Socioeconomic and medical determinants of state-level subjective cognitive decline in the United States.

INTRODUCTION: It is important to understand the socioeconomic and medical determinants of subjective cognitive decline (SCD) at a population level in the United States. METHODS: The primary outcomes are state-level rates of SCD and SCD-related functional impairment in adults aged ≥ 45, both measured in the Behavioral Risk Factor Surveillance System from 2016 to 2022. The exposures are state-level rates of poverty, unemployment, homelessness, college education, racial and ethnic minorities, uninsurance, smoking, hypertension, diabetes, and obesity as well as household income and physician density. RESULTS: The strongest state-level associations with rates of SCD were the prevalence of diabetes (rho = 0.64), hypertension (rho = 0.59), and poverty (rho = 0.58; all p < 0.001), and with SCD-related functional impairment were prevalence of poverty (rho = 0.71), diabetes (rho = 0.68), and hypertension (rho = 0.53; all p < 0.001). DISCUSSION: This study highlights critical links between SCD and socioeconomic and medical determinants in adults aged ≥ 45 in the United States, including the prevalence of poverty, diabetes, and hypertension. HIGHLIGHTS: State-level analysis reveals socioeconomic and medical risk factors for subjective cognitive decline (SCD) at a population level. The prevalence of poverty is a critical contributor to the state-level prevalence of SCD. The prevalence of diabetes and hypertension are also strong state-level determinants of SCD. Addressing the burden of cognitive decline at the population level necessitates targeting socioeconomic and medical factors.

Validity of the Tablet-Based Digital Cognitive Test (SCST) in Identifying Different Degrees of Cognitive Impairment.

BACKGROUND: As society ages, the incidence of Alzheimer's disease and other dementias has surged, highlighting the importance of early dementia diagnosis. The Seoul Cognitive Status Test (SCST), a digital neuropsychological test, is designed for the early detection of cognitive impairment and has been standardized to establish reliability and validity. This study aims to verify whether the SCST effectively discriminates between groups based on three cognitive statuses (subjective cognitive decline [SCD], mild cognitive impairment [MCI], Dementia) in a large sample. We also seek to determine whether the SCST discriminates between individuals with three different cognitive statuses as defined by the Cognitive Dementia Rating (CDR). METHODS: We enrolled 254 participants from a dementia clinic who underwent a comprehensive neuropsychological battery (Seoul Neuropsychological Screening Battery-II) during the dementia evaluation by experienced neurologists (55 with SCD, 126 with MCI, 73 with dementia). In addition, the degree of cognitive decline in participants was classified by CDR level (186 with CDR 0.5, 52 with CDR 1, 15 with CDR 2). One-way analysis of variance was used to compare SCST scores according to each of the three cognitive status groups and CDR levels. RESULTS: The SCST total score, cognitive domain scores (attention, language, visuospatial function, memory, executive function), and most of the subtest scores decreased significantly in the order of SCD, MCI and dementia. Likewise, the differences in SCST scores between CDR levels were significant, particularly in distinguishing between CDR 0.5 and CDR 1. CONCLUSION: This study reaffirmed that the SCST can significantly discriminate between groups of individuals with SCD, MCI, and dementia based on a large sample. Furthermore, differences in SCT scores were found across the levels of CDR, confirming the clinical utility of the SCST. These findings suggest that the SCST is an efficient and useful neuropsychological test for the sensitive detection of early cognitive impairment.

An effective screening model for subjective cognitive decline in community-dwelling older adults based on gait analysis and eye tracking.

Objective: To evaluate the effectiveness of multimodal features based on gait analysis and eye tracking for elderly people screening with subjective cognitive decline in the community. Methods: In the study, 412 cognitively normal older adults aged over 65 years were included. Among them, 230 individuals were diagnosed with non-subjective cognitive decline and 182 with subjective cognitive decline. All participants underwent assessments using three screening tools: the traditional SCD9 scale, gait analysis, and eye tracking. The gait analysis involved three tasks: the single task, the counting backwards dual task, and the naming animals dual task. Eye tracking included six paradigms: smooth pursuit, median fixation, lateral fixation, overlap saccade, gap saccade, and anti-saccade tasks. Using the XGBoost machine learning algorithm, several models were developed based on gait analysis and eye tracking to classify subjective cognitive decline. Results: A total of 161 gait and eye-tracking features were measured. 22 parameters, including 9 gait and 13 eye-tracking features, showed significant differences between the two groups (p < 0.05). The top three eye-tracking paradigms were anti-saccade, gap saccade, and median fixation, with AUCs of 0.911, 0.904, and 0.891, respectively. The gait analysis features had an AUC of 0.862, indicating better discriminatory efficacy compared to the SCD9 scale, which had an AUC of 0.762. The model based on single and dual task gait, anti-saccade, gap saccade, and median fixation achieved the best efficacy in SCD screening (AUC = 0.969). Conclusion: The gait analysis, eye-tracking multimodal assessment tool is an objective and accurate screening method that showed better detection of subjective cognitive decline. This finding provides another option for early identification of subjective cognitive decline in the community.

Structural disruption in subjective cognitive decline and mild cognitive impairment.

Subjective cognitive decline (SCD) marks the initial stage in Alzheimer's disease continuum. Nonetheless, current research findings regarding brain structural changes in the SCD are inconsistent. In this study, 37 SCD patients, 28 mild cognitive impairment (MCI) patients, and 42 healthy controls (HC) were recruited to investigate structural alterations. Morphological and microstructural differences among the three groups were analyzed based on T1- and diffusion-weighted images, correlating them with neuropsychological assessments. Additionally, classification analysis was performed by using support vector machines (SVM) categorize participants into three groups based on MRI features. Both SCD and MCI showed decreased volume in left inferior parietal lobe (IPL) compared to HC, while SCD showed altered morphologies in the right inferior temporal gyrus (ITG), right insula and right amygdala, and microstructures in fiber tracts of the right ITG, lateral occipital cortex (LOC) and insula relative to MCI. Moreover, the volume in the left IPL, right LOC, right amygdala and diffusivity value in fiber tracts of right LOC were significantly correlated with cognitive functions across all subjects. The classification models achieved an accuracy of > 0.7 (AUC = 0.8) in distinguishing the three groups. Our findings suggest that SCD and MCI share similar atrophy in the IPL but show more differences in morphological and microstructural features of cortical-subcortical areas.

Association between blood-based protein biomarkers and brain MRI in the Alzheimer's disease continuum: a systematic review.

Blood-based biomarkers (BBM) are becoming easily detectable tools to reveal pathological changes in Alzheimer's disease (AD). A comprehensive and up-to-date overview of the association between BBM and brain MRI parameters is not available. This systematic review aimed to summarize the literature on the associations between the main BBM and MRI markers across the clinical AD continuum. A systematic literature search was carried out on PubMed and Web of Science and a total of 33 articles were included. Hippocampal volume was positively correlated with Aß42 and Aß42/Aß40 and negatively with Aß40 plasma levels. P-tau181 and p-tau217 concentrations were negatively correlated with temporal grey matter volume and cortical thickness. NfL levels were negatively correlated with white matter microstructural integrity, whereas GFAP levels were positively correlated with myo-inositol values in the posterior cingulate cortex/precuneus. These findings highlight consistent associations between various BBM and brain MRI markers even in the pre-clinical and prodromal stages of AD. This suggests a possible advantage in combining multiple AD-related markers to improve accuracy of early diagnosis, prognosis, progression monitoring and treatment response.

The influence of education in predicting conversion from Subjective cognitive decline (SCD) to objective cognitive impairment: A systematic review and meta-analysis.

BACKGROUND: Subjective cognitive decline (SCD) is considered a pre-symptomatic stage of dementia characterized by cognitive complaints. The ability of education to reduce the risk of dementia is well known. Our objective is to investigate the influence of education on the risk of progression from SCD to MCI or dementia. METHODS: Prospective longitudinal studies of adults (≥50 years) with SCD evaluating progression to objective cognitive decline, MCI, or dementia were selected. Pooled estimates (random effects model) and 95 % confidence intervals were calculated, exploring heterogeneity. Standardized education differences, Odds Ratio, or Hazard Ratio between converters and non-converters were estimated. RESULTS: The systematic review carried out showed that high education, as well as other cognitive reserve proxies, delays cognitive decline. The first meta-analysis showed a significant association of SCD with conversion in both high and low education strata. A second meta-analysis considering education as a continuous variable found that SCD converters showed two years less education than non-converters. CONCLUSIONS: Our results suggest that education has a delaying effect against cognitive decline progression. The presumed improvement in accurately detecting cognitive decline associated with better metacognitive skills in higher-educated SCD participants does not seem to neutralize the incremental risk of objective cognitive decline associated with lower educational attainment.

Impact of multiple infections on risk of incident dementia according to subjective cognitive decline status: a nationwide population-based cohort study.

Background: The interrelation between infections, subjective cognitive decline (SCD), and dementia development is recognized, but not fully understood. This study explored the combined effect of specific infections and SCD on the risk of dementia. Objectives: To assess the influence of Helicobacter pylori, herpes simplex virus, varicella-zoster virus, and human papillomavirus on dementia risk in individuals with varying cognitive statuses, especially focusing on those with and without SCD. Methods: A cohort of 1,100,540 participants aged 66 years from the Korean National Health Insurance Service was divided into cognitively preserved (CP, n = 825,405) and SCD (n = 275,135) groups. This study analyzed the effects of single, dual, and triple infections on the risk of overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD) using incidence rates and hazard ratios. Results: The SCD group consistently showed a doubled risk of dementia, particularly AD, regardless of the number of infections. In the initial data, both the presence and number of infections, especially in the CP group, were associated with an increased dementia incidence and risk; however, this correlation disappeared after adjusting for covariates, hinting at a possible protective effect. Conclusion: Our findings emphasize that, while SCD is a steadfast risk factor for dementia, the role of infections is layered, subject to various influences, and requires more comprehensive exploration to fully understand their impact on dementia development.

Gender differences in neurocognitive assessments: insights from a pilot study with the International Neurocognitive Test Profile (INCP) digital battery.

BACKGROUND: The aging global population has led to an increase in the number of dementia diagnoses, with projections indicating a continued upward trend. This demographic change presents profound challenges for patients, their families, and healthcare systems worldwide. Consequently, the demand for reliable and user-friendly screening tools that can detect dementia at early stages and monitor its progression is more critical than ever. The International Neurocognitive Test Profile (INCP), developed at the Medical University of Vienna, aims to address this need by offering a digital test battery for the early detection of dementia. This study forms a part of the INCP's ongoing development and evaluation, specifically investigating the influence of gender on test outcomes. METHODS: Seventy participants, recruited through flyers at the Vienna General Hospital, completed the INCP assessment using tablets as part of the study. The effect of gender on performance across various INCP subtests was analyzed using Mann-Whitney U tests. For further exploratory analysis, a correlation matrix was calculated encompassing demographic variables (age and education), screening data, and all INCP subtests. RESULTS: The analysis revealed significant gender differences in two INCP subtests related to executive functions. Males outperformed females on the Figure Fluency Test (r = 0.30, indicating a moderate effect) and the Dice 2­n Back Test (r = 0.29, indicating a small effect). However, when correcting for multiple comparisons, no significant gender disparities were observed in the scores of the subtests. CONCLUSION: The identification of possible gender differences in specific subtests underscores the importance of considering gender as a variable in the further development and evaluation of the INCP. These findings offer valuable insights for the design and planning of future studies involving the INCP.

Subjective cognitive decline and cognitive change among diverse middle-aged and older Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA).

INTRODUCTION: The potential utility of subjective cognitive decline (SCD) as an early risk marker of Alzheimer's disease and related dementias is under consideration. We examined associations between SCD and cognitive change among middle-aged and older Hispanic/Latino adults living in the United States. METHODS: The short-form Everyday Cognition Scale (ECog-12) was assessed to generate global, executive function, and memory-related SCD scores. We used survey generalized regressions to model the change in learning, memory, verbal fluency, executive function, and global cognitive performance over 7 years as a function of SCD (at Visit 2). RESULTS: The mean age was 56.37 ± 8.10 years at Visit 1 (n = 6225). Higher ECog-12 was associated with greater decline in global cognitive performance (ECog-12 global: B = -0.17, standard error [SE] = 0.02; ECog-12 executive: B = -0.15, SE = 0.02; ECog-12 memory: B = -0.14, SE = 0.02, p's < 0.001). DISCUSSION: These results support the link between subjective reports of cognitive decline and objectively measured 7-year cognitive decline in community-dwelling, middle-aged, and older Hispanic/Latino adults. HIGHLIGHTS: We found that nearly two-thirds of diverse middle-aged and older Hispanics/Latinos reported cognitive concerns in a large and representative population study. Self-reported subjective experiences of cognitive decline reflect objective cognitive decline in US Hispanics/Latinos. The relationship is stronger among men compared to women. The relationship between subjective and objective changes to memory are stronger in those with cognitive concerns, and remain even in cognitively healthy individuals.

Just as expected? Older adults' aging expectations are associated with subjective cognition.

OBJECTIVES: This study investigated the relationship between older adults' expectations regarding aging and subjective cognition. Specifically, we examined whether the three domains of aging expectations (physical health, mental health, and cognitive function) were associated with two aspects of subjective cognition: current subjective cognition and subjective cognitive decline (SCD). METHOD: An online survey was conducted among U.S. adults aged 65-90 (N = 581; Mage=71.4, SD ± 4.81; 51% female). Measures included the 12-item Expectations Regarding Aging scale, the 8-item PROMIS Cognitive Abilities scale (current subjective cognition), and the 12-item Everyday Cognition scale (SCD). We used generalized linear models to examine associations between overall aging expectations and its three domains with current subjective cognition ratings and SCD. RESULTS: We found that more positive expectations regarding physical health, mental health, and cognitive function in aging were associated with higher ratings of current subjective cognition as well as lower SCD. The magnitude of effects across aging expectations domains were similar for both aspects of subjective cognition. CONCLUSION: Aging expectations are malleable and influence an individual's perceptions of their cognitive functioning. Modifying older adults' aging expectations could support healthier cognitive aging through increased awareness and accurate assumptions about the aging process.

Self- and study partner-reported cognitive decline in older adults without dementia: The role of α-synuclein and amyloid biomarkers in the Alzheimer's Disease Neuroimaging Initiative.

INTRODUCTION: Subjective cognitive decline (SCD) may be an early marker of Alzheimer's disease (AD) pathology. Until recently, it was impossible to measure biomarkers specific for α-synuclein pathology; therefore, its association with subjective reports of cognitive decline is unknown. METHODS: Alzheimer's Disease Neuroimaging Initiative participants without dementia (n = 918) were classified as positive or negative for amyloid beta (Aß+ or Aß-) and α-synuclein (α-syn+ or α-syn-) biomarkers. Self- and study partner-reported cognitive decline was measured with the Everyday Cognition (ECog) questionnaire. RESULTS: Per self-report, Aß+/α-syn+ had the greatest cognitive decline. Aß-/α-syn+ did not differ from Aß-/α-syn- across ECog scores. Study partner-reported results had a similar pattern, but Aß+/α-syn- and Aß+/α-syn+ did not differ across ECog scores. Mild cognitive impairment classification moderated the study partner-reported memory score. DISCUSSION: While α-syn+ alone did not increase subjective reports of cognitive decline, Aß+/α-syn+ had the most self- and study partner-rated cognitive decline. Therefore, the presence of multiple pathologies was associated with greater SCD. HIGHLIGHTS: Cerebrospinal fluid α-synuclein (α-syn) seed amplification assay was used to determine α-syn positivity. Amyloid beta (Aß)-/α-syn-, Aß-/α-syn+, Aß+/α-syn-, and Aß+/α-syn+ biomarker groups were created. Aß+/α-syn+ had greater subjective cognitive decline (SCD) than the other biomarker groups. Aß-/α-syn+ did not differ from Aß-/α-syn- across self- or study-partner reported SCD scores. Study partner-reported subjective memory results were largely driven by participants with mild cognitive impairment.

Resting-state functional connectivity abnormalities in subjective cognitive decline: A 7T MRI study.

Resting-state functional connectivity (FC) MRI is sensitive to brain changes in Alzheimer's disease in preclinical stages, however studies in persons with subjective cognitive decline (SCD) have reported conflicting findings, and no study is available at 7T MRI. In this study, we investigated FC alterations in sixty-six participants recruited at the Geneva Memory Center (24 controls, 14 SCD, 28 cognitively impaired [CI]). Participants were classified as SCD if they reported cognitive complaints without objective cognitive deficits, and underwent 7T fMRI to assess FC in canonical brain networks and their association with cognitive/clinical features. SCD showed normal cognition, a trend for higher depressive symptoms, and normal AD biomarkers. Compared to the other two groups, SCD showed higher FC in frontal default mode network (DMN) and insular and superior temporal nodes of ventral attention network (VAN). Higher FC in the DMN and VAN was associated with worse cognition but not depression, suggesting that hyper-connectivity in these networks may be a signature of age-related cognitive decline in SCD at low risk of developing AD.

Capturing subjective cognitive decline with a new combined index in low education patients with Parkinson's disease.

Objectives: Subjective Cognitive Decline (SCD) refers to self-reported cognitive decline with normal global cognition. This study aimed to capture SCD among low educated patients with Parkinson's disease (PD) using a newly established indicator. Methods: We recruited 64 PD patients with low education levels (education ≤12 years) for the study. The presence of SCD was determined based on a Unified Parkinson's Disease Rating Scale Part I (1.1) score ≥ 1. Spearman analysis and multivariate binary logistic regression analyses were conducted to investigate factors associated with the PD-SCD group. The receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of the new combined index. Results: The prevalence of SCD in PD patients was 43.75%. Low educated PD-SCD patients had higher scores on the Non-Motor Symptoms Scale (NMSS), Parkinson's Fatigue Scale (PFS), Epworth Sleepiness Scale (ESS), as well as higher scores on the UPDRS-I and UPDRS-II, compared to PD patients without SCD. They also demonstrated poorer performance on the Montreal Cognitive Assessment (MoCA), particularly in the domains of executive abilities/attention/language. Multivariate binary regression confirmed the significant association between PD-SCD and MoCA-executive abilities/attention/language. Based on these findings, a combined index was established by summing the scores of MoCA-executive abilities, MoCA-attention, and MoCA-language. ROC analysis showed that the combined index could differentiate PD-SCD patients with an area under the curve (AUC) of 0.876. A score of 12 or less on the combined index had a sensitivity of 73.9% and a specificity of 76.2% for diagnosing PD-SCD. Conclusion: These low education patients with PD-SCD may exhibit potential PD-related pathological changes. It is important for clinicians to identify PD-SCD patients as early as possible. The newly combined index can help capture these low educated PD-SCD patients, with an AUC of 0.867, and is expected to assist clinicians in earlier identification and better management of PD patients.

Subjective cognitive and olfactory impairments predict different prospective dementia outcomes.

Self-reported measures emerge as potential indicators for early detection of dementia and mortality. We investigated the predictive value of different self-reported measures, including subjective cognitive decline (SCD), subjective olfactory impairment (SOI), subjective taste impairment (STI), and self-reported poor health (SPH), in order to determine the risk of progressing to Alzheimer's disease (AD) dementia, Parkinson's disease (PD) dementia, or any-other-cause dementia. A total of 6,028 cognitively unimpaired individuals from the 8th wave of the English Longitudinal Study of Ageing (ELSA) were included as the baseline sample and 5,297 individuals from the 9th wave were included as 2-year follow-up sample. Self-rated measures were assessed using questions from the ELSA structured interview. Three logistic regression models were fitted to predict different the dementia outcomes. SCD based on memory complaints (OR = 11.145; P < 0.001), and older age (OR = 1.108, P < 0.001) significantly predicted the progression to AD dementia at follow-up. SOI (OR = 7.440; P < 0.001) and older age (OR = 1.065, P = 0.035) significantly predicted the progression to PD dementia at follow-up. Furthermore, SCD based on memory complaints (OR = 4.448; P < 0.001) jointly with complaints in other (non-memory) mental abilities (OR = 6.662; P < 0.001), and older age (OR = 1.147, P < 0.001) significantly predicted the progression to dementia of any other cause. Different types of complaints are specifically associated with different dementia outcomes. Our study demonstrates that self-reported measures are a useful and accessible tool when screening for individuals at risk of dementia in the general population.

Behavioral Alterations of Spatial Cognition and Role of the Apolipoprotein E-ε4 in Patients with MCI Due to Alzheimer's Disease: Results from the BDSC-MCI Project.

Background: Beyond memory deterioration, spatial disorientation may occur along the continuum of normal aging-dementia of Alzheimer's type. The present study aims at detecting behavioral disorders of spatial cognition in prodromal Alzheimer's disease (AD) and verifying the association between Apolipoprotein E-ε4 (ApoE-ε4) genotype and gait patterns during a real-world naturalistic task. Methods: A sample of 58 elderly participants, of which 20 patients with mild cognitive impairment with CFS biomarker evidence of AD, 23 individuals with subjective cognitive decline (SCD), and 15 healthy controls (HCs), was tested by a modified version of the Detour Navigation Test (DNT-mv). Generalized linear models were run to explore the association between group belonging and wrong turns (WTs)/moments of hesitation (MsH) as behavioral disorientation scores of the DNT-mv as well as the effect of ApoE-ε4 genotype on time and walking speed registered by a smartphone app providing GPS tracking of body movement around urban environments. Results: Patients with MCI due to AD reported more WTs than individuals with SCD and HCs. Further, the ApoE-ε4 genotype determined a lower capacity in spatial information processing, influencing gait during naturalistic spatial navigation tasks. Conclusions: Behavior alterations of spatial cognition can be detected ecologically in prodromal AD. The use of technological solutions supporting gait analysis may help in corroborating the experimental observation.

Association between Multi-Domain Lifestyle and Objective Cognitive Impairment in Elderly People with SCD and MCI in Chinese Communities.

OBJECTIVES: Controlling the lifestyle associated with dementia risk can delay the process of cognitive decline. Subjective cognitive decline (SCD) and mild cognitive impairment (MCI) are early states in the development of dementia and are also the window period for early intervention in dementia. The purpose of this study was to explore the association between multi-domain lifestyle and objective cognitive impairment in elderly people with SCD and MCI in Chinese communities and to provide reference for effective implementation of precise health management measures to reduce the risk of dementia. METHODS: A total of 265 middle-aged and elderly volunteers recruited from the community were divided into SCD group (107 cases), MCI group (80 cases), and healthy control (HC) group (78 cases). All participants received clinical interview, examination, and cognitive assessments. RESULTS: The total Dementia Risk Reduction Lifestyle Scale (DRRLS) scores in the HC, SCD, and MCI groups [110.00 (11.25) vs. 101.00 (10.00) vs. 79.50 (20.75)] exhibited statistically significant differences among them. The total score of the DRRLS showed a significant negative correlation with the Trail-Making Test (TMT), and significant positive correlations with both the Verbal Fluency Test (VFT) and Auditory Verbal Learning Test (AVLT) scores (p < 0.05). After adjusting for confounding factors, such as age and years of education, multiple linear regression analysis revealed several points. In the SCD group, brain-strengthening exercise and interpersonal relationship scores were negatively correlated with TMT scores (ß = -11.257, -15.077; all p < 0.05), while health responsibility, smoking control behavior, and interpersonal relationship scores were positively correlated with AVLT scores (ß = 0.485, 0.344, and 0.406; all p < 0.05). In the MCI Group, brain-strengthening exercise, brain-healthy diet, and interpersonal relationship were negatively correlated with TMT (ß = -22.011, -16.206, -11.696; all p < 0.01), whereas health responsibility, mental activity, smoking control behavior, interpersonal relationship, and stress management were positively correlated with AVLT (ß = 0.450, 0.435, 0.308, 0.256, 0.607; all p < 0.05). CONCLUSIONS: In Chinese communities, the unhealthy lifestyle of elderly individuals with SCD and MCI is significantly associated with cognitive function impairment. The greater their unhealthy lifestyle habits, the more pronounced the scope and severity of cognitive function impairment becomes. Furthermore, different dimensions of lifestyle have varying impacts on cognitive domains.

Neuropsychological Correlates of Clinical Progression in Subjective Cognitive Decline.

Background: Subjective cognitive decline (SCD) refers to self-reported cognitive decline in individuals with normal performance on standardized cognitive tests. Understanding the factors predicting progression from SCD to mild cognitive impairment (MCI) is crucial, as approximately 14% of SCD cases progress to dementia and about 27% develop MCI over four years. Objective: This study aims to identify neuropsychological predictors of progression from SCD to MCI, focusing on cognitive domains assessed through neuropsychological tests. Methods: This retrospective study at Seoul National University Bundang Hospital analyzed a cohort of 107 patients diagnosed with SCD through comprehensive assessment. Patients underwent annual neuropsychological testing, including the Digit Span Test, Boston Naming Test, Rey Complex Figure Test, Seoul Verbal Learning Test, and Stroop Test. Results: Annually, these patients underwent neuropsychological tests over a 5-year period; 24 progressed to MCI per NIA-AA criteria. Key predictors of MCI progression included age, ischemic heart disease, and scores from the forward digit span, delayed recall, and Boston naming tests. Lower scores in delayed recall and Boston naming tests significantly correlated with a higher risk of MCI (p < 0.001). Conclusions: These findings suggest a need for targeted management of memory and language functions to monitor disease progression effectively.

Subjective cognitive decline is associated with altered patterns of brain activity and connectivity during performance of an old/new recognition memory task.

INTRODUCTION: Subjective Cognitive Decline (SCD) is considered a preclinical stage within the AD continuum. Knowledge about the functional changes in the brain associated with episodic memory retrieval and novelty recognition in people with SCD is currently very limited. METHOD: The study aimed to evaluate behavioural and neurofunctional changes in individuals with SCD, measured relative to a control group, during successful episodic memory retrieval and novelty recognition, as well as to compare the functional connectivity patterns related to these cognitive processes within the Default Mode Network (DMN) in both groups. Participants performed an old/new recognition memory task with words while the BOLD signal was acquired. RESULTS: No between-group differences were observed in the performance of the episodic memory task. However, during the successful recognition of old words, the SCD group showed brain hypoactivity in the right rolandic operculum and reduced functional connectivity between the DMN and the fronto-parietal control network (FPCN). During the correct identification of new words, the SCD group also showed reduced connectivity between the DMN and the FPCN, and lower connectivity within the DMN. CONCLUSION: Despite the absence of objective evidence of cognitive impairment, people with SCD display several changes in brain activity and connectivity associated with episodic memory retrieval and novelty recognition.

Diagnosis of Alzheimer's Disease in Clinical Practice: Time to Incorporate Biomarkers?

Hippocampal dysfunction is associated with early clinical signs of Alzheimer's disease (AD). Due to the limited availability or invasiveness of current biomarkers, the AD diagnosis is usually based on cognitive assessment and structural brain imaging. The recent study by Lalive and colleagues examined the specificity of brain morphometry for the AD diagnosis in a memory clinic cohort with hippocampal-type amnestic syndrome. The results indicate that memory deficits and hippocampal atrophy are similar in AD and non-AD patients, highlighting their low diagnostic specificity. These findings challenge the traditional AD diagnosis and underscore the need for biomarkers to differentiate specific neuropathological entities.

Effects of Rehabilitation Training on Cognitive Function in Parkinson's Disease with Subjective Cognitive Decline.

Purpose: To characterize Subjective Cognitive Decline (SCD) in Parkinson's disease (PD) and its progression, as well as to assess the impact of rehabilitation training programs on cognitive function in PD patients. Patients and Methods: The study involved 42 patients diagnosed with PD. Participants underwent evaluation using a neuropsychological protocol and were subsequently classified into two groups: those with SCD (PD-SCD+, n= 22) or those without (PD-SCD-, n= 20). After an average follow-up period of 3.0 years (2.7-4.6 years), cognitive assessments were reiterated with the same group of subjects. Following the re-assessment, all 42 patients participated in a six-month rehabilitation training program, concluding with the reevaluation of cognitive performance. Results: In the follow-up assessment, it was observed that PD-SCD+ experienced a more pronounced annual decline in cognitive function, as measured by the Chinese-Beijing version of Montreal Cognitive Assessment (BJ-MoCA) test and semantic fluency, compared to PD-SCD-. A stepwise logistic regression analysis identified low MMSE scores (P< 0.001), elevated HAMD scores (P= 0.008), male gender (P= 0.026), and the presence of SCD (P= 0.022) associated with diminished language skills in PD patients. Both groups of PD patients exhibited improvements in BJ-MoCA scores after participating a six-month rehabilitation training program. Particularly notable is the statistically significant improvement in language skills observed in patients with PD-SCD+ compared to PD-SCD- patients following rehabilitation training. Conclusion: As PD progresses, individuals with PD-SCD+ tend to experience more pronounced cognitive decline compared to those with PD-SCD-. Semantic fluency emerges as a crucial component for assessing the cognitive subset of PD, potentially serving as an indicator of cognitive decline in individuals with PD. Evidence suggests that rehabilitation training is a viable intervention for individuals diagnosed with PD. This intervention not only improves various cognitive domains but also leads to more substantial enhancements in language skills.