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Background: Preclinical studies in transgenic models of Alzheimer’s disease (AD) suggest that DHP1401 has neuroprotective and memory-enhancing effects. Objective: To evaluate the efficacy and safety of DHP1401 in AD patients treated with donepezil Methods: Methods: In a double-blind study, patients with mild-to-moderate AD were randomized (1:1:1) to receive a twice daily total dose of 500 mg or 1000 mg DHP1401 or placebo for 24 weeks. Tolerability and safety were monitored at baseline and weeks 12 and 24. Results: total of 180 patients were randomized to Active 1 (500 mg: n = 62), Active 2 (1000 mg: n = 53), and control groups (n = 65) in 16 sites in Korea. There was no significant difference in the Alzheimer’s Disease Assessment Scale (ADAS-cog) score, the primary efficacy endpoint, from baseline. However, in the subgroup with mild AD patients (MMSE, 20–26) who received the high dose of DHP1401 and the group that received donepezil 5 mg, the ADAS-cog scores improved. MMSE and K-TMT-e type B were significant in both active groups at week 24. The most frequently observed symptom was dizziness (2.78%), and the most commonly observed reactions were related to metabolism and nutrition disorders (5.00%). No remarkable adverse events were observed for 24 weeks. Conclusion: Although the effectiveness of DHP1401 was not proved to be superior as the primary efficacy endpoint, the secondary endpoints, MMSE and K-TMT-e type B, showed significant beneficial effects. Also, the subgroups showed that ADAS-cog scores significantly were improved. DHP1401 could be proven beneficial for the AD treatment by further clinical trials.

Introduction: Subjective cognitive decline (SCD) is a self-reported cognitive decline without objective cognitive impairment. The relationship between audiometric hearing loss (HL) and cognitive function has not been reported in SCD. The purpose of this study was to investigate whether HL affects cognition-related indexes in SCD individuals. Methods: This is a cross-sectional study that used the baseline data of a multicenter cohort study that monitors clinical progression from SCD to dementia. Individuals aged ≥60 years who reported cognitive decline but had no objective cognitive impairment on comprehensive neuropsychological tests were recruited. Participants were grouped into the normal-hearing (NH) and bilateral HL groups. The demographics, clinical characteristics, dementia biomarkers, global cognition, questionnaire scores, neuropsychological test scores, and segmental brain volumes from MRI were compared between the groups. Results: Of a total of 120 participants, one hundred and two had NH (n = 57) or bilateral HL (n = 45). There were no group differences in the demographic and clinical data except the age. The biomarkers, global cognition, and questionnaire scores were not different between the groups. The HL group performed worse (the z-score of −0.06) in the Stroop Color Word Test than the NH group (0.27) (p = 0.025). Brain volumetric analysis revealed that the HL group had reduced gray matter volumes in four brain subregions: left temporal pole, left caudal middle frontal gyrus, left hippocampus, and right isthmus of the cingulate gyrus. Conclusion: In SCD, HL exerted an adverse effect on cognitive function, primarily frontal executive function tested in the Stroop task. HL was also related to gray matter volume reductions in brain subregions, although causality needs further investigation. This study may provide evidence for a potential link between hearing and cognition in SCD, an emerging clinical entity.

Introduction: Subjective cognitive decline (SCD) can be considered as the preclinical manifestation of Alzheimer’s disease (AD). The National Institute on Aging and the Alzheimer’s Association criteria for preclinical AD proposed that subtle cognitive changes appear along with AD biomarkers in the late stage of preclinical AD. The objective of this study was to explore whether subtle cognitive impairment (SCI) in individuals with SCD is associated with brain amyloid-β (Aβ) status and SCD severity. Methods: One hundred twenty individuals with SCD (mean age: 70.87 ± 6.10 years) were included in this study. SCI was defined as performance ≤ −1.0 SD on at least two neuropsychological tests. Participants underwent an amyloid positron emission tomography, which was assessed visually and quantitatively using standardized uptake value ratio (SUVR). The severity of SCD was assessed using two self-reported questionnaires: the SCD questionnaire based on the SCD-plus features and the Korean-Everyday Cognition (K-ECog) scale. Results: SCD individuals with SCI (n = 25) had more Aβ positivity than the SCD only group (n = 95) (44% vs. 15.79%; p = 0.002). In addition, the SCI group had a higher global SUVR than the SCD only group (p = 0.048). For self-reported questionnaires, there were no differences in SCD questionnaire total scores and K-ECog global and cognitive domain-specific scores between two groups. Conclusions: In SCD individuals, SCI was associated with higher Aβ positivity, but not with the severity of self-reported cognitive decline, compared to the SCD only group. These results suggest that the recognition of objectively defined subtle cognitive deficits may contribute to the early identification of AD in SCD.

Objective Patients with breathing-related sleep disorder (BRSD) often complain of psychiatric symptoms such as depression in addition to snoring, excessive sleepiness, and disturbed sleep. However, the relationship between psychiatric symptoms and severity of sleep apnea in BRSD is controversial. We conducted this study to investigate the relationship between psychiatric symptoms and sleep electroencephalography (EEG) findings in BRSD patients using spectral analysis. Methods All participants underwent polysomnography and evaluation using Symptom Checklist-90-Revised (SCL-90-R) scale. We analyzed the absolute spectral power density values of standard EEG frequency bands in the participants (n = 169) with BRSD during the non-rapid eye movement (NREM) sleep period. We performed correlation analysis between the domain scores of SCL-90-R scale and the absolute values of the EEG frequency bands. Results Significant positive correlation was observed between the absolute spectral power density values in the slow oscillation band and the degree of paranoid ideation (r = 0.226, p = 0.028) and depression (r = 0.216, p = 0.044) in SCL-90-R. The multiple linear regression model showed that higher paranoid ideation domain score (B = 0.007, p = 0.020), younger age (B = -0.011, p < 0.001), and female sex (B = 0.213, p = 0.004) were associated with higher slow oscillation power during NREM sleep. Conclusion The results of the present study suggested a relationship between sleep EEG and psychiatric symptoms in patients with BRSD. This relationship needs to be validated with further studies.

Background: Neurology in Korea is a field of clinical practice and research that has been developing for over 30 years, but due to its relatively short history, public awareness is low compared to other clinical fields. The Korean Neurological Association conducted a survey to evaluate the Korean public’s awareness of neurology and the necessity of a name change. This study details the second survey conducted on the topic, with the first being conducted in 2013. The two surveys were compared to identify how the public’s awareness of neurology has improved since 2013 and determine how this can be improved.Methods: The survey was conducted by Gallup Korea, where 1,000 participants were randomly selected and interviewed through telephone surveys.Results: Of the 1,000 participants, 78.5% were familiar with Neurology, similar to the results of the 2013 survey. Meanwhile, when asked about neurological diseases, only 27.9% of the participants recognized neurological diseases correctly. The most accurately recognized symptoms related to Neurology were tremors (57.8%), strokes (55.5%), and dizziness (49.7%). In 2013, 61.7% of the participants thought a name change was necessary. In comparison, only 38.4% responded it needed to change in the recent survey.Conclusions: The preference for Neurology’s current name in Korea has improved since 2013 despite no significant change in the public’s awareness of neurology. More active public relations activities are needed to improve awareness of neurology in the future.

BACKGROUND AND PURPOSE Reportedly 30-50% of patients being treated for chronic illnesses do not adhere to their medication regimen. We assessed the impact of a nurse-led education program for caregivers of Korean de novo Alzheimer's disease patients who had newly been prescribed donepezil. METHODS This multicenter study analyzed 93 participants in a caregiver education group and 92 participants in a caregiver no-education group. At every visit up to the end of the study (1 year), caregivers in the education group were given educational brochures regarding Alzheimer's disease and the efficacy and adverse events of donepezil treatment. The primary endpoint was the discontinuation rate of donepezil treatment during the 1-year observation period. The secondary endpoints included the effect of education on compliance with donepezil treatment assessed at each visit using a clinician rating scale (CRS) and visual analog scale (VAS), and changes from baseline in cognitive assessment tests. RESULTS The donepezil discontinuation rates at 1 year were 5.38% (5/93) and 6.52% (6/92) in the caregiver education and no-education groups, respectively (p=0.742). No significant between-group differences in donepezil compliance rates on the CRS and VAS were observed, but significant changes were observed in some cognitive tests from baseline to the end of the study. CONCLUSIONS Caregiver education had no significant effect on treatment discontinuation, but this may have been due to the low severity of cognitive impairment among the included population at baseline. In addition, the low discontinuation rates meant that no significant difference in treatment compliance was observed.

BACKGROUND AND PURPOSE The rate of donepezil discontinuation and the underlying reasons for discontinuation in Asian patients with Alzheimer's disease (AD) are currently unknown. We aimed to determine the treatment discontinuation rates in AD patients who had newly been prescribed donepezil in routine clinical practice in Asia. METHODS This 1-year observational study involved 38 institutions in seven Asian countries, and it evaluated 398 participants aged 50-90 years with a diagnosis of probable AD and on newly prescribed donepezil monotherapy. The primary endpoint was the rate of donepezil discontinuation over 1 year. Secondary endpoints included the reason for discontinuation, treatment duration, changes in cognitive function over the 1-year study period, and compliance as assessed using a clinician rating scale (CRS) and visual analog scale (VAS). RESULTS Donepezil was discontinued in 83 (20.9%) patients, most commonly due to an adverse event (43.4%). The mean treatment duration was 103.67 days in patients who discontinued. Among patients whose cognitive function was assessed at baseline and 1 year, there were no significant changes in scores on the Mini-Mental State Examination, Montreal Cognitive Assessment, and Trail-Making Test-Black and White scores, whereas the Clinical Dementia Rating score increased significantly (p

Subjective cognitive decline (SCD) refers to the self-perception of cognitive decline with normal performance on objective neuropsychological tests. SCD, which is the first help-seeking stage and the last stage before the clinical disease stage, can be considered to be the most appropriate time for prevention and treatment. This study aimed to compare characteristics between the amyloid positive and amyloid negative groups of SCD patients.A cohort study to identify predictors for the clinical progression to mild cognitive impairment (MCI) or dementia from subjective cognitive decline (CoSCo) study is a multicenter, prospective observational study conducted in the Republic of Korea. In total, 120 people aged 60 years or above who presented with a complaint of persistent cognitive decline were selected, and various risk factors were measured among these participants. Continuous variables were analyzed using the Wilcoxon rank-sum test, and categorical variables were analyzed using the χThe multivariate logistic regression model indicated that amyloid positivity on PET was related to a lack of hypertension, atrophy of the left temporal lateral and entorhinal cortex, low body mass index, low waist circumference, less body and visceral fat, fast gait speed, and the presence of the apolipoprotein E ε4 allele in amnestic SCD patients.The CoSCo study is still in progress, and the authors aim to identify the risk factors that are related to the progression of MCI or dementia in amnestic SCD patients through a two-year follow-up longitudinal study.

Early detection of subjective cognitive decline (SCD) due to Alzheimer's disease (AD) is important for clinical research and effective prevention and management. This study examined if quantitative electroencephalography (qEEG) could be used for early detection of AD in SCD.Participants with SCD from 6 dementia clinics in Korea were enrolled.The present study included 95 participants aged over 65 years, including 26 amyloid PET (+) and 69 amyloid PET (-). In participants with amyloid PET (+), relative power at delta band was higher in frontal (SCD participants with amyloid PET (+) showed increased delta and decreased alpha 1 activity. qEEG is a potential means for predicting amyloid pathology in SCD. Further longitudinal studies are needed to confirm these findings.

Background: Frontotemporal dementia (FTD) syndrome is a genetically heterogeneous group of diseases. Pathogenic variants in the chromosome 9 open reading frame 72 (C9orf72), microtubule-associated protein tau (MAPT), and progranulin (GRN) genes are mainly associated with genetic FTD in Caucasian populations. Objective: To understand the genetic background of Korean patients with FTD syndrome. Methods: We searched for pathogenic variants of 52 genes related to FTD, amyotrophic lateral sclerosis, familial Alzheimer’s disease, and other dementias, and hexanucleotide repeats of the C9orf72 gene in 72 Korean patients with FTD using whole exome sequencing and the repeat-primed polymerase chain reaction, respectively. Results: One likely pathogenic variant, p.G706R of MAPT, in a patient with behavioral variant FTD (bvFTD) and 13 variants of uncertain significance (VUSs) in nine patients with FTD were identified. Of these VUSs, M232R of the PRNP gene, whose role in pathogenicity is controversial, was also found in two patients with bvFTD. Conclusions: These results indicate that known pathogenic variants of the three main FTD genes (MAPT, GRN, and C9orf72) in Western countries are rare in Korean FTD patients.

Oral administration of cholinesterase inhibitors is often associated with adverse gastrointestinal effects, and so developing an alternative administration route, such as transdermal, is urgently needed. The primary objective of this study was to determine the efficacy and safety of the IPI-301 donepezil transdermal patch compared with donepezil tablets (control) in mild-to-moderate probable Alzheimer's disease (AD).This prospective, randomized, double-blind, double-dummy, two-arm parallel, multicenter trial included 399 patients, among whom 303 completed the trial. For randomization, the patients were stratified based on previous treatment and donepezil dose; patients in each stratum were randomized to the test and control groups at a 1:1 ratio.The difference between the control group and the IPI-301 group, quantified as the Hodges-Lehmann estimate of location shift, was 0.00 (95% confidence interval: -1.00 to 1.33), with an upper limit of less than 2.02. The change in Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) score differed significantly between the IPI-301 and control groups (IPI-301 was safe and efficacious in improving cognitive function in patients with mild-to-moderate AD.

National dementia plans were applied in dementia support centers established in Seoul, Korea between 2007 and 2009. However, the annual incidence rates of dementia in Seoul have not been reported. We investigated this annual incidence and the characteristics of incident cases from 2003 to 2018. The customized research database of the Korean National Health Insurance Services was used. The annual crude and age-standardized incidence of dementia patients and their characteristics were analyzed. This study analyzed 108,596 incident dementia cases aged ≥60 years. The incidence rate increased from 2003 to 2011, including a rapid increment from 2007 to 2011. From 2011 to 2018, the crude (age-standardized) incidence per 105 person-years decreased from 641.51 (577.12) to 448.26 (361.23). The proportion of incident dementia cases was highest in the highest income group every year. However, the proportion of incident dementia cases in the lowest income group increased from 10.4% in 2003 to 25.8% in 2011. The annual incidence rate of dementia showed a sharp increase immediately after 2007, the year dementia support centers began to be introduced, and then stabilized after 2011. The characteristics of incident dementia cases have changed, including the proportion in the low-income group.

Background and Purpose: Cerebral small vessel disease is characterized by progressive cerebral white matter changes (WMCs). This study aimed to compare the effects of cilostazol and aspirin on changes in WMC volume in patients with cerebral small vessel disease. Methods: In a multicenter, double-blind, randomized controlled trial, participants with moderate or severe WMCs and at least one lacunar infarction detected on brain magnetic resonance imaging were randomly assigned to the cilostazol and aspirin groups in a 1:1 ratio. Cilostazol slow release (200 mg) or aspirin (100 mg) capsules were administered once daily for 2 years. The primary outcome was the change in WMC volume on magnetic resonance images from baseline to 2 years. Secondary imaging outcomes include changes in the number of lacunes or cerebral microbleeds, fractional anisotropy, and mean diffusivity on diffusion tensor images, and brain atrophy. Secondary clinical outcomes include all ischemic strokes, all ischemic vascular events, and changes in cognition, motor function, mood, urinary symptoms, and disability. Results: Between July 2013 and August 2016, 256 participants were randomly assigned to the cilostazol (n=127) and aspirin (n=129) groups. Over 2 years, the percentage of WMC volume to total WM volume and the percentage of WMC volume to intracranial volume increased in both groups, but neither analysis showed significant differences between the groups. The peak height of the mean diffusivity histogram in normal-appearing WMs was significantly reduced in the aspirin group compared with the cilostazol group. Cilostazol significantly reduced the risk of ischemic vascular event compared with aspirin (0.5 versus 4.5 cases per 100 person-years; hazard ratio, 0.11 [95% CI, 0.02–0.89]). Conclusions: There was no significant difference between the effects of cilostazol and aspirin on WMC progression in patients with cerebral small vessel disease. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01932203.

Background Telomeres are repetitive DNA sequences of TTAGGG at the ends of chromosomes. Many studies have shown that telomere shortening is associated with aging-related diseases, such as cardiovascular diseases, hypertension, diabetes, cancer, and various neurodegenerative diseases, including Alzheimer's disease, vascular dementia, Parkinson's disease, and dementia with Lewy bodies. However, changes in telomere length (TL) in patients with frontotemporal dementia (FTD) syndrome are unclear. Accordingly, in this study, we assessed TL in blood samples from patients with FTD syndrome. Methods Absolute TL was measured in peripheral blood leukocytes from 53 patients with FTD syndromes (25 with behavioral variant FTD, 19 with semantic variant primary progressive aphasia [PPA], six with nonfluent/agrammatic variant PPA, and three with amyotrophic lateral sclerosis [ALS] plus) and 28 cognitively unimpaired (CU) controls using terminal restriction fragment analysis. Results TL was significantly longer in the FTD group than in the CU group. All FTD subtypes had significantly longer TL than controls. There were no significant differences in TL among FTD syndromes. No significant correlations were found between TL and demographic factors in the FTD group. Conclusions Longer telomeres were associated with FTD syndrome, consistent with a recent report demonstrating that longer telomeres are related to ALS. Therefore, our results may support a shared biology between FTD and ALS. More studies with larger sample sizes are needed.

Background and purpose Behavioral variant frontotemporal dementia (bvFTD) is a subtype of frontotemporal dementia, which has clinical symptoms of progressive personality and behavioral changes with deterioration of social cognition and executive functions. The pathology of bvFTD is known to be tauopathy or TDP-43 equally. We analyzed the 18F-THK5351 positron emission tomography (PET) scans, which were recently developed tau PET, in patients with clinically-diagnosed bvFTD. Methods Forty-eight participants, including participants with behavioral variant frontotemporal dementia (bvFTD, n=3), Alzheimer's disease (AD, n=21) and normal cognition (NC, n=24) who completed 3T magnetic resonance images, 18F-THK5351 PET scans, and detailed neuropsychological tests were included in the study. Voxel-wise statistical analysis and region of interest (ROI)-based analyses were performed to evaluate the retention of THK in bvFTD patients. Results In the voxel-based and ROI-based analyses, patients with bvFTD showed greater THK retention in the prefrontal, medial frontal, orbitofrontal, anterior cingulate, insula, anterior inferior temporal and striatum regions compared to NC participants. Left-right asymmetry was noted in the bvFTD patients. A patient with extrapyramidal symptoms showed much greater THK retention in the brainstem. Conclusions The distribution of THK retention in the bvFTD patients was mainly in the frontal, insula, anterior temporal, and striatum regions which are known to be the brain regions corresponding to the clinical symptoms of bvFTD. Our study suggests that 18F-THK5351 PET imaging could be a supportive tool for diagnosis of bvFTD.

We investigated the survival time of each clinical syndrome of frontotemporal dementia (FTD) and the impacts of behavioral and motor features on survival of FTD. A total of 216 patients with FTD [82 behavioral variant FTD (bvFTD), 78 semantic variant primary progressive aphasia (svPPA), 43 non-fluent/agrammatic variant PPA (nfvPPA), 13 FTD-motor neuron disease (MND)] were enrolled from 16 centers across Korea. Behaviors and parkinsonism were assessed using the Frontal Behavioral Inventory and Unified Parkinson’s Disease Rating Scale Part III, respectively. The Kaplan–Meier method was used for the survival analysis and the Cox proportional hazards model was applied for analysis of the effect of behavioral and motor symptoms on survival, after controlling vascular risk factors and cancer. An overall median survival of FTD was 12.1 years. The survival time from onset was shortest for FTD-MND and longest for svPPA. The median survival time of patients with bvFTD was unavailable but likely comparable to that of patients with nfvPPA. In the bvFTD group, negative behavioral symptoms and akinetic rigidity were significantly associated with survival. In the nfvPPA group, the presence of dysarthria had a negative impact on survival. These findings provide useful information to clinicians planning for care.

Background and purpose To analyze 18F-THK5351 positron emission tomography (PET) scans of patients with clinically diagnosed nonfluent/agrammatic variant primary progressive aphasia (navPPA). Methods Thirty-one participants, including those with Alzheimer's disease (AD, n=13), navPPA (n=3), and those with normal control (NC, n=15) who completed 3 Tesla magnetic resonance imaging, 18F-THK5351 PET scans, and detailed neuropsychological tests, were included. Voxel-based and region of interest (ROI)-based analyses were performed to evaluate retention of 18F-THK5351 in navPPA patients. Results In ROI-based analysis, patients with navPPA had higher levels of THK retention in the Broca's area, bilateral inferior frontal lobes, bilateral precentral gyri, and bilateral basal ganglia. Patients with navPPA showed higher levels of THK retention in bilateral frontal lobes (mainly left side) compared than NC in voxel-wise analysis. Conclusions In our study, THK retention in navPPA patients was mainly distributed at the frontal region which was well correlated with functional-radiological distribution of navPPA. Our results suggest that tau PET imaging could be a supportive tool for diagnosis of navPPA in combination with a clinical history.

BACKGROUND AND PURPOSE Visual assessment of medial temporal-lobe atrophy (MTA) has been quick, reliable, and easy to apply in routine clinical practice. However, one of the limitations in visual assessments of MTA is the lack of widely accepted age-adjusted norms and cutoff scores for MTA for a diagnosis of Alzheimer's disease (AD). This study aimed to determine the optimal cutoff score on a T1-weighted axial MTA Visual Rating Scale (VRS) for differentiating patients with AD from cognitively normal elderly people. METHODS The 3,430 recruited subjects comprising 1,427 with no cognitive impairment (NC) and 2003 AD patients were divided into age ranges of 50-59, 60-69, 70-79, and 80-89 years. Of these, 446 participants (218 in the NC group and 228 in the AD group) were chosen by random sampling for inclusion in this study. Each decade age group included 57 individuals, with the exception of 47 subjects being included in the 80- to 89-year NC group. The scores on the T1-weighted axial MTA VRS were graded by two neurologists. The cutoff values were evaluated from the area under the receiver operating characteristic curve. RESULTS The optimal axial MTA VRS cutoff score from discriminating AD from NC increased with age: it was ≥as ≥1, ≥2, and ≥3 in subjects aged 50-59, 60-69, 70-79, and 80-89 years, respectively (all p

BACKGROUND Semantic variant primary progressive aphasia (svPPA) has been associated with a variety of proteinopathies, mainly transactive response DNA-binding protein, but also with tau and β-amyloid. Recently selective tau tracers for positron emission tomography (PET) have been developed to determine the presence of cerebral tau deposits in vivo. Here, we investigated the topographical distribution of THK5351 in svPPA patients. MATERIALS AND METHODS Five svPPA patients, 14 Alzheimer's disease patients, and 15 age-matched normal controls underwent [F]-THK5351 PET scans, magnetic resonance imaging, and detailed neuropsychological tests. [F]-fluorodeoxyglucose PET was obtained in 3 svPPA patients, whereas the remaining 2 underwent amyloid PET using [F]-flutemetamol. Tau distribution among the 3 groups was compared using regions of interest-based and voxel-based statistical analyses. RESULTS In svPPA patients, [F]-THK5351 retention was elevated in the anteroinferior and lateral temporal cortices compared with the normal controls group (left>right), and in the left inferior and temporal polar region compared with Alzheimer's disease patients. [F]-THK5351 retention inversely correlated with glucose metabolism, whereas regional THK retention correlated with clinical severity. [F]-flutemetamol scans were negative for β-amyloid. CONCLUSIONS These findings show that [F]-THK5351 retention may be detected in cortical regions correlating with svPPA pathology.

This study aims to evaluate the clinical validity of [18F]THK5351 positron emission tomography (PET) for the assessment of disease progression and symptoms in Alzheimer's disease (AD). Fifty-one patients with AD dementia, 30 patients with amnestic mild cognitive impairment (aMCI), and 43 controls with normal cognition (NC) were included. All subjects underwent [18F]THK5351 PET, 3.0-T magnetic resonance imaging, and detailed neuropsychological tests. Regions of interest and voxel-based statistical analyses were performed. In patients with AD dementia, [18F]THK5351 retention was greater in most association cortices as well as the limbic area compared to NC or aMCI participants. Patients with aMCI also showed higher THK5351 retention in those areas compared to NC. [18F]THK5351 retention significantly correlated with neuropsychological test results. Negative correlations between [18F]THK5351 and [18F] fluorodeoxyglucose were observed in AD dementia and aMCI groups. Mirror images of [18F]THK5351 retention and glucose hypometabolism in [18F] fluorodeoxyglucose were noticeable in the focal variants of AD. [18F]THK5351 PET reflects disease severity and symptoms in AD. Our results suggest [18F]THK5351 is reflective of tau-related AD pathology.

Background and purpose Although progression of small deep subcortical infarct (PSDI) comprises 12% to 36% of all small deep subcortical infarcts, the therapy for progression is not clear. This study investigated whether induced-hypertension therapy using phenylephrine is a useful therapy for PSDI. Methods A group of 2427 consecutive patients, diagnosed with stroke at a tertiary hospital over a period of 4 years was reviewed retrospectively. We analyzed patients with small deep subcortical infarct using clinical, laboratory, and pulse wave velocity (PWV). PSDI is defined as one or more increase in the motor score according to the NIHSS. Good outcome was designated as a modified Rankin scale of 0 to 2 at discharge. Results Among all 662 patients who had a small deep subcortical infarct, 66 patients experienced motor progression (9.97%). The induced-hypertension therapy group (n = 25) received phenylephrine, and the conventional group (n = 41) received anticoagulation therapy such as heparin, volume expansion, or both. Although there were no significant differences in baseline clinical and laboratory findings, the PSDI group showed a significantly more frequent decrease in blood pressure at progression ( P P = 0.001). The phenylephrine group ( vs the conventional group) had a lower NIHSS score ( P = 0.036) and good outcome at discharge ( P = 0.004). In multiple regression analysis, PWV (OR, 1.004 per 1-cm/s increase; 95% CI, 1.001–1.008; P = 0.018) was an independent predictor of good outcome in the phenylephrine group. A side effect of phenylephrine treatment was dysuria (n = 1). Conclusions The present study suggests that vascular stiffness can be not only a predictor for PSDI but also a predictor of motor improvement after induced-hypertension therapy using phenylephrine in lacunar stroke.

Patients with simple snoring (SS) often complain of poor sleep quality despite a normal apnoea-hypopnoea index (AHI). We aimed to identify the difference in power spectral density of electroencephalography (EEG) between patients with SS and those with obstructive sleep apnoea (OSA). We compared the absolute power spectral density values of standard EEG frequency bands between the SS (n = 42) and OSA (n = 129) groups during the non-rapid eye movement (NREM) sleep period, after controlling for age and sex. We also analysed partial correlation between AHI and the absolute values of the EEG frequency bands. The absolute power spectral density values in the beta and delta bands were higher in the OSA group than in the SS group. AHI also positively correlated with beta power in the OSA group as well as in the combined group (OSA + SS). In conclusion, higher delta and beta power during NREM sleep were found in the OSA group than in the SS group, and beta power was correlated with AHI. These findings are microstructural characteristics of sleep-related breathing disorders.

Background and purpose We aimed to determine the reliability and validity of a short form of the Korean Dementia Screening Questionnaire-Cognition (KDSQ-C) as a screening tool for cognitive dysfunction. Methods This study recruited 420 patients older than 65 years and their informants from 11 hospitals, and categorized the patients into normal cognition, mild cognitive impairment, and dementia subgroups. The KDSQ-C was completed separately by the patients and their informants. We abstracted three components of the KDSQ-C and combined these components into the following four subscales: KDSQ-C-I (items 1-5, memory domain), KDSQ-C-II (items 1-5 & 11-15, memory domain+activities of daily living), KDSQ-C-III (items 1-5 & 6-10, memory domain+other cognitive domains), and KDSQ-C-IV (items 6-10 & 11-15, other cognitive domains+activities of daily living). The reliability and validity were compared between these four subscales. Results A receiver operating characteristic (ROC) analysis of questionnaire scores provided by the patients showed that the areas under the ROC curves (AUCs) for the KDSQ-C, KDSQC-I, and KDSQ-C-II for diagnosing dementia were 0.75, 0.72, and 0.76, respectively; the corresponding AUCs for informant-completed questionnaires were 0.92, 0.89, and 0.92, indicating good discriminability for dementia. Conclusions A short form of the patient- and informant-rated versions of the KDSQ-C (KDSQ-C-II) is as capable as the 15-item KDSQ-C in screening for dementia.

OBJECTIVES The present study examined self-reports and informant reports of cognitive function and discrepancies between the two reporting methods in healthy controls (HC), subjective cognitive decline (SCD), mild cognitive impairment (MCI), and very mild Alzheimer disease (AD) using three questionnaires. METHODS The study included a total of 300 individuals (mean age: 74.4 ± 5.7 y), including 130 HC, 70 SCD, 51 MCI, and 49 very mild AD patients. Self-ratings and informant ratings of cognitive function were assessed using the Korean Dementia Screening Questionnaire-Cognition (KDSQ-C), AD8, and Subjective Memory Complaints Questionnaire (SMCQ). Awareness of cognitive functioning was measured on the basis of the discrepancy scores between self-reports and informant reports. RESULTS Group comparisons on questionnaire scores adjusting for age, education, and depressive symptoms showed that self-reports were lowest in HC than other groups, with no differences between SCD and MCI groups. Informant reports were lower in SCD than in MCI, while discrepancy scores were higher in SCD than in MCI (P

Background We investigated the prevalence of parkinsonism in frontotemporal dementia (FTD) subtypes and the cognitive and behavioral differences between FTD with and without parkinsonism in a well-structured, prospective cohort. Methods One hundred and ninety-one FTD patients were enrolled and all patients underwent comprehensive neurological evaluations, neuropsychological tests, and the Unified Parkinson's Disease Rating Scale. Results The prevalence of parkinsonism was 38.7% (74 patients), and included 33 (46.5%) behavioral variant FTD (bvFTD), 16 (24.2%) semantic dementia (SD), 19 (45.2%) progressive nonfluent aphasia (PNFA), and 6 (50%) FTD associated with motor neuron disease (FTD-MND). SD patients with parkinsonism had higher CDR sum of boxes scores (9.7 ± 4.5 vs 6.2 ± 4.5, p = 0.024), frontal behavioral inventory total score (33.7 ± 20.5 vs 24.3 ± 14.5, p = 0.045), and executive function score of frontal executive dysfunction, disinhibition, and apathy (28.9 ± 13.7 vs 19.2 ± 12.9, p = 0.021) than those without parkinsonism. Seoul Instrumental Activities of Daily Living score (bvFTD: 23.5 ± 11.7 vs 17.3 ± 11.3, p = 0.031, SD: 23.1 ± 11.1 vs 11.3 ± 9.3, p = 0.005) was higher for bvFTD and SD with parkinsonism than for those without parkinsonism. Conclusions Parkinsonism is found to be more common in patients with bvFTD, PNFA, and FTD-MND patients than those with SD. Behavioral disturbances were more prominent in SD with parkinsonism than without. Additional studies are needed to determine the pathomechanism and optimal treatment of parkinsonism in different FTD subtypes.

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by the loss of muscle atonia during REM sleep and dream enactment, which often leads to injury of the patient or the bed partner [1]. Although its precise pathophysiology is unclear, RBD occurs more frequently in patients with neurodegenerative disease than in the general population, and especially in patients with α-synucleinopathy such as Parkinson’s disease (PD), multiple systemic atrophy (MSA), and dementia with Lewy bodies (DLB) compared to non-synucleinopathy. A number of studies have attempted to reveal the association between RBD and α-synucleinopathies [2-4]. Up to 81% of the patients initially diagnosed with idiopathic RBD eventually developed neurodegenerative diseases in long-term follow-up studies [5,6]. Therefore, RBD is becoming recognized as a clinical predictive factor for neurodegenerative diseases [7,8]. RBD has been reported to be present in 15–72% of PD patients and is associated with poor parkinsonian symptoms, higher daily levodopa dosage, poor autonomic symptoms and cognitive impairment in PD patients [2,9-13]. In this study, we aimed to assess the differences in the clinical characteristics between PD patients with and without RBD in a Korean population. Although a definite diagnosis of RBD requires polysomnography (PSG), this technique is unsuitable for studies dealing with large populations or clinical settings because the exam is expensive and requires a skilled examiner. For this reason, various RBD screening tools, including the RBD screening questionnaire (RBDSQ), RBD questionnaire-Hong Kong, Mayo sleep questionnaire, and RBD Severity Scale have been developed and utilized in RBD studies [14]. In 2007, Stiasny-Kolster et al. [15] proposed the RBDSQ, a 10-item, patient self-rating tool that has demonstrated a high sensitivity and reasonable specificity for RBD diagnosis as confirmed by PSG. For this study, the Korean version of the RBDSQ (RBDSQ-K) has been developed and utilized for assessment of RBD in PD patients. Although the importance of RBD as predicting factor for PD is becoming more recognized and the number of studies examining the clinical characteristics of RBD patients continues to increase, there are only a few RBD studies in the Korean PD population. In this study, we aimed to analyze the differences in the clinical characteristics of PD patients with and without RBD.

Background and purpose Screening tests for dementia such as the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment are widely used, but there are drawbacks to their efficient use. There remains a need for a brief and easy method of assessing the activities of daily living (ADL) that can be administered to elderly individuals by healthcare workers. We have therefore developed a new scale named the Simple Observation Checklist for Activities of Daily Living (SOC-ADL). Methods We developed the SOC-ADL scale as a team of experts engaged in caring for individuals with dementia. This scale comprises eight items and was designed based on the Korean instrumental activities of daily living (K-IADL) scale and the Barthel activities of daily living scale (Barthel Index). The new scale was validated by enrolling 176 patients with cognitive dysfunction across 6 centers. Confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were performed. We assessed its concurrent validity by performing comparisons with the Korean-MMSE, Clinical Dementia Rating, Clinical Dementia Rating-Sum of Boxes, K-IADL, and Barthel Index, and its criterion validity by performing comparisons between mild cognitive impairment (MCI) and dementia. We also used Cronbach's alpha to assess the interitem reliability. The appropriate cutoff values were determined by analyzing receiver operating characteristic curves, including the areas underneath them. Results EFA extracted one factor and CFA revealed that all of the model fits exceeded the minimum acceptable criteria. The SOC-ADL scores were strongly correlated with those of the other tools for dementia and could be used to differentiate MCI from dementia. Cronbach's alpha values indicated that the results were reliable. The optimal cutoff value of the SOC-ADL for discriminating dementia from MCI was 3 points, which provided a sensitivity and specificity of 74.5% and 75.7%, respectively. Conclusions Our results demonstrate that the SOC-ADL is a valid and reliable tool for differentiating dementia from MCI based on an assessment of ADL. This new tool can be used for screening ADL in elderly subjects who have difficulty communicating, and to increase the efficiency of dementia screening at the population level.

Background Korea has a periodic general health check-up program that uses the Korean Dementia Screening Questionnaire-Cognition (KDSQ-C) as a cognitive dysfunction screening tool. The Alzheimer Disease 8 (AD8) and Subjective Memory Complaints Questionnaire (SMCQ) are also used in clinical practice. We compared the diagnostic ability of these screening questionnaires for cognitive impairment when completed by participants and their caregivers. Hence, we aimed to evaluate whether the SMCQ or AD8 is superior to the KDSQ-C and can be used as its replacement. Methods A total of 420 participants over 65 years and their informants were recruited from 11 hospitals for this study. The patients were grouped into normal cognition, mild cognitive impairment, and dementia subgroups. The KDSQ-C, AD8, and SMCQ were completed separately by participants and their informants. Results A receiver operating characteristic analysis of questionnaire scores completed by participants showed that the areas under the curve (AUCs) for the KDSQ-C, AD8, and SMCQ for diagnosing dementia were 0.75, 0.8, and 0.73, respectively. Regarding informant-completed questionnaires, the AD8 (AUC of 0.93), KDSQ-C (AUC of 0.92), and SMCQ (AUC of 0.92) showed good discriminability for dementia, with no differences in discriminability between the questionnaires. Conclusion When an informant-report is possible, we recommend that the KDSQ-C continues to be used in national medical check-ups as its discriminability for dementia is not different from that of the AD8 or SMCQ. Moreover, consistent data collection using the same questionnaire is important. When an informant is not available, either the KDSQ-C or AD8 may be used. However, in the cases of patient-reports, discriminability is lower than that for informant-completed questionnaires., Graphical Abstract

Background and Purpose Mild cognitive impairment (MCI) is a condition with diverse clinical outcomes and subgroups. Here we investigated the topographic distribution of tau in vivo using the positron emission tomography (PET) tracer [18F]THK5351 in MCI subgroups. Methods This study included 96 participants comprising 38 with amnestic MCI (aMCI), 21 with nonamnestic MCI (naMCI), and 37 with normal cognition (NC) who underwent 3.0-T MRI, [18F]THK5351 PET, and detailed neuropsychological tests. [18F]flutemetamol PET was also performed in 62 participants. The aMCI patients were further divided into three groups: 1) verbal-aMCI, only verbal memory impairment; 2) visual-aMCI, only visual memory impairment; and 3) both-aMCI, both visual and verbal memory impairment. Voxel-wise statistical analysis and region-of-interest -based analyses were performed to evaluate the retention of [18F]THK5351 in the MCI subgroups. Subgroup analysis of amyloid-positive and -negative MCI patients was also performed. Correlations between [18F]THK5351 retention and different neuropsychological tests were evaluated using statistical parametric mapping analyses. Results [18F]THK5351 retention in the lateral temporal, mesial temporal, parietal, frontal, posterior cingulate cortices and precuneus was significantly greater in aMCI patients than in NC subjects, whereas it did not differ significantly between naMCI and NC participants. [18F] THK5351 retention was greater in the both-aMCI group than in the verbal-aMCI and visualaMCI groups, and greater in amyloid-positive than amyloid-negative MCI patients. The cognitive function scores were significantly correlated with cortical [18F]THK5351 retention. Conclusions [18F]THK5351 PET might be useful for identifying distinct topographic patterns of [18F]THK5351 retention in subgroups of MCI patients who are at greater risk of the progression to Alzheimer's dementia.

Background Although plasma amyloid-β (Aβ) levels have been evaluated as a possible diagnostic marker of Alzheimer's disease (AD), the findings are inconsistent. Objective The present study aimed to validate plasma levels of Aβ40, Aβ42, and the Aβ40/Aβ42 ratio as biomarkers of AD in subjects with early-onset AD (EOAD) without familial AD genetic mutations. Methods Patients with sporadic EOAD (sEOAD) were prospectively recruited by nine neurology clinics. Plasma levels of Aβ40 and Aβ42 were measured using a sandwich enzyme-linked immunosorbent assay (ELISA) in 100 sEOAD (50-69 year-old) and 46 age-matched normal control subjects (50-72 year-old). Cerebrospinal fluid (CSF) was obtained from 32 sEOAD subjects and 25 controls. The integrity of the blood-brain barrier was assessed using the CSF/plasma albumin ratio. Results The plasma levels of Aβ42 were significantly lower, while the Aβ40/Aβ42 ratio was significantly higher in sEOAD patients than in controls. The levels of Aβ40, Aβ42, and the Aβ40/Aβ42 ratio did not differ in relation to the APOEɛ4 allele. The CSF/plasma albumin ratio was comparable between the two groups, and the plasma parameters of Aβ proteins were not significantly associated. A multivariate analysis revealed that an increased Aβ40/Aβ42 ratio is valuable for the discrimination of sEOAD from controls (β=0.344, p=0.000). The area under the ROC curve for the Aβ40/Aβ42 ratio was 0.76, and a cut-off ratio of 5.87 was suggested to have 70% sensitivity and 68% specificity. Conclusion The plasma Aβ40/Aβ42 ratio had moderate validity for the discrimination of sEOAD patients from age-matched controls.

Background A relationship between body weight, cognitive impairment, and the onset of Alzheimer's disease (AD) was recently reported. However, to our knowledge, no studies have investigated the relationship between body weight and mortality in Asian AD patients. Objective We evaluated the relationship between body mass index (BMI) and mortality rate in Korean AD cohorts. Methods Participants were consecutively included from two Korean representative registries: 579 AD patients from Samsung Medical Center and 1911 AD patients from the Clinical Research Center for Dementia of South Korea study. We combined these two AD cohorts to evaluate the association between BMI and mortality. BMI was used to categorize the participants into underweight, normal-weight, overweight, and obesity subgroups. All deaths were confirmed through the nationwide mortality database of Statistics Korea. Results 53 of 181 (29.3%), 208 of 1,127 (18.5%), 88 of 626 (14.1%), and 115 of 556 (20.7%) patients died in the underweight, normal-weight, overweight, and obese subgroups during 43.7 months of follow-up. The time-dependent cox proportional hazards model showed that, relative to the normal-weight subgroup, the underweight group had higher mortality (HR 1.82 (95% CI, 1.07-3.09)) while overweight group had lower mortality rate (HR 0.60 (95% CI, 0.38-0.95)) The effects of underweight and overweight were prominent in younger and older elderly group, respectively. However, there were no interactive effects of dementia severity or gender and BMI on survival rate. Conclusion Relative to AD patients of normal weight, those who were underweight had an increased mortality rate, and overweight predicted decreased mortality in AD patients. Furthermore, our findings may help facilitate mortality stratification in AD patients by using baseline BMI.