Characteristics of Telepresence by Multisensory Feedback and Related Neural Mechanism in Patients with Schizophrenia : A Functional MRI Study

OBJECTIVES: The multimodal telepresence systems have been adopted in a variety of applications, such as telemedicine, space or underwater teleoperation and videoconference. Multimedia, one of the telepresence systems, has been used in various fields including entertainment, education and communication. The degree of subjective telepresence is defined as the probability that a person perceives to be physically in the remote place when he/she experiences a multisensory feedback from the multimedia. The current study aimed to explore the neural mechanism of telepresence related to multisensory feedback in patients with schizophrenia. METHODS: Brain activity was measured using functional magnetic resonance imaging while fifteen healthy controls and fifteen patients with schizophrenia were experiencing filmed referential conversation at various distances (1 m, 5 m and 10 m). Correlations between the image contrast values and the telepresence scores were analyzed. RESULTS: Subjective telepresence was not significantly different between the two groups. Some significant correlations of brain activities with the telepresence scores were found in the left postcentral gyrus, bilateral inferior frontal gyri, right fusiform gyrus, and left superior temporal sulcus. There were no main effects of group and distance. CONCLUSION: These results suggest that patients with schizophrenia experience telepresence as appropriately as healthy people do when exposed to multimedia. Therefore, patients with schizophrenia would have no difficulty in immersing themselves in multimedia which may be used in clinical training therapies.

Upper Extremity Proprioceptive Assessment Test Using Virtual Environment Technique in Patients with Stroke

OBJECTIVE: To examine the reliability of upper extremity proprioceptive assessment test using virtual environment technique (VET) in patients with stroke with test-retest paradigm and define criterion for normal value by comparing with unimpaired control group. METHOD: Thirty stroke patients and 30 control groups were recruited. The VET apparatus is consisted of virtual reality upper extremity tester (VRUPT), encoder, and head-mounted display (HMD). VET-based test is composed of two tasks. Angle assessment task is required matching of imposed joint positions without visual feedback for checking angle error. Reaching assessment task is required matching of imposed cylinder with visual feedback for checking time, number of click, total interaction error. RESULTS: In the test-retest analysis, correlation coefficients ranged from 0.73 to 0.99 (p<0.01). Significant differences consistently found between affected upper extremity joint of stroke group and corresponding upper extremity joint of control group for the major variables (p<0.05). The cut off value in shoulder, elbow, wrist joints were calculated as 8.24degrees, 8.41degrees, 10.31degrees and the frequency of proprioceptive abnormalities based on these cut off value of angle error in shoulder, elbow, wrist joints showed 60%, 67%, 83% respectively, in our stroke group. CONCLUSION: This VET-based proprioceptive assessment test shows promise in assessing proprioception in patients with stroke more objectively and quantitatively.

Virtual Reality for Obsessive-Compulsive Disorder: Past and the Future

The use of computers, especially for virtual reality (VR), to understand, assess, and treat various mental health problems has been developed for the last decade, including application for phobia, post-traumatic stress disorder, attention deficits, and schizophrenia. However, the number of VR tools addressing obsessive-compulsive disorder (OCD) is still lacking due to the heterogeneous symptoms of OCD and poor understanding of the relationship between VR and OCD. This article reviews the empirical literatures for VR tools in the future, which involve applications for both clinical work and experimental research in this area, including examining symptoms using VR according to OCD patients' individual symptoms, extending OCD research in the VR setting to also study behavioral and physiological correlations of the symptoms, and expanding the use of VR for OCD to cognitive-behavioral intervention.

Hierarchical Classification of ECG Beat Using Higher Order Statistics and Hermite Model / 대한의료정보학회지

OBJECTIVE: The heartbeat classification of the electrocardiogram is important in cardiac disease diagnosis. For detecting QRS complex, conventional detection algorithmhave been designed to detect P, QRS, Twave, first. However, the detection of the P and T wave is difficult because their amplitudes are relatively low, and occasionally they are included in noise. Furthermore the conventionalmulticlass classificationmethodmay have skewed results to themajority class, because of unbalanced data distribution. METHODS: The Hermite model of the higher order statistics is good characterization methods for recognizing morphological QRS complex. We applied three morphological feature extraction methods for detecting QRS complex: higher-order statistics, Hermite basis functions andHermitemodel of the higher order statistics.Hierarchical scheme tackle the unbalanced data distribution problem. We also employed a hierarchical classification method using support vector machines. RESULTS:We compared classification methods with feature extraction methods. As a result, our mean values of sensitivity for hierarchical classification method (75.47%, 76.16% and 81.21%) give better performance than the conventionalmulticlass classificationmethod (46.16%). In addition, theHermitemodel of the higher order statistics gave the best results compared to the higher order statistics and the Hermite basis functions in the hierarchical classification method. CONCLUSION: This research suggests that the Hermite model of the higher order statistics is feasible for heartbeat feature extraction. The hierarchical classification is also feasible for heartbeat classification tasks that have the unbalanced data distribution.

Voxel-Based Morphometry Study of Gray Matter Abnormalities in Obsessive-Compulsive Disorder

To examine regional abnormalities in the brains of patients with obsessive-compulsive disorder (OCD), we assessed the gray matter (GM) density using voxel-based morphometry (VBM). We compared magnetic resonance images (MRIs) acquired from 71 OCD patients and 71 age- and gender-matched normal controls and examined the relationship between GM density and various clinical variables in OCD patients. We also investigated whether GM density differs among the subtypes of OCD compared to healthy controls. We detected significant reduction of GM in the inferior frontal gyrus, the medial frontal gyrus, the insula, the cingulate gyrus, and the superior temporal gyrus of OCD patients. A significant increase in GM density was observed in the postcentral gyrus, the thalamus, and the putamen. Some of these regions, including the insular and postcentral gyrus, were also associated with the severity of obsessive- compulsive symptoms. These findings indicate that the frontal-subcortical circuitry is dysfunctional in OCD, and suggest that the parietal cortex may play a role in the pathophysiology of this disease.

The Relationship between Cortical Activation during an Inference Task and Presence in the Virtual Environment in Patients with Schizophrenia: An fMRI Study / 신경정신의학

OBJECTIVES: Virtual reality has been increasingly used in the psychiatric field. Presence, the sense of "being there," is an essential concept in terms of the effectiveness of the virtual reality. The present study aimed to investigate the characteristics of the presence-related brain regions in patients with schizophrenia. METHODS: Using fMRI, brain activities were measured while performing the virtual reality tasks in fifteen healthy normal subjects and fifteen patients with schizophrenia. The tasks consisted of listening to some stories and inferring the content of the previous events. Ambiguous information was given for the experimental task, whereas clear information was given for the control task. Correlations between the image contrast values and the presence scores were analyzed. RESULTS: The presence-related brain regions in healthy controls were identified in the two discrete region groups that could be referred to as the cognitive neural correlates and the perceptual neural correlates. The former included the anterior cingulate, the left inferior temporal gyrus, the right lingual gyrus, and the right cuneus, whereas the latter consisted of the right posterior cingulate, the left lingual gyrus and the right fusiform gyrus. Compared with healthy controls, regional correlation patterns were different in patients with schizophrenia, including that the posterior cingulate had significant correlations. CONCLUSION: These results suggest that patients with schizophrenia utilize perceptual apparatus for the presence more than the cognitive aspect. A peculiar pattern of the presence in schizophrenia may be related to increased correlations between the posterior cingulate and other brain regions.

Social Pressure-Induced Craving in Patients with Alcohol Dependence: Application of Virtual Reality to Coping Skill Training

OBJECTIVE: This study was conducted to assess the interaction between alcohol cues and social pressure in the induction of alcohol craving. METHODS: Fourteen male patients with alcohol dependence and 14 age-matched social drinkers completed a virtual reality coping skill training program composed of four blocks according to the presence of alcohol cues (x2) and social pressure (x2). Before and after each block, the craving levels were measured using a visual analogue scale. RESULTS: Patients with alcohol dependence reported extremely high levels of craving immediately upon exposure to a virtual environment with alcohol cues, regardless of social pressure. In contrast, the craving levels of social drinkers were influenced by social pressure from virtual avatars. CONCLUSION: Our findings imply that an alcohol cue-laden environment should interfere with the ability to use coping skills against social pressure in real-life situations.

The Interchange of Radiological Reports Using Clinical Document Architecture Standards / 대한의료정보학회지

OBJECTIVE: We developed a Clinical Document Architecture(CDA) Generator module based on CDA standard for the interchange of radiological reports. METHODS: This paper describes CDA standard, the template of radiological report, CDA Generator module, and the Web-form report using an Extensible Stylesheet Language(XSL) style-sheet. And the CDA Generator module is integrated into a existing Picture Archiving Communication System(PACS) Viewer. RESULTS: Radiological reports based on CDA standard are used to interchange between different health institutions, and also presented in an Extensible Markup Language (XML) compatible web browser. CONCLUSION: The proposed module and concept in this paper may be a utility in improving health care delivery and can also be used to integrate with other Digital Imaging and Communication in Medicine(DICOM) Structured Report (SR) compliant PACS systems.

Structural Brain Abnormalities in Juvenile Myoclonic Epilepsy Patients: Volumetry and Voxel-Based Morphometry

OBJECTIVE: We aimed to find structural brain abnormalities in juvenile myoclonic epilepsy (JME) patients. MATERIALS AND METHODS: The volumes of the cerebrum, hippocampus and frontal lobe and the area of the corpus callosum's subdivisions were all semi-automatically measured, and then optimized voxel-based morphometry (VBM) was performed in 19 JME patients and 19 age/gender matched normal controls. RESULTS: The rostrum and rostral body of the corpus callosum and the left hippocampus were significantly smaller than those of the normal controls, whereas the volume of the JME's left frontal lobe was significantly larger than that of the controls. The area of the rostral body had a significant positive correlation with the age of seizure onset (r = 0.56, p = 0.012), and the volume of the right frontal lobe had a significant negative correlation with the duration of disease (r = -0.51, p = 0.025). On the VBM, the gray matter concentration of the prefrontal lobe (bilateral gyri rectus, anterior orbital gyri, left anterior middle frontal gyrus and right anterior superior frontal gyrus) was decreased in the JME group (corrected p < 0.05). CONCLUSION: The JME patients showed complex structural abnormalities in the corpus callosum, frontal lobe and hippocampus, and also a decreased gray matter concentration of the prefrontal region, which all suggests there is an abnormal neural network in the JME brain.

The Study on Classification Method of Obsessive-Compulsive Disorder with Schizotypal Trait using Frontal Lobe Function Test / 대한의료정보학회지

OBJECTIVE: The identifying schizotypal trait in obsessive-compulsive disorder (OCD) patients is important to predict clinical course, since those patients are hardly overcome through conventional intervention methods. This paper presents the trial of classification method of obsessive-compulsive disorder with schizotypal trait using Frontal Lobe Function Test (FLFT). METHODS: 110 OCD patients are divided into two groups:27 pure OCD patients, and 83 non-pure OCD patients. After training artificial neural network (ANN) using frontal-lobe function test data of train data (schizophrenia, pure OCD, and normal group), we classify test data (non-pure OCD patients) into one of the three groups. RESULTS: Among the total 83 test data (non-pure OCD patients), 44 patients were classified as schizophrenia, 32 patients as normal, and 7 patients as pure OCD. With respect to the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) data of those classified patients, ordering score in compulsion was significantly different between three groups. Moreover, cluster A socre (Schizoid, Schizotypal) of Personality Diagnostic Questionnaire (PDQ) data showed significant difference between them. CONCLUSION: The results presented that those OCD patients who are classified as schizophrenia using generated model with machine learning technique is tend to have compulsive symptom of arrangement and schizotypal personality disorder.

Assessment of Post-stroke Unilateral Neglect Using 3-Dimensional Virtual Reality Program

OBJECTIVE: To investigate the clinical usefulness of newly developed 3-dimensional virtual reality (VR) program to assess the unilateral neglect. METHOD: Sixteen unilateral neglect patients and forty healthy subjects were included in this study. Forty healthy subjects were classified into two groups (control group I, II) based on the previous computer experience. This VR program was composed of two sessions, the first session was to search the midpoint of the monitor and the second session was to scan the randomized target movement. Head-mounted display and 3-dimensional position sensor were used during VR program. The unilateral neglect patients performed the line bisection test and the letter cancellation test. The correlations of the clinical measurements and the parameters of the 3-dimensional VR program were analyzed. RESULTS: All parameters of the VR program in patient group were significantly different with those in control group I, II (p <0.05). Left directional parameters were significantly different with right directional parameters of the VR program in patient group (p <0.05), but not in control group I, II. The parameters of the VR program were significantly correlated with clinical measurements (p <0.05). CONCLUSION: The assessment of unilateral neglect using 3- dimensional virtual reality program may be clinically useful.

Development of Korean Standard Brain Templates

We developed age, gender and ethnic specific brain templates based on MR and Positron-Emission Tomography (PET) images of Korean normal volunteers. Seventy-eight normal right-handed volunteers (M/F=49/29) underwent 3D T1-weighted SPGR MR and F-18-FDG PET scans. For the generation of standard templates, an optimal target brain that has the average global hemispheric shape was selected for each gender. MR images were then spatially normalized by linear transformation to the target brains, and normalization parameters were reapplied to PET images. Subjects were subdivided into 2 groups for each gender: the young/midlife (<55 yr) and the elderly groups. Young and elderly MRI/PET templates were composed by averaging the spatially normalized images. Korean templates showed different shapes and sizes (mean length, width, and height of the brains were 16.5, 14.3 and 12.1 cm for man, and 15.6, 13.5 and 11.4 cm for woman) from the template based on Caucasian (18.3, 14.2, and 13.3 cm). MRI and PET templates developed in this study will provide the framework for more accurate stereotactic standardization and anatomical localization.

The Contemplation of Neuropathological Abnormalities of the Corpus Callosum in Schizophrenia: A Diffusion Tensor Imaging Study / 신경정신의학

OBJECTIVES: Diffusion tensor imaging (DTI) is a new technique that can be used to visualize and measure the diffusion of water in brain tissue. It is particularly useful for evaluating white matter abnormalities. In this paper, we investigated the neuropathology of the corpus callosum in patients with schizophrenia through the new methods, diffusion tensor imaging. METHODS: Diffuse tensor imaging was performed in 19 schizophrenic patients and 26 healthy controls. One complementary measure, fractional anisotropy (FA), which is considered to be sensitive indices of axonal integrity, was obtained from regions of interest in the five areas of the corpus callosum. Neuropsychological measurement also underwent for measurement of frontal lobe function in two groups. RESULTS: There were no significant differences of FA in the DTI measures for either the schizophrenic patients compared with controls. FA was significantly decreased in women compared with men. Neuropsychological measurements such as Wisconsin card sorting test were correlated with FA of patients with schizophrenia. CONCLUSION: FA measures revealed no differences between schizophrenia and controls. The findings suggest that the structural integrity of white matter in patient with schizophrenia was not disrupted. The results are discussed in relation to previous studies reporting positive and negative findings. It is concluded that further studies using DTI in larger samples, improved and standardized methods of data acquisition and analysis are needed.

Development and Application of Cognitive Perceptual Assessment for Driving of People with Brain Injury - Comparison with Cognitive Behavioral Driver's Inventory

OBJECTIVE: We developed the Cognitive Perceptual Assessment for Driving (CPAD) to assess the driving ability of people with acquired brain injury. To find out the usefulness of this tool as a screening test for safe driving, we compared it with the Cognitive Behavioral Driver's Inventory (CBDI). METHOD: Subjects were 101 people with acquired brain injury who had driven a car before the injury. Each subject was evaluated with CPAD and CBDI. CPAD consisted of 8 tasks and 10 variables. We calculated CPAD score using 10 variables and compared CPAD with CBDI result and score. RESULTS: The average CPAD score was 49.65 7.97. According to CBDI test, the number of CBDI passing group was 36, borderline group was 27, and failing group was 38. CPAD variables and score showed significant correlation with CBDI score (p<0.05). There was significant difference in CPAD variables and score among the 3 groups (p<0.05). CONCLUSION: CPAD can be a useful tool for assessing the driving ability of the people with acquired brain injury.

Quantification of Brain Images Using Korean Standard Templates and Structural and Cytoarchitectonic Probabilistic Maps / 대한핵의학회잡지

PURPOSE: Population based structural and functional maps of the brain provide effective tools for the analysis and interpretation of complex and individually variable brain data. Brain MRI and PET standard templates and statistical probabilistic maps based on image data of Korean normal volunteers have been developed and probabilistic maps based on cytoarchitectonic data have been introduced. A quantification method using these data was developed for the objective assessment of regional intensity in the brain images. Materials and METHODS: Age, gender and ethnic specific anatomical and functional brain templates based on MR and PET images of Korean normal volunteers were developed. Korean structural probabilistic maps for 89 brain regions and cytoarchitectonic probabilistic maps for 13 Brodmann areas were transformed onto the standard templates. Brain FDG PET and SPGR MR images of normal volunteers were spatially normalized onto the template of each modality and gender. Regional uptake of radiotracers in PET and gray matter concentration in MR images were then quantified by averaging (or summing) regional intensities weighted using the probabilistic maps of brain regions. Regionally specific effects of aging on glucose metabolism in cingulate cortex were also examined. RESULTS: Quantification program could generate quantification results for single spatially normalized images per 20 seconds. Glucose metabolism change in cingulate gyrus was regionally specific: ratios of glucose metabolism in the rostral anterior cingulate vs. posterior cingulate and the caudal anterior cingulate vs. posterior cingulate were significantly decreased as the age increased. 'Rostral anterior'/ 'posterior' was decreased by 3.1% per decade of age (P< 10 (-11), r=0.81) and 'caudal anterior'/ 'posterior' was decreased by 1.7% (P< 10 (-8), r=0.72). CONCLUSION: Ethnic specific standard templates and probabilistic maps and quantification program developed in this study will be useful for the analysis of brain image of Korean people since the difference in shape of the hemispheres and the sulcal pattern of brain relative to age, gender, races, and diseases cannot be fully overcome by the nonlinear spatial normalization techniques.

Correlates of N-acetylaspartate and Cognitive Dysfunctions in Drug-naive Patients with Obsessive-compulsive Disorder: A Proton MRSI Study / 신경정신의학

OBJECTIVES: Reductions of N-acetylaspartate (NAA), a putative marker of neuronal viability, within the subcortical structures in patients with obsessive-compulsive disorder (OCD) are well documented. However, there has been no report of the NAA level in cortical structures. The authors used proton magnetic resonance spectroscopic imaging (1H-MRSI) to assess potential reductions of NAA in the frontal white matter, prefrontal gray matter, parietal gray and white matter, and the cingulate in drugnaive patients with OCD and explored the relationship between the brain metabolites and the degree to the dysfunction on the neuropsychological performances. METHODS : Thirteen drug-naive patients who met DSM-IV criteria for OCD and 13 healthy age-, sex-, handness- matched control subjects were studied. Subjects underwent MRI and 1H-MRSI and the peaks of NAA, creatine+phosphocreatine (Cr), and choline-containing compounds (Cho) were measured. Differences between patients and control subjects were tested for each metabolite ratio, and the relations between metabolite ratios and clinical symptoms, neuropsychological performances were examined. RESULTS : Upon comparison with normal controls, NAA/Cr ratio was significantly reduced in patients for the prefrontal gray matter, frontal white matter and anterior cingulate. There was no difference in Cho/Cr or NAA/Cho in any region. Also, a significant positive correlation was found between prefrontal NAA/Cr ratio and the delayed recall score of the Rey-Osterrieth Complex Figure Test in patients with OCD. CONCLUSION : The reduced NAA/Cr ratio in the prefrontal gray matter and frontal white matter suggests that OCD patients have lower neuronal viability than normal comparisons and it may be related to impaired organizational strategies in patients with OCD. These results support a role for the frontal-subcortical circuitry in a neurobiologic model of OCD.

A role of neuropsychological test in the patients with chronic liver disease / 대한내과학회지

BACKGROUND: Minimal (subclinical) hepatic encephalopathy (mHE) currently diagnosed by psychometric tests or neurophysiological test adversely affects daily functioning. In view of its sociomedical relevance, simple and reproducible tests for routine diagnosis are required. The aims of this study are to evaluate cognitive function of patients with chronic liver disease by computerized neuropsychological test (STIM), and the difference of cognitive function according to Child classification. METHODS: Between June, 2002 and February, 2003 We enrolled 61 randomized consecutive patients diagnosed with chronic liver disease by biochemical tests, ultrasonographic finding or histology. This study used finger tapping, visual CPT, spatial memory test, Wisconsin card sorting test chosen from Neuscan and STIM system (Neurosoft company, U.S.A) and global-local processing test. RESULTS: In the present study, significant correlation was found between neurologic abnormalities and the degree of liver disease. The result of neuropsychological test showed that cognitive function was decreased according to the severity of chronic liver disease, especially liver cirrhosis. Cirrhotic patients, especially Child C group, exhibited selective deficits in complex attentional and fine motor skills, visuospatial perception, with preservation of memory. CONCLUSION: The STIM in this study is simple, objective and reproducible method because it can subdivide evaluation of cognitive function and computerize the measurement of response. We assume that STIM may be used early detection method of mHE if the study will be in a large scale. Because psychomotor deficits found in mHE could have a disadvanting influence on daily functioning of patients, e.g., driving abilty of a car or performance at work, we concluded early detection of mHE and aggressive treatment of mHE in clinically asymptomatic cirrhotic patients is necessary for improvement of their quality of life.

Inspiratory and Expiratory Pulmonary CT: Change of Bronchial and Accompanying Pulmonary Arterial Diameter During Respiration in Healthy Adult Men

OBJECT: To evaluate changes in the diameter of bronchi and pulmonary arteries during respiration. MATERIALS AND METHODS: The ratio of the diameter of matched inner bronchi and accompanying pulmonary arteries was calculated from full inspiration and expiration HRCT of healthy men. RESULTS: In 106 pairs of matched bronchi and pulmonary arteries, the brohchial-arterial ratios were 0.61+/-0.18(upper lung), 0.72+/-0.21(lower lung), and0.65+/-0.20(total) at full inspiration and 0.51+/-0.32(upper lung), 0.52+/-0.15(lower lung), and 0.51+/-0.26(total) atfull expiration HRCT, denoting a statistically significant increase in bronchial diameter of the entire lung atfull inspiration. The inner diameter of the bronchus was larger than the diameter of the accompanying pulmonary artery by 0.1% at full expiration and 8.5% at full inspiration. CONCLUSION: The result of this study would be helpful in understanding the physiology of the lung during respiration.