Over the past decade, an increasing number of neuroimaging studies have provided insight into the neurobiological mechanisms of posttraumatic stress disorder (PSTD). In particular, molecular neuroimaging techniques have been employed in examining metabolic and neurochemical processes in PTSD. This article reviews molecular neuroimaging studies in PTSD and focuses on findings using three imaging modalities including positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance spectroscopy (MRS). Although there were some inconsistences in the findings, patients with PTSD showed altered cerebral metabolism and perfusion, receptor bindings, and metabolite profiles in the limbic regions, medial prefrontal cortex, and temporal cortex. Studies that have investigated brain correlates of treatment response are also reviewed. Lastly, the limitations of the molecular neuroimaging studies and potential future research directions are discussed.
Brain ; Humans ; Magnetic Resonance Spectroscopy ; Metabolism ; Neuroimaging* ; Perfusion ; Positron-Emission Tomography ; Prefrontal Cortex ; Stress Disorders, Post-Traumatic* ; Temporal Lobe ; Tomography, Emission-Computed, Single-Photon

BACKGROUNDS/AIMS: While clinical practice guidelines are effective tools for improving the quality of patient care and provide specific recommendations for daily practice, the usage of them have been often suboptimal. Therefore, evaluation of physician attitude to guidelines is an important initial step in improving guideline adherence levels. The aim of this study was to survey the attitude on general guidelines and adherence with the Korea Practical Guidelines for gallbladder (GB) polyp two year after their publication and distribution among Korean private clinicians. METHODS: To evaluate the survey, questionnaires were sent with a stamp on an addressed envelope to 3,256 private clinicians who were registered at the Seoul Medical Association in April, 2010. From the 3,256 questionnaires, 376 clinicians (11.5%) responded to the survey. RESULTS: A total of 91.0% responders agreed to the statement that general guidelines were useful tools for improving patient care and quality of care. One hundred one responders (26.9%) stated that they were aware of the Korea GB polyp guidelines while 73 physicians (72.3%) founded the guideline had changed their practice and user-friendly. Most of physicians (73.4%) agreed to practical procedures recommended by guidelines. CONCLUSIONS: Korean primary physicians were generally positive to the practical guidelines, as propagation of the guideline among primary physicians may improve adherence to guideline and patients care for GB polyps.
Gallbladder* ; Guideline Adherence ; Humans ; Korea ; Patient Care ; Polyps* ; Publications ; Seoul ; Surveys and Questionnaires

Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disease characterized by persistent dizziness, unsteadiness, and/or non-spinning vertigo, and is the most common vestibular syndrome in young adults. A stiffened postural control strategy, shift to reliance on visual over vestibular information, and hypervigilance to the environment have been suggested as possible pathophysiological mechanisms of PPPD. However, the exact mechanisms remain unclear. Recently, neuroimaging studies using magnetic resonance imaging and single photon emission computed tomography have provided pivotal insights into the pathophysiology of PPPD. The aim of this review was to evaluate and summarize the existing data on neuroimaging studies in PPPD. In summary, these studies fairly consistently reported decreased brain structure, function, and connectivity among the areas involved in multisensory vestibular processing and spatial cognition, and increased function and connectivity in the visual processing areas in patients with PPPD. The detected brain changes might reflect maladaptive and compensatory mechanisms including dysfunctional integration of multisensory vestibular information and visual dependence. Notably, various factors including personality traits (i.e., neuroticism), psychiatric comorbidities (i.e., anxiety and depression), and triggering factors (i.e., peripheral vestibular lesions) seem to modulate brain functional activity and connectivity patterns, possibly accounting for some differences across the results. Future studies should carefully control for these confounding effects in order to draw firm conclusions.

The sibling relationship and its potential impact on neurodevelopment and mental health are important areas of neuroscientific research. Validation of the tools assessing the quality of the sibling relationship would be the first essential step for conducting neurobiological and psychosocial studies related to the sibling relationship. However, to the best of our knowledge, no sibling relationship assessment tools have been empirically validated in Korean. We aimed to evaluate the psychometric properties of the Korean version of the Lifespan Sibling Relationship Scale (LSRS), which is one of the most commonly used self-report questionnaires to assess the quality of the sibling relationship. A total of 109 adults completed a series of self-report questionnaires including the LSRS, the mental health subscale of the Medical Outcomes Study-Short Form 36 version 2 (SF36v2), the Satisfaction with Life Scale (SLS), and the Marlowe-Crowne Social Desirability Scale (MC-SDS). The internal consistency, subscale intercorrelations, one-week test-retest reliability, convergent validity, divergent validity, and the construct validity were assessed. All six subscale scores and the total score of the LSRS demonstrated good internal consistency (Cronbach's alpha=0.85-0.94) and good test-retest reliability (intraclass correlation coefficient=0.77-0.92). Correlations of the LSRS with the SF36v2 mental health score (r=0.32, p=0.01) and with the SLS (r=0.27, p=0.04) supported the good convergent validity. The divergent validity was shown by the non-significant correlation of the LSRS with the MC-SDS (r=0.15, p=0.26). Two factors were extracted through factor analysis, which explained 78.63% of the total variance. The three Adult subscales loaded on the first factor and the three Child subscales loaded on the second factor. Results suggest that the Korean version of the LSRS is a reliable and valid tool for examining the sibling relationship.
Adult ; Child ; Humans ; Mental Health ; Psychometrics ; Reproducibility of Results* ; Siblings* ; Social Desirability ; Surveys and Questionnaires

BACKGROUND AND PURPOSE: Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). METHODS: A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups. RESULTS: The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group. CONCLUSIONS: The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.
Alzheimer Disease* ; Brain* ; Cerebrovascular Circulation ; Cognition ; Cross-Sectional Studies ; Dementia ; Frontal Lobe ; Humans ; Occipital Lobe ; Parietal Lobe ; Perfusion* ; Prefrontal Cortex ; Rabeprazole ; Temporal Lobe ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon

BACKGROUND AND PURPOSE: Nicergoline is an ergoline derivative that is used to treat cognitive deficits in cerebrovascular disease and various forms of dementia. Although therapeutic effects of nicergoline have been established, little is known about its effects on cerebral perfusion in Alzheimer's disease (AD). The aim of this study was to examine the role of nicergoline in regional cerebral blood flow (rCBF) of AD patients using technetium-99m hexa-methyl-propylene-amine-oxime single photon emission computed tomography (SPECT). METHODS: Sixteen patients with early AD underwent a comprehensive clinical assessment including cognitive testing and SPECT scans before and after nicergoline treatment. Nicergoline (30 mg twice daily) was administered for an average duration of 1.5 years. Clinical and cognitive functioning was assessed using the Mini-Mental State Examination, Clinical Dementia Rating (CDR), CDR-Sum of Boxes, Global Deterioration Scale, Barthel Activities of Daily Living Index, Instrumental Activities of Daily Living, and Geriatric Depression Scale. RESULTS: Nicergoline treatment induced changes in the severity of dementia, cognitive function, activities of daily living, and depressive symptoms, which were not statistically significant. During the follow-up, the patients showed significant increases in their relative rCBF in the superior frontal gyrus, precentral gyrus, and postcentral gyrus. CONCLUSIONS: Nicergoline treatment improves perfusion of the frontal and parietal regions in early AD patients. It is possible that the increased perfusion in the superior frontal gyrus may be related to the mechanisms that delay or prevent progressive deterioration of cognitive functions in AD.
Activities of Daily Living ; Alzheimer Disease* ; Cerebrovascular Circulation ; Cerebrovascular Disorders ; Cognition ; Cognition Disorders ; Dementia ; Depression ; Ergolines ; Follow-Up Studies ; Frontal Lobe ; Humans ; Nicergoline* ; Parietal Lobe ; Perfusion* ; Pilot Projects* ; Prefrontal Cortex ; Somatosensory Cortex ; Therapeutic Uses ; Tomography, Emission-Computed, Single-Photon

Purpose: Increasing attention has been paid to low-intensity transcranial focused ultrasound (tFUS) for its potential therapeutic effects in Alzheimer's disease (AD). While preclinical studies have shown promising therapeutic effects of low-intensity tFUS in AD models, its efficacy and safety remain unclear in humans. In this pilot study, we investigated the effects of low-intensity tFUS on blood-brain barrier opening, the regional cerebral metabolic rate of glucose (rCMRglu), and cognition in patients with AD. Methods: After receiving institutional review board approval, four patients with AD received tFUS to the hippocampus immediately after an intravenous injection of a microbubble ultrasound contrast agent. Sonication was delivered at low-intensity, at a pressure level below the threshold for blood-brain barrier opening. Patients underwent brain magnetic resonance imaging, 18F-fluoro-2-deoxyglucose positron emission tomography, and neuropsychological assessments before and after the tFUS procedure. A whole-brain voxel-wise paired t test was conducted to compare rCMRglu before and after tFUS. Results: The sonication, as anticipated, did not show evidence of active blood-brain barrier opening on T1 dynamic contrast-enhanced magnetic resonance imaging. rCMRglu in the superior frontal gyrus (P<0.001), middle cingulate gyrus (P<0.001), and fusiform gyrus increased after tFUS (P=0.001). Patients demonstrated mild improvement in measures of memory, executive, and global cognitive function following tFUS. No adverse events were reported. Conclusion These results suggest that hippocampal sonication with low-intensity tFUS may have beneficial effects on cerebral glucose metabolism and cognitive function in patients with AD. Further larger studies are needed to confirm the therapeutic efficacy of tFUS in AD.

Background: A pooling test is a useful tool for mass screening of coronavirus disease 2019 (COVID-19) in the pandemic era. We aimed to optimize a simple two-step pooling test by estimating the optimal pool size using experimental and mathematical validation. Materials and Methods: Experimental pools were created by mixing one positive respiratory sample with various numbers of negative samples. We selected positive samples with cycle threshold (Ct) values greater than 32 to validate the efficiency of the pooling test assuming a high likelihood of false-negative results due to low viral loads. The positivities of the experimental pools were investigated with a single reverse-transcription polymerase chain reaction (RT-PCR) using the U-TOP™ COVID-19 Detection Kit Plus (Seasun Biomaterials, Daejeon, Korea). We used the Dorfman equation to calculate the optimal size of a pooling test mathematically. Results: Viral RNA could be detected in a pool with a size up to 11, even if the Ct value of a positive sample was about 35. The Dorfman equation showed that the optimal number of samples in a pool was 11 when the prevalence was assumed to be 0.66% based on the test positivity in Daejeon, Korea from April 1, 2020 to November 10, 2020. The efficiency of the pooling test was 6.2, which can save 83.9 of 100 individual tests. Conclusion Eleven samples in a pool were validated optimal experimentally assuming a prevalence of 0.66%. The pool size needs modification as the pandemic progresses; thus, the prevalence should be carefully estimated before pooling tests are conducted.

Background: A pooling test is a useful tool for mass screening of coronavirus disease 2019 (COVID-19) in the pandemic era. We aimed to optimize a simple two-step pooling test by estimating the optimal pool size using experimental and mathematical validation. Materials and Methods: Experimental pools were created by mixing one positive respiratory sample with various numbers of negative samples. We selected positive samples with cycle threshold (Ct) values greater than 32 to validate the efficiency of the pooling test assuming a high likelihood of false-negative results due to low viral loads. The positivities of the experimental pools were investigated with a single reverse-transcription polymerase chain reaction (RT-PCR) using the U-TOP™ COVID-19 Detection Kit Plus (Seasun Biomaterials, Daejeon, Korea). We used the Dorfman equation to calculate the optimal size of a pooling test mathematically. Results: Viral RNA could be detected in a pool with a size up to 11, even if the Ct value of a positive sample was about 35. The Dorfman equation showed that the optimal number of samples in a pool was 11 when the prevalence was assumed to be 0.66% based on the test positivity in Daejeon, Korea from April 1, 2020 to November 10, 2020. The efficiency of the pooling test was 6.2, which can save 83.9 of 100 individual tests. Conclusion Eleven samples in a pool were validated optimal experimentally assuming a prevalence of 0.66%. The pool size needs modification as the pandemic progresses; thus, the prevalence should be carefully estimated before pooling tests are conducted.

As the outbreak of coronavirus disease 2019 continues and the number of confirmed cases requiring isolation increases, there is a need for a safe and efficient system to assess patients' condition. We developed and evaluated a self-assessment questionnaire consisting of 23 symptoms with linear-scale scores from 0 to 10. Patients were asked to indicate their worst score for each symptom daily, and medical personnel assessed clinical improvement or deterioration based on the changes in scores. Focused communication on severity of specific symptoms was the primary advantage for the clinicians, and a thorough check for their symptoms was helpful for patients.