Clinical Practice Guideline for Dementia (Diagnosis and Evaluation):2021 Revised Edition

no abstract available.

Clinical Application of Plasma Neurofilament Light Chain in a Memory Clinic: A Pilot Study

Background@#and Purpose: Neurofilament light chain (NfL) has been considered as a biomarker for neurodegenerative diseases including Alzheimer’s disease (AD). We measured plasma NfL levels in older adults with cognitive complaints and evaluated their clinical usefulness in AD. @*Methods@#Plasma levels of NfL, measured by using the single molecule array method, were acquired in a total of 113 subjects consisting of subjective cognitive decline (SCD; n=14), mild cognitive impairment (MCI; n=37), or dementia of Alzheimer type (DAT; n=62). Plasma NfL level was compared among three groups, and its association with cognitive and functional status was also analyzed. @*Results@#After adjusting for age, plasma NfL level was higher in subjects with DAT (65.98±84.96 pg/mL), compared to in subjects with SCD (16.90±2.54 pg/mL) or MCI (25.53±10.42 pg/mL, p=0.004). NfL levels were correlated with scores of the mini-mental state examination (r=−0.242, p=0.021), clinical dementia rating (CDR) (r=0.291, p=0.005), or CDR-sum of boxes (r=0.276, p=0.008). Just for participants who performed amyloid positron emission tomography (PET), the levels were different between subjects with PET (−) (n=17, 25.95±13.25 pg/mL) and PET (+) (n=16, 63.65±81.90 pg/mL, p=0.010). Additionally, plasma NfL levels were different between vascular dementia and vascular MCI, and between Parkinson’s disease- dementia and no dementia. @*Conclusions@#This pilot study shows that in subjects with DAT, plasma NfL levels increase.Plasma NfL level correlated with cognitive and functional status. Further longitudinal studies may help to apply the plasma NfL levels to AD, as a potential biomarker for the diagnosis and predicting progression.

Anatomical Correlates of the "Closing-In" Phenomenon

BACKGROUND AND PURPOSE: The "closing-in" phenomenon refers to the tendency to copy near or overlap a model while performing figure-copying tasks. The mechanisms underlying the closing-in phenomenon have not been fully elucidated, and previous studies only investigated the mechanisms through neuropsychological tests. We investigated the neuroanatomical correlates of the closing-in phenomenon using voxel-based morphometry (VBM). METHODS: Thirty-eight patients diagnosed with probable Alzheimer's disease (AD) and 21 normal controls were included. All subjects underwent neuropsychological testing to diagnose dementia and magnetization prepared rapid acquisition gradient echo brain magnetic resonance imaging for the voxel-based statistical analysis. The subjects were asked to copy the modified Luria's alternating squares and triangles to quantify the closing-in phenomenon. We applied SPM8 for the VBM analysis to detect gray matter loss associated with the closing-in phenomenon. RESULTS: The patients with probable AD showed a higher closing-in score than that of the normal control subjects (p<0.0001). The VBM analysis revealed more parietal and temporal atrophy in the patients with AD than that in the normal control group. Moreover, atrophy of the orbito-frontal area was associated with the closing-in phenomenon. CONCLUSIONS: The closing-in phenomenon is dysfunction while performing figure-copying tasks and is more common in patients with AD. The analysis of the orbito-frontal area, which is associated with inhibiting primitive reflexes, revealed that the closing-in phenomenon is an imitation behavior commonly observed in patients with frontal lobe damage.

Literacy Independent Cognitive Assessment: Assessing Mild Cognitive Impairment in Older Adults with Low Literacy Skills

OBJECTIVE: Comprehensive neuropsychological tests are important in the diagnosis and follow-up of patients with MCI; however, most were developed without consideration of illiteracy. We developed the Literacy Independent Cognitive Assessment (LICA) as a comprehensive neuropsychological assessment battery applicable to older adults who are either literate or illiterate. This study aimed to assess the reliability and validity of the LICA for diagnosis of MCI. METHODS: Normal controls (n=634) and patients with MCI (n=128) were recruited from 13 centers were included in this study. Participants were divided into illiterate or literate groups, based on their performance on a brief reading and writing test. The LICA, Korean Mini-Mental State Examination (K-MMSE), and Seoul Neuropsychological Screening Battery (SNSB) were administered. RESULTS: Total LICA scores distinguished MCI patients from controls (p<0.001). They were closely and positively correlated to the K-MMSE scores (r=0.632, p<0.001) but negatively correlated to clinical dementia rating (CDR) (r=-0.358, p<0.001) and CDR sum of boxes (r=-0.339, p<0.001). Area under the receiver operating characteristic curve for patients with MCI by total LICA score was 0.827 (0.783-0.870), superior to that presented by the K-MMSE. For the classification of MCI subtypes, inter-method reliability of LICA with the SNSB was good (kappa 0.773; 0.679-0.867, p<0.001). CONCLUSION: The results of this study show that the LICA may be reliably used to distinguish MCI patients from cognitively intact adults, to identify MCI subtypes and monitor progression toward dementia, regardless of illiteracy.

A Semi-Automated Method for Measuring White Matter Hyperintensity Volume

BACKGROUND: White matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) have been considered as a reliable biomarker of small vessel damages. To evaluate the severity of WMHs, it is vital to develop reliable methods to measure the volume of WMHs. We applied open source software to measure WMH volume in the semi-automated way, and tested the reliability and validity by comparing with the commonly used qualitative rating scale. METHODS: Twenty five subjects with variable WMHs were recruited. ANALYZE 10.0 was used for the image processing and volumetric measurement of WMHs. The inhomogeneity and artifacts of signal were corrected with Insight Segmentation and Registration Toolkit in ANALYZE. For the gold standard of the WMH volumetric measurement, threshold method was applied with consensus of manual editing on each slice of the MRI images by two raters. Histogram of the all slices of the Fluid Attenuated Inversion Recovery (FLAIR) MRI was generated to calculate the optimal voxel intensity of threshold, and the lowest voxel threshold was decided as the mean+1.4 SD. The volumes of WMHs were generated by multiplying the area and the thickness of each slice. Inter- and intrarater reliability of the semi-automated volumetric and Scheltens'methods, and the association between the individual methods were analyzed. RESULTS: The semi-automated WMH volume at the threshold of 1.4 SD as well as the gold standard volume was well correlated with the Scheltens' visual scale (r=0.75, p<0.001). The semi-automated volumetry showed the excellent intra-rater (ICC=0.9929; 95% CI, 0.9840-0.9968) and inter-rater reliability (ICC=0.9830; 95% CI, 0.9620-0.9925), superior to the Scheltens' visual rating scale. CONCLUSIONS: The semi-automated volume measurement of the WMHs with Analyze was a valid and a reliable method to quantify subcortical white matter damages of various etiologies.