The Usefulness of 18 F-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 18 F-Fluorodeoxyglucose Positron Emission Tomography ( 18 F-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 18 F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the goldstandard 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@#18 F-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.

Lower-Body Fractures and the Risk of Dementia:A Nationwide Population-Based Study

Background@#and Purpose The association between physical activity and dementia has been shown in various observational studies. We aimed to determine the risk of dementia in the elderly with lower-body fractures. @*Methods@#We reconstructed a population-based matched cohort from the National Health Insurance Service—Senior Cohort data set that covers 511,953 recipients of medical insurance in South Korea. @*Results@#Overall 53,776 subjects with lower-body fractures were identified during 2006–2012, and triplicate control groups were matched randomly by sex, age, and years from the index date for each subject with a fracture. There were 3,573 subjects (6.6%) with and 7,987 subjects (4.9%) without lower-body fractures who developed dementia from 2008 up to 2015. Lowerbody fractures were independently associated with a subsequent dementia diagnosis with a higher adjusted hazard ratio (aHR) (1.55, 95% confidence interval [CI]=1.49–1.62) compared with upper-body fractures (aHR=1.19, 95% CI=1.14–1.23). @*Conclusions@#These results support the protective role of physical activity against dementia and highlight the importance of promoting fracture prevention in the elderly.

Influence of Sensory Impairments on Incidence of Dementia in the Korean Population

Objective@#Previous studies have shown the influence of visual and auditory sensory impairment on dementia incidence. In this study, we tested the hypothesis that the incidence of dementia will increase with visual and auditory impairments than with visual or auditory impairment. @*Methods@#Data from the Korea National Health Insurance Service database were used, including disease and medication codes from 2009 to 2018, and the 2011 national health check-up results. Participants were grouped based on their sensory abilities: normal, visual impairment, auditory impairment, and both visual and auditory impairments (dual sensory impairment). To compare the incidence of dementia, hazard ratios were calculated for each group, with reference to the normal sensory (NS) group. Sensitivity analyses were performed comparing dementia incidence from 2014 to 2018, excluding the onset of the disease in 2012 and 2013. @*Results@#We identified 8,289 cases of dementia during the seven-year follow-up. In the multiple Cox regression analysis, adjusted for sex, social economic status, age, comorbidities, smoking, alcohol consumption, and activity level, the auditory impairment (hazard ratio= 1.1908) and visual impairment (hazard ratio=1.3553) groups showed a significantly higher dementia incidence than the NS group. Dual sensory impairment (hazard ratio=1.5267) showed the highest incidence. The sensitivity analysis yielded similar results. @*Conclusion@#Visual and auditory impairments are associated with an increased risk of dementia, particularly in individuals with dual sensory impairment. Hence, visual and auditory impairments might have increased the risk of dementia through independent pathological processes. Therefore, preventing and correcting sensory impairment is necessary to reduce the risk of dementia.

Dementia Incidence Rate Before and After Implementing the National Responsibility Policy for Dementia Care in Patients With Vascular Risk Factors in Korea

Background@#and Purpose: The National Responsibility Policy for Dementia Care was implemented in September 2017 in Korea. This study aimed to compare dementia incidence in Seoul and Gangwon-do before and after the implementation of this policy. @*Methods@#We extracted insurance claim data from the Korean Health Insurance Review and Assessment Service for people diagnosed with diabetes, hypertension, or dyslipidemia for the first time in Seoul and Gangwon-do, Korea. We defined two enrollment groups based on the policy implementation date: 1) January 1, 2015 to December 31, 2016 (Index 1, pre-implementation), and 2) January 1, 2017 to December 31, 2018 (Index 2, postimplementation). Each group was followed up for 1 year from the time of enrollment. Then, we calculated hazard ratios to compare the incidence of dementia between the two groups, and between Seoul and Gangwon-do. @*Results@#In Seoul, the incidence of dementia was significantly lower in Index 2 than in Index 1 (hazard ratio [HR], 0.926; 95% confidence interval [CI], 0.875–0.979). However, the incidence rate did not differ between the 2 groups (HR, 1.113; 95% CI, 0.966–1.281) in Gangwon-do. In Index 1, the incidence of dementia did not differ between Seoul and Gangwon-do (HR, 1.043; 95% CI, 0.941–1.156), but in Index 2, was significantly higher in Gangwon-do than in Seoul (HR, 1.240; 95% CI, 1.109–1.386). @*Conclusions@#After implementing the National Responsibility Policy for Dementia Care, the dementia incidence rate decreased significantly in Seoul, consistent with other studies, but not in Gangwon-do.

Association of Nutritional Status with Cognitive Stage in the Elderly Korean Population: The Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease

BACKGROUND AND PURPOSE: Epidemiological studies have suggested the presence of strong correlations among diet, lifestyle, and dementia onset. However, these studies have unfortunately had major limitations due to their inability to fully control the various potential confounders affecting the nutritional status. The purpose of the current study was to determine the nutritional status of participants in the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease (KBASE) and to identify clinical risk factors for being at risk of malnutrition or being malnourished. METHODS: Baseline data from 212 participants [119 cognitively unimpaired (CU), 56 with mild cognitive impairment (MCI), and 37 with dementia] included in the KBASE database were analyzed. All participants underwent a comprehensive cognitive test and MRI at baseline. The presence of malnutrition at baseline was measured by the Mini Nutritional Assessment score. We examined the cross-sectional relationships of clinical findings with nutritional status using multiple logistic regression applied to variables for which p<0.2 in the univariate analysis. Differences in cortical thickness according to the nutritional status were also investigated. RESULTS: After adjustment for demographic, nutritional, and neuropsychological factors, participants with dementia had a significantly higher odds ratio (OR) for being at risk of malnutrition or being malnourished than CU participants [OR=5.98, 95% CI=1.20–32.97] whereas participants with MCI did not (OR=0.62, 95% CI=0.20–1.83). Cortical thinning in the at-risk/malnutrition group was observed in the left temporal area. CONCLUSIONS: Dementia was found to be an independent predictor for the risk of malnutrition compared with CU participants. Our findings further suggest that cortical thinning in left temporal regions is related to the nutritional status.

Pathologically Confirmed Cerebral Amyloid Angiopathy with No Radiological Sign in a Patient with Early Onset Alzheimer's Disease

Cerebral amyloid angiopathy (CAA) is associated with perivascular disruption, which is caused by progressive amyloid-beta (Aβ) deposition in vessels. Previous autopsy studies have shown that the prevalence of CAA in Alzheimer's disease (AD) is 70% to 90%. CAA is principally characterized by restricted lobar microbleeds (MBs), which can be detected by gradient-echo T2* (GRE) and susceptibility-weighted imaging (SWI). We herein report on a 62-year-old man who presented with 8 years of memory impairment. The apolipoprotein E (APOE) genotype was ε4/ε4, and a brain GRE performed 28 months before death revealed mild atrophy and no MBs. At autopsy, the patient scored “A3, B3, C3” according to the National Institute on Aging-Alzheimer's Association guidelines; the patient thus exhibited a high level of AD neuropathological changes. Furthermore, immunohistochemical staining for Aβ showed antibody accumulation and severe cerebral amyloid angiopathic changes in numerous vessels with amyloid deposits. Our case suggests that radiological CAA markers, such as cerebral microbleed (CMB) or cerebral superficial siderosis, may not suffice to detect amyloid angiopathy in cerebral vessels. CAA should therefore be considered as a combined pathology in APOE ε4 homozygotes with AD, even if such patients do not exhibit CMB on MRI.

The Brain Donation Program in South Korea

PURPOSE: Obtaining brain tissue is critical to definite diagnosis and to furthering understanding of neurodegenerative diseases. The present authors have maintained the National Neuropathology Reference and Diagnostic Laboratories for Dementia in South Korea since 2016. We have built a nationwide brain bank network and are collecting brain tissues from patients with neurodegenerative diseases. We are aiming to facilitate analyses of clinic-pathological and image-pathological correlations of neurodegenerative disease and to broaden understanding thereof. MATERIALS AND METHODS: We recruited participants through two routes: from memory clinics and the community. As a baseline evaluation, clinical interviews, a neurological examination, laboratory tests, neuropsychological tests, and MRI were undertaken. Some patients also underwent amyloid PET. RESULTS: We recruited 105 participants, 70 from clinics and 35 from the community. Among them, 11 died and were autopsied. The clinical diagnoses of the autopsied patients included four with Alzheimer's disease (AD), two with subcortical vascular dementia, two with non-fluent variant primary progressive aphasia, one with leukoencephalopathy, one with frontotemporal dementia (FTD), and one with Creutzfeldt-Jakob disease (CJD). Five patients underwent amyloid PET: two with AD, one with mixed dementia, one with FTD, and one with CJD. CONCLUSION: The clinical and neuropathological information to be obtained from this cohort in the future will provide a deeper understanding of the neuropathological mechanisms of cognitive impairment in Asia, especially Korea.

Proposal Guidelines for Standardized Operating Procedures of Brain Autopsy: Brain Bank in South Korea

To obtain an in-depth understanding of brain diseases, including neurodegenerative diseases, psychiatric illnesses, and neoplasms, scientific approach and verification using postmortem human brain tissue with or without disease are essential. Compared to other countries that have run brain banks for decades, South Korea has limited experience with brain banking; nationwide brain banks started only recently. The goal of this study is to provide provisional guidelines for brain autopsy for hospitals and institutes that have not accumulated sufficient expertise. We hope that these provisional guidelines will serve as a useful reference for pathologists and clinicians who are involved and interested in the brain bank system. Also, we anticipate updating the provisional guidelines in the future based on collected data and further experience with the practice of brain autopsy in South Korea.

A Case of Squamous Cell Lung Cancer Representing as Guillain-Barre Syndrome Associated with Monospecific Anti-GD1b IgG / 대한임상신경생리학회지

We report a case with squamous cell lung cancer with concomitant Guillain-Barre syndrome (GBS) as a paraneoplastic syndrome. A 67-year-old patient who was previously diagnosed as metastatic squamous cell lung cancer developed mild symmetrical weakness, paresthesia and sensory ataxia. Nerve conduction study showed sensorimotor polyneuropathy. Analysis of cerebrospinal fluid showed high tilter for monospecific anti-GD1b IgG antibody without onconeuronal antibodies. After treatment with intravenous immunoglobulin, the patient's symptoms improved.

A case of Ophthalmic Zoster Presenting as Multiple Cranial Nerve Palsies, Ultimately Leading to Death

No abstract available.