Biomedical subjects

Jeanyung Chey

Publications and source records attributed to Jeanyung Chey.

3 recordsLinked to original sources

PubMed2005

Medial temporal lobe volume of nondemented elderly individuals with poor cognitive functions.

Poor cognitive performance of elderly individuals with low educational attainment is often difficult to interpret in dementia evaluation. Lack of education, as well as dementia, is often associated with poor cognitive test performance. To elucidate the underlying structural change of low cognitive performance in elderly individuals with low educational attainment, this study examined the relationship between low cognitive performance (LCP) and brain volumes, especially regions vulnerable to Alzheimer's disease, in nondemented elderly Koreans. Individuals with LCP (n=14) were matched on age and education with individuals with normal cognitive performance (n=14). The two groups were compared on the MR-based volumetric measures in the hippocampus, the entorhinal cortex, the amygdala, the temporal lobe, the frontal lobe, the cerebrum, and the intracranial cavity. Intracranial volume (p<.05) and absolute hippocampus (p<.05) and frontal lobe volumes (p<.05) were significantly reduced in individuals with LCP. Normalized volumes of the hippocampus and the frontal lobe did not differ in the two cognitive performance groups. ICV was associated with the K-DRS scores. General cognitive functioning of the LCP individuals, measured with the Korean version of the DRS, did not deteriorate in the 1- or 2-year follow-up cognitive tests. LCP in a nondemented elderly population with limited education appears to be associated with stable lower intelligence rather than increased risk for dementia of the Alzheimer's type.

Age Factors↗

PubMed2002

The validity and reliability of a Computerized Dementia Screening Test developed in Korea.

OBJECTIVE: This study was done to verify the validity and the reliability of the newly developed Computerized Dementia Screening Test (CDST) to be easily used in the primary care setting of Korea. DESIGN: Comparison of the results of CDST between 103 healthy control subjects and 41 patients who were diagnosed as having mild cognitive impairment or early dementia, having a clinical dementia rate of 0.5-1 from one health examination center and two neurology clinics in university hospitals. MEASUREMENTS: In order to estimate the criterion-related validity, logistic regression analysis for dementia was done using the four individual test results of CDST, age and educational level. The correlation between Korean Mini-Mental State Examination (K-MMSE) and the predicted probability of mild cognitive impairment and early dementia from the logistic regression was measured to verify its validity. The reliability of CDST was measured by test-retest reliability. RESULTS: The sensitivity and specificity of CDST were 75.6% and 94.2%, respectively, if the cut-off point was set to be 0.5 in the logistic regression model. The Pearson's Correlation Coefficient between K-MMSE and the predicted probability of mild cognitive impairment and early dementia from the logistic regression analysis was 0.59 (P<0.001). The overall test-retest reliability using the predicted probability of dementia from the logistic regression analysis of CDST was 0.89 (P=0.01). CONCLUSION: The validity and reliability of CDST is adequate for use as a screening tool to identify mild cognitive impairment and early dementia in Korean primary care.

Aged↗

PubMed2002

Spatial working memory span, delayed response and executive function in schizophrenia.

This study investigated the spatial working memory span (SWMS) as well as the immediate memory span of schizophrenic patients, and examined the contribution of each span to the patients' executive function deficit in the visuospatial domain. SWMS measured the visuospatial working memory capacity that simultaneously processes and stores visuospatial information. Immediate memory span was measured with the spatial span (SS), a variant of Corsi's block-tapping test. A total of 16 patients diagnosed with schizophrenia and 16 normal control subjects participated in the study. SWMS, as well as the forward and backward SS, was significantly reduced in schizophrenia. The SWMS deficit observed in this study and previous findings of deficit in verbal working memory spans suggest that impairment in working memory capacity in schizophrenia is general, and not limited to the verbal domain. Executive function as assessed with the self-ordered pointing task (SOPT) was also impaired in the patients, which is consistent with clinical observations of self-monitoring impairment in schizophrenia. SWMS was able to account for the performance on the SOPT, but its contribution in the patients' impairment did not reach statistical significance. Backward span deficit explained this executive function impairment. SWMS was effective in explaining schizophrenic patients' impaired performance on the spatial delayed response, a prefrontal function task. Implications of the relations observed between the spans and the prefrontal function tasks are discussed.

Adult↗