Neuroimaging of Epilepsy

Author(s):  
William A. Gomes

Neuroimaging is essential for clinical care and basic research in epilepsy. MRI is the primary tool, but adjunctive techniques are commonly employed including MRS, PET, SPECT, and MEG. These techniques facilitate localization and characterization of seizure foci prior to epilepsy surgery, and also allow preoperative assessment of risk to eloquent brain regions. Evaluation of patients with MRI-negative epilepsy remains a major clinical challenge and motivation for contemporary research.

2021 ◽  
Vol 4 ◽  
pp. 205920432110101
Author(s):  
Gonçalo T. Barradas ◽  
Patrik N. Juslin ◽  
Sergi Bermúdez i Badia

Music is frequently regarded as a unique way to connect with dementia patients. Yet little is known about how persons with dementia respond emotionally to music. Are their responses different from those of healthy listeners? If so, why? The present study makes a first attempt to tackle these issues in a Portuguese context, with a focus on psychological mechanisms. In Experiment 1, featuring 20 young and healthy adults, we found that musical excerpts which have previously been shown to activate specific emotion induction mechanisms (brain stem reflex, contagion, episodic memory, musical expectancy) in Sweden were valid and yielded predicted emotions also in Portugal, as indexed by self-reported feelings, psychophysiology, and post hoc mechanism indices. In Experiment 2, we used the same stimuli to compare the responses of 20 elderly listeners diagnosed with Alzheimer’s disease (AD) with those of 20 healthy listeners. We controlled for cognitive functioning (Mini-Mental State Examination) and depression (Geriatric Depression Scale). Our predictions about how mechanisms would be differentially affected by decline in brain regions associated with AD received support in that AD patients reported significantly lower levels of (a) sadness in the contagion condition, (b) happiness and nostalgia in the episodic memory condition, and (c) anxiety in the musical expectancy condition. By contrast, no significant difference in reported surprise was found in the brain stem reflex condition. Implications for musical interventions aimed at dementia are discussed, highlighting the key role that basic research may play in developing applications.


2011 ◽  
Vol 5 (4) ◽  
pp. 310-321
Author(s):  
Eduardo Moreira de Oliveira ◽  
Priscilla Tiemi Kissaki ◽  
Tiago Nascimento Ordonez ◽  
Thaís Bento Lima-Silva

Abstract A systematic review of the neuroanatomical literature was performed to determine the neuropharmacological aspects most relevant to the study of memory processes. Articles were retrieved using the search terms "biology of memory", "memory and aging", "memory impairment", "elderly and memory," and their equivalents in Portuguese. Of the studies surveyed, five studies dealt with epidemiological and demographic issues, 12 were clinical trials i.e. were based on testing and implementation of instruments in human subjects, 33 studies were basic research involving studies of mice, rats and non-human primates, and biochemical and in vitro trials and finally, 52 studies were literature reviews or book chapters which in our view, fell into this category. Conclusions: The work sought to highlight which neural networks are most involved in processing information, as well as their location within brain regions and the way in which neurotransmitters interact with each other for the formation of these memories. Moreover, it was shown how memory changes during the normal human aging process, both positively and negatively, by analyzing the morphological alterations that occur in the brain of aging individuals.


Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 105 ◽  
Author(s):  
Maria Zella ◽  
Judith Metzdorf ◽  
Friederike Ostendorf ◽  
Fabian Maass ◽  
Siegfried Muhlack ◽  
...  

The etiology of Parkinson’s disease (PD) is significantly influenced by disease-causing changes in the protein alpha-Synuclein (aSyn). It can trigger and promote intracellular stress and thereby impair the function of dopaminergic neurons. However, these damage mechanisms do not only extend to neuronal cells, but also affect most glial cell populations, such as astroglia and microglia, but also T lymphocytes, which can no longer maintain the homeostatic CNS milieu because they produce neuroinflammatory responses to aSyn pathology. Through precise neuropathological examination, molecular characterization of biomaterials, and the use of PET technology, it has been clearly demonstrated that neuroinflammation is involved in human PD. In this review, we provide an in-depth overview of the pathomechanisms that aSyn elicits in models of disease and focus on the affected glial cell and lymphocyte populations and their interaction with pathogenic aSyn species. The interplay between aSyn and glial cells is analyzed both in the basic research setting and in the context of human neuropathology. Ultimately, a strong rationale builds up to therapeutically reduce the burden of pathological aSyn in the CNS. The current antibody-based approaches to lower the amount of aSyn and thereby alleviate neuroinflammatory responses is finally discussed as novel therapeutic strategies for PD.


2003 ◽  
Vol 60 (3) ◽  
pp. 353-360
Author(s):  
Milomir Djokic ◽  
Vesna Begovic ◽  
Radmila Rajic-Dimitrijevic ◽  
Rada Aleksic ◽  
Svetlana Popovic ◽  
...  

Fulminant hepatitis, or fulminant hepatic failure, is defined as a clinical syndrome of severe liver function impairment, which causes hepatic coma and the decrease in synthesizing capacity of liver, and develops within eight weeks of the onset of hepatitis. Several independent factors influence the survival of patients: age, the cause of liver disease, the degree and the duration of encephalopathy in relation to the onset of the disease, and the prevention of complications. Over the years many intensive treatments have been practiced. Liver transplantation is expensive, and patients who survive transplantation require life-long immunosupression, clinical care and complications management. Without transplantation fulminant hepatitis and hepatic failure might be completely recovered spontaneously, and the patient could expect a normal life. Two cases of fulminant B hepatitis with intensive care treatment, and their survival despite unfavorable prognosis are presented in this paper. The menagement of patients with fulminant hepatitis required intensive monitoring and therapeutic measures, including corticosteroids. The prognosis for survival without transplantation in fulminant hepatitis is limited by the measures of medical treatment and new specific therapeutic modalities which must be developed through basic research.


2021 ◽  
Vol 15 ◽  
Author(s):  
Paolo Finotelli ◽  
Carlo Piccardi ◽  
Edie Miglio ◽  
Paolo Dulio

In this paper, we propose a graphlet-based topological algorithm for the investigation of the brain network at resting state (RS). To this aim, we model the brain as a graph, where (labeled) nodes correspond to specific cerebral areas and links are weighted connections determined by the intensity of the functional magnetic resonance imaging (fMRI). Then, we select a number of working graphlets, namely, connected and non-isomorphic induced subgraphs. We compute, for each labeled node, its Graphlet Degree Vector (GDV), which allows us to associate a GDV matrix to each one of the 133 subjects of the considered sample, reporting how many times each node of the atlas “touches” the independent orbits defined by the graphlet set. We focus on the 56 independent columns (i.e., non-redundant orbits) of the GDV matrices. By aggregating their count all over the 133 subjects and then by sorting each column independently, we obtain a sorted node table, whose top-level entries highlight the nodes (i.e., brain regions) most frequently touching each of the 56 independent graphlet orbits. Then, by pairwise comparing the columns of the sorted node table in the top-k entries for various values of k, we identify sets of nodes that are consistently involved with high frequency in the 56 independent graphlet orbits all over the 133 subjects. It turns out that these sets consist of labeled nodes directly belonging to the default mode network (DMN) or strongly interacting with it at the RS, indicating that graphlet analysis provides a viable tool for the topological characterization of such brain regions. We finally provide a validation of the graphlet approach by testing its power in catching network differences. To this aim, we encode in a Graphlet Correlation Matrix (GCM) the network information associated with each subject then construct a subject-to-subject Graphlet Correlation Distance (GCD) matrix based on the Euclidean distances between all possible pairs of GCM. The analysis of the clusters induced by the GCD matrix shows a clear separation of the subjects in two groups, whose relationship with the subject characteristics is investigated.


2020 ◽  
Vol 12 ◽  
pp. 175628722091661 ◽  
Author(s):  
Andrea Haren ◽  
Rajni Lal ◽  
David Walker ◽  
Rajesh Nair ◽  
Judith Partridge ◽  
...  

Background: Radical cystectomy (RC) and urinary diversion are the recommended treatment for patients with muscle invasive bladder cancer. This is complex surgery, associated with significant patient morbidity and mortality. Frailty has been shown to be an independent risk factor for adverse outcomes in several surgical populations. Preoperative assessment of frailty is advocated in current guidelines but is not yet standard clinical practice. Aims: This systematic review and narrative synthesis aims to examine whether patients undergoing RC are assessed for frailty, what tools are used, and whether an association is found between frailty and adverse outcomes in this population. Results: Nine studies, published within the last 4 years, describe the use of tools reporting to measure frailty in the RC population. All demonstrate increased risk of adverse postoperative outcomes with higher frailty levels. Only one study used a validated frailty tool. The majority of studies measure frailty using variations on a tool derived from a large database (ACS-NSQIP) effectively counting co-morbidities, rather than assessing the multidomain nature of the frailty syndrome. Conclusion: The recognition of frailty as an important consideration in the perioperative period is welcome. This systematic review and narrative synthesis demonstrates the need for collaboration in research and delivery of clinical care for older surgical patients. Such collaboration may provide clarity regarding terms such as frailty and multimorbidity, preventing the development of assessment tools inaccurately measuring these discreet syndromes interchangeably. More accurate assessment of patients in terms of frailty, multimorbidity and functional status may allow better modification and shared decision making leading to improved postoperative outcomes in older patients undergoing RC.


Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 681
Author(s):  
Junhao Sun ◽  
Xu Han ◽  
Guanrui Song ◽  
Qianhong Gong ◽  
Wengong Yu

Glycosaminoglycan (GAG) lyase is an effective tool for the structural and functional studies of glycosaminoglycans and preparation of functional oligosaccharides. A new GAG lyase from Microbacterium sp. H14 was cloned, expressed, purified, and characterized, with a molecular weight of approximately 85.9 kDa. The deduced lyase HCLaseM belonged to the polysaccharide lyase (PL) family 8. Based on the phylogenetic tree, HCLaseM could not be classified into the existing three subfamilies of this family. HCLaseM showed almost the same enzyme activity towards hyaluronan (HA), chondroitin sulfate A (CS-A), CS-B, CS-C, and CS-D, which was different from reported GAG lyases. HCLaseM exhibited the highest activities to both HA and CS-A at its optimal temperature (35 °C) and pH (pH 7.0). HCLaseM was stable in the range of pH 5.0–8.0 and temperature below 30 °C. The enzyme activity was independent of divalent metal ions and was not obviously affected by most metal ions. HCLaseM is an endo-type enzyme yielding unsaturated disaccharides as the end products. The facilitated diffusion effect of HCLaseM is dose-dependent in animal experiments. These properties make it a candidate for further basic research and application.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi170-vi171
Author(s):  
Jay Patel ◽  
Andrew Beers ◽  
Ken Chang ◽  
James Brown ◽  
Katharina Hoebel ◽  
...  

Abstract PURPOSE Measuring treatment response is vital for assessing efficacy of treatment regimen for patients with brain metastases (BM). Unfortunately, manual delineation of all lesions on MRI across time-points is prohibitively time-consuming, making it infeasible to track individual lesion growth/shrinkage rates as part of the clinical workflow. To overcome this challenge, we propose a deep learning approach to segment all BM, and furthermore, show that certain brain regions are more prone to high-growth rate lesions. METHODS 163 longitudinal MRIs from 77 patients with MPRAGE-post contrast imaging protocol were prospectively obtained from Massachusetts General Hospital (MGH). An expert neuro-oncologist provided ground truth segmentations for all patients. A 3D U-Net architecture was trained to automatically segment BM; training was stopped when validation set Dice score plateaued to prevent overfitting. To enable lesion tracking, all time-points per patient were affinely registered to each other. Every lesion was subsequently classified based on its growth rate (responder: overall lesion shrinkage; inconclusive: 0% to 40% lesion growth; non-responder: more than 40% lesion growth). Characterization of global lesion growth rate patterns was accomplished by affinely registering all time-points to the MNI brain atlas. Segmented lesions were projected onto the atlas, which was qualitatively analyzed to identify spatial regions composed primarily of one class of lesion. RESULTS For automatic segmentation, we report a mean dice score of 0.778, 0.737, and 0.704 on training, validation, and testing sets respectively. Furthermore, we find that the largest BM with the highest average growth rate (non-responders) tend to be located in the posterior frontal/parietal lobes, while smaller, lower growth rate lesions (responders) tend to be localized in the frontal lobes. The posterior fossa was found to be heterogeneous in lesion size and growth rate. CONCLUSION We developed automatic metastatic lesion tracking over time-points and identified brain regions associated with differing growth rate lesions.


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