Abnormal connectivity between the default mode and the visual system underlies the manifestation of visual hallucinations in Parkinson’s disease:A task-based fMRI study

Background: The neural substrates of visual hallucinations remain an enigma, due primarily to the difficulties associated with directly interrogating the brain during hallucinatory episodes. Aims: To delineate the functional patterns of brain network activity and connectivity underlying visual hallucinations in Parkinson’s disease. Methods: In this study, we combined functional magnetic resonance imaging (MRI) with a behavioral task capable of eliciting visual misperceptions, a confirmed surrogate for visual hallucinations, in 35 patients with idiopathic Parkinson’s disease. We then applied an independent component analysis to extract time series information for large-scale neuronal networks that have been previously implicated in the pathophysiology of visual hallucinations. These data were subjected to a task-based functional connectivity analysis, thus providing the first objective description of the neural activity and connectivity during visual hallucinations in patients with Parkinson’s disease. Results: Correct performance of the task was associated with increased activity in primary visual regions; however, during visual misperceptions, this same visual network became actively coupled with the default mode network (DMN). Further, the frequency of misperception errors on the task was positively correlated with the strength of connectivity between these two systems, as well as with decreased activity in the dorsal attention network (DAN), and with impaired connectivity between the DAN and the DMNs, and ventral attention networks. Finally, each of the network abnormalities identified in our analysis were significantly correlated with two independent clinical measures of hallucination severity. Conclusions: Together, these results provide evidence that visual hallucinations are due to increased engagement of the DMN with the primary visual system, and emphasize the role of dysfunctional engagement of attentional networks in the pathophysiology of hallucinations

A qualitative exploration of the emotional wellbeing and support needs of new mothers from Afghanistan living in Melbourne, Australia

Background: The Afghan community is a priority population for many health and social services within the southeast region of Melbourne, which is home to the largest population of Afghanistan-born people within the state of Victoria. The majority of Afghan women arriving in Australia are of childbearing age, and evidence suggests that they are at increased risk of emotional challenges following birth as a result of the refugee and migration experience. This research aimed to explored the experiences of Afghan women living in Melbourne throughout pregnancy, birth, and early motherhood, and gain insight into the aspects of their experiences that they perceive as positively and negatively impacting their emotional wellbeing. Methods: This qualitative study collected data through two focus group discussions (conducted in Dari) and 10 in-depth interviews (conducted in Dari or English). Thirty-eight Afghanistan-born women aged 18 years and older, who recently migrated to Australia and have at least one Australian-born child, were purposively selected to participate. A trained bicultural worker assisted in recruitment, data collection and translation. Thematic analysis was performed, and findings were confirmed with a subgroup of participants prior to being included within reporting. Results: Participants consistently discussed experiencing emotional challenges following birth, identifying symptoms commonly associated with postnatal depression. Women largely attributed this emotional state to separation from family and culture, leading to loneliness, isolation, and disconnection. Participants expressed resistance towards professional support due to cultural stigma associated with mental illness. Partner support was seen to be positive but difficult to negotiate. Religion, strong relationship with child, forming friendships, education, and utilising childcare were identified as positive influences on the emotional wellbeing of women. Conclusions: This study highlighted social and cultural factors contributing towards the emotional wellbeing of Afghan mothers. Findings confirm the need for innovative community-based models to support the mental health of Afghan women. This is particularly pertinent given the identified resistance towards discussing emotional wellbeing with healthcare professionals. Further research and investment is required in this area

Changes in structural network topology correlate with severity of hallucinatory behavior in Parkinson's disease

Inefficient integration between bottom-up visual input and higher order visual processing regions is implicated in visual hallucinations in Parkinson's disease (PD). Here, we investigated white matter contributions to this perceptual imbalance hypothesis. Twenty-nine PD patients were assessed for hallucinatory behavior. Hallucination severity was correlated to connectivity strength of the network using the network-based statistic approach. The results showed that hallucination severity was associated with reduced connectivity within a subnetwork that included the majority of the diverse club. This network showed overall greater between-module scores compared with nodes not associated with hallucination severity. Reduced between-module connectivity in the lateral occipital cortex, insula, and pars orbitalis and decreased within-module connectivity in the prefrontal, somatosensory, and primary visual cortices were associated with hallucination severity. Conversely, hallucination severity was associated with increased between- and within-module connectivity in the orbitofrontal and temporal cortex, as well as regions comprising the dorsal attentional and default mode network. These results suggest that hallucination severity is associated with marked alterations in structural network topology with changes in participation along the perceptual hierarchy. This may result in the inefficient transfer of information that gives rise to hallucinations in PD. Author SummaryInefficient integration of information between external stimuli and internal perceptual predictions may lead to misperceptions or visual hallucinations in Parkinson's disease (PD). In this study, we show that hallucinatory behavior in PD patients is associated with marked alterations in structural network topology. Severity of hallucinatory behavior was associated with decreased connectivity in a large subnetwork that included the majority of the diverse club, nodes with a high number of between-module connections. Furthermore, changes in between-module connectivity were found across brain regions involved in visual processing, top-down prediction centers, and endogenous attention, including the occipital, orbitofrontal, and posterior cingulate cortex. Together, these findings suggest that impaired integration across different sides across different perceptual processing regions may result in inefficient transfer of information

Family planning and Afghan refugee women and men living in Melbourne, Australia: new opportunities and transcultural tensions

This research aimed to explore the family planning perspectives and experiences of Afghan women and men living in Melbourne. A total of 57 Afghan women and men participated in six focus groups and 20 semi-structured interviews. The majority of participants indicated a preference for two or three children and were open to using modern contraception. However, many women described experiencing negative side effects when using hormone-based contraception and expressed difficulty negotiating condom use with their husbands as an alternative. Some women described how these difficulties resulted in inconsistent contraceptive practices and, at times, unintended pregnancy. Participants recognised that health professionals have an important role in addressing their family planning needs. This study highlights the ways in which Afghan women and men are changing in relation to their family planning beliefs and practices, and the opportunities, challenges and transcultural tensions they experience as they navigate these issues in Australia

Afro-Orientalism: An Exploration of the Relationship Between African Americans and the Japanese from the 18th to the 21st Century

The study of Afro-Asian relationships, often referred to as Afro-Orientalism, is a subject that is not widely discussed. This relationship is a cultural and often political interaction of two vastly different cultures, that have found a common identity and connectedness between themselves even across oceans. My honors thesis will specifically address the Afro-Asian relationship between African Americans in the United States and Japanese people. The benefit of the previous research that has been done in this study is that it sets the foundation for Afro-Orientalism. Additionally, those who have explored in this area have explicated the specific problems that fester as a manifestation of this Afro-Asian relationship such as the World Color Line. However, it fails to address the development of the Afro-Asian relationship from 1902 in comparison to the 21st century. It is important to understand how the dynamics between cultures and their interconnectedness with one another develop with changing cultural ideologies over time. This paper will extend beyond the existing scholarship about cultural politics and the critical problem of the World Color Line. It will address the relationship in the early 20th to early 21st century to explore how new frameworks of cultural understanding has changed the dynamics between the two cultures. To do this I will primarily look at Bill Mullin’s “Afro-Orientalism”, Gerald Home’s “Facing the Rising Sun: African Americans, Japan, and the Rise of Afro-Asian Solidarity”, Tze-Yue G. Hu’s “Frames of Anime: Culture and Image-Building”, and W.E.B. Du Bois’s “Black Princess”, as well as the anime “Afro- Samurai” by Takashi Okazaki

Racial Differences in Cardiovascular Biomarkers in the General Population

Background-The incidence and clinical manifestations of cardiovascular disease (CVD) differ between blacks and whites. Biomarkers that reflect important pathophysiological pathways may provide a window to allow deeper understanding of racial differences in CVD. Methods and Results-The study included 2635 white and black participants from the Dallas Heart Study who were free from existing CVD. Cross-sectional associations between race and 32 biomarkers were evaluated using multivariable linear regression adjusting for age, traditional CVD risk factors, imaging measures of body composition, renal function, insulin resistance, left ventricular mass, and socioeconomic factors. In fully adjusted models, black women had higher lipoprotein(a), leptin, D-dimer, osteoprotegerin, antinuclear antibody, homoarginine, suppression of tumorigenicity-2, and urinary microalbumin, and lower adiponectin, soluble receptor for advanced glycation end products and N-terminal pro-B-type natriuretic peptide versus white women. Black men had higher lipoprotein(a), leptin, D-dimer, high-sensitivity C-reactive protein, antinuclear antibody, symmetrical dimethylarginine, homoarginine, high-sensitivity cardiac troponin T, suppression of tumorigenicity-2, and lower adiponectin, soluble receptor for advanced glycation end products, and N-terminal pro-B-type natriuretic peptide versus white men. Adjustment for biomarkers that were associated with higher CVD risk, and that differed between blacks and whites, attenuated the risk for CVD events in black women (unadjusted hazard ratio 2.05, 95% CI 1.32, 3.17 and adjusted hazard ratio 1.15, 95% CI 0.69, 1.92) and black men (unadjusted hazard ratio 2.39, 95% CI 1.64, 3.46, and adjusted hazard ratio 1.21, 95% CI 0.76, 1.95). Conclusions-Significant racial differences were seen in biomarkers reflecting lipids, adipokines, and biomarkers of endothelial function, inflammation, myocyte injury, and neurohormonal stress, which may contribute to racial differences in the development and complications of CVD

Cognitive training for freezing of gait in Parkinson's disease: a randomized controlled trial.

The pathophysiological mechanism of freezing of gait (FoG) has been linked to executive dysfunction. Cognitive training (CT) is a non-pharmacological intervention which has been shown to improve executive functioning in Parkinson's disease (PD). This study aimed to explore whether targeted CT can reduce the severity of FoG in PD. Patients with PD who self-reported FoG and were free from dementia were randomly allocated to receive either a CT intervention or an active control. Both groups were clinician-facilitated and conducted twice-weekly for seven weeks. The primary outcome was percentage of time spent frozen during a Timed Up and Go task, assessed both on and off dopaminergic medications. Secondary outcomes included multiple neuropsychological and psychosocial measures. A full analysis was first conducted on all participants randomized, followed by a sample of interest including only those who had objective FoG at baseline, and completed the intervention. Sixty-five patients were randomized into the study. The sample of interest included 20 in the CT group and 18 in the active control group. The primary outcome of percentage time spent frozen during a gait task was significantly improved in the CT group compared to active controls in the on-state. There were no differences in the off-state. Patients who received CT also demonstrated improved processing speed and reduced daytime sleepiness compared to those in the active control. The findings suggest that CT can reduce the severity of FoG in the on-state, however replication in a larger sample is required

Inflation convergence in Central and Eastern Europe vs. the Eurozone: Non-linearities and long memory

In this paper, we consider inflation rate differentials between seven Central and Eastern European Countries (CEECs) and the Eurozone. We test for convergence in the inflation rate differentials, incorporating non-linearities in the autoregressive parameters, fractional integration with endogenous structural changes, and also consider club convergence analysis for the CEECs over the period 1997 to 2015 based on monthly data. Our empirical findings suggest that the majority of countries experience non-linearities in the inflation rate differential; however, there is only evidence of a persistent difference in some countries. Complementary to this analysis we apply the Phillips and Sul (2007) test for club convergence and find that there is evidence that most of the CEECs converge to a common steady state

Mirror Symmetric Bimanual Movement Priming Can Increase Corticomotor Excitability and Enhance Motor Learning

Repetitive mirror symmetric bilateral upper limb may be a suitable priming technique for upper limb rehabilitation after stroke. Here we demonstrate neurophysiological and behavioural after-effects in healthy participants after priming with 20 minutes of repetitive active-passive bimanual wrist flexion and extension in a mirror symmetric pattern with respect to the body midline (MIR) compared to an control priming condition with alternating flexion-extension (ALT). Transcranial magnetic stimulation (TMS) indicated that corticomotor excitability (CME) of the passive hemisphere remained elevated compared to baseline for at least 30 minutes after MIR but not ALT, evidenced by an increase in the size of motor evoked potentials in ECR and FCR. Short and long-latency intracortical inhibition (SICI, LICI), short afferent inhibition (SAI) and interhemispheric inhibition (IHI) were also examined using pairs of stimuli. LICI differed between patterns, with less LICI after MIR compared with ALT, and an effect of pattern on IHI, with reduced IHI in passive FCR 15 minutes after MIR compared with ALT and baseline. There was no effect of pattern on SAI or FCR H-reflex. Similarly, SICI remained unchanged after 20 minutes of MIR. We then had participants complete a timed manual dexterity motor learning task with the passive hand during, immediately after, and 24 hours after MIR or control priming. The rate of task completion was faster with MIR priming compared to control conditions. Finally, ECR and FCR MEPs were examined within a pre-movement facilitation paradigm of wrist extension before and after MIR. ECR, but not FCR, MEPs were consistently facilitated before and after MIR, demonstrating no degradation of selective muscle activation. In summary, mirror symmetric active-passive bimanual movement increases CME and can enhance motor learning without degradation of muscle selectivity. These findings rationalise the use of mirror symmetric bimanual movement as a priming modality in post-stroke upper limb rehabilitation