Meditation's impact on default mode network and hippocampus in mild cognitive impairment: a pilot study

Those with high baseline stress levels are more likely to develop mild cognitive impairment (MCI) and Alzheimer's Disease (AD). While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations. Our objective was to conduct a "proof of concept" trial to determine whether Mindfulness Based Stress Reduction (MBSR) would improve DMN connectivity and reduce hippocampal atrophy among adults with MCI. 14 adults with MCI were randomized to MBSR vs. usual care and underwent resting state fMRI at baseline and follow-up. Seed based functional connectivity was applied using posterior cingulate cortex as seed. Brain morphometry analyses were performed using FreeSurfer. The results showed that after the intervention, MBSR participants had increased functional connectivity between the posterior cingulate cortex and bilateral medial prefrontal cortex and left hippocampus compared to controls. In addition, MBSR participants had trends of less bilateral hippocampal volume atrophy than control participants. These preliminary results indicate that in adults with MCI, MBSR may have a positive impact on the regions of the brain most related to MCI and AD. Further research with larger sample sizes and longer-follow-up are needed to further investigate the results from this pilot study.

THE QUICK DEMENTIA RATING SYSTEM (QDRS): A RAPID DEMENTIA STAGING TOOL

INTRODUCTION

Test the validity and reliability of the Quick Dementia Rating System (QDRS), a rapid dementia staging tool.

METHODS

The QDRS was tested in 267 patient-caregiver dyads compared with Clinical Dementia Ratings (CDR), neuropsychological testing, and gold standard measures of function, mood, and behavior. Psychometric properties including, item variability, floor and ceiling effects, concurrent and construct validity, and internal consistency were determined. The QDRS was used to derive an independent CDR and sum of boxes. Interscale reliability between QDRS and CDR was tested using intraclass correlation coefficients (ICC). Area under the receiver operator characteristic curves (AUC) tested discrimination properties of QDRS across CDR stages.

RESULTS

QDRS scores increased with higher CDR staging and poorer neuropsychological performance (p's <.001). The QDRS demonstrated low floor and ceiling effects; excellent known-groups validity across CDR stages (p's<.001); construct validity against cognitive, behavioral, and functional measures (p-value's:0.004 to <0.001); and reliability (Cronbach α: 0.86-0.93). The QDRS demonstrated differential scores across different dementia etiologies. The AUC for the QDRS was 0.911 (95%CI 0.86-0.96) and for the CDR-SB was 0.996 (95% CI: 0.99-1.0) demonstrating comparable ability to discriminate normal controls from dementia. The QDRS-generated CDR demonstrated excellent correspondence with the CDR (ICC=0.90) and sum-of-boxes (ICC=0.92).

DISCUSSION

The QDRS validly and reliably differentiates individuals with and without dementia and accurately stages dementia without extensive training or clinician input, and is highly correlated with our gold standard measures. The QDRS provides a rapid method to determine study eligibility; stage patients in clinical practice; and improve case ascertainment in population studies.

Prevalence of dementia in India: National and state estimates from a nationwide study

INTRODUCTION

Prior estimates of dementia prevalence in India were based on samples from selected communities, inadequately representing the national and state populations.

METHODS

From the Longitudinal Aging Study in India (LASI) we recruited a sample of adults ages 60+ and administered a rich battery of neuropsychological tests and an informant interview in 2018 through 2020. We obtained a clinical consensus rating of dementia status for a subsample (N = 2528), fitted a logistic model for dementia status on this subsample, and then imputed dementia status for all other LASI respondents aged 60+ (N = 28,949).

RESULTS

The estimated dementia prevalence for adults ages 60+ in India is 7.4%, with significant age and education gradients, sex and urban/rural differences, and cross-state variation.

DISCUSSION

An estimated 8.8 million Indians older than 60 years have dementia. The burden of dementia cases is unevenly distributed across states and subpopulations and may therefore require different levels of local planning and support.

HIGHLIGHTS

The estimated dementia prevalence for adults ages 60+ in India is 7.4%. About 8.8 million Indians older than 60 years live with dementia. Dementia is more prevalent among females than males and in rural than urban areas. Significant cross-state variation exists in dementia prevalence.

Screening for very mild subcortical vascular dementia patients aged 75 and above using the montreal cognitive assessment and mini-mental state examination in a community: the kurihara project

Aims

To examine the effectiveness of the Montreal Cognitive Assessment (MoCA) to screen people with mild cognitive impairment (MCI), to associate the MoCA score with the presence of infarction, and to detect the characteristics of people with very mild subcortical vascular dementia (vmSVD).

Methods

392 out of 886 community dwellers aged 75 years and above living in Kurihara, Northern Japan, agreed to participate in our study; 164 scored a Clinical Dementia Rating (CDR) of 0 (healthy), 184 scored a CDR of 0.5 (MCI) and 44 scored a CDR of 1+ (dementia). The participants scoring a CDR of 0.5 were divided into 2 subtypes: 37 had vmSVD and 147 had other types of dementia. The objective variables were the total MoCA, the MoCA subscale and the Mini-Mental State Examination (MMSE).

Results

There was a difference in the MoCA and MMSE scores between the 3 CDR groups. The MoCA score overlapped in participants with CDR 0 and 0.5. There were significant CDR effects, while there were no significant infarction effects for the MoCA and MMSE. vmSVD participants had lower scores on the total MoCA, the MoCA attention subscale and MMSE than healthy elderly people and participants with other types of dementia.

Conclusion

Our results suggested that MMSE performed rather well and that the MoCA is not superior to MMSE in MCI and vmSVD participants aged 75 and above in a community.

Serum Levels of α-Klotho Are Correlated with Cerebrospinal Fluid Levels and Predict Measures of Cognitive Function

BACKGROUND

α-klotho might play a role in neurodegenerative diseases.

OBJECTIVE

To determine levels of α-klotho and apoE in serum and cerebrospinal fluid (CSF) samples and their relationship with the Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR).

METHODS

All subjects were between age 39 to 83+ (n = 94). CDR and MMSE were administered to all participants. CSF was collected in the early afternoon by lumbar puncture.

RESULTS

Serum and CSF levels of α-klotho are positively correlated and both predict scores on the MMSE and CDR, regardless of sex or apoE4 status.

CONCLUSION

Our results demonstrate that α-klotho may be an important biomarker of cognitive health and neurodegeneration, and that relatively non-invasive sampling of α-klotho from serum is likely highly reflective of CSF levels.

A Cluster Randomized Controlled Trial of Nonpharmacological Interventions for Old-Old Subjects with a Clinical Dementia Rating of 0.5: The Kurihara Project

Background

Evidence as to the benefits of nonpharmacological interventions for the boundary state between normal aging and dementia [mild cognitive impairment or a Clinical Dementia Rating (CDR) of 0.5] remains weak due to a lack of positive controls.

Aims

To directly compare the effects of cognitive interventions (CI), physical activities (PA) and a group reminiscence approach (GRA), we conducted a pilot study on the basis of a cluster randomized controlled trial design.

Method

A total of 127 participants aged >74 years with a CDR of 0.5 were cluster randomized into three groups for CI, PA and GRA. The intervention lasted 12 weeks and consisted of weekly group sessions and home assignments. Mini-Mental State Examination (MMSE), Trail Making Test part A (TMT-A), word fluency (WF), 6-meter walk time and Quality of Life (QOL) Face Scale scores were evaluated as primary outcomes.

Results

Methodology-related benefits of CI and PA were found for MMSE scores and walk time, respectively. TMT-A, WF and QOL Face Scale scores improved irrespective of the methodologies used.

Conclusions

Our findings suggest that CI and PA may be beneficial to cognitive and physical abilities, respectively. Executive functions and QOL may improve irrespective of the intervention methodologies used.

Reliability and Validity of the Clinical Dementia Rating for Community-Living Elderly Subjects without an Informant

Background

The Clinical Dementia Rating (CDR) scale is widely used to assess cognitive impairment in Alzheimer's disease. It requires collateral information from a reliable informant who is not available in many instances. We adapted the original CDR scale for use with elderly subjects without an informant (CDR-NI) and evaluated its reliability and validity for assessing mild cognitive impairment (MCI) and dementia among community-dwelling elderly subjects.

Method

At two consecutive visits 1 week apart, nurses trained in CDR assessment interviewed, observed and rated cognitive and functional performance according to a protocol in 90 elderly subjects with suboptimal cognitive performance [Mini-Mental State Examination (MMSE) <26 and/or Montreal Cognitive Assessment (MOCA) <26] and without informants according to a protocol. CDR domains and global scores were assigned after the second visit based upon corroborative information from the subjects' responses to questions, role-play, and observed performance in specifically assigned tasks at home and within the community.

Results

The CDR-NI scores (0, 0.5, 1) showed good internal consistency (Crohnbach's α 0.83-0.84), inter-rater reliability (κ 0.77-1.00 for six domains and 0.95 for global rating) and test-retest reliability (κ 0.75-1.00 for six domains and 0.80 for global rating), good agreement (κ 0.79) with the clinical assessment status of MCI (n = 37) and dementia (n = 4) and significant differences in the mean scores for MMSE, MOCA and Instrumental Activities of Daily Living (ANOVA global p < 0.001).

Conclusion

Owing to the protocol of the interviews, assessments and structured observations gathered during the two visits, CDR-NI provides valid and reliable assessment of MCI and dementia in community-living elderly subjects without an informant.

Anterolateral entorhinal cortex thickness as a new biomarker for early detection of Alzheimer's disease

INTRODUCTION

Loss of entorhinal cortex (EC) layer II neurons represents the earliest Alzheimer's disease (AD) lesion in the brain. Research suggests differing functional roles between two EC subregions, the anterolateral EC (aLEC) and the posteromedial EC (pMEC).

METHODS

We use joint label fusion to obtain aLEC and pMEC cortical thickness measurements from serial magnetic resonance imaging scans of 775 ADNI-1 participants (219 healthy; 380 mild cognitive impairment; 176 AD) and use linear mixed-effects models to analyze longitudinal associations among cortical thickness, disease status, and cognitive measures.

RESULTS

Group status is reliably predicted by aLEC thickness, which also exhibits greater associations with cognitive outcomes than does pMEC thickness. Change in aLEC thickness is also associated with cerebrospinal fluid amyloid and tau levels.

DISCUSSION

Thinning of aLEC is a sensitive structural biomarker that changes over short durations in the course of AD and tracks disease severity-it is a strong candidate biomarker for detection of early AD.

Online Clinical Consensus Diagnosis of Dementia: Development and Validation

OBJECTIVES

To introduce cost-effective expert clinical diagnoses of dementia into population-based research using an online platform and to demonstrate their validity against in-person clinical assessment and diagnosis.

DESIGN

The online platform provides standardized data necessary for clinicians to rate participants on the Clinical Dementia Rating (CDR^® ). Using this platform, clinicians diagnosed 60 patients at a range of CDR levels at two clinical sites. The online consensus diagnosis was compared with in-person clinical consensus diagnosis.

SETTING

All India Institute of Medical Sciences (AIIMS), Delhi, and National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, India.

PARTICIPANTS

Thirty patients each at AIIMS and NIMHANS with equal numbers of patients previously independently rated in person by experts as CDR is 0 (cognitively normal), CDR is 0.5 (mild cognitive impairment), and CDR is 1 or greater (dementia).

MEASUREMENTS

Multiple clinicians independently rate each participant on each CDR domain using standardized data and expert clinical judgment. The overall summary CDR is calculated by algorithm. When there are discrepancies among clinician ratings, clinicians discuss the case through a virtual consensus conference and arrive at a consensus overall rating.

RESULTS

Online clinical consensus diagnosis based on standardized interview data provides consistent clinical diagnosis with in-person clinical assessment and consensus diagnosis (κ coefficient = 0.76).

CONCLUSION

A web-based clinical consensus platform built on the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India interview data is a cost-effective way to obtain reliable expert clinical judgments. A similar approach can be used for other epidemiological studies of dementia. J Am Geriatr Soc 68:S54-S59, 2020.

The effect of repetitive transcranial magnetic stimulation on cognitive impairment in Parkinson's disease with dementia: Pilot study

BACKGROUND

The exact mechanism of cognitive impairment in PD is not known. Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a possible treatment for cognitive impairment and to treat the motor symptoms in Parkinson's disease (PD) where its effects seem additive to those of dopaminergic medications.

OBJECTIVE

In this pilot study we investigated whether repeated sessions of rTMS have an effect on measures of cognitive impairment in patients with PD dementia.

METHODS

33 patients with PD dementia were randomly assigned sham or real rTMS (2000 pulses; 20 Hz; 90% RMT; 10 trains of 10 s with 25 s between each train) over the hand area of each motor cortex (5 min between hemispheres) for 10 days (5 days/week) followed by 5 booster sessions every month for 3 months. Assessments included the Unified Parkinson's Disease Rating Scale part III (UPDRS), Montreal Cognitive Assessment (MoCA); Mini Mental State Examination (MMSE), Clinical Dementia Rating Scale (CDR); Memory and Executive Screening (MES) and Instrumental activity of Daily Living (IADL). Event related potentials (P300) and cortical excitability were measured before treatment and after the last session.

RESULTS

There were no significant differences in the effects of rTMS between groups. Although rTMS improved motor function in the active group it had only a minor effect on two of the dementia rating scores (the MMSE and MoCA) but not the others (CDR and MES). There was also a reduction in the latency of the P300 in the active group.

CONCLUSIONS

rTMS over M1 is useful for motor function and may have a small positive effect on cognition. However, better approaches for the latter are necessary, may be require multisite rTMS to target both motor and frontal cortical region.

Anosognosia and Its Relation to Psychiatric Symptoms in Early-Onset Alzheimer Disease

BACKGROUND

We investigated differences in the prevalence of anosognosia and neuropsychiatric symptoms (NPSs) characteristics according to disease severity in patients with early-onset Alzheimer disease (EOAD).

METHODS

We recruited 616 patients with EOAD. We subdivided participants into 2 groups based on the presence or absence of anosognosia and then again by Clinical Dementia Rating (CDR) scale. We compared the differences in the Neuropsychiatric Inventory (NPI) scores according to anosognosia and disease severity.

RESULTS

The percentage of patients with anosognosia in each CDR group steadily increased as the CDR rating increased (CDR 0.5 8.6% vs CDR 1 13.6% vs CDR 2 26.2%). The NPI total score was significantly higher in patients with anosognosia in the CDR 0.5 and 1 groups; by contrast, it had no association in the CDR 2 group. Frontal lobe functions were associated with anosognosia only in the CDR 0.5 and 1 groups. After stratification by CDR, in the CDR 0.5 group, the prevalence of agitation ( P = .040) and appetite ( P = .013) was significantly higher in patients with anosognosia. In the CDR 1 group, patients with anosognosia had a significantly higher prevalence of delusions ( P = .032), hallucinations ( P = .048), and sleep disturbances ( P = .047). In the CDR 2 group, we found no statistical difference in the frequency of symptoms between patients with and without anosognosia.

CONCLUSION

These results confirm that the prevalence of anosognosia as well as the individual NPS and cognitive functions associated with it differ according to EOAD severity.

Cognitive and Neuropsychological Profiles in Alzheimer's Disease and Primary Age-Related Tauopathy and the Influence of Comorbid Neuropathologies

BACKGROUND

Alzheimer's disease neuropathologic change (ADNC) is defined by the progression of both hyperphosphorylated-tau (p-tau) and amyloid-β (Aβ) and is the most common underlying cause of dementia worldwide. Primary age-related tauopathy (PART), an Aβ-negative tauopathy largely confined to the medial temporal lobe, is increasingly being recognized as an entity separate from ADNC with diverging clinical, genetic, neuroanatomic, and radiologic profiles.

OBJECTIVE

The specific clinical correlates of PART are largely unknown; we aimed to identify cognitive and neuropsychological differences between PART, ADNC, and subjects with no tauopathy (NT).

METHODS

We compared 2,884 subjects with autopsy-confirmed intermediate-high stage ADNC to 208 subjects with definite PART (Braak stage I-IV, Thal phase 0, CERAD NP score "absent") and 178 NT subjects from the National Alzheimer's Coordinating Center dataset.

RESULTS

PART subjects were older than either ADNC or NT patients. The ADNC cohort had more frequent neuropathological comorbidities as well as APOE ɛ4 alleles than the PART or NT cohort, and less frequent APOE ɛ2 alleles than either group. Clinically, ADNC patients performed significantly worse than NT or PART subjects across cognitive measures, but PART subjects had selective deficits in measures of processing speed, executive function, and visuospatial function, although additional cognitive measures were further impaired in the presence of neuropathologic comorbidities. In isolated cases of PART with Braak stage III-IV, there are additional deficits in measures of language.

CONCLUSION

Overall, these findings demonstrate underlying cognitive features specifically associated with PART, and reinforce the concept that PART is a distinct entity from ADNC.

Decreased Physical Activity Associated with Executive Dysfunction Correlates with Cognitive Impairment among Older Adults in the Community: A Retrospective Analysis from the Kurihara Project

BACKGROUND/AIMS

No previous studies have explored the relationship between physical activity (PA) and executive dysfunction.

METHODS

We retrospectively evaluated the PA for 590 older participants in the Kurihara Project; 221 participants had a Clinical Dementia Rating (CDR) of 0 (healthy), 295 CDR 0.5 (very mild dementia), and 74 CDR 1+ (dementia).

RESULTS

In the complicated task, whether the motor intensity was high (e.g. farming) or low (e.g. shopping), PA exhibited an inverse relationship with the CDR level. By contrast, for simple tasks with high intensity (e.g. walking), no CDR group differences were noted. For PA with low intensity (e.g. cleaning), the CDR 1+ group exhibited decreased levels.

CONCLUSION

PA was related to the burden of executive function in patients with mild cognitive impairment; however, in patients with dementia, PA was related to both the burden of executive function and motor intensity.

Multiple markers contribute to risk of progression from normal to mild cognitive impairment

OBJECTIVE

To identify a parsimonious set of markers that optimally predicts subsequent clinical progression from normal to mild cognitive impairment (MCI).

METHODS

250 clinically normal adults (mean age = 73.6 years, SD = 6.0) from the Harvard Aging Brain Study were assessed at baseline on a wide set of markers, including magnetic resonance imaging markers of gray matter thickness and volume, white matter lesions, fractional anisotropy, resting state functional connectivity, positron emission tomography markers of glucose metabolism and β-amyloid (Aβ) burden, and a measure of vascular risk. Participants were also tested annually on a battery of clinical and cognitive tests (median follow-up = 5.0 years, SD = 1.66). We applied least absolute shrinkage and selection operator (LASSO) Cox models to determine the minimum set of non-redundant markers that predicts subsequent clinical progression from normal to MCI, adjusting for age, sex, and education.

RESULTS

23 participants (9.2%) progressed to MCI over the study period (mean years of follow-up to diagnosis = 3.96, SD = 1.89). Progression was predicted by several brain markers, including reduced entorhinal thickness (hazard ratio, HR = 1.73), greater Aβ burden (HR = 1.58), lower default network connectivity (HR = 1.42), and smaller hippocampal volume (HR = 1.30). When cognitive test scores were added to the model, the aforementioned neuroimaging markers remained significant and lower striatum volume as well as lower scores on baseline memory and processing speed tests additionally contributed to progression.

CONCLUSION

Among a large set of brain, vascular and cognitive markers, a subset of markers independently predicted progression from normal to MCI. These markers may enhance risk stratification by identifying clinically normal individuals who are most likely to develop clinical symptoms and would likely benefit most from therapeutic intervention.

The Progression of Alzheimer's Disease Can Be Assessed with a Short Version of the CERAD Neuropsychological Battery: The Kuopio ALSOVA Study

Background/Aims

Measuring and predicting Alzheimer's disease (AD) progression is important in order to adjust treatment and allocate care resources. We aimed to identify a combination of subtests from the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB) that best correlated with AD progression in follow-up as well as to predict AD progression.

Method

A total of 236 participants with very mild [Clinical Dementia Rating (CDR) = 0.5] or mild AD (CDR = 1.0) at baseline were followed up for 3 years. The CERAD-NB and Mini-Mental State Examination (MMSE) were used to assess cognition, and the CDR scale sum of boxes (CDR-sb) was employed to evaluate AD progression. Generalized estimating equations were used to develop models to predict and follow up disease progression.

Results

Performance declined on all CERAD-NB subtests. The ability of the separate subtests to distinguish between groups (baseline CDR = 0.5 or 1.0) diminished during follow-up. The best combination of subtests that explained 62% of CDR-sb variance in follow-up included verbal fluency, constructional praxis, the clock drawing test, and the MMSE. Baseline values of the same combination predicted 37% of the CDR-sb change.

Conclusion

A short version of the CERAD-NB subtests provides a promising and time-efficient alternative for measuring cognitive deterioration during AD follow-up. Although the initial signs of AD include memory difficulties, it may be useful to assess non-memory tasks in follow-up.

Microstructural damage of normal-appearing white matter in subcortical ischemic vascular dementia is associated with Montreal Cognitive Assessment scores

Objectives

This study was performed to determine whether multimodal biomarkers are more strongly associated with the Montreal Cognitive Assessment (MoCA) scores compared with the Mini-Mental State Examination (MMSE) scores, and whether they are correlated with the Clinical Dementia Rating (CDR) in patients with subcortical ischemic vascular dementia (SIVD).

Methods

Patients diagnosed with SIVD were enrolled. Peripheral blood hypersensitive C-reactive protein, white matter lesion volume (WMLV), fractional anisotropy (FA)/mean diffusivity (MD) of whole brain white matter (WBWM), and normal-appearing white matter (NAWM) were measured and correlated with MMSE, MoCA, and CDR scores.

Results

Bivariate analyses of data from 48 included patients revealed that both MoCA and MMSE were significantly associated with age, education, and FA of NAWM. Only MD of NAWM was correlated with MoCA scores. In partial correlation analysis adjusted for demographic and neuroimaging variables, MD/FA of NAWM and the MoCA scores were significantly correlated. FA/MD of NAWM had a modest trend toward a correlation with the CDR, but it was not significant.

Conclusions

In the patients with SIVD, FA/MD of NAWM were more strongly related to MoCA scores compared with MMSE scores.

Item response theory analysis of the Clinical Dementia Rating

INTRODUCTION

The Clinical Dementia Rating (CDR) is widely used in Alzheimer's disease research studies and has well established reliability and validity. To facilitate the development of an online, electronic CDR (eCDR) for more efficient clinical applications, this study aims to produce a shortened version of the CDR, and to develop the statistical model for automatic scoring.

METHODS

Item response theory (IRT) was used for item evaluation and model development. An automatic scoring algorithm was validated using existing CDR global and domain box scores as the reference standard.

RESULTS

Most CDR items discriminate well at mild and very mild levels of cognitive impairment. The bi-factor IRT model fits best and the shortened CDR still demonstrates very high classification accuracy (81%∼92%).

DISCUSSION

The shortened version of the CDR and the automatic scoring algorithm has established a good foundation for developing an eCDR and will ultimately improve the efficiency of cognitive assessment.

Progression from Prodromal Alzheimer's Disease to Mild Alzheimer's Disease Dementia in the Verubecestat APECS Study: Adjudicating Diagnostic Transitions

BACKGROUND

Delay of progression from prodromal Alzheimer's disease (AD) to dementia is an important outcome in AD trials. Centralized adjudication is intended to improve the consistency of dementia diagnosis but has not been scrutinized.

OBJECTIVE

To evaluate centralized adjudication for determining progression to dementia compared with Site Investigator opinion or change in Clinical Dementia Rating (CDR).

METHODS

We used data from the 2-year APECS trial of verubecestat versus placebo in 1,451 prodromal AD participants. Cases were triggered for central adjudication if: 1) the Site Investigator judged the participant had progressed to dementia, or 2) the participant's CDR sum-of-boxes score increased ≥2 points from baseline. Post-hoc analyses were performed on pooled treatment-group data to compare methods of assessing progression.

RESULTS

581/1,451 (40%) participants had changes triggering adjudication and most (83%) were confirmed as progression to dementia. Only 66% of those who met CDR criteria (regardless of whether they also met Site Investigator criteria) were adjudicated to have progressed to dementia and just 15% of those who met only CDR criteria were adjudicated to have progressed, representing 5% of progressors. In contrast, 99% of those who met Site Investigator criteria (regardless of whether they also met CDR criteria) were adjudicated to have progressed, and the same was true for those who met only Site Investigator criteria.

CONCLUSION

A positive Site Investigator opinion is an excellent predictor for a positive adjudication decision regarding onset of dementia. Conversely, sole use of CDR sum-of-boxes change ≥2 is inadequate. The benefit of centralized adjudication appears doubtful.

Features of Cerebral Small Vessel Disease Contributes to the Differential Diagnosis of Alzheimer's Disease

BACKGROUND

Cerebral small vessel disease (CSVD), which comprises the typical features of white matter hyperintensity (WMH) and Vichor-Robin spaces (VRSs) in the brain, is one of the leading causes of aging-related cognitive decline and, ultimately, contributes to the occurrence of dementia, including Alzheimer's disease (AD).

OBJECTIVE

To investigate whether CSVD imaging markers modify the pathological processes of AD and whether these markers improve AD diagnosis.

METHODS

208 participants were enrolled in the China Aging and Neurodegenerative Initiative (CANDI). Fluid AD biomarkers were detected using a single-molecule array, and cerebral small vessel dysfunction was determined using magnetic resonance imaging.

RESULTS

WMH contributed to AD pathology only within the NC and MCI groups (CDR ≤0.5), whereas VRSs had no effect on AD pathology. The associations between AD biomarkers and cognitive mental status were consistent with the presence of CSVD pathology. That is, within individuals without CSVD pathology, the MMSE scores were correlated with AD fluid biomarkers, except for plasma Aβ42 and Aβ40. Increased plasma p-Tau levels were associated with worse cognitive performance in individuals with WMH (β= -0.465, p = 0.0016) or VRSs (β= -0.352, p = 0.0257) pathology. Plasma AD biomarkers combined with CSVD markers showed high accuracy in diagnosing dementia.

CONCLUSION

Findings from this cross-sectional cohort study support the notion that CSVD is a risk factor for dementia and highlights that vascular pathology can promote AD biomarker levels, especially in the early course of the disease. Moreover, our results suggest that adding a vascular category to the ATN framework improves the diagnostic accuracy of AD.

Dementia in Essential Tremor: A Visual Record

Background

Research studies have shown an association between essential tremor (ET) and dementia, although dementia in ET is not often regarded as a clinically important issue.

Phenomenology Shown

We present three tangible visual records of patients with ET who have developed concurrent, comorbid dementia.

Educational Value

ET is a risk factor for dementia. This non-motor feature of the disease has substantial effects on the lives of patients and their families.

Intracranial internal carotid artery calcification is not predictive of future cognitive decline

Background

Intracranial internal carotid artery (ICA) calcification is a common incidental finding in non-contrast head CT. We evaluated the predictive value of ICAC (ICAC) for future risk of cognitive decline and compared the results with conventional imaging biomarkers of dementia.

Methods

In a retrospective observational cohort, we included 230 participants with a PET-CT scan within 18 months of a baseline clinical assessment and longitudinal imaging assessments. Intracranial ICAC was quantified on baseline CT scans using the Agatson calcium score, and the association between baseline ICA calcium scores and the risk of conversion from a CDR of zero in baseline to a persistent CDR > 0 at any follow-up visit, as well as longitudinal changes in cognitive scores, were evaluated through linear and mixed regression models. We also evaluated the association of conventional imaging biomarkers of dementia with longitudinal changes in cognitive scores and a potential indirect effect of ICAC on cognition through these biomarkers.

Results

Baseline ICA calcium score could not distinguish participants who converted to CDR > 0. ICA calcium score was also unable to predict longitudinal changes in cognitive scores, imaging biomarkers of small vessel disease such as white matter hyperintensities (WMH) volume, or AD such as hippocampal volume, AD cortical signature thickness, and amyloid burden. Severity of intracranial ICAC increased with age and in men. Higher WMH volume and amyloid burden as well as lower hippocampal volume and AD cortical signature thickness at baseline predicted lower Mini-Mental State Exam scores at longitudinal follow-up. Baseline ICAC was indirectly associated with longitudinal cognitive decline, fully mediated through WMH volume.

Conclusions

In elderly and preclinical AD populations, atherosclerosis of large intracranial vessels as demonstrated through ICAC is not directly associated with a future risk of cognitive impairment, or progression of imaging biomarkers of AD or small vessel disease.

Distinct medical and substance use histories associate with cognitive decline in Alzheimer's Disease

INTRODUCTION

Phenotype clustering reduces patient heterogeneity and could be useful when designing precision clinical trials. We hypothesized that the onset of early cognitive decline in patients would exhibit variance predicated on the clinical history documented prior to an Alzheimer's Disease (AD) diagnosis.

METHODS

Self-reported medical and substance use history (i.e., problem history) was used to cluster participants from the National Alzheimer's Coordinating Centers (NACC) into distinct subtypes. Linear mixed effects modeling was used to determine the effect of problem history subtype on cognitive decline over two years.

RESULTS

2754 individuals were partitioned into three subtypes: minimal (n = 1380), substance use (n = 1038), and cardiovascular (n = 336) subtypes. The cardiovascular problem history subtype had significantly worse cognitive decline over a two-year follow-up period (p = 0.013).

DISCUSSION

Our study highlights the need to account for problem history to reduce heterogeneity of outcomes in AD clinical trials.

Distinct medical and substance use histories associate with cognitive decline in Alzheimer's disease

INTRODUCTION

Phenotype clustering reduces patient heterogeneity and could be useful when designing precision clinical trials. We hypothesized that the onset of early cognitive decline in patients would exhibit variance predicated on the clinical history documented prior to an Alzheimer's disease (AD) diagnosis.

METHODS

Self-reported medical and substance use history (i.e., problem history) was used to cluster participants from the National Alzheimer's Coordinating Center (NACC) into distinct subtypes. Linear mixed effects modeling was used to determine the effect of problem history subtype on cognitive decline over 2 years.

RESULTS

Two thousand seven hundred fifty-four individuals were partitioned into three subtypes: minimal (n = 1380), substance use (n = 1038), and cardiovascular (n = 336). The cardiovascular problem history subtype had significantly worse cognitive decline over a 2 year follow-up period (p = 0.013).

DISCUSSION

Our study highlights the need to account for problem history to reduce heterogeneity of outcomes in AD clinical trials.

HIGHLIGHTS

Clinical data were used to identify subtypes of patients with Alzheimer's disease (AD) in the National Alzheimer's Coordinating Center dataset. Three problem history subtypes were found: minimal, substance use, and cardiovascular. The mean change in Clinical Dementia Rating Sum of Boxes (CDR-SB) was assessed over a 2 year follow-up. The cardiovascular subtype was associated with the worst cognitive decline. The magnitude of change in CDR-SB was similar to recent AD clinical trials.

Web-based Software for Real-time Simulation-assisted Trial Design in Alzheimer's Disease

Clinical trials for Alzheimer's Disease (AD) are necessarily designed in the presence of substantial quantitative uncertainty. Certain important aspects of this uncertainty can be mitigated by developing longitudinal models for AD progression and by using these models to simulate virtual trials and estimate operating characteristics (such as statistical power, the probability of stopping at an interim analysis, the probability of identifying the correct dose, etc.) as a function of candidate design features, such as inclusion / exclusion criteria. In this brief report we describe the development and deployment of a customized software solution that allows such simulation-based results to be generated "on the fly" in the context of a drug development team meeting. This solution leverages a number of recent practical advances in statistical and scientific computing that could be much more broadly leveraged to assure more quantitatively grounded trial designs in Alzheimer's Disease.

Association Between Executive Dysfunction-Related Activities of Daily Living Disability and Clinical Dementia Rating Domain Patterns in Patients With Vascular Dementia and Age-Matched Patients With Alzheimer's Dementia

OBJECTIVE

Although the Clinical Dementia Rating (CDR) scale was originally developed to stage Alzheimer's dementia (AD), it is now used globally for various types of dementia. The aim of this study was to investigate the characteristic pattern of CDR domains and its association with neuropsychological findings and activities of daily living (ADL) in patients with vascular dementia (VaD) and patients with AD.

METHODS

We recruited very mild to mild VaD and AD patients who were age-matched among the first visitors to a dementia clinic. All subjects underwent a standardized clinical interview, physical and neurological examinations, and laboratory tests, including brain magnetic resonance imaging, according to the protocol of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease assessment battery.

RESULTS

A total of 105 pairs of VaD and AD patients participated in this study. Although the adjusted scores on Korean version of the Mini-Mental State Examination were similar between the two groups, the VaD patients performed better on the Boston Naming Test, Word List Memory, Word List Recall, Word List Recognition, and Constructional Recall Test. However, the scores on global CDR, CDR sum of boxes, and ADL-related CDR domains were higher in VaD patients than in AD patients (p<0.001). The VaD patients also showed poor performances on the Disability Assessment for Dementia Scale, Frontal Assessment Battery, Executive Clock Drawing Task, and Stroop tests.

CONCLUSION

Despite similar general cognitive function and better memory function, patients with VaD tend to be staged as severer dementia on the CDR scale than patients with AD because of more impaired ADL associated with executive dysfunction.