Cache County Dementia Progression Study Research Articles

Brain‐derived neurotrophic factor genes are associated with neuropsychiatric symptom progression in dementia. The Cache county dementia progression study

AbstractBackgroundPolymorphisms in genes coding for the neurotrophin, brain‐derived neurotrophic factor (BDNF) or its receptors, have been associated with Alzheimer’s disease and related disorders (ADRD), with sex‐dependent effects. Associations with neuropsychiatric symptom (NPS) progression after dementia onset has been largely unexplored. In a population‐based cohort, we examined the relationships between BDNF gene single‐nucleotide polymorphisms (SNPs) and NPS progression after dementia onset.Method880 participants [61.3% female; mean (SD) age = 82.0 (71) years] with dementia [68.2% AD; 13.5% Vascular Dementia (VaD); 18.3% other dementia (OD)] were assessed on the Neuropsychiatric Inventory (NPI) every six‐to‐18 months. Mean(SD) baseline dementia duration was 2.9(2.7) years. The following SNPs were examined as predictors of NPI scores over time in linear mixed‐effects models: rs6265 (BDNF G196A/Val66Met), rs56164415 (BDNF C270T), rs2289656 (NTRK2 receptor TrkB), and rs2072446 (NGFR p75NTR). Covariates included age of dementia onset, education, apolipoprotein E genotype, and dementia type and duration at baseline.ResultSex‐dependent effects were found for two SNPs. Compared to those with major alleles, males with the rs56164415 minor allele exhibited a lower initial Apathy score, that increased over time (C/t*sex*time2:b = ‐0.063, SE = 0.029, p = .033); by contrast, females showed no differences by SNP alleles. Females homozygous for the rs2289656 minor allele exhibited a rapid increase in Anxiety that decreased over time (t/t*sex*time2: b = ‐0.145, SE = 0.054, p = .0073). For both sexes, presence of minor alleles for BDNF polymorphisms rs6265 (G/a*time2: b = ‐0.017, SE = 0.004, p < .001; a/a*time2: b = ‐0.035, SE = 0.013, p = .006) and rs56164415 (C/t*time2: b = 0.019, SE = 0.005, p < .001) was associated with increased NPI Agitation/Aggression well after baseline. Rs6265 minor allele homozygotes (a/a*time2: b = ‐0.049, SE = 0.013, p < .001) and rs2072446 minor allele carriers (Ct/tt*time2: b = ‐0.012, SE = 0.005, p = .025) exhibited initial increases in Delusions, which diminished approximately 5 years thereafter.ConclusionSpecific BDNF genotypes were associated with NPS presentation after dementia onset, with some sex‐dependent effects. Future research on enhancing BDNF signaling may present possible targets for intervention.

Sleep disturbance and association with cognitive and functional trajectories in all cause dementia: The Cache County Dementia Progression Study

AbstractBackgroundSleep disturbance is common in older adults, with a prevalence rate of approximately 25%. Sleep disturbance has been associated with increased risk for Alzheimer’s disease (AD), brain Aß deposition, and worse cognition in older adults in general. Few studies have examined the association between sleep disturbance and cognitive or functional decline after the onset of dementia. We examined this issue in a population‐based cohort of persons with dementia.MethodFive hundred eighty‐two participants (aged 65+, 60.3% female) with dementia from the Cache County Memory Study were followed for a mean (sd) of 2.47 (2.72) years, and maximum of 13.28 years. Mean (sd) age of dementia onset was 83.49 (6.29) years. A majority (81.3%) had a high school diploma/GED. Cognition was assessed at baseline and semi‐annual follow‐ups with the Mini‐Mental State Exam (MMSE) and functional status with the Clinical Dementia Rating sum‐of‐boxes (CDR‐sum). Sleep disturbance was based on the sleep domain from the Neuropsychiatric Inventory, or if lacking, a question about the subject being “troubled by sleep problems, insomnia.” Presence of depression was also determined from the NPI. Sleep disturbance (time varying) was examined in separate linear mixed effects models to predict changes in MMSE and CDRsum, controlling for age, gender, education, depression (yes/no) and presence of APOE E4 allele.ResultPrevalence of sleep disturbance was 29.7%. The association between sleep disturbance and cognitive and functional outcomes varied by dementia type (p interactions < .001). Compared to those with Alzheimer’s disease and sleep disturbance, individuals with vascular dementia and sleep disturbance exhibited worse (higher) CDR‐Sum scores across time (M_difference = ‐1.55, SE = .41, p < .001, d = .27) while individuals with “other dementias” and sleep disturbance performed worse on the MMSE (M_difference = 2.14, SE = .55, p < .001, d = .38) as did APOE4 carriers (M_difference = 1.45, SE = .35, p < .001, d = .26).ConclusionIndividuals with various dementia types and those with an APOE E4 allele in combination with sleep disturbance had worse cognitive and functional trajectories. Future work will examine effects of sleep medication use on dementia trajectory.

Neuropsychiatric symptoms in patients with dementia and the longitudinal costs of informal care in the Cache County population

IntroductionSeverity of dementia and neuropsychiatric symptoms contribute to increasing informal care costs. We examined which neuropsychiatric symptoms subdomains (NPS-SD) were associated with informal costs in a population-based sample. MethodsDementia progression and informal costs (2015 dollars) were estimated from the Cache County Dementia Progression Study. Overall NPS and specific NPS-SD were assessed with the Neuropsychiatric Inventory. Generalized Estimating Equations (GEE with gamma-distribution/log-link) modeled the relationship between NPS-SDs and informal cost trajectories. ResultsTwo hundred eighty participants (52.1% female; age M = 85.67, SD = 5.60) exhibited an adjusted cost increase of 5.6% (P = .005), 6.4% (P < .001), 7.6% (P = .030), and 13% (P = .024) for every increasing Neuropsychiatric Inventory unit in psychosis-SD, affective-SD, agitation/aggression-SD, and apathy-SD, respectively. An increase in each unit of apathy was associated with a 2% annual decrease in costs (P = .040). DiscussionWe extend our prior work on informal costs and dementia severity by identifying NPS-SD associated with informal costs. Interventions targeting NPS-SD may lower informal costs.

Cognitive and functional progression in Alzheimer disease: A prediction model of latent classes.

ObjectiveWe sought to replicate a previously published prediction model for progression, developed in the Cache County Dementia Progression Study, using a clinical cohort from the National Alzheimer's Coordinating Center.MethodsWe included 1120 incident Alzheimer disease (AD) cases with at least one assessment after diagnosis, originating from 31 AD centres from the United States. Trajectories of the Mini‐Mental State Examination (MMSE) and Clinical Dementia Rating sum of boxes (CDR‐sb) were modelled jointly over time using parallel‐process growth mixture models in order to identify latent classes of trajectories. Bias‐corrected multinomial logistic regression was used to identify baseline predictors of class membership and compare these with the predictors found in the Cache County Dementia Progression Study.ResultsThe best‐fitting model contained 3 classes: Class 1 was the largest (63%) and showed the slowest progression on both MMSE and CDR‐sb; classes 2 (22%) and 3 (15%) showed moderate and rapid worsening, respectively. Significant predictors of membership in classes 2 and 3, relative to class 1, were worse baseline MMSE and CDR‐sb, higher education, and lack of hypertension. Combining all previously mentioned predictors yielded areas under the receiver operating characteristic curve of 0.70 and 0.75 for classes 2 and 3, respectively, relative to class 1.ConclusionsOur replication study confirmed that it is possible to predict trajectories of progression in AD with relatively good accuracy. The class distribution was comparable with that of the original study, with most individuals being members of a class with stable or slow progression. This is important for informing newly diagnosed AD patients and their caregivers.

ANTIDEMENTIA MEDICATION USE IS ASSOCIATED WITH DECREASED INFORMAL COSTS IN MILD DEMENTIA

Antidementia medication use (ADMU) is associated with a delay in the progression of dementia symptoms, but their association with informal costs of dementia care has not been well-studied. Using the Cache County Dementia Progression Study, a population-based sample of persons with dementia (PWD), we examined daily caregiving hours for 219 PWD (46.9% female, mean (SD) age = 85.8 (5.0) years), which were estimated from the Caregiver Activity Survey. Informal costs were then calculated using the replacement cost method by multiplying hours of care by Utahan median wages in the visit year. Cost was adjusted for inflation using the Medical Consumer Price Index and expressed in 2015 dollars. ADMU was based on inspection of each participant’s medications and interview. Linear mixed models, with gamma log-link function, tested the association between antidementia medications and informal costs. Covariates included: psychotropic and anticholinergic medication use, participant’s health status, gender, and dementia severity (measured by the Clinical Dementia Rating Scale-Sum of Boxes). ADMU was 30.7% at baseline and median informal costs were $9.95/day. Overall, ADMU was not associated with informal costs (expβ = .79, p = .090) in the entire sample. In analyses restricted to participants with mild dementia severity at baseline, ADMU was associated with 28% lower costs (expβ = .72, p = .039). Among covariates, only dementia severity (time-varying) was significantly associated with informal costs. These results suggest that ADMU is associated with lower informal costs, particularly among PWD using these medications while in mild stages of dementia severity.

Closer caregiver and care-recipient relationships predict lower informal costs of dementia care: The Cache County Dementia Progression Study

IntroductionIdentifying factors associated with lower dementia care costs is essential. We examined whether two caregiver factors were associated with lower costs of informal care. MethodsA total of 271 care dyads of the Cache County Dementia Study were included. Estimates of informal costs were based on caregiver reports of time spent in care-related activities and inflation-adjusted 2012 Utah median hourly wages. Caregiver coping and emotional closeness with the care-recipient were assessed using the Ways of Coping Checklist–Revised and Relationship Closeness Scale, respectively. ResultsHigher closeness was associated with 24% lower costs (expβ = 0.763 [95% confidence interval: 0.583–0.999]) in linear mixed models controlling for demographics and baseline dementia severity and duration. Problem-focused coping was not associated with informal costs (P = .354). DiscussionCaregiver closeness, a potentially modifiable factor, predicted lower dementia informal care costs over time. Future studies examining the care environment in closer dyads may identify specific care-related behaviors or strategies that are associated with lower costs.

PC-FACS

PC-FACS

Nutritional status and severe dementia, institutionalization, and mortality: The cache county dementia progression study

Nutritional status and severe dementia, institutionalization, and mortality: The cache county dementia progression study

The association between general medical health and course of cognition, function, and neuropsychiatric symptoms in the cache county dementia progression study

A number of studies suggest a link between health status and dementia course in individuals with Alzheimer's disease (AD). We investigated the relationships between measures of health and changes in cognition, function, and neuropsychiatric symptoms in a population-baed study of incident AD. We used data from the population-based Cache County study of memory and aging (CCSMA). The sample included 335 individuals with incident AD who were followed for up to eleven years. Measures of health status at each visit included the General Medical Health Rating (GMHR), number of comorbid medical conditions, and number of non-psychiatric medications. Dementia outcomes included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating – sum of boxes (CDR-sb), and the Neuropsychiatric Inventory (NPI). Two types of longitudinal mixed effects were fit: in the first, differences in course over time on the dementia outcomes was modeled as a function of baseline health; in the second, outcomes at each timepoint were measured as a function of health at the same timepoint. All models were adjusted for sex, age, education, dementia duration at baseline, and APOE genotype. individuals demonstrated both improvements and worsening of their health status over time. Neither GMHR nor comorbidities, and non-psychiatric medications at baseline were associated with differences in rates of decline. Over time, lower GMHR ratings at a given visit were associated with worse outcomes at that same visit (MMSE: β = –1.07 p = 0.01; CDR-sb: β = 1.79 p < 0.001; NPI: β = 4.57 p = 0.01). Given that time-varying GMHR, but not baseline GMHR, was associated with each of the outcomes it seems likely that the effect is a dynamic one, but potentially modifiable. Further study, including randomized trials of dementia care models, is needed to establish the direction of causality and the efficacy of improving health as a means of ameloriating the effects of AD.

How do neuropsychiatric symptoms in persons with dementia affect caregiver physical and mental health over time? the cache county dementia progression study

How do neuropsychiatric symptoms in persons with dementia affect caregiver physical and mental health over time? the cache county dementia progression study

International Psychogeriatricspaper of the year 2014: a new tradition and the first candidate for a 2024 paper of the decade?

In 2014, the International Psychogeriatric Association (IPA) celebrated the fact that IPA's flagship scientific journalInternational Psychogeriatrics(IPG) has matured, attaining 25 years of existence since its foundation in 1989. The IPG editorial team introduced several new features in the 2014 issues to celebrate this significant quarter century milestone. One of them was the new “paper of the month” category. Following an internal selection process amongst the editorial team, who ranked available accepted papers focusing on their scientific quality and clinical relevance each month, one paper was selected as paper of the month from the categories “original research articles” and “reviews”. This resulted in 12 papers of the month, of which eight were original research articles and four were reviews or meta-analyses. Each paper of the month was accompanied by a short commentary highlighting its importance, written either by an editorial team member, one of the reviewers of the paper, or an external international expert on the topic of the paper. The editorial team aimed to highlight various psychogeriatric topics, so there are papers covering the wide spectrum of cognitive impairment, from risk factors such a hippocampal atrophy (Ferrariniet al., 2014) and traumatic brain injury (Gilbertet al., 2014), via transition between diagnostic categories on the cognitive continuum (Elliset al., 2014) to variations in symptom expression (Rockwoodet al., 2014) and apathy (Theleritiset al., 2014) to exercise interventions for people with Alzheimer's disease (AD) (Farinaet al., 2014) or antipsychotic use for patients with dementia living in residential care (Kleijeret al., 2014). Other papers reported on topics relevant to the aging process in general, such as neuroplasticity (Valkanovaet al., 2014), loneliness (Yanet al., 2014) or attitudes to aging (Shenkinet al., 2014). Other psychogeriatric topics covered were delirium (Ritchieet al., 2014) and geriatric depression (Steffenset al., 2014). In the international spirit of IPA, authors of the 12 papers come from Australia, Canada China, Greece, Germany, Italy, Mexico, the Netherlands, Switzerland, the UK, and the USA. From those 12 papers an IPG paper of the year 2014 was selected with the help of three independent reviewers: Dr Doh Kwan Kim from South Korea, Dr Gill Livingston from the UK, and Dr Daniel Weintraub from the USA. Our three reviewers ranked all 12 papers of the month independently from each other and the highest ranked paper overall was “The association of traumatic brain injury with rate of progression of cognitive and functional impairment in a population-based cohort of Alzheimer's disease: the Cache County Dementia Progression Study” by Mac Gilbert, Christine Snyder, Chris Corcoran, Maria C. Norton, Constantine G. Lyketsos, and JoAnn T. Tschanz. The reviewers emphasized that traumatic brain injury (TBI) is recognized as an important risk factor for AD which needs more research, and that the study by Gilbertet al.contributes important new knowledge to the area with the specific strength of reporting long-term follow up. In this context, we refer to the excellent commentary on the paper of the year by Dr David Sharp (Sharp, 2014), which was published alongside the paper of the year when it was paper of the month in the October 2014 issue.

Neuropsychiatric symptoms as predictors of progression to severe Alzheimer's dementia and death: the Cache County Dementia Progression Study.

Little is known about factors influencing the rate of progression of Alzheimer's dementia. Using data from the Cache County Dementia Progression Study, the authors examined the link between clinically significant neuropsychiatric symptoms in mild Alzheimer's dementia and progression to severe dementia or death. The Cache County Dementia Progression Study is a longitudinal study of dementia progression in incident cases of this condition. Survival analyses included unadjusted Kaplan-Meier plots and multivariate Cox proportional hazard models. Hazard ratio estimates controlled for age at dementia onset, dementia duration at baseline, gender, education level, General Medical Health Rating, and apolipoprotein E epsilon 4 genotype. Three hundred thirty-five patients with incident Alzheimer's dementia were studied. Sixty-eight (20%) developed severe dementia over the follow-up period. Psychosis (hazard ratio=2.007), agitation/aggression (hazard ratio=2.946), and any one clinically significant neuropsychiatric symptom (domain score ≥4, hazard ratio=2.682) were associated with more rapid progression to severe dementia. Psychosis (hazard ratio=1.537), affective symptoms (hazard ratio=1.510), agitation/aggression (hazard ratio=1.942), mildly symptomatic neuropsychiatric symptoms (domain score of 1-3, hazard ratio=1.448), and clinically significant neuropsychiatric symptoms (hazard ratio=1.951) were associated with earlier death. Specific neuropsychiatric symptoms are associated with shorter survival time from mild Alzheimer's dementia to severe dementia and/or death. The treatment of specific neuropsychiatric symptoms in mild Alzheimer's dementia should be examined for its potential to delay time to severe dementia or death.

Latent classes of course in Alzheimer's disease and predictors: the Cache County Dementia Progression Study.

Several longitudinal studies of Alzheimer's disease (AD) report heterogeneity in progression. We sought to identify groups (classes) of progression trajectories in the population-based Cache County Dementia Progression Study (N = 328) and to identify baseline predictors of membership for each group. We used parallel-process growth mixture models to identify latent classes of trajectories on the basis of Mini-Mental State Exam (MMSE) and Clinical Dementia Rating sum of boxes scores over time. We then used bias-corrected multinomial logistic regression to model baseline predictors of latent class membership. We constructed receiver operating characteristic curves to demonstrate relative predictive utility of successive sets of predictors. We fit four latent classes; class 1 was the largest (72%) and had the slowest progression. Classes 2 (8%), 3 (11%), and 4 (8%) had more rapid worsening. In univariate analyses, longer dementia duration, presence of psychosis, and worse baseline MMSE and Clinical Dementia Rating sum of boxes were associated with membership in class 2, relative to class 1. Lower education was associated with membership in class 3. In the multivariate model, only MMSE remained a statistically significant predictor of class membership. Receiver operating characteristic areas under the curve were 0.98, 0.88, and 0.67, for classes 2, 3, and 4 relative to class 1. Heterogeneity in AD course can be usefully characterized using growth mixture models. The majority belonged to a class characterized by slower decline than is typically reported in clinical samples. Class membership could be predicted using baseline covariates. Further study may advance our prediction of AD course at the population level and in turn shed light on the pathophysiology of progression.

The association of traumatic brain injury with rate of progression of cognitive and functional impairment in a population-based cohort of Alzheimer's disease: the Cache County dementia progression study by Gilbert et al. Late effects of traumatic brain injury on dementia progression.

There is compelling evidence that traumatic brain injury (TBI) can trigger neurodegeneration, and that this is a major determinant of long-term outcome (Smithet al., 2013). A single significant injury such as a road traffic accident or exposure to a bomb blast can predispose an individual to Alzheimer's disease (AD), and here Gilbert and colleagues show for the first time that a history of TBI also alters the progression the disease.

The association of traumatic brain injury with rate of progression of cognitive and functional impairment in a population-based cohort of Alzheimer's disease: the Cache County Dementia Progression Study.

There is limited research on factors that influence the rate of progression in Alzheimer's disease (AD). A history of traumatic brain injury (TBI) is associated with an increased risk for AD, but its role on the rate of dementia progression after the onset of AD has not been examined. A population-based cohort of 325 persons with incident AD was followed for up to 11 years. The sample was 65% female with a mean (SD) age of dementia onset = 84.4 (6.4) years. History of TBI was categorized as number, severity (with or without loss of consciousness), and timing in relation to dementia onset (within ten years or more than ten years). Cognition was assessed by the Consortium to Establish a Registry of AD battery, and functional ability was assessed by the Clinical Dementia Rating Sum of Boxes. In linear mixed models, a history of TBI within ten years of onset showed faster progression of functional impairment (LR x2 = 10.27, p = 0.006), while those with TBI more than ten years before dementia onset had higher scores on a measure of list learning (β = 1.61, p = 0.003) and semantic memory (β = 0.75, p = 0.0035). History of TBI and its recency may be a useful factor to predict functional progression in the course of AD.

Caregiver personality predicts rate of cognitive decline in a community sample of persons with Alzheimer's disease. The Cache County Dementia Progression Study.

Environmental influences on the rate of Alzheimer's disease (AD) progression have received little attention. Our objective was to test hypotheses concerning associations between caregiver personality traits and the rate of AD progression. Care receivers (CR) were 161 persons with AD from a population-based dementia progression study; 55 of their caregivers were spouses and 106 were adult children. Cognitive status of the CR was measured with the Mini-Mental State Examination every six months, over an average of 5.6 (range: 1-14) years. Linear mixed models tested rate of cognitive decline as a function of caregiver personality traits from the NEO Five-Factor Inventory. Significantly faster cognitive decline was observed with higher caregiver Neuroticism overall; however, in stratified models, effects were significant for adult child but not spouse caregivers. Neuroticism facets of depression, anxiety, and vulnerability to stress were significantly associated with faster decline. Higher caregiver Extraversion was associated with slower decline in the CR when caregivers were adult children but not spouses. For adult child caregivers, caregiver personality traits are associated with rate of cognitive decline in CRs with AD regardless of co-residency. Results suggest that dementia caregiver interventions promoting positive care management strategies and ways to react to caregiving challenges may eventually become an important complement to pharmacologic and other approaches aimed at slower rate of decline in dementia.

Vascular factors as predictors of severe dementia and mortality in Alzheimer's disease: The Cache County dementia progression study

Vascular factors as predictors of severe dementia and mortality in Alzheimer's disease: The Cache County dementia progression study

Variants in PPP3R1 and MAPT are associated with more rapid functional decline in Alzheimer's disease: The Cache County Dementia Progression Study

BackgroundSingle-nucleotide polymorphisms (SNPs) located in the gene encoding the regulatory subunit of the protein phosphatase 2B (PPP3R1, rs1868402) and the microtubule-associated protein tau (MAPT, rs3785883) gene were recently associated with higher cerebrospinal fluid (CSF) tau levels in samples from the Knight Alzheimer's Disease Research Center at Washington University (WU) and Alzheimer's Disease Neuroimaging Initiative (ADNI). In these same samples, these SNPs were also associated with faster functional decline, or progression of Alzheimer's disease (AD) as measured by the Clinical Dementia Rating sum of boxes scores (CDR-sb). We attempted to validate the latter association in an independent, population-based sample of incident AD cases from the Cache County Dementia Progression Study (DPS). MethodsAll 92 AD cases from the DPS with a global CDR-sb ≤1 (mild) at initial clinical assessment who were later assessed on CDR-sb data on at least two other time points were genotyped at the two SNPs of interest (rs1868402 and rs3785883). We used linear mixed models to estimate associations between these SNPs and CDR-sb trajectory. All analyses were performed using Proc Mixed in SAS. ResultsAlthough we observed no association between rs3785883 or rs1868402 alone and change in CDR-sb (P > .10), there was a significant association between a combined genotype model and change in CDR-sb: carriers of the high-risk genotypes at both loci progressed >2.9 times faster than noncarriers (P = .015). When data from DPS were combined with previously published data from WU and ADNI, change in CDR-sb was 30% faster for each copy of the high-risk allele at rs3785883 (P = .0082) and carriers of both high-risk genotypes at both loci progressed 6 times faster (P < .0001) than all others combined. ConclusionsWe replicate a previous report by Cruchaga et al that specific variations in rs3785883 and rs1868402 are associated with accelerated progression of AD. Further characterization of this association will provide a better understanding of how genetic factors influence the rate of progression of AD and could provide novel insights into preventative and therapeutic strategies.

Caregivers’ relationship closeness with the person with dementia predicts both positive and negative outcomes for caregivers’ physical health and psychological well-being

Closer relationships between caregivers and care recipients with dementia are associated with positive outcomes for care recipients, but it is unclear if closeness is a risk or protective factor for the health and psychological well-being of caregivers. We examined 234 care dyads from the population-based Cache County Dementia Progression Study. Caregivers included spouses (49%) and adult offspring (51%). Care recipients mostly had dementia of the Alzheimer's type (62%). Linear mixed models tested associations between relationship closeness at baseline or changes in closeness prior to versus after dementia onset, with baseline levels and changes over time in caregiver affect (Affect Balance Scale, ABS), depression (Beck Depression Inventory, BDI), and mental and physical health (components of the Short-Form Health Survey, SF-12). After controlling for demographic characteristics of the caregiver, number of caregiver health conditions, and characteristics of the care recipient (type of dementia, functional ability, and behavioral disturbances), we found that higher baseline closeness predicted higher baseline SF-12 mental health scores (better mental health) and lower depression. Higher baseline closeness also predicted greater worsening over time in ABS and SF-12 mental health. In addition, caregivers who reported a loss of closeness in their relationship with the care recipient from pre- to post-dementia displayed improved scores on ABS and SF-12 mental health, but worse SF-12 physical health over the course of the study. These results suggest that closeness and loss of closeness in the care dyad may be associated with both positive and adverse outcomes for caregivers, both cross-sectionally and over time.

P3‐137: Does the length of time between traumatic brain injury and the onset of Alzheimer's disease affect the rate of cognitive and functional progression?: The Cache County Dementia Progression Study

P3‐137: Does the length of time between traumatic brain injury and the onset of Alzheimer's disease affect the rate of cognitive and functional progression?: The Cache County Dementia Progression Study