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"Higgins, Amy"
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Heterogeneity of Outcomes and Network Connectivity in Early-Stage Psychosis: A Longitudinal Study
by
Hwang, Melissa
,
Brady, Roscoe
,
Hall, Mei-Hua
in
Cluster analysis
,
Connectivity
,
Longitudinal studies
2021
Abstract
Imaging studies in psychotic disorders typically examine cross-sectional relationships between magnetic resonance imaging (MRI) signals and diagnosis or symptoms. We sought to examine changes in network connectivity identified using resting-state functional MRI (fMRI) corresponding to divergent functional recovery trajectories and relapse in early-stage psychosis (ESP). Prior studies have linked schizophrenia to hyperconnectivity in the default mode network (DMN). Given the correlations between the DMN and behavioral impairments in psychosis, we hypothesized that dynamic changes in DMN connectivity reflect the heterogeneity of outcomes in ESP. Longitudinal data were collected from 66 ESP patients and 20 healthy controls. Longitudinal cluster analysis identified subgroups of patients with similar trajectories in terms of symptom severity and functional outcomes. DMN connectivity was measured in a subset of patients (n = 36) longitudinally over 2 scans separated by a mean of 12 months. We then compared connectivity between patients and controls, and among the different outcome trajectory subgroups. Among ESP participants, 4 subgroups were empirically identified corresponding to: “Poor,” “Middle,” “Catch-up,” and “Good” trajectory outcomes in the complete dataset (n = 36), and an independent replication (n = 30). DMN connectivity changes differed significantly between functional subgroups (F3,32 = 6.06, P-FDR corrected = .01); DMN connectivity increased over time in the “Poor” outcome cluster (β = +0.145) but decreased over time in the “Catch-up” cluster (β = −0.212). DMN connectivity is dynamic and correlates with a change in functional status over time in ESP. This approach identifies a brain-based marker that reflects important neurobiological processes required to sustain functional recovery.
Journal Article
The Entrepreneurs: Dairy farmer perspectives on finding an industry solution for the surplus calf issue—A participatory case study
2022
Current systems for managing surplus dairy calves are wrought with ethical and animal welfare concerns. Resolving complex problems in the dairy industry requires engagement from dairy farmers and other stakeholders. The main objective of this case study was to pilot a novel methodology to deepen our understanding of how dairy producers envision the future of surplus calves in Atlantic Canada, including identifying who they felt were important to speak to as they discussed this topic. A second objective was to understand the perspectives of a key group the producers requested to speak to, representing a variety of dairy industry partners, including veterinarians, genetics companies, and animal welfare scientists amongst others (referred to as the allied industry) on the future of surplus calves. To reach these objectives, we used an inclusive participatory approach that, to our knowledge, has not yet been applied to the surplus calf issue. This approach included a series of five participatory group discussions with volunteer dairy farmers from Atlantic Canada; the allied industry group was invited to two group discussions. Participants discussed the feasibility of creating a dairy beef system as a potential solution to the surplus dairy calf issue. During the discussions, participants were encouraged to make requests to speak to individuals that would help them design a dairy beef system. Audio-recorded transcripts were subjected to inductive qualitative content analysis where short descriptors were assigned to pieces of the discussion relevant to study objectives. Four key themes from the discussions included: (1) challenges with surplus calf production on the dairy farm, such as a lack of knowledge about what type of calf would be desired by the marketplace, (2) the role of leadership and partnership in the creation of a dairy beef system, including the need to overcome communication barriers between different stakeholders, (3) post-farm gate aspects of surplus calf production, including the desire to cater to a local market, and (4) ensuring that the proposed system is economically and socially viable. Knowledge gained from this type of participatory engagement can help stakeholders align their goals to resolve complex issues such as surplus calf management.
Journal Article
Sensory gating, neurocognition, social cognition and real-life functioning: a 2-year follow-up of early psychosis
2023
Diminished sensory gating (SG) is a robust finding in psychotic disorders, but studies of early psychosis (EP) are rare. It is unknown whether SG deficit leads to poor neurocognitive, social, and/or real-world functioning. This study aimed to explore the longitudinal relationships between SG and these variables.
Seventy-nine EP patients and 88 healthy controls (HCs) were recruited at baseline. Thirty-three and 20 EP patients completed 12-month and 24-month follow-up, respectively. SG was measured using the auditory dual-click (S1 & S2) paradigm and quantified as P50 ratio (S2/S1) and difference (S1-S2). Cognition, real-life functioning, and symptoms were assessed using the MATRICS Consensus Cognitive Battery, Global Functioning: Social (GFS) and Role (GFR), Multnomah Community Ability Scale (MCAS), Awareness of Social Inference Test (TASIT), and the Positive and Negative Syndrome Scale (PANSS). Analysis of variance (ANOVA), chi-square, mixed model, correlation and regression analyses were used for group comparisons and relationships among variables controlling for potential confounding variables.
In EP patients, P50 ratio (
< 0.05) and difference (
< 0.001) at 24-month showed significant differences compared with that at baseline. At baseline, P50 indices (ratio, S1-S2 difference, S1) were independently associated with GFR in HCs (all
< 0.05); in EP patients, S2 amplitude was independently associated with GFS (
= 0.037). At 12-month and 24-month, P50 indices (ratio, S1, S2) was independently associated with MCAS (all
< 0.05). S1-S2 difference was a trending predictor of future function (GFS or MCAS).
SG showed progressive reduction in EP patients. P50 indices were related to real-life functioning.
Journal Article
Dynamic and progressive changes in thalamic functional connectivity over the first five years of psychosis
by
Brady, Roscoe O
,
Lewandowski, Kathryn E
,
Dost, Öngür
in
Cerebellum
,
Cognitive ability
,
Critical period
2022
The early stage of psychosis (ESP) is a critical period where effective intervention has the most favorable impact on outcomes. Thalamic connectivity abnormalities have been consistently found in psychosis, and are associated with clinical symptoms and cognitive deficits. However, most studies consider ESP patients as a homogeneous population and fail to take the duration of illness into account. In this study, we aimed to capture the progression of thalamic connectivity changes over the first five years of psychosis. Resting-state functional MRI scans were collected from 156 ESP patients (44 with longitudinal data) and 82 healthy controls (24 with longitudinal data). We first performed a case-control analysis comparing thalamic connectivity with 13 networks in the cortex and cerebellum. Next, we modelled the shape (flat, linear, curvilinear) of thalamic connectivity trajectories by comparing flexible non-linear versus linear models. We then tested the significance of the duration of illness and diagnosis in trajectories that changed over time. Connectivity changed over the ESP period between the thalamus and default mode network (DMN) and fronto-parietal network (FPN) nodes in both the cortex and cerebellum. Three models followed a curvilinear trajectory (early increase followed by a subsequent decrease), while thalamo-cerebellar FPN connectivity followed a linear trajectory of steady reductions over time, indicating different rates of change. Finally, diagnosis significantly predicted thalamic connectivity. Thalamo-cortical and thalamo-cerebellar connectivity change in a dynamic fashion during the ESP period. A better understanding of these changes may provide insights into the compensatory and progressive changes in functional connectivity in the early stages of illness.
Journal Article
Uncovering key predictive channels and clinical variables in the gamma band auditory steady-state response in early-stage psychosis: a longitudinal study
2024
Psychotic disorders are characterised by abnormalities in the synchronisation of neuronal responses. A 40 Hz gamma band deficit during auditory steady-state response (ASSR) measured by electroencephalogram (EEG) is a robust observation in psychosis and is associated with symptoms and functional deficits. However, the majority of ASSR studies focus on specific electrode sites, while whole scalp analysis using all channels, and the association with clinical symptoms, are rare.
In this study, we use whole-scalp 40 Hz ASSR EEG measurements – power and phase-locking factor – to establish deficits in early-stage psychosis (ESP) subjects, classify ESP status using an ensemble of machine learning techniques, identify correlates with principal components obtained from clinical/demographic/functioning variables, and correlate functional outcome after a short-term follow-up.
We identified significant spatially-distributed group level differences for power and phase locking. The performance of different machine learning techniques and interpretation of the extracted feature importance indicate that phase locking has a more predictive and parsimonious pattern than power. Phase locking is also associated with principal components composed of measures of cognitive processes. Short-term functional outcome is associated with baseline 40 Hz ASSR signals from the FCz and other channels in both phase locking and power.
This whole-scalp EEG study provides additional evidence to link deficits in 40 Hz ASSRs with cognition and functioning in ESP, and corroborates with prior studies of phase locking from a subset of EEG channels. Confirming 40 Hz ASSR deficits serves as a candidate phenotype to identify circuit dysfunctions and a biomarker for clinical outcomes in psychosis.
Journal Article
Work-Life Balance Best Practices
2020
Poor balance between workplace and family life has been shown to increase stress and impact emotional well-being. Nurses continue to report burnout and high stress levels from time spent in the workplace which contributes to an inability to balance work with life. The gap in nursing practice leadership is the lack of knowledge and tools for supporting the emotional well-being of managers and direct care nursing staff. The purpose of this systematic review was to compile a summary of rigorous evidence-based literature on programs and strategies that nursing leaders can use to provide support in achieving work-life balance for nursing staff. Guided by Cooper’s seven step process for research synthesis, a total of 18 articles were chosen that pertained to key elements of sustaining balance between the workplace and personal life. Evidence-based options that make a difference include flexible staffing, stress management programs, and personal health and wellness programs. There is evidence these activities are valuable in maintaining optimal productivity and retention. Improving the autonomy and support perceived by nurses while eliminating pressures such as increased productivity and higher workloads can improve the nursing experience, ultimately improving patient experience and outcomes. This information can be used by nurse leaders to create and implement strategies to support the nursing workforce and ultimately decrease the turnover and the loss of experienced nurses from the profession. This project facilitates positive social change by contributing to a supportive work environment that allows nurses to provide quality patient care.
Dissertation