Background: A decline in masticatory function may indicate brain dysfunction related to dementia, but the relationship between masticatory function and dementia risk remains unclear. This study aimed to investigate whether masticatory function is associated with the risk of cognitive decline and dementia. Methods: Data were obtained from the nationwide prospective cohort study of randomly sampled community-dwelling Koreans aged ≥ 60 years. The 5,064 non-demented participants, whose number of chewing cycles per bite was assessed by clinical interview, were followed for 8 years with biennial assessments of cognitive performance and clinical diagnoses of all-cause dementia and Alzheimer’s disease (AD). Structural brain magnetic resonance imaging was collected from a subset of cohort participants and their spouses for imaging analyses. Results: Males who chewed ≥ 30 cycles/bite had faster decline in global cognition and memory function and were at higher risk for incident all-cause dementia (hazard ratio [HR], 2.91; 95% confidence interval [CI], 1.18–7.18) and AD (HR, 3.22; 95% CI, 1.14–9.11) compared to males with less than 10 cycles/bite. Additionally, increased chewing cycles in males were associated with reduced brain volume, particularly in regions involved in compensatory cognitive control of mastication. There was no significant association between chewing cycles and the risk of dementia or brain volume in females. Conclusion Older men who frequently chew their meals could be considered a notable population at risk for dementia who should be carefully assessed for their cognitive trajectories.

Objective: The Scales for Outcomes in Parkinson’s Disease–Cognition (SCOPA-Cog) was developed to assess cognition in patients with Parkinson’s disease (PD). In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPACog (K-SCOPA-Cog). Methods: We enrolled 129 PD patients with movement disorders from 31 clinics in South Korea. The original version of the SCOPA-Cog was translated into Korean using the translation-retranslation method. The test–retest method with an intraclass correlation coefficient (ICC) and Cronbach’s alpha coefficient were used to assess reliability. Spearman’s rank correlation analysis with the Montreal Cognitive Assessment-Korean version (MOCA-K) and the Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. Results: The Cronbach’s alpha coefficient was 0.797, and the ICC was 0.887. Spearman’s rank correlation analysis revealed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). Conclusion Our results demonstrate that the K-SCOPA-Cog has good reliability and validity.

Objective: To investigate the relationship between reduced glutathione (GSH), a key molecule of the antioxidant defense system in the blood, and glutathione reductase (GR), which reduces oxidized glutathione (glutathione disulfide [GSSG]) to GSH and maintains the redox balance, with the prevalence of Alzheimer’s dementia and cognitive decline. Methods: In all, 20 participants with Alzheimer’s dementia who completed the third follow-up clinical evaluation over 6 years were selected, and 20 participants with normal cognition were selected after age and sex matching. The GSH and GR concentrations were the independent variables. Clinical diagnosis and neurocognitive test scores were the dependent variables indicating cognitive status. Results: The higher the level of GR, the greater the possibility of having normal cognition than of developing Alzheimer’s dementia. Additionally, the higher the level of GR, the higher the neurocognitive test scores. However, this association was not significant for GSH. After 6 years, the conversion rate from normal cognition to cognitive impairment was significantly higher in the lower 50th percentile of the GR group than in the upper 50th percentile. Conclusion The higher the GR, the lower the prevalence of Alzheimer’s dementia and incidence of cognitive impairment and the higher the cognitive test scores. Therefore, GR is a potential protective biomarker against Alzheimer’s dementia and cognitive decline.

Objective: Aneurysmal subarachnoid hemorrhage (SAH) is a common emergency condition, resulting in high morbidity and mortality. The delta neutrophil index (DNI), which reflects the fraction of circulating immature granulocytes, is significantly associated with systemic inflammation after infection or sterile injury. Aneurysmal SAH also leads to systemic inflammation after a brain injury. This study aimed to evaluate the relationship between the DNI and poor neurologic outcomes in patients with aneurysmal SAH. Methods: We retrospectively identified patients (>18 years old) with aneurysmal SAH consecutively admitted to the emergency department (ED) between January 1, 2011, and November 30, 2018. The diagnosis of aneurysmal SAH was confirmed using clinical and radiological findings. DNI was determined at 0, 24, 48, and 72 hours after ED admission. The primary result was a poor neurologic outcome using the modified Rankin scale. Results: A total of 352 patients with aneurysmal SAH were included in this study. A multivariable logistic regression model revealed that a high value of DNI at 24 hours after ED admission was a strong independent predictor of poor neurologic outcome upon discharge (odds ratio [OR], 1.471; 95% confidence interval [CI], 1.081-2.001; P=0.014). Among patients with aneurysmal SAH, DNI >1.0% at 24 hours was significantly associated with poor neurologic outcomes upon discharge (OR, 5.037; 95% CI, 3.153-8.044; P<0.001). Conclusion DNI can be determined easily and rapidly after ED admission without any additional cost or time burden. A high DNI value at 24 hours after ED admission is significantly associated with a poor neurologic outcome upon discharge among patients with aneurysmal SAH.