Low Functional network integrity in cognitively unimpaired and MCI subjects with depressive symptoms: results from a multi-center fMRI study.

Evidence suggests that depressive symptomatology is a consequence of network dysfunction rather than lesion pathology. We studied whole-brain functional connectivity using a Minimum Spanning Tree as a graph-theoretical approach. Furthermore, we examined functional connectivity in the Default Mode Network, the Frontolimbic Network (FLN), the Salience Network, and the Cognitive Control Network. All 183 elderly subjects underwent a comprehensive neuropsychological evaluation and a 3 Tesla brain MRI scan. To assess the potential presence of depressive symptoms, the 13-item version of the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) was utilized. Participants were assigned into three groups based on their cognitive status: amnestic mild cognitive impairment (MCI), non-amnestic MCI, and healthy controls. Regarding affective symptoms, subjects were categorized into depressed and non-depressed groups. An increased mean eccentricity and network diameter were found in patients with depressive symptoms relative to non-depressed ones, and both measures showed correlations with depressive symptom severity. In patients with depressive symptoms, a functional hypoconnectivity was detected between the Anterior Cingulate Cortex (ACC) and the right amygdala in the FLN, which impairment correlated with depressive symptom severity. While no structural difference was found in subjects with depressive symptoms, the volume of the hippocampus and the thickness of the precuneus and the entorhinal cortex were decreased in subjects with MCI, especially in amnestic MCI. The increase in eccentricity and diameter indicates a more path-like functional network configuration that may lead to an impaired functional integration in depression, a possible cause of depressive symptomatology in the elderly.

Alterations in resting-state gamma activity in patients with schizophrenia: a high-density EEG study.

Alterations of EEG gamma activity in schizophrenia have been reported during sensory and cognitive tasks, but it remains unclear whether changes are present in resting state. Our aim was to examine whether changes occur in resting state, and to delineate those brain regions where gamma activity is altered. Furthermore, we wanted to identify the associations between changes in gamma activity and psychopathological characteristics. We studied gamma activity (30-48 Hz) in 60 patients with schizophrenia and 76 healthy controls. EEGs were acquired in resting state with closed eyes using a high-density, 256-channel EEG-system. The two groups were compared in absolute power measures in the gamma frequency range. Compared to controls, in patients with schizophrenia the absolute power was significantly elevated (false discovery rate corrected p < 0.05). The alterations clustered into fronto-central and posterior brain regions, and were positively associated with the severity of psychopathology, measured by the PANSS. Changes in gamma activity can lead to disturbed coordination of large-scale brain networks. Thus, the increased gamma activity in certain brain regions that we found may result in disturbances in temporal coordination of task-free/resting-state networks in schizophrenia. Positive association of increased gamma power with psychopathology suggests that altered gamma activity provides a contribution to symptom presentation.

Is there any difference between the findings of Clock Drawing Tests if the clocks show different times?

BACKGROUND: The Clock Drawing Test (CDT) is a widely-used, rapid assessment tool for the screening of cognitive decline though its evaluation and interpretation are still not uniform. The aim of present study was to investigate the difference in sensitivity and specificity of two types of CDTs and to compare the clinical benefits of quantitative and semiquantitative scoring systems. OBJECTIVE: To investigate the difference in sensitivity and specificity of two types of CDTs and to compare the clinical benefits of quantitative and semiquantitative scoring systems. METHODS: Six hundred and ninety-two participants with or without dementia completed 10-item CDTs in nursing homes in two counties in southern Hungary. The dementia was not further subclassified. The results of the two tests, CDT1 (representing five minutes to a quarter to four) and CDT2 (representing ten past five), were evaluated quantitatively and semiquantitatively. RESULTS: In the quantitative evaluation, the sensitivity and the specificity for the diagnosis of dementia at cut-off scores of 7 points were determined: 87.1% and 51.9%, respectively, for CDT1, and 81.7% and 57% for CDT2, respectively. The semiquantitative analysis revealed a sensitivity of 67.3% and a specificity of 65.3% for CDT1, and of 64.6% and 66.6% for CDT2, respectively. CONCLUSION: The results of CDT tests do not appear to depend on the positions of the clock hands and additionally suggest that the quantitative evaluation method is more sensitive than the semiquantitative method.

[Designer drug induced psychosis]. / Dizájner drog indukálta pszichózis.

3,4-methylene-dioxy-pyrovalerone (MDPV) is a popular designer drug in Hungary, known as MP4. We present a case of a 34-year-old man, whose first psychotic episode was observed in the presence of MP4 use. The paranoid ideas of reference and the dereistic thinking could be the consequence of drug-induced psychosis. Within 24 hours after the intoxication was over delirium set in. The patient's history included only the use of MP4, use of other kinds of drugs was negated. The drug tests were negative, amphetamine derivates were not detectable in the urine sample. It is most likely that the MP4 pill contained an amount of MDPV less than detectable. In conclusion we suggest that the clinical picture could be the consequence of regular MDPV use.