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.

Cognitive impairment evaluated with Vascular Cognitive Impairment Harmonization Standards in a multicenter prospective stroke cohort in Korea.

BACKGROUND AND PURPOSE: Since the Vascular Cognitive Impairment Harmonization Standards (VCIHS) neuropsychological test protocol was proposed by the National Institute of Neurological Disorders and Stroke and Canadian Stroke Network, no studies have applied this neuropsychological protocol to poststroke survivors in a large-scale, multicenter stroke cohort. We determined the frequency of vascular cognitive impairment (VCI) and investigated the feasibility of using the Korean version of the VCIHS neuropsychological protocol in a multicenter, hospital-based stroke cohort in Korea. METHODS: We prospectively enrolled 620 subjects with ischemic stroke within 7 days of symptom onset among 899 patients who were consecutively admitted to 12 university hospitals in Korea. Neuropsychological assessments using the 60-minute Korean VCIHS neuropsychological protocol were administered at 3 months after stroke. RESULTS: Of the 620 patients, 506 were followed up at 3 months after stroke. Of these, 353 (69.8%) were evaluated for cognitive function using the 60-minute Korean VCIHS neuropsychological protocol. The frequency of VCI at 3 months was 62.6%: VCI with no dementia in 49.9% and vascular dementia in 12.7%. Old age (P=0.014), poor functional outcomes at 3 months (P=0.029), and stroke subtypes other than small vessel disease (P=0.004) were independent risk factors of VCI. CONCLUSIONS: VCI, evaluated using the Korean VCIHS neuropsychological protocol, is substantial at 3 months after ischemic stroke in Korea. The use of the 60-minute Korean VCIHS neuropsychological protocol was feasible in large-scale multicenter studies.

Validity and reliability of a korean version of the national institutes of health stroke scale.

BACKGROUND AND PURPOSE: The National Institutes of Health Stroke Scale (NIHSS) is a clinical assessment tool that is widely used in clinical trials and practice to evaluate stroke-related neurological deficits. The aim of this study was to determine the validity and reliability of the Korean version of the NIHSS (K-NIHSS) for evaluating Korean stroke patients. METHODS: The K-NIHSS was translated and adapted with regard to cultural and linguistic peculiarities. To examine its content validity, we quantified the Content Validity Index (CVI), which was rated by 11 stroke experts. The validity of the K-NIHSS was assessed by comparison with the Glasgow Coma Scale (GCS), the modified Rankin Scale (mRS), and the Barthel Index. The reliability of the K-NIHSS was evaluated using the unweighted kappa statistics for multiple raters and an intraclass correlation coefficient (ICC). RESULTS: The CVI of the K-NIHSS reached 0.91-1.00. The median K-NIHSS score at baseline was 3 (interquartile range, 2-7), and the mean±SD score was 6.0±6.6. The baseline K-NIHSS had a significantly negative correlation with the GCS at baseline and the Barthel Index after 90 days. The K-NIHSS also had a significantly positive correlation with the mRS after 90 days. Facial paresis and dysarthria had moderate interrater reliability (unweighted kappa, 0.41-0.60); kappa values were substantial to excellent (unweighted kappa, >0.60) for all the other items. The ICC for the overall K-NIHSS score was 0.998. The intrarater reliability was acceptable, with a median kappa range of 0.524-1.000. CONCLUSIONS: The K-NIHSS is a valid and reliable tool for assessing neurological deficits in Korean acute stroke patients.

Response to rivastigmine transdermal patch or memantine plus rivastigmine patch is affected by apolipoprotein E genotype in Alzheimer patients.

BACKGROUND/AIMS: The apolipoprotein E (APOE) genotype in response to pharmacological treatments in patients with Alzheimer's disease (AD) remains a matter of controversy. This analysis investigated the effect of the APOE genotype on the clinical response to rivastigmine transdermal patch monotherapy or memantine plus rivastigmine patch in patients with mild to moderate AD. METHODS: Two hundred and six (n = 206) patients with probable AD and Mini-Mental State Examination (MMSE) scores of 10-20 were randomized to rivastigmine patch monotherapy or memantine plus rivastigmine patch for 24 weeks. Of the 206 patients with probable AD, 146 patients who consented to genetic testing for APOE were included and assessed for this subgroup study. RESULTS: There were no significant differences on MMSE, NPI, ADAS-cog, ADCS-ADL, CDR-SB, NPI and FAB between rivastigmine patch monotherapy and memantine plus rivastigmine patch according to the APOE genotype. However, patients with moderately severe AD (MMSE ≤15) who were APOE ε4 carriers showed higher responder rates on ADCS-ADL with memantine plus rivastigmine patch compared to rivastigmine patch monotherapy. CONCLUSION: Moderately severe AD patients with the APOE ε4 allele may respond more favorably to memantine plus rivastigmine patch than ε4 noncarriers.

Symptomatic hemorrhagic transformation and its predictors in acute ischemic stroke with atrial fibrillation.

BACKGROUND AND PURPOSE: Patients with acute cardioembolic stroke frequently show hemorrhagic transformation (HTr). We attempted to identify predictors of symptomatic HTr in acute ischemic stroke with atrial fibrillation (AF). METHODS: Of the consecutive acute ischemic stroke patients with AF at 12 hospitals in Korea, patients with posterior circulation stroke or thrombolytic therapy were excluded. Immediate anticoagulation was recommended to all patients, except those with: (1) large infarcts, 50% or more of the middle cerebral artery territory, (2) significant HTr on initial imaging, or (3) other safety concerns. Symptomatic HTr was defined as cerebral hemorrhage temporally related to neurological deterioration. RESULTS: Of the 389 included patients (mean age 71 years), 260 (67%) were treated with anticoagulation within 1 week from the onset. Symptomatic HTr occurred in 4.6%. Large infarct (OR 6.38, 95% CI 1.16-35.14), previous hemorrhagic stroke (OR 10.67, 1.77-64.25), and low platelet count (OR per 10(4) increase 0.87, 0.79-0.97) were independent predictors of symptomatic HTr. hsCRP values tended to be higher in patients with symptomatic HTr (p = 0.055). CONCLUSIONS: Caution is needed in anticoagulation treatment of acute cardioembolic stroke patients with a large infarct, previous hemorrhagic stroke, low platelet count, or a high hsCRP level.