ABSTRACT
INTRODUCTION: The contribution of neuropsychological assessments to risk assessment for incident dementia is underappreciated. METHODS: We analyzed neuropsychological testing results in dementia-free participants in the Atherosclerosis Risk in Communities (ARIC) study. We examined associations of index domain-specific neuropsychological test performance with incident dementia using cumulative incidence curves and Cox proportional hazards models. RESULTS: Among 5296 initially dementia-free participants (mean [standard deviation] age of 75.8 [5.1] years; 60.1% women, 22.2% Black) over a median follow-up of 7.9 years, the covariate-adjusted hazard ratio varied substantially depending on the pattern of domain-specific performance and age, in an orderly manner from single domain language abnormalities (lowest risk) to single domain executive or memory abnormalities, to multidomain abnormalities including memory (highest risk). DISCUSSION: By identifying normatively defined cognitive abnormalities by domains based on neuropsychological test performance, there is a conceptually orderly and age-sensitive spectrum of risk for incident dementia that provides valuable information about the likelihood of progression. HIGHLIGHTS: Domain-specific cognitive profiles carry enhanced prognostic value compared to mild cognitive impairment. Single-domain non-amnestic cognitive abnormalities have the most favorable prognosis. Multidomain amnestic abnormalities have the greatest risk for incident dementia. Patterns of domain-specific risks are similar by sex and race.
Subject(s)
Dementia , Neuropsychological Tests , Humans , Female , Male , Dementia/epidemiology , Dementia/diagnosis , Aged , Neuropsychological Tests/statistics & numerical data , Risk Assessment , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/diagnosis , Incidence , Risk Factors , Aged, 80 and over , Cognition Disorders/epidemiology , Cognition Disorders/diagnosis , Proportional Hazards ModelsABSTRACT
INTRODUCTION: Vascular contributions to cognitive impairment and dementia (VCID) represent a major factor in cognitive decline in older adults. The present study examined the relationship between cerebrovascular reactivity (CVR) measured by magnetic resonance imaging (MRI) and cognitive function in a multi-site study, using a predefined hypothesis. METHODS: We conducted the study in a total of three analysis sites and 263 subjects. Each site performed an identical CVR MRI procedure using 5% carbon dioxide inhalation. A global cognitive measure of Montreal Cognitive Assessment (MoCA) and an executive function measure of item response theory (IRT) score were used as outcomes. RESULTS: CVR and MoCA were positively associated, and this relationship was reproduced at all analysis sites. CVR was found to be positively associated with executive function. DISCUSSION: The predefined hypothesis on the association between CVR and a global cognitive score was validated in three independent analysis sites, providing support for CVR as a biomarker in VCID. HIGHLIGHTS: This study measured a novel functional index of small arteries referred to as cerebrovascular reactivity (CVR). CVR was positively associated with global cognition in older adults. This finding was observed in three independent cohorts at three sites. Our statistical analysis plan was predefined before beginning data collection.
ABSTRACT
OBJECTIVE: Blood-brain barrier (BBB) breakdown has been suggested to be an early biomarker in human cognitive impairment. However, the relationship between BBB breakdown and brain pathology, most commonly Alzheimer disease (AD) and vascular disease, is still poorly understood. The present study measured human BBB function in mild cognitive impairment (MCI) patients on 2 molecular scales, specifically BBB's permeability to water and albumin molecules. METHODS: Fifty-five elderly participants were enrolled, including 33 MCI patients and 22 controls. BBB permeability to water was measured with a new magnetic resonance imaging technique, water extraction with phase contrast arterial spin tagging. BBB permeability to albumin was determined using cerebrospinal fluid (CSF)/serum albumin ratio. Cognitive performance was assessed by domain-specific composite scores. AD pathology (including CSF Aß and ptau) and vascular risk factors were examined. RESULTS: Compared to cognitively normal subjects, BBB in MCI patients manifested an increased permeability to small molecules such as water but was no more permeable to large molecules such as albumin. BBB permeability to water was found to be related to AD markers of CSF Aß and ptau. On the other hand, BBB permeability to albumin was found to be related to vascular risk factors, especially hypercholesterolemia, but was not related to AD pathology. BBB permeability to small molecules, but not to large molecules, was found to be predictive of cognitive function. INTERPRETATION: These findings provide early evidence that BBB breakdown is related to both AD and vascular risks, but their effects can be differentiated by spatial scales. BBB permeability to small molecules has a greater impact on cognitive performance. ANN NEUROL 2021;90:227-238.
Subject(s)
Alzheimer Disease/cerebrospinal fluid , Blood-Brain Barrier/metabolism , Capillary Permeability/physiology , Cognitive Dysfunction/cerebrospinal fluid , Vascular Diseases/cerebrospinal fluid , Aged , Alzheimer Disease/diagnostic imaging , Amyloid beta-Peptides/cerebrospinal fluid , Blood-Brain Barrier/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Cross-Sectional Studies , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Peptide Fragments/cerebrospinal fluid , Serum Albumin, Human/cerebrospinal fluid , Vascular Diseases/diagnostic imaging , tau Proteins/cerebrospinal fluidABSTRACT
AIM: To determine whether antihypertensive medication (AHM) acting through the renin angiotensin system (RAS-AHM), compared with other AHM, can mitigate effects on cognitive function and risk for impairment in a population with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: This secondary analysis of the randomized controlled Action for Health in Diabetes (Look AHEAD) study included 712 community-dwelling participants who were followed over 15 years. Logistic regression was used to relate RAS-AHM use to cognitive impairment, and linear regression was used to relate RAS-AHM use to domain-specific cognitive function after adjusting for potential confounders. RESULTS: A total of 563 individuals reported RAS-AHM use and 149 reported other-AHM use during the study. RAS-AHM users have college or higher education (53%), had higher baseline glycated haemoglobin (57 mmol/mol), and reported higher diabetes medication use (86%), while other-AHM users were more likely to be White (72%), obese (25%) and to have cardiovascular history (19%). RAS-AHM use was not associated with a reduced risk of dementia compared with other-AHM use. We did observe better executive function (Trail Making Test, part B, P < 0.04), processing speed (Digit Symbol Substitution Test, P < 0.004), verbal memory (Rey Auditory Verbal Learning Test-delayed recall, P < 0.005), and composite score (P < 0.008) among RAS-AHM users compared with other-AHM users. CONCLUSION: In this sample of adults with T2DM, free of dementia at baseline, we observed a slower decline in processing speed, executive function, verbal memory, and composite score among RAS-AHM users.
Subject(s)
Cognitive Dysfunction , Dementia , Diabetes Mellitus, Type 2 , Humans , Antihypertensive Agents/therapeutic use , Renin-Angiotensin System , Overweight/complications , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/psychology , Cognition , Obesity/complications , Obesity/drug therapy , Cognitive Dysfunction/drug therapy , Cognitive Dysfunction/prevention & controlABSTRACT
Neuropsychiatric symptoms (NPS) in persons with dementia (PWD) are common and can lead to poor outcomes, such as institutionalization and mortality, and may be exacerbated by sensory loss. Hearing loss is also highly prevalent among older adults, including PWD. OBJECTIVE: This study investigated the association between hearing loss and NPS among community- dwelling patients from a tertiary memory care center. DESIGN, SETTING, AND PARTICIPANTS: Participants of this cross-sectional study were patients followed at the Johns Hopkins Memory and Alzheimer's Treatment Center who underwent audiometric testing during routine clinical practice between October 2014 and January 2017. OUTCOME MEASUREMENTS: Included measures were scores on the Neuropsychiatric Inventory-Questionnaire and the Cornell Scale for Depression in Dementia. RESULTS: Participants (nâ¯=â¯101) were on average 76 years old, mostly female and white, and had a mean Mini-Mental State Examination score of 23. We observed a positive association between audiometric hearing loss and the number of NPS (bâ¯=â¯0.7 per 10 dB; 95% confidence interval [CI]: 0.2, 1.1; tâ¯=â¯2.86; pâ¯=â¯0.01; dfâ¯=â¯85), NPS severity (bâ¯=â¯1.3 per 10 dB; 95% CI: 0.4, 2.5; tâ¯=â¯2.13; pâ¯=â¯0.04; dfâ¯=â¯80), and depressive symptom severity (bâ¯=â¯1.5 per 10 dB; 95% CI: 0.4, 2.5; tâ¯=â¯2.83; pâ¯=â¯0.01; dfâ¯=â¯89) after adjustment for demographic and clinical characteristics. Additionally, the use of hearing aids was inversely associated with the number of NPS (bâ¯=â¯-2.09; 95% CI -3.44, -0.75; tâ¯=â¯-3.10; pâ¯=â¯0.003; dfâ¯=â¯85), NPS severity (bâ¯=â¯-3.82; 95% CI -7.19, -0.45; tâ¯=â¯-2.26; pâ¯=â¯0.03; dfâ¯=â¯80), and depressive symptom severity (bâ¯=â¯-2.94; 95% CI: -5.93, 0.06; tâ¯=â¯1.70; pâ¯=â¯0.05; dfâ¯=â¯89). CONCLUSION: Among patients at a memory clinic, increasing severity of hearing loss was associated with a greater number of NPS, more severe NPS, and more severe depressive symptoms, while hearing aid use was associated with fewer NPS, lower severity, and less severe depressive symptoms. Identifying and addressing hearing loss may be a promising, low-risk, non-pharmacological intervention in preventing and treating NPS.
Subject(s)
Cognitive Dysfunction , Hearing Aids , Hearing Loss , Aged , Cognitive Dysfunction/complications , Cognitive Dysfunction/epidemiology , Cross-Sectional Studies , Female , Hearing Loss/complications , Hearing Loss/epidemiology , Humans , Male , Neuropsychological TestsABSTRACT
INTRODUCTION: Weight loss and increased physical activity interventions are commonly recommended for individuals with type 2 diabetes (T2D) and overweight or obesity. We examined the impact of randomization to an intensive lifestyle intervention (ILI) on trajectories of cognitive function over 10 years in a cohort of participants in a randomized clinical trial who had T2D and overweight/obesity at baseline. METHODS: Participants aged 45-76 years were enrolled in 2001-2004 and were randomized to the ILI or a diabetes support and education (DSE) condition. Cognitive function was assessed in 3,938 participants at up to 4 time points 8-18 years after randomization. General linear mixed effects models examined cognitive trajectories over time. Subgroup analyses focused on sex, individuals with baseline body mass index >30, those carrying the APOE ε4 allele, and those with a baseline history of cardiovascular disease (CVD). RESULTS: Overall, there were no differences in the rate of cognitive decline by intervention arm. Subgroup analyses showed that participants who had a baseline history of CVD and were randomized to the ILI arm of the study performed significantly worse on the Stroop Color Word Test than those in the DSE arm. DISCUSSION/CONCLUSIONS: The ILI did not result in preserved cognitive function or slower rates of cognitive decline in this cohort of individuals who had T2D and were overweight or obese at baseline.
Subject(s)
Diabetes Mellitus, Type 2 , Overweight , Cognition , Diabetes Mellitus, Type 2/therapy , Humans , Life Style , Obesity/therapy , Overweight/therapyABSTRACT
OBJECTIVE: To assess the predictive value of common measures validated to predict falls in other geriatric populations in patients presenting with suspected Normal Pressure Hydrocephalus (NPH). METHODS: One hundred ninety-five patients over the age of 60 who received the Fall Risk Questionnaire were retrospectively recruited from the CSF Disorders clinic within the departments of Neurosurgery and Neurology. Multiple logistic regression was used to create a model to predict falls for patients with suspected NPH using common measures: Timed Up & Go, Dual Timed Up & Go, 10 Meter Walk, MiniBESTest, 6-Minute Walk, Lower Extremity Function (Mobility), Fall Risk Questionnaire, and Functional Activities Questionnaire. RESULTS: The Fall Risk Questionnaire and age were shown to be the best predictors of falls. The model was 95.92% (Positive predictive value: 83.93%) sensitive and 47.92% specific (Negative predictive value: 77.78%). CONCLUSION: Patients presenting with suspected NPH are at an increased fall risk, 75% of the total patients and 89% of patients who responded to a temporary drain of CSF had at least one fall in the past 6 months. The Fall Risk Questionnaire and age were shown to be predictive of falls for patients with suspected NPH. The preliminary evidence indicates measures that have been validated to assess fall risk in other populations may not be valid for patients presenting with suspected NPH.
Subject(s)
Accidental Falls , Exercise Test/methods , Hydrocephalus, Normal Pressure/complications , Surveys and Questionnaires , Aged , Aged, 80 and over , Female , Gait , Humans , Logistic Models , Male , Predictive Value of Tests , Retrospective Studies , Time and Motion StudiesABSTRACT
Precision medicine, also known as personalized medicine, is concerned with finding the right treatment for the right patient at the right time. It is a way of thinking focused on parsing heterogeneity ultimately down to the level of the individual. Its main mission is to identify characteristics of heterogeneous clinical conditions so as to target tailored therapies to individuals. Precision Medicine however is not an agnostic collection of all manner of clinical, genetic and other biologic data in select cohorts. This is an important point. Simply collecting as much information as possible on individuals without applying this way of thinking should not be considered Precision Medicine.
Subject(s)
Alzheimer Disease , Precision Medicine , Alzheimer Disease/diagnosis , Alzheimer Disease/drug therapy , Alzheimer Disease/genetics , HumansABSTRACT
The concept of vascular contributions to cognitive impairment and dementia (VCID) derives from more than two decades of research indicating that (1) most older individuals with cognitive impairment have post mortem evidence of multiple contributing pathologies and (2) along with the preeminent role of Alzheimer's disease (AD) pathology, cerebrovascular disease accounts for a substantial proportion of this contribution. Contributing cerebrovascular processes include both overt strokes caused by etiologies such as large vessel occlusion, cardioembolism, and embolic infarcts of unknown source, and frequently asymptomatic brain injuries caused by diseases of the small cerebral vessels. Cerebral small vessel diseases such as arteriolosclerosis and cerebral amyloid angiopathy, when present at moderate or greater pathologic severity, are independently associated with worse cognitive performance and greater likelihood of dementia, particularly in combination with AD and other neurodegenerative pathologies. Based on this evidence, the US National Alzheimer's Project Act explicitly authorized accelerated research in vascular and mixed dementia along with frontotemporal and Lewy body dementia and AD itself. Biomarker development has been consistently identified as a key step toward translating scientific advances in VCID into effective prevention and treatment strategies. Validated biomarkers can serve a range of purposes in trials of candidate interventions, including (1) identifying individuals at increased VCID risk, (2) diagnosing the presence of cerebral small vessel disease or specific small vessel pathologies, (3) stratifying study participants according to their prognosis for VCID progression or treatment response, (4) demonstrating an intervention's target engagement or pharmacodynamic mechanism of action, and (5) monitoring disease progression during treatment. Effective biomarkers allow academic and industry investigators to advance promising interventions at early stages of development and discard interventions with low success likelihood. The MarkVCID consortium was formed in 2016 with the goal of developing and validating fluid- and imaging-based biomarkers for the cerebral small vessel diseases associated with VCID. MarkVCID consists of seven project sites and a central coordinating center, working with the National Institute of Neurologic Diseases and Stroke and National Institute on Aging under cooperative agreements. Through an internal selection process, MarkVCID has identified a panel of 11 candidate biomarker "kits" (consisting of the biomarker measure and the clinical and cognitive data used to validate it) and established a range of harmonized procedures and protocols for participant enrollment, clinical and cognitive evaluation, collection and handling of fluid samples, acquisition of neuroimaging studies, and biomarker validation. The overarching goal of these protocols is to generate rigorous validating data that could be used by investigators throughout the research community in selecting and applying biomarkers to multi-site VCID trials. Key features of MarkVCID participant enrollment, clinical/cognitive testing, and fluid biomarker procedures are summarized here, with full details in the following text, tables, and supplemental material, and a description of the MarkVCID imaging biomarker procedures in a companion paper, "MarkVCID Cerebral small vessel consortium: II. Neuroimaging protocols." The procedures described here address a range of challenges in MarkVCID's design, notably: (1) acquiring all data under informed consent and enrollment procedures that allow unlimited sharing and open-ended analyses without compromising participant privacy rights; (2) acquiring the data in a sufficiently wide range of study participants to allow assessment of candidate biomarkers across the various patient groups who might ultimately be targeted in VCID clinical trials; (3) defining a common dataset of clinical and cognitive elements that contains all the key outcome markers and covariates for VCID studies and is realistically obtainable during a practical study visit; (4) instituting best fluid-handling practices for minimizing avoidable sources of variability; and (5) establishing rigorous procedures for testing the reliability of candidate fluid-based biomarkers across replicates, assay runs, sites, and time intervals (collectively defined as the biomarker's instrumental validity). Participant Enrollment Project sites enroll diverse study cohorts using site-specific inclusion and exclusion criteria so as to provide generalizable validation data across a range of cognitive statuses, risk factor profiles, small vessel disease severities, and racial/ethnic characteristics representative of the diverse patient groups that might be enrolled in a future VCID trial. MarkVCID project sites include both prospectively enrolling centers and centers providing extant data and samples from preexisting community- and population-based studies. With approval of local institutional review boards, all sites incorporate MarkVCID consensus language into their study documents and informed consent agreements. The consensus language asks prospectively enrolled participants to consent to unrestricted access to their data and samples for research analysis within and outside MarkVCID. The data are transferred and stored as a de-identified dataset as defined by the Health Insurance Portability and Accountability Act Privacy Rule. Similar human subject protection and informed consent language serve as the basis for MarkVCID Research Agreements that act as contracts and data/biospecimen sharing agreements across the consortium. Clinical and Cognitive Data Clinical and cognitive data are collected across prospectively enrolling project sites using common MarkVCID instruments. The clinical data elements are modified from study protocols already in use such as the Alzheimer's Disease Center program Uniform Data Set Version 3 (UDS3), with additional focus on VCID-related items such as prior stroke and cardiovascular disease, vascular risk factors, focal neurologic findings, and blood testing for vascular risk markers and kidney function including hemoglobin A1c, cholesterol subtypes, triglycerides, and creatinine. Cognitive assessments and rating instruments include the Clinical Dementia Rating Scale, Geriatric Depression Scale, and most of the UDS3 neuropsychological battery. The cognitive testing requires ≈60 to 90 minutes. Study staff at the prospectively recruiting sites undergo formalized training in all measures and review of their first three UDS3 administrations by the coordinating center. Collection and Handling of Fluid Samples Fluid sample types collected for MarkVCID biomarker kits are serum, ethylenediaminetetraacetic acid-plasma, platelet-poor plasma, and cerebrospinal fluid (CSF) with additional collection of packed cells to allow future DNA extraction and analyses. MarkVCID fluid guidelines to minimize variability include fasting morning fluid collections, rapid processing, standardized handling and storage, and avoidance of CSF contact with polystyrene. Instrumental Validation for Fluid-Based Biomarkers Instrumental validation of MarkVCID fluid-based biomarkers is operationally defined as determination of intra-plate and inter-plate repeatability, inter-site reproducibility, and test-retest repeatability. MarkVCID study participants both with and without advanced small vessel disease are selected for these determinations to assess instrumental validity across the full biomarker assay range. Intra- and inter-plate repeatability is determined by repeat assays of single split fluid samples performed at individual sites. Inter-site reproducibility is determined by assays of split samples distributed to multiple sites. Test-retest repeatability is determined by assay of three samples acquired from the same individual, collected at least 5 days apart over a 30-day period and assayed on a single plate. The MarkVCID protocols are designed to allow direct translation of the biomarker validation results to multicenter trials. They also provide a template for outside groups to perform analyses using identical methods and therefore allow direct comparison of results across studies and centers. All MarkVCID protocols are available to the biomedical community and intended to be shared. In addition to the instrumental validation procedures described here, each of the MarkVCID kits will undergo biological validation to determine whether the candidate biomarker measures important aspects of VCID such as cognitive function. Analytic methods and results of these validation studies for the 11 MarkVCID biomarker kits will be published separately. The results of this rigorous validation process will ultimately determine each kit's potential usefulness for multicenter interventional trials aimed at preventing or treating small vessel disease related VCID.
Subject(s)
Biomarkers , Cerebral Small Vessel Diseases/diagnosis , Cognitive Dysfunction/diagnosis , Patient Selection , Research Design , Aged , Dementia/etiology , Disease Progression , Female , Humans , Information Dissemination , Male , Neuropsychological Tests , Stroke/etiologyABSTRACT
Cerebrovascular reactivity (CVR), an index of brain vessel's dilatory capacity, is typically measured using hypercapnic gas inhalation or breath-holding as a vasoactive challenge. However, these methods require considerable subject cooperation and could be challenging in clinical studies. More recently, there have been attempts to use resting-state BOLD data to map CVR by utilizing spontaneous changes in breathing pattern. However, in subjects who have small fluctuations in their spontaneous breathing pattern, the CVR results could be noisy and unreliable. In this study, we aim to develop a new method for CVR mapping that does not require gas-inhalation yet provides substantially higher sensitivity than resting-state CVR mapping. This new method is largely based on resting-state scan, but introduces intermittent modulation of breathing pattern in the subject to enhance fluctuations in their end-tidal CO2 (EtCO2) level. Here we examined the comfort level, sensitivity, and accuracy of this method in two studies. First, in 8 healthy young subjects, we developed the intermittent breath-modulation method using two different modulation frequencies, 6 âs per breath and 12 âs per breath, respectively, and compared the results to three existing CVR methods, specifically hypercapnic gas inhalation, breath-holding, and resting-state. Our results showed that the comfort level of the 6-s breath-modulation method was significantly higher than breath-holding (p â= â0.007) and CO2-inhalation (p â= â0.015) methods, while not different from the resting-state, i.e. free breathing method (p â= â0.52). When comparing the sensitivity of CVR methods, the breath-modulation methods revealed higher Z-statistics compared to the resting-state scan (p â< â0.008) and was comparable to breath-holding results. Next, we tested the feasibility of breath-modulation CVR mapping (6 âs per breath) in 21 cognitively normal elderly participants and compared quantitative CVR values to that obtained with the CO2-inhalation method. Whole-brain CVR was found to be 0.150 â± â0.055 and 0.154 â± â0.032 %ΔBOLD/mmHg for the breath-modulation and CO2-inhalation method, respectively, with a significant correlation between them (y â= â0.97x, p â= â0.007). CVR mapping with intermittent breath modulation may be a useful method that combines the advantages of resting-state and CO2-inhalation based approaches.
Subject(s)
Brain Mapping/methods , Brain/blood supply , Brain/physiology , Cerebrovascular Circulation/physiology , Magnetic Resonance Imaging , Respiration , Adult , Brain/diagnostic imaging , Breath Holding , Female , Humans , Hypercapnia/physiopathology , Male , Young AdultABSTRACT
BACKGROUND: Alzheimer's disease and vascular cognitive impairment (VCI), as well as their concurrence, represent the most common types of cognitive dysfunction. Treatment strategies for these two conditions are quite different; however, there exists a considerable overlap in their clinical manifestations, and most biomarkers reveal similar abnormalities between these two conditions. PURPOSE: To evaluate the potential of cerebral oxygen extraction fraction (OEF) as a biomarker for differential diagnosis of Alzheimer's disease and VCI. We hypothesized that in Alzheimer's disease OEF will be reduced (decreased oxygen consumption due to decreased neural activity), while in vascular diseases OEF will be elevated (increased oxygen extraction due to abnormally decreased blood flow). STUDY TYPE: Prospective cross-sectional. POPULATION: Sixty-five subjects aged 52-89 years, including 33 mild cognitive impairment (MCI), 7 dementia, and 25 cognitively normal subjects. FIELD STRENGTH/SEQUENCE: 3T T2 -relaxation-under-spin-tagging (TRUST) and fluid-attenuated inversion recovery imaging (FLAIR). ASSESSMENT: OEF, consensus diagnoses of cognitive impairment, vascular risk factors (such as hypertension, hypercholesterolemia, diabetes, smoking, and obesity), cognitive assessments, and cerebrospinal fluid concentration of amyloid and tau were assessed. STATISTICAL TESTS: Multiple linear regression analyses of OEF with diagnostic category (normal, MCI, or dementia), vascular risks, cognitive performance, amyloid and tau pathology. RESULTS: When evaluating the entire group, OEF was found to be lower with more severe cognitive impairment (ß = -2.70 ± 1.15, T = -2.34, P = 0.02), but was higher with greater vascular risk factors (ß = 1.36 ± 0.55, T = 2.48, P = 0.02). Further investigation of the subgroup of participants with low vascular risks (N = 44) revealed that lower OEF was associated with worse cognitive performance (ß = 0.04 ± 0.01, T = 3.27, P = 0.002) and greater amyloid burden (ß = 92.12 ± 41.23, T = 2.23, P = 0.03). Among cognitively impaired individuals (N = 40), higher OEF was associated with greater vascular risk factors (ß = 2.19 ± 0.71, T = 3.08, P = 0.004). DATA CONCLUSION: These findings suggest that OEF is differentially affected by Alzheimer's disease and VCI pathology and may be useful in etiology-based diagnosis of cognitive impairment. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 3 J. MAGN. RESON. IMAGING 2020;52:1829-1837.
Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Vascular Diseases , Aged , Aged, 80 and over , Alzheimer Disease/diagnostic imaging , Biomarkers , Brain/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Cross-Sectional Studies , Humans , Middle Aged , Oxygen , Prospective Studies , Vascular Diseases/diagnostic imagingABSTRACT
OBJECTIVE: To define the association between late-onset epilepsy (LOE) and 25-year change in cognitive performance. METHODS: The Atherosclerosis Risk in Communities (ARIC) study is a multicenter longitudinal cohort study with participants from four U.S. communities. From linked Medicare claims, we identified cases of LOE, defined as ≥2 seizure-related diagnostic codes starting at age ≥67. The ARIC cohort underwent evaluation with in-person visits at intervals of 3-15 years. Cognition was evaluated 4 times over >25 years (including before the onset of seizures) using the Delayed Word Recall Test (DWRT), Digit Symbol Substitution Test (DSST), and Word Fluency Test (WFT); a global z-score was also calculated. We compared the longitudinal cognitive changes of participants with and without LOE, adjusting for demographics and LOE risk factors. RESULTS: From 8033 ARIC participants with midlife cognitive testing and Medicare claims data available (4523 [56%] female, 1392 [17%] Black), we identified 585 cases of LOE. The rate of cognitive decline was increased on all measures in the participants who developed LOE compared to those without LOE. On the measure of global cognition, participants with LOE declined by -0.43 z-score points more over 25 years than did participants without epilepsy (95% confidence interval [CI] -0.59 to -0.27). Prior to the onset of seizures, cognitive decline was more rapid on the DWRT, DSST, and global z-scores in those who would later develop LOE than it was in non-LOE participants. Results were similar after excluding data from participants with dementia. SIGNIFICANCE: Global cognition, verbal memory, executive function, and word fluency declined faster over time in persons developing LOE than without LOE. Declines in cognition preceding LOE suggest these are linked; it will be important to investigate causes for midlife cognitive declines associated with LOE.
Subject(s)
Cognitive Dysfunction/psychology , Epilepsy/psychology , Black or African American , Case-Control Studies , Cognition , Cognitive Dysfunction/physiopathology , Epilepsy/physiopathology , Executive Function , Female , Humans , Late Onset Disorders/physiopathology , Late Onset Disorders/psychology , Longitudinal Studies , Male , Memory , Middle Aged , Neuropsychological Tests , White PeopleABSTRACT
BACKGROUND: Presently, for patients presenting with suspected Normal Pressure Hydrocephalus (NPH) who undergo temporary drainage of cerebrospinal fluid (CSF) there is no defined model to differentiate chance improvement form clinical significance change at the individual patient level. To address this lack of information we computed standard regression based clinical change models for the 10 Meter Walk Test, Timed Up & Go, Dual Timed Up & Go, 6-Minute Walk Test, Mini-Balance Evaluation Systems Test, Montreal Cognitive Assessment, and Symbol Digit Modalities using data from patients with suspected NPH that underwent temporary drainage of CSF. These clinically significant change modes can classify clinically significant improvement following temporary drainage of CSF at the individual patient level. This allows for physicians to differentiate a clinically significant improvement in symptoms from chance improvement. METHODS: Data was collected from 323 patients, over the age of 60, with suspected NPH that underwent temporary drainage of CSF with corresponding gait and cognitive testing. McSweeney Standardized Regression Based Clinical Change Models were computed for standard gait and cognitive measures: Timed Up & Go, Dual Timed Up & Go, 10 Meter Walk Test, MiniBESTest, 6-Minute Walk Test, Montreal Cognitive Assessment, and Symbol Digit Modalities Test. To assess the discriminate validity of the measures we used correlations, Chi2, and regression analyses. RESULTS: The clinical change models explained 69-91.8% of the variability in post-drain performance (p < 0.001). As patient scores became more impaired, the percent change required for improvement to be clinically significant increased for all measures. We found that the measures were not discriminate, the Timed Up & Go was highly related to the 10 Meter Walk Test (r = 0.85, R2 = 0.769-0.738, p < 0.001), MiniBESTest (r = - 0.67, R2 = 0.589-0.734, p < 0.001), and 6 Minute Walk Test (r = - 0.77, R2 = 0.71-0.734, p < 0.001). CONCLUSION: Standardized Regression Based Clinically Significant Change Models allow for physicians to use an evidence-based approach to differentiate clinically significant change from chance improvement at the individual patient level. The Timed Up & Go was shown to be predictive of detailed measures of gait velocity, balance, and endurance.
Subject(s)
Cerebrospinal Fluid Shunts , Gait , Hydrocephalus, Normal Pressure/therapy , Aged , Aged, 80 and over , Drainage , Female , Humans , Male , Neuropsychological Tests , Retrospective StudiesABSTRACT
INTRODUCTION: Type 2 diabetes mellitus and obesity may increase risks for cognitive decline as individuals age. It is unknown whether this results in different prevalences of cognitive impairment for women and men. METHODS: The Action for Health in Diabetes, a randomized controlled clinical trial of a 10-year intensive lifestyle intervention, adjudicated cases of cross-sectional cognitive impairment (mild cognitive impairment or dementia) 10-13 years after enrollment in 3802 individuals (61% women). RESULTS: The cross-sectional prevalences of cognitive impairment were 8.3% (women) and 14.8% (men): adjusted odds ratio 0.55, 95% confidence interval [0.43, 0.71], P < .001. Demographic, clinical, and lifestyle risk factors varied between women and men but did not account for this difference, which was limited to individuals without apolipoprotein E (APOE)-ε4 alleles (interaction P = .034). CONCLUSIONS: Among overweight and obese adults with type 2 diabetes mellitus, traditional risk factors did not account for the lower prevalence of cognitive impairment observed in women compared with men.
Subject(s)
Cognitive Dysfunction/epidemiology , Diabetes Mellitus, Type 2/complications , Obesity/complications , Overweight/complications , Sex Characteristics , Aged , Behavior Therapy , Cross-Sectional Studies , Female , Humans , Life Style , Male , Middle Aged , PrevalenceABSTRACT
PURPOSE OF REVIEW: There is an established association between hypertension and increased risk of poor cognitive performance and dementia including Alzheimer's disease; however, associations between antihypertensive medications (AHM) and dementia risk are less clear. An increased interest in AHM has resulted in expanding publications; however, none of the recent reviews provide comprehensive review. Our extensive review includes 24 mechanistic animal and human studies published over the last 5 years assessing relationship between AHM and cognitive function. RECENT FINDINGS: All classes of AHM showed similar result patterns in animal studies. The mechanism by which AHM exert their effect was extensively studied by evaluating well-established pathways of AD disease process, including amyloid beta (Aß), vascular, oxidative stress and inflammation pathways, but only few studies evaluated the blood pressure lowering effect on the AD disease process. Methodological limitations of the studies prevent comprehensive conclusions prior to further work evaluating AHM in animals and larger human observational studies, and selecting those with promising results for future RCTs.
Subject(s)
Antihypertensive Agents/therapeutic use , Cognitive Dysfunction/prevention & control , Cognitive Dysfunction/physiopathology , Disease Models, Animal , Hypertension/drug therapy , Hypertension/physiopathology , Alzheimer Disease/physiopathology , Alzheimer Disease/prevention & control , Amyloid beta-Peptides/physiology , Animals , Cognition/drug effects , Cognition/physiology , Humans , Risk FactorsABSTRACT
PURPOSE OF REVIEW: There is an established association between hypertension and increased risk of poor cognitive performance and dementia including Alzheimer's disease; however, associations between antihypertensive medications (AHMs) and dementia risk are less consistent. An increased interest in AHM has resulted in expanding publications; however, none of the recent reviews are comprehensive. Our extensive review includes 15 observational and randomized controlled trials (RCTs) published over the last 5 years, assessing the relationship between AHM and cognitive impairment. RECENT FINDINGS: All classes of AHM showed similar result patterns in human studies with the majority of study results reporting point estimates below one and only a small number of studies (N = 15) reporting statistically significant results in favor of a specific class. Only a small number of studies reported statistically significant results in favor of a specific class of AHM. Methodological limitations of the studies prevent definitive conclusions. Further work is now needed to evaluate the class of AHM and cognitive outcomes in future RCTs, with a particular focus on the drugs with the promising results in both animals and human observational studies.
Subject(s)
Alzheimer Disease/prevention & control , Alzheimer Disease/physiopathology , Antihypertensive Agents/therapeutic use , Cognitive Dysfunction/prevention & control , Cognitive Dysfunction/physiopathology , Hypertension/drug therapy , Hypertension/physiopathology , Humans , Observational Studies as Topic , Randomized Controlled Trials as Topic , Risk Factors , Statistics as TopicABSTRACT
OBJECTIVE: Idiopathic normal pressure hydrocephalus (iNPH) affects elderly individuals and is characterized by a progressive deterioration of gait, urinary continence, and cognition. In most cases, it is reversible with treatment. INPH is not uncommonly an unrecognized cause of dementia. We wish to raise awareness of iNPH among primary care providers who are seeing these patients first. METHODS: We reviewed the current epidemiological data regarding iNPH as well as epidemiological data regarding Alzheimer disease. We searched for the most sensitive radiological screening test for iNPH. RESULTS: Alzheimer disease comprises 60%-70% of all dementia cases, in 2023 is affecting 6.7 million Americans, about 10.7% of people 65 and older. Epidemiological data from the Scandinavian countries confirmed that 3.7% of people older than 65 have iNPH. Surgical studies confirmed the presence of early Alzheimer's pathology in about 25% of operated patients with iNPH. Useful radiological findings of iNPH include an Evans Index greater than 0.30, and a disproportionally enlarged subarachnoid space hydrocephalus (DESH). However, the callosal angle is thought to represent the best tool to discriminate iNPH from its mimics. CONCLUSIONS: According to the available epidemiological data iNPH is underdiagnosed. We strongly encourage the primary care physicians and geriatricians to ask the radiologist to measure the callosal angle on the initial brain computed tomography (or magnetic resonance) image. If the callosal angle is ≤71°, it is appropriate to refer the patient to neurosurgery for further diagnostic work-up.
Subject(s)
Alzheimer Disease , Hydrocephalus, Normal Pressure , Humans , Aged , Hydrocephalus, Normal Pressure/diagnostic imaging , Hydrocephalus, Normal Pressure/epidemiology , Hydrocephalus, Normal Pressure/surgery , Geriatricians , Cognition , Radiologists , Magnetic Resonance ImagingABSTRACT
Given the persistent challenge of differentiating idiopathic Normal Pressure Hydrocephalus (iNPH) from similar clinical entities, we conducted an in-depth proteomic study of cerebrospinal fluid (CSF) in 28 shunt-responsive iNPH patients, 38 Mild Cognitive Impairment (MCI) due to Alzheimer's disease, and 49 healthy controls. Utilizing the Olink Explore 3072 panel, we identified distinct proteomic profiles in iNPH that highlight significant downregulation of synaptic markers and cell-cell adhesion proteins. Alongside vimentin and inflammatory markers upregulation, these results suggest ependymal layer and transependymal flow dysfunction. Moreover, downregulation of multiple proteins associated with congenital hydrocephalus (e.g., L1CAM, PCDH9, ISLR2, ADAMTSL2, and B4GAT1) points to a possible shared molecular foundation between congenital hydrocephalus and iNPH. Through orthogonal partial least squares discriminant analysis (OPLS-DA), a panel comprising 13 proteins has been identified as potential diagnostic biomarkers of iNPH, pending external validation. These findings offer novel insights into the pathophysiology of iNPH, with implications for improved diagnosis.
ABSTRACT
Given the persistent challenge of differentiating idiopathic Normal Pressure Hydrocephalus (iNPH) from similar clinical entities, we conducted an in-depth proteomic study of cerebrospinal fluid (CSF) in 28 shunt-responsive iNPH patients, 38 Mild Cognitive Impairment (MCI) due to Alzheimer's disease, and 49 healthy controls. Utilizing the Olink Explore 3072 panel, we identified distinct proteomic profiles in iNPH that highlight significant downregulation of synaptic markers and cell-cell adhesion proteins. Alongside vimentin and inflammatory markers upregulation, these results suggest ependymal layer and transependymal flow dysfunction. Moreover, downregulation of multiple proteins associated with congenital hydrocephalus (e.g., L1CAM, PCDH9, ISLR2, ADAMTSL2, and B4GAT1) points to a possible shared molecular foundation between congenital hydrocephalus and iNPH. Through orthogonal partial least squares discriminant analysis (OPLS-DA), a panel comprising 13 proteins has been identified as potential diagnostic biomarkers of iNPH, pending external validation. These findings offer novel insights into the pathophysiology of iNPH, with implications for improved diagnosis.