Course Of Mild Cognitive Impairment Research Articles

Comparison of the possibility of categorising proper names and common names in a disturbed discourse (in the course of mild cognitive impairment accompanying Parkinson’s disease)

The aim of the study is an assessment of the possibility of semantic categorisation of common names and proper names in a disturbed discourse. The study used a case-experimental approach. The results were analysed qualitatively and quantitatively. The best-preserved semantic relations were indicated and phenomena relating to the quality of access to the mental dictionary were determined. The symptoms of the degradation of the semantic dictionary were indicated. The quantitative assessment included a percentage description of the results obtained. The subject performed the process of semantic categorisation of proper names (names belonging to less fuzzy categories) better than common names (with numerous connotations). Keywords: proper names – common names – categorisation – MCI – semantic dictionary – disturbed discourse.

Burden of Illness in People with Alzheimer’s Disease: A Systematic Review of Epidemiology, Comorbidities and Mortality

BackgroundAlzheimer’s disease (AD) is the most common neurodegenerative disease worldwide, and an updated quantification of its impact on morbidity, disability, and mortality is warranted. We conducted a systematic literature review, focusing on the past decade, to characterize AD and assess its impact on affected individuals.MethodsSearches of Embase, MEDLINE, and the Cochrane Library were conducted on August 7, 2020 and updated on November 10, 2021. Observational studies from any country reporting incidence, prevalence, comorbidities, and/or outcomes related to disability and mortality/life expectancy, in people with mild cognitive impairment (MCI) due to AD, or mild, moderate, or severe AD dementia, were considered relevant.ResultsData were extracted from 88 studies (46 incidence/prevalence; 44 comorbidities; 25 mortality-/disability-related outcomes), mostly from Europe, the USA, and Asia. AD dementia diagnosis was confirmed using biomarkers in only 6 studies. Estimated 5-year mortality in AD was 35%, and comorbidity prevalence estimates varied widely (hypertension: 30.2–73.9%; diabetes: 6.0–24.3%; stroke: 2.7–13.7%). Overall, people with AD dementia were more likely to have cardiovascular disease or diabetes than controls, and 5-year mortality in people with AD dementia was double that in the age- and year-matched general population (115.0 vs 60.6 per 1,000 person-years).ConclusionsAD is associated with excess morbidity and mortality. Future longitudinal studies of population aging, incorporating biomarker assessment to confirm AD diagnoses, are needed to better characterize the course of MCI due to AD and AD dementia.

Saccadic Eye Movements in Patients with Mild Cognitive Impairment: A Longitudinal Study

Saccadic eye movements are one of the sensitive and noninvasive methods to help monitor the cognitive course of mild cognitive impairment (MCI). The study aimed to evaluate both pro and anti-saccade longitudinally and the relationship between cognitive functions and eye movements in MCI subgroups and healthy controls (HCs) at a two-year follow-up. This study revealed that the anti-saccade anticipatory responses decreased in amnestic MCI (aMCI). Correct vertical pro-saccades increased in non-amnestic MCI (naMCI), while the express saccades decreased. Our study demonstrated that longer than two years of follow-up is necessary to monitor the course of MCI. Findings of the relationships between longitudinal changes of saccades and cognitive measurements demonstrated the usability of eye movements in evaluating the process of MCI.

A Long Short-Term Memory Based Framework for Early Detection of Mild Cognitive Impairment From EEG Signals

Mild cognitive impairment (MCI) is an irreparable progressive neuro-degenerative disorder, which seems to be a precursor to Alzheimer’s disease (AD) that may lead to dementia in elderly people. It is a major public health challenge for healthcare in the 21st century. Because there is no curative or therapy to halt or reverse the course of MCI, early identification is critical for successful treatment programs to enhance patients’ quality of life. Currently, Electroencephalography (EEG) has been emerged as an efficient tool to investigate MCI. Traditional methods for finding MCI from EEG data use shallow machine learning-based architectures that cannot find important biomarkers in deep, hidden layers of the data and also have trouble dealing with a large amount of EEG data. To reduce this issue, this research will use EEG data to provide a deep learning-based framework using the Long Short-term Memory (LSTM) model for effective identification of MCI individuals from healthy volunteers (HV). The suggested framework consists of four phases: denoising, segmentation, downsampling, uncovering deep hidden features using the LSTM model, and identifying MCI patients with the sigmoid classifier. This study has designed 20 different LSTM models and investigated them to a publicly available MCI database to find out the best one. After performing 5-fold cross validation, the best model achieved 96.41% of accuracy, 96.55% of sensitivity and 95.95% of specificity. The proposed LSTM-based deep learning model provides a robust biomarker and guide technologists to create a new automatic diagnosis system for MCI detection.

A deep learning based framework for diagnosis of mild cognitive impairment

Detecting mild cognitive impairment (MCI) from electroencephalography (EEG) data is a challenging problem as existing methods rely on machine learning based shallow architectures that are unable to successfully uncover relevant biomarkers from deep hidden layers of data. This study will design a deep learning-based framework including a Gated Recurrent Unit (GRU) model for effective detection of MCI participants from healthy control (HC) subjects utilizing EEG data. MCI is a gradual, irreversible neurodegenerative illness that is frequently a precursor to Alzheimer’s disease (AD) and can result in dementia in elderly. There is no cure or treatment to stop or reverse the course of MCI, early identification is critical for successful application of treatment strategies to enhance the quality of life of patients. The proposed framework consists of four steps: gathering raw EEG data, preprocessing of raw data (de-noising, segmentation, and down sampling), uncovering hidden features and classification of MCI subjects from normal subjects, and performance evaluation of the proposed model. The proposed GRU model has been compared with long short-term memory (LSTM), support vector machine (SVM), and K-nearest neighbor (KNN) classifiers. The stability of the framework is evaluated through 5-fold cross validation. The suggested GRU-based deep learning model serves as a reliable biomarker and aids technicians in developing a new automatic MCI detection method.

Reduced parietal activation in participants with mild cognitive impairments during visual-spatial processing measured with functional near-infrared spectroscopy

Functional Near Infrared Spectroscopy (fNIRS) may be a suitable, simple, and cost-effective brain imaging technique for detecting divergent neuronal patterns at an early stage of neurodegeneration. In course of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD), a deficit in visual-spatial processing, located in the parietal cortex, is a reliable risk factor. Earlier, we established the application of the clock-hand-angle-discrimination task (ADT) during fNIRS to identify neuronal correlates of the visual-spatial processing in a healthy elderly sample. In this analysis, we aimed to measure and find out differences in the hemodynamic response in MCI participants compared to matched healthy controls. As expected, MCI participants showed more errors over all conditions of pointer length and a higher reaction time in the long and middle pointer length condition. Moreover, results revealed a significant reduction of cortical activation in MCI patients. There was a generally increased activity in both the right as compared to the left hemisphere and the superior parietal brain region as compared to the inferior parietal brain region in both groups. In summary, fNIRS can be implemented in the measurement of visual-spatial processing in MCI patients and healthy elderly based on ADT. MCI participants had difficulties to cope with the ADT. Since neuronal hypoactivity occurs with concomitant behavioral deficits, an additional analysis was performed on a subgroup of MCI patients who performed as well as the control group in behavior. This subgroup analysis also showed a hypoactivation of the parietal cortex, without evidence of a compensatory activation. Therefore, we assume that MCI patients are characterized by a deficit in the parietal cortex. Overall, these findings confirm our hypothesis that hemodynamic deficits in visual-spatial processing, localized in the parietal cortex, are reliable and early diagnostic markers for cognitive decline in risk groups for the development of AD.

Predictors of Incident Mild Cognitive Impairment and Its Course in a Diverse Community-Based Population.

Background and ObjectivesTo investigate sociodemographic and medical predictors of incident mild cognitive impairment (MCI) and subsequent course of MCI at follow-up, including sustained MCI diagnosis, classification as cognitively normal, and progression to dementia.MethodsWithin a community-based cohort, diagnoses of MCI were made with a published algorithm. Diagnosis of dementia was based on clinical consensus. Cox regressions estimated hazard ratios of incident MCI associated with several predictors. Modified Poisson regressions estimated relative risks associated with predictors of diagnostic status at follow-up after incidence.ResultsAmong 2,903 cognitively normal participants at baseline, 752 developed MCI over an average of 6.3 (SD 4.5) years (incidence rate 56 per 1,000 person-years). Presence of APOE ε4 and higher medical burden increased risk of incident MCI, while more years of education, more leisure activities, and higher income decreased this risk. Of the incident MCI cases, after an average of 2.4 years of follow-up, 12.9% progressed to dementia, 9.6% declined in functioning and did not meet the algorithmic criteria for MCI but did not meet the clinical criteria for dementia, 29.6% continued to meet MCI criteria, and 47.9% no longer met MCI criteria. Multidomain MCI, presence of APOE ε4, depressive symptoms, and antidepressant use increased the risk of progression to dementia.DiscussionThis community-based study showed that almost half of the individuals with incident MCI diagnoses were classified as cognitively normal at follow-up. Predictors of incident MCI demonstrably differed from those of subsequent MCI course; these findings can refine expectations for cognitive and functional course of those presenting with MCI.

A prospective cohort study investigating contributors to mild cognitive impairment in adults with spinal cord injury: study protocol

BackgroundStudies report rates of mild cognitive impairment (MCI) in spinal cord injury (SCI) range between 10 and 60%. This broad estimate of MCI in SCI is most likely a result of: (i) inconsistent operationalization of MCI; (ii) heterogeneity among individuals with SCI; (iii) failure to account for MCI subtypes, thereby adding to the heterogeneity of samples; and, (iv) poor control for traumatic brain injury (TBI) that obscures differentiation of MCI attributable to TBI versus other factors. There is a paucity of longitudinal studies following the course of MCI in SCI, and none that account for multiple predictors of MCI, including interactions among predictors.MethodsAn inception cohort longitudinal study will assess approximately 100 individuals aged 17–80 years with acute SCI, with measures taken at three timepoints (baseline, 3 months post-baseline, and 12 months post-injury). Data relevant to medical care received within the first 24–48 h of presentation to the emergency department will be analysed, as will measures of cognition, injury characteristics, medical history, personal factors, psychological status, psychosocial functioning, and quality of life. Latent class mixture modelling will determine trajectories for the primary outcome of interest, cognitive functioning and its subtypes, and secondary outcomes of interest such as depression. Multiple regression analyses will identify predictors of MCI and its subtypes.DiscussionThe prospective design will reveal change in cognitive functioning across time and unveil different outcome trajectories; thus addressing the lack of knowledge on trajectories of MCI and MCI subtypes in SCI. Through subtyping MCI, we hope to yield groups of cognitively impaired individuals with SCI that are potentially more homogenous and thereby stable and predictable. This is the first study to capture emergency department and acute care diagnostic evidence of mild TBI, which has been poorly controlled in previous studies. Our study will also be the first to distinguish the contribution of TBI from other factors to the development of MCI in individuals with SCI.Trial registrationThe study was prospectively registered with the Australian and New Zealand Clinical Trial Registry (ACTRN12619001702101) on 3rd December 2019.

Diagnostic Stability of Mild Cognitive Impairment, and Predictors of Reversion to Normal Cognitive Functioning

Objective: Studies that investigate predictive factors for spontaneous recovery (reversion) from mild cognitive impairment (MCI) are only beginning to emerge, and the long-term course of MCI is not properly understood. We aimed to investigate stability of the MCI diagnosis, predictors for reversion, as well as the trajectory of MCI over the course of 12 years. Materials and Methods: Data were drawn from the Swedish population study: Good Aging in Skåne with MCI defined according to the expanded Mayo Clinic criteria. A total of 331 participants, aged 60–95 years with MCI, were used to investigate 6-year MCI stability and reversion, and 410 participants were used to inspect 12-year MCI trajectory. Predictors for reversion included demographical factors, psychological status, and factors tied to the cognitive testing session and the operationalization of the MCI criteria. Results: Over half (58%, 95% CI 52.7–63.3) of the participants reverted back to normal cognitive functioning at 6-year follow-up. Of those with stable MCI, 56.5% (95% CI 48.2–64.8) changed subtype. A total of 23.9% (95% CI 13.7–34.1) of the 6-year follow-up reverters re-transitioned back to MCI at 12-year follow-up. ORs for reversion were significantly higher in participants with lower age (60-year-olds: OR 2.19, 95% CI 1.08–4.43, 70-year-olds: OR 3.11, 95% CI 1.27–7.62), better global cognitive functioning (OR 1.15, 95% CI 1.03–1.29), good concentration (OR 2.53, 95% CI 1.06–6.05), and single-domain subtype (OR 2.68, 95% CI 1.51–4.75). Conclusion: Our findings provide further support that MCI reversion to normal cognitive functioning as well as re-transitioning to MCI is fairly common, suggesting that the MCI trajectory does not necessarily lead straight to dementia. Additionally, assessment of factors associated with reversion can aid clinicians to make accurate MCI progression prognosis.

Preliminary evidence for an increased likelihood of a stable trajectory in mild cognitive impairment in individuals with higher motivational abilities

BackgroundMotivational abilities (MA), that describe skills in relation to goal-oriented behavior, have recently been found to be associated with neuropathological aging. Here we examine the impact of MA on the long-term course of mild cognitive impairment (MCI).MethodsWe followed-up N = 64 individuals diagnosed with MCI (Mage = 73 years, 44% female) for 3 years. MA were assessed by long-term informants of the participants using two scales: motivation and decision regulation [Volitional Components Questionnaires, VCQ, (Kuhl and Fuhrmann, Decomposing self-regulation and self-control: the volitional components inventory, 1998)]. Cognitive abilities were assessed with the Mini Mental State Examination (J Psychiatr Res 12:189-98, 1975). Survival analyses and multilevel modeling (MLM) were applied to determine the predicting effect of informant-rated MA at baseline on the likelihood of MCI stability and on the trajectory of cognitive abilities.ResultsFifty percent (n = 32) of the MCI participants remained stable, while 32.8% (n = 21) and 17.2% (n = 11) converted to Alzheimer’s disease (AD) or dropped-out, respectively. Survival analyses revealed that MCI cases with higher-rated MA at baseline were more likely to exert a stable course in MCI over 3 years (p = 0.036) when controlling for demographic characteristics and executive function. MLM analyses indicated that higher informant-rated MA at baseline were significantly related to higher cognitive abilities, even when controlling for MCI subtype (p = 0.030).ConclusionsThis study provides preliminary longitudinal evidence for a lower risk of conversion to AD and higher cognitive abilities by higher rated MA at an early stage of MCI.

Inflection Point in Course of Mild Cognitive Impairment: Increased Functional Connectivity of Default Mode Network.

The alteration of the default mode network (DMN) functional connectivity (FC) has been reported in patients with amnestic mild cognitive impairment (aMCI) as a predictor of Alzheimer's disease (AD). However, no studies exist that examined stage-dependent DMN FC changes throughout the course of aMCI. The present study aims to characterize patterns of DMN FC over three aMCI stages as first defined. Utilizing the extreme groups approach on the performance of memory tasks, aMCI subjects were divided into mild, moderate, and severe stages. Independent component analysis was used to assess DMN for individual patients in each of the three cross-sectionally defined stages. Instead of finding that continued monotonic decline was the case for the hippocampus volume, which we also investigated in this study, we observed an increase in DMN functional connectivity from mild aMCI to moderate aMCI and a decrease to severe aMCI, mainly in the left precuneus and superior parietal lobe. Moreover, the FC was significantly associated with cognitive performance. Though a longitudinal study is needed to confirm these results, our cross-sectional finding is that non-linear FC changes in DMN could be a characteristic of prodromal early disease development.

ANTICHOLINERGICS INFLUENCE TRANSITION FROM NORMAL COGNITION TO MCI IN PRIMARY CARE OLDER ADULTS

The relationship between anticholinergics and early forms of cognitive impairment is not well defined. Our objective was to determine whether anticholinergic exposure influenced transitions in cognitive diagnosis among older adults with normal cognition or mild cognitive impairment (MCI) at baseline. We used data from an epidemiological study of the prevalence and course of MCI over time. Participants were 65 years or older recruited from a diverse primary care population in an urban health system in the US. Participants completed neuropsychologic assessment, informant interview, and full neurological and clinical exam with diagnosis defined by an expert panel at baseline and every 12 months. Transitions included normal cognition to MCI or dementia, and MCI to normal cognition or dementia. Anticholinergic use was defined by dose and duration fields of pharmacy dispensing and claims records to calculate cumulative exposure during each 12-month period. Logistic regression models with generalized estimating equations were used to compare transitions with stable diagnoses. The study was approved by the Institutional Review Board of IUPUI in Indianapolis. Among 350 participants, the mean age at baseline was 71 years, 79% were female and 62% were African American. Seventy-two percent used at least one mild anticholinergic medication. A total of 978 diagnostic assessments were completed: 221 (60.7%) with MCI were stable; 135 (37.1%) with MCI transitioned to normal; 8 (2.2%) with MCI transitioned to dementia; 511 (83.2%) with normal cognition were stable; and 103 (16.8%) with normal cognition transitioned to MCI. Compared to stable cognition, strong anticholinergic use increased the likelihood of transition from normal cognition to MCI after adjusting for age, gender, race, education, comorbidities, and APOE (odds ratio 1.34; 95% confidence interval: 1.04–1.74; p-value 0.0253). Compared to stable MCI, the odds ratio for the transition of MCI to normal showed a preventative trend among strong anticholinergic users, however this relationship was not statistically significant after similar adjustments (OR 0.92; 95% CI: 0.73–1.15; p-value 0.4675). Use of strong anticholinergic medications adversely influences cognitive diagnosis even in early stages of cognitive impairment. Interventions reducing anticholinergics should be tested to prevent or delay cognitive impairment.

Clinical and Demographic Predictors of Conversion to Dementia in Mexican Elderly with Mild Cognitive Impairment.

Mild cognitive impairment (MCI) is considered a clinical stage between normal cognitive aging and dementia. The clinical course of MCI is heterogeneous, with a significant number of cases progressing to dementia or reverting back to normal. To determine the predictors of conversion from mild cognitive impairment to dementia among Mexican older adults. A sample of 175 persons underwent clinical and neuropsychological evaluation to establish mild cognitive impairment diagnosis. These patients were followed-up for a mean 3.5 years. Mean age was 81.7 (± 6.9) years, 57% were women, and mean education level was 9.5 (± 6.1) years. Sixty-one percent of mild cognitive impairment participants progressed to dementia. Multivariate Cox regression analysis showed that progression to dementia was associated with age (HR: 4.95; 95% CI: 1.96-12.46; p = 0.001), low education level (HR: 5.81; 95% CI: 1.90-7.78; p < 0.002), history of stroke (HR: 3.92; 95% CI: 1.37-11.16; p < 0.012) and cognitive decline (HR: 1.31; 95% CI: 1.18-1.45; p = 0.000). Age, poor education, cognitive decline, and a history of stroke were predictors of conversion to dementia. The identification and control of modifiable risk factors could influence conversion to dementia.

Natural course of mild cognitive impairment in Parkinson disease

To examine the incidence, progression, and reversion of mild cognitive impairment in patients with Parkinson disease (PD-MCI) over 5 years. A population-based cohort of patients with incident PD underwent repeated neuropsychological testing of attention, executive function, memory, and visuospatial abilities at baseline (n = 178), 1 year (n = 175), 3 years (n = 163), and 5 years (n = 150). Patients were classified as PD-MCI and diagnosed with dementia according to published criteria. Thirty-six patients (20.2%) fulfilled criteria for PD-MCI at baseline. Among those with normal cognition at baseline (n = 142), the cumulative incidence of PD-MCI was 9.9% after 1 year, 23.2% after 3 years, and 28.9% after 5 years of follow-up. Overall, 39.1% of patients with baseline or incident PD-MCI progressed to dementia during the 5-year study period. The conversion rate to dementia was 59.1% in patients with persistent PD-MCI at 1 year vs 7.2% in those with normal cognition during the first year (adjusted odds ratio 16.6, 95% confidence interval 5.1-54.7, p < 0.001). A total of 27.8% of patients with baseline PD-MCI and 24.2% of those with incident PD-MCI had reverted to normal cognition at study end, but the reversion rate decreased to 9.4% in those with persistent PD-MCI at 2 consecutive visits. Compared with cognitively normal patients, PD-MCI reverters within the first 3 years of follow-up were at increased risk of subsequently developing dementia (adjusted odds ratio 10.7, 95% confidence interval 1.5-78.5, p = 0.019). Early PD-MCI, regardless of persistence or reversion to normal cognition, has prognostic value for predicting dementia in patients with PD.

Amyloid-Beta Deposition is Associated with Increased Medial Temporal Lobe Activation during Memory Encoding in the Cognitively Normal Elderly

Much is unknown about changes that occur in the brain in the years preceding the cognitive and functional impairment associated with Alzheimer disease (AD). This period before mild cognitive impairment is present has been referred to as preclinical AD, and is thought to begin with amyloid-beta deposition and then progress to neurodegeneration and functional brain circuit alterations. Prior studies have shown that there is increased medial temporal lobe activation on functional magnetic resonance imaging (fMRI) early in the course of mild cognitive impairment. It is unknown, however, whether this altered fMRI activity precedes cognitive impairment. The purpose of this study is to address this question using Pittsburgh Compound-B (PiB) imaging and fMRI in a sample of cognitively normal older adults. Forty-four cognitively normal older adults underwent both PiB imaging and fMRI with a face-name memory task: 21 were classified as PiB(+) and 23 were PiB(-). Additionally, thorough cognitive and neuropsychological test batteries were administered outside the scanner. The main outcome measure in this study is fMRI activation in the medial temporal lobe during a face-name memory-encoding task. PiB(+) subjects showed higher fMRI activation during the memory task in the hippocampus relative to PiB(-) participants. The increased medial temporal lobe activation in preclinical AD, observed in this study, may serve as an early biomarker of neurodegeneration. Future studies are needed to clarify whether this functional biomarker can stratify AD risk among PiB(+) older adults.

Extrapyramidal Signs and Risk of Progression from Mild Cognitive Impairment to Dementia: A Clinical Research Center for Dementia of South Korea Study.

ObjectiveExtrapyramidal signs (EPS) are common in patients with mild cognitive impairment (MCI). However, few studies have assessed the effect of EPS on the clinical course of MCI. We aimed to evaluate whether patients with EPS show more frequent progression from MCI to Alzheimer's disease (AD) and to other types of dementia.MethodsParticipants (n=882) with MCI were recruited, and were followed for up to 5 years. The EPS positive group was defined by the presence of at least one EPS based on a focused neurologic examination at baseline.ResultsA total of 234 converted to dementia during the follow-up period. The risk of progression to AD was lower in the patients with EPS after adjusting for potential confounders [hazard ratio (HR)=0.70, 95% confidence interval (CI)=0.53–0.93, p=0.01]. In contrast, the patients with EPS had a six-fold elevated risk of progression to dementia other than AD (HR=6.33, 95%CI=2.30–17.39, p<0.001).ConclusionEPS in patients with MCI is a strong risk factor for progression of MCI to non-Alzheimer dementia. The careful neurologic examination for EPS in patients with MCI can yield important clinical information for prognosis.

A profile of The Clinical Course of Cognition and Comorbidity in Mild Cognitive Impairment and Dementia Study (The 4C study): two complementary longitudinal, clinical cohorts in the Netherlands.

BackgroundHeterogeneous disease trajectories of mild cognitive impairment (MCI) and dementia are frequently encountered in clinical practice, but there is still insufficient knowledge to understand the reasons and mechanisms causing this heterogeneity. In addition to correlates of the disorder, patient characteristics such as their health status, social environment, comorbidities and frailty may contribute to variability in trajectories over time. The current paper outlines the study design and the study population of and provides an overview of the data collected in the Clinical Course of Cognition and Comorbidity in Mild Cognitive Impairment (4C-MCI cohort, n = 315) and Dementia (4C-Dementia cohort, n = 331) Study. MethodsThe two complementary longitudinal cohorts part of the 4C study began enrolment in March 2010. Participants were prospectively recruited from three collaborating Dutch Alzheimer Centers, with three annual follow-up assessments after baseline. Extensive neuropsychological assessments, and detailed profiling of comorbidities, health and frailty at each follow up were the key features of the 4C study. As such, the 4C study was designed to study if and how patients’ comorbidities and frailty are associated with the course of MCI and dementia measured with a comprehensive and multidimensional set of outcomes including cognition, daily functioning, quality of life, behavioral disturbances, caregiver burden, institutionalization and death and whether the effects of medical health and frailty differ between MCI and dementia stages of cognitive disorders.ConclusionSampled in a clinical setting, the 4C study complements population-based studies on neurodegenerative disorders in terms of the type of assessment (e.g. comorbidity, frailty, and functional status were repeatedly assessed). The 4C study complements available clinical cohorts of MCI and dementia patients, because the exclusion criteria were kept to a minimum, to obtain a sample that is representative for the average patient visiting a memory clinic.

Occupational Attainment as Risk Factor forProgression from Mild Cognitive Impairment to Alzheimer's Disease: ACREDOS Study.

High occupational attainment has been known as a marker of cognitive reserve. Previous studies in the general population have shown that high occupational attainment is associated with reduced risk of Alzheimer's disease (AD). However, few studies have assessed the effect of occupational attainment on the clinical course of mild cognitive impairment (MCI). In this study, we evaluated whether individuals with high occupational attainment show more frequent progression from MCI to AD. Participants (n = 961) with MCI were recruited from a nationwide, hospital-based multi-center cohort, and were followed for up to 60 months (median: 17.64, interquartile range [12.36, 29.28]). We used Cox regression for competing risks to analyze the effect of occupational attainment on development of AD, treating dementia other than AD as a competing risk. Among the 961 individuals with MCI, a total of 280 (29.1%) converted to dementia during the follow-up period. The risk of progression to AD was higher in the individuals with high occupational attainment after controlling for potential confounders (hazard ratio = 1.83, 95% confidence interval = 1.25-2.69, p = 0.002). High occupational attainment in individuals with MCI is an independent risk factor for higher progression rate of MCI to AD. This result suggests that the protective effect of high occupational attainment against cognitive decline disappears in the MCI stage, and that careful assessment of occupational history can yield important clinical information for prognosis in individuals with MCI.

The Effects of Intellectual, Physical, and Social Activity on Further Prognosis in Mild Cognitive Impairment.

BackgroundOur goal was to specify the relationship between the level of activity (intellectual, physical, and social) in persons diagnosed with mild cognitive impairment (MCI) and the further progression of cognitive dysfunction.Material/MethodsWe examined 193 patients diagnosed with MCI (according to the criteria of the Working Group on Mild Cognitive Impairment) and under treatment at our Mental Disorders Clinic. It was assumed that these persons would remain under systematic psychiatric observation until dementia was diagnosed. The present study results from a seven-year observation period. The mini–mental state examination (MMSE), the Activity Scale (with the intellectual, physical, and social subscales), and the Instrumental Activities of Daily Living (IADL) scale were used to evaluate the participants’ status at baseline. The MMSE was re-administered after one year and again at the end of the observation (either upon diagnosis of dementia or after seven years). At each meeting with the participant, the clinical diagnosis was verified to determine if the patient had dementia or not. Of the 193 people initially qualified for the study, 75 were available for the final analysis.ResultsIt was found that there was no statistically significant difference in the baseline MMSE scores between the persons with stable MCI and the persons who had progressed to dementia. However, statistically significant differences in the level of activity at baseline on both the global IADL scale and the Activity Scale between those with stable MCI and those who had progressed to dementia were found. These differences were manifested in the IADL subscales for telephone use, shopping, transportation, and personal finances, and in the physical activity subscale.ConclusionsAn evaluation of intellectual, physical, and social activity can be useful in determining the prognosis for the future course of MCI.

Clinical Conversion or Reversion of Mild Cognitive Impairment in Community versus Hospital Based Studies: GDEMCIS (Gwangju Dementia and Mild Cognitive Impairment Study) and CREDOS (Clinical Research Center for Dementia of South Korea).

In keeping with increasing interest in dementia, few recent studies suggest that clinical course of mild cognitive impairment vary across different studies with hospital-based subjects showing higher rates of conversion than community-based subjects. The main objective of the present study was to assess whether the clinical conversion or reversion rates differ according to recruitment source. The baseline study subjects comprised of patients who were diagnosed with mild cognitive impairment in community-based GDEMCIS or hospital-based CREDOS. The two studies had nearly the same protocol and were performed over a similar period. We used propensity score matching for baseline comparability. After that, Cox proportional hazards regression analyses were conducted to estimate the hazard ratios and 95% confidence intervals of clinical conversion or reversion. Based on 89 GDEMCIS subjects, 1 : 4 propensity score matching was conducted and 356 CREDOS subjects were selected. After adjusting for covariates including baseline demographics, comorbidity, depression, disability, and neuropsychological result, Cox proportional hazard regression analysis for time to clinical conversion indicated that recruitment from hospital-based CREDOS exhibited hazard ratio of 2.13 (95% CI, 1.08-4.21), as compared to recruitment from community-based GDEMCIS. Similarly, Cox proportional hazard regression analysis for time to reversion indicated that recruitment from hospital-based CREDOS exhibited hazard ratio of 0.34 (95% CI, 0.20-0.59), as compared to recruitment from community-based GDEMCIS. The present study demonstrated that even after the matching process and adjustments for baseline covariates, recruitment source greatly affected the course of mild cognitive impairment.