State-like changes in the salience network correlate with delusion severity in first-episode psychosis patients

Background and hypothesis: Delusions are characteristic of psychotic disorders; however, the brain correlates of delusions remain poorly known. Imaging studies on delusions typically compare images across individuals. Related confounding of inter-individual differences beyond delusions may be avoided by comparing delusional and non-delusional states within individuals. Study design: We studied correlations of delusions using intra-subject correlation (intra-SC) and inter-subject correlation of functional magnetic resonance imaging (fMRI) signal time series, obtained during a movie stim-ulus at baseline and follow-up. We included 27 control subjects and 24 first-episode psychosis patients, who were free of delusions at follow-up, to calculate intra-SC between fMRI signals obtained during the two time points. In addition, we studied changes in functional connectivity at baseline and during the one-year follow-up using regions where delusion severity correlated with intra-SC as seeds. Results: The intra-SC correlated negatively with the baseline delusion severity in the bilateral anterior insula. In addition, we observed a subthreshold cluster in the anterior cingulate. These three regions constitute the cortical salience network (SN). Functional connectivity between the bilateral insula and the precuneus was weaker in the patients at baseline than in patients at follow-up or in control subjects at any time point. Conclusions: The results suggest that intra-SC is a powerful tool to study brain correlates of symptoms and highlight the role of the SN and internetwork dysconnectivity between the SN and the default mode network in delusions.Peer reviewe

Advances in non-invasive blood pressure measurement techniques

Hypertension, or elevated blood pressure (BP), is a marker for many cardiovascular diseases and can lead to life threatening conditions such as heart failure, coronary artery disease and stroke. Several techniques have recently been proposed and investigated for non-invasive BP monitoring. The increasing desire for telemonitoring solutions that allow patients to manage their own conditions from home has accelerated the development of new BP monitoring techniques. In this review, we present the recent progress in non-invasive blood pressure monitoring solutions emphasizing clinical validation and trade-offs between available techniques. We introduce the current BP measurement techniques with their underlying operating principles. New promising proof-of-concept studies are presented and recent modeling and machine learning approaches for improved BP estimation are summarized. This aids discussions on how new BP monitors should evaluated in order to bring forth new home monitoring solutions in wearable form factor. Finally, we discuss on unresolved challenges in making convenient, reliable and validated BP monitoring solutions.</p

Connectivity alterations of mesostriatal pathways in first episode psychosis

Background and hypothesisPathogenic understanding of the psychotic disorders converges on regulation of dopaminergic signaling in mesostriatocortical pathways. Functional connectivity of the mesostriatal pathways may inform us of the neuronal networks involved.Study designThis longitudinal study of first episode psychosis (FEP) (49 patients, 43 controls) employed seed-based functional connectivity analyses of fMRI data collected during a naturalistic movie stimulus.Study resultsWe identified hypoconnectivity of the dorsal striatum with the midbrain, associated with antipsychotic medication dose in FEP, in comparison with the healthy control group. The midbrain regions that showed hypoconnectivity with the dorsal striatum also showed hypoconnectivity with cerebellar regions suggested to be involved in regulation of the mesostriatocortical dopaminergic pathways. None of the baseline hypoconnectivity detected was seen at follow-up.ConclusionsThese findings extend earlier resting state findings on mesostriatal connectivity in psychotic disorders and highlight the potential for cerebellar regulation of the mesostriatocortical pathways as a target of treatment trials.Peer reviewe

Clinical assessment of a non-invasive wearable MEMS pressure sensor array for monitoring of arterial pulse waveform, heart rate and detection of atrial fibrillation

There is an unmet clinical need for a low cost and easy to use wearable devices for continuous cardiovascular health monitoring. A flexible and wearable wristband, based on microelectromechanical sensor (MEMS) elements array was developed to support this need. The performance of the device in cardiovascular monitoring was investigated by (i) comparing the arterial pressure waveform recordings to the gold standard, invasive catheter recording (n = 18), (ii) analyzing the ability to detect irregularities of the rhythm (n = 7), and (iii) measuring the heartrate monitoring accuracy (n = 31). Arterial waveforms carry important physiological information and the comparison study revealed that the recordings made with the wearable device and with the gold standard device resulted in almost identical (r = 0.9-0.99) pulse waveforms. The device can measure the heart rhythm and possible irregularities in it. A clustering analysis demonstrates a perfect classification accuracy between atrial fibrillation (AF) and sinus rhythm. The heartrate monitoring study showed near perfect beat-to-beat accuracy (sensitivity = 99.1%, precision = 100%) on healthy subjects. In contrast, beat-to-beat detection from coronary artery disease patients was challenging, but the averaged heartrate was extracted successfully (95% CI: -1.2 to 1.1 bpm). In conclusion, the results indicate that the device could be useful in remote monitoring of cardiovascular diseases and personalized medicine

Design and Implementation of a Wearable Sensor Node for Monitoring Mechanocardiographic Phenomena

Cardiovascular diseases are the most common cause of death in the world, fortunately most of which could be prevented. As the population ages, these conditions get even more frequent leading to millions of deaths every year. Atrial fibrillation (AF) is the most common arrhythmia (irregular heartbeat) affecting nearly 9 million people in the European Union only. Ischemic stroke is the most feared condition caused by AF with a five-fold risk of occurrence among AF patients. Commonly asymptomatic nature of AF causes many people to be left untreated. Mechanocardiography, including seismo-, ballisto- and gyrocardiography is the study of mechanical motion caused by cardiac activity. The quality of electromechanical sensors (accelerometers and gyroscopes) has improved greatly over the last decade due to MEMS (Microelectromechanical System) technology. The suitability of mechanocardiography for detecting AF has been assessed with promising results. In this thesis, a wearable sensor node for measuring the heart utilizing mechanocardiography is proposed. The device consists of a Bluetooth enabled MCU (Microcontroller unit), an IMU (Inertial Measurement Unit) and a 64-Mbit flash memory. The workflow of the design and implementation is documented in a reproducible manner. Verification is done by conducting both power consumption and mechanocardiographic measurements. Real time signal processing to detect AF is implemented as a proof-of-concept work to study the possibility for an independent AF detection device. As described in the thesis, the design was successfully implemented and provided high quality mechanocardiographic data. Minor improvements are proposed and possibility of a follow-up study is discussed along with potential for commercialization. A conference article based on this thesis was published in IEEE International Conference on Electronics Circuits and Systems (ICECS) in December 2018

CinC 2019

The aim of the study was to develop an automated device for recording peripheral arterial pulse wave, in order to assess cardiovascular health. Recent studies have shown that photoplethysmography (PPG) is a viable technique to measure peripheral pressure waveform. We developed a small motorized device that can measure pulse waveform from a finger. The device targets the distal transverse palmar arch (DTPA) artery using infrared wavelength PPG. Measurements were taken from healthy subjects (n = 8).The device was validated by performing HR detection and waveform analysis. The device was able to record high quality blood pressure calibrated arterial waveforms and detect beat-to-beat heart rate allowing the assessment of cardiovascular health status.</p

Associations between acceptance of the implausible bias, theory of mind and delusions in first-episode psychosis patients; A longitudinal study

Funding Information: This work was supported by the Sigrid Jusélius Foundation (J.S.), the Finnish Cultural Foundation (J.S.), the Medical Society of Finland (J.M.P.), the Academy of Finland (grants # 278171 and # 323035 to J.S. and # 315861 to T.T.R.), the Finnish Medical Foundation (J.M.P. and T.T.R.), state funding for university-level health research ( Hospital District of Helsinki and Uusimaa # TYH2013332 , # TYH2014228 , # TYH2017128 to T.K.), and the European Union's Seventh Framework Programme for project METSY (# 602478 to J.S.).Multiple different cognitive biases, among them the liberal acceptance (LA) bias, have been suggested to contribute to reality distortion in psychotic disorders. Earlier studies have been cross-sectional and considered a limited set of cognitive correlates of psychosis, thus the relationship between LA bias and psychosis remains poorly known. We studied a similar bias (acceptance of the implausible (AOI)) in 62 first-episode psychosis (FEP) patients and 62 control subjects, who watched movie scenes with varying degrees of realism and were asked to evaluate the probability of these events occurring in real life. We assessed theory of mind (ToM) performance using the Hinting task and delusion severity using Brief Psychiatric Rating Scale item 11. We correlated the magnitude of AOI with the severity of delusions and performance in the ToM task. Furthermore, we used 1-year follow-up data from 40 FEP patients and 40 control subjects to disentangle state vs trait-like characteristics of AOI. At baseline FEP patients expressed more AOI than control subjects, and the magnitude of AOI correlated positively with the severity of delusions and negatively with ToM performance. At the one-year follow-up, when most patients were in remission, patients still displayed increased AOI, which no longer correlated with delusions. These findings support the notion that the AOI bias could represent a trait rather than a state feature and support further studies to test the hypothesis that it could be one of the causal factors of psychotic disorders, possibly associated with ToM.Peer reviewe