Association between Individual versus Community-level Social Vulnerability and Neonatal Opioid Withdrawal Syndrome among Pregnant Individuals Receiving Buprenorphine for Opioid Use Disorder.

OBJECTIVE: Individual patient-level measures of adverse social determinants of health are associated with neonatal opioid withdrawal syndrome (NOWS), but the relative impact of community-level adverse social determinants of health remains to be defined. We examined the association between community-level social vulnerability and NOWS among pregnant individuals receiving buprenorphine for opioid use disorder. STUDY DESIGN: We conducted a secondary analysis of an established cohort of pregnant individuals and their infants participating in a multidisciplinary prenatal/addiction care program from 2013 to 2021. Addresses were geocoded using ArcGIS and linked at the census tract to the Centers for Disease Control and Prevention 2018 Social Vulnerability Index (SVI), incorporating 15 census variables. The primary exposure was the SVI as a composite measure of community-level social vulnerability, and secondarily, individual scores for four thematic domains (socioeconomic status, household composition and disability, minority status and language, and housing type and transportation). The primary outcome was a clinical diagnosis of NOWS defined as withdrawal requiring pharmacological treatment following buprenorphine exposure. RESULTS: Among 703 pregnant individuals receiving buprenorphine, 39.8% (280/703) of infants were diagnosed with NOWS. Among our patinets, those who were nulliparous, had post-traumatic stress disorder, a term birth (≥ 37 weeks) and had a male infant were more likely to have an infant diagnosed with NOWS. Individuals with and without an infant diagnosed with NOWS had similarly high community-level social vulnerability per composite SVI scores (mean [standard deviation]: 0.6 [0.4-0.7] vs. 0.6 [0.4-0.7], p = 0.2]. In adjusted analyses, SVI, as a composite measure as well as the four domains, was not associated with NOWS diagnosis. CONCLUSION: Among pregnant persons receiving buprenorphine enrolled in a multidisciplinary prenatal and addition care program, while individual risk factors that measure adverse social determinants of health were associated with an NOWS diagnosis in the infant, community-level social vulnerability as measured by the SVI was not associated with the outcome. KEY POINTS: · Community-level SVI was not associated with neonatal opioid use disorder.. · Certain individual risk factors were identified as being associated with NOWS.. · Homogeneity of composite SVI scores may have led to lack of significant findings..

Lateralized memory circuit dropout in Alzheimer's disease patients.

Altered connectivity within neuronal networks is often observed in Alzheimer's disease. However, delineating pro-cognitive compensatory changes from pathological network decline relies on characterizing network and task effects together. In this study, we interrogated the dynamics of occipito-temporo-frontal brain networks responsible for implicit and explicit memory processes using high-density EEG and dynamic causal modelling. We examined source-localized network activity from patients with Alzheimer's disease (n = 21) and healthy controls (n = 21), while they performed both visual recognition (explicit memory) and implicit priming tasks. Parametric empirical Bayes analyses identified significant reductions in temporo-frontal connectivity and in subcortical visual input in patients, specifically in the left hemisphere during the recognition task. There was also slowing in frontal left hemisphere signal transmission during the implicit priming task, with significantly more distinct dropout in connectivity during the recognition task, suggesting that these network drop-out effects are affected by task difficulty. Furthermore, during the implicit memory task, increased right frontal activity was correlated with improved task performance in patients only, suggesting that right-hemisphere compensatory mechanisms may be employed to mitigate left-lateralized network dropout in Alzheimer's disease. Taken together, these findings suggest that Alzheimer's disease is associated with lateralized memory circuit dropout and potential compensation from the right hemisphere, at least for simpler memory tasks.

Aging into Perceptual Control: A Dynamic Causal Modeling for fMRI Study of Bistable Perception.

Aging is accompanied by stereotyped changes in functional brain activations, for example a cortical shift in activity patterns from posterior to anterior regions is one hallmark revealed by functional magnetic resonance imaging (fMRI) of aging cognition. Whether these neuronal effects of aging could potentially contribute to an amelioration of or resistance to the cognitive symptoms associated with psychopathology remains to be explored. We used a visual illusion paradigm to address whether aging affects the cortical control of perceptual beliefs and biases. Our aim was to understand the effective connectivity associated with volitional control of ambiguous visual stimuli and to test whether greater top-down control of early visual networks emerged with advancing age. Using a bias training paradigm for ambiguous images we found that older participants (n = 16) resisted experimenter-induced visual bias compared to a younger cohort (n = 14) and that this resistance was associated with greater activity in prefrontal and temporal cortices. By applying Dynamic Causal Models for fMRI we uncovered a selective recruitment of top-down connections from the middle temporal to Lingual gyrus (LIN) by the older cohort during the perceptual switch decision following bias training. In contrast, our younger cohort did not exhibit any consistent connectivity effects but instead showed a loss of driving inputs to orbitofrontal sources following training. These findings suggest that perceptual beliefs are more readily controlled by top-down strategies in older adults and introduce age-dependent neural mechanisms that may be important for understanding aberrant belief states associated with psychopathology.

Altered Prefrontal Excitation/Inhibition Balance and Prefrontal Output: Markers of Aging in Human Memory Networks.

Memory impairments and heightened prefrontal cortical (PFC) activity are hallmarks of cognitive and neurobiological human aging. While structural integrity of PFC gray matter and interregional white matter tracts are thought to impact memory processing, the balance of neurotransmitters within the PFC itself is less well understood. We used fMRI to establish whole-brain networks involved in a memory encoding task and dynamic causal models (DCMs) for fMRI to determine the causal relationships between these areas. These data revealed enhanced connectivity from PFC to medial temporal cortex that negatively correlated with recall ability. To better understand the intrinsic activity within the PFC, DCM for EEG was employed after continuous theta burst transcranial magnetic stimulation (TMS) to the PFC to assess the effect on excitatory/inhibitory (E/I) synaptic ratios and behavior. These data revealed that the young cohort had a stable E/I ratio that was unaffected by the TMS intervention, while the aged cohort exhibited lower E/I ratios driven by a greater intrinsic inhibitory tone. TMS to the aged cohort resulted in decreased intrinsic inhibition and a decrement in memory performance. These results demonstrate increased top-down influence of PFC upon medial temporal lobe in healthy aging that is associated with decreased memory and may be due to unstable local inhibitory tone within the PFC.