Association of EEG and cognitive impairment in overweight and non-overweight patients with schizophrenia.

OBJECTIVE: Schizophrenia (SCZ) is a globally prevalent, severe chronic mental disorder, with cognitive dysfunction being one of its core symptoms. Notably, overweight is exceedingly common among individuals with SCZ, and overweight can also impact cognitive function. Therefore, the relationship between overweight and cognition in SCZ is a clinical issue that is in need of research attention. METHODS: This study enrolled 77 patients with SCZ, including 36 overweight and 41 non-overweight patients. The Positive and Negative Syndrome Scale (PANSS) was used to assess symptom severity, while cognitive functions were evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Electroencephalography (EEG) testing was performed, with power spectral analysis conducted across various frequency bands (δ, θ, α, ß, low γ, and high γ). RESULTS: Compared to non-overweight SCZ patients, those overweight exhibited significantly lower RBANS total and index scores in immediate memory, visuospatial/constructional abilities, and delayed memory. EEG spectral analysis revealed that overweight SCZ patients demonstrated significantly lower oscillation power ratios in the ß, low γ, and high γ frequency bands compared to their non-overweight counterparts. Correlation analyses indicated a significant positive relationship between ß wave activity and RBANS total scores among overweight SCZ patients, suggesting that reduced ß power correlates with more severe cognitive dysfunction. CONCLUSION: Our findings indicate that overweight SCZ patients experience more severe cognitive impairments in a resting state than those who are not overweight, with significant differences in EEG spectrum observed in the ß and γ frequency bands. Additionally, our study establishes a correlation between various EEG spectrum dimensions and cognition. This research highlights the effects of overweight on cognition in individuals with SCZ. Additionally, employing EEG technology to study cognitive function in overweight SCZ patients can offer valuable electrophysiological insights.

Cognitive enhancing effect of rTMS combined with tDCS in patients with major depressive disorder: a double-blind, randomized, sham-controlled study.

BACKGROUND: Cognitive dysfunction is one of the common symptoms in patients with major depressive disorder (MDD). Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been studied separately in the treatment of cognitive dysfunction in MDD patients. We aimed to investigate the effectiveness and safety of rTMS combined with tDCS as a new therapy to improve neurocognitive impairment in MDD patients. METHODS: In this brief 2-week, double-blind, randomized, and sham-controlled trial, a total of 550 patients were screened, and 240 MDD inpatients were randomized into four groups (active rTMS + active tDCS, active rTMS + sham tDCS, sham rTMS + active tDCS, sham rTMS + sham tDCS). Finally, 203 patients completed the study and received 10 treatment sessions over a 2-week period. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was performed to assess patients' cognitive function at baseline and week 2. Also, we applied the 24-item Hamilton Depression Rating Scale (HDRS-24) to assess patients' depressive symptoms at baseline and week 2. RESULTS: After 10 sessions of treatment, the rTMS combined with the tDCS group showed more significant improvements in the RBANS total score, immediate memory, and visuospatial/constructional index score (all p < 0.05). Moreover, post hoc tests revealed a significant increase in the RBANS total score and Visuospatial/Constructional in the combined treatment group compared to the other three groups but in the immediate memory, the combined treatment group only showed a better improvement than the sham group. The results also showed the RBANS total score increased significantly higher in the active rTMS group compared with the sham group. However, rTMS or tDCS alone was not superior to the sham group in terms of other cognitive performance. In addition, the rTMS combined with the tDCS group showed a greater reduction in HDRS-24 total score and a better depression response rate than the other three groups. CONCLUSIONS: rTMS combined with tDCS treatment is more effective than any single intervention in treating cognitive dysfunction and depressive symptoms in MDD patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100052122).

The abnormal brain activation pattern of adolescents with major depressive disorder based on working memory tasks: A fNIRS study.

OBJECTIVE: Although studies have confirmed that working memory (WM) is impaired among adults with major depressive disorder (MDD), generalizing these neurocognitive impairments to adolescents with MDD would be tenuous. Therefore, separate studies for adolescents with MDD are needed. Relatively little is known about the neural processes associated with WM dysfunction in adolescents with MDD. Thus, we examined whether adolescents with MDD have abnormal brain activation patterns compared to healthy controls (HC) during WM tasks and whether it was possible to distinguish adolescents with MDD and HC based on mean oxy-hemoglobin (Oxy-Hb) changes. METHOD: A total of 87 adolescents with MDD and 63 HC were recruited. Functional near-infrared spectroscopy (fNIRS) was performed to monitor the concentrations of Oxy-Hb in the frontotemporal lobe while participants performed three WM tasks in order to examine WM impairments in adolescents with depression. RESULTS: The mean changes in Oxy-Hb concentrations in the left prefrontal cortex and right prefrontal cortex were higher among HC than among patients during the encoding and maintenance phase under each WM-load task. Machine learning was used to distinguish adolescents with MDD and HC based on Oxy-Hb changes, with a moderate area under the curve of 0.84. CONCLUSIONS: This study revealed WM defects in adolescents with MDD compared to HC based on mean Oxy-Hb changes, which can be valuable for distinguishing adolescents with MDD from HC.

Impact of twice-a-day transcranial direct current stimulation intervention on cognitive function and motor cortex plasticity in patients with Alzheimer's disease.

Background: Non-invasive brain stimulation has improved cognitive functions in patients with Alzheimer's disease (AD), and some studies suggest a close relationship between cognition and plasticity. However, the clinical benefits of transcranial direct current stimulation (tDCS) in patients still need to be evaluated. Aims: This study examined the role of tDCS in improving cognition and whether the improved cognition is related to altered cortical plasticity. Methods: 124 patients with AD were randomly assigned to active tDCS (n=63) or sham tDCS (n=61). The tDCS was applied at the dorsolateral prefrontal cortex for 30 treatment sessions across 6 weeks (5 days per week, 2 days off). The Mini-Mental State Examination and the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) were used for cognition evaluation at baseline, week 2 and week 6. The cortical plasticity was represented by motor-evoked potential (MEP) measured with an electromyogram. Results: The results showed that multiple courses of active tDCS can improve the cognitive functions of patients with AD, especially in the memory domain (word recall, recall of test instructions and word recognition). In addition, the damaged MEP level was enhanced following active treatment. In the active tDCS group, the improvements in ADAS-Cog total and subitem (word recall and word recognition) scores were negatively correlated with the enhancement of MEP. Conclusions: Our research indicates for the first time that twice-a-day tDCS may improve the cognitive function of patients with AD. This study also suggests that cognitive dysfunction may be related to impaired cortical plasticity, which warrants mechanistic investigations of the relationship between cognition and plasticity in the future. Trial registration number: ChiCTR1900021067.

Motor cortical plasticity as a predictor of treatment response to high frequency repetitive transcranial magnetic stimulation (rTMS) for cognitive function in drug-naive patients with major depressive disorder.

BACKGROUND: There is growing evidence that repetitive transcranial magnetic stimulation (rTMS) can improve cognitive function in patients with major depressive disorder (MDD). Few biomarkers are currently available to predict cognitive response in MDD patients. This study aimed to examine whether cortical plasticity played an important role in improving cognitive deficits in MDD patients treated with rTMS. METHODS: A total of 66 MDD patients and 53 healthy controls were recruited. MDD patients were randomly assigned to receive 10 Hz active or sham rTMS 5 days per week for 4 weeks. Cognitive function was assessed using the Repeatable Battery for assessing Neuropsychological Status (RBANS), while depressive symptoms were assessed with the Hamilton Rating Scale for Depression (HRSD-24) before and after treatment. We combined transcranial magnetic stimulation and muscle surface electrophysiological recording to measure plasticity in motor cortex areas in healthy controls at baseline and MDD patients before and after treatment. RESULTS: Compared with healthy controls, cortical plasticity was impaired in MDD patients. Moreover, cortical plasticity was correlated with RBANS total score at baseline in MDD patients. After 4-week 10 Hz rTMS treatment, the impaired cortical plasticity was restored to some extent. Interestingly, 10 Hz rTMS treatment produced effective therapeutic effects on immediate memory, attention, and RBANS total score. Pearson correlation analysis shows that improvements in plasticity were positively correlated with improvement of immediate memory and RBANS total score. CONCLUSIONS: Our results show for the first time that 10 Hz rTMS can effectively treat impaired cortical plasticity and cognitive impairment in MDD patients and that changes in plasticity and cognitive function are closely related, which may indicate that motor cortical plasticity may play a vital role in cognitive impairment and that cortical plasticity may serve as a potential predictive biomarker for cognitive improvement in MDD patients.

Cortical activation and functional connectivity during the verbal fluency task for adolescent-onset depression: A multi-channel NIRS study.

OBJECTIVE: Depression disorder is accompanied by cognitive impairments. However, there is limited research focused on cognitive impairments and their neurological mechanism in adolescents with depression. The purpose of the current study is to illustrate the differences in brain activity patterns between depressed adolescents and healthy controls (HCs). METHOD: A total of 72 adolescents with depression, as well as 74 HCs, were recruited. We utilized functional near-infrared spectroscopy (fNIRS) to monitor the concentrations of oxyhemoglobin (Oxy-Hb) in the brains of participants while they performed the verbal fluency task (VFT) to examine cognitive impairment in adolescents with depression. RESULTS: Our study demonstrated that adolescents with depression had significantly less cortical activation in the hemodynamic responses of Oxy-Hb at channels mainly located in the prefrontal cortex (PFC) than HCs during the 60-s task period (false discovery rate (FDR)-corrected p < 0.05). The mean channel-to-channel connectivity was 0.400 for HCs (SD = 0.149) and 0.303 (SD = 0.138) for adolescents with depression, and the HC group had a higher mean channel-to-channel connectivity strength than the depression group (t = -15.586, p < 0.001). For the patient group, we found significant negative correlations between HAMD scores and mean Oxy-Hb changes in Channel 38 (r = -0.33, p < 0.01), Channel 39 (r = -0.34, p < 0.01), Channel 41 (r = -0.25, p < 0.05), Channel 42 (r = -0.28, p < 0.05), and Channel 44 (r = -0.27, p < 0.05), and these channels were mainly located in areas with little difference between groups. CONCLUSIONS: Our study provides neurological evidence about the executive function (EF) in depressed adolescents. Adolescents with depression exhibited an abnormal activation pattern and decreased task-related functional connectivity compared to HCs. The changed Oxy-Hb concentration of PFC during VFT was not sensitive to depression symptoms.

Phthalorubines: Fused-Ring Compounds Synthesized from Phthalonitrile.

A series of dibenzo[a,f][1,3,5]triazino[2,1,6-cd] pyrrolizine compounds have been synthesized from phthalonitriles by a facile intramolecular cyclization process using "half-phthalocyanine" precursors, and they were characterized by X-ray crystallography, 1 H NMR spectroscopy, UV/Vis, and theoretical calculations. These compounds have spectroscopic profiles similar to phthalocyanines and porphyrins, although their inner-core structures and coordination types are totally different. They can be regarded as a new class of aromatic fused-ring compounds. The low-energy absorption of these new fused-ring compounds are located at around 600 nm. Such a low-energy π-π* transition is scarce in aromatic compounds having a similar molecular size. According to the nomenclature of phthalocyanines, these types of compounds have been named phthalorubines (Prs).