Your search for: 'author:("Ye, Byoung Seok")' has returned 21 results. (0.032s) Save search

Authors: Park, Mincheol | Baik, Kyoungwon | Lee, Young-gun | Kang, Sung Woo | Jung, Jin Ho | Jeong, Seong Ho | Lee, Phil Hyu | Sohn, Young H. | Ye, Byoung Seok

Article Type: Correction

DOI: 10.3233/JAD-219020

Citation: Journal of Alzheimer's Disease, vol. 85, no. 2, pp. 941-941, 2022

Authors: Yoo, Han Soo | Lee, Sangwon | Jeong, Seong Ho | Ye, Byoung Seok | Sohn, Young H. | Yun, Mijin | Lee, Phil Hyu

Article Type: Research Article

Abstract: Background: Olfactory or autonomic dysfunction is one of the earliest prodromal symptoms of Parkinson’s disease (PD). It has not been investigated whether PD patients have different phenotypes depending on the presence of these prodromal symptoms. Objective: To investigate whether hyposmia-dominant and dysautonomia-dominant patients with early PD have different clinical manifestations and nigrostriatal degeneration. Methods: This cross-sectional study recruited 168 drug-naive PD patients and 34 control subjects. PD patients were classified as patients without hyposmia and dysautonomia (PD–H–D–, n  = 51), hyposmia-dominant patients (PD–H+D–, n  = 36), dysautonomia-dominant patients (PD–H–D+, n  = 33), and patients with hyposmia and dysautonomia (PD–H+D+, n  = 48). We then …compared the baseline clinical characteristics, striatal specific to non-specific binding ratio (SNBR), neuropsychological performance, and neuropsychiatric symptoms among the groups. Results: The PD–H+D–group had a lower SNBR in the ventral striatum (p  = 0.013), a greater asymmetric index of striatal SNBRs, and higher prevalence of apathy (p  = 0.021) than the PD–H–D+ group. The PD–H–D+ group had older age at onset (p  = 0.043) and a higher prevalence of REM sleep behavior disorder (p  = 0.041) than the PD–H+D–group. The PD–H+D+ group had higher motor deficits, lower cognitive function, and lower SNBRs in all striatal subregions than the PD–H–D–group. Decreased SNBRs in the anterior caudate, posterior caudate, and ventral striatum were associated with the presence of apathy. Conclusion: The present study suggests that hyposmia-dominant and dysautonomia-dominant PD have different clinical characteristics and patterns of striatal dopamine depletion. Show more

Keywords: Olfaction, hyposmia, autonomic function, dysautonomia, Parkinson’s disease

DOI: 10.3233/JPD-212747

Citation: Journal of Parkinson's Disease, vol. 11, no. 4, pp. 1703-1713, 2021

Authors: Chung, Seok Jong | Jeon, Seun | Yoo, Han Soo | Lee, Yang Hyun | Yun, Mijin | Lee, Seung-Koo | Lee, Phil Hyu | Sohn, Young Ho | Evans, Alan C. | Ye, Byoung Seok

Article Type: Research Article

Abstract: Background: Clinicopathological studies have demonstrated that the neuropsychological profiles and outcomes are different between two dementia subtypes, namely Alzheimer’s disease (AD) and Lewy bodies-related disease. Objective: We investigated the neural correlates of cognitive dysfunction in patients with AD-related cognitive impairment (ADCI) and those with Lewy bodies-related cognitive impairment (LBCI). Methods: We enrolled 216 ADCI patients, 183 LBCI patients, and 30 controls. Cortical thickness and diffusion tensor imaging analyses were performed to correlate gray matter and white matter (WM) abnormalities to cognitive composite scores for memory, visuospatial, and attention/executive domains in the ADCI spectrum (ADCI patients and controls) and the LBCI …spectrum (LBCI patients and controls) separately. Results: Memory dysfunction correlated with cortical thinning and increased mean diffusivity in the AD-prone regions, particularly the medial temporal region, in ADCI. Meanwhile, it only correlated with increased mean diffusivity in the WM adjacent to the anteromedial temporal, insula, and basal frontal cortices in LBCI. Visuospatial dysfunction correlated with cortical thinning in posterior brain regions in ADCI, while it correlated with decreased fractional anisotropy in the corpus callosum and widespread WM regions in LBCI. Attention/executive dysfunction correlated with cortical thinning and WM abnormalities in widespread brain regions in both disease spectra; however, ADCI had more prominent correlation with cortical thickness and LBCI did with fractional anisotropy values. Conclusions: Our study demonstrated that ADCI and LBCI have different neural correlates with respect to cognitive dysfunction. Cortical thinning had greater effects on cognitive dysfunction in the ADCI, while WM disruption did in the LBCI. Show more

Keywords: Alzheimer’s disease, cognition, Lewy body, neural correlate

DOI: 10.3233/JAD-190814

Citation: Journal of Alzheimer's Disease, vol. 73, no. 3, pp. 873-885, 2020

Authors: Park, Mincheol | Baik, Kyoungwon | Lee, Young-gun | Kang, Sung Woo | Jung, Jin Ho | Jeong, Seong Ho | Lee, Phil Hyu | Sohn, Young H. | Ye, Byoung Seok

Article Type: Research Article

Abstract: Background: Small vessel disease (SVD) magnetic resonance imaging (MRI) markers including deep and periventricular white matter hyperintensities (PWMH), lacunes, and microbleeds are frequently observed in Alzheimer’s disease (AD) and Lewy body disease (LBD), but their implication has not been clearly elucidated. Objective: To investigate the implication of SVD MRI markers in cognitively impaired patients with AD and/or LBD. Methods: We consecutively recruited 57 patients with pure AD-related cognitive impairment (ADCI), 49 with pure LBD-related cognitive impairment (LBCI), 45 with mixed ADCI/LBCI, and 34 controls. All participants underwent neuropsychological tests, brain MRI, and amyloid positron emission tomography. SVD MRI markers including …the severity of deep and PWMH and the number of lacunes and microbleeds were visually rated. The relationships among vascular risk factors, SVD MRI markers, ADCI, LBCI, and cognitive scores were investigated after controlling for appropriate covariates. Results: LBCI was associated with more severe PWMH, which was conversely associated with an increased risk of LBCI independently of vascular risk factors and ADCI. PWMH was associated with attention and visuospatial dysfunction independently of vascular risk factors, ADCI, and LBCI. Both ADCI and LBCI were associated with more lobar microbleeds, but not with deep microbleeds. Conclusion: Our findings suggest that PWMH could reflect degenerative process related with LBD, and both AD and LBD independently increase lobar microbleeds. Show more

Keywords: Alzheimer’s disease, Lewy body disease, mixed disease, periventricular white matter hyperintensity, small vessel disease, white matter hyperintensity

DOI: 10.3233/JAD-210669

Citation: Journal of Alzheimer's Disease, vol. 83, no. 2, pp. 545-556, 2021

Authors: Ye, Byoung Seok | Lee, Yoonju | Kwak, Kichang | Park, Yeong-Hun | Ham, Jee Hyun | Lee, Jae Jung | Shin, Na-Young | Lee, Jong-Min | Sohn, Young H. | Lee, Phil Hyu

Article Type: Research Article

Abstract: Background: Enlargement of the lateral ventricle is observed in dementia associated with Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). Objective: The degree of anteroposterior ventricular enlargement and its correlation with clinical and neuropsychological features were investigated in DLB patients. Methods: Forty-eight patients with DLB, 76 with AD, and 45 subjects with normal cognition (NC) underwent structural brain MRI and detailed neuropsychological tests. Ventricular shape was compared among the groups by visual inspection. Posterior ventricle enlargement (PVE) was defined as the ratio of the distance between the temporal and occipital horns of the lateral ventricle to the distance between …the temporal horn of the lateral ventricle and occipital pole of the brain. Results: After controlling for age, sex, and education, higher PVE was observed in the DLB group than in the AD group (68.5 ± 7.9% versus 62.8 ± 9.0%, respectively; p  = 0.001) or the NC group (61.9 ± 9.9%, p  = 0.002). However, higher PVE was not associated with poorer neuropsychological performance, nor was it associated with any clinical features in the DLB group after controlling for age, sex, and education. Conclusion: PVE occurs more often in DLB than in AD and NC. However, it is unclear how PVE is related to the clinical and neuropsychological features of DLB. Show more

Keywords: Alzheimer’s disease, dementia with Lewy bodies, ventricular enlargement

DOI: 10.3233/JAD-160062

Citation: Journal of Alzheimer's Disease, vol. 52, no. 4, pp. 1237-1243, 2016

Authors: Kim, Younggwang | Lee, Dongkyun | Cho, Kyoo Ho | Lee, Jae Jung | Ham, Jee Hyun | Ye, Byoung Seok | Lee, Seung-Koo | Lee, Jong-Min | Sohn, Young H. | Lee, Phil Hyu

Article Type: Research Article

Abstract: Background: Aging is the most important risk factor of development of dementia in Parkinson’s disease (PD), but there are no data on clinical and radiological heterogeneity of PD dementia (PDD) depending on age at onset. Objectives: The goal of this study was to examine whether patients with PDD are clinically and radiologically heterogeneous depending on age at onset. Methods: A total of 116 patients with PD dementia and 121 age- and sex-matched normal controls were enrolled. The subjects were divided into early-onset (EOPDD; n  = 39) and late-onset (LOPDD; n  = 77) PDD with the respective age-matched control group based on a …cutoff value of 70 years. The effects of diagnosis, age, and their interaction on neuropsychological tests, cortical thickness, and substantia innominata volume were assessed using analysis of covariance. Results: EOPDD patients had a poorer cognitive performance on digit backward, forward span test (p  = 0.011 and 0.05), and visual recognition memory function (p  = 0.012) compared with LOPDD patients. Additionally, EOPDD patients exhibited cortical thinning in the left anterior cingulate gyrus and the right inferior temporal gyrus, with significantly decreased normalized substantia innominata volume (p  = 0.044). Conclusions: Our data demonstrated that EOPDD patients exhibit poorer cognitive performance and more severe atrophy in the cortex and substantia innominata, implying that EOPDD may be a distinct phenotype different from LOPDD. Show more

Keywords: Age at onset, neuroanatomical correlates, neurocognitive performance, Parkinson’s disease dementia

DOI: 10.3233/JAD-160597

Citation: Journal of Alzheimer's Disease, vol. 55, no. 2, pp. 485-495, 2017

Authors: Jang, Hyemin | Ye, Byoung Seok | Woo, Sookyoung | Kim, Sun Woo | Chin, Juhee | Choi, Seong Hye | Jeong, Jee Hyang | Yoon, Soo Jin | Yoon, Bora | Park, Kyung Won | Hong, Yun Jeong | Kim, Hee Jin | Lockhart, Samuel N. | Na, Duk L. | Seo, Sang Won

Article Type: Correction

DOI: 10.3233/JAD-179010

Citation: Journal of Alzheimer's Disease, vol. 61, no. 2, pp. 825-825, 2018

Authors: Kim, Hee Jin | Im, Kiho | Kwon, Hunki | Lee, Jong Min | Ye, Byoung Seok | Kim, Yeo Jin | Cho, Hanna | Choe, Yearn Seong | Lee, Kyung Han | Kim, Sung Tae | Kim, Jae Seung | Lee, Jae Hong | Na, Duk L. | Seo, Sang Won

Article Type: Research Article

Abstract: There is growing evidence that the human brain is a large scale complex network. The structural network is reported to be disrupted in cognitively impaired patients. However, there have been few studies evaluating the effects of amyloid and small vessel disease (SVD) markers, the common causes of cognitive impairment, on structural networks. Thus, we evaluated the association between amyloid and SVD burdens and structural networks using diffusion tensor imaging (DTI). Furthermore, we determined if network parameters predict cognitive impairments. Graph theoretical analysis was applied to DTI data from 232 cognitively impaired patients with varying degrees of amyloid and SVD burdens. …All patients underwent Pittsburgh compound-B (PiB) PET to detect amyloid burden, MRI to detect markers of SVD, including the volume of white matter hyperintensities and the number of lacunes, and detailed neuropsychological testing. The whole-brain network was assessed by network parameters of integration (shortest path length, global efficiency) and segregation (clustering coefficient, transitivity, modularity). PiB retention ratio was not associated with any white matter network parameters. Greater white matter hyperintensity volumes or lacunae numbers were significantly associated with decreased network integration (increased shortest path length, decreased global efficiency) and increased network segregation (increased clustering coefficient, increased transitivity, increased modularity). Decreased network integration or increased network segregation were associated with poor performances in attention, language, visuospatial, memory, and frontal-executive functions. Our results suggest that SVD alters white matter network integration and segregation, which further predicts cognitive dysfunction. Show more

Keywords: Amyloid, diffusion tensor imaging, graph theory, small vessel disease, white matter network

DOI: 10.3233/JAD-141623

Citation: Journal of Alzheimer's Disease, vol. 44, no. 3, pp. 963-975, 2015

Authors: Ye, Byoung Seok | Choi, Seong Hye | Han, Seol-Heui | Kim, SangYun | Yang, Dong-Won | Park, Kee Hyung | Han, Hyun Jeong | Youn, Young Chul | Choi, Byung-Ok | Kim, Seung H. | Woo, Sook-young | Na, Duk L. | Kim, Eun-Joo

Article Type: Research Article

Abstract: Background: Cognitive performance changes with chronological aging. Previous studies investigating clinical heterogeneity in frontotemporal dementia (FTD) according to the age of symptom onset did not consider the effect of chronological aging on cognition. Objective: We compared cognitive and behavioral symptoms in patients with early-onset (EO) and late-onset (LO) FTD with consideration of chronological aging effect. Methods: A total of 166 FTD patients were enrolled consecutively from multi-center memory clinics using a nationwide FTD register. To control for the effects of chronological aging on neuropsychological scores, seven hundred and two subjects with normal cognition were also enrolled and regression models were …set up. Neuropsychological scores that were detrended with the regression models and the behavioral symptoms of the EO-FTD and LO-FTD groups were compared. Subgroup analyses were performed for three main subtypes of FTD, behavioral variant frontotemporal dementia (bvFTD), semantic dementia (SD), and progressive non-fluent aphasia (PNFA). Results: Among 166 FTD patients, there were 76 bvFTD, 57 SD, and 33 PNFA patients who met new diagnostic criteria for bvFTD or primary progressive aphasia, respectively. LO-FTD (48.2%) was more common than previously thought and the proportions of EO and LO groups differed across FTD subtypes. EO-FTD patients had lower memory and frontal/executive scores and more prominent frontal/behavioral symptoms than LO-FTD patients. Conclusion: Our study suggested that FTD could be heterogeneous with respect the age of symptom onset. After controlling for the effects of chronological aging, EO-FTD patients exhibited more profound memory and frontal/executive dysfunction and more behavioral symptoms than LO-FTD patients. Show more

Keywords: Age at symptom onset, behavior, frontotemporal dementia, neuropsychology

DOI: 10.3233/JAD-141044

Citation: Journal of Alzheimer's Disease, vol. 45, no. 2, pp. 599-608, 2015

Authors: Lee, Yang Hyun | Jeon, Seun | Yoo, Han Soo | Chung, Seok Jong | Jung, Jin Ho | Baik, Kyoungwon | Sohn, Young H. | Lee, Phil Hyu | Yun, Mijin | Evans, Alan C. | Ye, Byoung Seok

Article Type: Research Article

Abstract: Background: The relationship among amyloid-β (Aβ) deposition on amyloid positron emission tomography (PET), cortical metabolism on 18 F-fluoro-2-deoxy-D-glucose (FDG)-PET, and clinical diagnosis has not been elucidated for both Alzheimer’s disease (AD) and Lewy body disease (LBD). Objective: We investigated the patterns of cerebral metabolism according to the presence of AD and LBD. Methods: A total of 178 subjects were enrolled including 42 pure AD, 32 pure LBD, 34 Lewy body variant AD (LBVAD), 15 LBD with amyloid, 26 AD with dementia with Lewy bodies (DLB), and 29 control subjects. Pure AD, LBVAD, and AD with DLB groups had biomarker-supported diagnoses …of typical AD, while pure LBD, LBD with amyloid, and AD with DLB groups had biomarker-supported diagnoses of typical LBD. Typical AD and LBD with amyloid showed amyloid-positivity on 18 F-florbetaben (FBB) PET, while typical LBD and LBVAD had abnormalities on dopamine transporter PET. We measured regional patterns of glucose metabolism using FDG-PET and evaluated their relationship with AD and LBD. Results: Compared with control group, typical AD and typical LBD commonly exhibited hypometabolism in the bilateral temporo-parietal junction, precuneus, and posterior cingulate cortex. Typical AD showed an additional hypometabolism in the entorhinal cortex, while patients with dopamine transporter abnormality-supported diagnosis of LBD showed diffuse hypometabolism that spared the sensory-motor cortex. Although the diffuse hypometabolism in LBD also involved the occipital cortex, prominent occipital hypometabolism was only seen in LBD with amyloid group. Conclusion: Combining clinical and metabolic evaluations may enhance the diagnostic accuracy of AD, LBD, and mixed disease cases. Show more

Keywords: Alzheimer’s disease, amyloid, glucose metabolism, lewy body disease

DOI: 10.3233/JAD-201094

Citation: Journal of Alzheimer's Disease, vol. 79, no. 4, pp. 1471-1487, 2021