Assessing the Impact of Defacing Algorithms on Brain Volumetry Accuracy in MRI Analyses.

Background and Purpose: To ensure data privacy, the development of defacing processes, which anonymize brain images by obscuring facial features, is crucial. However, the impact of these defacing methods on brain imaging analysis poses significant concern. This study aimed to evaluate the reliability of three different defacing methods in automated brain volumetry. Methods: Magnetic resonance imaging with three-dimensional T1 sequences was performed on ten patients diagnosed with subjective cognitive decline. Defacing was executed using mri_deface, BioImage Suite Web-based defacing, and Defacer. Brain volumes were measured employing the QBraVo program and FreeSurfer, assessing intraclass correlation coefficient (ICC) and the mean differences in brain volume measurements between the original and defaced images. Results: The mean age of the patients was 71.10±6.17 years, with 4 (40.0%) being male. The total intracranial volume, total brain volume, and ventricle volume exhibited high ICCs across the three defacing methods and 2 volumetry analyses. All regional brain volumes showed high ICCs with all three defacing methods. Despite variations among some brain regions, no significant mean differences in regional brain volume were observed between the original and defaced images across all regions. Conclusions: The three defacing algorithms evaluated did not significantly affect the results of image analysis for the entire brain or specific cerebral regions. These findings suggest that these algorithms can serve as robust methods for defacing in neuroimaging analysis, thereby supporting data anonymization without compromising the integrity of brain volume measurements.

Cortex-to-caudate volume ratio as a predictor of cognitive decline in Alzheimer's disease and mild cognitive impairment.

BACKGROUND: Brain and cortical atrophy play crucial roles in supporting the clinical diagnosis of Alzheimer's disease (AD). This study hypothesized that the ratios of brain or cortical volume to subcortical gray matter structure volumes are potential imaging markers for cognitive alterations in AD dementia and amnestic mild cognitive impairment (aMCI). METHODS: Seventy-seven subjects diagnosed with AD dementia or aMCI underwent baseline neuropsychological testing, 2-year follow-up cognitive assessments, and high-resolution T1-weighted MRI scans. Total brain/cortical volume and subcortical gray matter structure volumes were automatically segmented and measured. Univariate and multiple linear regression analyses were conducted to determine the associations between volumetric ratios and interval changes in cognitive scores. RESULTS: The ratio of cortical volume to caudate volume showed the most significant association with changes in MoCA (B = 0.132, SE = 0.042, p = 0.002), MMSE (B = 0.140, SE = 0.040, p = 0.001), and CDR-SOB (B = -0.013, SE = 0.005, p = 0.007) scores over the 2-year follow-up period. These associations remained significant after adjusting for various covariates. Similar associations were observed for the ratios of cortical volume to putamen and globus pallidum volumes. CONCLUSIONS: The cortex-to-caudate volume ratio is significantly associated with cognitive decline in AD dementia and aMCI. This ratio may serve as a useful biomarker for monitoring disease progression and predicting cognitive outcomes. Our findings highlight the importance of considering the relative atrophy of cortical and subcortical structures in understanding AD pathology.

A Phase II Study About Efficacy and Safety of the Continuous IntraVenous Infusion of Ketamine as Adjuvant to Opioids in Terminally Ill Cancer Patients With Refractory Cancer Pain (CIVIK Trial).

BACKGROUND: Ketamine has been used to control refractory cancer pain as an adjuvant to opioids. We conducted a prospective phase II study to investigate the efficacy and safety of 5-day continuous intravenous infusion (CIVI) of Ketamine in terminally ill cancer patients with refractory cancer pain. METHODS: Hospitalized terminally ill cancer patients with refractory cancer pain were enrolled. Refractory cancer pain was indicated by requirements for 4 or more rescue opioids or pain intensity using numerical rating scale > personalized pain goal (PPG) despite of intravenous morphine equivalent daily dose (IV MEDD) ≥ 120 mg/day. The CIVI of ketamine was increased from .05 mg/kg/hour to .5 mg/kg/hour by .05 every 8 hours if pain intensity exceeded PPG or if number of rescue opioids ≥2 during prior 8 hours was required. The primary end-point was overall pain response rate, which indicates complete response (both rescue opioid ≤3/day and pain intensity ≤ PPG) plus partial response (rescue opioid ≤3/day), without unacceptable toxicities. RESULTS: Among 21 eligible patients enrolled between September 2019 and January 2023, 20 were analyzed. Most pain mechanisms were mixed type (n = 15, 75%), with neuropathic component (n = 17, 85%). The baseline background opioids were IV MEDD 186 mg/24hour (range, 124-592), number of rescue opioids was 6 (IQR, 5-9), and median PPG was 4 (IQR, 3-4). The overall pain response rate was 50% (n = 10) including 40% (n = 8) for complete pain response and 10% (n = 2) for partial pain response. CONCLUSION: This study showed efficacy of gradually increasing CIVI of ketamine for terminally ill cancer patients with refractory cancer pain. CIVI of ketamine could be a useful tool in these patients considering the limited treatment options. (NCT03362073, Initial Release: November 15, 2017).

The incidence and predictors of antibiotic-associated encephalopathy: a multicenter hospital-based study.

This study aimed to evaluate the incidence and likelihood of antibiotic-associated encephalopathy (AAE), comparing rates among the classes of antibiotics in monotherapy or in combination therapy. We also investigated the associations between the incidence of AAE and the glomerular filtration rate (GFR) and electroencephalogram features. Consecutive admissions that used any kind of antibiotics to treat infectious diseases were identified from six hospitals. We classified antibiotics according to three distinct pathophysiologic mechanisms and clinical subtypes. We searched for the incidence of AAE as the primary outcome. A total of 97,433 admission cases among 56,038 patients was identified. Cases that received type 1 antibiotics had significantly more frequent AAE compared to those that received type 2 antibiotics (adjusted odds ratio [OR], 2.62; 95% confidence interval [CI] 1.15-5.95; P = 0.021). Combined use of type 1 + 2 antibiotics was associated with a significantly higher incidence of AAE compared to the use of type 2 antibiotics alone (adjusted OR, 3.44; 95% CI 1.49-7.93; P = 0.004). Groups with GFR < 60 mL/min/1.73 m2 had significantly higher incidence rates of AAE compared to those with GFRs ≥ 90 mL/min/1.73 m2 among cases that received type 1 + 2 antibiotics. Detection of spike-and-wave or sharp-and-wave patterns on electroencephalogram was significantly more common in the combination therapy group. Combination use of antibiotics was associated with a higher incidence of AAE compared to monotherapy. The incidence of AAE significantly increased as renal function decreased, and epileptiform discharges were more likely to be detected in cases receiving combined antibiotics.

Feasibility and usefulness of cognitive monitoring using a new home-based cognitive test in mild cognitive impairment: a prospective single arm study.

BACKGROUND: The risk of dementia is increased in subjects with mild cognitive impairment (MCI). Despite the plethora of in-person cognitive tests, those that can be administered over the phone are lacking. We hypothesized that a home-based cognitive test (HCT) using phone calls would be feasible and useful in non-demented elderly. We aimed to assess feasibility and validity of a new HCT as an optional cognitive monitoring tool without visiting hospitals. METHODS: Our study was conducted in a prospective design during 24 weeks. We developed a new HCT consisting of 20 questions (score range 0-30). Participants with MCI (n = 38) were consecutively enrolled and underwent regular HCTs during 24 weeks. Associations between HCT scores and in-person cognitive scores and Alzheimer's disease (AD) biomarkers were evaluated. In addition, HCT scores in MCI participants were cross-sectionally compared with age-matched cognitively normal (n = 30) and mild AD dementia (n = 17) participants for discriminative ability of the HCT. RESULTS: HCT had good intra-class reliability (test-retest Cronbach's alpha 0.839). HCT scores were correlated with the Mini-Mental State Examination (MMSE), verbal memory delayed recall, and Stroop test scores but not associated with AD biomarkers. HCT scores significantly differed among cognitively normal, MCI, and mild dementia participants, indicating its discriminative ability. Finally, 32 MCI participants completed follow-up evaluations, and 8 progressed to dementia. Baseline HCT scores in dementia progressors were lower than those in non-progressors (p = 0.001). CONCLUSION: The feasibility and usefulness of the HCT were demonstrated in elderly subjects with MCI. HCT could be an alternative option to monitor cognitive decline in early stages without dementia.

The Usefulness of 18F-FDG PET to Differentiate Subtypes of Dementia: The Systematic Review and Meta-Analysis.

Background and Purpose: Dementia subtypes, including Alzheimer's dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the gold-standard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88-0.98) and specificity was 0.84 (95% CI, 0.70-0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70-0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80-0.91) and the specificity was 0.88 (95% CI, 0.80-0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions: 18F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

Relationship Between Amyloid Positivity and Sleep Characteristics in the Elderly With Subjective Cognitive Decline.

Background and Purpose: Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive decline in cognition and performance of daily activities. Recent studies have attempted to establish the relationship between AD and sleep. It is believed that patients with AD pathology show altered sleep characteristics years before clinical symptoms appear. This study evaluated the differences in sleep characteristics between cognitively asymptomatic patients with and without some amyloid burden. Methods: Sleep characteristics of 76 subjects aged 60 years or older who were diagnosed with subjective cognitive decline (SCD) but not mild cognitive impairment (MCI) or AD were measured using Fitbit® Alta HR, a wristwatch-shaped wearable device. Amyloid deposition was evaluated using brain amyloid plaque load (BAPL) and global standardized uptake value ratio (SUVR) from fluorine-18 florbetaben positron emission tomography. Each component of measured sleep characteristics was analyzed for statistically significant differences between the amyloid-positive group and the amyloid-negative group. Results: Of the 76 subjects included in this study, 49 (64.5%) were female. The average age of the subjects was 70.72±6.09 years when the study started. 15 subjects were classified as amyloid-positive based on BAPL. The average global SUVR was 1.598±0.263 in the amyloid-positive group and 1.187±0.100 in the amyloid-negative group. Time spent in slow-wave sleep (SWS) was significantly lower in the amyloid-positive group (39.4±13.1 minutes) than in the amyloid-negative group (49.5±13.1 minutes) (p=0.009). Conclusions: This study showed that SWS is different between the elderly SCD population with and without amyloid positivity. How SWS affects AD pathology requires further research.

A Longitudinal Study on Memory Enhancement in Subjective Cognitive Decline Patients: Clinical and Neuroimaging Perspectives.

BACKGROUND: Subjective cognitive decline (SCD) refers to the self-reported persistent cognitive decline despite normal objective testing, increasing the risk of dementia compared to cognitively normal individuals. OBJECTIVE: This study aims to investigate the attributes of SCD patients who demonstrated memory function improvement. METHODS: In this prospective study of SCD, a total of 120 subjects were enrolled as part of a multicenter cohort study aimed at identifying predictors for the clinical progression to mild cognitive impairment or dementia (CoSCo study). All subjects underwent 18F-florbetaben PET and brain MRI scans at baseline and annual neuropsychological tests. At the 24-month follow-up, we classified SCD patients based on changes in memory function, the z-score of the Seoul verbal learning test delayed recall. RESULTS: Of the 120 enrolled patients, 107 successfully completed the 24-month follow-up assessment. Among these, 80 patients (74.8%) with SCD exhibited memory function improvements. SCD patients with improved memory function had a lower prevalence of coronary artery disease at baseline and performed better in the trail-making test part B compared to those without improvement. Anatomical and biomarker analysis showed a lower frequency of amyloid PET positivity and larger volumes in the left and right superior parietal lobes in subjects with improved memory function. CONCLUSIONS: Our prospective study indicates that SCD patients experiencing memory improvement over a 24-month period had a lower amyloid burden, fewer cardiovascular risk factors, and superior executive cognitive function. Identifying these key factors associated with cognitive improvement may assist clinicians in predicting future memory function improvements in SCD patients.

Impacts of baseline biomarkers on cognitive trajectories in subjective cognitive decline: the CoSCo prospective cohort study.

BACKGROUND: Subjective cognitive decline (SCD) is a risk factor for Alzheimer's disease (AD); however, the rates of cognitive decline are variable according to underlying pathologies and biomarker status. We conducted an observational study and aimed to investigate baseline characteristics and biomarkers related with cognitive declines in SCD. Our study also assessed whether SCD participants showed different cognitive and biomarker trajectories according to baseline amyloid deposition. METHODS: This study is a part of a longitudinal cohort study conducted in multi-centers in South Korea between 2018 and 2021. Individuals (≥ 60 years old) with persistent cognitive complaint despite of normal cognitive functions were eligible for the study. All participants underwent neuropsychological tests, florbetaben PET scans, plasma amyloid markers, and brain MRI scans. Annual follow-up evaluations included neuropsychological tests and assessments for clinical progressions. Regional brain volumetry and amyloid burden represented by PET-based standardized uptake value ratio (SUVR) were measured. We compared cognitive and brain atrophic changes over 24 months between amyloid positive-SCD (Aß + SCD) and amyloid negative-SCD (Aß-SCD) groups. Baseline factors associated with cognitive outcomes were investigated. RESULTS: A total of 120 participants with SCD were enrolled and 107 completed follow-up evaluations. Aß + SCD participants (n = 20, 18.5%) were older and more frequently APOE4 carriers compared with Aß-SCD participants (n = 87). Baseline cognitive scores were not different between the two groups, except the Seoul Verbal Learning Test (SVLT) scores showing lower scores in the Aß + SCD group. After 24 months, plasma amyloid markers were higher, and regional volumes (entorhinal, hippocampal, and pallidum) were smaller in the Aß + SCD participants compared with Aß-SCD participants adjusted by age, sex, and baseline volumes. SVLT delayed recall and controlled oral word association test (COWAT) scores indicated more declines in Aß + SCD participants. Baseline left entorhinal volumes were related to verbal memory decline, while baseline frontal volumes and global SUVR values were related to frontal functional decline. CONCLUSION: Aß + SCD participants showed more cognitive decline and medial temporal atrophic changes during 24 months. Baseline neurodegeneration and amyloid burden were related with future cognitive trajectories in SCD. TRIAL REGISTRATION: This study was registered at CRIS (KCT0003397).

Phase II study of neoadjuvant chemotherapy with four cycles of dose-dense MVAC followed by radical cystectomy in Korean patients with muscle-invasive or locally advanced urothelial carcinoma of bladder.

PURPOSE: While previous retrospective or phase II studies in Western populations showed that dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC) as neoadjuvant chemotherapy (NAC) was beneficial, no studies have been reported in Asian populations. This prospective phase II study aimed to evaluate efficacy and safety of ddMVAC in Korean patients with muscle-invasive bladder cancer (MIBC) or locally advanced urothelial cancer (UC). MATERIALS AND METHODS: Patients with MIBC (cT2-4aN0M0) or locally advanced UC (cTanyN1-3M0) eligible for radical cystectomy (RC) were enrolled prospectively. The participants were treated with four cycles of ddMVAC with pegfilgrastim every 2 weeks. The primary endpoint was pathologic response rate (≤ypT1N0). Secondary endpoints were pathologic complete response (pCR, ypT0N0), relapse-free survival (RFS), overall survival (OS), and safety. RESULTS: Among 24 patients enrolled between December 2019 and August 2021, 23 were evaluable (52%, cT2-4aN0; 48%, cTanyN1-3). Eighteen patients (78%) completed four cycles of ddMVAC, while remaining five patients experienced early discontinuation. Dose modification (91%) and dose delay (70%) occurred, and the dose intensity of ddMVAC was 79%. Nineteen patients underwent RC and four patients declined. Of 19 patients who underwent RC, eight patients (42%) achieved ≤ypT1N0. With a median follow-up of 22.8 months, the median RFS was 13.5 months (95% CI, not yet evaluable) and the median OS was 28.9 months (95% confidence interval, 19.9-37.9). CONCLUSION: Our study showed substantial efficacy and safety of ddMVAC, even in patients with locally advanced UC. The ddMVAC still should be a promising option as NAC in Asian patients with UC.

Risk of epilepsy in gonadal teratoma: a nationwide population-based study.

Epilepsy is a common neurological disease. Systemic tumors are associated with an increased risk of epileptic events. Paraneoplastic encephalitis related to gonadal teratoma is frequently accompanied by seizures and life-threatening status epilepticus (SE). However, the risk of epilepsy in gonadal teratoma has not been studied. This study aims to investigate the relationship between epileptic events and gonadal teratoma. This retrospective cohort study used the Korean National Health Insurance (KNHI) database. The study population was divided into two study arms (ovarian teratoma vs. control and testicular teratoma vs. control) with 1:2 age and gender-matched control groups without a history of gonadal teratoma or other malignancy. Participants with other malignancies, neurologic disorders, and metastatic brain lesions were excluded. We observed the occurrence of epileptic events during the observation period (2013-2018) and investigated the risk of epileptic events in each gonadal teratoma group compared to controls. In addition, the influence of malignancy and tumor removal was investigated. The final analysis included 94,203 women with ovarian teratoma, 2314 men with testicular teratoma, and controls. Ovarian teratoma is associated with a higher risk of epilepsy without SE (HR, 1.244; 95% CI 1.112-1.391) and epilepsy with SE (HR, 2.012; 95% CI 1.220-3.318) compared to the control group. The risk of epilepsy without SE was higher in malignant ovarian teratoma (HR, 1.661; 95% CI 1.358-2.033) than in benign (HR, 1.172; 95% CI 1.037-1.324). Testicular teratoma did not show significant relations with epileptic events. The risk of epileptic events showed a tendency to decrease after removing the ovarian teratoma. This study found that ovarian teratoma is associated with a higher risk of epileptic events, especially in malignant tumors, whereas testicular teratoma did not show significant differences in epileptic events compared to the control group. This study adds to the current understanding of the association between gonadal teratoma and epileptic events.

Clinical Significance of Physical Frailty in Subjects With Subjective Cognitive Decline: A Prospective Study With Amyloid PET Data.

BACKGROUND AND PURPOSE: Physical frailty is known to be closely associated with cognitive impairment and to be an early sign of Alzheimer's disease. We aimed to understand the characteristics of physical frailty and define factors associated with physical frailty in subjects with subjective cognitive decline (SCD) by analyzing amyloid data. METHODS: We prospectively enrolled subjects with SCD from a cohort study to identify predictors for the clinical progression to mild cognitive impairment or dementia from SCD (CoSCo). All of the subjects underwent brain magnetic resonance imaging, and brain amyloid positron-emission tomography (PET) to detect amyloid beta plaques. Self-reported exhaustion, handgrip strength, and gait speed were used to measure physical frailty. RESULTS: Of 120 subjects with SCD, 26 (21.7%) were amyloid-positive in PET. Female (odds ratio [OR]=3.79, p=0.002) and amyloid-PET-positive (OR=3.80, p=0.008) subjects with SCD were at high risks of self-reported exhaustion. Amyloid PET positivity (OR=3.22, p=0.047) and high burden from periventricular white-matter hyperintensity (OR=3.34, 95% confidence interval=1.18-9.46, p=0.023) were significantly associated with a weaker handgrip. The subjects with SCD with self-reported exhaustion and weaker handgrip presented with lower cognitive performance in neuropsychological tests, especially for information processing speed and executive function. Subjects with a slower gait performed worse in visual memory function tests. CONCLUSIONS: Amyloid PET positivity was associated with a higher risk of self-reported exhaustion and weaker handgrip in subjects with SCD. The subjects with SCD and physical frailty also performed worse in neuropsychological tests.

Comparison of prophylactic effects for chemotherapy induced neutropenia between same-day versus next-day administration of pegteograstim (Neurapeg®) in patients treated with chemotherapy regimen composed of day 1 intensive myleosuppressive agent: A randomized phase III clinical trial.

BACKGROUND AND PURPOSE: Administration of pegylated granulocyte-colony-stimulating factor (peg-GCSF) 24 to 72 hours after chemotherapy is usually recommended. Next-day administration (after 24 hours) resulted in fewer duration of grade (Gr) 4 chemotherapy-induced neutropenia (CIN) and decreased severity of CIN than same-day (within 4 hours). However, patients sometimes receive same-day Peg-GCSF for the sake of convenience. In addition, a few prior studies showed that the same-day method is comparable or superior to the next-day method in preventing CIN, especially in chemotherapy regimens that include day 1 myelosuppressive agents. Thus, we aim to verify the hypothesis that same-day administration of pegteograstim, a new formulation of peg-GCSF, is non-inferior to next-day administration in terms of Gr4 CIN duration. METHODS: This study is a randomized, multicenter, open-label, investigator-initiated phase 3 study. Patients with adjuvant/neoadjuvant or first-line palliative chemotherapy comprising intensively myelosuppressive agents on day 1 (mFOLFIRINOX, ECb, EP, FOLFIRI, and FOLFOX) are enrolled. The patients are assigned to the same-day arm or the next-day arm in a 1:1 ratio. The randomizations are stratified according to number of patient CIN risk factors (1 vs ≥2), chemotherapy setting (perioperative vs palliative), and interval (2-week vs 3-week). In the same-day arm, pegteograstim 6 mg is subcutaneously injected within 4 hours after completion of chemotherapy. In the next-day arm, pegetograstim is injected at 24 to 36 hours post-chemotherapy. A complete blood count test is performed daily from day 5 to 9 during the cycle 1. The primary endpoint is duration of Gr4 CIN (cycle 1), and secondary endpoints include incidence of Gr 3 to 4 CIN (cycle 1), severity of CIN (cycle 1), time to recovery absolute neutrophil count 1000/µL (cycle 1), incidence of febrile neutropenia, incidence of CIN-related dose delay, and dose intensity. In order to verify non-inferiority of 0.6 days, we estimated a significance level of 5%, power of 80%, and drop-out rate of 15%. This results in the need for a total of 160 patients, 80 in each group.

Development of a home-based cognitive test for cognitive monitoring in subjective cognitive decline with high risk of Alzheimer's disease.

BACKGROUND AND PURPOSE: Subjective cognitive decline (SCD) indicates a self-perceived persistent cognitive worsening despite of normal performance in standard neuropsychological tests. Owing to its heterogeneity and potential risk of Alzheimer's disease, baseline biomarkers to predict cognitive decline are important. In the present study, we developed a home-based cognitive test (HCT) to monitor cognitive changes regularly without visiting hospitals. This study aims to compare cognitive and biomarker trajectories during a 48-month period between amyloid positive SCD and amyloid negative SCD subjects. METHODS: Data will be collected from a prospective observational cohort study conducted in South Korea. Eighty participants with SCD aged ≥ 60 years are eligible for the study. All participants undergo annual neuropsychological tests and neurological examinations, bi-annual brain MRI scans and plasma amyloid markers, and baseline florbetaben Positron Emission Tomography scans. The amyloid burden and regional volumes will be measured. Cognitive and biomarker changes will be compared between the amyloid-positive SCD and amyloid negative SCD groups. Validation would be performed to assess reliability and feasibility of HCT. CONCLUSIONS: This study would suggest a perspective on SCD in terms of cognitive and biomarker trajectories. Baseline characteristics and biomarker status might affect faster cognitive decline and future biomarker trajectories. In addition, HCT could be an alternative option of in-person neuropsychological tests to track cognitive changes without visiting hospitals.

Study Design and Baseline Results in a Cohort Study to Identify Predictors for the Clinical Progression to Mild Cognitive Impairment or Dementia From Subjective Cognitive Decline (CoSCo) Study.

Background and Purpose: 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. Methods: 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 χ2 test or Fisher's exact test. Logistic regression models were used to assess the predictors of amyloid positivity. Results: The 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. Conclusions: 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.

Electroencephalography for Early Detection of Alzheimer's Disease in Subjective Cognitive Decline.

Background and Purpose: 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. Methods: Participants with SCD from 6 dementia clinics in Korea were enrolled. 18F-florbetaben brain amyloid positron emission tomography (PET) was conducted for all the participants. qEEG was performed to measure power spectrum and source cortical activity. Results: 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 (p=0.025), parietal (p=0.005), and occipital (p=0.022) areas even after adjusting for age, sex, and education. Source activities of alpha 1 band were significantly decreased in the bilateral fusiform and inferior temporal areas, whereas those of delta band were increased in the bilateral cuneus, pericalcarine, lingual, lateral occipital, precuneus, posterior cingulate, and isthmus areas. There were increased connections between bilateral precuneus areas but decreased connections between left rostral middle frontal area and bilateral frontal poles at delta band in participants with amyloid PET (+) showed. At alpha 1 band, there were decreased connections between bilateral entorhinal areas after adjusting for covariates. Conclusions: 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.

The Effect of Hearing Loss on Cognitive Function in Subjective Cognitive Decline.

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.

Correlations between APOE4 allele and regional amyloid and tau burdens in cognitively normal older individuals.

The correlations between apolipoprotein epsilon 4 (APOE4) status and regional amyloid, tau, and cortical thickness in cognitively normal elderly are not fully understood. Our cross-sectional study aimed to compare regional amyloid/tau burden, and cortical thickness according to APOE4 carrier status and assess correlations between APOE4 and Alzheimer's disease (AD)-related biomarker burdens. We analyzed 185 cognitively normal participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. Participants aged 55-90 with normal cognitive function were divided into amyloid ß-positive (Aß+) APOE4 carriers (group 1, n = 27), Aß+ APOE4 non-carriers (group 2, n = 29), and Aß- normal controls (group 0, n = 129). We compared amyloid depositions, tau depositions, and cortical thickness among the three groups and assessed correlations between APOE4 existence and imaging biomarkers adjusted for age and sex. The participants in group 2 were older than those in the other groups. The regional amyloid/tau standardized uptake value ratios (SUVRs) did not differ between groups 1 and 2, but the amyloid/tau SUVRs in most regions were numerically higher after adjusting for age difference. APOE4 allele had robust correlations with increased amyloid burden in the fronto-temporo-parietal cortical areas after adjustment for age and sex, but it had weaker and mixed correlations with the regional tau burden and did not have significant correlation with cortical thickness. We identified that the presence of APOE4 allele might be more highly associated with amyloid deposition than with other AD-related biomarkers such as tau or cortical thickness in cognitively normal elderly.

Automated brain volumetric program measuring regional brain atrophy in diagnosis of mild cognitive impairment and Alzheimer's disease dementia.

A quantitative analysis of brain volume can assist in the diagnosis of Alzheimer's disease (AD) which is ususally accompanied by brain atrophy. With an automated analysis program Quick Brain Volumetry (QBraVo) developed for volumetric measurements, we measured regional volumes and ratios to evaluate their performance in discriminating AD dementia (ADD) and mild cognitive impairment (MCI) patients from normal controls (NC). Validation of QBraVo was based on intra-rater and inter-rater reliability with a manual measurement. The regional volumes and ratios to total intracranial volume (TIV) and to total brain volume (TBV) or total cerebrospinal fluid volume (TCV) were compared among subjects. The regional volume to total cerebellar volume ratio named Standardized Atrophy Volume Ratio (SAVR) was calculated to compare brain atrophy. Diagnostic performances to distinguish among NC, MCI, and ADD were compared between MMSE, SAVR, and the predictive model. In total, 56 NCs, 44 MCI, and 45 ADD patients were enrolled. The average run time of QBraVo was 5 min 36 seconds. Intra-rater reliability was 0.999. Inter-rater reliability was high for TBV, TCV, and TIV (R = 0.97, 0.89 and 0.93, respectively). The medial temporal SAVR showed the highest performance for discriminating ADD from NC (AUC = 0.808, diagnostic accuracy = 80.2%). The predictive model using both MMSE and medial temporal SAVR improved the diagnostic performance for MCI in NC (AUC = 0.844, diagnostic accuracy = 79%). Our results demonstrated QBraVo is a fast and accurate method to measure brain volume. The regional volume calculated as SAVR could help to diagnose ADD and MCI and increase diagnostic accuracy for MCI.