Aberrant Connections Research Articles

Alternations voxel-wise interhemispheric and intrahemipheric functional connectivity dynamics in internet gaming disorder

BackgroundCurrently, numerous studies have indicated that individuals with internet gaming disorder (IGDs) have aberrant functional connection patterns between multiple brain regions and networks. However, temporal variability in the intra- and interhemispheric dynamic functional connectivity in IGDs remains unknown. MethodsThis study investigated resting-state functional magnetic resonance data from 55 IGDs and 50 demographically matched healthy controls (HCs). Functional connectivity density (FCD) combined with sliding window analysis is employed to calculate the temporal variability of global functional connectivity. The temporal variability of dynamic functional connectivity further quantified utilizing the standard deviations of global, intra-, and interhemispheric FCD. Finally, correlation analyses were performed between dynamic FCD varience (dFCD) in differential brain regions and clinical behaviors. ResultIGDs showed decreased intra- and interhemispheric dFCD variance in the visual attention network (precuneus and calcarine) and also demonstrated hemispheric-level dFCD variance abnormalities in the posterior cingulate cortex (PCC) compared to HCs. Moreover, abnormal global dFCD variability of the calcarine and ipsilateral dFCD variability of the PCC were negatively correlated with the severity of IGDs in the IGD group. ConclusionOur results demonstrate abberant intra- and interhemispheric dynamic functional connectivity in the visual attention network, which emphasizes the neurobiological basis for impaired concentration in IGDs.

Abnormal individualized functional connectivity: A potential stimulation target for pediatric tourette syndrome

ObjectiveIn order to examine whether individualized peak functional connectivity could potentially serve as a target for repetitive transcranial magnetic stimulation (rTMS) therapy, we investigated the location of peak functional connectivity (FC) between the cortical motor area and the key brain region, the globus pallidus internus (GPi), in Tourette syndrome, and explored the relationship between the severity of the disease and these aberrant functional connections. MethodsThe study involved a cohort of 103 children diagnosed with Tourette syndrome and 66 age-matched typically developing children. The GPi was served as the seed, and the study compared individualized peak FC strength in the supplementary motor area (SMA) and premotor area between the two groups. Spatial distribution of peak FC in the motor area and GPi-based voxel-wise FC were also analyzed. ResultsChildren with Tourette syndrome exhibited lower peak FC in the left SMA when using left GPi as the seed. This reduction in peak FC demonstrated a significant and negative correlation with the Yale Global Tic Severity Scale scores. ConclusionsSMA-GPi FC is one of the key pathological circuit in Tourette syndrome. SignificanceThe individual peak FC location in the left SMA potentially serve as stimulation targets for rTMS treatment of TS.

Brain plasticity following lumbar disc herniation treatment with spinal manipulation therapy based on resting-state functional magnetic resonance imaging

As a prevalent spine disorder, Lumbar disc herniation (LDH) has been affecting more than 2 % of the worldwide population and is characterised by uncertain causes and recurring episodes. Studying the brain activity of patients could potentially provide insights into its pathogenesis and significantly enhance therapy. Therefore, we here examined brain function in patients under Spinal Manipulative Therapy (SMT). By analysing regional homogeneity (ReHo) at different frequency bands, we identified the discrepancies in brain activity between LDH patients and healthy people, highlighting the frequency dependence of spontaneous low-frequency oscillations among patients with LDH. Choosing seeds based on the peak ReHo differences helped to elucidate the functional connectivity alterations in the brain regions of LDH. Overall, this study showed that SMT significantly reduced pain, improved dysfunction, and partially rectified aberrant local consistency and functional connection in patients with LDH, not only offering insights into the pathophysiology of LDH from a neurological standpoint, but also providing inspiration for the development of new therapies based on neurobiology.

Characterizing white matter connectome abnormalities in patients with temporal lobe epilepsy using threshold-free network-based statistics.

Emerging evidence illustrates that temporal lobe epilepsy (TLE) involves network disruptions represented by hyperexcitability and other seizure-related neural plasticity. However, these associations are not well-characterized. Our study characterizes the whole brain white matter connectome abnormalities in TLE patients compared to healthy controls (HCs) from the prospective Epilepsy Connectome Project study. Furthermore, we assessed whether aberrant white matter connections are differentially related to cognitive impairment and a history of focal-to-bilateral tonic-clonic (FBTC) seizures. Multi-shell connectome MRI data were preprocessed using the DESIGNER guidelines. The IIT Destrieux gray matter atlas was used to derive the 162×162 structural connectivity matrices (SCMs) using MRTrix3. ComBat data harmonization was applied to harmonize the SCMs from pre- and post-scanner upgrade acquisitions. Threshold-free network-based statistics were used for statistical analysis of the harmonized SCMs. Cognitive impairment status and FBTC seizure status were then correlated with these findings. We employed connectome measurements from 142 subjects, including 92 patients with TLE (36 males, mean age=40.1±11.7 years) and 50 HCs (25 males, mean age=32.6±10.2 years). Our analysis revealed overall significant decreases in cross-sectional area (CSA) of the white matter tract in TLE group compared to controls, indicating decreased white matter tract integrity and connectivity abnormalities in addition to apparent differences in graph theoretic measures of connectivity and network-based statistics. Focal and generalized cognitive impaired TLE patients showcased higher trend-level abnormalities in the white matter connectome via decreased CSA than those with no cognitive impairment. Patients with a positive FBTC seizure history also showed trend-level findings of association via decreased CSA. Widespread global aberrant white matter connectome changes were observed in TLE patients and characterized by seizure history and cognitive impairment, laying a foundation for future studies to expand on and validate the novel biomarkers and further elucidate TLE's impact on brain plasticity.

Between neurons and networks: investigating mesoscale brain connectivity in neurological and psychiatric disorders.

The study of brain connectivity has been a cornerstone in understanding the complexities of neurological and psychiatric disorders. It has provided invaluable insights into the functional architecture of the brain and how it is perturbed in disorders. However, a persistent challenge has been achieving the proper spatial resolution, and developing computational algorithms to address biological questions at the multi-cellular level, a scale often referred to as the mesoscale. Historically, neuroimaging studies of brain connectivity have predominantly focused on the macroscale, providing insights into inter-regional brain connections but often falling short of resolving the intricacies of neural circuitry at the cellular or mesoscale level. This limitation has hindered our ability to fully comprehend the underlying mechanisms of neurological and psychiatric disorders and to develop targeted interventions. In light of this issue, our review manuscript seeks to bridge this critical gap by delving into the domain of mesoscale neuroimaging. We aim to provide a comprehensive overview of conditions affected by aberrant neural connections, image acquisition techniques, feature extraction, and data analysis methods that are specifically tailored to the mesoscale. We further delineate the potential of brain connectivity research to elucidate complex biological questions, with a particular focus on schizophrenia and epilepsy. This review encompasses topics such as dendritic spine quantification, single neuron morphology, and brain region connectivity. We aim to showcase the applicability and significance of mesoscale neuroimaging techniques in the field of neuroscience, highlighting their potential for gaining insights into the complexities of neurological and psychiatric disorders.

The role of GPRASP1 mutations in the pathogenesis of arteriovenous malformations

Arteriovenous Malformation (AVM) is a sporadic vascular disease caused by the aberrant direct connection between arterioles and veins, resulting in disorganized blood shunting and oxygen level disparities. Previous research has elucidated some of the genetic underpinnings of AVM and related vascular anomalies. Despite its significant prevalence, current therapeutic approaches remain largely conservative, underscoring the need for a deeper understanding of AVM pathogenesis. This study focuses on the GPRASP1 gene, which encodes the G-protein coupled receptor-associated sorting protein 1 (GASP-1), a molecule implicated in vascular development. Utilizing western blotting and cellular assays, we explored the role of GPRASP1 in angiogenesis, neoplastic formation, and other mechanical aspects of AVM. Our findings suggested that mutations in the GPRASP1 gene may contribute to elevated levels of angiogenic factors and altered cellular functions related to angiogenesis, such as enhanced proliferative and migratory capabilities. This research lays the groundwork for identifying novel therapeutic targets in the management of AVM and offers insights into precision medicine approaches.

Dynamic functional network connectivity analysis in schizophrenia based on a spatiotemporal CPD framework.

Objective.Dynamic functional network connectivity (dFNC), based on data-driven group independent component (IC) analysis, is an important avenue for investigating underlying patterns of certain brain diseases such as schizophrenia. Canonical polyadic decomposition (CPD) of a higher-way dynamic functional connectivity tensor, can offer an innovative spatiotemporal framework to accurately characterize potential dynamic spatial and temporal fluctuations. Since multi-subject dFNC data from sliding-window analysis are also naturally a higher-order tensor, we propose an innovative sparse and low-rank CPD (SLRCPD) for the three-way dFNC tensor to excavate significant dynamic spatiotemporal aberrant changes in schizophrenia.Approach.The proposed SLRCPD approach imposes two constraints. First, the L1regularization on spatial modules is applied to extract sparse but significant dynamic connectivity and avoid overfitting the model. Second, low-rank constraint is added on time-varying weights to enhance the temporal state clustering quality. Shared dynamic spatial modules, group-specific dynamic spatial modules and time-varying weights can be extracted by SLRCPD. The strength of connections within- and between-IC networks and connection contribution are proposed to inspect the spatial modules. K-means clustering and classification are further conducted to explore temporal group difference.Main results.82 subject resting-state functional magnetic resonance imaging (fMRI) dataset and opening Center for Biomedical Research Excellence (COBRE) schizophrenia dataset both containing schizophrenia patients (SZs) and healthy controls (HCs) were utilized in our work. Three typical dFNC patterns between different brain functional regions were obtained. Compared to the spatial modules of HCs, the aberrant connections among auditory network, somatomotor, visual, cognitive control and cerebellar networks in 82 subject dataset and COBRE dataset were detected. Four temporal states reveal significant differences between SZs and HCs for these two datasets. Additionally, the accuracy values for SZs and HCs classification based on time-varying weights are larger than 0.96.Significance.This study significantly excavates spatio-temporal patterns for schizophrenia disease.

Multi feature fusion network for schizophrenia classification and abnormal brain network recognition

Schizophrenia classification and abnormal brain network recognition have an important research significance. Researchers have proposed many classification methods based on machine learning and deep learning. However, fewer studies utilized the advantages of complementary information from multi feature to learn the best representation of schizophrenia. In this study, we proposed a multi-feature fusion network (MFFN) using functional network connectivity (FNC) and time courses (TC) to distinguish schizophrenia patients from healthy controls. DNN backbone was adopted to learn the feature map of functional network connectivity, C-RNNAM backbone was designed to learn the feature map of time courses, and Deep SHAP was applied to obtain the most discriminative brain networks. We proved the effectiveness of this proposed model using the combining two public datasets and evaluated this model quantitatively using the evaluation indexes. The results showed that the functional network connectivity generated by independent component analysis has advantage in schizophrenia classification by comparing static and dynamic functional connections. This method obtained the best classification accuracy (ACC=87.30%, SPE=89.28%, SEN=85.71%, F1 =88.23%, and AUC=0.9081), and it demonstrated the superiority of this proposed model by comparing state-of-the-art methods. Ablation experiment also demonstrated that multi feature fusion and attention module can improve classification accuracy. The most discriminative brain networks showed that default mode network and visual network of schizophrenia patients have aberrant connections in brain networks. In conclusion, this method can identify schizophrenia effectively and visualize the abnormal brain network, and it has important clinical application value.

Investigating altered brain functional hubs and causal connectivity in coronary artery disease with cognitive impairment.

Coronary artery disease (CAD) and cognitive impairment (CI) have become significant global disease and medical burdens. There have been several reports documenting the alterations in regional brain function and their correlation with CI in CAD patients. However, there is limited research on the changes in brain network connectivity in CAD patients. To investigate the resting-state connectivity and further understand the effective connectivity strength and directionality in patients with CAD, we utilized degree centrality (DC) and spectral dynamic causal modeling (spDCM) to detect functional hubs in the whole brain network, followed by an analysis of directional connections. Using the aforementioned approaches, it is possible to investigate the hub regions and aberrant connections underlying the altered brain function in CAD patients, providing neuroimaging evidence for the cognitive decline in patients with coronary artery disease. This study was prospectively conducted involving 24 patients diagnosed with CAD and 24 healthy controls (HC) who were matched in terms of age, gender, and education. Functional MRI (fMRI) scans were utilized to investigate brain activity in these individuals. Neuropsychological examinations were performed on all participants. DC analysis and spDCM were employed to investigate abnormal brain networks in patients with CAD. Additionally, the association between effective connectivity strength and cognitive function in patients with CAD was examined based on the aforementioned results. By assessing cognitive functions, we discovered that patients with CAD exhibited notably lower cognitive function compared to the HC group. By utilizing DC analysis and spDCM, we observed significant reductions in DC values within the left parahippocampal cortex (PHC) and the left medial temporal gyrus (MTG) in CAD patients when compared to the control group. In terms of effective connectivity, we observed the absence of positive connectivity between the right superior frontal gyrus (SFG) and PHC in CAD patients. Moreover, there was an increase in negative connectivity from PHC and MTG to SFG, along with a decrease in the strength of positive connectivity between PHC and MTG. Furthermore, we identified a noteworthy positive correlation (r = 0.491, p = 0.015) between the strength of connectivity between the PHC and the MTG and cognitive function in CAD patients. These research findings suggest that alterations in the connectivity of the brain networks involving SFG, PHC, and MTG in CAD patients may mediate changes in cognitive function.

Cholecystoduodenal fistula: An incidental finding of gall stone disease in a young male

Abstract Chronic calculous cholecystitis, if left untreated for a long time, can lead to a bilioenteric fistula, which is an aberrant connection between the bile duct system and the gastrointestinal tract. These fistulas have a variety of clinical manifestations and may risk the patient’s life. Hence, the authors report a rare case of a patient presenting with a cholecystoduodenal fistula.

Neuroimaging Study of Brain Functional Differences in Generalized Anxiety Disorder and Depressive Disorder.

Generalized anxiety disorder (GAD) and depressive disorder (DD) are distinct mental disorders, which are characterized by complex and unique neuroelectrophysiological mechanisms in psychiatric neurosciences. The understanding of the brain functional differences between GAD and DD is crucial for the accurate diagnosis and clinical efficacy evaluation. The aim of this study was to reveal the differences in functional brain imaging between GAD and DD based on multidimensional electroencephalogram (EEG) characteristics. To this end, 10 min resting-state EEG signals were recorded from 38 GAD and 34 DD individuals. Multidimensional EEG features were subsequently extracted, which include power spectrum density (PSD), fuzzy entropy (FE), and phase lag index (PLI). Then, a direct statistical analysis (i.e., ANOVA) and three ensemble learning models (i.e., Random Forest (RF), Light Gradient Boosting Machine (LightGBM), eXtreme Gradient Boosting (XGBoost)) were used on these EEG features for the differential recognitions. Our results showed that DD has significantly higher PSD values in the alpha1 and beta band, and a higher FE in the beta band, in comparison with GAD, along with the aberrant functional connections in all four bands between GAD and DD. Moreover, machine learning analysis further revealed that the distinct features predominantly occurred in the beta band and functional connections. Here, we show that DD has higher power and more complex brain activity patterns in the beta band and reorganized brain functional network structures in all bands compared to GAD. In sum, these findings move towards the practical identification of brain functional differences between GAD and DD.

A prospective study on enterocutaneous fistula in a tertiary care centre: A single institution study

Background: Aberrant connection linking gastrointestinal tract and the skin is termed Enterocutaneous fistula. Enterocutaneous fistulas can lead to significant morbidity and mortality. Death pertaining to enterocutaneous fistulas remains enormous when juxtaposed with other surgeries. The treatment of Enterocutaneous fistula may be a significant challenge to surgeons and gastroenterologists. Method: After obtaining ethical committee clearance, a total of 25 patients of Enterocutaneous fistula who presented to Surgical department and Surgical Gastroenterology department were included in the study. The cause, site and output of fistula, clinical course and complications of fistula were studied. Patients were managed either surgically or conservatively depending on the output of the fistula, nutrition and metabolic profile. Results: 19 patients were managed conservatively and 6 patients were managed surgically. Amidst the conservative group, 16 out of 19 patients had spontaneous closure of fistula and remaining three had died as fistulas failed to close. Surgical closure was accomplished in 5 patients but failed in one patient and that patient died. 96% (24 out of 25) of patients in our study had developed fistula post operatively. Among 25 patients studied, nearly 44% each i.e., 11 out of 25 patients had colonic and small bowel fistula respectively followed by fistula at appendix accounting for 12% (i.e., Fistula Output: 11 (44%) fistulae were low output, 8 (32%) were medium output. Conclusion: Enterocutaneous fistulas are more common in postoperative period. Conservative treatment should be the mainstay in management of Enterocutaneous fistula.

Task-residual effective connectivity of motor network in transient ischemic attack

Transient ischemic attack (TIA) is a temporary episode of neurological dysfunction that results from focal brain ischemia. Although TIA symptoms are quickly resolved, patients with TIA have a high risk of stroke and persistent impairments in multiple domains of cognitive and motor functions. In this study, using spectral dynamic causal modeling, we investigate the changes in task-residual effective connectivity of patients with TIA during fist-closing movements. 28 healthy participants and 15 age-matched patients with TIA undergo functional magnetic resonance imaging at 7T. Here we show that during visually cued motor movement, patients with TIA have significantly higher effective connectivity toward the ipsilateral primary motor cortex and lower connectivity to the supplementary motor area than healthy controls. Our results imply that TIA patients have aberrant connections among motor regions, and these changes may reflect the decreased efficiency of primary motor function and disrupted control of voluntary movement in patients with TIA.

Neuroanatomical Alterations in the CNTNAP2 Mouse Model of Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is associated with neurodevelopmental alterations, including atypical forebrain cellular organization. Mutations in several ASD-related genes often result in cerebral cortical anomalies, such as the abnormal developmental migration of excitatory pyramidal cells and the malformation of inhibitory neuronal circuitry. Notably here, mutations in the CNTNAP2 gene result in ectopic superficial cortical neurons stalled in lower cortical layers and alterations to the balance of cortical excitation and inhibition. However, the broader circuit-level implications of these findings have not been previously investigated. Therefore, we assessed whether ectopic cortical neurons in CNTNAP2 mutant mice form aberrant connections with higher-order thalamic nuclei, potentially accounting for some autistic behaviors, such as repetitive and hyperactive behaviors. Furthermore, we assessed whether the development of parvalbumin-positive (PV) cortical interneurons and their specialized matrix support structures, called perineuronal nets (PNNs), were altered in these mutant mice. We found alterations in both ectopic neuronal connectivity and in the development of PNNs, PV neurons and PNNs enwrapping PV neurons in various sensory cortical regions and at different postnatal ages in the CNTNAP2 mutant mice, which likely lead to some of the cortical excitation/inhibition (E/I) imbalance associated with ASD. These findings suggest neuroanatomical alterations in cortical regions that underlie the emergence of ASD-related behaviors in this mouse model of the disorder.

Ogt Deficiency Induces Abnormal Cerebellar Function and Behavioral Deficits of Adult Mice through Modulating RhoA/ROCK Signaling.

Previous studies have shown the essential roles of O-GlcNAc transferase (Ogt) and O-GlcNAcylation in neuronal development, function and neurologic diseases. However, the function of Ogt and O-GlcNAcylation in the adult cerebellum has not been well elucidated. Here, we have found that cerebellum has the highest level of O-GlcNAcylation relative to cortex and hippocampus of adult male mice. Specific deletion of Ogt in granule neuron precursors (GNPs) induces abnormal morphology and decreased size of the cerebellum in adult male Ogt deficient [conditional knock-out (cKO)] mice. Adult male cKO mice show the reduced density and aberrant distribution of cerebellar granule cells (CGCs), the disrupted arrangement of Bergman glia (BG) and Purkinje cells. In addition, adult male cKO mice exhibit aberrant synaptic connection, impaired motor coordination, and learning and memory abilities. Mechanistically, we have identified G-protein subunit α12 (Gα12) is modified by Ogt-mediated O-GlcNAcylation. O-GlcNAcylation of Gα12 facilitates its binding to Rho guanine nucleotide exchange factor 12 (Arhgef12) and consequently activates RhoA/ROCK signaling. RhoA/ROCK pathway activator LPA can rescue the developmental deficits of Ogt deficient CGCs. Therefore, our study has revealed the critical function and related mechanisms of Ogt and O-GlcNAcylation in the cerebellum of adult male mice.SIGNIFICANCE STATEMENT Cerebellar function are regulated by diverse mechanisms. To unveil novel mechanisms is critical for understanding the cerebellar function and the clinical therapy of cerebellum-related diseases. In the present study, we have shown that O-GlcNAc transferase gene (Ogt) deletion induces abnormal cerebellar morphology, synaptic connection, and behavioral deficits of adult male mice. Mechanistically, Ogt catalyzes O-GlcNAcylation of Gα12, which promotes the binding to Arhgef12, and regulates RhoA/ROCK signaling pathway. Our study has uncovered the important roles of Ogt and O-GlcNAcylation in regulating cerebellar function and cerebellum-related behavior. Our results suggest that Ogt and O-GlcNAcylation could be potential targets for some cerebellum-related diseases.

Aberrant Large-Scale Network Interactions Across Psychiatric Disorders Revealed by Large-Sample Multi-Site Resting-State Functional Magnetic Resonance Imaging Datasets.

Dynamics of the distributed sets of functionally synchronized brain regions, known as large-scale networks, are essential for the emotional state and cognitive processes. However, few studies were performed to elucidate the aberrant dynamics across the large-scale networks across multiple psychiatric disorders. In this paper, we aimed to investigate dynamic aspects of the aberrancy of the causal connections among the large-scale networks of the multiple psychiatric disorders. We applied dynamic causal modeling (DCM) to the large-sample multi-site dataset with 739 participants from 4 imaging sites including 4 different groups, healthy controls, schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BD), to compare the causal relationships among the large-scale networks, including visual network, somatomotor network (SMN), dorsal attention network (DAN), salience network (SAN), limbic network (LIN), frontoparietal network, and default mode network. DCM showed that the decreased self-inhibitory connection of LIN was the common aberrant connection pattern across psychiatry disorders. Furthermore, increased causal connections from LIN to multiple networks, aberrant self-inhibitory connections of DAN and SMN, and increased self-inhibitory connection of SAN were disorder-specific patterns for SCZ, MDD, and BD, respectively. DCM revealed that LIN was the core abnormal network common to psychiatric disorders. Furthermore, DCM showed disorder-specific abnormal patterns of causal connections across the 7 networks. Our findings suggested that aberrant dynamics among the large-scale networks could be a key biomarker for these transdiagnostic psychiatric disorders.

Disorganization of Semantic Brain Networks in Schizophrenia Revealed by fMRI.

Schizophrenia is a mental illness that presents with thought disorders including delusions and disorganized speech. Thought disorders have been regarded as a consequence of the loosening of associations between semantic concepts since the term "schizophrenia" was first coined by Bleuler. However, a mechanistic account of this cardinal disturbance in terms of functional dysconnection has been lacking. To evaluate how aberrant semantic connections are expressed through brain activity, we characterized large-scale network structures of concept representations using functional magnetic resonance imaging (fMRI). We quantified various concept representations in patients' brains from fMRI activity evoked by movie scenes using encoding modeling. We then constructed semantic brain networks by evaluating the similarity of these semantic representations and conducted graph theory-based network analyses. Neurotypical networks had small-world properties similar to those of natural languages, suggesting small-worldness as a universal property in semantic knowledge networks. Conversely, small-worldness was significantly reduced in networks of schizophrenia patients and was correlated with psychological measures of delusions. Patients' semantic networks were partitioned into more distinct categories and had more random within-category structures than those of controls. The differences in conceptual representations manifest altered semantic clustering and associative intrusions that underlie thought disorders. This is the first study to provide pathophysiological evidence for the loosening of associations as reflected in randomization of semantic networks in schizophrenia. Our method provides a promising approach for understanding the neural basis of altered or creative inner experiences of individuals with mental illness or exceptional abilities, respectively.

A deceptive mass on neonatal ultrasound and a fetal brain MRI-confirmed complex dural arteriovenous fistula postnatally: illustrative case.

Dural arteriovenous fistulas (dAVFs) are direct, aberrant connections between dural arteries and cerebral veins. In neonates, delayed diagnosis results in grim outcomes. Treatment involves endovascular management because of its success and tolerability. Here, the authors present a case of a complex dAVF initially recognized with an in utero neurosonogram and fetal magnetic resonance imaging (MRI). A 21-week fetal ultrasound of a nonspecific brain mass was confirmed with fetal MRI as a 2.7-cm T1-hyperintense posterior fossa mass. Although a large flow void in the left middle cranial fossa was present, postnatal computed tomography angiography ultimately revealed a high-flow dAVF communicating with the left transverse sinus. In the early postnatal period, the patient developed hydrocephalus. After successful partial embolization, 6-week postangiogram brain MRI indicated disease progression with the development of a venous varix causing brainstem compression. Repeat embolization resulted in complete cessation of early venous drainage. Neonatal dAVFs are exceedingly rare and result in futile outcomes; however, detection in utero is possible. Although definitive therapy must be performed postnatally, constant monitoring and early delivery can prevent complications. Attention to fetal ultrasound is essential, and knowledge of fetal MRI in the detection of these complex lesions can significantly improve outcomes.

High frenal attachment and its prevalence among children - A retrospective study.

The frenum is a narrow mucosa fold surrounded by muscle fibers that connect the lips to the alveolar mucosa and the periosteum beneath. Midline spacing, commonly called as diastema, recession, interference with prosthodontic therapy, and difficulty speaking are all symptoms of a high frenal attachment. Frenectomy is a surgical treatment that involves removing the aberrant frenal connection. The frenum is a connective tissue membrane that connects one mouth surface to the next. The purpose of this study is to see how popular high frenal attachment is among children who visit a university dentistry hospital. This was a retrospective investigation evaluating the prevalence of high frenal attachment in patients visiting a Chennai dental institution. From June 2019 to March 2021, 11278 patients visited a dental clinic.

S3347 The Thirteenth Case of a Congenital Portosystemic Shunt in a Down Syndrome Patient

Introduction: Down syndrome is caused by non-disjunction (Trisomy 21), translocation, or mosaicism at chromosome 21 and is characterized by intellectual disability, dysmorphic facial features, and congenital malformations, including gastrointestinal abnormalities. Congenital portosystemic shunts (CPSS) are rare vascular malformations that form aberrant connections between a portal and systemic vein within the liver, diverting portal flow from the liver to the systemic venous system. The etiology of these malformations is poorly understood. Some hypotheses suggest dysfunction in angiogenic factors, which may play a role in the development of features already seen in Down syndrome, including placental hypo-vascularity, increased fetal nuchal fold thickness, and a tendency to develop pulmonary hypertension. There is an increasing appreciation of congenital portosystemic shunts in Down syndrome patients. Case Description/Methods: Our patient presented with hyperammonemia, altered mental status, and choreiform movements. A computed tomography angiography of the abdomen and pelvis demonstrated a connection between the right portal vein and inferior vena cava, consistent with an intrahepatic congenital portocaval fistula. The lower lungs showed dilated pulmonary artery branches of the peripheral system, suggesting developing hepatopulmonary syndrome (HPS). Interventional radiology placed an 18 mm, Amplatzer PFO closure device within the congenital fistula. No residual flow was seen in the portal vein from the inferior vena cava post-procedure. Clinical improvement was noted following the procedure. His ammonia levels normalized. His mental status returned to baseline with the resolution of choreiform movements. A follow-up abdominal ultrasound demonstrated no residual or recurrent portocaval fistula. At the two-year follow-up, the patient had no recurring issues related to the fistula or closure device placement. Discussion: Herein we describe the third case of a CPSS in a Down Syndrome patient and the 13th overall case of a CPSS with our approach to work up and treatment highlighted in the context of a literature review of similar cases.