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Michael C Stevens - One of the best experts on this subject based on the ideXlab platform.
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differences in Resting State functional magnetic resonance imaging functional Network connectivity between schizophrenia and psychotic bipolar probands and their unaffected first degree relatives
Biological Psychiatry, 2012Co-Authors: Vince D. Calhoun, Michael C Stevens, Shashwath A Meda, Adrienne Gill, Raymond P Lorenzoni, David C Glahn, John A SweeneyAbstract:Background Schizophrenia and bipolar disorder share overlapping symptoms and genetic etiology. Functional brain dysconnectivity is seen in both disorders. Methods We compared 70 schizophrenia and 64 psychotic bipolar probands, their respective unaffected first-degree relatives ( n = 70, and n = 52), and 118 healthy subjects, all group age-, gender-, and ethnicity-matched. We used functional Network connectivity analysis to measure differential connectivity among 16 functional magnetic resonance imaging Resting State Networks. First, we examined connectivity differences between probands and control subjects. Next, we probed these dysfunctional connections in relatives for potential endophenotypes. Network connectivity was then correlated with Positive and Negative Syndrome Scale (PANSS) scores to reveal clinical relationships. Results Three different Network pairs were differentially connected in probands (false-discovery rate corrected q Conclusions Schizophrenia and psychotic bipolar probands share several abnormal Resting State Network connections, but there are also unique neural Network underpinnings between disorders. We identified specific connections that might also be candidate psychosis endophenotypes.
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multiple Resting State Network functional connectivity abnormalities in mild traumatic brain injury
Brain Imaging and Behavior, 2012Co-Authors: Michael C Stevens, David W Lovejoy, Jinsuh Kim, Howard Oakes, Inam Kureshi, Suzanne T WittAbstract:Several reports show that traumatic brain injury (TBI) results in abnormalities in the coordinated activation among brain regions. Because most previous studies examined moderate/severe TBI, the extensiveness of functional connectivity abnormalities and their relationship to postconcussive complaints or white matter microstructural damage are unclear in mild TBI. This study characterized widespread injury effects on multiple integrated neural Networks typically observed during a task-unconstrained “Resting State” in mild TBI patients. Whole brain functional connectivity for twelve separate Networks was identified using independent component analysis (ICA) of fMRI data collected from thirty mild TBI patients mostly free of macroscopic intracerebral injury and thirty demographically-matched healthy control participants. Voxelwise group comparisons found abnormal mild TBI functional connectivity in every brain Network identified by ICA, including visual processing, motor, limbic, and numerous circuits believed to underlie executive cognition. Abnormalities not only included functional connectivity deficits, but also enhancements possibly reflecting compensatory neural processes. Postconcussive symptom severity was linked to abnormal regional connectivity within nearly every brain Network identified, particularly anterior cingulate. A recently developed multivariate technique that identifies links between whole brain profiles of functional and anatomical connectivity identified several novel mild TBI abnormalities, and represents a potentially important new tool in the study of the complex neurobiological sequelae of TBI.
Hubert Preissl - One of the best experts on this subject based on the ideXlab platform.
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the obese brain association of body mass index and insulin sensitivity with Resting State Network functional connectivity
Human Brain Mapping, 2012Co-Authors: Stephanie Kullmann, Martin Heni, Ralf Veit, Caroline Ketterer, Fritz Schick, Hansulrich Haring, Andreas Fritsche, Hubert PreisslAbstract:Obesity is a key risk factor for the development of insulin resistance, Type 2 diabetes and associated diseases; thus, it has become a major public health concern. In this context, a detailed understanding of brain Networks regulating food intake, including hormonal modulation, is crucial. At present, little is known about potential alterations of cerebral Networks regulating ingestive behavior. We used "Resting State" functional magnetic resonance imaging to investigate the functional connectivity integrity of Resting State Networks (RSNs) related to food intake in lean and obese subjects using independent component analysis. Our results showed altered functional connectivity strength in obese compared to lean subjects in the default mode Network (DMN) and temporal lobe Network. In the DMN, obese subjects showed in the precuneus bilaterally increased and in the right anterior cingulate decreased functional connectivity strength. Furthermore, in the temporal lobe Network, obese subjects showed decreased functional connectivity strength in the left insular cortex. The functional connectivity magnitude significantly correlated with body mass index (BMI). Two further RSNs, including brain regions associated with food and reward processing, did not show BMI, but insulin associated functional connectivity strength. Here, the left orbitofrontal cortex and right putamen functional connectivity strength was positively correlated with fasting insulin levels and negatively correlated with insulin sensitivity index. Taken together, these results complement and expand previous functional neuroimaging findings by demonstrating that obesity and insulin levels influence brain function during rest in Networks supporting reward and food regulation.
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the obese brain association of body mass index and insulin sensitivity with Resting State Network functional connectivity
Human Brain Mapping, 2012Co-Authors: Stephanie Kullmann, Martin Heni, Ralf Veit, Caroline Ketterer, Fritz Schick, Hansulrich Haring, Andreas Fritsche, Hubert PreisslAbstract:Obesity is a key risk factor for the development of insulin resistance, Type 2 diabetes and associated diseases; thus, it has become a major public health concern. In this context, a detailed understanding of brain Networks regulating food intake, including hormonal modulation, is crucial. At present, little is known about potential alterations of cerebral Networks regulating ingestive behavior. We used “Resting State” functional magnetic resonance imaging to investigate the functional connectivity integrity of Resting State Networks (RSNs) related to food intake in lean and obese subjects using independent component analysis. Our results showed altered functional connectivity strength in obese compared to lean subjects in the default mode Network (DMN) and temporal lobe Network. In the DMN, obese subjects showed in the precuneus bilaterally increased and in the right anterior cingulate decreased functional connectivity strength. Furthermore, in the temporal lobe Network, obese subjects showed decreased functional connectivity strength in the left insular cortex. The functional connectivity magnitude significantly correlated with body mass index (BMI). Two further RSNs, including brain regions associated with food and reward processing, did not show BMI, but insulin associated functional connectivity strength. Here, the left orbitofrontal cortex and right putamen functional connectivity strength was positively correlated with fasting insulin levels and negatively correlated with insulin sensitivity index. Taken together, these results complement and expand previous functional neuroimaging findings by demonstrating that obesity and insulin levels influence brain function during rest in Networks supporting reward and food regulation. Hum Brain Mapp, 2011. © 2011 Wiley-Liss, Inc.
David L Brody - One of the best experts on this subject based on the ideXlab platform.
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individualized connectome targeted transcranial magnetic stimulation for neuropsychiatric sequelae of repetitive traumatic brain injury in a retired nfl player
Journal of Neuropsychiatry and Clinical Neurosciences, 2019Co-Authors: Shan H Siddiqi, Carl D Hacker, Timothy O Laumann, Nicholas T Trapp, Pashtun Shahim, Sridhar Kandala, Alexandre R Carter, David L BrodyAbstract:Objective:The recent advent of individualized Resting-State Network mapping (RSNM) has revealed substantial interindividual variability in anatomical localization of brain Networks identified by us...
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rtms with individualized Resting State Network mapping for neuropsychiatric sequelae of repetitive traumatic brain injury in a retired nfl player
bioRxiv, 2017Co-Authors: Shan H Siddiqi, Carl D Hacker, Timothy O Laumann, Nicholas T Trapp, Pashtun Shahim, Sridhar Kandala, Alexandre R Carter, David L BrodyAbstract:Objective: To investigate clinical utility and brain Network changes following Resting-State functional MRI (rsfMRI)-targeted bilateral repetitive transcranial magnetic stimulation (rTMS) in a subject with neuropsychiatric disturbances associated with chronic/repetitive traumatic brain injury (TBI). Methods: Individual-level connectome mapping was used to identify left/right dorsolateral prefrontal targets with maximum anticorrelation between dorsal attention Network (DAN) and default mode Network (DMN). Twenty sessions of left-sided excitatory and right-sided inhibitory rTMS were delivered to a retired NFL defensive lineman as part of a randomized, controlled trial. Montgomery-Asberg Depression Rating Scale (MADRS), cognitive testing, headache measures, and rsfMRI were conducted before and after treatment. Pre-treatment rsfMRI findings were compared to 12 age/gender-matched healthy individuals and 10 subjects with depression and TBI. Results: MADRS score improved from 32 at baseline to 9 immediately after treatment and remained at 9 upon six-week follow-up. Cognitive/headache measures showed mild improvements and treatments were well-tolerated. In comparison with both comparator groups, baseline rsfMRI revealed near-absence of the typical DAN-DMN anticorrelation and differences in limbic functional connectivity with nucleus accumbens (NAcc). These differences in limbic-NAcc connectivity were attenuated with treatment. The identified left- and right-sided rTMS targets were, respectively, 36/30 mm away from traditional clinical targets for major depression and 10-18/7-8 mm away from targets identified by previously-described imaging-based targeting methods. Conclusions: rsfMRI-targeted rTMS may be a promising treatment for neuropsychiatric sequelae of repetitive TBI. Future research will aim to verify this observation, directly compare targeting methods, and better characterize the distinctions between single and repetitive TBI.
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individualized connectome targeted transcranial magnetic stimulation for neuropsychiatric sequelae of repetitive traumatic brain injury in a retired nfl player
bioRxiv, 2017Co-Authors: Shan H Siddiqi, Carl D Hacker, Timothy O Laumann, Nicholas T Trapp, Pashtun Shahim, Sridhar Kandala, Alexandre R Carter, David L BrodyAbstract:The recent advent of individualized Resting-State Network mapping (RSNM) has revealed substantial inter-individual variability in anatomical localization of brain Networks identified using Resting-State functional MRI (rsfMRI). Such variability may be particularly important after repetitive traumatic brain injury (TBI), which is associated with treatment-resistant depression. RSNM enables personalized targeting of repetitive transcranial magnetic stimulation (rTMS), a focal brain stimulation technique that relieves depression when administered over dorsolateral prefrontal cortex. RSNM was used to identify left/right dorsolateral prefrontal rTMS targets with maximal difference between dorsal attention Network and default mode Network (DMN) correlations. These targets were spatially distinct from those identified by prior methods. The method was evaluated by administering twenty sessions of left-sided excitatory and right-sided inhibitory rTMS to a retired NFL defensive lineman with progressive treatment-resistant neuropsychiatric disturbances. Treatment led to improvement in Montgomery-Asberg Depression Rating Scale (72%), cognitive testing, and headache scales. In comparison with healthy individuals and subjects with TBI-associated depression, baseline rsfMRI revealed substantially elevated DMN connectivity with medial temporal lobe (MTL). Serial rsfMRI scans showed gradual improvement in MTL-DMN connectivity and stimulation site connectivity with subgenual anterior cingulate cortex. This highlights the possibility of individualized neuromodulation and biomarker-based monitoring for neuropsychiatric sequelae of repetitive TBI.
Thomas Meindl - One of the best experts on this subject based on the ideXlab platform.
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prefrontal transcranial direct current stimulation for treatment of schizophrenia with predominant negative symptoms a double blind sham controlled proof of concept study
Schizophrenia Bulletin, 2016Co-Authors: Ulrich Palm, D Keeser, Alkomiet Hasan, M Kupka, Janusch Blautzik, Nina Sarubin, Filipa Kaymakanova, Ina Unger, Peter Falkai, Thomas MeindlAbstract:Negative symptoms are highly relevant in the long-term course of schizophrenia and are an important target domain for the development of novel interventions. Recently, transcranial direct current stimulation (tDCS) of the prefrontal cortex has been investigated as a treatment option in schizophrenia. In this proof-of-concept study, 20 schizophrenia patients with predominantly negative symptoms were randomized to either 10 sessions of add-on active (2 mA, 20min) or sham tDCS (anode: left DLPFC/F3; cathode: right supraorbital/F4). Primary outcome measure was the change in the Scale for the Assessment of Negative Symptoms (SANS) sum score; secondary outcomes included reduction in Positive and Negative Syndrome Scale (PANSS) scores and improvement of depressive symptoms, cognitive processing speed, and executive functioning. Sixteen patients underwent 4 functional connectivity magnetic resonance imaging (fcMRI) scans (pre and post 1st and pre and post 10th tDCS) to investigate changes in Resting State Network connectivity after tDCS. Per-protocol analysis showed a significantly greater decrease in SANS score after active (-36.1%) than after sham tDCS (-0.7%). PANSS sum scores decreased significantly more with active (-23.4%) than with sham stimulation (-2.2%). Explorative analysis of fcMRI data indicated changes in subgenual cortex and dorsolateral prefrontal cortex (DLPFC) connectivity within frontal-thalamic-temporo-parietal Networks. The results of this first proof-of-concept study indicate that prefrontal tDCS may be a promising intervention for treatment of schizophrenia with predominant negative symptoms. Large-scale randomized controlled studies are needed to further establish prefrontal tDCS as novel treatment for negative symptoms in schizophrenia.
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prefrontal transcranial direct current stimulation changes connectivity of Resting State Networks during fmri
The Journal of Neuroscience, 2011Co-Authors: D Keeser, Thomas Meindl, Julie Bor, Ulrich Palm, Oliver Pogarell, Christoph Mulert, Jerome Brunelin, Hansjurgen Moller, Maximilian F Reiser, Frank PadbergAbstract:Transcranial direct current stimulation (tDCS) has been proposed for experimental and therapeutic modulation of regional brain function. Specifically, anodal tDCS of the dorsolateral prefrontal cortex (DLPFC) together with cathodal tDCS of the supraorbital region have been associated with improvement of cognition and mood, and have been suggested for the treatment of several neurological and psychiatric disorders. Although modeled mathematically, the distribution, direction, and extent of tDCS-mediated effects on brain physiology are not well understood. The current study investigates whether tDCS of the human prefrontal cortex modulates Resting-State Network (RSN) connectivity measured by functional magnetic resonance imaging (fMRI). Thirteen healthy subjects underwent real and sham tDCS in random order on separate days. tDCS was applied for 20 min at 2 mA with the anode positioned over the left DLPFC and the cathode over the right supraorbital region. Patterns of Resting-State brain connectivity were assessed before and after tDCS with 3 T fMRI, and changes were analyzed for relevant Networks related to the stimulation–electrode localizations. At baseline, four RSNs were detected, corresponding to the default mode Network (DMN), the left and right frontal-parietal Networks (FPNs) and the self-referential Network. After real tDCS and compared with sham tDCS, significant changes of regional brain connectivity were found for the DMN and the FPNs both close to the primary stimulation site and in connected brain regions. These findings show that prefrontal tDCS modulates Resting-State functional connectivity in distinct functional Networks of the human brain.
Suzanne T Witt - One of the best experts on this subject based on the ideXlab platform.
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altered brain microState dynamics in adolescents with narcolepsy
Frontiers in Human Neuroscience, 2016Co-Authors: Natasha Morales Drissi, Attila Szakacs, Suzanne T Witt, Anna Wretman, Martin Ulander, Henrietta Stahlbrandt, Niklas Darin, Tove Hallbook, Annemarie LandtblomAbstract:Narcolepsy is a chronic sleep disorder caused by a loss of hypocretin-1 producing neurons in the hypothalamus. Previous neuroimaging studies have investigated brain function in narcolepsy during rest using positron emission tomography (PET) and single photon emission computed tomography (SPECT). In addition to hypothalamic and thalamic dysfunction they showed aberrant prefrontal perfusion and glucose metabolism in narcolepsy. Given these findings in brain structure and metabolism in narcolepsy, we anticipated that changes in functional magnetic resonance imaging (fMRI) Resting State Network dynamics might also be apparent in patients with narcolepsy. The objective of this study was to investigate and describe brain microState activity in adolescents with narcolepsy and correlate these to Resting State Networks using simultaneous fMRI and EEG. Sixteen adolescents (ages 13-20) with a confirmed diagnosis of narcolepsy were recruited and compared to age-matched healthy controls. Simultaneous EEG and fMRI data were collected during 10 minutes of wakeful rest. EEG data were analyzed for microStates, which are discrete epochs of stable global brain States obtained from topographical EEG analysis. Functional MRI data were analyzed for Resting State Networks. Data showed that narcolepsy patients were less likely than controls to spend time in a microState which we found to be related to the default mode Network and may suggest a disruption of this Network that is disease specific. We concluded that adolescents with narcolepsy have altered Resting State brain dynamics.
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multiple Resting State Network functional connectivity abnormalities in mild traumatic brain injury
Brain Imaging and Behavior, 2012Co-Authors: Michael C Stevens, David W Lovejoy, Jinsuh Kim, Howard Oakes, Inam Kureshi, Suzanne T WittAbstract:Several reports show that traumatic brain injury (TBI) results in abnormalities in the coordinated activation among brain regions. Because most previous studies examined moderate/severe TBI, the extensiveness of functional connectivity abnormalities and their relationship to postconcussive complaints or white matter microstructural damage are unclear in mild TBI. This study characterized widespread injury effects on multiple integrated neural Networks typically observed during a task-unconstrained “Resting State” in mild TBI patients. Whole brain functional connectivity for twelve separate Networks was identified using independent component analysis (ICA) of fMRI data collected from thirty mild TBI patients mostly free of macroscopic intracerebral injury and thirty demographically-matched healthy control participants. Voxelwise group comparisons found abnormal mild TBI functional connectivity in every brain Network identified by ICA, including visual processing, motor, limbic, and numerous circuits believed to underlie executive cognition. Abnormalities not only included functional connectivity deficits, but also enhancements possibly reflecting compensatory neural processes. Postconcussive symptom severity was linked to abnormal regional connectivity within nearly every brain Network identified, particularly anterior cingulate. A recently developed multivariate technique that identifies links between whole brain profiles of functional and anatomical connectivity identified several novel mild TBI abnormalities, and represents a potentially important new tool in the study of the complex neurobiological sequelae of TBI.