• 대한불안의학회지
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• 제4권1호
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• pp.3-10
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• 2008

The purpose of this review was to investigate the neurophysiological and neuroimaging characteristics of patients with depression and anxiety reported in previous studies. A literature search was conducted using Medline and psychiatric textbooks. "Electroencephalography (EEG)", "Event Related Potentials (ERP)", "functional neuroimaging", "heart rate variability (HRV)" and "depression or anxiety" were used as key words. A physiological finding indicated that there was a higher degree of relativity with regards to prefrontal dysfunction in patients with depression. Right prefrontal lobe hyperactivity and left prefrontal hypoactivity were consistently observed, and abnormalities were observed in other regions (ACC, hippocampus, amygdala, etc.). Therefore, dysfunctions in these areas are related to depressive symptoms. In patients with anxiety disorder, each emotional condition showed specific activation patterns in different brain regions, such as the prefrontal cortex, occipital lobe, temporal lobe, hippocampus, and limbic system, including the amygdala. However, in the majority of patients with anxiety disorder, the degree of activation was higher in the right hemisphere than in the left hemisphere. The current data supports that there is a difference in brain dysfunction characteristics between depression and anxiety and that the different activations of various brain regions would play a significant role in the pathophysiology of depression and anxiety disorder.

• Clinical and Experimental Pediatrics
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• 제53권8호
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• pp.779-785
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• 2010

In pre-surgical evaluation of pediatric epilepsy, the combined use of multiple imaging modalities for precise localization of the epileptogenic focus is a worthwhile endeavor. Advanced neuroimaging by high field Magnetic resonance imaging (MRI), diffusion tensor images, and MR spectroscopy have the potential to identify subtle lesions. $^{18}F$-FDG positron emission tomography and single photon emission tomography provide visualization of metabolic alterations of the brain in the ictal and interictal states. These techniques may have localizing value for patients which exhibit normal MRI scans. Functional MRI is helpful for non-invasively identifying areas of eloquent cortex. These advances are improving our ability to noninvasively detect epileptogenic foci which have gone undetected in the past and whose accurate localization is crucial for a favorable outcome following surgical resection.

• 생물정신의학
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• 제18권2호
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• pp.72-79
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• 2011

Recent advances in brain imaging research are remarkable. Among them, many results from a variety of neuroimaging modalities in Alzheimer's dementia accompanied by the development and growing of imaging techniques have been presented in the research field. In this review we are focused on the imaging biomarkers for the Alzheimer's dementia to investigate the pathophysiologic mechanism. Future research on biomarkers for Alzheimer's dementia will provide more diverse and complex mechanisms or hypotheses than have been proposed in the current hypothesis about the pathogenesis of Alzheimer's dementia.

• 생물정신의학
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• 제18권2호
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• pp.61-71
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• 2011

Substance addiction is a chronically relapsing disorder that has been characterized by a vicious cycle composed of intoxication, craving/anticipation, withdrawal, and response inhibition/bingeing. Here we summarize the findings from neuroimaging studies in addiction according to these behavioral components and suggest the integrated neurobiological model of drug addiction and related brain correlates. The roles of various prefrontal regions, thalamus, memory circuit, anterior cingulated, and insula were also suggested in addition to those of classical mesolimbic dopaminergic system and its responsivity. Limited studies of behavioral addiction demonstrated a similarity with substance addiction on the neurobiological basis. Based on the current understanding of neurobiology of addiction, further researches on interactions of behavioral components and their brain correlates, behavioral addiction, and therapeutic applications will be desired.

• Applied Microscopy
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• 제46권4호
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• pp.179-183
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• 2016

Mapping brain structural and functional connections through the whole brain is essential for understanding brain mechanisms and the physiological bases of brain diseases. Although region specific structural or functional deficits cause brain diseases, the changes of interregional connections could also be important factors of brain diseases. This review will introduce common neuroimaging modalities, including structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging, and other recent neuroimaging analyses methods, such as voxel-based morphometry, cortical thickness analysis, local gyrification index, and shape analysis for structural imaging. Tract-Based Spatial Statistics, TRActs Constrained by UnderLying Anatomy for diffusion MRI, and independent component analysis for fMRI also will also be introduced.

• Journal of Neurogastroenterology and Motility
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• 제24권4호
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• pp.512-527
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• 2018

This review provides a comprehensive overview of brain imaging studies of the brain-gut interaction in functional gastrointestinal disorders (FGIDs). Functional neuroimaging studies during gut stimulation have shown enhanced brain responses in regions related to sensory processing of the homeostatic condition of the gut (homeostatic afferent) and responses to salience stimuli (salience network), as well as increased and decreased brain activity in the emotional response areas and reduced activation in areas associated with the top-down modulation of visceral afferent signals. Altered central regulation of the endocrine and autonomic nervous responses, the key mediators of the brain-gut axis, has been demonstrated. Studies using resting-state functional magnetic resonance imaging reported abnormal local and global connectivity in the areas related to pain processing and the default mode network (a physiological baseline of brain activity at rest associated with self-awareness and memory) in FGIDs. Structural imaging with brain morphometry and diffusion imaging demonstrated altered gray- and white-matter structures in areas that also showed changes in functional imaging studies, although this requires replication. Molecular imaging by magnetic resonance spectroscopy and positron emission tomography in FGIDs remains relatively sparse. Progress using analytical methods such as machine learning algorithms may shift neuroimaging studies from brain mapping to predicting clinical outcomes. Because several factors contribute to the pathophysiology of FGIDs and because its population is quite heterogeneous, a new model is needed in future studies to assess the importance of the factors and brain functions that are responsible for an optimal homeostatic state.

• Clinical and Experimental Pediatrics
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• 제63권3호
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• pp.88-95
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• 2020

Accurate localization of the seizure onset zone is important for better seizure outcomes and preventing deficits following epilepsy surgery. Recent advances in neuroimaging techniques have increased our understanding of the underlying etiology and improved our ability to noninvasively identify the seizure onset zone. Using epilepsy-specific magnetic resonance imaging (MRI) protocols, structural MRI allows better detection of the seizure onset zone, particularly when it is interpreted by experienced neuroradiologists. Ultra-high-field imaging and postprocessing analysis with automated machine learning algorithms can detect subtle structural abnormalities in MRI-negative patients. Tractography derived from diffusion tensor imaging can delineate white matter connections associated with epilepsy or eloquent function, thus, preventing deficits after epilepsy surgery. Arterial spin-labeling perfusion MRI, simultaneous electroencephalography (EEG)-functional MRI (fMRI), and magnetoencephalography (MEG) are noinvasive imaging modalities that can be used to localize the epileptogenic foci and assist in planning epilepsy surgery with positron emission tomography, ictal single-photon emission computed tomography, and intracranial EEG monitoring. MEG and fMRI can localize and lateralize the area of the cortex that is essential for language, motor, and memory function and identify its relationship with planned surgical resection sites to reduce the risk of neurological impairments. These advanced structural and functional imaging modalities can be combined with postprocessing methods to better understand the epileptic network and obtain valuable clinical information for predicting long-term outcomes in pediatric epilepsy.

• 생물정신의학
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• 제22권3호
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• pp.101-108
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• 2015

Recent breakthroughs in functional neuroimaging techniques have launched the quest of mapping the connections of the human brain, otherwise known as the human connectome. Imaging connectomics is an umbrella term that refers to the neuroimaging techniques used to generate these maps, which recently has enabled comprehensive brain mapping of network connectivity combined with graph theoretic methods. In this review, we present an overview of the key concepts in functional connectomics. Furthermore, we discuss articles that applied task-based and/or resting-state functional magnetic resonance imaging to examine network deficits in post-traumatic stress disorder (PTSD). These studies have provided important insights regarding the etiology of PTSD, as well as the overall organization of the brain network. Advances in functional connectomics are expected to provide insight into the pathophysiology and the development of biomarkers for diagnosis and treatment of PTSD.

• Journal of Korean Neurosurgical Society
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• 제48권4호
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• pp.375-379
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• 2010

The Chiari 1.5 malformation is defined as a tonsillar hemiation within a Chiari I malformation with additional caudal descent of the brainstem through the foramen magnum. We describe a patient with Chiari I malformation who evolved to Chiari 1.5 malformation during longitudinal follow-up. A 15-year-old girl presented with neck pain during exercise for two years. She had been diagnosed with Chiari I malformation with mild hydrocephalus after minor cervical trauma at the age of six years. At that time, she was asymptomatic. After she complained of aggravated neck pain, neuroimaging (nine years after first imaging) revealed caudal descent of the brainstem and syringomyelia in addition to progression of tonsillar hemiation. Posterior fossa decompressive surgery resulted in complete resolution of neck pain. Based on neuroimaging and operative findings, she was diagnosed as Chiari 1.5 malformation. Neuroimaging performed seven months after surgery showed an increased anterior-posterior diameter of the medulla oblongata and markedly decreased syringomyelia. This case demonstrates progressive developmental process of the Chiari 1.5 malformation as an advanced form of the Chiari I malformation.

• Journal of Yeungnam Medical Science
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• 제22권2호
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• pp.119-130
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• 2005

Stroke is a leading cause of chronic physical disability. The recent randomized controlled trials have that motor function of chronic stroke survivors could be improved through physical or pharmacologic intervention in the stroke rehabilitation setting. In addition, several functional neuroimaging techniques have recently developed, it is available to study the functional topography of sensorimotor area of the brain. However, the mechanisms involved in motor recovery after stroke, are still poorly understood. Four motor recovery mechanisms have been suggested, such as reorganization into areas adjacent to the injured primary motor cortex (M1), unmasking of the motor pathway from the unaffected motor cortex to the affected hand, attribution of secondary motor areas, and recovery of the damaged contralateral corticospinal tract. Understanding the motor recovery mechanisms would provide neurorehabilitation specialists with more information to allow for precise prognosis and therapeutic strategies based on the scientific evidence; this may help promote recovery of motor function. This review introduces several methodologies for neuroimaging techniques and discusses theoretical issues that impact interpretation of functional imaging studies of motor recovery after stroke. Perspectives, for future research are presented.