The Analysis of Electroencephalography Changes Before and After a Single Neurofeedback Alpha/Theta Training Session in University Students.

The underlying mechanisms of alpha/theta neurofeedback training have not been fully determined. Therefore, this study aimed to test the changes in the brain state feedback during the alpha/theta training. Twenty-seven healthy participants were trained during a single session of the alpha/theta protocol, and the resting quantitative electroencephalography (QEEG) was assessed before and after training. QEEG was recorded at eight scalp locations (F3, F4, C3, C4, T3, T4, O1, and O2), and the absolute power, relative power, ratio of sensory-motor rhythm beta (SMR) to theta (RST), ratio of SMR-mid beta to theta (RSMT), ratio of mid beta to theta (RMT), ratio of alpha to high beta (RAHB), and scaling exponent of detrended fluctuation analysis by each band were measured. The results indicated a significant increase of absolute alpha power, especially the slow alpha band, at all electrodes except T3 and T4. Moreover, the relative alpha power, especially the slow alpha band, showed a significant increase at all electrodes. The relative theta power showed a significant decrease at all electrodes, except T3. A significant decrease in relative beta power, relative lower beta power and relative mid beta power was observed at O1. RST (at C4, O1, and O2), RSMT and RMT (at F4, C4, O1 and O2), and RAHB (at all electrodes) showed significant increase. Scaling exponents at all electrodes except T3 showed a significant decrease. These findings indicate that a one-time session of alpha/theta training might have the possibility to enhance both vigilance and concentration, thus stabilizing the overall brain function.

Validation of a Paper and Pencil Test Battery for the Diagnosis of Minimal Hepatic Encephalopathy in Korea.

The aim of this study was to validate a new paper and pencil test battery to diagnose minimal hepatic encephalopathy (MHE) in Korea. A new paper and pencil test battery was composed of number connection test-A (NCT-A), number connection test-B (NCT-B), digit span test (DST), and symbol digit modality test (SDMT). The norm of the new test was based on 315 healthy individuals between the ages of 20 and 70 years old. Another 63 healthy subjects (n = 31) and cirrhosis patients (n = 32) were included as a validation cohort. All participants completed the new paper and pencil test, a critical flicker frequency (CFF) test and computerized cognitive function test (visual continuous performance test [CPT]). The scores on the NCT-A and NCT-B increased but those of DST and SDMT decreased according to age. Twelve of the cirrhotic patients (37.5%) were diagnosed with MHE based on the new paper and pencil test battery. The total score of the paper and pencil test battery showed good positive correlation with the CFF (r = 0.551, P < 0.001) and computerized cognitive function test. Also, this score was lower in patients with MHE compared to those without MHE (P < 0.001). Scores on the CFF (32.0 vs. 28.7 Hz, P = 0.028) and the computer base cognitive test decreased significantly in patients with MHE compared to those without MHE. Test-retest reliability was comparable. In conclusion, the new paper and pencil test battery including NCT-A, NCT-B, DST, and SDMT showed good correlation with neuropsychological tests. This new paper and pencil test battery could help to discriminate patients with impaired cognitive function in cirrhosis (registered at Clinical Research Information Service [CRIS], https://cris.nih.go.kr/cris, KCT0000955).

Characteristics of Cognitive Function Changes and Related Factors in Individuals With Cognitive Impairment During the Pandemic of COVID-19: A Retrospective Chart Review Study.

OBJECTIVE: This study aimed to explore the characteristics and factors related to changes in cognitive function in vulnerable individuals with cognitive impairment during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Among patients who visited a local university hospital with subjective cognitive complaints, those who had been tested for cognitive function at least once after the onset of COVID-19 and tested regularly at least three times within the last 5 years were included (1st, the initial screening; 2nd, the test immediately before the COVID-19 pandemic; 3rd, the most recent test after the pandemic). Finally, 108 patients were included in this study. They were divided into groups according to whether the Clinical Dementia Rating (CDR) was maintained/improved and deteriorated. We investigated the characteristics of the changes in cognitive function and related factors during COVID-19. RESULTS: When comparing CDR changes before and after COVID-19, there was no significant difference between the two groups (p=0.317). Alternatively, the main effect of the time when the test was conducted was significant (p<0.001). There was also a significant difference in the interaction between the groups and time. When the effect of the interaction was analyzed, the CDR score of the maintained/ improved group significantly decreased before COVID-19 (1st-2nd) (p=0.045). After COVID-19 (2nd-3rd), the CDR score of the deteriorated group was significantly higher than that of the maintained/improved group (p<0.001). Mini-Mental State Examination recall memory and changes in activity during COVID-19 were significantly associated with CDR deterioration. CONCLUSION: Memory dysfunction and decreased activity during the COVID-19 pandemic are strongly related to the deterioration of cognitive impairment.

A Study on Verification of Equivalence and Effectiveness of Non-Pharmacologic Dementia Prevention and Early Detection Contents : Non-Randomly Equivalent Design.

OBJECTIVE: The aim of this study was to verify the equivalence and effectiveness of the tablet-administered Korean Repeatable Battery for the Assessment of Neuropsychological Status (K-RBANS) for the prevention and early detection of dementia. METHODS: Data from 88 psychiatry and neurology patient samples were examined to evaluate the equivalence between tablet and paper administrations of the K-RBANS using a non-randomly equivalent group design. We calculated the prediction scores of the tablet-administered K-RBANS based on demographics and covariate-test scores for focal tests using norm samples and tested format effects. In addition, we compared the receiver operating characteristic curves to confirm the effectiveness of the K-RBANS for preventing and detecting dementia. RESULTS: In the analysis of raw scores, line orientation showed a significant difference (t=-2.94, p<0.001), and subtests showed small to large effect sizes (0.04-0.86) between paper- and tablet-administered K-RBANS. To investigate the format effect, we compared the predicted scaled scores of the tablet sample to the scaled scores of the norm sample. Consequently, a small effect size (d≤0.20) was observed in most of the subtests, except word list and story recall, which showed a medium effect size (d=0.21), while picture naming and subtests of delayed memory showed significant differences in the one-sample t-test. In addition, the area under the curve of the total scale index (TSI) (0.827; 95% confidence interval, 0.738-0.916) was higher than that of the five indices, ranging from 0.688 to 0.820. The sensitivity and specificity of TSI were 80% and 76%, respectively. CONCLUSION: The overall results of this study suggest that the tablet-administered K-RBANS showed significant equivalence to the norm sample, although some subtests showed format effects, and it may be used as a valid tool for the brief screening of patients with neuropsychological disorders in Korea.

The Korean Repeatable Battery for the Assessment of Neuropsychological Status-Update : Psychiatric and Neurosurgery Patient Sample Validity.

OBJECTIVE: This study aimed to validate the Korean version of the Repeatable Battery for the Assessment of Neuropsychological Status Update (K-RBANS). METHODS: We performed a retrospective analysis of 283 psychiatric and neurosurgery patients. To investigate the convergent validity of the K-RBANS, correlation analyses were performed for other intelligence and neuropsychological test results. Confirmatory factor analysis was used to test a series of alternative plausible models of the K-RBANS. To analyze the various capabilities of the K-RBANS, we compared the area under the receiver operating characteristic (ROC) curves (AUC). RESULTS: Significant correlations were observed, confirming the convergent validity of the K-RBANS among the Total Scale Index (TSI) and indices of the K-RBANS and indices of intelligence (r=0.47-0.81; p<0.001) and other neuropsychological tests at moderate and above significance (r=0.41-0.63; p<0.001). Additionally, the results testing the construct validity of the K-RBANS showed that the second-order factor structure model (model 2, similar to an original factor structure of RBANS), which includes a first-order factor comprising five index scores (immediate memory, visuospatial capacity, language, attention, delayed memory) and one higher-order factor (TSI), was statistically acceptable. The comparative fit index (CFI) (CFI, 0.949) values and the goodness of fit index (GFI) (GFI, 0.942) values higher than 0.90 indicated an excellent fit. The root mean squared error of approximation (RMSEA) (RMSEA, 0.082) was considered an acceptable fit. Additionally, the factor structure of model 2 was found to be better and more valid than the other model in χ2 values (Δχ2=7.69, p<0.05). In the ROC analysis, the AUCs of the TSI and five indices were 0.716-0.837, and the AUC of TSI (AUC, 0.837; 95% confidence interval, 0.760-0.896) was higher than the AUCs of the other indices. The sensitivity and specificity of TSI were 77.66% and 78.12%, respectively. CONCLUSION: The overall results of this study suggest that the K-RBANS may be used as a valid tool for the brief screening of neuropsychological patients in Korea.

Repetitive transcranial magnetic stimulation of the supplementary motor area in treatment-resistant obsessive-compulsive disorder: An open-label pilot study.

Obsessive-compulsive disorder (OCD) is a severely distressing disorder represented by obsessions and compulsions. A significant proportion of OCD patients fail to improve with conventional treatment methods. Repetitive transcranial magnetic stimulation (rTMS) has been proposed as an alternative for OCD treatment. Functional neuroimaging studies indicate that OCD is associated with increased activity in the supplementary motor area (SMA), a region that plays an important role in the pathophysiology of this disorder. In this study, we assessed the efficacy of augmentation with 1Hz rTMS over the SMA in treatment-resistant OCD patients. The participants received 1Hz rTMS over the SMA in 20 daily sessions for 4weeks. We observed significant reduction in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score at the 4th week of the treatment. Reduction in compulsion contributed to the reduction of global Y-BOCS whereas there was no significant reduction in obsession. Clinical global impression-global improvement also showed significant change at the 2nd and 4th week of the treatment. No additional significant changes or significant adverse effects were seen. These findings suggest that 1Hz rTMS over the SMA can be an efficient and safe add-on therapeutic method in treatment-resistant patients with OCD. Further controlled studies in larger samples are required to confirm the effect of 1Hz rTMS over the SMA in OCD.