Purpose: The survival of organisms critically depends on avoidance responses to lifethreatening stimuli. Information about dangerous situations needs to be remembered to produce defensive behavior. To investigate underlying brain regions to process information of danger, manganese-enhanced MRI (MEMRI) was used in olfactory fear-conditioned rats. Materials and Methods: Fear conditioning was conducted in male Sprague-Dawley rats. The animals received nasal injections of manganese chloride solution to monitor brain activation for olfactory information processing. Twenty-four hours after manganese injection, rats were exposed to electric foot shocks with odor cue for one hour. Control rats were exposed to the same odor cue without foot shocks. Fortyeight hours after the conditioning, rats were anesthetized and their brains were scanned with 9.4T MRI. Acquired images were processed and statistical analyses were performed using AFNI. Results: Manganese injection enhanced brain areas involved in olfactory information pathways in T1 weighted images. Rats that received foot shocks showed higher brain activation in the central nucleus of the amygdala, septum, primary motor cortex, and preoptic area. In contrast, control rats displayed greater signals in the orbital cortex and nucleus accumbens. Conclusion Nasal delivery of manganese solution enhanced olfactory signal pathways in rats. Odor cue paired with foot shocks activated amygdala, the central brain region in fear, and related brain circuits. Use of MEMRI in fear conditioning provides a reliable monitoring technique of brain activation for fear learning.

Objectives: Maltreatment experiences can alter brain function related to emotion regulation, such as cognitive reappraisal. While dysregulation of emotion is an important risk factor to mental health problems in maltreated people, studies reported alterations in brain networks related to cognitive reappraisal are still lacking. Methods: Twenty-seven healthy subjects were recruited in this study. The maltreatment experiences and positive reappraisal abilities were measured using the Childhood Trauma Questionnaire-Short Form and the Cognitive Emotion Regulation Questionnaire, respectively. Twelve subjects reported one or more moderate maltreatment experiences. Subjects were re-exposed to pictures after the cognitive reappraisal task using the International Affective Picture System during fMRI scan. Results: The maltreatment group reported more negative feelings on negative pictures which tried cognitive reappraisal than the no-maltreatment group (p < 0.05). Activities in the right superior marginal gyrus and right middle temporal gyrus were higher in the maltreatment group (uncorrected p < 0.001, cluster size > 20). Conclusions We found that paradoxical activities in semantic networks were shown in the victims of maltreatment. Further study might be needed to clarify these aberrant functions in semantic networks related to maltreatment experiences.

PURPOSE: This study was to present the functional brain mapping of both functional magnetic resonance imaging(MRI) and transcranial magnetic stimulation(TMS) in a case of schizencephaly. MATERIALS AND METHODS: A 28-year-old man, who had left hemiplegia and schizencephaly in right cerebral hemisphere, was examed with both functional MRI and TMS. Motor function of left hand was decreased whereas right hand was within normal limit. For functional MRI, gradient-echo echo planar imaging(TR/TE/alpha=1.2 sec/90 msec/90) was employed. The paradigm of motor task consisted of repetitive self-pased hand flexion-extension exercises with 1-2 Hz periods. An image set of 10 slices was repetitively acquired with 15 seconds alternating periods of task performance and rest and total 6 cycles( three ON periods and three OFF periods) were performed. In brain mapping, TMS was performed with the round magnetic stimulator(mean diameter; 90mm). The magnetic stimulation was done with 80% of maximal output. The latency and amplitude of motor evoked potential(MEP)s were obtained from both abductor pollicis brevis(APB) muscles. RESULTS: Functional MRI revealed activation of the left primary motor cortex with flexion-extension exercises of healthy right hand. On the other hand, the left primary motor cortex, left supplementary motor cortex, and left premotor areas were activated with flexion-extension exercises of left hand. In TMS, magnetic evoked potentials were induced in no areas of right cerebral hemisphere, but in 5 areas of left cerebral hemisphere from both abductor pollicis brevis. Latency, amplitude, and contour of response of the magnetic evoked potentials in both hands were similar. CONCLUSION: Functional MRI and TMS in a patient with schizencephaly were successfully used to localize cortical motor function. Ipsilateral motor pathway is thought to be secondary to reinforcement of the corticospinal tract of the ipsilateral motor cortex.
Adult ; Brain Mapping ; Cerebrum ; Evoked Potentials ; Exercise ; Hand ; Hemiplegia ; Humans ; Magnetic Resonance Imaging ; Malformations of Cortical Development* ; Motor Cortex ; Muscles ; Neuronal Plasticity ; Pyramidal Tracts ; Task Performance and Analysis ; Transcranial Magnetic Stimulation*

BACKGROUND: A deletion (D)/insertion (I) polymorphism of the angiotensin-converting enzyme (ACE) gene is known to be associated with hypertension, left ventricular hypertrophy, myocardial infarction. Cardiac diseases, such as atrial fibrillation, valvular heart disease, myocardiac infarction and coronary artery disease have been clearly associated with increasing the risk of ischemic stroke. We investigated the relationship between ACE gene deletion/insertion (D/I) polymorphism and the pattern of ischemic stroke. METHODS: The pattern of ACE genotypes in 59 stroke patients including symptomatic carotid artery territory cerebral ischemia were compared with 101 age-matched control subjects. In the stroke patients, the degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded according to duplex neck sonography and magnetic resonance angiography. DNA was extracted from peripheral blood and ACE I/D polymorphism is confirmed by PCR method. RESULTS: In the stroke patients, 25.4% showed the I I genotypes, 8.5% the ID genotypes and 66.1% the DD genotypes. In the control group, the frequencies of each genotype were 20.8%, 55.4% and 23.8%, respectively. The DD genotypes were more common in patients with ischemic stroke compared with the controls, but there was no significant association between ACE genotypes and sub-types of cerebrovascular disease. CONCLUSIONS: The deletion polymorphism in the angiotensin-converting enzyme gene may play a role in development of ischemic stroke.
Angiotensins* ; Atrial Fibrillation ; Brain Ischemia ; Carotid Arteries ; Cerebral Infarction ; Constriction, Pathologic ; Coronary Artery Disease ; DNA ; Genotype ; Heart Diseases ; Heart Valve Diseases ; Humans ; Hypertension ; Hypertrophy, Left Ventricular ; Infarction ; Magnetic Resonance Angiography ; Myocardial Infarction ; Neck ; Peptidyl-Dipeptidase A* ; Polymerase Chain Reaction ; Stroke*

PURPOSE: The aim of this study is to determine possibility of application of in vivo proton (1H) magnetic resonance spectroscopy (MRS) in distinguishing cystic mass arising around pancreas by comparison of in vivo MRS, in vitro MRS using 3T MR machine, based on nuclear magnetic resonance (NMR). MATERIALS AND METHODS: We obtained spectra of in vivo MRS, in vitro MRS and NMR from abdominal mass arising around pancreas (mucinous cystic neoplasm=5, intraductal papillary mucin producing tumor=5, pseudocyst=1, and lymphangioma=1). We estimated existence of peak of in vivo MRS, and in vitro MRS concordant to that of NMR. We also evaluated differential peak for predicting specific disease. RESULTS: Correlation of presence of peak with NMR showed showed sensitivity of 29.6%, specificity of 82.6% and accuracy of 67.7% on in vivo MRS (p = 0.096, McNemar test), sensitivity of 57.1% and specificity of 92.6% and accuracy of 82.3% on in vitro MRS (p = 0.362, McNemar test). The spectra of NMR for IPMT showed more frequent peaks at 3.5-4.0 ppm (p=0.026). CONCLUSION: Although chemical analysis, using NMR could be regarded as possible tool to differentiate cystic masses, in vivo and in vitro MRS need further technical evolution for clinical application.
Magnetic Resonance Spectroscopy ; Mucins ; Pancreas ; Protons ; Sensitivity and Specificity ; Spectrum Analysis

OBJECTIVES: To evaluate retrospectively, the possible difference in diffusion tensor imaging (DTI) metric of fractional anisotropy (FA) between good and poor surgical outcome cochlear implantation (CI) patients using investigator-independent voxel-wise analysis. METHODS: Eighteen patients (11 males, 7 females; mean age, 5.9 years) with profound sensorineural hearing loss underwent DTI scans using a 3.0 Tesla magnetic resonance scanner. Among the 18 patients, 10 patients with categories of auditory performance (CAP) score over 6 were classified into the good outcome group and 8 patients with CAP score below 6 were classified into the poor outcome group. The diffusion tensor scalar measure was calculated from the eigenvalues of the tensor on a voxel-by-voxel basis from each subject and two-sample t-test evaluation between good and poor outcome subjects were performed for each voxel of FA values, across the entire brain, with a voxel-wise intensity threshold of P<0.0005 (uncorrected) and a contiguous cluster size of 64 voxels. Individual values of FA were measured by using the region-of-interest based analysis for correlation analysis with CAP scores, open sentence and open word scores. RESULTS: Two-sample t-test evaluation using SPM voxel-wise analysis found significantly higher FA values at the several brain areas including Broca's area, genu of the corpus callosum, and auditory tract in good outcome subjects compared to poor outcome subjects. Correlation analyses between FA and CAP scores, open sentence and open word scores revealed strong correlations at medial geniculate nucleus, Broca's area, genu of the corpus callosum and auditory tract. CONCLUSION: Investigator-independent voxel-based analysis of DTI image demonstrated that good outcome subjects showed better neural integrity at brain areas associated with language and auditory functions, suggesting that the conservation of microstructural integrity of these brain areas is important. Preoperative functional imaging may be helpful for CI.
Anisotropy ; Brain ; Cochlear Implantation ; Cochlear Implants ; Corpus Callosum ; Diffusion ; Diffusion Tensor Imaging ; Hearing Loss ; Hearing Loss, Sensorineural ; Humans ; Magnetic Resonance Spectroscopy ; Male ; Retrospective Studies

Objective: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients. Methods: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition. Results: Engagement of additional frontoparietal networks with poorer performance of WCST was found during the fMRI scan in OCD patients. Selected regions of interest from activated regions have positive relationships with dysfunctional beliefs and with the unacceptable thoughts symptom dimension in the OCD group. Conclusion Findings suggest that alteration in frontoparietal networks related to cognitive deficits can be associated with dysfunctional beliefs while performing conventional neurocognitive tasks and this association with dysfunctional beliefs may be pronounced in the unacceptable thoughts domain-dominant OCD patients.

Objective: Thought-action fusion (TAF), one of the most-studied dysfunctional beliefs in obsessive-compulsive disorder, represents an individual’s belief that his/her thoughts directly influence events. TAF belief types are divided into personal thoughts relating to positive (positive TAF) and negative outcomes (negative TAF). However, the neural mechanisms underlying both aspects of the TAF response remain elusive. Methods: This functional magnetic resonance imaging study aimed to investigate the neural circuits related to positive and negative TAF and their relationships with psychological measures. Thirty-one healthy male volunteers participated in a modified TAF task wherein they were asked to read the name of a close person embedded in positive statements (PS) or negative statements (NS). Results: Conjunction analysis revealed activation of the fusiform and lingual gyri, midcingulate and superior medial frontal gyri, inferior orbitofrontal gyrus, and temporoparietal junction. The NS ＞ PS comparison showed additional activation in the precuneus and medial prefrontal cortex, superior frontal gyrus, insula, globus pallidus, thalamus, and midbrain. Precuneus activity was associated with the TAF score among these areas. Moreover, activity in the inferior orbitofrontal gyrus, insula, superior, middle and medial frontal gyri, globus pallidus, inferior parietal lobule, and precuneus was associated with dimensional obsessive-compulsive scores. In contrast, the PS ＞ NS comparison revealed no significant activation. Conclusion These results suggest that negative TAF, relative to positive TAF, recruits additional regions for self-referential processing, salience, and habitual responding, which may contribute to the activation of the belief that a negative thought increases the probability of that negative outcome.

Objective: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients. Methods: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition. Results: Engagement of additional frontoparietal networks with poorer performance of WCST was found during the fMRI scan in OCD patients. Selected regions of interest from activated regions have positive relationships with dysfunctional beliefs and with the unacceptable thoughts symptom dimension in the OCD group. Conclusion Findings suggest that alteration in frontoparietal networks related to cognitive deficits can be associated with dysfunctional beliefs while performing conventional neurocognitive tasks and this association with dysfunctional beliefs may be pronounced in the unacceptable thoughts domain-dominant OCD patients.

In February 2018, the Withdrawal of the Life-sustaining Treatment (WLST) Decision Act was legalized in Korea. Donation after circulatory death (DCD) after WLST was classified as DCD category III. We report the first case of successful organ donation after WLST in Korea. A 52-year-old male who experienced cerebral hemorrhage was a potential brain-dead donor with donation consent. During the first brain death examination, Babinski reflex was present, which disappeared two days later. Then, electroencephalography was performed five times at intervals of 2 to 3 days, according to the recommendation of a neurologist.The patient was transferred to the OR at 19:30 July 3, 2020. At 20:00, an intensive care unit specialist performed extubation and discontinued vasopressors. Oxygen saturation fell to < 70% in 1 minute, which signaled the beginning of functional warm ischemia. At 20:15, asystole was confirmed; after 5 minutes of “no-touch time,” circulatory death was declared.Organ procurement surgery was initiated, with surgeons performing the recipient surgery ready in the adjacent OR. Through the first successful DCD case, we expected that DCD will be actively implemented in Korea, saving the lives of patient waiting for transplantation and resolving the imbalance between organ receipt and donation.