Opponent intrinsic brain network connectivity profiles associated with posttraumatic fear and dysphoria symptoms in trauma-exposed refugees

OBJECTIVE

Resting-state functional magnetic resonance imaging (rsfMRI) studies report functional alterations in the connectivity between intrinsic brain networks in posttraumatic stress disorder (PTSD), but PTSD heterogeneity is rarely considered. Evidence points to fear (e.g., reexperiencing) and dysphoria (e.g., withdrawal) symptom factors as important in PTSD presentations, including relating to variable emotion dysregulation patterns. This study, therefore, tested how fear and dysphoria posttraumatic symptoms were differentially associated with core network connectivity and emotion dysregulation behaviors in a large group of trauma-exposed refugees.

METHOD

A final sample of 77 trauma-exposed participants completed a rsfMRI scan. Independent component analysis identified active networks and functional network connectivity (FNC) between networks was assessed. Fear and dysphoria posttraumatic symptoms were partially correlated with FNCs, and linear regression models examined relationships with self-reported difficulties in emotion regulation.

RESULTS

Twenty-three active networks were identified, eight being in the networks of interest (p < .05 false discovery rate-corrected). Fear and dysphoria symptoms were specifically related to connectivity patterns between two subnetworks of the default mode network (DMN). Fear symptoms were negatively associated with anterior dorsomedial DMN (admDMN) and temporoparietal DMN (tpDMN) connectivity; whereas dysphoria symptoms were positively associated with admDMN-tpDMN connectivity. Additionally, admDMN-tpDMN connectivity was positively predicted by goal-directed emotion dysregulation but negatively predicted by poor emotional clarity.

CONCLUSIONS

Fear and dysphoria posttraumatic symptoms showed opponent associations with admDMN and tpDMN connectivity, potentially reflecting patterns of under- and overemotion dysregulation associated with these symptom profiles respectively. Findings highlight the importance of considering posttraumatic heterogeneity when constructing neural models of PTSD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Refugee visa insecurity disrupts the brain's default mode network

BACKGROUND

Research has largely focused on the psychological consequences of refugee trauma exposure, but refugees living with visa insecurity face an uncertain future that also adversely affects psychological functioning and self-determination.

OBJECTIVE

This study aimed to examine how refugee visa insecurity affects the functional brain.

METHOD

We measured resting state brain activity via fMRI in 47 refugees with insecure visas (i.e. temporary visa status) and 52 refugees with secure visas (i.e. permanent visa status) residing in Australia, matched on key demographic, trauma exposure and psychopathology. Data analysis comprised independent components analysis to identify active networks and dynamic functional causal modelling tested visa security group differences in network connectivity.

RESULTS

We found that visa insecurity specifically affected sub-systems within the default mode network (DMN) - an intrinsic network subserving self-referential processes and mental simulations about the future. The insecure visa group showed less spectral power in the low frequency band in the anterior ventromedial DMN, and reduced activity in the posterior frontal DMN, compared to the secure visa group. Using functional dynamic causal modelling, we observed positive coupling between the anterior and posterior midline DMN hubs in the secure visa group, while the insecure visa group displayed negative coupling that correlated with self-reported fear of future deportation.

CONCLUSIONS

Living with visa-related uncertainty appears to undermine synchrony between anterior-posterior midline components of the DMN responsible for governing the construction of the self and making mental representations of the future. This could represent a neural signature of refugee visa insecurity, which is marked by a perception of living in limbo and a truncated sense of the future.

The impact of torture on interpersonal threat and reward neurocircuitry

OBJECTIVE

Torture adversely influences emotional functioning, but the neurophysiological mechanisms underpinning its impact are unknown. This study examined how torture exposure affects the neural substrates of interpersonal threat and reward processing.

METHODS

Male refugees with (N = 31) and without (N = 27) torture exposure completed a clinical interview and functional magnetic resonance imaging scan where they viewed fear, happy and neutral faces. Between-group activations and neural coupling were examined as moderated by posttraumatic stress disorder symptom severity and cumulative trauma load.

RESULTS

Posttraumatic stress disorder symptom severity and trauma load significantly moderated group differences in brain activation and connectivity patterns. Torture survivors deactivated the ventral striatum during happy processing compared to non-torture survivor controls as a function of increased posttraumatic stress disorder symptom severity - particularly avoidance symptoms. The ventral striatum was more strongly coupled with the inferior frontal gyrus in torture survivors. Torture survivors also showed left hippocampal deactivation to both fear and happy faces, moderated by trauma load, compared to controls. Stronger coupling between the hippocampus and frontal, temporoparietal and subcortical regions during fear processing was observed, with pathways being predicted by avoidance and hyperarousal symptoms.

CONCLUSION

Torture exposure was associated with distinct brain activity and connectivity patterns during threat and reward processing, dependent on trauma exposure and posttraumatic stress disorder symptom severity. Torture appears to affect emotional brain functioning, and findings have the potential to guide more targeted interventions for torture survivors.

Complex Posttraumatic Stress Disorder Symptom Profiles in Traumatized Refugees

Although it is well documented that exposure to severe, cumulative trauma and postdisplacement stress increases the risk for posttraumatic stress symptom disorder (PTSD), less is known about the representation and predictors of complex PTSD (CPTSD) symptoms in refugee populations. We examined PTSD and CPTSD symptom profiles (co-occurring PTSD and disturbances in self-organization [DSO] symptoms) and their premigration, postmigration, and demographic predictors, using latent class analysis (LCA), in a cohort of 112 refugees resettled in Australia. The LCA identified a four-factor model as the best fit to the data, comprising classes categorized as: (a) CPTSD, exhibiting high levels of PTSD and DSO symptoms (29.5%); (b) PTSD only (23.5%); (c) high affective dysregulation (AD) symptoms (31.9%); and (d) low PTSD and DSO symptoms (15.1%). Membership in the CPTSD and PTSD classes was specifically associated with cumulative traumatization, CPTSD OR = 1.56, 95% CI [1.15, 2.12], and PTSD OR = 1.64, 95% CI [1.15, 2.34]; and female gender, CPTSD OR = 14.18, 95% CI [1.66, 121.29], and PTSD OR = 16.84, 95% CI [1.78, 159.2], relative to the low-symptom class. Moreover, CPTSD and AD class membership was significantly predicted by insecure visa status, CPTSD OR = 7.53, 95% CI [1.26, 45.08], and AD OR = 7.19, 95% CI [1.23, 42.05]. These findings are consistent with the ICD-11 model of CPTSD and highlight the contributions of cumulative trauma to CPTSD and PTSD profiles as well as of contextual stress from visa uncertainty to DSO symptom profiles in refugee cohorts, particularly those characterized by AD.

A new glucose-6-phosphate dehydrogenase variant G6PD Sugao (826C-->T) exhibiting chronic hemolytic anemia with episodes of hemolytic crisis immediately after birth

A case of glucose-6-phosphate dehydrogenase (G6PD) deficiency associated with chronic hemolysis with episodes of hemolytic crisis immediately after birth is reported. The propositus was a 1-month-old Japanese male infant. Molecular analysis of the G6PD gene revealed a novel missense mutation (826C-->4T) in exon 8 predicting a single amino acid substitution, Pro276Ser. The mother was confirmed to be heterozygous for this mutation. We designated this novel class 1 variant as G6PD Sugao. Pro276 is a phylogenetically conserved residue that may play a significant role in dimer formation.

Space radiation enhancement linked to geomagnetic disturbances

Space radiation dosimetry measurements have been made on board the Space Shuttle. A newly developed active detector called "Real-time Radiation Monitoring Device (RRMD)" was used (Doke et al., 1995; Hayashi et al., 1995). The RRMD results indicate that low Linear Energy Transfer (LET) particles steadily penetrate around the South Atlantic Anomaly (SAA) without clear enhancement of dose equivalent and some daily periodic enhancements of dose equivalent due to high LET particles are seen at the lower geomagnetic cutoff regions (Doke et al., 1996). We also have been analyzing the space weather during the experiment, and found that the anomalous high-energy particle enhancement was linked to geomagnetic disturbance due to the high speed solar wind from a coronal hole. Additional analysis and other experiments are necessary for clarification of these phenomena. If a penetration of high-energy particles into the low altitude occurs by common geomagnetic disturbances, the prediction of geomagnetic activity becomes more important in the next Space Station's era.

Space radiation enhancement linked to geomagnetic disturbances

Space radiation dosimetry measurements have been made on board the Space Shuttle. A newly developed active detector called "Real-time Radiation Monitoring Device (RRMD)" was used (Doke et al., 1995; Hayashi et al., 1995). The RRMD results indicate that low Linear Energy Transfer (LET) particles steadily penetrate around the South Atlantic Anomaly (SAA) without clear enhancement of dose equivalent and some daily periodic enhancements of dose equivalent due to high LET particles are seen at the lower geomagnetic cutoff regions (Doke et al., 1996). We also have been analyzing the space weather during the experiment, and found that the anomalous high-energy particle enhancement was linked to geomagnetic disturbance due to the high speed solar wind from a coronal hole. Additional analysis and other experiments are necessary for clarification of these phenomena. If a penetration of high-energy particles into the low altitude occurs by common geomagnetic disturbances, the prediction of geomagnetic activity becomes more important in the next Space Station's era.

Petechial glove and sock syndrome caused by parvovirus B19

The petechial glove and sock syndrome is a recently described febrile dermatosis characterized by acral pruritus, edema, pain, petechiae, and an enanthem of petechiae and erosions; these features suggest a viral origin. We report a typical case in a 36-year-old woman. IgM antibodies to human parvovirus B19 (PVB19) were present, and acute and convalescent IgG antibodies demonstrated seroconversion, which suggested recent infection with PVB19. Results of tests for other viral and bacterial agents were negative. These results strongly implicate PVB19 as an etiologic agent in the petechial glove and sock syndrome.