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Accumulation of amyloid-β is a key neuropathological feature in brain of Alzheimer's disease patients. Alterations in cerebral haemodynamics, such as arterial impulse propagation driving the (peri)vascular CSF flux, predict future Alzheimer's disease progression. We now present a non-invasive method to quantify the three-dimensional propagation of cardiovascular impulses in human brain using ultrafast 10 Hz magnetic resonance encephalography. This technique revealed spatio-temporal abnormalities in impulse propagation in Alzheimer's disease. The arrival latency and propagation speed both differed in patients with Alzheimer's disease. Our mapping of arterial territories revealed Alzheimer's disease-specific modifications, including reversed impulse propagation around the hippocampi and in parietal cortical areas. The findings imply that pervasive abnormality in (peri)vascular CSF impulse propagation compromises vascular impulse propagation and subsequently glymphatic brain clearance of amyloid-β in Alzheimer's disease., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Narcolepsy is a chronic neurological disease characterized by dysfunction of the hypocretin system in brain causing disruption in the wake-promoting system. In addition to sleep attacks and cataplexy, patients with narcolepsy commonly report cognitive symptoms while objective deficits in sustained attention and executive function have been observed. Prior resting-state functional magnetic resonance imaging (fMRI) studies in narcolepsy have reported decreased inter/intranetwork connectivity regarding the default mode network (DMN). Recently developed fast fMRI data acquisition allows more precise detection of brain signal propagation with a novel dynamic lag analysis. In this study, we used fast fMRI data to analyze dynamics of inter resting-state network (RSN) information signaling between narcolepsy type 1 patients (NT1, n  = 23) and age- and sex-matched healthy controls (HC, n  = 23). We investigated dynamic connectivity properties between positive and negative peaks and, furthermore, their anticorrelative (pos-neg) counterparts. The lag distributions were significantly ( P  < 0.005, familywise error rate corrected) altered in 24 RSN pairs in NT1. The DMN was involved in 83% of the altered RSN pairs. We conclude that narcolepsy type 1 is characterized with delayed and monotonic inter-RSN information flow especially involving anticorrelations, which are known to be characteristic behavior of the DMN regarding neurocognition., (© The Author(s) 2020. Published by Oxford University Press.)

Resting-state functional MRI has shown potential for detecting changes in cerebral blood oxygen level-dependent signal in patients with epilepsy, even in the absence of epileptiform activity. Furthermore, it has been suggested that coefficient of variation mapping of fast functional MRI signal may provide a powerful tool for the identification of intrinsic brain pulsations in neurological diseases such as dementia, stroke and epilepsy. In this study, we used fast functional MRI sequence (magnetic resonance encephalography) to acquire ten whole-brain images per second. We used the functional MRI data to compare physiological brain pulsations between healthy controls ( n  = 102) and patients with epilepsy ( n  = 33) and furthermore to drug-naive seizure patients ( n  = 9). Analyses were performed by calculating coefficient of variation and spectral power in full band and filtered sub-bands. Brain pulsations in the respiratory-related frequency sub-band (0.11-0.51 Hz) were significantly ( P  <   0.05) increased in patients with epilepsy, with an increase in both signal variance and power. At the individual level, over 80% of medicated and drug-naive seizure patients exhibited areas of abnormal brain signal power that correlated well with the known clinical diagnosis, while none of the controls showed signs of abnormality with the same threshold. The differences were most apparent in the basal brain structures, respiratory centres of brain stem, midbrain and temporal lobes. Notably, full-band, very low frequency (0.01-0.1 Hz) and cardiovascular (0.8-1.76 Hz) brain pulses showed no differences between groups. This study extends and confirms our previous results of abnormal fast functional MRI signal variance in epilepsy patients. Only respiratory-related brain pulsations were clearly increased with no changes in either physiological cardiorespiratory rates or head motion between the subjects. The regional alterations in brain pulsations suggest that mechanisms driving the cerebrospinal fluid homeostasis may be altered in epilepsy. Magnetic resonance encephalography has both increased sensitivity and high specificity for detecting the increased brain pulsations, particularly in times when other tools for locating epileptogenic areas remain inconclusive., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Aims: The objective is to study whether a heart rate (HR) increase from 40 to 100% of maximal work capacity in the exercise test (HR40-100) independently predicts mortality in men with known or suspected coronary heart disease (CHD)., Methods and Results: The subjects were 294 men, 42-61 years of age, from eastern Finland with known or suspected CHD but without use of HR-lowering medication at baseline. HR was measured at rest and during a maximal, symptom-limited exercise test. During an average follow-up of 11.0 years, there were 61 all-cause deaths. In Cox-multivariable model, mortality increased by 41% (95% confidence interval, 12-79%) with a 1-SD (15 b.p.m.) decrement in HR40-100. HR increase from rest to 40% of maximal work capacity was not associated with an increased risk of death. Synergism was observed between HR40-100 and workload achieved at HR of 100 b.p.m. so that men having low values for both these HR variables had a particularly adverse prognosis compared with men with high values for these variables., Conclusion: An attenuated HR increase particularly during the latter half of a maximal exercise test is an independent predictor of death in men with known or suspected CHD.

This study aimed to develop a theoretical basis for the promotion of school staff's occupational well-being. The 'Content Model for the Promotion of School Community Staff's Occupational Well-being' describes the four aspects of the promotion of occupational well-being ('working conditions', 'worker and work', 'working community' and 'professional competence') as well as the functionality and structure of the model. The content model was examined empirically by means of a structural equation model. The project was developed with school staff and occupational health nurses and implemented in 2001-2004. The target group consisted of the staff of 12 comprehensive schools in Eastern Finland in 2002 (n = 211) and 2004 (n = 266). The data were collected using a 'well-being at your work index' questionnaire at both times. A structural equation model for the school staff's occupational well-being, i.e. the 'Occupational Well-being of School Staff Model' (baseline OWSS Model: Study I in the year 2002), was produced. The model was tested with the 2004 data. Based on this, the model was further developed into the final OWSS Model (Study II). The theoretical Content Model for the Promotion of School Community Staff's Occupational Well-being can be used as a framework for planning, implementing and evaluating school staff's occupational well-being.