The Role of the Cerebellum in Visual-Spatial Memory in Pediatric Posterior Fossa Tumor Survivors.

The cerebellum is involved in motor and non-motor functions. Cerebellar lesions can underlie the disruption of various executive functions. The violation of executive functions in cerebellar lesions is a serious problem, since children, after completing treatment, must return to school, finish their education, and get a profession. One of the important executive functions is working memory, which contributes to academic success. Deficits of verbal working memory in cerebellar tumors have been studied, in contrast to visual-spatial working memory. To assess this issue, 101 patients who survived cerebellar tumors and 100 healthy control subjects performed a visual-spatial working memory test. As a result, in children who survived cerebellar tumors, visual-spatial working memory is impaired compared to the control group. Moreover, with age, and hence the time since the end of treatment, the number of elements that children can retain in visual-spatial working memory increases, but still remains smaller compared to the control group. Our findings complement the idea of cerebellar involvement in visual-spatial working memory and suggest that it is disrupted by cerebellar lesions in children.

Effects of cognitive-motor intervention for pediatric posterior fossa tumor survivors: results of a pilot study.

The purpose of this prospective pilot study was to evaluate the feasibility and effects of cognitive-motor intervention on the cognitive and motor abilities of pediatric survivors of posterior fossa tumors. The study involved patients aged 7 to 18 years with cognitive deficits who had completed primary treatment for posterior fossa tumors. 25 participants (Mage=11.3 ± 2.93, 64% male; 17 medulloblastoma, 1 ependymoma, 1 desmoplastic medulloblastoma, 6 piloid astrocytoma; 22 in remission (Mmonths =45), 3 in stabilization (Mmonths=49)) were recruited from the Research Institute for Brain Development and Peak Performance. The intervention consisted of two phases with a 3-month break for home training, and a total duration of 6 months. Each phase lasted 7 weeks and included two assessment procedures (pre- and post-intervention) and 10 training sessions over a period of 5 weeks (two 3-hour sessions per week). At baseline and pre- and post-intervention, all participants underwent a battery of cognitive and motor tests. Each training session included gross motor training (GMT), graphomotor training (GT), and cognitive-motor training (CMT). Statistical analysis was performed using the Friedman test for repeated measures and post-hoc Durbin-Conover test. The results indicated significant improvements in visuospatial working memory, visual attention, eye-hand coordination, semantic verbal fluency, auditory-motor synchronization, reaction time, and a decrease in the rate of ataxia. These improvements remained stable even in the absence of direct intervention. The findings demonstrate positive effects and feasibility of the intervention and suggest the need for further research in this area including randomized controlled feasibility studies with a larger sample.

Phonological Verbal Fluency Test for Russian-Speaking Children.

INTRODUCTION: Verbal fluency tasks are mainly used for assessment of verbal fluency and have proven useful for differential diagnosis. The first objective of the study was to provide normative data on phonemic verbal fluency (for letters "Π" [p], "O" [o], "C" [s]) in children population. The second objective of the study was to establish diagnostic validity of the present task and to collect normative data on participants who survived posterior fossa tumor (PFT) and participants with treated hemoblastosis. METHOD: For diagnostics, we used verbal fluency test. The normative sample consisted of 746 participants aged 7-16 years. A linear multiple regression analysis was implemented for each dependent variable with age, gender, disease for all participants and academic achievement as predictors in normative sample. The performance of 746 healthy participants was compared to the performance of 118 participants who survived PFT and 492 participants who survived hemoblastosis using one-way ANOVA analysis. RESULTS: Healthy children have better verbal fluency than their peers who survived cancer. In the group of healthy children, we assessed the relationship between verbal fluency and school performance. A significant correlation with the "Russian language" subject (r = 0.127; p < 0.001) emerged. In all three groups of children, age and gender turned out to be significant factors that affected the characteristics of verbal fluency. CONCLUSION: Our data will contribute to increasing the accuracy of verbal fluency deficit detection in Russian speakers and will be useful for differential diagnosis of cognitive impairment for children who have survived oncological diseases of various geneses.

Attention and memory after COVID-19 as measured by neuropsychological tests: Systematic review and meta-analysis.

COVID-19 is associated with a range of sequelae, including cognitive dysfunctions as long-standing symptoms. Considering that the number of people infected worldwide keeps growing, it is important to understand specific domains of impairments to further organize appropriate rehabilitation procedures. In this study we conducted a meta-analysis to investigate specific cognitive functions impacted by COVID-19. A literature search was conducted in Web of Science, Scopus, PubMed, Academic Search Premier, Health Source: Nursing/Academic Edition, and preprint databases (OSF and PsyArXiv via OSF Preprints, medRxiv, bioRxiv, Research Square). We included the studies that compared cognitive functioning in COVID-19 reconvalescents and healthy controls, and used at least one validated neuropsychological test. Our findings show that short-term memory in the verbal domain, and possibly, visual short-term memory and attention, are at risk in COVID-19 reconvalescents. The impact of COVID-19 on cognitive functioning has yet to be studied in detail. In the future more controlled studies with validated computerized tests might help deepen our understanding of the issue. PSYCINFO CLASSIFICATION: 3360 Health Psychology & Medicine.

Systematic Review and Meta-Analysis of Clinically Relevant Executive Functions Tests Performance after COVID-19.

It is widely known that COVID-19 has a number of prolonged effects on general health, wellbeing, and cognitive functioning. However, studies using differentiated performance measures of cognitive functions are still not widely spread making it hard to assess the exact functions that get impaired. Taking into account the similarities between post-COVID 'brain fog' and chemofog, we hypothesized that executive functions (EF) would be impaired. Literature search yielded six studies with 14 effect sizes of interest; pooled effect size was small to medium (d = -0.35). Combined with a narrative synthesis of six studies without a comparison group, these results show that EF get impaired after COVID-19; although, in most cases the impairment is transient and does not seem to be severe. These results specify the picture of 'brain fog' and may help to discover its mechanisms and ways of helping people with long COVID.

The feasibility and efficacy of short-term visual-motor training in pediatric posterior fossa tumor survivors.

BACKGROUND: Pediatric posterior fossa tumor (PFT) survivors experience a range of cognitive and motor impairments that require timely rehabilitation of these functions. In Russia, rehabilitation services are only just beginning to be formed; therefore, it is necessary to test rehabilitation protocols for children surviving cancer. AIM: To evaluate the efficacy of short-term cognitive and motor training (CMT) aimed on visual-motor integration in PFT survivors using training devices. DESIGN: "Single center" quasi randomized controlled experiment. SETTING: Outpatients of the Russkoe Pole Rehabilitation Center. POPULATION: The 63 children cancer survivors between the ages of 6 and 17 years. METHODS: The baseline level of cognitive and motor functions was assessed in all participants. Then the sample of patients split into two subgroups of equal sex, age, and diagnosis. The intervention subgroup received six sessions of CMT for two weeks, and the other subgroup underwent 'empty' two weeks with no intervention. Reassessment of motor and cognitive functions was conducted in all participants. Then the subgroups changed: the first subgroup underwent 'empty' two weeks, and the second subgroup completed the CMT, and further reassessment was provided. RESULTS: The primary results demonstrate an increase in gross and fine motor skills, motor coordination, visual-motor integration, and visual processing after CMT. Secondary results show that the age at onset is an important factor in the subsequent decline in cognitive, motor functions, and eye movements. Children with medulloblastoma perform worse on motor tests than children with astrocytoma. A tumor in the IV ventricle is the most harmful, and a tumor in the cerebellar hemispheres is the least harmful to a child's cognitive and motor development. CONCLUSIONS: This study shows the effectiveness of a short-term CMT program for children who survived PFT. The study also found that cognitive, motor, and visual-motor functions are affected by the tumor's localization, malignancy, and the child's age at onset. CLINICAL REHABILITATION IMPACT: Short-term rehabilitation methods can be useful in pediatric oncological practice. Reconstruction of cognitive functions can occur during the training of more "simple" functions, such as hand-eye integration. The study makes a significant contribution to the methods of short-term rehabilitation in children who survived cancer.

The Impact of Mild COVID-19 on Executive Functioning and Mental Health Outcomes in Young Adults.

COVID-19 is associated with a range of long-lasting symptoms related to cognitive and psycho-emotional spheres. Even mild cases of the disease can lead to persistent cognitive deficits and deterioration of the psycho-emotional state. The purpose of our study was to examine the presence and frequency of psycho-emotional disorders and cognitive deficits in students who recovered from mild form of COVID-19. A total of 40 COVID-19 survivors and 25 healthy controls participated in our study. We assessed three core cognitive functions (inhibition, working memory, task-switching), reaction time and motor speed. We also assessed depression, anxiety and fatigue with self-report questionnaires. The COVID-19 group manifested increased depression and decreased inhibition in comparison with the controls. Our results show that even in young adults who have recovered from mild COVID-19, there are persisting cognitive and psycho-emotional deficits.

Comparison of Neurocognitive Functioning and Fine Motor Skills in Pediatric Cancer Survivors and Healthy Children.

Background: The late treatment outcomes of pediatric brain tumors and of hematopoietic and lymphoid tissue tumors are an important focus of both rehabilitation and research. Neurocognitive and motor disorders induce further learning problems impeding social-emotional adaptation throughout a whole lifespan. Core deficits in short-term and working memory, visuospatial constructional ability, verbal fluency, and fine motor skills underlie distorted intellectual and academic achievement. This study aimed to assess the individual differences in cognitive ability and fine motor skills of pediatric tumor survivors and the age-matched healthy controls. Methods: A total of 504 tumor survivors after treatment and 646 age-matched healthy controls underwent neurocognitive and fine motor assessments. Findings: The group of tumor survivors scored significantly worse in both neurocognitive and fine motor skill in compared with the healthy control group. The pediatric brain tumor survivors (PBT group) performed worse in cognitive (p < 0.001 for verbal fluency and p < 0.001 for visuospatial constructional ability) and motor tests (p < 0.001) compared to the healthy controls. Hematopoietic and Lymphoid Tissues tumors survivors (THL group) performed worse in verbal fluency (p < 0.01) and visuospatial constructional test (p < 0.001) compared to the control group. Furthermore, the PBT group had worse results in visuospatial constructional ability (p < 0.05) and fine motor (p < 0.001) ability than the THL group. Significant differences between females and males were found in fine motor test performance in the PBT group (p < 0.05), as well as in verbal fluency (p < 0.01) and visuospatial constructional ability (p < 0.01) in the control group. Neurocognitive and fine motor skill characteristics in the THL group did not correlate with age.

The Validity and Reliability of the Turkish Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 7-18 in Russia.

Background: Fatigue is the most common complaint by children both during and after cancer treatment, but in Russia, there is no reliable method for assessing fatigue. Objective: To develop a Russian version of the Turkish Scale for the Assessment of Fatigue in Pediatric Oncology Patients Ages 7-18. Design: Our first step was to translate all the items of the Turkish questionnaire into Russian. Then, through discussion, we created a single proposition for each item. The next step was obtaining expert opinions to assess the validity. Once the expert estimates agreed, a pilot version of the questionnaire was formed. The next step was to collect a large sample of patients to study the reliability and validity of the questionnaire. Results: As a result of factor analysis, three factors were identified. The first factor was "fatigue associated with actions;" the second was "fatigue as feeling;" and the third was "fatigue associated with sleep difficulties." The children's and parents' versions had the same factor structure. Conclusions: This study showed the possibility of using the questionnaire in a Russian sample. That's why it is necessary to continue collecting and analyzing data in this direction. The reliability of the test was also assessed. The reliability of the parent version scored a Cronbach's alpha of 0.91. The reliability of the children's version showed a Cronbach's alpha of 0.93.

Magnetic resonance imaging of changes in the brain of children cured of acute lymphoblastic leukemia.

This study was aimed to systematize magnetic resonance imaging (MRI) presentation of toxic leukoencephalopathy, to find the correlation between method of central nervous system (CNS) leukemia prevention and changes on MRI, to find relationship between existence leukoencephalopathy on imaging and neurocognitive deficits in pediatric patients after anti-leukemic therapy. Brain MRI data of 48 children, who underwent a therapy course according to the ALL-MB intermediate risk protocol, was evaluated. In accordance with two arms of this protocol, they received either radiation therapy, or additional intrathecal administration of chemotherapeutic agents as a prevention of CNS leukemia. Also, neurocognitive tests were performed. According to the results of the performed investigation, 10 (50%) out of 20 children, who received cranial irradiation and 18 (66.6%) out of 27 patients, who received only intrathecal therapy demonstrated abnormal brain changes (leukoencephalopathy) according to MRI data. Leukoencephalopathy was mostly presented by diffuse zones and localized predominantly in the frontal and temporal lobes. There was no correlation between method of CNS prevention and the existence of leukoencephalopathy on MRI. The analysis of our data did not show significant differences in brain damage and severity of cognitive impairment depending on the type of prevention of CNS leukemia. Moreover, in this study no statistical correlation was found between leukoencephalopathy on MRI and neurocognitive impairment according to clinical tests data. Further long-term prospective studies and examinations should be performed to assess late neurotoxic effects.

Insulin receptor in the brain: Mechanisms of activation and the role in the CNS pathology and treatment.

While the insulin receptor (IR) was found in the CNS decades ago, the brain was long considered to be an insulin-insensitive organ. This view is currently revisited, given emerging evidence of critical roles of IR-mediated signaling in development, neuroprotection, metabolism, and plasticity in the brain. These diverse cellular and physiological IR activities are distinct from metabolic IR functions in peripheral tissues, thus highlighting region specificity of IR properties. This particularly concerns the fact that two IR isoforms, A and B, are predominantly expressed in either the brain or peripheral tissues, respectively, and neurons express exclusively IR-A. Intriguingly, in comparison with IR-B, IR-A displays high binding affinity and is also activated by low concentrations of insulin-like growth factor-2 (IGF-2), a regulator of neuronal plasticity, whose dysregulation is associated with neuropathologic processes. Deficiencies in IR activation, insulin availability, and downstream IR-related mechanisms may result in aberrant IR-mediated functions and, subsequently, a broad range of brain disorders, including neurodevelopmental syndromes, neoplasms, neurodegenerative conditions, and depression. Here, we discuss findings on the brain-specific features of IR-mediated signaling with focus on mechanisms of primary receptor activation and their roles in the neuropathology. We aimed to uncover the remaining gaps in current knowledge on IR physiology and highlight new therapies targeting IR, such as IR sensitizers.