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.
Biomarkers ; Brain ; Brain Mapping ; Connectome* ; Diagnosis ; Functional Neuroimaging ; Humans ; Magnetic Resonance Imaging ; Neuroimaging ; Neurosciences* ; Stress Disorders, Post-Traumatic*

INTRODUCTION: This article reviews the health effects of manganese (Mn) and introduces readers to recent issues in Mn neurotoxicity research. METHODS: An extensive Medline search that covered publications up to December 2008 was conducted and the relevant papers and their references were evaluated for review. RESULTS AND DISCUSSION: Exposure to excess levels of the essential trace element Mn produces cognitive, psychiatric, and motor abnormalities. The lungs and the gastrointestinal tract both absorb Mn, but homeostatic mechanisms limit the absorption of Mn by the gastrointestinal tract. Elimination of Mn occurs primarily by excretion into the bile. Average Mn levels in the blood reflect the total body burden on a group basis, but not on an individual basis. Previous studies have shown that blood Mn contributes to a high pallidal signal in a T1-weighted brain MRI and that the high signal is an effective predictor of neurobehavioral performance. Thus, a high pallidal signal on an MRI may offer clues concerning the target organ dose from Mn exposure in the spectrum of Mn symptomatology. Neuroimaging as well as a clinical evaluation with exposure history is very important in a differential diagnosis that can distinguish manganism from Parkinson disease (PD). Recent research on Mn neurotoxicity has focused on several issues. First, concerns about the interaction between manganism and PD have been raised, but further research is needed. Second, epidemiological studies on non-occupational Mn exposure have suggested that environmentally induced neurotoxicities may have features that are different from the classic features of occupational manganism, but, again, this requires further research. Third, liver cirrhosis could be used as a model of manganism. Finally, functional neuroimaging such as magnetic resonance spectroscopy, functional MRI, or diffusion tensor imaging appears to have promising applications in Mn research. CONCLUSION: Reviewing the health effects of Mn and recent issues in Mn neurotoxicity research provides us with important suggestions for how to pursue other lines of toxicological research as well as for how best to develop a systematic understanding of Mn symptomatology.
Absorption ; Bile ; Body Burden ; Brain ; Diagnosis, Differential ; Diffusion Tensor Imaging ; Functional Neuroimaging ; Gastrointestinal Tract ; Liver Cirrhosis ; Lung ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Manganese ; Neuroimaging ; Parkinson Disease

Systems-based approaches to neuroscience, using network analysis and the human connectome, have been adopted by many researchers by virtue of recent progress in neuroimaging and computational technologies. Various neurological disorders have been evaluated from a network perspective, including stroke, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. Until now, dynamic processes after stroke and during recovery were investigated through multimodal neuroimaging techniques. Many studies have shown disruptions in structural and functional connectivity, including in large-scale neural networks, in patients with stroke sequela such as motor weakness, aphasia, hemianopia, neglect, and general cognitive dysfunction. A connectome-based approach might shed light on the underlying mechanisms of stroke sequela and the recovery process, and could identify candidates for individualized rehabilitation programs. In this review, we briefly outline the basic concepts of structural and functional connectivity, and the connectome. Then, we explore current evidence regarding how stroke lesions cause changes in connectivity and network architecture parameters. Finally, the clinical implications of perspectives on the connectome are discussed in relation to the cognitive and behavioral sequela of stroke.
Alzheimer Disease ; Aphasia ; Brain Injuries ; Connectome* ; Diffusion Tensor Imaging ; Hemianopsia ; Humans ; Nervous System Diseases ; Neuroimaging ; Neurosciences ; Parkinson Disease ; Rehabilitation ; Stroke* ; Virtues

With the structural and functional neuroimaging studies on alcohol use disorders, the neurobiology of alcohol use disorder can now be directly measured in vivo. This article reviews the findings of structural and functional neuroimaging studies related to alcohol use disorder. Issues about intoxication, dependence, withdrawal, abstinence, organic change induced by chronic alcohol use, neurochemistry and craving are discussed and its clinical implications and future direction of neuroimaging studies are also suggested.
Functional Neuroimaging ; Neurobiology ; Neurochemistry ; Neuroimaging*

Neuroimaging studies in schizophrenia have remarkably increased and provided some clues to understand its pathophysiology. Here, we reviewed the neuroimaging, studies including volume analysis, functional magnetic resonance imaging (MRI) and diffusion tensor imaging, and findings in both early stage schizophrenia and high-risk group. The reviewed studies suggested that the brain with schizophrenia showed both regional deficits and dysconnectivity of neural circuit in the first episode, even high-risk group as well as chronic schizophrenia. Multimodal neuroimaging or combined approach with genetic, electro- or magneto-encephalographic data could provide promising results to understand schizophrenia in the near future.
Brain ; Diffusion Tensor Imaging ; Magnetic Resonance Imaging ; Neuroimaging ; Schizophrenia

Neuroimaging in psychiatry encompasses the powerful tools available for the in vivo study of brain structure and function. MRI including the volumetry, voxel-base morphometry(VBM) and diffusion tensor imaging (DTI) are useful for assessing brain structure, whereas function MRI, positron emission tomography(PET) and magnetoencephalography(MEG) are well established for probing brain function. These tools are well tolerated by the vast majority of psychiatric patients because they provide a powerful but noninvasive means to directly evaluate the brain. Although neuroimaging technology is currently used only to rule in or rule out general medical conditions as opposed to diagnosing primary mental disorders, it may be used to confirm or make psychiatric diagnoses in the future. In addition, neuroimaging may be valuable for predicting the natural course of psychiatric illness as well as treatment response.
Brain ; Diffusion Tensor Imaging ; Electrons ; Humans ; Mental Disorders ; Neuroimaging

No abstract available.
Functional Neuroimaging ; Neurotology

No abstract available.
Epilepsy* ; Functional Neuroimaging*

Non-pulsatile subjective tinnitus is a phantom sound percept without any objective physical sound source. Recent advances in tinnitus research have suggested central rather than peripheral changes as the culprit of tinnitus perception. Moreover, researchers have shown that these central functional changes can be observed not only in the auditory cortex but also in non-auditory regions such as the frontal, parietal, and limbic areas in patients with tinnitus. In this regard, functional neuroimaging modalities such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and quantitative electroencephalography (qEEG) provided researchers with a window into the cerebral cortical activity orchestrating tinnitus. Among these methods, qEEG and MEG are advantageous over PET or fMRI with regard to temporal resolution, while PET and fMRI are advantageous over qEEG or MEG with regard to spatial resolution. In other words, there is no gold standard functional neuroimaging modality in the field of tinnitus, but these four modalities are complementary to one another. In this review article, these four representative functional neuroimaging modalities and their application to tinnitus research will be introduced. Moreover, future direction of functional neuroimaging research on the pathophysiology of tinnitus will be discussed briefly.
Auditory Cortex ; Brain Mapping ; Electroencephalography ; Functional Neuroimaging* ; Humans ; Magnetic Resonance Imaging ; Magnetoencephalography ; Positron-Emission Tomography ; Rabeprazole ; Tinnitus*

With the rise of aging population, clinical concern and research attention has shifted towards neuroimaging of dementia. The advent of 3T, magnetic resonance imaging (MRI) has permitted the anatomical imaging of neurodegenerative disease, specifically dementia, with improved resolution. Furthermore, more powerful techniques such as diffusion tensor imaging, quantitative susceptibility mapping, and magnetic transfer imaging have successfully emerged for the detection of micro-structural abnormalities. In the present review article, we provide a brief overview of Alzheimer's disease and explore recent neuroimaging developments in the field of dementia with an emphasis on structural MR imaging in order to propose a simple and easily applicable systematic approach to the imaging diagnosis of dementia.
Aging ; Alzheimer Disease* ; Dementia* ; Diagnosis* ; Diffusion Tensor Imaging ; Magnetic Resonance Imaging* ; Neurodegenerative Diseases ; Neuroimaging