17 research outputs found

    MRI Study of Minor Physical Anomaly in Childhood Autism Implicates Aberrant Neurodevelopment in Infancy

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    Background: MPAs (minor physical anomalies) frequently occur in neurodevelopmental disorders because both face and brain are derived from neuroectoderm in the first trimester. Conventionally, MPAs are measured by evaluation of external appearance. Using MRI can help overcome inherent observer bias, facilitate multi-centre data acquisition, and explore how MPAs relate to brain dysmorphology in the same individual. Optical MPAs exhibit a tightly synchronized trajectory through fetal, postnatal and adult life. As head size enlarges with age, inter-orbital distance increases, and is mostly completed before age 3 years. We hypothesized that optical MPAs might afford a retrospective 'window' to early neurodevelopment; specifically, inter-orbital distance increase may represent a biomarker for early brain dysmaturation in autism. Methods: We recruited 91 children aged 7-16; 36 with an autism spectrum disorder and 55 age- and gender-matched typically developing controls. All children had normal IQ. Inter-orbital distance was measured on T1-weighted MRI scans. This value was entered into a voxel-by-voxel linear regression analysis with grey matter segmented from a bimodal MRI data-set. Age and total brain tissue volume were entered as covariates. Results: Intra-class coefficient for measurement of the inter-orbital distance was 0.95. Inter-orbital distance was significantly increased in the autism group (p = 0.03, 2-tailed). The autism group showed a significant relationship between inter-orbital distance grey matter volume of bilateral amygdalae extending to the unci and inferior temporal poles. Conclusions: Greater inter-orbital distance in the autism group compared with healthy controls is consistent with infant head size expansion in autism. Inter-orbital distance positively correlated with volume of medial temporal lobe structures, suggesting a link to "social brain" dysmorphology in the autism group. We suggest these data support the role of optical MPAs as a "fossil record" of early aberrant neurodevelopment, and potential biomarker for brain dysmaturation in autism. © 2011 Cheung et al.published_or_final_versio

    Mapping brain structure in attention deficit-hyperactivity disorder:a voxel-based MRI study of regional grey and white matter volume

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    The neuroanatomical basis of attention deficit-hyperactivity disorder (ADHD) is postulated to involve brain circuitry responsible for attention and executive function. Relatively new automated methods of MRI analysis allow rapid examination of each volume element (voxel) of whole brain, therefore we planned a comprehensive quantitative examination of brain anatomy in children with ADHD using voxel-based methods. We aimed to quantify whole brain, global tissue class and regional grey and white matter volume differences in 28 male children with ADHD and 31 closely matched controls. Since ADHD is often complicated by comorbid oppositional defiant disorder (ODD) and conduct disorder (CD), we also conducted post-hoc analyses of subgroups of children with ADHD with and without these comorbidities. Significant regional deficits in ADHD were observed within a predominantly right-sided frontal-pallidal-parietal grey matter network and bilateral white matter tracts. Post-hoc comparisons suggested that comorbid ODD or CD did not greatly alter the extent of regional pathology in ADHD. The exceptions being cerebellar and striatal volume deficits which were significantly greater in children with ADHD plus comorbidities, but not those with ADHD alone, compared to controls. Overall, restricted structural brain abnormalities caused by ADHD were localized to brain systems known to be necessary for attention and executive function. © 2006 Elsevier Ireland Ltd. All rights reserved.link_to_subscribed_fulltex

    Voxel-wise correlates of inter-orbital distance in autism.

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    <p>Axial view of grey matter brain images. Left of the panel is left hemisphere. Red highlights clusters where inter-orbital distance is positively correlated brain volume in the autism group. Z co-ordinate is given in MNI space.</p

    Measurement of inter-orbital distance in axial and coronal view.

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    <p>Top panel shows coronal view and lower panel shows the axial view. Measurements were made on the coronal view between A and B, with the axial view used for additional reference.</p

    Scatter plot of grey matter volume against inter-orbital distance of a cluster in left and right amygdala region.

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    <p>Inter-orbital distance in mm. Grey matter volume in ml. Autism group represented by triangles and controls by circles. Left amygdala cluster volume correlation with inter-orbital distance is shown in the left panel. Right amygdala cluster correlation is shown in the right panel.</p

    MRI predicts remission at 1 year in first-episode schizophrenia in females with larger striato-thalamic volumes

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    &lt;b&gt;&lt;i&gt;Background/Aims:&lt;/i&gt;&lt;/b&gt; The Remission in Schizophrenia Working Group has defined remission as ‘a low-mild symptom intensity level, maintained for a minimum of 6 months, where such symptoms do not affect an individual's behaviour' [Andreasen et al.: Am J Psychiatry 2005;162:441-449]. Since brain morphology relates to symptomatology, treatment and illness progression, MRI may assist in predicting remission. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; Thirty-nine patients newly diagnosed with DSM-IV schizophrenia underwent MRI brain scan prior to antipsychotic exposure. The Global Assessment of Functioning (GAF) score was entered into a voxel-based analysis to evaluate its relationship with cerebral grey matter volume from the baseline MRI. We entered age, total intracranial volume and intake GAF score as co-variates. Males and females were analysed separately because gender is a potent determinant of outcome. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; Males had lower GAF scores than females, both at intake and at 1 year. Males comprised only 40% (12 out of 39) of the early remission group. For females only, early remission was strongly and positively correlated with bilateral lentiform and striatal volumes. For males, there was no such relationship. &lt;b&gt;&lt;i&gt;Conclusion:&lt;/i&gt;&lt;/b&gt; Larger striato-thalamic volume correlated with early remission in females only. These baseline MRI findings were unlikely to be confounded by antipsychotic treatment and chronicity. These brain morphological markers show gender dimorphism and may assist in the prediction of early remission in newly diagnosed schizophrenia.</jats:p

    Trends in contemporary advanced heart failure management: an in-depth review over 30 years of heart transplant service in Hong Kong

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    Background : The year 2022 marks the 30th anniversary of heart transplant service in Hong Kong (HK). In this study, we describe prevailing trends and outcomes of advanced heart failure (AHF), including heart transplantations (HTx), in HK over the past 30 years. Methods : Trends in heart failure prevalence in HK from 1993 to 2021 were analyzed based on data from the Hospital Authority Clinical Data and Reporting System. All AHF patients referred for HTx consideration between 1992 and 2021 were reviewed. The bridge-to-transplant (BTT) utilization of short-term mechanical circulatory support (ST-MCS) devices, including venoarterial extracorporeal membrane oxygenation (VA-ECMO) and durable left ventricular assist devices (LVADs), from 2010 to 2021 was reviewed. Results : Overall, 237 heart transplants were performed in HK, with 10-year posttransplant and median survival of 68.1% and 18.7 years, respectively. An increase in AHF clinic referrals was correlated with increasing heart failure prevalence (R2=0.635, P<0.001). In total, 146 referrals were made for ST-MCS, and an observed increase in ST-MCS referrals was correlated with increasing VA-ECMO utilization (R2=0.849, P<0.001). Among 62 patients accepted for AHF therapy, those with durable LVAD implementation had better 1-year survival (71.5%) than those receiving an extracorporeal CentriMag (Levitronix) device as BTT (40%, P=0.008). In total, 143 LVADs were implanted, with 130 as BTT or bridge-to-candidacy (BTC) methods. The survival rate among the 130 BTT/BTC LVAD patients resembled that of HTx recipients (73.8% vs. 69.8% at 9 years, P=0.296). Conclusions: The burden of AHF management has increased and gained complexity over the past 30 years in Hong Kong
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