Default mode network functional connectivity after multiple concussions in children and adolescents

Abstract The default mode network (DMN), a set of brain regions, has been shown to be affected post-concussion. Objective This cross-sectional study aims to elucidate if children and adolescents with multiple concussions demonstrate long-term alterations in DMN functional connectivity (FC). Method Participants (N = 57, 27 girls and 30 boys; 8-19 years old, M age = 14.7, SD = 2.8) were divided into three groups (orthopedic injury [OI] n = 20; one concussion n = 16; multiple concussions n = 21, M = 3.2 concussions, SD = 1.7) and seen on average 31.6 months post-injury (range 4.3-130.7 months; SD = 19.4). They underwent a resting-state functional magnetic resonance imaging scan. Parents completed the ADHD rating scale-5 for children and adolescents. Children and parents completed the post-concussion symptom inventory (PCSI). Results Anterior and posterior DMN components were extracted from the fMRI data for each participant using FSL’s MELODIC and dual regression. We tested for pairwise group differences within each DMN component in FSL’s Randomize (5000 permutations) using threshold-free cluster enhancement to estimate cluster activation, controlling for age, sex, and symptoms of inattention. FC of the anterior DMN was significantly reduced in the group with multiple concussions compared to the two other groups, whereas there were no significant group differences on FC of the posterior DMN. There were no significant associations between DMN FC and PCSI scores. Conclusions These results suggest reduced FC in the anterior DMN in youth with multiple concussions, but no linear association with post-concussive symptoms.

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Altered cerebrocerebellar functional connectivity in patients with obstructive sleep apnea and its association with cognitive function

SLEEP ◽

10.1093/sleep/zsab209 ◽

2021 ◽

Author(s):

Hea Ree Park ◽

Jungho Cha ◽

Eun Yeon Joo ◽

Hosung Kim

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Functional Connectivity ◽

Functional Mri ◽

Default Mode Network ◽

Healthy Subjects ◽

Clustering Coefficient ◽

Significant Group ◽

Default Mode ◽

Obstructive Sleep

Abstract Study Objectives Previous functional MRI studies have reported altered brain networks in patients with obstructive sleep apnea (OSA). However, the extent and pattern of abnormal connectivity were inconsistent across studies, and cerebrocerebellar connections have been rarely assessed. We investigated functional network changes in cerebral and cerebellar cortices of OSA patients. Methods Resting-state functional MRI, polysomnography and neuropsychological (NP) test data were acquired from 74 OSA patients (age: 45.8±10.7 years) and 33 healthy subjects (39.6±9.3 years). Connectivity matrices were extracted by computing correlation coefficients from various ROIs, and Fisher r-to-z transformations. In the functional connections that showed significant group differences, linear regression was conducted to examine the association between connectivity and clinical characteristics. Results Patients with OSA showed reduced functional connectivity (FC) in cerebrocerebellar connections linking different functional networks, and greater FC in cortical between-network connections in prefrontal regions involving the default mode network and the control network. For OSA group, we found no correlation between FC and sleep parameters including lowest SaO2 and arousal index in the connections where significant associations were observed in healthy subjects. FC changes in default mode network (DMN) areas were related to reduced verbal fluency in OSA. Lower local efficiency and lower clustering coefficient of the salience network in the left cerebellum were also observed in OSA. Conclusions OSA affects mainly the cerebrocerebellar pathway. The disruption of function in these connections are related to sleep fragmentation and hypoxia during sleep. These abnormal network functions, especially DMN, are suggested to participate in cognitive decline of OSA.

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Peripheral inflammation is associated with micro-structural and functional connectivity changes in depression-related brain networks

10.1101/2020.09.09.20191262 ◽

2020 ◽

Author(s):

Manfred G Kitzbichler ◽

Athina R Aruldass ◽

Gareth J Barker ◽

Tobias C Wood ◽

Nicholas G Dowell ◽

...

Keyword(s):

Prefrontal Cortex ◽

Depressive Symptoms ◽

Functional Connectivity ◽

Default Mode Network ◽

Structural Parameters ◽

Brain Magnetic Resonance Imaging ◽

Peripheral Inflammation ◽

Micro Structure ◽

Significant Group ◽

Default Mode

Background: Peripheral inflammation is associated with depressive symptoms and innate immune mechanisms are likely causal for some patients with depression. However, it remains unclear how biomarkers of inflammation in the blood, e.g., C-reactive protein (CRP), relate to the changes in brain micro-structure and function that are hypothesised to mediate effects on depression. Methods: Here, we recruited N=46 healthy controls and N=83 patients with major depressive disorder (MDD), divided into high CRP (>3mg/L; N=33) and low CRP groups (<3mg/L; N=50). All participants completed a clinical assessment, venous blood sampling for CRP, and brain magnetic resonance imaging (MRI). A set of micro-structural parameters including proton density (PD) were estimated at 360 cortical and 16 subcortical regions and fMRI time series correlations used to measure inter-regional functional connectivity and regional weighted degree. Results are reported at stringent whole brain FDR correction (p<0.05). Results: Across participants, CRP showed a significant positive correlation with PD within precuneus / posterior cingulate cortex (pC/pCC) and medial prefrontal cortex (mPFC) and a converse negative correlation within dorsolateral prefrontal cortex (DLPFC). No significant group differences were observed. Functional connectivity analyses demonstrated significant case-control differences centred almost exclusively on the default mode network (DMN), with significantly reduced nodal degree within pC/pCC, mPFC, and temporo-parietal hubs in depressed individuals. Furthermore, high CRP was associated with significantly increased cortico-subcortical connectivity between three key hubs within the DMN: between the hippocampus and both the pC/pCC and mPFC (both of which also showed a positive dependency of PD on CRP), but lower connectivity of DMN (regions p10p, 7m and 31a) and other non-DMN areas to non-DMN sub-cortical regions (putamen and thalamus). Conclusions: Elevated CRP was associated with changes in both cortical micro-structure and subcortical connectivity within key nodes of the default mode network, a network critically implicated in the aetiology of depression, suggesting that effects of peripheral inflammation on pC/pCC and mPFC micro-structure may cause depressive symptoms by differentially modulating their cortico-subcortical connectivity to areas within and outside of the DMN.

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Default mode network anatomy and function is linked to pediatric concussion recovery

10.1101/795740 ◽

2019 ◽

Author(s):

Kartik K. Iyer ◽

Andrew Zalesky ◽

Karen M. Barlow ◽

Luca Cocchi

Keyword(s):

Functional Connectivity ◽

Sleep Disturbance ◽

Default Mode Network ◽

Grey Matter ◽

Post Injury ◽

Prognostic Information ◽

Functional Brain ◽

Default Mode ◽

Pediatric Concussion ◽

Concussion Recovery

ABSTRACTObjectiveTo determine whether anatomical and functional brain features relate to key persistent post-concussion symptoms (PPCS) in children recovering from mild traumatic brain injuries (mTBI), and whether such brain indices can predict individual recovery from PPCS.Methods110 children with mixed recovery following mTBI were seen at the concussion clinic at Neurology department Alberta Children’s Hospital. The primary outcome was the Post-Concussion Symptom Inventory (PCSI, parent proxy). Sleep disturbance scores (PCSI sub-domain) and the Neurocognition Index (CNS Vital Signs) were also measured longitudinally. PPCS was assessed at 4 weeks post-injury and 8-10 weeks post-injury. Grey matter volumes were assessed using magnetic resonance imaging (MRI) and voxel-based morphometry. Functional connectivity was estimated using resting-state MRI. Two complementary machine learning methods were used to assess if the combination of grey matter and functional connectivity indices carried meaningful prognostic information.ResultsHigher scores on a composite index of sleep disturbance, including fatigue, were associated with converging decreases in grey matter volume and local functional connectivity in two key nodes of the default mode network: the posterior cingulate cortex and the medial prefrontal cortex. Sleep-related disturbances also significantly correlated with reductions in functional connectivity between these brain regions. The combination of structural and functional brain indices associated to individual variations in the default mode network accurately predicted clinical outcomes at follow-up (area under the curve = 0.86).InterpretationThese results highlight that the function-structure profile of core default mode regions underpins sleep-related problems following mTBI and carries meaningful prognostic information for pediatric concussion recovery.

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Altered Resting-State Functional Connectivity in the Default Mode Network in Male Juvenile Violent Offenders

Brain Imaging and Behavior ◽

10.1007/s11682-021-00535-3 ◽

2021 ◽

Author(s):

Qiaoling Sun ◽

Yingdong Zhang ◽

Jiansong Zhou ◽

Xiaoping Wang

Keyword(s):

Functional Connectivity ◽

Default Mode Network ◽

Resting State ◽

Violent Offenders ◽

Magnetic Resonance Imaging Scan ◽

Negative Consequences ◽

Resting State Functional Connectivity ◽

Default Mode ◽

Juvenile Violence ◽

Normal Controls

AbstractYoung males are often associated with more violence, leading to some serious negative consequences. However, the physiology and the neuroimaging patterns underlying juvenile violence remain unclear. Of the limited knowledge on juvenile violence, the default mode network has been known to be associated with its pathophysiology. This study aimed to investigate functional connectivity alterations of the default mode network in male juvenile violent offenders. 31 juvenile violent offenders in a high-security facility, who were convicted of aggressive behaviors by court, and 28 normal controls from a middle school were recruited as participants. They underwent a resting-state functional magnetic resonance imaging scan. And independent component analysis approaches were used to analyze their data. Compared to the normal controls, the juvenile violent offenders showed a different default mode network pattern, with the functional connectivity increased in the posterior cingulate, and decreased in the right middle temporal, left angular, right precuneus and right middle frontal cortex. Our findings revealed that the male juvenile violent offenders were associated with abnormal default mode network functional connectivity, which might be a neuroimaging basis for their tendency to violence.

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