scholarly journals NIMG-69. PERSONALIZED CONNECTOMIC SIGNATURES: BRIDGING THE GAP BETWEEN NEURO-ONCOLOGY AND CONNECTOMICS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii163-ii163
Author(s):  
Yusuf Osmanlioglu ◽  
Drew Parker ◽  
Steven Brem ◽  
Ali Shokoufandeh ◽  
Ragini Verma
Keyword(s):  
Graph Matching ◽  
Structural Connectivity ◽  
Specific Treatment ◽  
Mass Effect ◽  
Geometrical Shape ◽  
Registration Method ◽  
Tumor Patient ◽  
Atlas Registration ◽  
Healthy Control ◽  
The Brain

Abstract PURPOSE Connectomics has led to significant neuroscientific findings within the last two decades, eventually making impact in the clinics. Neuro-oncology can benefit immensely from connectomics in evaluating structural connectivity of brains with tumor for pre- and post-treatment planning, as a tumor connectome along with derived network measures will make it possible to determine the cognitive effects of treatment and quantify the effect of surgery on quality of life. However, generating connectomes in the presence of tumor is a challenging task. Specifically, registration of an atlas to the brain, which is essential in parcellating the brain into regions of interest, fails around the tumor due to mass effect and infiltration related distortions which are not present in the atlas that comes from a healthy brain. We aim to tackle this problem by introducing a novel atlas registration method. METHOD Although tumor deforms the geometrical shape of its surrounding regions, it does not violate the connectivity of displaced cortical voxels to the rest of the brain. Leveraging this fact, we represent the brain as an annotated graph with nodes representing ROIs encoding geometric features of regions and weighted edges representing the connectivity between regions. In encoding the surroundings of the tumor into the graph, we subsample the region into smaller patches to represent the area with multiple nodes. We then calculate many-to-one graph matching between the graphs of a tumor patient and a healthy control to associate surroundings of tumor with healthy ROIs. OUTCOME A tumor connectome showing how the connectivity is morphed around the tumor, which can further be extended to creating connectomes of recurrence. CLINICAL IMPLICATIONS Use of connectomes can revolutionize neuro-oncology by helping surgeons in estimating structural, functional, and behavioral outcomes of resection prior to surgery and in predicting recovery after the surgery, potentially suggesting subject specific treatment plans.

scholarly journals Quantifying structural connectivity in brain tumor patients

2021 ◽  
Author(s):  
Yiran Wei ◽  
Chao Li ◽  
Stephen John Price
Keyword(s):  
Brain Tumor ◽  
White Matter ◽  
Robust Estimation ◽  
Brain Connectivity ◽  
Structural Connectivity ◽  
Mass Effect ◽  
Brain Regions ◽  
Brain Network ◽  
Tumor Patients ◽  
The Brain

AbstractBrain tumors are characterised by infiltration along the white matter tracts, posing significant challenges to precise treatment. Mounting evidence shows that an infiltrating tumor can interfere with the brain network diffusely. Therefore, quantifying structural connectivity has potential to identify tumor invasion and stratify patients more accurately. The tract-based statistics (TBSS) is widely used to measure the white matter integrity. This voxel-wise method, however, cannot directly quantify the connectivity of brain regions. Tractography is a fiber tracking approach, which has been widely used to quantify brain connectivity. However, the performance of tractography on the brain with tumors is complicated by the tumor mass effect. A robust method of quantifying the structural connectivity strength in brain tumor patients is still lacking.Here we propose a method which could provide robust estimation of tract strength for brain tumor patients. Specifically, we firstly construct an unbiased tract template in healthy subjects using tractography. The voxel projection of TBSS is employed to quantify the tract connectivity in patients, using the location of each tract fiber from the template. To further improve the standard TBSS, we propose an approach of iterative projection of tract voxels guided by the tract orientation measured using the voxel-wise eigenvectors. Compared to state-of-the-art tractography, our approach is more sensitive in reflecting more functional relevance. Further, the different extent of network disruption revealed by our approach correspond to the clinical prior knowledge of tumor histology. The proposed method could provide a robust estimation of the structural connectivity for brain tumor patients.

scholarly journals An architectonic type principle in the development of laminar patterns of cortico-cortical connections

2021 ◽  
Author(s):  
Sarah F. Beul ◽  
Alexandros Goulas ◽  
Claus C. Hilgetag
Keyword(s):  
Structural Connectivity ◽  
Macaque Monkey ◽  
Brain Regions ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Cortical Connections ◽  
Cortical Projections ◽  
Structural Connections ◽  
High Degree ◽  
The Brain

AbstractStructural connections between cortical areas form an intricate network with a high degree of specificity. Many aspects of this complex network organization in the adult mammalian cortex are captured by an architectonic type principle, which relates structural connections to the architectonic differentiation of brain regions. In particular, the laminar patterns of projection origins are a prominent feature of structural connections that varies in a graded manner with the relative architectonic differentiation of connected areas in the adult brain. Here we show that the architectonic type principle is already apparent for the laminar origins of cortico-cortical projections in the immature cortex of the macaque monkey. We find that prenatal and neonatal laminar patterns correlate with cortical architectonic differentiation, and that the relation of laminar patterns to architectonic differences between connected areas is not substantially altered by the complete loss of visual input. Moreover, we find that the degree of change in laminar patterns that projections undergo during development varies in proportion to the relative architectonic differentiation of the connected areas. Hence, it appears that initial biases in laminar projection patterns become progressively strengthened by later developmental processes. These findings suggest that early neurogenetic processes during the formation of the brain are sufficient to establish the characteristic laminar projection patterns. This conclusion is in line with previously suggested mechanistic explanations underlying the emergence of the architectonic type principle and provides further constraints for exploring the fundamental factors that shape structural connectivity in the mammalian brain.

scholarly journals Harmonic Brain Modes: A Unifying Framework for Linking Space and Time in Brain Dynamics

2017 ◽  
Vol 24 (3) ◽  
pp. 277-293 ◽  
Author(s):  
Selen Atasoy ◽  
Gustavo Deco ◽  
Morten L. Kringelbach ◽  
Joel Pearson
Keyword(s):  
Neural Activity ◽  
Brain Activity ◽  
Activity Patterns ◽  
Structural Connectivity ◽  
Building Blocks ◽  
Mental States ◽  
Brain Dynamics ◽  
Space And Time ◽  
Wide Range ◽  
The Brain

A fundamental characteristic of spontaneous brain activity is coherent oscillations covering a wide range of frequencies. Interestingly, these temporal oscillations are highly correlated among spatially distributed cortical areas forming structured correlation patterns known as the resting state networks, although the brain is never truly at “rest.” Here, we introduce the concept of harmonic brain modes—fundamental building blocks of complex spatiotemporal patterns of neural activity. We define these elementary harmonic brain modes as harmonic modes of structural connectivity; that is, connectome harmonics, yielding fully synchronous neural activity patterns with different frequency oscillations emerging on and constrained by the particular structure of the brain. Hence, this particular definition implicitly links the hitherto poorly understood dimensions of space and time in brain dynamics and its underlying anatomy. Further we show how harmonic brain modes can explain the relationship between neurophysiological, temporal, and network-level changes in the brain across different mental states ( wakefulness, sleep, anesthesia, psychedelic). Notably, when decoded as activation of connectome harmonics, spatial and temporal characteristics of neural activity naturally emerge from the interplay between excitation and inhibition and this critical relation fits the spatial, temporal, and neurophysiological changes associated with different mental states. Thus, the introduced framework of harmonic brain modes not only establishes a relation between the spatial structure of correlation patterns and temporal oscillations (linking space and time in brain dynamics), but also enables a new dimension of tools for understanding fundamental principles underlying brain dynamics in different states of consciousness.

Occlusive arteriopathy and brain tumor

1978 ◽  
Vol 49 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Koreaki Mori ◽  
Fuji Takeuchi ◽  
Masatsune Ishikawa ◽  
Hajime Handa ◽  
Mitsuo Toyama ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Cerebral Angiography ◽  
Mass Effect ◽  
Clinical Analysis ◽  
Sudden Onset ◽  
Circle Of Willis ◽  
Ischemic Lesion ◽  
Neurocutaneous Syndrome ◽  
The Brain ◽  
Occlusive Arteriopathy

✓ Four cases with the association of occlusive arteriopathy and brain tumor are presented. A clinical analysis of these cases and cases reported in the literature revealed that occlusive arteriopathy at the base of the brain was often associated with a slowly growing basal tumor in children. Possible causes of occlusive arteriopathy in these cases were compression of the circle of Willis by a slowly growing basal tumor, secondary arterial occlusive changes by radiation therapy for a basal tumor, or vasculopathy associated with neurocutaneous syndrome. Symptoms of sudden onset or episodic nature suggest the presence of occlusive arteriopathy rather than the mass effect of a tumor. Cerebral angiography is mandatory whenever computerized tomography (CT), performed to rule out recurrence of a basal tumor, shows an ischemic lesion with low-density areas without any evidence of mass effect of the tumor. Cerebral angiography is also necessary when a basal tumor is suspected in children, particularly in cases associated with neurocutaneous syndrome and a basal tumor. Care should be taken not to scarify the abnormal vascular network at the base of the brain at the time of operation, because it is considered to be functioning as collateral circulation. The potential hazards of radiotherapy to radiation-induced occlusive changes of the circle of Willis must be considered in treating a benign basal brain tumor in children. Even in adults, repeated large doses of irradiation could cause occlusive arteriopathy.

scholarly journals Distinct structure-function relationships across cortical regions and connectivity scales in the rat brain

2019 ◽  
Author(s):  
Milou Straathof ◽  
Michel R.T. Sinke ◽  
Theresia J.M. Roelofs ◽  
Erwin L.A. Blezer ◽  
R. Angela Sarabdjitsingh ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Structure Function ◽  
Rat Brain ◽  
Resting State ◽  
Structural Connectivity ◽  
Distinct Structure ◽  
Macro Scale ◽  
Function Relationship ◽  
The Brain ◽  
Meso Scale

AbstractAn improved understanding of the structure-function relationship in the brain is necessary to know to what degree structural connectivity underpins abnormal functional connectivity seen in many disorders. We integrated high-field resting-state fMRI-based functional connectivity with high-resolution macro-scale diffusion-based and meso-scale neuronal tracer-based structural connectivity, to obtain an accurate depiction of the structure-function relationship in the rat brain. Our main goal was to identify to what extent structural and functional connectivity strengths are correlated, macro- and meso-scopically, across the cortex. Correlation analyses revealed a positive correspondence between functional connectivity and macro-scale diffusion-based structural connectivity, but no correspondence between functional connectivity and meso-scale neuronal tracer-based structural connectivity. Locally, strong functional connectivity was found in two well-known resting-state networks: the sensorimotor and default mode network. Strong functional connectivity within these networks coincided with strong short-range intrahemispheric structural connectivity, but with weak heterotopic interhemispheric and long-range intrahemispheric structural connectivity. Our study indicates the importance of combining measures of connectivity at distinct hierarchical levels to accurately determine connectivity across networks in the healthy and diseased brain. Distinct structure-function relationships across the brain can explain the organization of networks and may underlie variations in the impact of structural damage on functional networks and behavior.

scholarly journals Compositional Restricted Boltzmann Machines Unveil the Brain-Wide Organization of Neural Assemblies

2021 ◽  
Author(s):  
Thijs L van der Plas ◽  
Jérôme Tubiana ◽  
Guillaume Le Goc ◽  
Geoffrey Migault ◽  
Michael Kunst ◽  
...  
Keyword(s):  
Structural Connectivity ◽  
Connectivity Matrix ◽  
Restricted Boltzmann Machines ◽  
Pairwise Correlation ◽  
Neural Assemblies ◽  
Data Statistics ◽  
Endogenous Activity ◽  
Brain Data ◽  
Correlation Statistics ◽  
The Brain

Patterns of endogenous activity in the brain reflect a stochastic exploration of the neuronal state space that is constrained by the underlying assembly organization of neurons. Yet it remains to be shown that this interplay between neurons and their assembly dynamics indeed suffices to generate whole-brain data statistics. Here we recorded the activity from ~40,000 neurons simultaneously in zebrafish larvae, and show that a data-driven network model of neuron-assembly interactions can accurately reproduce the mean activity and pairwise correlation statistics of their spontaneous activity. This model, the compositional Restricted Boltzmann Machine, unveils ~200 neural assemblies, which compose neurophysiological circuits and whose various combinations form successive brain states. From this, we mathematically derived an interregional functional connectivity matrix, which is conserved across individual animals and correlates well with structural connectivity. This novel, assembly-based generative model of brain-wide neural dynamics enables physiology-bound perturbation experiments in silico.

scholarly journals Local and Distant responses to single pulse electrical stimulation reflect different forms of connectivity

2020 ◽  
Author(s):  
Britni Crocker ◽  
Lauren Ostrowski ◽  
Ziv M. Williams ◽  
Darin D. Dougherty ◽  
Emad N. Eskandar ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Resting State ◽  
Diffusion Tensor ◽  
Effective Connectivity ◽  
Clinical Care ◽  
Structural Connectivity ◽  
Intractable Epilepsy ◽  
Single Pulse ◽  
Intracranial Electrode ◽  
The Brain

AbstractBackgroundMeasuring connectivity in the human brain can involve innumerable approaches using both noninvasive (fMRI, EEG) and invasive (intracranial EEG or iEEG) recording modalities, including the use of external probing stimuli, such as direct electrical stimulation.Objective/HypothesisTo examine how different measures of connectivity correlate with one another, we compared ‘passive’ measures of connectivity during resting state conditions map to the more ‘active’ probing measures of connectivity with single pulse electrical stimulation (SPES).MethodsWe measured the network engagement and spread of the cortico-cortico evoked potential (CCEP) induced by SPES at 53 total sites across the brain, including cortical and subcortical regions, in patients with intractable epilepsy (N=11) who were undergoing intracranial recordings as a part of their clinical care for identifying seizure onset zones. We compared the CCEP network to functional, effective, and structural measures of connectivity during a resting state in each patient. Functional and effective connectivity measures included correlation or Granger causality measures applied to stereoEEG (sEEGs) recordings. Structural connectivity was derived from diffusion tensor imaging (DTI) acquired before intracranial electrode implant and monitoring (N=8).ResultsThe CCEP network was most similar to the resting state voltage correlation network in channels near to the stimulation location. In contrast, the distant CCEP network was most similar to the DTI network. Other connectivity measures were not as similar to the CCEP network.ConclusionsThese results demonstrate that different connectivity measures, including those derived from active stimulation-based probing, measure different, complementary aspects of regional interrelationships in the brain.

scholarly journals Identification and Research of Adhd and Healthy Controls using Fmri

2019 ◽  
Vol 8 (6S) ◽  
pp. 370-372
Keyword(s):  
Brain Regions ◽  
Healthy Controls ◽  
Hyperactivity Disorder ◽  
Network Activation ◽  
Healthy Control ◽  
Temporal And Spatial ◽  
The Individual ◽  
The Brain ◽  
Coronal View

Analyzing the brain regions for different activations corresponding to the activation input for an experimental setup of task functional MRI or a resting state functional Magnetic Resonance Imaging(fMRI) for a diagnosed or healthy control is a challenging issue as the processing data is voluminous 4D data with nearly 1,51,552 voxels for a single volume of 261 scans fMRI. The data considered for analysis consists of 10 healthy controls and 10 Attention Deficit Hyperactivity Disorder(ADHD) fMRI. The workflow starts with preprocessing the individual scan for realignment, coregistration and Normalisation to Montreal Neurological Institute (MNI) space. Single site scan visit consists of 64x64x37 voxels. Seventy independent components are obtained from processed data by data reduction, Independent Component Analysis (ICA) calculation, Back reconstruction and Component Calibration. ICA performs satisfactorily well on temporal and spatial localization. Visual medial network activation is pronounced in ADHD Controls than in healthy people. Sagittal, Axial and Coronal view of ADHD controls is obtained as component number 42.The analysis is further used for the automatic classification of healthy controls and ADHD people.

Spontaneous resolution of invasive cerebral aspergillosis following partial resection in a medically untreated infant

2012 ◽  
Vol 10 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Sumit Thakar ◽  
Yasha T. Chickabasaviah ◽  
Alangar S. Hegde
Keyword(s):  
Emergency Services ◽  
Mass Effect ◽  
Cerebral Hemiatrophy ◽  
Right Cerebral Hemisphere ◽  
History Of ◽  
Subcortical Regions ◽  
The Right ◽  
Mri Study ◽  
The Brain

Invasive craniocerebral aspergillosis, often encountered in an immunocompromised setting, is almost uniformly fatal despite radical surgical and medical management, and is frequently a necropsy finding. The authors report a unique, self-resolving clinical course of this aggressive infection in a 10-month-old infant. The infant was brought to the emergency services in altered sensorium with a 1-week history of left-sided hemiparesis, excessive irritability, and vomiting. An MRI study of the brain revealed multiple, heterogeneously enhancing lesions in the right cerebral hemisphere with mass effect. The largest lesion in the frontotemporal cortical and subcortical regions was decompressed on an emergent basis. Histopathological findings were suggestive of invasive aspergillosis, although there was no evidence of the infection in the lungs or paranasal sinuses. Computed tomography–guided aspiration of the remaining lesions and follow-up antifungal therapy were recommended. The parents, however, requested discharge without further treatment. The child was seen at a follow-up visit 3 years later without having received any antifungal treatment. Imaging showed resolution of the infection and features of Dyke-Davidoff-Masson syndrome (cerebral hemiatrophy). This report of invasive cerebral aspergillosis resolving without medical therapy is the first of its kind. Its clinicoradiological aspects are discussed in light of previously reported cases.

Clinical case of semilobar holoprosencephaly

2021 ◽  
Author(s):  
А.В. Серёжкина ◽  
И.Г. Хмелевская ◽  
Н.С. Разинькова ◽  
Т.А. Миненкова ◽  
И.И. Жизневская ◽  
...  
Keyword(s):  
Clinical Case ◽  
Fatal Outcome ◽  
Clinical Manifestations ◽  
Specific Treatment ◽  
Stable Condition ◽  
Horseshoe Kidney ◽  
Structural Defects ◽  
Surgical Interventions ◽  
Ultrasound Diagnostics ◽  
The Brain

Поскольку непосредственные этиологические факторы аномалии развития не известны, в работе выделены основные группы причин, способствующих формированию пороков развития головного мозга. Большое значение отводится ранней диагностике пороков развития, которая позволяет своевременно решить вопрос о возможности пролонгирования беременности, что определяется видом порока, совместимостью с жизнью и прогнозом в отношении постнатального развития. В исследовании рассматриваемого порока развития большую роль играют такие современные методы, как пренатальная ультразвуковая диагностика, нейросонография, рентгеновская компьютерная и магнитно-резонансная томография головного мозга, имеющие достаточно высокую информативность. Указаны сроки гестации, позволяющие выявить структурные дефекты головного мозга. Медико-генетическое консультирование помогает выявить риск появления больного потомства. Проведена дифференциальная диагностика семилобарной с другими формами голопрозэнцефалии. Также отмечены возможные клинические проявления рассматриваемой нозологии. В данной статье представлен клинический случай семилобарной голопрозэнцефалии, диагностированной у мальчика в возрасте 1 месяц. При поступлении мать предъявляла жалобы на срыгивания и периодическое беспокойство сына. Объем и результаты обследования ребенка изложены ниже. Выявлена сопутствующая патология в виде пупочной грыжи, врожденной аномалии развития мочевой системы: подковообразная почка; водянки яичек и головчатой формы гипоспадии. После проведения курса поддерживающей терапии пациент был выписан в стабильном состоянии. В настоящее время специфическое лечение голопрозэнцефалии отсутствует. Оперативные вмешательства на головном мозге проводятся редко ввиду тяжести состояния больных, в связи с чем лечение данной патологии возможно только с помощью хирургической коррекции симптомов. Длительная дыхательная и кардиоваскулярная дисфункция предопределяет летальный исход заболевания. Since the direct etiological factors of developmental abnormalities are not known, the main groups of causes contributing to the formation of brain malformations are identified in the work. Great importance is given to the early diagnosis of malformations, which allows us to timely resolve the issue of the possibility of prolonging pregnancy, which is determined by the type of defect, compatibility with life and the prognosis for postnatal development. In the study of the considered malformation, such modern methods as prenatal ultrasound diagnostics, neurosonography, X-ray computer and magnetic resonance imaging of the brain, which have a sufficiently high informative value, play an important role. The terms of gestation are indicated, which make it possible to identify structural defects of the brain. Medical and genetic counseling helps to identify the risk of the appearance of sick offspring. The differential diagnosis of semilobar with other forms of holoprosencephaly was carried out. Possible clinical manifestations of the nosology under consideration are also noted. This article presents a clinical case of semilobar holoprosencephaly diagnosed in a boy at the age of 1 month. Upon admission, the mother complained of regurgitation and periodic anxiety of her son. The scope and results of the child's examination are set out below. Concomitant pathology was revealed in the form of an umbilical hernia, a congenital abnormality of the development of the urinary system: a horseshoe kidney; dropsy of the testicles and a cephalic form of hypospadias. After a course of maintenance therapy, the patient was discharged in a stable condition. Currently, there is no specific treatment for holoprosencephaly. Surgical interventions on the brain are rarely performed due to the severity of the patients ' condition, and therefore, the treatment of this pathology is possible only with the help of surgical correction of symptoms. Prolonged respiratory and cardiovascular dysfunction determines the fatal outcome of the disease.

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