Browsing by Subject "Neuroimaging"

Now showing 1 - 3 of 3
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    Open Access
    Nonvisual multisensory impairment of body perception in anorexia nervosa: a systematic review of neuropsychological studies
    (Public Library of Science, 2014) Gaudio, Santino; Brooks, Samantha Jane; Riva, Giuseppe
    BACKGROUND: Body image distortion is a central symptom of Anorexia Nervosa (AN). Even if corporeal awareness is multisensory majority of AN studies mainly investigated visual misperception. We systematically reviewed AN studies that have investigated different nonvisual sensory inputs using an integrative multisensory approach to body perception. We also discussed the findings in the light of AN neuroimaging evidence. METHODS: PubMed and PsycINFO were searched until March, 2014. To be included in the review, studies were mainly required to: investigate a sample of patients with current or past AN and a control group and use tasks that directly elicited one or more nonvisual sensory domains. RESULTS: Thirteen studies were included. They studied a total of 223 people with current or past AN and 273 control subjects. Overall, results show impairment in tactile and proprioceptive domains of body perception in AN patients. Interoception and multisensory integration have been poorly explored directly in AN patients. A limitation of this review is the relatively small amount of literature available. CONCLUSIONS: Our results showed that AN patients had a multisensory impairment of body perception that goes beyond visual misperception and involves tactile and proprioceptive sensory components. Furthermore, impairment of tactile and proprioceptive components may be associated with parietal cortex alterations in AN patients. Interoception and multisensory integration have been weakly explored directly. Further research, using multisensory approaches as well as neuroimaging techniques, is needed to better define the complexity of body image distortion in AN. Key FINDINGS: The review suggests an altered capacity of AN patients in processing and integration of bodily signals: body parts are experienced as dissociated from their holistic and perceptive dimensions. Specifically, it is likely that not only perception but memory, and in particular sensorimotor/proprioceptive memory, probably shapes bodily experience in patients with AN.
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    The neural correlates of intimate partner violence in women
    (2011) Flegar, S; Fouche, J P; Jordaan, E; Marais, S; Spottiswoode, B; Stein, Dan J; Vythilingum, B
    Objective: To examine hippocampal volume and white matter tracts in women with and without intimate partner violence (IPV). Method: Nineteen women with IPV exposure in the last year, and 21 women without IPV exposure in the last year underwent structural magnetic resonance imaging (MRI) including diffusion tensor imaging (DTI) sequences. Additional data on alcohol use and presence of psychiatric disorder was collected. Differences in fractional anisotropy (FA) between the two groups were examined, using a statistical model that included demographic measures, alcohol use and psychiatric disorder. Results: IPV subjects did not demonstrate significantly different hippocampal volumes compared to subjects without recent IPV. FA was, however, significantly reduced in the body of the corpus callosum of IPV subjects. Adjusting for age, alcohol use, smoking and psychiatric diagnosis did not change the significance of the result. Conclusion: Data on hippocampal volume in IPV are inconsistent, perhaps reflecting the fact that multiple factors influence this measure. Reduced FA in the body of the corpus callosum in IPV suggests altered integrity of this white matter tract; additional work is needed to address the underlying mechanisms and clinical correlates of this finding.
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    Toward identifying reproducible brain signatures of obsessive-compulsive profiles: rationale and methods for a new global initiative
    (2020-02-14) Simpson, Helen B; van den Heuvel, Odile A; Miguel, Euripedes C; Reddy, Y. C J; Stein, Dan J; Lewis-Fernández, Roberto; Shavitt, Roseli G; Lochner, Christine; Pouwels, Petra J W; Narayanawamy, Janardhanan C; Venkatasubramanian, Ganesan; Hezel, Dianne M; Vriend, Chris; Batistuzzo, Marcelo C; Hoexter, Marcelo Q; de Joode, Niels T; Costa, Daniel L; de Mathis, Maria A; Sheshachala, Karthik; Narayan, Madhuri; van Balkom, Anton J L M; Batelaan, Neeltje M; Venkataram, Shivakumar; Cherian, Anish; Marincowitz, Clara; Pannekoek, Nienke; Stovezky, Yael R; Mare, Karen; Liu, Feng; Otaduy, Maria C G; Pastorello, Bruno; Rao, Rashmi; Katechis, Martha; Van Meter, Page; Wall, Melanie
    Background Obsessive-compulsive disorder (OCD) has a lifetime prevalence of 2–3% and is a leading cause of global disability. Brain circuit abnormalities in individuals with OCD have been identified, but important knowledge gaps remain. The goal of the new global initiative described in this paper is to identify robust and reproducible brain signatures of measurable behaviors and clinical symptoms that are common in individuals with OCD. A global approach was chosen to accelerate discovery, to increase rigor and transparency, and to ensure generalizability of results. Methods We will study 250 medication-free adults with OCD, 100 unaffected adult siblings of individuals with OCD, and 250 healthy control subjects at five expert research sites across five countries (Brazil, India, Netherlands, South Africa, and the U.S.). All participants will receive clinical evaluation, neurocognitive assessment, and magnetic resonance imaging (MRI). The imaging will examine multiple brain circuits hypothesized to underlie OCD behaviors, focusing on morphometry (T1-weighted MRI), structural connectivity (Diffusion Tensor Imaging), and functional connectivity (resting-state fMRI). In addition to analyzing each imaging modality separately, we will also use multi-modal fusion with machine learning statistical methods in an attempt to derive imaging signatures that distinguish individuals with OCD from unaffected siblings and healthy controls (Aim #1). Then we will examine how these imaging signatures link to behavioral performance on neurocognitive tasks that probe these same circuits as well as to clinical profiles (Aim #2). Finally, we will explore how specific environmental features (childhood trauma, socioeconomic status, and religiosity) moderate these brain-behavior associations. Discussion Using harmonized methods for data collection and analysis, we will conduct the largest neurocognitive and multimodal-imaging study in medication-free subjects with OCD to date. By recruiting a large, ethno-culturally diverse sample, we will test whether there are robust biosignatures of core OCD features that transcend countries and cultures. If so, future studies can use these brain signatures to reveal trans-diagnostic disease dimensions, chart when these signatures arise during development, and identify treatments that target these circuit abnormalities directly. The long-term goal of this research is to change not only how we conceptualize OCD but also how we diagnose and treat it.