[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.

[Surgery of posterior cranial fossa tumors in children in the prone position. The surgical technique features]. / Khirurgiia opukholei zadnei cherepnoi iamki u detei v polozhenii 'lezha na zhivote'. Osobennosti khirurgicheskoi tekhniki.

Posterior cranial fossa tumors are the most common neuro-oncological pathology of childhood. More than half of them are located along the midline, occupying the cerebellar vermis and 4th ventricle cavity. Historically, most of these tumors were operated on with the patient in sitting position. This tendency has significantly changed in the last 30 years. For example, 95% of all operations in Japan are now performed with the patient in lying position; for the US and Europe, these figures are 80 and 60%, respectively. This global tendency of switching to the lying position is mainly associated with a high risk of venous air embolism in the sitting position. In the period between 1999 and 2013, the first author used only the sitting position for resection of PCF tumors. During this period, he performed 606 operations. In patients with large/giant tumors (usually, these were piloid astrocytomas with cysts), the surgeon often faced the problem of excessive retraction of the cerebellum and rupture of the bridging veins, sometimes outside the surgical approach area. This situation led either to massive blood loss or to venous air embolism. MATERIAL AND METHODS: Therefore, beginning at 2013, we started to selectively use the prone position in cases of hemispheric piloid astrocytomas of the cerebellum. This initial experience allowed us to assess the surgical features of the procedure and use the experience in more complex interventions. Since the middle of 2016, given the tendency of using key-hole approaches, we have increasingly used the prone position in surgery of PCF tumors, sometimes removing tumors even through the burr hole. Since the end of 2016, we have routinely used the prone position for various tumors of the 4th ventricle. Between November 2016 and September 2017, the first author performed 113 surgeries for PCF tumors in children; of these, only 4 operations were performed in the sitting position. Thus, in less than a year, the prone position has become the main one in surgery for all PCF tumors in our practice. In this article, we would like to share our practical suggestions both about using the prone position and about its advantages and disadvantages that should be considered by a doctor who does not have experience of PCF surgery with the patient in prone position.

[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.

[Treatment of occupational neurosensory deafness and noises in internal ear].

Neurosensory deafness treatment can be effective only after removal of specific etiologic factor--exposure toindustrial noise, that necessitates change of work and occupation, i.e. occupational disablement. Search for effective, complex methods to treat and prevent neurosensory deafness in patients exposed to occupational noise remains topical problem in otorhinolaryngology and occupational therapy. The article presents a method of treatment and prevention of neurosensory deafness in patients exposed to occupational noise; demonstrates its efficiency. Combination of medical therapy and physical therapy improves function of conductive pathways of hearing analyser, enables adequate rehabilitation of hearing in workers--that was confirmed by audiologic and neurofunctional parameters. The method is inexpensive, can be operative in medical stations at enterprises.

[Blood loss in surgery of brain tumors in infants].

Functional immaturity of all organs and systems result in a high risk of complications in surgery of brain tumors in infants. One of the most serious complications is a massive blood loss and developing on its background severe disorders of hemostasis. In modern series of observations perioperative mortality in these children varies from 13 to 33%. The purpose of this paper--based on an analysis of topography, morphology and features of the operations to determine risk groups of blood loss in surgery of brain tumors in infants and suggest the best options for surgical tactics. When operating blood loss exceed 300% of the calculated blood volume persistent violations of coagulation homeostasis develop, which can lead to uncontrolled bleeding and death on the operating table, or post-operative bleeding. Intraoperative blood loss could be reduced by surgical techniques improvement, as well as by improving of anesthesia. First type includes preoperative embolization of the afferent vessels, careful planning of surgical approach, including using neuronavigation, deep stromal tumor coagulation during debulking, primary coagulation of main feeding blood vessels, two-stage surgery, and optimization of speed of tumor removal. All these methods has reduced the overall operational and post-operative mortality rate from 13 to 5%.

[Stereotactic radiotherapy and radiosurgery in treatment of patients with deep-seated pilocytic astrocytomas].

Pilocytic astrocytoma (PA) is a low-grade glial tumor (WHO grade I) with predominant occurrence in pediatric patients. According to many authors, stereotactic radiosurgery (SRS) and radiotherapy (SRT) promote long-term remission or retardation of tumor progression in patients with in inoperable lesions after incomplete resection or recurrence. Therefore it is essential to determine the role of SRS and SRT in complex management of patients with deep-seated PA. Since April 2005 till May 2010 101 patient with intracranial PA was treated in department for radiation therapy of Burdenko Neurosurgical Institute. The series consisted of 70 pediatric patients (below 17 years inclusively) and 31 adults, of them--51 male and 50 female patients. Mean age was 15.1 years (9.8 years in children and 28.7 in adults). In 90 patients (89.2%) tumors were previously histologically verified (tumor resection in 83 cases and biopsy in 7). In 11 (10.8%) patients diagnosis of PA was based on clinical and neurovisualization data. In most cases SRT (66 (66.3%) patients) was preformed, the rest 35 (34.7%) patients were treated by SRS. Median follow-up from the onset of disease reached 52 months (2-228 months). Catamnestic data were available in 88 (87%) patients. By the end of catamnestic follow-up (December 2010) 87 (98.8%) patients treated by SRS and SRT were alive. Median follow-up from the start of radiation treatment was 22.7 months (6-60 months). Progression of tumor was observed in 20 patients (22.7%), in 18 of them due to cyst growth. 18 patients were reoperated. In 12 operated patients histological examination and its comparative analysis were performed. We found that alterations in the tumor tissue, accompanied by regression of solid component and progression of cystic portion, represent reactive-degenerative changes in the tumor as a consequence of radiation-induced pathomorphism. SRS and STR are effective techniques for treatment of patients with primary and recurrent PA despite regardless of localization of the tumor. There procedures should be performed shortly after non-radical resection. Control of tumor growth by the present time (median follow-up is 22.7 months) reaches 98%. "Progression" of the tumor due to enlargement of cystic portion shortly after SRT and SRS represents reactive-degenerative alterations in the tumor tissue and should not be evaluated as true recurrence; without neurological deterioration these cases do not require special treatment.

[Application of SPECT/CT in neurosurgical practice].

The paper presents the experience of application of single-photon emission computed tomography (SPECT) and CT in neurosurgery. Combination of these two techniques in the single system provides higher precision of both methods. The novel technique allows assessment of tumor spread in the brain, differential diagnosis of tumor regrowth and radiation-induced necrosis, evaluation of cerebral perfusion in epilepsy, traumatic brain injury (TBI), and diagnostics of secondary CNS lesions. Examples of primary diagnosis, dynamic follow-up and differential diagnosis of cerebral neoplasms, localization of epileptogenic foci in planning of surgery, prediction of outcome after TBI and evaluation of spread of metastatic skeletal involvement and further application of acquire data are presented.

[Oral premedication with midasolam and ketamine in children with neurosurgical diseases].

The study was undertaken to evaluate the efficiency and safety of oral premedication in children with intracranial neurosurgical pathology before elective interventions in two modalities: a combination of midasolam 0.5 mg/kg body weight and ketamine 3 mg/kg (Group 1; n = 80) and midasolam 0.75 mg/kg only (Group 2; n = 20). The study was conducted in 100 children aged 2 to 10 years. Medical and sweet syrups were used to dilute the agents. In Groups 1 and 2, an effective anxiolytic effect was achieved in 92 and 80%, respectively. A sedative effect was also more pronounced in Group 1 children. The mean duration of effect achievement was 20 minutes. There were no serious complications when both regimens were used. Both oral premedication modes are considered to be effective and must be used for premedication in children with neurosurgical diseases.

[Blood-sparing techniques in pediatric neuroanesthesiology].

The paper analyzes the clinical effectiveness of various blood-sparing techniques (hypervolemic hemodilution, isovolemic hemodilution, and instrumental infusion of washed autoerythrocytes) in neurosurgical interventions (n = 93) in 89 patients. Hypervolemic hemodilution that remains, however, to be the method of choice for young and low-weight children has proved to be the least clinically effective as a method for blood saving. The blood-sparing effectiveness of isovolmic hemodilution and instrumental reinfusion of washed autoerythrocytes is about the same, but the efficiency of reinfusion was higher with a blood loss volume of more than 100% of the proper volume of circulating complexes. A combination of hemodilution and instrumental reinfusion of autoerythrocytes provides a summation of blood-sparing effects for the mechanisms of blood saving vary with these techniques. The use of any blood-sparing technique accelerates and worsens hemostatic disorders.

[Dislocation and impaction of the brain after purgetive enema]. / Dislokatsiia i vklinenie mozga posle ochistitel'noi klizmy.

The paper describes a case of dislocation and impaction of the brain in a child with a large brain tumor, which developed after purgetive enema. It also discusses the management of patients with this complication and possible ways of its prevention.

[Gas embolism caused by erroneous intraventricular administration of hydrogen peroxide solution]. / Gazovaia émboliia vsledstvie oshibochnogo intraventrikuliarnogo vvedeniia rastvora perekisi vodoroda.

An extremely rare case is described: massive gas (oxygen) embolism resultant from erroneous intraventricular administration of 3% hydrogen peroxide solution, which manifested by total systems hemodynamic and respiratory disorders. Hydrogen peroxide, which is still widely used in surgery, is a serious risk factor as regards gas embolism.