Biomedical subjects

Yong Tae Kwak

Publications and source records attributed to Yong Tae Kwak.

3 recordsLinked to original sources

PubMed2006

Quantitative EEG findings in different stages of Alzheimer's disease.

Although quantitative EEG (q-EEG) has been used in Alzheimer's disease (AD), q-EEG changes in AD are complex because of the progressive nature of this disease. The topographical spectral power and occipital peak frequency (OPF) were compared among elderly controls, patients with mild cognitive impairment (MCI), and patients with four stages of AD. In AD patients, except those with a Clinical Dementia Rating Scale (CDR) score of 0.5, OPF was lower than that of elderly controls. Compared with elderly controls, the left anterior alpha spectral power was reduced in CDR 0.5; both posterior theta spectral powers were increased and all alpha spectral powers were reduced in CDR 1; all alpha and beta spectral powers were reduced and theta spectral power was increased in CDR 2; and all alpha and beta spectral powers were reduced and all delta and theta spectral powers were increased in CDR 3. Patients with MCI exhibited a reduction in both centrotemporal, posterior delta and left anterior, centrotemporal theta fields. The Mini-Mental State Examination (MMSE) score was related to left OPF, right posterior delta and left anterior theta spectral power, in that order. This study suggests that q-EEG in MCI shows nonoverlapping features between controls and AD patients, and AD patients show dynamic changes as the disease progresses. Finally, the left OPF is the parameter most significantly correlated with MMSE score.

Aged↗

PubMed2004

"Closing-in" phenomenon in Alzheimer's disease and subcortical vascular dementia.

BACKGROUND: The 'closing-in' phenomenon is defined as a tendency to close in on a model while copying it. This is one of several constructional apraxia observed in dementia, particularly in Alzheimer's disease (AD). The aim of this study was to investigate the usefulness of it in the differential diagnosis of AD and subcortical vascular dementia (SVD) and to clarify the factors associated with it. METHODS: We operationally defined and classified it into three types, namely overlap, adherent, and near type. We analyzed the incidence of it in patients with AD (n = 98) and SVD (n = 48). RESULTS: AD patients exhibited a significantly higher occurrence of it as compared to SVD patients. Among the different types of it, the overlap and adherent types occurred almost exclusively in AD patients. A discriminant analysis in AD subjects revealed that the scores obtained from the MMSE, CDR, Barthel index, and the Rey-Osterrieth complex figure test were correlated significantly with the occurrence of it. There was no statistical difference between the Q-EEG parameters of patients that exhibited the closing-in phenomenon and those that did not. CONCLUSIONS: This study suggests that the closing-in phenomenon is phase- and AD-specific and might be a useful tool for the differential diagnosis of AD and SVD.

Adult↗

PubMed2003

Important link between dementia subtype and apolipoprotein E: a meta-analysis.

To evaluate the differential diagnostic role of apolipoprotein E (apoE) genotype in dementia, we carried out a meta- analysis of 78 case-control series, including our own new data. The dementia subjects were grouped into Alzheimer's disease (AD) and non-AD. AD patients were subgrouped according to their subtypes, and non-AD patients into vascular dementia (VD), mixed dementia (MD), and non-AD non-VD dementia (NAVD). The apoE allele frequencies and apoE genotype-specific odds ratio (OR) of each group were estimated. The (4 allele frequency was higher in all of the dementia subgroups than in the elderly controls, and the associations with (4 allele were lower in the non-AD (OR 1.8) patients than in the AD (OR 4.2) patients. However, the apoE-related risk alsovaried as a function of the subgroup, in both the AD and non-AD groups; for AD, it was dependent on the subtype of AD (OR 2.3 - 11.3), and higher in late- onset and familial cases than in early-onset and sporadic cases, respectively; among non-AD patients, it was higher in MD (OR 2.6) than in VD (OR 1.3), and intermediate in NAVD (OR 1.9), in which a significant difference was also found between Lewy body dementia (LBD) type (OR 5.1) and non-LBD type (OR 1.3). In conclusion, variability in the apoE-related risk was found in both the AD and non-AD cases, depending on the subgroup. Therefore, precise subgrouping of both AD and non-AD patients should be performed, and this information should taken into consideration when interpreting the results of apoE genotyping.

Aged↗