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1.
Proc Natl Acad Sci U S A ; 119(23): e2106244119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35639696

RESUMO

This current study aimed to investigate the impact of drum training on behavior and brain function in autistic adolescents with no prior drumming experience. Thirty-six autistic adolescents were recruited and randomly assigned to one of two groups. The drum group received individual drum tuition (two lessons per week over an 8-wk period), while the control group did not. All participants attended a testing session before and after the 8-wk period. Each session included a drumming assessment, an MRI scan, and a parent completing questionnaires relating to the participants' behavioral difficulties. Results showed that improvements in drumming performance were associated with a significant reduction in hyperactivity and inattention difficulties in drummers compared to controls. The fMRI results demonstrated increased functional connectivity in brain areas responsible for inhibitory control, action outcomes monitoring, and self-regulation. In particular, seed-to-voxel analyses revealed an increased functional connectivity in the right inferior frontal gyrus and the right dorsolateral prefrontal cortex. A multivariate pattern analysis demonstrated significant changes in the medial frontal cortex, the left and right paracingulate cortex, the subcallosal cortex, the left frontal pole, the caudate, and the left nucleus accumbens. In conclusion, this study investigates the impact of a drum-based intervention on neural and behavioral outcomes in autistic adolescents. We hope that these findings will inform further research and trials into the potential use of drum-based interventions in benefitting clinical populations with inhibition-related disorders and emotional and behavioral difficulties.


Assuntos
Transtorno Autístico , Música , Fenômenos Fisiológicos do Sistema Nervoso , Adolescente , Transtorno Autístico/terapia , Encéfalo , Criança , Emoções , Humanos , Aprendizagem , Musicoterapia , Agitação Psicomotora
2.
Hum Brain Mapp ; 45(2): e26600, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38339896

RESUMO

Resting functional magnetic resonance imaging (fMRI) studies have identified intrinsic spinal cord activity, which forms organised motor (ventral) and sensory (dorsal) resting-state networks. However, to facilitate the use of spinal fMRI in, for example, clinical studies, it is crucial to first assess the reliability of the method, particularly given the unique anatomical, physiological, and methodological challenges associated with acquiring the data. Here, we characterise functional connectivity relationships in the cervical cord and assess their between-session test-retest reliability in 23 young healthy volunteers. Resting-state networks were estimated in two ways (1) by estimating seed-to-voxel connectivity maps and (2) by calculating seed-to-seed correlations. Seed regions corresponded to the four grey matter horns (ventral/dorsal and left/right) of C5-C8 segmental levels. Test-retest reliability was assessed using the intraclass correlation coefficient. Spatial overlap of clusters derived from seed-to-voxel analysis between sessions was examined using Dice coefficients. Following seed-to-voxel analysis, we observed distinct unilateral dorsal and ventral organisation of cervical spinal resting-state networks that was largely confined in the rostro-caudal extent to each spinal segmental level, with more sparse connections observed between segments. Additionally, strongest correlations were observed between within-segment ipsilateral dorsal-ventral connections, followed by within-segment dorso-dorsal and ventro-ventral connections. Test-retest reliability of these networks was mixed. Reliability was poor when assessed on a voxelwise level, with more promising indications of reliability when examining the average signal within clusters. Reliability of correlation strength between seeds was highly variable, with the highest reliability achieved in ipsilateral dorsal-ventral and dorso-dorsal/ventro-ventral connectivity. However, the spatial overlap of networks between sessions was excellent. We demonstrate that while test-retest reliability of cervical spinal resting-state networks is mixed, their spatial extent is similar across sessions, suggesting that these networks are characterised by a consistent spatial representation over time.


Assuntos
Medula Cervical , Animais , Humanos , Medula Cervical/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Medula Espinal/diagnóstico por imagem , Substância Cinzenta , Encéfalo/patologia
3.
Ann Neurol ; 94(5): 873-884, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37466404

RESUMO

OBJECTIVE: Neuropharmacological changes in visual snow syndrome (VSS) are poorly understood. We aimed to use receptor target maps combined with resting functional magnetic resonance imaging (fMRI) data to identify which neurotransmitters might modulate brain circuits involved in VSS. METHODS: We used Receptor-Enriched Analysis of Functional Connectivity by Targets (REACT) to estimate and compare the molecular-enriched functional networks related to 5 neurotransmitter systems of patients with VSS (n = 24), healthy controls (HCs; n = 24), and migraine patients ([MIG], n = 25, 15 of whom had migraine with aura [MwA]). For REACT we used receptor density templates for the transporters of noradrenaline, dopamine, and serotonin, GABA-A and NMDA receptors, as well as 5HT1B and 5HT2A receptors, and estimated the subject-specific voxel-wise maps of functional connectivity (FC). We then performed voxel-wise comparisons of these maps among HCs, MIG, and VSS. RESULTS: Patients with VSS had reduced FC in glutamatergic networks localized in the anterior cingulate cortex (ACC) compared to HCs and patients with migraine, and reduced FC in serotoninergic networks localized in the insula, temporal pole, and orbitofrontal cortex compared to controls, similar to patients with migraine with aura. Patients with VSS also showed reduced FC in 5HT2A -enriched networks, largely localized in occipito-temporo-parietal association cortices. As revealed by subgroup analyses, these changes were independent of, and analogous to, those found in patients with migraine with aura. INTERPRETATION: Our results show that glutamate and serotonin are involved in brain connectivity alterations in areas of the visual, salience, and limbic systems in VSS. Importantly, altered serotonergic connectivity is independent of migraine in VSS, and simultaneously comparable to that of migraine with aura, highlighting a shared biology between the disorders. ANN NEUROL 2023;94:873-884.


Assuntos
Enxaqueca com Aura , Humanos , Enxaqueca com Aura/diagnóstico por imagem , Serotonina , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem
4.
Hum Brain Mapp ; 44(5): 1901-1912, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36546653

RESUMO

The identification of meaningful functional magnetic resonance imaging (fMRI) biomarkers requires measures that reliably capture brain performance across different subjects and over multiple scanning sessions. Recent developments in fMRI acquisition, such as the introduction of multiband (MB) protocols and in-plane acceleration, allow for increased scanning speed and improved temporal resolution. However, they may also lead to reduced temporal signal to noise ratio and increased signal leakage between simultaneously excited slices. These methods have been adopted in several scanning modalities including diffusion weighted imaging and fMRI. To our knowledge, no study has formally compared the reliability of the same resting-state fMRI (rs-fMRI) metrics (amplitude of low-frequency fluctuations; seed-to-voxel and region of interest [ROI]-to-ROI connectivity) across conventional single-band fMRI and different MB acquisitions, with and without in-plane acceleration, across three sessions. In this study, 24 healthy older adults were scanned over three visits, on weeks 0, 1, and 4, and, on each occasion, underwent a conventional single band rs-fMRI scan and three different rs-fMRI scans with MB factors 4 and 6, with and without in-plane acceleration. Across all three rs-fMRI metrics, the reliability scores were highest with MB factor 4 with no in-plane acceleration for cortical areas and with conventional single band for subcortical areas. Recommendations for future research studies are discussed.


Assuntos
Mapeamento Encefálico , Envelhecimento Saudável , Humanos , Idoso , Mapeamento Encefálico/métodos , Reprodutibilidade dos Testes , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
5.
Psychol Med ; 53(7): 2831-2841, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-34852855

RESUMO

BACKGROUND: Overgeneralised self-blame and worthlessness are key symptoms of major depressive disorder (MDD) and have previously been associated with self-blame-selective changes in connectivity between right superior anterior temporal lobe (rSATL) and subgenual frontal cortices. Another study showed that remitted MDD patients were able to modulate this neural signature using functional magnetic resonance imaging (fMRI) neurofeedback training, thereby increasing their self-esteem. The feasibility and potential of using this approach in symptomatic MDD were unknown. METHOD: This single-blind pre-registered randomised controlled pilot trial probed a novel self-guided psychological intervention with and without additional rSATL-posterior subgenual cortex (BA25) fMRI neurofeedback, targeting self-blaming emotions in people with insufficiently recovered MDD and early treatment-resistance (n = 43, n = 35 completers). Participants completed three weekly self-guided sessions to rebalance self-blaming biases. RESULTS: As predicted, neurofeedback led to a training-induced reduction in rSATL-BA25 connectivity for self-blame v. other-blame. Both interventions were safe and resulted in a 46% reduction on the Beck Depression Inventory-II, our primary outcome, with no group differences. Secondary analyses, however, revealed that patients without DSM-5-defined anxious distress showed a superior response to neurofeedback compared with the psychological intervention, and the opposite pattern in anxious MDD. As predicted, symptom remission was associated with increases in self-esteem and this correlated with the frequency with which participants employed the psychological strategies in daily life. CONCLUSIONS: These findings suggest that self-blame-rebalance neurofeedback may be superior over a solely psychological intervention in non-anxious MDD, although further confirmatory studies are needed. Simple self-guided strategies tackling self-blame were beneficial, but need to be compared against treatment-as-usual in further trials. https://doi.org/10.1186/ISRCTN10526888.


Assuntos
Transtorno Depressivo Maior , Neurorretroalimentação , Humanos , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/terapia , Transtorno Depressivo Maior/patologia , Projetos Piloto , Neurorretroalimentação/métodos , Depressão , Imageamento por Ressonância Magnética , Método Simples-Cego
6.
Hum Brain Mapp ; 43(17): 5235-5249, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35796178

RESUMO

Arterial spin labelling (ASL) plays an increasingly important role in neuroimaging pain research but does not provide molecular insights regarding how regional cerebral blood flow (rCBF) relates to underlying neurotransmission. Here, we integrate ASL with positron emission tomography (PET) and brain transcriptome data to investigate the molecular substrates of rCBF underlying clinically relevant pain states. Two data sets, representing acute and chronic ongoing pain respectively, were utilised to quantify changes in rCBF; one examining pre-surgical versus post-surgical pain, and the second comparing patients with painful hand Osteoarthritis to a group of matched controls. We implemented a whole-brain spatial correlation analysis to explore associations between change in rCBF (ΔCBF) and neurotransmitter receptor distributions derived from normative PET templates. Additionally, we utilised transcriptomic data from the Allen Brain Atlas to inform distributions of receptor expression. Both datasets presented significant correlations of ΔCBF with the µ-opioid and dopamine-D2 receptor expressions, which play fundamental roles in brain activity associated with pain experiences. ΔCBF also correlated with the gene expression distributions of several receptors involved in pain processing. Overall, this is the first study illustrating the molecular basis of ongoing pain ASL indices and emphasises the potential of rCBF as a biomarker in pain research.


Assuntos
Circulação Cerebrovascular , Dor Crônica , Humanos , Circulação Cerebrovascular/fisiologia , Marcadores de Spin , Tomografia por Emissão de Pósitrons , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Imageamento por Ressonância Magnética/métodos , Fluxo Sanguíneo Regional
7.
Hum Brain Mapp ; 43(5): 1749-1765, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34953014

RESUMO

Current neuroimaging acquisition and processing approaches tend to be optimised for quality rather than speed. However, rapid acquisition and processing of neuroimaging data can lead to novel neuroimaging paradigms, such as adaptive acquisition, where rapidly processed data is used to inform subsequent image acquisition steps. Here we first evaluate the impact of several processing steps on the processing time and quality of registration of manually labelled T1 -weighted MRI scans. Subsequently, we apply the selected rapid processing pipeline both to rapidly acquired multicontrast EPImix scans of 95 participants (which include T1 -FLAIR, T2 , T2 *, T2 -FLAIR, DWI and ADC contrasts, acquired in ~1 min), as well as to slower, more standard single-contrast T1 -weighted scans of a subset of 66 participants. We quantify the correspondence between EPImix T1 -FLAIR and single-contrast T1 -weighted scans, using correlations between voxels and regions of interest across participants, measures of within- and between-participant identifiability as well as regional structural covariance networks. Furthermore, we explore the use of EPImix for the rapid construction of morphometric similarity networks. Finally, we quantify the reliability of EPImix-derived data using test-retest scans of 10 participants. Our results demonstrate that quantitative information can be derived from a neuroimaging scan acquired and processed within minutes, which could further be used to implement adaptive multimodal imaging and tailor neuroimaging examinations to individual patients.


Assuntos
Encéfalo , Neuroimagem , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal , Neuroimagem/métodos , Reprodutibilidade dos Testes
8.
Hum Brain Mapp ; 43(10): 3207-3220, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35393717

RESUMO

In posttraumatic stress disorder (PTSD), re-experiencing of the trauma is a hallmark symptom proposed to emerge from a de-contextualised trauma memory. Cognitive therapy for PTSD (CT-PTSD) addresses this de-contextualisation through different strategies. At the brain level, recent research suggests that the dynamics of specific large-scale brain networks play an essential role in both the healthy response to a threatening situation and the development of PTSD. However, very little is known about how these dynamics are altered in the disorder and rebalanced after treatment and successful recovery. Using a data-driven approach and fMRI, we detected recurring large-scale brain functional states with high temporal precision in a population of healthy trauma-exposed and PTSD participants before and after successful CT-PTSD. We estimated the total amount of time that each participant spent on each of the states while being exposed to trauma-related and neutral pictures. We found that PTSD participants spent less time on two default mode subnetworks involved in different forms of self-referential processing in contrast to PTSD participants after CT-PTSD (mtDMN+ and dmDMN+ ) and healthy trauma-exposed controls (only mtDMN+ ). Furthermore, re-experiencing severity was related to decreased time spent on the default mode subnetwork involved in contextualised retrieval of autobiographical memories, and increased time spent on the salience and visual networks. Overall, our results support the hypothesis that PTSD involves an imbalance in the dynamics of specific large-scale brain network states involved in self-referential processes and threat detection, and suggest that successful CT-PTSD might rebalance this dynamic aspect of brain function.


Assuntos
Memória Episódica , Transtornos de Estresse Pós-Traumáticos , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Transtornos de Estresse Pós-Traumáticos/diagnóstico por imagem , Transtornos de Estresse Pós-Traumáticos/terapia
9.
Hum Brain Mapp ; 43(1): 431-451, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33595143

RESUMO

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large-scale studies. In response, we used cross-sectional data from 17,075 individuals aged 3-90 years from the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to infer age-related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta-analysis and one-way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes.


Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Desenvolvimento Humano/fisiologia , Neuroimagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Magn Reson Med ; 88(3): 1273-1281, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35553454

RESUMO

PURPOSE: Low magnetic field systems provide an important opportunity to expand MRI to new and diverse clinical and research study populations. However, a fundamental limitation of low field strength systems is the reduced SNR compared to 1.5 or 3T, necessitating compromises in spatial resolution and imaging time. Most often, images are acquired with anisotropic voxels with low through-plane resolution, which provide acceptable image quality with reasonable scan times, but can impair visualization of subtle pathology. METHODS: Here, we describe a super-resolution approach to reconstruct high-resolution isotropic T2 -weighted images from a series of low-resolution anisotropic images acquired in orthogonal orientations. Furthermore, acquiring each image with an incremented TE allows calculations of quantitative T2 images without time penalty. RESULTS: Our approach is demonstrated via phantom and in vivo human brain imaging, with simultaneous 1.5 × 1.5 × 1.5 mm3 T2 -weighted and quantitative T2 maps acquired using a clinically feasible approach that combines three acquisition that require approximately 4-min each to collect. Calculated T2 values agree with reference multiple TE measures with intraclass correlation values of 0.96 and 0.85 in phantom and in vivo measures, respectively, in line with previously reported brain T2 values at 150 mT, 1.5T, and 3T. CONCLUSION: Our multi-orientation and multi-TE approach is a time-efficient method for high-resolution T2 -weighted images for anatomical visualization with simultaneous quantitative T2 imaging for increased sensitivity to tissue microstructure and chemical composition.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Humanos , Campos Magnéticos , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas
11.
Magn Reson Med ; 88(1): 195-210, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35381110

RESUMO

PURPOSE: To develop self-navigated motion correction for 3D silent zero echo time (ZTE) based neuroimaging and characterize its performance for different types of head motion. METHODS: The proposed method termed MERLIN (Motion Estimation & Retrospective correction Leveraging Interleaved Navigators) achieves self-navigation by using interleaved 3D phyllotaxis k-space sampling. Low resolution navigator images are reconstructed continuously throughout the ZTE acquisition using a sliding window and co-registered in image space relative to a fixed reference position. Rigid body motion corrections are then applied retrospectively to the k-space trajectory and raw data and reconstructed into a final, high-resolution ZTE image. RESULTS: MERLIN demonstrated successful and consistent motion correction for magnetization prepared ZTE images for a range of different instructed motion paradigms. The acoustic noise response of the self-navigated phyllotaxis trajectory was found to be only slightly above ambient noise levels (<4 dBA). CONCLUSION: Silent ZTE imaging combined with MERLIN addresses two major challenges intrinsic to MRI (i.e., subject motion and acoustic noise) in a synergistic and integrated manner without increase in scan time and thereby forms a versatile and powerful framework for clinical and research MR neuroimaging applications.


Assuntos
Imageamento por Ressonância Magnética , Neurofibromina 2 , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Movimento (Física) , Neuroimagem , Estudos Retrospectivos
12.
Neuroimage ; 238: 118273, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34146712

RESUMO

Magnetic resonance imaging (MRI) has played an increasingly relevant role in understanding infant, child, and adolescent neurodevelopment, providing new insight into developmental patterns in neurotypical development, as well as those associated with potential psychopathology, learning disorders, and other neurological conditions. In addition, studies have shown the impact of a child's physical and psychosocial environment on developing brain structure and function. A rate-limiting complication in these studies, however, is the high cost and infrastructural requirements of modern MRI systems. High costs mean many neuroimaging studies typically include fewer than 100 individuals and are performed predominately in high resource hospitals and university settings within high income countries (HICs). As a result, our knowledge of brain development, particularly in children who live in lower and middle income countries (LMICs) is relatively limited. Low field systems, with magnetic fields less than 100mT offer the promise of lower scanning costs and wide-spread global adoption, but routine low field pediatric neuroimaging has yet to be demonstrated. Here we present the first pediatric MRI data collected on a low cost and assessable 64mT scanner in children 6 weeks to 16 years of age and replicate brain volumes estimates and developmental trajectories derived from 3T MRI data. While preliminary, these results illustrate the potential of low field imaging as a viable complement to more conventional high field imaging systems, and one that may further enhance our knowledge of neurodevelopment in LMICs where malnutrition, psychosocial adversities, and other environmental exposures may profoundly affect brain maturation.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/instrumentação , Neuroimagem/métodos , Adolescente , Criança , Humanos , Pediatria
13.
Hum Brain Mapp ; 42(16): 5495-5518, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34414633

RESUMO

Startle reflex is modulated when a weaker sensory stimulus ("prepulse") precedes a startling stimulus ("pulse"). Prepulse Inhibition (PPI) is the attenuation of the startle reflex (prepulse precedes pulse by 30-500 ms), whereas Prepulse Facilitation (PPF) is the enhancement of the startle reflex (prepulse precedes pulse by 500-6000 ms). Here, we critically appraise human studies using functional neuroimaging to establish brain regions associated with PPI and PPF. Of 10 studies, nine studies revealed thalamic, striatal and frontal lobe activation during PPI in healthy groups, and activation deficits in the cortico-striato-pallido-thalamic circuitry in schizophrenia (three studies) and Tourette Syndrome (two studies). One study revealed a shared network for PPI and PPF in frontal regions and cerebellum, with PPF networks recruiting superior medial gyrus and cingulate cortex. The main gaps in the literature are (i) limited PPF research and whether PPI and PPF operate on separate/shared networks, (ii) no data on sex differences in neural underpinnings of PPI and PPF, and (iii) no data on neural underpinnings of PPI and PPF in other clinical disorders.


Assuntos
Neuroimagem Funcional , Percepção/fisiologia , Inibição Pré-Pulso/fisiologia , Reflexo de Sobressalto/fisiologia , Esquizofrenia/fisiopatologia , Sensação/fisiologia , Síndrome de Tourette/fisiopatologia , Humanos , Esquizofrenia/diagnóstico por imagem , Síndrome de Tourette/diagnóstico por imagem
14.
Hum Brain Mapp ; 42(9): 2833-2850, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33729637

RESUMO

Looping Star is a near-silent, multi-echo, 3D functional magnetic resonance imaging (fMRI) technique. It reduces acoustic noise by at least 25dBA, with respect to gradient-recalled echo echo-planar imaging (GRE-EPI)-based fMRI. Looping Star has successfully demonstrated sensitivity to the cerebral blood-oxygen-level-dependent (BOLD) response during block design paradigms but has not been applied to event-related auditory perception tasks. Demonstrating Looping Star's sensitivity to such tasks could (a) provide new insights into auditory processing studies, (b) minimise the need for invasive ear protection, and (c) facilitate the translation of numerous fMRI studies to investigations in sound-averse patients. We aimed to demonstrate, for the first time, that multi-echo Looping Star has sufficient sensitivity to the BOLD response, compared to that of GRE-EPI, during a well-established event-related auditory discrimination paradigm: the "oddball" task. We also present the first quantitative evaluation of Looping Star's test-retest reliability using the intra-class correlation coefficient. Twelve participants were scanned using single-echo GRE-EPI and multi-echo Looping Star fMRI in two sessions. Random-effects analyses were performed, evaluating the overall response to tones and differential tone recognition, and intermodality analyses were computed. We found that multi-echo Looping Star exhibited consistent sensitivity to auditory stimulation relative to GRE-EPI. However, Looping Star demonstrated lower test-retest reliability in comparison with GRE-EPI. This could reflect differences in functional sensitivity between the techniques, though further study is necessary with additional cognitive paradigms as varying cognitive strategies between sessions may arise from elimination of acoustic scanner noise.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Discriminação Psicológica/fisiologia , Neuroimagem Funcional/normas , Imageamento por Ressonância Magnética/normas , Adulto , Córtex Auditivo/diagnóstico por imagem , Imagem Ecoplanar/métodos , Imagem Ecoplanar/normas , Feminino , Neuroimagem Funcional/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Ruído
15.
Psychol Med ; 51(10): 1724-1732, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32174288

RESUMO

BACKGROUND: Postpartum psychosis (PP) is a severe postpartum disorder. While working memory and emotional processing-related brain function are consistently impaired in psychoses unrelated to the puerperium, no studies have investigated them in PP. METHODS: Twenty-four women at risk of developing PP (11 developed an episode - PE; 13 remained well - NPE) and 20 healthy postpartum women completed two functional magnetic resonance imaging tasks within a year of delivery: working memory (n-back) and emotional face recognition (fearful faces). We compared women at-risk of PP to controls, as well as NPE, PE, and controls to test for potential effects of a PP episode occurrence. RESULTS: Women at-risk of PP and PE showed hyperactivation of lateral visual areas, precuneus, and posterior cingulate during the n-back task. The at-risk group as a whole, as well as the PE and NPE groups, showed hyperconnectivity of the right dorsolateral prefrontal cortex (DLPFC) with various parieto-occipito-temporo-cerebellar regions compared to controls during several n-back conditions. Increases in connectivity between the right DLPFC and ipsilateral middle temporal gyrus were observed in the PE group compared to NPE during 2-back. During the fearful faces task, at-risk women as a group showed hyperactivation of fronto-cingulo-subcortical regions, and hypoconnectivity between the left amygdala and ipsilateral occipito-parietal regions compared to controls. No significant performance differences were observed. CONCLUSIONS: These results present preliminary evidence of a differential nature of functional brain abnormalities in PP compared to the typically observed reduced connectivity with the DLPFC in psychoses unrelated to puerperium, such as bipolar disorder.


Assuntos
Encéfalo/fisiopatologia , Emoções/fisiologia , Reconhecimento Facial/fisiologia , Memória de Curto Prazo/fisiologia , Período Pós-Parto/psicologia , Transtornos Psicóticos/fisiopatologia , Adulto , Transtorno Bipolar/fisiopatologia , Cognição/fisiologia , Córtex Pré-Frontal Dorsolateral , Feminino , Giro do Cíngulo/fisiopatologia , Humanos , Londres , Imageamento por Ressonância Magnética , Lobo Parietal/fisiopatologia , Transtornos Psicóticos/diagnóstico
16.
Magn Reson Med ; 84(2): 813-824, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31961961

RESUMO

PURPOSE: To compare the silent rotating ultrafast imaging sequence (RUFIS) to a traditional Cartesian spoiled gradient-echo (SPGR) acquisition scheme for variable flip angle (VFA) T1 mapping. METHODS: A two-point VFA measurement was performed using RUFIS and Cartesian SPGR in a quantitative phantom and healthy volunteers. To correct for B1 errors, a novel silent magnetization prepared B1 map acquisition (SIMBA) was developed, which combined with RUFIS VFA allows for a completely silent T1 mapping protocol. RESULTS: The silent protocol was found to have comparable repeatability but higher reproducibility in vivo compared to the standard SPGR protocol, and showed no increase in acoustic noise levels above background noise levels compared to a 33 dBA increase for the SPGR acquisition. CONCLUSIONS: VFA T1 mapping using RUFIS is a feasible alternative to SPGR, achieving silent T1 mapping with comparable acquisition time.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Algoritmos , Voluntários Saudáveis , Humanos , Imagens de Fantasmas , Reprodutibilidade dos Testes
17.
Ann Neurol ; 85(1): 32-46, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30525223

RESUMO

OBJECTIVE: Neurotrophin-3 (NT3) plays a key role in the development and function of locomotor circuits including descending serotonergic and corticospinal tract axons and afferents from muscle and skin. We have previously shown that gene therapy delivery of human NT3 into affected forelimb muscles improves sensorimotor recovery after stroke in adult and elderly rats. Here, to move toward the clinic, we tested the hypothesis that intramuscular infusion of NT3 protein could improve sensorimotor recovery after stroke. METHODS: Rats received unilateral ischemic stroke in sensorimotor cortex. To simulate a clinically feasible time to treatment, 24 hours later rats were randomized to receive NT3 or vehicle by infusion into affected triceps brachii for 4 weeks using implanted catheters and minipumps. RESULTS: Radiolabeled NT3 crossed from the bloodstream into the brain and spinal cord in rodents with or without strokes. NT3 increased the accuracy of forelimb placement during walking on a horizontal ladder and increased use of the affected arm for lateral support during rearing. NT3 also reversed sensory impairment of the affected wrist. Functional magnetic resonance imaging during stimulation of the affected wrist showed spontaneous recovery of peri-infarct blood oxygenation level-dependent signal that NT3 did not further enhance. Rather, NT3 induced neuroplasticity of the spared corticospinal and serotonergic pathways. INTERPRETATION: Our results show that delayed, peripheral infusion of NT3 can improve sensorimotor function after ischemic stroke. Phase I and II clinical trials of NT3 (for constipation and neuropathy) have shown that peripheral high doses are safe and well tolerated, which paves the way for NT3 as a therapy for stroke. ANN NEUROL 2019;85:32-46.


Assuntos
Neurotrofina 3/administração & dosagem , Recuperação de Função Fisiológica/efeitos dos fármacos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Feminino , Injeções Intramusculares , Distribuição Aleatória , Ratos , Recuperação de Função Fisiológica/fisiologia , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/efeitos dos fármacos , Córtex Sensório-Motor/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo
18.
Eur J Nucl Med Mol Imaging ; 47(2): 366-378, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31637481

RESUMO

PURPOSE: We evaluated myelin changes throughout the central nervous system in Multiple Sclerosis (MS) patients by using hybrid [18F]florbetapir PET-MR imaging. METHODS: We included 18 relapsing-remitting MS patients and 12 healthy controls. Each subject performed a hybrid [18F]florbetapir PET-MR and both a clinical and cognitive assessment. [18F]florbetapir binding was measured as distribution volume ratio (DVR), through the Logan graphical reference method and the supervised cluster analysis to extract a reference region, and standard uptake value (SUV) in the 70-90 min interval after injection. The two quantification approaches were compared. We also evaluated changes in the measures derived from diffusion tensor imaging and arterial spin labeling. RESULTS: [18F]florbetapir DVRs decreased from normal-appearing white matter to the centre of T2 lesion (P < 0.001), correlated with fractional anisotropy and with mean, axial and radial diffusivity within T2 lesions (coeff. = -0.15, P < 0.001, coeff. = -0.12, P < 0.001 and coeff. = -0.16, P < 0.001, respectively). Cerebral blood flow was reduced in white matter damaged areas compared to white matter in healthy controls (-10.9%, P = 0.005). SUV70-90 and DVR are equally able to discriminate between intact and damaged myelin (area under the curve 0.76 and 0.66, respectively; P = 0.26). CONCLUSION: Our findings demonstrate that [18F]florbetapir PET imaging can measure in-vivo myelin damage in patients with MS. Demyelination in MS is not restricted to lesions detected through conventional MRI but also involves the normal appearing white matter. Although longitudinal studies are needed, [18F]florbetapir PET imaging may have a role in clinical settings in the management of MS patients.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Substância Branca , Compostos de Anilina , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão , Etilenoglicóis , Humanos , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Substância Branca/diagnóstico por imagem
19.
J Physiol ; 597(6): 1517-1529, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30629751

RESUMO

KEY POINTS: Nausea is an adverse experience characterised by alterations in autonomic and cerebral function. Susceptibility to nausea is difficult to predict, but machine learning has yet to be applied to this field of study. The severity of nausea that individuals experience is related to the underlying morphology (shape) of the subcortex, namely of the amygdala, caudate and putamen; a functional brain network related to nausea severity was identified, which included the thalamus, cingulate cortices (anterior, mid- and posterior), caudate nucleus and nucleus accumbens. Sympathetic nervous system function and sympathovagal balance, by heart rate variability, was closely related to both this nausea-associated anatomical variation and the functional connectivity network, and machine learning accurately predicted susceptibility or resistance to nausea. These novel anatomical and functional brain biomarkers for nausea severity may permit objective identification of individuals susceptible to nausea, using artificial intelligence/machine learning; brain data may be useful to identify individuals more susceptible to nausea. ABSTRACT: Nausea is a highly individual and variable experience. The central processing of nausea remains poorly understood, although numerous influential factors have been proposed, including brain structure and function, as well as autonomic nervous system (ANS) activity. We investigated the role of these factors in nausea severity and if susceptibility to nausea could be predicted using machine learning. Twenty-eight healthy participants (15 males; mean age 24 years) underwent quantification of resting sympathetic and parasympathetic nervous system activity by heart rate variability. All were exposed to a 10-min motion-sickness video during fMRI. Neuroanatomical shape differences of the subcortex and functional brain networks associated with the severity of nausea were investigated. A machine learning neural network was trained to predict nausea susceptibility, or resistance, using resting ANS data and detected brain features. Increasing nausea scores positively correlated with shape variation of the left amygdala, right caudate and bilateral putamen (corrected P = 0.05). A functional brain network linked to increasing nausea severity was identified implicating the thalamus, anterior, middle and posterior cingulate cortices, caudate nucleus and nucleus accumbens (corrected P = 0.043). Both neuroanatomical differences and the functional nausea-brain network were closely related to sympathetic nervous system activity. Using these data, a machine learning model predicted susceptibility to nausea with an overall accuracy of 82.1%. Nausea severity relates to underlying subcortical morphology and a functional brain network; both measures are potential biomarkers in trials of anti-nausea therapies. The use of machine learning should be further investigated as an objective means to develop models predicting nausea susceptibility.


Assuntos
Encéfalo/fisiologia , Conectoma , Aprendizado de Máquina , Enjoo devido ao Movimento/fisiopatologia , Náusea/fisiopatologia , Adolescente , Adulto , Sistema Nervoso Autônomo/fisiologia , Sistema Nervoso Autônomo/fisiopatologia , Encéfalo/fisiopatologia , Feminino , Trato Gastrointestinal/inervação , Trato Gastrointestinal/fisiologia , Trato Gastrointestinal/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
20.
Neuroimage ; 188: 774-784, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30553916

RESUMO

As a result of neuro-vascular coupling, the functional effects of antipsychotics in human brain have been investigated in both healthy and clinical populations using haemodynamic markers such as regional Cerebral Blood Flow (rCBF). However, the relationship between observed haemodynamic effects and the pharmacological action of these drugs has not been fully established. Here, we analysed Arterial Spin Labelling (ASL) rCBF data from a placebo-controlled study in healthy volunteers, who received a single dose of three different D2 receptor (D2R) antagonists and tested the association of the main effects of the drugs on rCBF against normative population maps of D2R protein density and gene-expression data. In particular, we correlated CBF changes after antipsychotic administration with non-displaceable binding potential (BPND) template maps of the high affinity D2-antagonist Positron Emission Tomography (PET) ligand [18F]Fallypride and with brain post-mortem microarray mRNA expression data for the DRD2 gene from the Allen Human Brain Atlas (ABA). For all antipsychotics, rCBF changes were directly proportional to brain D2R densities and DRD2 mRNA expression measures, although PET BPND spatial profiles explained more variance as compared with mRNA profiles (PET R2 range = 0.20-0.60, mRNA PET R2 range 0.04-0.20, pairwise-comparisons all pcorrected<0.05). In addition, the spatial coupling between ΔCBF and D2R profiles varied between the different antipsychotics tested, possibly reflecting differential affinities. Overall, these results indicate that the functional effects of antipsychotics as measured with rCBF are tightly correlated with the distribution of their target receptors in striatal and extra-striatal regions. Our results further demonstrate the link between neurotransmitter targets and haemodynamic changes reinforcing rCBF as a robust in-vivo marker of drug effects. This work is important in bridging the gap between pharmacokinetic and pharmacodynamics of novel and existing compounds.


Assuntos
Antipsicóticos/farmacocinética , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Circulação Cerebrovascular/efeitos dos fármacos , Antagonistas dos Receptores de Dopamina D2/farmacocinética , Receptores de Dopamina D2/metabolismo , Adulto , Antipsicóticos/administração & dosagem , Benzamidas/farmacocinética , Encéfalo/diagnóstico por imagem , Estudos Cross-Over , Antagonistas dos Receptores de Dopamina D2/administração & dosagem , Método Duplo-Cego , Radioisótopos de Flúor , Haloperidol/farmacocinética , Voluntários Saudáveis , Humanos , Olanzapina/farmacocinética , Tomografia por Emissão de Pósitrons , RNA Mensageiro/metabolismo , Risperidona/farmacocinética , Marcadores de Spin
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