Breakdown of long-range temporal correlations in theta oscillations in patients with major depressive disorder

Neuroimaging has revealed robust large-scale patterns of high neuronal activity in the human brain in the classical eyes-closed wakeful rest condition, pointing to the presence of a baseline of sustained endogenous processing in the absence of stimulus-driven neuronal activity. This baseline state has been shown to differ in major depressive disorder. More recently, several studies have documented that despite having a complex temporal structure, baseline oscillatory activity is characterized by persistent autocorrelations for tens of seconds that are highly replicable within and across subjects. The functional significance of these long-range temporal correlations has remained unknown. We recorded neuromagnetic activity in patients with a major depressive disorder and in healthy control subjects during eyes-closed wakeful rest and quantified the long-range temporal correlations in the amplitude fluctuations of different frequency bands. We found that temporal correlations in the theta-frequency band (3-7 Hz) were almost absent in the 5-100 s time range in the patients but prominent in the control subjects. The magnitude of temporal correlations over the left temporocentral region predicted the severity of depression in the patients. These data indicate that long-range temporal correlations in theta oscillations are a salient characteristic of the healthy human brain and may have diagnostic potential in psychiatric disorders. We propose a link between the abnormal temporal structure of theta oscillations in the depressive patients and the systems-level impairments of limbic-cortical networks that have been identified in recent anatomical and functional studies of patients with major depressive disorder. Copyright © 2005 Society for Neuroscience

Paediatric prehospital emergencies and restrictions during the COVID-19 pandemic : A population-based study

Background Children are less vulnerable to serious forms of the COVID-19 disease. However, concerns have been raised about children being the second victims of the pandemic and its control measures. Therefore, we wanted to study if the pandemic, the infection control measures and their consequences to the society projected to paediatric prehospital emergency medical services (EMS) contacts. Methods We conducted a population-based cohort study concerning all children aged 0–15 years with EMS contacts in the Helsinki University Hospital area during 1 March 2020–31 May 2020 (study period) and equivalent periods in 2017–2019 (control periods). We analysed the demographic characteristics, time of EMS contact, reason for EMS contact, priority of the dispatch, reason for transportation, priority of transportation, if any consultations were made or additional units required, any medication or oxygen or fluids given, if intubation was performed, and whether paramedics took precautions when COVID-19 infection was suspected. Results The number of paediatric EMS contacts decreased by 30.4% from mean of 1794 contacts to 1369 (p=0.003). The EMS contacts were more often due to trauma (+23.7%, p<0.05), dispatched in the most urgent category (+139.9%, p=0.001), additional help and the mobile intensive care unit were more frequently requested (+43.3%, p=0.040 and+46.3%, p=0.049, respectively). However, EMS contacts resulted less often in ambulance transport (−21.1%, p<0.001). Alarmingly, there were four deaths during the study period compared with 0–2 during the control periods. Conclusions The number of EMS contacts decreased during the pandemic. Nevertheless, the children encountered by the EMS were more seriously ill than during the control periods.Peer reviewe