s transkalleznym transforaminal'nym dostupom.

OBJECTIVE: Transcallosal transseptal interforniceal approach is recognized as the most appropriate route to resect sessile hypothalamic hamartomas but individuals with obliterated cavum septi pellucidi may pose difficulties to access these lesions safely. MATERIAL AND METHODS: Six patients aged 8-34 years (med - 15.5) with the rather small (medial volume - 1.2 cm3) and in all but one cases the Delalande-Type II intraventricular sessile hamartomas and intractable epilepsy underwent surgery. The last patient had a rather larger lesion (Type III) encroaching both hypothalami and infundibulum. Cavum septi could not be distinguished on preop MRI in all cases. Lesions were removed via transcallosal transforaminal route using CUSA and foraminal walls dynamic retraction. In 4 cases the ipsilateral anterior septal vein was divided to expand the orifice of Monro foramen facilitating illumination and dissection. RESULTS: Early postop course was uneventful in all cases. Total or near total lesion removal was revealed on post-surgery images in cases with Type II hamartomas. No one of patients with ligated septal veins exhibited any signs of venous infarcts. Median known FU is 3 years (14 months - 5 years). Three patients were free of every seizure at the last check (50%). Two other patients nevertheless persisting mild recent memory deficit, were able to live independently and reported rare non-disabling events. AE-medication was discontinued in 2 patients, in other three cases it was tapered and simplified. CONCLUSION: In a subset of carefully selected patients with rather small Delalande-Type II sessile hypothalamic hamartomas in case of obliterated Cavum Septi Pellucidum the transcallosal transforaminal approach may be attempted in alternative to conventionally used transseptal interforniceal route with similar outcome and acceptable morbidity.

[Surgical treatment of epilepsy in patients with hypothalamic hamartomas]. / Khirurgicheskoe lechenie epilepsii u bol'nykh s gipotalamicheskimi gamartomami.

The purpose of this review was to analyze the current ideas about various techniques and methods for treating epilepsy in patients with hypothalamic hamartomas including microsurgery, endoscopy, radiofrequency thermal destruction, stereotactic laser ablation and radiosurgery. Data characterizing their effectiveness, limitations and complications are considered. CONCLUSION: When choosing the optimal treatment option, it is necessary to take into account patient age and course of disease, anatomical and topographic features of hamartoma location, previous attempts of treatment, opinion of the patient and his guardians, as well as surgical experience.

[Crossed aphasia in neurosurgical practice: case report and literature review]. / Perekrestnaya afaziya (Crossed aphasia) v neirokhirurgicheskoi praktike: opisanie sluchaev i obzor literatury.

BACKGROUND: Crossed aphasia in dexstral (CAD) is an extremely rare disorder. To date, about 200 cases have been described in the literature. MATERIAL AND METHODS: The authors report 4 cases of CAD. Luria's neuropsychological examination was carried out. Functional asymmetry in the arm was analyzed using the Annett questionnaire. MRI and intraoperative findings confirmed localization of lesion in the right hemisphere in all patients. RESULTS: A 59-year-old right-handed man developed frontotemporal aphasia after previous resection of right-sided glioblastoma of fronto-insular-temporal region. In a 31-year-old right-handed man, crossed aphasia occurred after extensive hemorrhage from arteriovenous malformation into the right frontotemporoparietal region. A 39-year-old right-handed man developed severe combined aphasia after resection of diffuse glioma of the right insular-temporal region. A 10-year-old right-handed boy developed aphasia with word forgetting after resection of a large tumor of the right temporal lobe. All patients had impaired dynamic praxis. Other cognitive functions were intact. CONCLUSION: The authors discuss possible combinations of functions in one hemisphere for both right-handers and left-handers and emphasize diverse types of functional asymmetries described in the literature. Different localizations of functions in right-handers and left-handers indicate that local zones with different methods of information processing (successive or simultaneous) can coexist in one hemisphere. Therefore, the functions requiring different processing of information (for example, speech with praxis or spatial functions) can develop in one hemisphere. Cognitive impairment depends not only on the type of functional asymmetry, but also on localization of lesion. Crossed aphasia in right-handers indicates the rarest normal type of functional brain asymmetry with localization of speech functions in the right hemisphere. Possible aphasia in right-handers following damage to homologues of speech zones in the right hemisphere can require additional examination of these patients.

[Lessons learnt from 101 hemispheric pediatric epilepsy surgeries part ii: pitfalls and complications]. / Uroki 101 gemisferotomii u detei s polusharnoi simptomaticheskoi epilepsiei. Chast' II: oslozhneniya i oshibki.

OBJECTIVE: To evaluate the spectrum of pitfalls and complications after hemisherotomy basing on a retrospective study of a large consecutive pediatric cohort of patients from a single institution. MATERIAL AND METHODS: One hundred and one patients (med. age - 43 months) with refractory seizures underwent hemispherotomy. Developmental pathology was the anatomical substrate of disorder in 42 patients. The infantile post-stroke scarring and gliosis was the origin of epilepsy in the majority of 43 cases with acquired etiology. The progressive pathology (RE, S-W and TS) was the etiology in the rest of children (16 cases). The lateral periinsular technique was used to isolate the sick hemisphere in 55 patients; the vertical parasagittal approach was employed in 46 cases. Median perioperative blood loss constituted 10.5 ml/kg, but was markedly larger in kids with hemimegaly (52.8 ml/kg); 57 patients needed hemotransfusion during surgery. Median length of stay in ICU was 14.7 hours, and the length of stay in the hospital until discharge - 6.5 days. Eight patients underwent second-look surgery to complete sectioning of undercut commissural fibers. FU is known in 91 patients (med. length - 1.5 years). RESULTS: Major surgical complications with serious hemorrhage and/or surgery induced life-threatening events developed in 7 patients (one of them has died on the 5th day post-surgery for the causes of brain edema and uncontrolled hyponatremia). Various early and late infectious complications were noted in 4 cases. Ten patients experienced new not anticipated but temporary neurological deficit. Nine patients needed shunting for the causes of hydrocephalus within several first months post-hemispherotomy. Early seizure onset was associated with probability of all complications in general (p=0.02), and developmental etiology - with intraoperative bleeding and hemorrhagic complications (p=0.03). CONCLUSION: Children with developmental etiology, particularly those with hemimegalencephaly, are most challengeable in terms of perioperative hemorrhage and serious complications. Patients with relapse or persisting seizures should be evaluated for the possibility of incomplete hemispheric isolation and have good chances to become SF by re-doing hemispherotomy.

[Lessons learnt from 101 hemispherotomies in children with symptomatic epilepsy. Part I: seizure outcome]. / Uroki 101 gemisferotomii u detei s polusharnoi simptomaticheskoi epilepsiei. Chast' I. Iskhody lecheniya pristupov.

OBJECTIVE: To evaluate variables that may predict the outcome after hemispherotomy basing on a retrospective study of a large consecutive pediatric cohort of patients from a single institution. MATERIAL AND METHODS: One hundred and one patients with refractory seizures and variable decline in development (n=78) underwent hemispherotomy (med. age - 43 months, med. epilepsy history - 30 months). Developmental pathology was the anatomical substrate of disorder in 42 patients, while the infantile post-stroke scarring and gliosis was its origin in the majority of 43 cases with acquired etiology. The progressive pathology (the Rasmussen encephalitis, Sturge-Weber angiomatosis and tuberous sclerosis) was the etiology in 16 children. Left-sided hemisphere was impaired in 54 cases; some contralateral anatomical and potentially epileptogenic MRI-abnormalities were noted also in «healthy¼ hemisphere in » of all cases. Eight patients needed second surgery to complete sectioning of undercut commissural fibers. FU is known in 91 patients (med. - 1.5 years) and 73 of them were free of seizures (80.2%), but only 30 of 40 patients with FU > 2 years were still SF (75%). All but one of re-do hemispherotomies were successful. AED-treatment was discontinued in 46 cases and tapered in other 27 patients. Up to 90% of kids demonstrated some improvement in behavior and cognition. RESULTS AND CONCLUSION: Developmental pathology, infantile spasms and younger age onset of seizures are negative predictors for achievement of SF-status (p<0.05). Neither bilateral epileptic EEG-signs, nor MRI-abnormalities in «healthy¼ hemisphere had any relation to outcome, but focal seizure onset was associated positively with further SF-status (p = 0.03). Kids with multiple lobe unilateral CD do somewhat worse than their counterparts with hemimegalencephaly and acquired etiology. Post-hemispherotomy hemiparesis (either new or worsening of already existed one) has no relation either to the age at surgery, or to the age onset (p = 0.41). Children with left-sided lesions were less successful in every neurodevelopmental domain except maintaining expressive language. Patients with relapse or persisting seizures have good chances to become SF by re-doing hemispherotomy and should be evaluated for the possibly incomplete hemispheric isolation.

[Surgical treatment of drug-resistant epilepsy following hippocampal sclerosis]. / Khirurgicheskoe lechenie farmakorezistentnoi epilepsii pri skleroze gippokampa.

Surgery is an effective approach for drug-resistant temporal lobe epilepsy following hippocampal sclerosis. There is still no clear and unanimous opinion about advantages and disadvantages of certain surgical technique. MATERIAL AND METHODS: There were 103 surgical interventions in 101 patients. Females prevailed (1.45:1). Age of patients ranged from 16 to 56 years (median 28). Anteromedial temporal lobectomy and selective amygdaloghippocampectomy were performed in 49 (47.6%) and 54 (52.4%) patients, respectively. In the latter group, 30 patients were operated via a 14-mm burr hole-subtemporal approach. Postoperative outcomes were assessed using the Engel grading system. The follow-up period ranged from 2 to 8 years (median 4 years). RESULTS: By the 2nd year, Engel class I was observed in 74 (72%) patients, Engel II, III and IV - in 20 (19.4%), 6 (5.8%) and 3 (2.9%) patients, respectively. Engel class I was achieved after anteromedial temporal lobectomy in 68% of cases, selective amygdaloghippocampectomy via standard approaches in 75% of cases, amygdaloghippocampectomy via subtemporal burr hole approach - in 80% of cases. Neurocognitive impairments after anteromedial lobectomy and selective amygdaloghippocampectomy were similar. At the same time, mental disorders de novo prevailed in the group of anteromedial lobectomy (p<0.05). There were no severe visual field disorders after subtemporal burr-hole access. In other cases, these disorders occurred in 36.2% of patients (p<0.05). There were 8 (7.8%) postoperative complications: 5 (10.2%) - after anterior temporal lobectomy, 3 (5.5%) - after selective surgeries via standard approaches. There were no complications after burr-hole surgery. CONCLUSION: Selective amygdaloghippocampectomy is not inferior to anteromedial lobectomy. Moreover, this procedure is associated with a lower risk of complications and adverse events.

[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.

[Stereoelectroencephalography (seeg): a brief historical review of modern deep electrode implantation methods used for diagnosis and treatment of epilepsy]. / Stereoelektroentsefalografiya. Kratkii istoricheskii ocherk i obzor sovremennykh metodov implantatsii glubinnykh elektrodov, ispol'zuemykh dlya diagnostiki i lecheniya epilepsii.

More than 30% of patients with symptomatic epilepsy are resistant to drug therapy and therefore surgical treatment is the method of choice for such patients. Search and localization of the epileptogenic zone and all parts of the neural networks involved in stereotypic seizures are the most important objectives of pre-surgical evaluation and the prerequisite for the successful surgery. In the last decade, stereotactic implantation of multiple intracerebral multi-contact electrodes (SEEG) has been increasingly used for this purpose. The article includes a brief history of SEEG and a description of the major techniques for stereotactic implantation of electrodes. Information on accuracy (errors and deviations from planned target) and on complications are summarized. The data on the clinical value of the method and how these data affected the results of subsequent treatment are highlighted. The method of thermocoagulation and its results are briefly considered.

[Surgical treatment of epilepsy in children with focal cortical dysplasia]. / Khirurgicheskoe lechenie epilepsii u detei s fokal'noi kortikal'noi displaziei.

OBJECTIVE: Surgery is the first-line treatment option in children with FCD and refractory epilepsy, but the rate of success and patient numbers who became free of seizures vary widely from series to series. STUDY AIMS: To elicit variables affecting the outcome and predicting achievement of the long-term seizure-free status. MATERIAL AND METHODS: One hundred sixty-nine children with cortical dysplasia and DR-epilepsy underwent surgery Preoperative evaluation included prolonged video-EEG and MRI (in all patients) and neuropsychological testing when possible. Fourteen patients underwent invasive EEG, fMRI and MEG were used also in some cases. Including 27 repeat procedures the list of overall 196 surgeries performed consists of: cortectomy (lesionectomy with or without adjacent epileptogenic cortices) ­ in 116 cases; lobectomy ­ in 46; and various disconnective procedures ­ in 34 patients. Almost routinely employed intraoperative ECOG (134 surgeries) was combined with stimulation and/or SSEP in 47 cases to map eloquent cortex (with CST-tracking in some). A new permanent and not anticipated neurological deficit developed post-surgery in 5 cases (2,5%). Patients were follow-upped using video-EEG and MRI and FU which lasts more than 2 years (median ­ 3 years) is known in 56 cases. Thirty-two children were free of seizures at the last check (57,2% rate of Engel IA). A list of variables regarding patients' demography, seizure type, lesion pathology and localization, and those related to surgery and its extent were evaluated to figure out anyone associated with favorable outcome. RESULTS: Both Type II FCDs and their anatomically complete excision are positive predictors for favorable outcome and achievement of SF-status (p<0,05). Residual epileptic activity on immediate post-resection ECOG do not affect the outcome. CONCLUSION: Patients with Type II FCD, particularly with Type IIb malformations are the best candidates for curative surgery, including cases with lesions in brain eloquent areas. Kids with Type I FCD have much less chances to become free of seizures when attempting focal cortectomy. However, some of them with early onset catastrophic epilepsies may benefit from larger surgeries using lobectomy or various disconnections.

[Surgical treatment of epilepsy in children with gloneuronal brain tumors: morphology, MRI semiology and factors affecting the outcome]. / Khirurgicheskoe lechenie épilepsii u detei s glioneironal'nymi opukholiami mozga: morfologiia, magnitno-rezonansno-tomograficheskaia semiologiia i faktory, vliiaiushchie na iskhod.

INTRODUCTION: Glioneuronal tumors (GNT) are usually found in children (less than 1.5% of all neoplasms of the brain). With rare exceptions, they are benign and usually manifest only by epilepsy, which is quite often resistant to treatment with AE drugs. Tumor removal usually helps to cope with epileptic seizures, however, a number of issues regarding diagnosis and surgical treatment (interpretation of morphological data and classification, epileptogenesis and topography of the epileptogenic zone, the value of intraoperative invasive EEG and the optimal volume of resection) remain debatable. AIM: To describe the morphology, electro-clinical picture and MR-semiology in patients with gloneuronal brain tumors, as well as to analyse the results of their surgical treatment and the factors determining its outcome. MATERIAL AND METHODS: 152 children with a median age of 8 years were treated surgically (There were 64 gangliogliomas, 73 DNT, 15 cases where the tumor classification failed - GNT NOS). In children under 2 years of age, temporal localization of the tumor prevailed. In 81 cases, ECoG was used during the operation. Surgical treatment complications: transient neurological deficit (in 15 cases); hematomas removed without consequences (in 2 cases), infectious (osteomyelitis of bone bone flap in 2 cases). We analyzed: the age of the epilepsy onset (median - 4 years 7 months) and its duration (median - 23.5 months), the type of seizures, as well as the features of MR-semiology and morphology of tumors and adjacent areas of the brain. The volume of tumor resection was verified by MRI (in 101 cases) and CT (in each case). The follow-up was collected through face-to-face meetings, with repeated video EEG and MRI, as well as telephone interviews. We studied the effect of a number of parameters characterizing the patient and features of his/her operation on the outcome of treatmen. RESULTS: Among 102 patients in whom the follow-up history is one year or more (median - 2 years), a favorable outcome (Engel IA) was observed in 86 of them (84%); 55 of them (54%) at the time of the last examination stopped drug AE treatment. Radical tumor removal and younger age at the time of surgery were statistically significantly associated with a favorable result. CONCLUSION: In children with gloneuronal brain tumors, removal of the tumor is effective and relatively safe in the treatment of symptomatic epilepsy. Radical tumor resection and earlier intervention are the most important prerequisites for a favorable outcome and persistent remission of seizures.

[Application of intraoperative electromagnetic frameless navigation in transcranial and endoscopic neurosurgical interventions]. / Primenenie bezramnoi sistemy intraoperatsionnoi élektromagnitnoi navigatsii pri transkranial'nykh i éndoskopicheskikh neirokhirurgicheskikh vmeshatel'stvakh.

The paper summarizes the experience in using a system of electromagnetic intraoperative frameless navigation in various neurosurgical pathologies of the brain. The electromagnetic navigation technique was used for 102 operations in 98 patients, including 36 transnasal endoscopic interventions. There were no intraoprtative and postoperative complications associated with the use of the system. In the process of using the system, factors influencing the accuracy of navigation and requiring additional control by the surgeon were identified. PURPOSE: The study purpose was to evaluate the use of electromagnetic navigation in surgical treatment of patients with various brain lesions. MATERIAL AND METHODS: The system of electromagnetic navigation was used for 102 operations in 98 patients (42 males and 56 females, including 18 children; median age, 34.8 years (min, 2.2 years; max, 69 years)) in the period from December 2012 to December 2016. In 36 patients, the system was used for endoscopic interventions. In 19 patients, electromagnetic navigation was used in combination with neurophysiological monitoring. RESULTS: In our series of cases, the frameless electromagnetic navigation system was used in 66 transcranial operations. The mean error of navigation was 1.9±0.5 mm. In 5 cases, we used the data of preoperative functional MRI (fMRI) and tractography for navigation. At the same time, in all 7 operations with simultaneous direct stimulation of the cortex, there was interference and significant high-frequency noise, which distorted the electrophysiological data. A navigation error of more than 3 mm was associated with the use of neuroimaging data with an increment of more than 3 mm, image artifacts from the head locks, high rate of patient registration, inconsequence of touching points on the patient's head, and unsatisfactory fixation to the skin or subsequent displacement of a non-invasive localizer of the patient. In none of the cases, there was a significant effect of standard metal surgical tools (clamps, tweezers, aspirators) located near the patient's head on the navigation system. In two cases, the use of massive retractors located near the patient's localizer caused noise in the localizer and navigation errors of more than 10 mm due to significant distortions of the electromagnetic field. Thirty-six transnasal endoscopic interventions were performed using the electromagnetic frameless navigation system. The mean navigation error was 2.5±0.8 mm. CONCLUSION: In general, electromagnetic navigation is an accurate, safe, and effective technique that can be used in surgical treatment of patients with various brain lesions. The mean navigation error in our series of cases was 1.9±0.5 mm for transcranial surgery and 2.5±0.8 mm for endoscopic surgery. Electromagnetic navigation can be used for different, both transcranial and endoscopic, neurosurgical interventions. Electromagnetic navigation is most convenient for interventions that do not require fixation of the patient's head, in particular for CSF shunting procedures, drainage of various space-occupying lesions (cysts, hematomas, and abscesses), and optimization of the size and selection of options for craniotomy. In repeated interventions, disruption of the normal anatomical relationships and landmarks necessitates application of neuronavigation systems in almost mandatory manner. The use of electromagnetic navigation does not limit application of the entire range of necessary intraoperative neurophysiological examinations at appropriate surgical stages. Succession in application of neuronavigation should be used to get adequate test results.

[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.

[Supracerebellar transtentorial approach to tumors of the posterior portions of the medial temporal region].

OBJECTIVE: Despite the advances in microsurgery, the choice of the most adequate approach to the posterior part of the medial temporal region (MTR) remains a very controversial issue. The supracerebellar transtentorial approach (STA) is considered as the most preferable one, since it provides the optimal balance between retraction, incision, and resection of the brain tissue. Here, we present our consecutive series of 20 patients who underwent STA surgery. MATERIAL AND METHODS: Twenty patients with glial tumors affecting the posterior MTR underwent STA surgery between 2006 and 2014. The mean age of the patients was 20 years. Benign tumors were predominant (18 out of 20 cases). RESULTS: Resection of the posterior and middle MTRs was conducted in 16 cases. The anterior MTR was accessed through STA in 1 patient only; in 2 patients, STA was combined with the infraoccipital approach. Cerebellar edema occurred in 4 patients, with hemiparesis persisting in one of the cases for 1 year after surgery. Of 8 patients with drug resistant epilepsy, the Engel class 1 or 2 outcome was achieved in 6 cases within 1 year after surgery. CONCLUSION: STA provides an excellent surgical route to the posterior and middle MTR portions; however, the anterior MTR portions cannot be reached safely. The operative risks of STA increase as the surgeon proceeds with resection of the anterior MTR portions. Anterior MTR structures can be removed using a combination of the supracerebellar and infraoccipital transtentorial approaches or two-stage resection.