Background. Neuronal and mixed neuronal-glial tumors are rare brain tumors that are most commonly observed in pediatric patients. The main clinical manifestations are presented by epilepsy substantially affecting child’s physical and neurocognitive development.Objective: to assess short-term and long-term changes in seizure frequency and neurocognitive status in pediatric patients who underwent surgery for mixed neuronal-glial tumors.Material and methods. Thirty-eight pediatric patients underwent surgery for mixed neuronal-glial tumors at the Almazov Research Medical Centre within the period from 2008 to 2018. All patients had comprehensive diagnostic examination including clinical neurological examination, neuroimaging tests, electroencephalography and electrocorticography before and after surgery. The postoperative changes in the seizures rate were assessed by using the 1993, 1996 Engel classification. Neurocognitive status was evaluated using The Child Behavior Checklist (a component of the Achenbach System of Empirically Based Assessment).Results. During the postoperative period, 84% of patients were found to be seizure-free; 42.6% demonstrated no clinically relevant behavioral disturbances or social adaption issues after the surgery. However, 76% of children experienced poor concentration. In a long-term perspective, seizures reoccured in 25% of patients and were not associated with any magnetic resonance signs of tumor progression.Conclusion. A gross total resection of the brain tumor was the main factor that affected changes over time in seizure rate. Assessment of long-term changes over time has shown that the patients tended to retain concentration difficulties, which should be taken into account while planning school education programs.

The aim of the research was to study changes in clinical and neuropsychological deficits in children with neoplasms of the chiasmal-sellar region (CSR) operated on via transcranial and endoscopic transsphenoidal approaches. The analysis of clinical and neuropsychological examination and surgical treatment of 24 children with CSR tumors was carried out. Two leading neuropsychological symptom complexes in children with CSR neoplasms were identified. Changes in neuropsychological parameters in children with CSR neoplasms during the studied observation period do not directly depend on the volume of the tumor. In the early postoperative period, timely correction of the identified fluid and electrolyte disorders is necessary for better recovery of the patient’s neuropsychological deficit. The preservation of cognitive functions in children after the removal of a CSR neoplasm is influenced not so much by the volume of the tumor or surgical access, as by the gentle technique of the operation.

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PURPOSE: Cerebellar mutism syndrome (CMS) is a common complication of posterior fossa surgery in children. We have compared the neuropsychological, emotional and behavioral profiles in children before and after removal of the posterior fossa tumor. METHODS: We performed clinical neuropsycological examination of 91 patients (47.2% boys, 52.8% girls) aged 4 -17, who were undergoing primary surgical treatment of tumors of cerebellum, brain stem and 4 th ventricle. The patients were classified into 3 groups according to the severity of postoperative neuropsychological defect: Group 1 -with CMS., Group 2 -with cerebellar cognitive affective syndrome without speech loss (CCAS), Group 3 -no complex neuropsychological symptoms and signs. We used neuropsychological scales for children of different age groups by E.G. Simernitskaya, A.V. Semenovich; Yale-Brown obsessive compulsive scale, Aichenbach child behavior checklist, Zakharov neurotization scale. RESULTS: Children in CMS group (25.3%) before surgery showed significant difference from other groups on the following factors of neurotization and obsessive-compulsive disorder, dysprosody, impaired visual memory, decreased dynamics, becoming exhausted, and dyssomnia (p , 0/05). Significant risk factors for CMS included midline and paramedian localization of tumor, high-grade (III-IV), marked hydrocephalus. The neuropsychological status in the CCAS Group (20.9%) was intact, and the patients had high neurotization level with obsessive compulsive traits and dyssomnia (insomnia). These symptoms and signs tended to progress following surgery in the form of psychomotor agitation with pathopsychological and psychosensorial elements. Children in Group 3 (53.8%) had moderate emotional lability, decreased dynamics, impaired praxis and visual-motor coordination which tended to regress after the process had been eliminated. CONCLUSION: The revealed neuropsychological symptom complex of irritation of the brain stem and the limbic system, as well as of insufficiency of postfrontal and secondary parietal-temporal-occipital areas of the cortex in children with median anaplastic Posterior Fossa Tumor might be indicative of the disturbance of the dento-thalamo-cortical pathways and be a significant risk factor for developing CMS.