3,406 research outputs found

    White matter integrity in dyskinetic cerebral palsy: Relationship with intelligence quotient and executive function

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    Background: Dyskinetic cerebral palsy (CP) is one of the most disabling motor types of CP and has been classically associated with injury to the basal ganglia and thalamus. Although cognitive dysfunction is common in CP, there is a paucity of published quantitative analyses investigating the relationship between white matter (WM) microstructure and cognition in this CP type. Aims: This study aims (1) to compare brain WM microstructure between people with dyskinetic CP and healthy controls, (2) to identify brain regions where WM microstructure is related to intelligence and (3) to identify brain regions where WM microstructure is related to executive function in people with dyskinetic CP and (4) to identify brain regions where the correlations are different between controls and people with CP in IQ and executive functions. Patients and methods: Thirty-three participants with dyskinetic CP (mean +/- SD age: 24.42 +/- 12.61, 15 female) were age and sex matched with 33 controls. Participants underwent a comprehensive neuropsychological battery to assess intelligence quotient (IQ) and four executive function domains (attentional control, cognitive flexibility, goal setting and information processing). Diffusion weighted MRI scans were acquired at 3T. Voxel-based whole brain groupwise analyses were used to compare fractional anisotropy (FA) and of the CP group to the matched controls using a general lineal model. Further general linear models were used to identify regions where white matter FA correlated with IQ and each of the executive function domains. Results: White matter FA was significantly reduced in the CP group in all cerebral lobes, predominantly in regions connected with the parietal and to a lesser extent the temporal lobes. There was no significant correlation between IQ or any of the four executive function domains and WM microstructure in the control group. In participants with CP, lower IQ was associated with lower FA in all cerebral lobes, predominantly in locations that also showed reduced FA compared to controls. Attentional control, goal setting and information processing did not correlate with WM microstructure in the CP group. Cognitive flexibility was associated with FA in regions known to contain connections with the frontal lobe (such as the superior longitudinal fasciculus and cingulum) as well as regions not known to contain tracts directly connected with the frontal lobe (such as the posterior corona radiata, posterior thalamic radiation, retrolenticular part of internal capsule, tapetum, body and splenium of corpus callosum). Conclusion: The widespread loss in the integrity of WM tissue is mainly located in the parietal lobe and related to IQ in dyskinetic CP. Unexpectedly, executive functions are only related with WM microstructure in regions containing fronto-cortical and posterior cortico-subcortical pathways, and not being specifically related to the state of fronto-striatal pathways which might be due to brain reorganization. Further studies of this nature may improve our understanding of the neurobiological bases of cognitive impairments after early brain insult

    Life on a scale:Deep brain stimulation in anorexia nervosa

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    Anorexia nervosa (AN) is a severe psychiatric disorder marked by low body weight, body image abnormalities, and anxiety and shows elevated rates of morbidity, comorbidity and mortality. Given the limited availability of evidence-based treatments, there is an urgent need to investigate new therapeutic options that are informed by the disorder’s underlying neurobiological mechanisms. This thesis represents the first study in the Netherlands and one of a limited number globally to evaluate the efficacy, safety, and tolerability of deep brain stimulation (DBS) in the treatment of AN. DBS has the advantage of being both reversible and adjustable. Beyond assessing the primary impact of DBS on body weight, psychological parameters, and quality of life, this research is novel in its comprehensive approach. We integrated evaluations of efficacy with critical examinations of the functional impact of DBS in AN, including fMRI, electroencephalography EEG, as well as endocrinological and metabolic assessments. Furthermore, this work situates AN within a broader theoretical framework, specifically focusing on its manifestation as a form of self-destructive behavior. Finally, we reflect on the practical, ethical and philosophical aspects of conducting an experimental, invasive procedure in a vulnerable patient group. This thesis deepens our understanding of the neurobiological underpinnings of AN and paves the way for future research and potential clinical applications of DBS in the management of severe and enduring AN

    Evaluating the anticipated outcomes of MRI seizure image from open-source tool- Prototype approach

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    Epileptic Seizure is an abnormal neuronal exertion in the brain, affecting nearly 70 million of the world's population (Ngugi et al., 2010). So many open-source neuroimaging tools are used for metabolism checkups and analysis purposes. The scope of open-source tools like MATLAB, Slicer 3D, Brain Suite21a, SPM, and MedCalc are explained in this paper. MATLAB was used by 60% of the researchers for their image processing and 10% of them use their proprietary software. More than 30% of the researchers use other open-source software tools with their processing techniques for the study of magnetic resonance seizure image

    Introduction to Psychology

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    Introduction to Psychology is a modified version of Psychology 2e - OpenStax

    “Men are the alphas. Men can't be hurt. Men can't be victims” - Narrative, identity, and male victims of female perpetrated intimate partner abuse.

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    This thesis details the process and analysis of the ‘Hard to Tell’ study, a qualitative, narrative study examining how male victims of female perpetrated intimate partner abuse (IPA) tell their story, and what it might mean for their identity. The study consisted of life-story interviews with 18 self-identifying male victims. Between them they described the full range of abuse, including physical, sexual, emotional, psychological, financial, controlling, coercive, and legal and administrative. The differing nature of these forms of abuse meant that some were easier to describe in narrative form, which carried significant implications for their ability to make sense of their experiences and explain it to others. Analysis was informed by a complex and dynamic understanding of identity, including key concepts from Narrative Identity Theory (McAdams, 2018; Bamberg, 2011) and Positioning Theory (Korobov, 2010; 2015). In telling their story, these male survivors were driven to defend against powerful cultural narratives of masculinity and male perpetration that contrasted with their experience as a man and as a victim. In doing so they drew upon other cultural narratives such as mental ill-health and childhood trauma to attain a valid identity position. Cultural narratives such as those of coercive controlling abuse and narcissism, enabled them to identify their abuse and sidestep gendered assumptions of perpetration. This thesis proposes a model of identity work within autobiographical narration that incorporates key components of the individual, audience, context, and culture. A prominent feature of these men’s stories was the role played by third parties, who enabled them to reframe their experience as an abuse narrative and begin a process of escape and recovery. This places professionals at the heart of this model, as audience and co-producer within a critical process of narrative sense making and identity validation

    Clinical and imaging biomarkers of audiovestibular function in infratentorial superficial siderosis

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    Disabling hearing loss is known to affect over 400 million people worldwide while the lifetime prevalence of dizziness can be as high as 40%. Rare causes for hearing and balance impairment are often understudied. Infratentorial (classical) superficial siderosis (iSS) is a rare but sometimes disabling complex neurological condition most often associated with hearing and balance impairment, and myelopathy. Olfactory loss has been reported but not yet systematically studied. iSS results from a chronic low-grade and low volume bleeding into the cerebrospinal fluid and the deposition of iron-degradation products (predominantly haemosiderin) in the subpial layers of the central nervous system, with predilection for the cerebellum and the vestibulocochlear nerves. Magnetic resonance imaging (MRI) allows haemosiderin to be visualised in-vivo and is the mainstream diagnostic modality. Due to the assumed rarity of iSS (prevalence of 0.03-0.14%), our research opportunities are limited. Few dedicated studies describe iSS-related audiovestibular (AV) findings, often limited to case-series, with mixed findings. There is currently no robust evidence that the radiological haemosiderin appearances correlate with the objective clinical tests. This project focuses on phenotyping the AV function in iSS and identifies predominantly retrocochlear hearing loss with features suggestive of central auditory dysfunction, and mixed vestibular (predominantly cerebellar) dysfunction. This work introduces and validates an imaging rating scale aiming to capture the anatomical extent of haemosiderin deposits visualised on MRI in a standardised and reproducible way. The scale demonstrates excellent reliability and good validity, with the scores correlating with hearing thresholds. This project estimates the prevalence of MRI-defined iSS in a large UK Biobank sample, similar to other rare neurootological disorders. Using patient/self-report measures, this work captures markedly low health-states of individuals with iSS and identifies possible iSS-specific auditory characteristics. Finally, the work identifies high prevalence of olfactory dysfunction in individuals with iSS

    Measuring white matter microstructure in 1,457 cannabis users and 1,441 controls : A systematic review of diffusion-weighted MRI studies

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    Introduction: Cannabis is the most widely used regulated substance by youth and adults. Cannabis use has been associated with psychosocial problems, which have been partly ascribed to neurobiological changes. Emerging evidence to date from diffusion-MRI studies shows that cannabis users compared to controls show poorer integrity of white matter fibre tracts, which structurally connect distinct brain regions to facilitate neural communication. However, the most recent evidence from diffusion-MRI studies thus far has yet to be integrated. Therefore, it is unclear if white matter differences in cannabis users are evident consistently in selected locations, in specific diffusion-MRI metrics, and whether these differences in metrics are associated with cannabis exposure levels. Methods: We systematically reviewed the results from diffusion-MRI imaging studies that compared white matter differences between cannabis users and controls. We also examined the associations between cannabis exposure and other behavioral variables due to changes in white matter. Our review was pre-registered in PROSPERO (ID: 258250; https://www.crd.york.ac.uk/prospero/). Results: We identified 30 diffusion-MRI studies including 1,457 cannabis users and 1,441 controls aged 16-to-45 years. All but 6 studies reported group differences in white matter integrity. The most consistent differences between cannabis users and controls were lower fractional anisotropy within the arcuate/superior longitudinal fasciculus (7 studies), and lower fractional anisotropy of the corpus callosum (6 studies) as well as higher mean diffusivity and trace (4 studies). Differences in fractional anisotropy were associated with cannabis use onset (4 studies), especially in the corpus callosum (3 studies). Discussion: The mechanisms underscoring white matter differences are unclear, and they may include effects of cannabis use onset during youth, neurotoxic effects or neuro adaptations from regular exposure to tetrahydrocannabinol (THC), which exerts its effects by binding to brain receptors, or a neurobiological vulnerability predating the onset of cannabis use. Future multimodal neuroimaging studies, including recently developed advanced diffusion-MRI metrics, can be used to track cannabis users over time and to define with precision when and which region of the brain the white matter changes commence in youth cannabis users, and whether cessation of use recovers white matter differences. Systematic review registration: www.crd.york.ac.uk/prospero/, identifier: 258250
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