Miseon Kwon

Bio: Miseon Kwon is an academic researcher from University of Ulsan. The author has contributed to research in topics: Aphasia & Apraxia. The author has an hindex of 9, co-authored 29 publications receiving 581 citations.

Brief screening for mild cognitive impairment in elderly outpatient clinic: validation of the Korean version of the Montreal Cognitive Assessment.

Abstract: The Montreal Cognitive Assessment (MoCA) is a brief cognitive screening tool with high sensitivity for screening patients with mild cognitive impairment (MCI). The authors examined the validity and reliability of the Korean version of the MoCA (MoCA-K) in elderly outpatients. The MoCA-K, a Korean version of the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) scale, and neuropsychological batteries were administered to 196 elderly persons (mild Alzheimer's disease [AD] = 44, MCI = 37, normal controls [NC] = 115). MoCA-K scores were highly correlated with those of MMSE and CDR. Using a cutoff score of 22/23, the MoCA-K had an excellent sensitivity of 89% and a good specificity of 84% for screening MCI. Internal consistency and test-retest reliability were good. The results obtained show that the MoCA-K is brief, reliable, and suitable for use as a screening tool to screen MCI patients in elderly outpatient clinic settings.

Postoperative hypoalbuminemia as a risk factor for surgical site infection after oral cancer surgery.

Abstract: Objectives Postoperative surgical site infection (SSI) is a frequent postoperative complication in patients with oral cancer and significantly affects patient recovery and medical expenses. The aim of this study was to examine the predictors of SSI in patients undergoing major surgery for oral or oropharyngeal squamous cell carcinoma (OSCC) and to determine the relationship between perioperative albumin and the development of SSI. Subjects and methods In 337 consecutive patients who underwent clean-contaminated surgery for OSCC, serum albumin, glucose, and hemoglobin levels were perioperatively measured. Differences between the groups were examined using Fisher's exact test, Mann–Whitney U-test, and multiple logistic regression analysis. Results Surgical site infection was detected in 88 (26.1%) patients with median time to development of 10 (2–25) days. Multiple logistic regression analysis showed that only postoperative serum albumin < 2.5 g dl−1 was an independent variable predictive of SSI (P = 0.003). The duration of hospital stay was negatively correlated with postoperative albumin (R2 = –0.302, P < 0.001). Conclusion Early postoperative hypoalbuminemia <2.5 g dl−1 is an independent risk factor for the development of SSI in patients undergoing oral cancer surgery. Clinicians should be aware of the implications of postoperative hypoalbuminemia and consider more intensive postoperative care in these patients.

Oro-Pharyngeal Dysphagia in Parkinson's Disease and Related Movement Disorders.

Abstract: Oro-pharyngeal dysphagia is a common symptom in patients with Parkinson's disease (PD) and related disorders, even in their early stage of diseases. Dysphagia in these patients has been underdiagnosed, probably due to poor the self-awareness of the conditions and the underuse of validated tools and objective instruments for assessment. The early detection and intervention of dysphagia are closely related to improving the quality of life and decreasing the mortality rate in these patients. The purpose of this paper is to give an overview of the characteristics of dysphagia, including the epidemiology, pathophysiology, and clinical symptomatology, in patients with PD compared with other parkinsonian disorders and movement disorders. The management of dysphagia and future research directions related to these disorders are also discussed.

Subcortical Aphasia After Striatocapsular Infarction: Quantitative Analysis of Brain Perfusion SPECT Using Statistical Parametric Mapping and a Statistical Probabilistic Anatomic Map

Abstract: This study examined the relationship between the severity of aphasia and regional cerebral perfusion on brain SPECT using statistical parametric mapping (SPM) and a statistical probabilistic anatomic map (SPAM) in patients with a striatocapsular infarction (SCI) along with the other clinical and imaging findings. Methods: The subjects were 16 right-handed Korean-speaking patients with a left SCI who underwent 99mTc-ethylcyteinate dimer (99mTc-ECD) SPECT (8.1 ± 4.8 d [mean ± SD] after onset). MRI showed that no patient had any abnormality in the cerebral cortex (6.8 ± 6.0 d after onset). The aphasia quotient (AQ), which is a measure of the severity of aphasia, was obtained by using the Korean version of the Western Aphasia Battery (5.3 ± 3.9 d after onset). For quantitative evaluation of cerebral perfusion, the asymmetry indices (AIs) for subcortical and cortical areas were calculated using SPM and SPAM. The infarct size was measured using MRI. Results: Aphasia occurred in 15 (2 global, 7 transcortical, and 6 anomic aphasia) of the 16 patients. Left cerebral cortical hypoperfusion was observed in all 15 patients with subcortical aphasia. Aphasia was more severe in 6 patients with extensive cerebral cortical hypoperfusion than in the remaining 10 patients (AQ = 41.8 ± 25.2 points vs. 84.2 ± 7.7 points [mean ± SD], P = 0.001). There was an association between the AQ and age (ρ = −0.665), infarct size (ρ = −0.594), AIs of the frontal cortex (ρ = −0.653), temporal cortex (ρ = −0.782), parietal cortex (ρ = −0.694), whole cerebral cortex (ρ = −0.768), and the cerebellar cortex (ρ = 0.765). Voxel-based SPM analysis showed a significant positive correlation between the AQ and the perfusion of the left temporal cortex and the right cerebellum. Conclusion: The severity of subcortical aphasia after a left SCI without cortical abnormalities on MRI is associated with the extent and severity of the left cerebral cortical hypoperfusion on brain perfusion SPECT performed during the subacute stage, particularly in the left temporal cortex. Quantitative brain perfusion SPECT using SPM and SPAM can help in evaluating subcortical aphasia in a SCI because it provides functional information that cannot be obtained by morphologic imaging.

Gait freezing and speech disturbance in Parkinson's disease

Abstract: Gait freezing and speech disturbance are disabling axial features of Parkinson's disease (PD). However, the pathogenesis of these features remains unclear. We investigated the relation between changes in gait freezing and speech disturbance using visual and auditory cues in PD. 18 PD patients, comprising of 9 patients with freezing (PDGF) and 9 without gait freezing were studied. Patients performed a 7-m back-and-forth walk in a baseline state and with visual and auditory cues. Gait velocity, stride length and cadence were evaluated using a three-dimensional gait analysis system. For speech evaluation, patients read ten sentences in a baseline state and with visual and auditory cues. The time delay of speech initiation, speech rate and the number of repetitions per sentence were quantified. In PDGF patients, the increase in gait velocity positively correlated with the decrease in the time delay of the speech initiation. Also, the increase in the gait velocity and cadence positively correlated with the decrease in the number of repetitions per sentence. The increase in the stride length positively correlated with the increase in speech rate. Lastly, the increase in stride length positively correlated with the decrease in the number of repetitions per sentence. These findings suggest that there is a common pathomechanism of gait freezing and speech disturbance in PD.

Semantic dementia: progressive fluent aphasia with temporal lobe atrophy

Abstract: We report five patients with a stereotyped clinical syndrome characterized by fluent dysphasia with severe anomia, reduced vocabulary and prominent impairment of single-word comprehension, progressing to a stage of virtually complete dissolution of the semantic components of language. A marked reduction in the ability to generate exemplars from restricted semantic categories (e.g. animals, vehicles, etc.) was a consistent and early feature. Tests of semantic memory demonstrated a radically impoverished knowledge about a range of living and man-made items. In contrast, phonology and grammar of spoken language were largely preserved, as was comprehension of complex syntactic commands. Reading showed a pattern of surface dyslexia. Autobiographical and day-to-day (episodic) memory were relatively retained. Non-verbal memory, perceptual and visuospatial abilities were also strikingly preserved. In some cases, behavioural and personality changes may supervene; one patient developed features of the Kluver-Bucy Syndrome. Radiological investigations have shown marked focal temporal atrophy in all five patients, and functional imaging by single positron emission tomography and positron emission tomography (one case) have implicated the dominant temporal lobe in all five. In the older literature, such cases would have been subsumed under the rubric of Pick's disease. Others have been included in series with progressive aphasia. We propose the term semantic dementia, first coined by Snowden et al. (1989), to designate this clinical syndrome.

Normative data for the Montreal Cognitive Assessment (MoCA) in a population-based sample

Abstract: Objective: To provide normative and descriptive data for the Montreal Cognitive Assessment (MoCA) in a large, ethnically diverse sample. Methods: The MoCA was administered to 2,653 ethnically diverse subjects as part of a population-based study of cardiovascular disease (mean age 50.30 years, range 18–85; Caucasian 34%, African American 52%, Hispanic 11%, other 2%). Normative data were generated by age and education. Pearson correlations and analysis of variance were used to examine relationship to demographic variables. Frequency of missed items was also reviewed. Results: Total scores were lower than previously published normative data (mean 23.4, SD 4.0), with 66% falling below the suggested cutoff ( Conclusion: These findings highlight the need for population-based norms for the MoCA and use of caution when applying established cut scores, particularly given the high failure rate on certain items. Demographic factors must be considered when interpreting this measure.

A re-examination of Montreal Cognitive Assessment (MoCA) cutoff scores.

Abstract: Objective The Montreal Cognitive Assessment (MoCA; Nasreddine et al., 2005) is a cognitive screening tool that aims to differentiate healthy cognitive aging from Mild Cognitive Impairment (MCI). Several validation studies have been conducted on the MoCA, in a variety of clinical populations. Some studies have indicated that the originally suggested cutoff score of 26/30 leads to an inflated rate of false positives, particularly for those of older age and/or lower education. We conducted a systematic review and meta-analysis of the literature to determine the diagnostic accuracy of the MoCA for differentiating healthy cognitive aging from possible MCI. Methods Of the 304 studies identified, nine met inclusion criteria for the meta-analysis. These studies were assessed across a range of cutoff scores to determine the respective sensitivities, specificities, positive and negative predictive accuracies, likelihood ratios for positive and negative results, classification accuracies, and Youden indices. Results Meta-analysis revealed a cutoff score of 23/30 yielded the best diagnostic accuracy across a range of parameters. Conclusions A MoCA cutoff score of 23, rather than the initially recommended score of 26, lowers the false positive rate and shows overall better diagnostic accuracy. We recommend the use of this cutoff score going forward. Copyright © 2017 John Wiley & Sons, Ltd.

Cross validation of the Montreal Cognitive Assessment in community dwelling older adults residing in the Southeastern US

Abstract: Objective Cross validation study of the MoCA for the detection of Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) in a community-based cohort residing in the Southeastern United States. Methods One hundred and eighteen English-speaking older adults, who underwent diagnostic evaluation as part of an on-going prospective study, were administered the MoCA and MMSE. Twenty were diagnosed with AD, 24 met criteria for amnestic MCI and 74 were considered cognitively normal. Sensitivities and specificities were calculated using the recommended cut-off scores and ROC curve analyses were performed to determine optimal sensitivity and specificity. The influence of age, education and gender on MoCA score was also examined. Results Using a cut-off score of 24 or below, the MMSE was insensitive to cognitive impairment. Using the recommended cut-off score of 26, the MoCA detected 97% of those with cognitive impairment but specificity was fair (35%). Using a lower cut-off score of 23, the MoCA exhibited excellent sensitivity (96%) and specificity (95%). Conclusion The MoCA appears to have utility as a cognitive screen for early detection of AD and for MCI and warrants further investigation regarding its applicability in primary care settings, varying ethnic groups, and younger at-risk individuals. Copyright © 2008 John Wiley & Sons, Ltd.