scholarly journals Functional Networks in Disorders of Consciousness

2017 ◽  
Vol 37 (05) ◽  
pp. 485-502 ◽  
Author(s):  
Camille Chatelle ◽  
Brian Edlow ◽  
Yelena Bodien
Keyword(s):  
Effective Connectivity ◽  
Clinical Care ◽  
Network Connectivity ◽  
Disorders Of Consciousness ◽  
Functional Network ◽  
Functional Networks ◽  
Positron Emission ◽  
Essential Components ◽  
Network Mapping

AbstractSevere brain injury may cause disruption of neural networks that sustain arousal and awareness, the two essential components of consciousness. Despite the potentially devastating immediate and long-term consequences, disorders of consciousness (DoC) are poorly understood in terms of their underlying neurobiology, the relationship between pathophysiology and recovery, and the predictors of treatment efficacy. Recent advances in neuroimaging techniques have enabled the study of network connectivity, providing great potential to improve the clinical care of patients with DoC. Initial discoveries in this field were made using positron emission tomography (PET). More recently, functional magnetic resonance (fMRI) techniques have added to our understanding of functional network dynamics in this population. Both methods have shown that whether at rest or performing a goal-oriented task, functional networks essential for processing intrinsic thoughts and extrinsic stimuli are disrupted in patients with DoC compared with healthy subjects. Atypical connectivity has been well established in the default mode network as well as in other cortical and subcortical networks that may be required for consciousness. Moreover, the degree of altered connectivity may be related to the severity of impaired consciousness, and recovery of consciousness has been shown to be associated with restoration of connectivity. In this review, we discuss PET and fMRI studies of functional and effective connectivity in patients with DoC and suggest how this field can move toward clinical application of functional network mapping in the future.

scholarly journals Alzheimer’s Disease Progressively Reduces Visual Functional Network Connectivity

2021 ◽  
pp. 1-14
Author(s):  
Jie Huang ◽  
Paul Beach ◽  
Andrea Bozoki ◽  
David C. Zhu
Keyword(s):  
Visual Cortex ◽  
Lower Order ◽  
Resting State ◽  
Visual Processing ◽  
Network Connectivity ◽  
Higher Order ◽  
Functional Network ◽  
Functional Networks ◽  
The Face ◽  
Processing Network

Background: Postmortem studies of brains with Alzheimer’s disease (AD) not only find amyloid-beta (Aβ) and neurofibrillary tangles (NFT) in the visual cortex, but also reveal temporally sequential changes in AD pathology from higher-order association areas to lower-order areas and then primary visual area (V1) with disease progression. Objective: This study investigated the effect of AD severity on visual functional network. Methods: Eight severe AD (SAD) patients, 11 mild/moderate AD (MAD), and 26 healthy senior (HS) controls undertook a resting-state fMRI (rs-fMRI) and a task fMRI of viewing face photos. A resting-state visual functional connectivity (FC) network and a face-evoked visual-processing network were identified for each group. Results: For the HS, the identified group-mean face-evoked visual-processing network in the ventral pathway started from V1 and ended within the fusiform gyrus. In contrast, the resting-state visual FC network was mainly confined within the visual cortex. AD disrupted these two functional networks in a similar severity dependent manner: the more severe the cognitive impairment, the greater reduction in network connectivity. For the face-evoked visual-processing network, MAD disrupted and reduced activation mainly in the higher-order visual association areas, with SAD further disrupting and reducing activation in the lower-order areas. Conclusion: These findings provide a functional corollary to the canonical view of the temporally sequential advancement of AD pathology through visual cortical areas. The association of the disruption of functional networks, especially the face-evoked visual-processing network, with AD severity suggests a potential predictor or biomarker of AD progression.

scholarly journals Neuroimaging for Disorders of Consciousness: Ethical Priorities in Research, Policy, and Translation

2015 ◽  
Vol 42 (S1) ◽  
pp. S18-S18
Author(s):  
AC Byram ◽  
G Lee ◽  
AM Owen ◽  
U Ribrary ◽  
J Stoessl ◽  
...  
Keyword(s):  
Health Care Professionals ◽  
Research Policy ◽  
Clinical Care ◽  
Health Resources ◽  
Disorders Of Consciousness ◽  
Term Care ◽  
Legal Competence ◽  
Neuroimaging Techniques ◽  
Research And Policy

Background: Acquired brain injury is a critical health problem in Canada, placing greater demands on health resources as improvements in intensive care lead to more patients in long-term care. Clinical diagnosis of patients with disorders of consciousness remains difficult, but advances in neuroimaging research have the potential to reshape clinical management of such patients or provide unprecedented ways to communicate with them. Building on our earlier work, this study identifies ethically salient priorities for research and policy before translation of this promising technology. Methods: We interviewed 27 Canadian researchers, ethicists, lawyers, practitioners, allied health care professionals, and patient advocacy leaders, with expertise in neuroimaging or disorders of consciousness. Interviews were semi-structured and data were analyzed for emergent themes. Results: Participants were optimistic that neuroimaging could lead to improved clinical care. They discussed mitigating the risks of misinterpreting results and communication, creating guidelines for clinical use, and defining legal competence in this neuroimaging context as key ethical priorities for translation. Conclusions: The transition of neuroimaging techniques for disorders of consciousness from research to clinical care may yield substantial benefits to these patients, but first requires resolution of research, policy, and translational issues.

scholarly journals Seizure Diaries and Forecasting With Wearables: Epilepsy Monitoring Outside the Clinic

2021 ◽  
Vol 12 ◽  
Author(s):  
Benjamin H. Brinkmann ◽  
Philippa J. Karoly ◽  
Ewan S. Nurse ◽  
Sonya B. Dumanis ◽  
Mona Nasseri ◽  
...  
Keyword(s):  
Electrodermal Activity ◽  
Clinical Care ◽  
Wearable Devices ◽  
Current Evidence ◽  
Computer Assisted ◽  
Non Invasive ◽  
Probabilistic Forecasts ◽  
Essential Components ◽  
Epilepsy Monitoring

It is a major challenge in clinical epilepsy to diagnose and treat a disease characterized by infrequent seizures based on patient or caregiver reports and limited duration clinical testing. The poor reliability of self-reported seizure diaries for many people with epilepsy is well-established, but these records remain necessary in clinical care and therapeutic studies. A number of wearable devices have emerged, which may be capable of detecting seizures, recording seizure data, and alerting caregivers. Developments in non-invasive wearable sensors to measure accelerometry, photoplethysmography (PPG), electrodermal activity (EDA), electromyography (EMG), and other signals outside of the traditional clinical environment may be able to identify seizure-related changes. Non-invasive scalp electroencephalography (EEG) and minimally invasive subscalp EEG may allow direct measurement of seizure activity. However, significant network and computational infrastructure is needed for continuous, secure transmission of data. The large volume of data acquired by these devices necessitates computer-assisted review and detection to reduce the burden on human reviewers. Furthermore, user acceptability of such devices must be a paramount consideration to ensure adherence with long-term device use. Such devices can identify tonic–clonic seizures, but identification of other seizure semiologies with non-EEG wearables is an ongoing challenge. Identification of electrographic seizures with subscalp EEG systems has recently been demonstrated over long (>6 month) durations, and this shows promise for accurate, objective seizure records. While the ability to detect and forecast seizures from ambulatory intracranial EEG is established, invasive devices may not be acceptable for many individuals with epilepsy. Recent studies show promising results for probabilistic forecasts of seizure risk from long-term wearable devices and electronic diaries of self-reported seizures. There may also be predictive value in individuals' symptoms, mood, and cognitive performance. However, seizure forecasting requires perpetual use of a device for monitoring, increasing the importance of the system's acceptability to users. Furthermore, long-term studies with concurrent EEG confirmation are lacking currently. This review describes the current evidence and challenges in the use of minimally and non-invasive devices for long-term epilepsy monitoring, the essential components in remote monitoring systems, and explores the feasibility to detect and forecast impending seizures via long-term use of these systems.

scholarly journals Correlation between the oral microbiome and brain resting state connectivity in smokers

2018 ◽  
Author(s):  
Dongdong Lin ◽  
Kent E. Hutchison ◽  
Salvador Portillo ◽  
Victor Vegara ◽  
Jarrod M. Ellingson ◽  
...  
Keyword(s):  
Microbial Community ◽  
Network Connectivity ◽  
Oral Microbiome ◽  
Functional Network ◽  
Functional Networks ◽  
Functional Network Connectivity ◽  
Brain Functional Network ◽  
Brain Functional Networks ◽  
The Brain

AbstractRecent studies have shown a critical role of the gastrointestinal microbiome in brain and behavior via the complex gut–microbiome–brain axis, however, the influence of the oral microbiome in neurological processes is much less studied, especially in response to the stimuli in the oral microenvironment such as smoking. Additionally, given the complex structural and functional networks in brain system, our knowledge about the relationship between microbiome and brain function in specific brain circuits is still very limited. In this pilot work, we leveraged next generation microbial sequencing with functional neuroimaging techniques to enable the delineation of microbiome-brain network links as well as their relationship to cigarette smoking. Thirty smokers and 30 age- and sex- matched non-smokers were recruited for measuring both microbial community and brain functional networks. Statistical analyses were performed to demonstrate the influence of smoking on the abundance of the constituents within the oral microbial community and functional network connectivity among brain regions as well as the associations between microbial shifts and the brain functional network connectivity alternations. Compared to non-smokers, we found a significant decrease in beta diversity (p = 6×10−3) in smokers and identified several classes (Betaproteobacteria, Spirochaetia, Synergistia, and Mollicutes) as having significant alterations in microbial abundance. Taxonomic analyses demonstrate that the microbiota with altered abundance are mainly involved in pathways related to cell processes, DNA repair, immune system, and neurotransmitters signaling. One brain functional network connectivity component was identified to have a significant difference between smokers and nonsmokers (p = 0.033), mainly including connectivity between brain default network and other task-positive networks. The brain functional component was also significantly associated with some smoking related oral microbiota, suggesting a potential link between smoking-induced oral microbiome dysbiosis and brain functional connectivity, possibly through immunological and neurotransmitter signaling pathways. This work is the first attempt to link oral microbiome and brain functional networks, and provides support for future work in characterizing the role of oral microbiome in mediating smoking effects on brain activity.

scholarly journals The importance of maternal pregnancy vitamin D for offspring bone health: learnings from the MAVIDOS trial

2021 ◽  
Vol 13 ◽  
pp. 1759720X2110069
Author(s):  
Rebecca J. Moon ◽  
Elizabeth M. Curtis ◽  
Stephen J. Woolford ◽  
Shanze Ashai ◽  
Cyrus Cooper ◽  
...  
Keyword(s):  
Vitamin D ◽  
Bone Development ◽  
Controlled Trial ◽  
Clinical Care ◽  
Later Life ◽  
Vitamin D Supplementation ◽  
Public Health Policies ◽  
Positive Effects

Optimisation of skeletal mineralisation in childhood is important to reduce childhood fracture and the long-term risk of osteoporosis and fracture in later life. One approach to achieving this is antenatal vitamin D supplementation. The Maternal Vitamin D Osteoporosis Study is a randomised placebo-controlled trial, the aim of which was to assess the effect of antenatal vitamin D supplementation (1000 IU/day cholecalciferol) on offspring bone mass at birth. The study has since extended the follow up into childhood and diversified to assess demographic, lifestyle and genetic factors that determine the biochemical response to antenatal vitamin D supplementation, and to understand the mechanisms underpinning the effects of vitamin D supplementation on offspring bone development, including epigenetics. The demonstration of positive effects of maternal pregnancy vitamin D supplementation on offspring bone development and the delineation of underlying biological mechanisms inform clinical care and future public-health policies.

scholarly journals Disrupted metabolic connectivity in dopaminergic and cholinergic networks at different stages of dementia from 18F-FDG PET brain persistent homology network

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tun-Wei Hsu ◽  
Jong-Ling Fuh ◽  
Da-Wei Wang ◽  
Li-Fen Chen ◽  
Chia-Jung Chang ◽  
...  
Keyword(s):  
Algebraic Topology ◽  
Fdg Pet ◽  
Persistent Homology ◽  
Network Connectivity ◽  
Brain Regions ◽  
Imaging Data ◽  
Cholinergic Pathways ◽  
Positron Emission ◽  
Metabolic Connectivity ◽  
Neurochemical Changes

AbstractDementia is related to the cellular accumulation of β-amyloid plaques, tau aggregates, or α-synuclein aggregates, or to neurotransmitter deficiencies in the dopaminergic and cholinergic pathways. Cellular and neurochemical changes are both involved in dementia pathology. However, the role of dopaminergic and cholinergic networks in metabolic connectivity at different stages of dementia remains unclear. The altered network organisation of the human brain characteristic of many neuropsychiatric and neurodegenerative disorders can be detected using persistent homology network (PHN) analysis and algebraic topology. We used 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging data to construct dopaminergic and cholinergic metabolism networks, and used PHN analysis to track the evolution of these networks in patients with different stages of dementia. The sums of the network distances revealed significant differences between the network connectivity evident in the Alzheimer’s disease and mild cognitive impairment cohorts. A larger distance between brain regions can indicate poorer efficiency in the integration of information. PHN analysis revealed the structural properties of and changes in the dopaminergic and cholinergic metabolism networks in patients with different stages of dementia at a range of thresholds. This method was thus able to identify dysregulation of dopaminergic and cholinergic networks in the pathology of dementia.

scholarly journals Proceedings of the First Curing Coma Campaign NIH Symposium: Challenging the Future of Research for Coma and Disorders of Consciousness

2021 ◽  
Vol 35 (S1) ◽  
pp. 4-23
Author(s):  
Jan Claassen ◽  
Yama Akbari ◽  
Sheila Alexander ◽  
Mary Kay Bader ◽  
Kathleen Bell ◽  
...  
Keyword(s):  
Neurocritical Care ◽  
Panel Discussion ◽  
Large Datasets ◽  
Disorders Of Consciousness ◽  
National Institutes Of Health ◽  
Proof Of Concept ◽  
Research Gaps ◽  
Main Research ◽  
The World

AbstractComa and disorders of consciousness (DoC) are highly prevalent and constitute a burden for patients, families, and society worldwide. As part of the Curing Coma Campaign, the Neurocritical Care Society partnered with the National Institutes of Health to organize a symposium bringing together experts from all over the world to develop research targets for DoC. The conference was structured along six domains: (1) defining endotype/phenotypes, (2) biomarkers, (3) proof-of-concept clinical trials, (4) neuroprognostication, (5) long-term recovery, and (6) large datasets. This proceedings paper presents actionable research targets based on the presentations and discussions that occurred at the conference. We summarize the background, main research gaps, overall goals, the panel discussion of the approach, limitations and challenges, and deliverables that were identified.

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