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We qualitatively explored the impact of preoperative mindfulness-based stress reduction (MBSR) on total knee arthroplasty (TKA) experiences. Participants (n = 10) who received MBSR prior to TKA participated in semi-structured interviews concerning their experiences with MBSR and its perceived impact on surgery. We analyzed interviews according to reflexive thematic analysis, and coded data into three main themes: 1) Impact of MBSR on surgery experiences; 2) Contributors to change; and 3) Motivations for participation. Participants noted they were able to relax, feel more confident, and cope more effectively during the preoperative period, and that others in their lives noticed positive changes following their participation in MBSR. Participants' openness to mindfulness and health-related beliefs and may have contributed to the positive impacts they experienced from MBSR. Participants described being motivated to participate in MBSR to help them prepare for their surgery and to learn new coping strategies. Participants described a strong level of commitment to the intervention. With further research, integration of MBSR into prehabilitation for TKA may be appropriate.
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Artroplastia do Joelho , Atenção Plena , Pesquisa Qualitativa , Estresse Psicológico , Humanos , Artroplastia do Joelho/psicologia , Artroplastia do Joelho/métodos , Atenção Plena/métodos , Atenção Plena/normas , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Estresse Psicológico/psicologia , Estresse Psicológico/prevenção & controle , Adaptação Psicológica , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/psicologia , Cuidados Pré-Operatórios/normas , Idoso de 80 Anos ou maisRESUMO
Despite recent advances, there is still a major need to better understand the interactions between brain function and chronic gut inflammation and its clinical implications. Alterations in executive function have previously been identified in several chronic inflammatory conditions, including inflammatory bowel diseases. Inflammation-associated brain alterations can be captured by connectome analysis. Here, we used the resting-state fMRI data from 222 participants comprising three groups (ulcerative colitis (UC), irritable bowel syndrome (IBS), and healthy controls (HC), N = 74 each) to investigate the alterations in functional brain wiring and cortical stability in UC compared to the two control groups and identify possible correlations of these alterations with clinical parameters. Globally, UC participants showed increased functional connectivity and decreased modularity compared to IBS and HC groups. Regionally, UC showed decreased eigenvector centrality in the executive control network (UC < IBS < HC) and increased eigenvector centrality in the visual network (UC > IBS > HC). UC also showed increased connectivity in dorsal attention, somatomotor network, and visual networks, and these enhanced subnetwork connectivities were able to distinguish UC participants from HCs and IBS with high accuracy. Dynamic functional connectome analysis revealed that UC showed enhanced cortical stability in the medial prefrontal cortex (mPFC), which correlated with severe depression and anxiety-related measures. None of the observed brain changes were correlated with disease duration. Together, these findings are consistent with compromised functioning of networks involved in executive function and sensory integration in UC.
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Colite Ulcerativa , Conectoma , Síndrome do Intestino Irritável , Encéfalo , Colite Ulcerativa/complicações , Humanos , Inflamação/complicações , Síndrome do Intestino Irritável/complicaçõesRESUMO
Autonomous sensory meridian response (ASMR) is a perceptual and emotional phenomenon in which specific sensory stimuli elicit a feeling of calm as well as tingling sensations on the scalp, neck, and shoulders. In the current study, we use fMRI to examine whether the motoric and sensory regions of the spinal cord segments associated with these body parts show increased activity during ASMR experiences. Nine individuals with ASMR completed six spinal functional magnetic resonance imaging runs while passively viewing videos. Three of the videos were shown (through pre-testing) to elicit ASMR tingles and three videos did not (i.e., control videos). The results demonstrated that ASMR-related stimuli elicited activity in dorsal (sensory) regions of spinal cord segments C1, C5, and C6; activity was observed in ventral (motoric) regions of segments C2-C8. Similar activity was not detected in response to control videos.
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Meridianos , Emoções/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Medula Espinal/diagnóstico por imagem , Medula Espinal/fisiologiaRESUMO
BACKGROUND: Longitudinal studies assessing depression and anxiety effects on cognition in multiple sclerosis (MS) are limited. OBJECTIVE: We tested whether within-person fluctuations in symptoms of depression or anxiety over time affect cognition in persons with MS, inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and a lifetime history of depression/anxiety disorders (DEP/ANX) but without an immune-mediated inflammatory diseases (IMID). METHODS: We followed participants (MS: 255, IBD: 247, RA: 154, and DEP/ANX: 306) for 3 years. Annually, they completed the hospital anxiety and depression scale (HADS) and cognitive tests including the symbol digit modalities test (SDMT). We evaluated associations of elevated symptoms (scores ⩾ 11) of anxiety (HADS-A) and depression (HADS-D) with SDMT z-scores using multivariable linear models-estimating between-person and within-person effects. RESULTS: Participants with MS performed worse on the SDMT than participants in the DEP/ANX cohort (ß = -0.68; 95% CI: -0.88, -0.48). Participants with elevated HADS-A scores performed worse on the SDMT than those without elevated scores (ß = -0.43; 95% CI: -0.65, -0.21), particularly those with RA. Time-varying within-person elevations in depressive symptoms were associated with worse SDMT performance (ß = -0.12; 95% CI: -0.21, -0.021). CONCLUSIONS: Across persons, elevated symptoms of anxiety adversely affected information processing. Elevated symptoms of depression within-persons over time were associated with declines in information processing speed.
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Depressão , Esclerose Múltipla , Ansiedade , Transtornos de Ansiedade , Humanos , Esclerose Múltipla/complicações , Testes NeuropsicológicosRESUMO
Autonomous sensory meridian response (ASMR) is a sensory-emotional phenomenon in which specific sensory stimuli ("ASMR triggers") reliably elicit feelings of relaxation and tingling sensations on the head, neck, and shoulders. However, there are individual differences in which stimuli elicit ASMR and in the intensity of these responses. In the current research, we used resting-state fMRI to examine the functional connectivity associated with these differences. Fifteen individuals with self-reported ASMR completed the ASMR Checklist, which measures sensitivity to different ASMR triggers, and a resting-state fMRI scan. Checklist scores were entered as covariates to determine whether the functional connectivity of eight resting-state networks differed as a function of participants' sensitivity to five categories of triggers. The results indicated unique patterns of functional connectivity associated with sensitivity to each ASMR trigger category. Sensitivity to two trigger categories was positively correlated with the dorsal attention network, suggesting that ASMR may involve atypical attentional processing.
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Meridianos , Emoções , Humanos , Imageamento por Ressonância MagnéticaRESUMO
Emotional stimuli receive prioritized attentional and motoric processing in the brain. Recent data have indicated that emotional stimuli enhance activity in the cervical spinal cord as well. In the present study, we used fMRI to investigate the specificity of this emotion-dependent spinal cord activity. We examined whether the limb depicted in a passively viewed image (upper vs. lower) differentially influenced activity in the cervical segments that innervate the upper limbs, and whether this effect was enhanced by emotion. Participants completed four fMRI runs: neutral-upper limb, neutral-lower limb, negative-upper limb, and negative-lower limb. The results indicated main effects of limb and emotion, with upper limbs and negative stimuli eliciting greater activity than lower limbs and neutral stimuli, respectively. For upper-limb runs, negative stimuli evoked more activity than did neutral stimuli. Additionally, negative stimuli depicting upper limbs produced stronger responses than did negative stimuli depicting lower limbs. These results suggest that emotional stimuli augment limb-specific responses in the spinal cord.
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Emoções/fisiologia , Extremidades/fisiologia , Neurônios/fisiologia , Medula Espinal/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Adulto JovemRESUMO
PURPOSE: To demonstrate that it is possible to acquire accurate functional magnetic resonance images from thoracic spinal cord neurons. MATERIALS AND METHODS: The lower thoracic spinal dermatomes (T7-T11) on the right side of the body were mechanically stimulated by vibration for 15 participants. Neuronal responses to vibration sensation were measured in the thoracic spinal cord using a HASTE sequence on a 3 Tesla MRI system. RESULTS: Signal increases were observed in the corresponding lower thoracic spinal cord segments ipsilateral to the side of stimulation in the dorsal aspect of the spinal cord. CONCLUSION: This is the first study to provide proof of principle that functional imaging of the entire thoracic spinal cord is possible, by detecting neuronal activity in the thoracic spinal cord during sensory stimulation using spinal fMRI.
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Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Células Receptoras Sensoriais/fisiologia , Medula Espinal/fisiologia , Vibração , Adolescente , Adulto , Vias Aferentes/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Fibras Nervosas Mielinizadas/fisiologia , Neurônios/fisiologia , Corpúsculos de Pacini/fisiologia , Valores de Referência , Vértebras Torácicas , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: The autonomous sensory meridian response (ASMR) is a multimodal perceptual phenomenon in which specific sensory triggers evoke tingling sensations on the scalp, neck, and shoulders; these sensations are accompanied by a positive and calming affective state. Previous functional neuroimaging research has shown that ASMR experiences involve medial prefrontal and sensorimotor brain areas. The purpose of the current study was to examine whether there are structural differences in the cortex of individuals who experience ASMR. METHODS: Seventeen individuals with ASMR and 17 matched control participants completed an MPRAGE structural MRI scan. These data were analyzed to determine if group differences were present for measures of cortical thickness, cortical complexity, sulcal depth, and gyrification. RESULTS: ASMR was associated with reduced cortical thickness in a number of regions including the left precuneus, precentral gyrus, and insula, and the right orbitofrontal cortex, superior frontal cortex, and paracentral lobule. Reduced thickness was observed bilaterally in the supramarginal gyrus. Individuals with ASMR also showed less cortical complexity in the pars opercularis and pars triangularis. CONCLUSIONS: The differences in cortical thickness and complexity were in brain areas whose functions relate to the ASMR experience. These differences include neural regions related to phonological processing, sensorimotor functions, and attention.
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Meridianos , Córtex Motor , Humanos , Encéfalo , Emoções , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Córtex Cerebral/diagnóstico por imagemRESUMO
Background: The open-access UManitoba-JHU functionally defined human white matter (WM) atlas contains specific WM pathways and general WM regions underlying 12 functional brain networks in ICBM152 template space. However, it is not known whether any of these WM networks are disproportionately co-localized with periventricular and/or juxtacortical WM (PVWM and JCWM), which could potentially impact their ability to infer network-specific effects in future studies-particularly in patient populations expected to have disproportionate PVWM and/or JCWM damage. Methods: The current study therefore identified intersecting regions of PVWM and JCWM (defined as WM within 5 mm of the ventricular and cortical boundaries) and: (1) the ICBM152 global WM mask, and (2) all 12 UManitoba-JHU WM networks. Dice Similarity Coefficient (DSC), Jaccard Similarity Coefficient (JSC), and proportion of volume (POV) values between PVWM (and JCWM) and each functionally defined WM network were then compared to corresponding values between PVWM (and JCWM) and global WM. Results: Between the 12 WM networks and PVWM, 8 had lower DSC, JSC, and POV; 1 had lower DSC and JSC, but higher POV; and 3 had higher DSC, JSC, and POV compared to global WM. For JCWM, all 12 WM networks had lower DSC, JSC, and POV compared to global WM. Conclusion: The majority of UManitoba-JHU functionally defined WM networks exhibited lower than average spatial similarity with PVWM, and all exhibited lower than average spatial similarity with JCWM. This suggests that they can be used to explore network-specific WM changes, even in patient populations with known predispositions toward PVWM and/or JCWM damage.
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Reports of cognitive impairment in inflammatory bowel disease (IBD) have been mixed. IBD and cardiovascular disease are often co-morbid, yet it remains unknown whether vascular comorbidity confers a risk for decreased cognitive functioning, as observed in other populations. Participants with IBD were recruited from a longitudinal study of immune-mediated disease. Participants were administered a standardized neuropsychological test protocol, evaluating information processing speed, verbal learning and memory, visual learning and memory, and verbal fluency/executive function. Cognitive test scores were standardized using local regression-based norms, adjusting for age, sex, and education. Vascular risk was calculated using a modified Framingham Risk Score (FRS). We tested the association between FRS and cognitive test scores using a quantile regression model, adjusting for IBD type. Of 84 IBD participants, 54 had ulcerative colitis and 30 had Crohn's disease; mean (SD) age was 53.36 (13.95) years, and a high proportion were females (n = 58). As the risk score (FRS) increased, participants demonstrated lower performance in information processing speed (ß = - 0.12; 95% CI - 0.24, - 0.006) and verbal learning (ß = - 0.14; 95% CI - 0.28, - 0.01) at the 50th percentile. After adjusting for IBD type and disease activity, higher FRS remained associated with lower information processing speed (ß = - 0.14; 95% CI - 0.27, - 0.065). Vascular comorbidity is associated with lower cognitive functioning in persons with IBD, particularly in the area of information processing speed. These findings suggest that prevention, identification, and treatment of vascular comorbidity in IBD may play a critical role for improving functional outcomes in IBD.
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Colite Ulcerativa , Doenças Inflamatórias Intestinais , Feminino , Humanos , Pessoa de Meia-Idade , Masculino , Estudos Longitudinais , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Cognição , Comorbidade , Colite Ulcerativa/epidemiologiaRESUMO
BACKGROUND: Vascular disease and cognitive impairment have been increasingly documented in inflammatory bowel disease (IBD), and both have been individually correlated with changes in brain structure. This study aimed to determine if both macro- and microstructural brain changes are prevalent in IBD and whether alterations in brain structure mediate the relationship between vascular disease and cognitive functioning. METHODS: Eighty-four IBD participants underwent multimodal magnetic resonance imaging. Volumetric and mean diffusivity measures of the thalamus, hippocampus, normal-appearing white matter, and white matter lesions were converted to age- and sex-adjusted z scores. Vascular comorbidity was assessed using a modified Framingham Risk Score and cognition was assessed using a battery of neuropsychological tests. Test scores were standardized using local regression-based norms. We generated summary statistics for the magnetic resonance imaging metrics and cognitive tests, and these were examined using canonical correlation analysis and linear regression modeling. RESULTS: Greater vascular comorbidity was negatively correlated with thalamic, normal-appearing white matter, and white matter lesion volumes. Higher Framingham Risk Score were also correlated with lower processing speed, learning and memory, and verbal fluency. Increased vascular comorbidity was predictive of poorer cognitive functioning, and this effect was almost entirely mediated (94.76%) by differences in brain structure. CONCLUSIONS: Vascular comorbidity is associated with deleterious effects on brain structure and lower cognitive functioning in IBD. These findings suggest that proper identification and treatment of vascular disease is essential to the overall management of IBD, and that certain brain areas may serve as critical targets for predicting the response to therapeutic interventions.
Vascular disease is associated with decreased cognitive performance in persons with inflammatory bowel disease, and this is mainly driven by changes in the brain, including both gray matter and white matter regions.
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Background: Fifty-one percent of individuals with multiple sclerosis (MS) develop cognitive impairment (CI) in information processing speed (IPS). Although IPS scores are associated with health and well-being, neural changes that underlie IPS impairments in MS are not understood. Resting state fMRI can provide insight into brain function changes underlying impairment in persons with MS. Objectives: We aimed to assess functional connectivity (FC) differences in (i) persons with MS compared to healthy controls (HC), (ii) persons with both MS and CI (MS-CI) compared to HC, (iii) persons with MS that are cognitively preserved (MS-CP) compared to HC, (iv) MS-CI compared to MS-CP, and (v) in relation to cognition within the MS group. Methods: We included 107 participants with MS (age 49.5 ± 12.9, 82% women), and 94 controls (age 37.9 ± 15.4, 66% women). Each participant was administered the Symbol Digit Modalities Test (SDMT) and underwent a resting state fMRI scan. The MS-CI group was created by applying a z-score cut-off of ≤-1.5 to locally normalized SDMT scores. The MS-CP group was created by applying a z-score of ≥0. Control groups (HCMS-CI and HCMS-CP) were based on the nearest age-matched HC participants. A whole-brain ROI-to-ROI analysis was performed followed by specific contrasts and a regression analysis. Results: Individuals with MS showed FC differences compared to HC that involved the cerebellum, visual and language-associated brain regions, and the thalamus, hippocampus, and basal ganglia. The MS-CI showed FC differences compared to HCMS-CI that involved the cerebellum, visual and language-associated areas, thalamus, and caudate. SDMT scores were correlated with FC between the cerebellum and lateral occipital cortex in MS. No differences were observed between the MS-CP and HCMS-CP or MS-CI and MS-CP groups. Conclusion: Our findings emphasize FC changes of cerebellar, visual, and language-associated areas in persons with MS. These differences were apparent for (i) all MS participants compared to HC, (ii) MS-CI subgroup and their matched controls, and (iii) the association between FC and SDMT scores within the MS group. Our findings strongly suggest that future work that examines the associations between FC and IPS impairments in MS should focus on the involvement of these regions.
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Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is characterized by inflammation of the gastrointestinal tract and is a disorder of the brain-gut axis. Neuroimaging studies of brain function and structure have helped better understand the relationships between the brain, gut, and comorbidity in IBD. Studies of brain structure have primarily employed voxel-based morphometry to measure grey matter volume and surface-based morphometry to measure cortical thickness. Far fewer studies have employed other surface-based morphometry metrics such as gyrification, cortical complexity, and sulcal depth. In this study, brain structure differences between 72 adults with IBD and 90 healthy controls were assessed using all five metrics. Significant differences were found for cortical thickness with the IBD group showing extensive left-lateralized thinning, and for cortical complexity with the IBD group showing greater complexity in the left fusiform and right posterior cingulate. No significant differences were found in grey matter volume, gyrification, or sulcal depth. Within the IBD group, a post hoc analysis identified that disease duration is associated with cortical complexity of the right supramarginal gyrus, albeit with a more lenient threshold applied.
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Doenças Inflamatórias Intestinais , Adulto , Humanos , Doenças Inflamatórias Intestinais/diagnóstico por imagem , Doenças Inflamatórias Intestinais/complicações , Encéfalo/diagnóstico por imagem , Neuroimagem , Lobo ParietalRESUMO
Background: Interoceptive signals related to changes in heartbeat, respiration, and gastric functioning continuously feedback to the brain. The interpretation of these signals influences several cognitive, affective, and motoric functions. Previous research has highlighted the distinction between the ability to accurately detect interoceptive information (i.e., interoceptive accuracy) and an individual's beliefs about his or her interoceptive abilities (i.e., interoceptive sensibility). Although numerous studies have delineated the neural substrates of interoceptive accuracy, less is known about the brain areas involved with interoceptive sensibility. Materials and Methods: In the current study, 28 healthy participants completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), a self-report measure of interoceptive sensibility, before undergoing a 7-min resting-state functional magnetic resonance imaging scan. IRB ethics approval was obtained prior to data collection. Results: Overall MAIA scores, as well as scores on its eight subscales, were entered as covariates in subsequent region-of-interest and independent-component analyses. These analyses yielded three key results. First, interoceptive sensibility was negatively correlated with the functional connectivity of visual regions. Second, the cerebellar resting-state network showed positive correlations with two MAIA subscales, suggesting that this structure plays a role in interoceptive functions. Finally, the functional connectivity of the insula, a structure critical for interoceptive accuracy, was not correlated with any of the MAIA scores. Conclusion: These results demonstrate that the brain areas associated with individual differences in interoceptive sensibility show relatively little overlap with those involved with the accurate detection of interoceptive information. Impact statement The current research demonstrates that individual differences in interoceptive sensibility (i.e., self-reported sensitivity to interoceptive information) are related to differences in resting-state functional connectivity. These data also indicate that the brain areas related to interoceptive sensibility are different than the brain areas involved with interoceptive accuracy (i.e., the objective detection of interoceptive signals). This latter finding suggests that although the insula is critical for many interoceptive processes, our subjective beliefs about our interoceptive abilities involve other neural structures, particularly visual regions and the cerebellum.
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Interocepção , Conscientização , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
Objective: Vascular comorbidities are associated with reduced cognitive performance and with changes in brain structure in people with multiple sclerosis (MS). Understanding causal pathways is necessary to support the design of interventions to mitigate the impacts of comorbidities, and to monitor their effectiveness. We assessed the inter-relationships among vascular comorbidity, cognition and brain structure in people with MS. Methods: Adults with neurologist-confirmed MS reported comorbidities, and underwent assessment of their blood pressure, HbA1c, and cognitive functioning (i.e., Symbol Digit Modalities Test, California Verbal Learning Test, Brief Visuospatial Memory Test-Revised, and verbal fluency). Test scores were converted to age-, sex-, and education-adjusted z-scores. Whole brain magnetic resonance imaging (MRI) was completed, from which measures of thalamic and hippocampal volumes, and mean diffusivity of gray matter and normal-appearing white matter were converted to age and sex-adjusted z-scores. Canonical correlation analysis was used to identify linear combinations of cognitive measures (cognitive variate) and MRI measures (MRI variate) that accounted for the most correlation between the cognitive and MRI measures. Regression analyses were used to test whether MRI measures mediated the relationships between the number of vascular comorbidities and cognition measures. Results: Of 105 participants, most were women (84.8%) with a mean (SD) age of 51.8 (12.8) years and age of symptom onset of 29.4 (10.5) years. Vascular comorbidity was common, with 35.2% of participants reporting one, 15.2% reporting two, and 8.6% reporting three or more. Canonical correlation analysis of the cognitive and MRI variables identified one pair of variates (Pillai's trace = 0.45, p = 0.0035). The biggest contributors to the cognitive variate were the SDMT and CVLT-II, and to the MRI variate were gray matter MD and thalamic volume. The correlation between cognitive and MRI variates was 0.50; these variates were used in regression analyses. On regression analysis, vascular comorbidity was associated with the MRI variate, and with the cognitive variate. After adjusting for the MRI variate, vascular comorbidity was not associated with the cognitive variate. Conclusion: Vascular comorbidity is associated with lower cognitive function in people with MS and this association is partially mediated via changes in brain macrostructure and microstructure.
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The Comorbidity and Cognition in Multiple Sclerosis (CCOMS) study represents a coordinated effort by a team of clinicians, neuropsychologists, and neuroimaging experts to investigate the neural basis of cognitive changes and their association with comorbidities among persons with multiple sclerosis (MS). The objectives are to determine the relationships among psychiatric (e.g., depression or anxiety) and vascular (e.g., diabetes, hypertension, etc.) comorbidities, cognitive performance, and MRI measures of brain structure and function, including changes over time. Because neuroimaging forms the basis for several investigations of specific neural correlates that will be reported in future publications, the goal of the current manuscript is to briefly review the CCOMS study design and baseline characteristics for participants enrolled in the three study cohorts (MS, psychiatric control, and healthy control), and provide a detailed description of the MRI hardware, neuroimaging acquisition parameters, and image processing pipelines for the volumetric, microstructural, functional, and perfusion MRI data.
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Previous research has demonstrated that emotional stimuli receive preferential processing in the brain. In the current study, functional magnetic resonance imaging was utilized to determine if emotion-specific responses are detectable in the cervical spinal cord. During the passive (i.e., non-motoric) perception of images, activity was detected in the left dorsal and right ventral spinal cord in response to negative emotional stimuli; however, this pattern was reversed in response to neutral and positive stimuli. Critically, during active motoric responses to images, there was greater activity in the ventral cervical spinal cord in response to negative emotional stimuli than to neutral stimuli. These results demonstrate preferential motor responses to negative emotional images by the spinal cord, likely indicating an enhancement of activity in response to threat.
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Emoções/fisiologia , Neurônios/fisiologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Interpretação Estatística de Dados , Medo/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Movimento/fisiologia , Percepção/fisiologia , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto JovemRESUMO
Fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) are commonly used as MRI biomarkers of white matter microstructure in diffusion MRI studies of neurodevelopment, brain aging, and neurologic injury/disease. Some of the more frequent practices include performing voxel-wise or region-based analyses of these measures to cross-sectionally compare individuals or groups, longitudinally assess individuals or groups, and/or correlate with demographic, behavioral or clinical variables. However, it is now widely recognized that the majority of cerebral white matter voxels contain multiple fiber populations with different trajectories, which renders these metrics highly sensitive to the relative volume fractions of the various fiber populations, the microstructural integrity of each constituent fiber population, and the interaction between these factors. Many diffusion imaging experts are aware of these limitations and now generally avoid using FA, AD or RD (at least in isolation) to draw strong reverse inferences about white matter microstructure, but based on the continued application and interpretation of these metrics in the broader biomedical/neuroscience literature, it appears that this has perhaps not yet become common knowledge among diffusion imaging end-users. Therefore, this paper will briefly discuss the complex biophysical underpinnings of these measures in the context of crossing fibers, provide some intuitive "thought experiments" to highlight how conventional interpretations can lead to incorrect conclusions, and suggest that future studies refrain from using (over-interpreting) FA, AD, and RD values as standalone biomarkers of cerebral white matter microstructure.
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OBJECTIVE: We aimed to identify differences in network properties of white matter microstructure between asymptomatic ulcerative colitis (UC) participants who had a history of chronic gut inflammation, healthy controls (HCs) and a disease control group without gut inflammation (irritable bowel syndrome; IBS). DESIGN: Diffusion weighted imaging was conducted in age and sex-matched participants with UC, IBS, and HCs (N = 74 each), together with measures of gastrointestinal and psychological symptom severity. Using streamline connectivity matrices and graph theory, we aimed to quantify group differences in brain network connectivity. Regions showing group connectivity differences were correlated with measures showing group behavioral and clinical differences. RESULTS: UC participants exhibited greater centrality in regions of the somatosensory network and default mode network, but lower centrality in the posterior insula and globus pallidus compared to HCs (q < 0.05). Hub analyses revealed compromised hubness of the pallidus in UC and IBS compared to HCs which was replaced by increased hubness of the postcentral sulcus. Surprisingly, few differences in network matrices between UC and IBS were identified. In UC, centrality measures in the secondary somatosensory cortex were associated with depression (q < 0.03), symptom related anxiety (q < 0.04), trait anxiety (q < 0.03), and symptom duration (q < 0.05). CONCLUSION: A history of UC is associated with neuroplastic changes in several brain networks, which are associated with symptoms of depression, trait and symptom-related anxiety, as well as symptom duration. When viewed together with the results from IBS subjects, these findings suggest that chronic gut inflammation as well as abdominal pain have a lasting impact on brain network organization, which may play a role in symptoms reported by UC patients, even when gut inflammation has subsided.
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Encéfalo , Síndrome do Intestino Irritável , Encéfalo/diagnóstico por imagem , Humanos , Inflamação , Síndrome do Intestino Irritável/diagnóstico por imagem , Plasticidade Neuronal , Córtex SomatossensorialRESUMO
OBJECTIVE: Childhood maltreatment is associated with pain catastrophizing. Both childhood maltreatment and pain catastrophizing are prevalent in certain immune-mediated inflammatory disease (IMID) populations. However, it is unknown whether childhood maltreatment contributes to the high rates of pain catastrophizing in IMID cohorts. We assessed the relationship between childhood maltreatment and pain catastrophizing in individuals with IMID, and whether this differed across IMID. METHODS: Between November 2014 and July 2016 we recruited individuals with multiple sclerosis (MS), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA). Participants completed the Childhood Trauma Questionnaire-Short Form, the Pain Catastrophizing Scale, and Hospital Anxiety and Depression Scale. We tested the association between childhood maltreatment and pain catastrophizing using multivariable logistic regression. RESULTS: We included 577 individuals with IMID (MS: 232, IBD: 215, RA: 130). Overall, 265 (46%) participants with IMID reported any childhood maltreatment, with the most common type of maltreatment being emotional neglect. Childhood maltreatment was associated with pain catastrophizing (OR 3.32; 95% CI 1.89-5.85) independent of other risk factors, including sociodemographics and symptoms of anxiety and depression. CONCLUSION: Pain catastrophizing is highly prevalent in our IMID population, and strongly associated with childhood maltreatment in this population. Interventions that consider childhood maltreatment and pain catastrophizing should be incorporated into the clinical management of IMID patients.