Disrupted intrinsic functional connectivity in the vegetative state

Cauda, Franco; Micon, B Massa; Sacco, Katiuscia; Duca, Sergio; D’Agata, Federico; Geminiani, Giuliano; Canavero, Sergio

doi:10.1136/jnnp.2007.142349

Cited by 124 publications

(87 citation statements)

References 18 publications

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“…In the current study, we used a comprehensive core-seed-based template for single-participant ICA to select the best fit of coactivation of DMN substructures. The template-based single-participant ICA is a novel automated approach in sorting independent components without subjective identification of the DMN (52,53). By using template-based ICA analysis, Greicius et al also showed improved specificity By using the hybrid ICA seed-based method, we found a similar but augmented pattern of increased frontal connectivity and decreased posterior connectivity of the DMN in patients compared with control subjects (Fig 4).…”

Section: Discussionsupporting

confidence: 59%

Default-Mode Network Disruption in Mild Traumatic Brain Injury

Zhou¹,

Milham²,

Lui³

et al. 2012

Radiology

260

236

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Purpose:To investigate the integrity of the default-mode network (DMN) by using independent component analysis (ICA) methods in patients shortly after mild traumatic brain injury (MTBI) and healthy control subjects, and to correlate DMN connectivity changes with neurocognitive tests and clinical symptoms. Materials and Methods:This study was approved by the institutional review board and complied with HIPAA regulations. Twenty-three patients with MTBI who had posttraumatic symptoms shortly after injury (,2 months) and 18 age-matched healthy control subjects were included in this study.Resting-state functional magnetic resonance imaging was performed at 3 T to characterize the DMN by using ICA methods, including a single-participant ICA on the basis of a comprehensive template from core seeds in the posterior cingulate cortex (PCC) and medial prefrontal cortex (MPFC) nodes. ICA z images of DMN components were compared between the two groups and correlated with neurocognitive tests and clinical performance in patients by using Pearson and Spearman rank correlation. Results:When compared with the control subjects, there was significantly reduced connectivity in the PCC and parietal regions and increased frontal connectivity around the MPFC in patients with MTBI (P , .01). These frontoposterior opposing changes within the DMN were significantly correlated (r = 20.44, P = .03). The reduced posterior connectivity correlated positively with neurocognitive dysfunction (eg, cognitive flexibility), while the increased frontal connectivity correlated negatively with posttraumatic symptoms (ie, depression, anxiety, fatigue, and postconcussion syndrome). Conclusion:These results showed abnormal DMN connectivity patterns in patients with MTBI, which may provide insight into how neuronal communication and information integration are disrupted among DMN key structures after mild head injury. Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. (25) showed decreased connectivity within DMN nodes and increased headache, dizziness, fatigue, irritability, insomnia, poor concentration, memory difficulty, or an intolerance of stress, emotion, or alcohol) that have lasted at least 3 months (6), as well as evidence of deficits in attention and memory (7). PCS is frequently overlooked at the time of initial injury and can develop and persist for variable periods of time. However, the underlying pathophysiology of PCS is still poorly understood.In recent years, resting-state functional magnetic resonance (MR) imaging has enabled evaluation of critical brain networks on the basis of baseline energy expenditure in awake and resting states of the brain. Resting-state networks are composed of brain regions with highly correlated time courses of robust low-frequency (,0.1 Hz) blood oxygen level-dependent signal fluctuations (8), which are believed to represent the maintenance of baseline human cognition and metab...

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Section: Discussionsupporting

confidence: 59%

Default-Mode Network Disruption in Mild Traumatic Brain Injury

Zhou¹,

Milham²,

Lui³

et al. 2012

Radiology

260

236

View full text Add to dashboard Cite

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“…Resting-state networks have been defined as patterns of correlated bloodoxygen level-dependent signal in a task-free state; these correlations of activity are thought to represent underlying functional connectivity. 14 Most of these studies have focused on resting-state network changes in patients with chronic disorders of consciousness (particularly the vegetative state or unresponsive wakefulness syndrome) and have demonstrated alterations in connectivity of the default mode network (DMN) [15][16][17] by comparison with control subjects. The DMN is a functionally connected set of brain regions, including the posterior cingulate/precuneus (PCC), medial prefrontal cortex, and lateral parietal lobe that is known to exhibit taskrelated deactivation 18,19 and may be responsible for phenomena including mind wandering during the task-free state.…”

Section: Strokementioning

confidence: 99%

Frontal Networks Associated With Command Following After Hemorrhagic Stroke

Mikell

Banks

Frey

et al. 2015

Stroke

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Background and Purpose-Level of consciousness is frequently assessed by command-following ability in the clinical setting. However, it is unclear what brain circuits are needed to follow commands. We sought to determine what networks differentiate command following from noncommand following patients after hemorrhagic stroke. Methods-Structural MRI, resting-state functional MRI, and electroencephalography were performed on 25 awake and unresponsive patients with acute intracerebral and subarachnoid hemorrhage. Structural injury was assessed via volumetric T1-weighted MRI analysis. Functional connectivity differences were analyzed against a template of standard resting-state networks. The default mode network (DMN) and the task-positive network were investigated using seedbased functional connectivity. Networks were interrogated by pairwise coherence of electroencephalograph leads in regions of interest defined by functional MRI. Results-Functional imaging of unresponsive patients identified significant differences in 6 of 16 standard resting-state networks. Significant voxels were found in premotor cortex, dorsal anterior cingulate gyrus, and supplementary motor area. Direct interrogation of the DMN and task-positive network revealed loss of connectivity between the DMN and the orbitofrontal cortex and new connections between the task-positive network and DMN. Coherence between electrodes corresponding to right executive network and visual networks was also decreased in unresponsive patients. Conclusions-Resting

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“…71,93,94 The best-studied network is the default mode network (DMN) encompassing the posterior and anterior cortical midline structures, which are considered to be involved in stimulus-independent thought, mind-wandering and self-consciousness. 95 The DMN was shown to be absent in brain death, 96 but still partially preserved in VS, [97][98][99] probably reflecting residual structural connectivity. 93 At the group level, resting-state network activity revealed reduced interhemispheric connectivity 100 and correlated with levels of consciousness in patients with DOC ( Figure 2).…”

Section: Functional Mrimentioning

confidence: 99%

Disorders of consciousness after acquired brain injury: the state of the science

et al. 2014

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| The concept of consciousness continues to defy definition and elude the grasp of philosophical and scientific efforts to formulate a testable construct that maps to human experience. Severe acquired brain injury results in the dissolution of consciousness, providing a natural model from which key insights about consciousness may be drawn. In the clinical setting, neurologists and neurorehabilitation specialists are called on to discern the level of consciousness in patients who are unable to communicate through word or gesture, and to project outcomes and recommend approaches to treatment. Standards of care are not available to guide clinical decision-making for this population, often leading to inconsistent, inaccurate and inappropriate care. In this Review, we describe the state of the science with regard to clinical management of patients with prolonged disorders of consciousness. We review consciousness-altering pathophysiological mechanisms, specific clinical syndromes, and novel diagnostic and prognostic applications of advanced neuroimaging and electrophysiological procedures. We conclude with a provocative discussion of bioethical and medicolegal issues that are unique to this population and have a profound impact on care, as well as raising questions of broad societal interest.

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Disrupted intrinsic functional connectivity in the vegetative state

Cited by 124 publications

References 18 publications

Default-Mode Network Disruption in Mild Traumatic Brain Injury

Default-Mode Network Disruption in Mild Traumatic Brain Injury

Frontal Networks Associated With Command Following After Hemorrhagic Stroke

Disorders of consciousness after acquired brain injury: the state of the science

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