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1.
Alzheimers Dement (Amst) ; 15(2): e12443, 2023.
Article in English | MEDLINE | ID: mdl-37223334

ABSTRACT

Introduction: Women with hypertensive disorders of pregnancy (HDP) have an increased risk of cardiovascular disease. Whether HDP is also associated with later-life dementia has not been fully explored. Methods: Using the Utah Population Database, we performed an 80-year retrospective cohort study of 59,668 parous women. Results: Women with, versus without, HDP, had a 1.37 higher risk of all-cause dementia (95% confidence interval [CI]: 1.26, 1.50) after adjustment for maternal age at index birth, birth year, and parity. HDP was associated with a 1.64 higher risk of vascular dementia (95% CI: 1.19, 2.26) and 1.49 higher risk of other dementia (95% CI: 1.34, 1.65) but not Alzheimer's disease dementia (adjusted hazard ratio = 1.04; 95% CI: 0.87, 1.24). Gestational hypertension and preeclampsia/eclampsia showed similar increased dementia risk. Nine mid-life cardiometabolic and mental health conditions explained 61% of HDP's effect on subsequent dementia risk. Discussion: Improved HDP and mid-life care could reduce the risk of dementia.

2.
J Nucl Med ; 64(2): 294-303, 2023 02.
Article in English | MEDLINE | ID: mdl-36137760

ABSTRACT

A standardized approach to acquiring amyloid PET images increases their value as disease and drug response biomarkers. Most 18F PET amyloid brain scans often are assessed only visually (per regulatory labels), with a binary decision indicating the presence or absence of Alzheimer disease amyloid pathology. Minimizing technical variance allows precise, quantitative SUV ratios (SUVRs) for early detection of ß-amyloid plaques and allows the effectiveness of antiamyloid treatments to be assessed with serial studies. Methods: The Quantitative Imaging Biomarkers Alliance amyloid PET biomarker committee developed and validated a profile to characterize and reduce the variability of SUVRs, increasing statistical power for these assessments. Results: On achieving conformance, sites can justify a claim that brain amyloid burden reflected by the SUVR is measurable to a within-subject coefficient of variation of no more than 1.94% when the same radiopharmaceutical, scanner, acquisition, and analysis protocols are used. Conclusion: This overview explains the claim, requirements, barriers, and potential future developments of the profile to achieve precision in clinical and research amyloid PET imaging.


Subject(s)
Alzheimer Disease , Image Processing, Computer-Assisted , Humans , Image Processing, Computer-Assisted/methods , Positron-Emission Tomography/methods , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Brain/metabolism , Biomarkers , Amyloid/metabolism , Aniline Compounds
3.
J Nucl Med ; 63(Suppl 1): 2S-12S, 2022 06.
Article in English | MEDLINE | ID: mdl-35649653

ABSTRACT

Since the invention of 18F-FDG as a neurochemical tracer in the 1970s, 18F-FDG PET has been used extensively for dementia research and clinical applications. FDG, a glucose analog, is transported into the brain via glucose transporters and metabolized in a concerted process involving astrocytes and neurons. Although the exact cellular mechanisms of glucose consumption are still under investigation, 18F-FDG PET can sensitively detect altered neuronal activity due to neurodegeneration. Various neurodegenerative disorders affect different areas of the brain, which can be depicted as altered 18F-FDG uptake by PET. The spatial patterns and severity of such changes can be reproducibly visualized by statistical mapping technology, which has become widely available in the clinic. The differentiation of 3 major neurodegenerative disorders by 18F-FDG PET, Alzheimer disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB), has become standard practice. As the nosology of FTD evolves, frontotemporal lobar degeneration, the umbrella term for pathology affecting the frontal and temporal lobes, has been subclassified clinically into behavioral variant FTD; primary progressive aphasia with 3 subtypes, semantic, nonfluent, and logopenic variants; and movement disorders including progressive supranuclear palsy and corticobasal degeneration. Each of these subtypes is associated with differential 18F-FDG PET findings. The discovery of new pathologic markers and clinicopathologic correlations via larger autopsy series have led to newly recognized or redefined disease categories, such as limbic-predominant age-related TDP-43 encephalopathy, hippocampus sclerosis, primary age-related tauopathy, and argyrophilic grain disease, which have become a focus of investigations by molecular imaging. These findings need to be integrated into the modern interpretation of 18F-FDG PET. Recent pathologic investigations also have revealed a high prevalence, particularly in the elderly, of mixed dementia with overlapping and coexisting pathologies. The interpretation of 18F-FDG PET is evolving from a traditional dichotomous diagnosis of AD versus FTD (or DLB) to a determination of the most predominant underlying pathology that would best explain the patient's symptoms, for the purpose of care guidance. 18F-FDG PET is a relatively low cost and widely available imaging modality that can help assess various neurodegenerative disorders in a single test and remains the workhorse in clinical dementia evaluation.


Subject(s)
Alzheimer Disease , Frontotemporal Dementia , Neurodegenerative Diseases , Aged , Alzheimer Disease/metabolism , Fluorodeoxyglucose F18 , Frontotemporal Dementia/diagnostic imaging , Glucose , Humans , Neurodegenerative Diseases/diagnostic imaging , Positron-Emission Tomography/methods
4.
Biol Sex Differ ; 13(1): 16, 2022 04 12.
Article in English | MEDLINE | ID: mdl-35414037

ABSTRACT

BACKGROUND: Prior research indicates that at least 35% of Alzheimer's disease and related dementia risk may be amenable to prevention. Subjective cognitive decline is often the first indication of preclinical dementia, with the risk of subsequent Alzheimer's disease in such individuals being greater in women than men. We wished to understand how modifiable factors are associated with subjective cognitive decline, and whether differences exist by sex. METHODS: Data were collected from men and women (45 years and older) who completed the U.S. Behavioral Risk Factor Surveillance System Cognitive Decline Module (2015-2018), n = 216,838. We calculated population-attributable fractions for subjective cognitive decline, stratified by sex, of the following factors: limited education, deafness, social isolation, depression, smoking, physical inactivity, obesity, hypertension, and diabetes. Our models were adjusted for age, race, income, employment, marital and Veteran status, and accounted for communality among risk factors. RESULTS: The final study sample included more women (53.7%) than men, but both had a similar prevalence of subjective cognitive decline (10.6% of women versus 11.2% of men). Women and men had nearly equivalent overall population-attributable fractions to explain subjective cognitive decline (39.7% for women versus 41.3% for men). The top three contributing risk factors were social isolation, depression, and hypertension, which explained three-quarters of the overall population-attributable fraction. CONCLUSIONS: While we did not identify any differences in modifiable factors between men and women contributing to subjective cognitive decline, other factors including reproductive or endocrinological health history or biological factors that interact with sex to modify risk warrant further research.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Hypertension , Behavioral Risk Factor Surveillance System , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/psychology , Female , Humans , Hypertension/epidemiology , Male , Risk Factors
5.
Alzheimers Dement ; 18(10): 1812-1823, 2022 10.
Article in English | MEDLINE | ID: mdl-34873816

ABSTRACT

INTRODUCTION: Retrospective studies using administrative data may be an efficient way to assess risk factors for dementia if diagnostic accuracy is known. METHODS: Within-individual clinical diagnoses of Alzheimer's disease (AD) and all-cause dementia in ambulatory (outpatient) surgery, inpatient, Medicare administrative records and death certificates were compared with research diagnoses among participants of Cache County Study on Memory, Health, and Aging (CCSMHA) (1995-2008, N = 5092). RESULTS: Combining all sources of clinical health data increased sensitivity for identifying all-cause dementia (71%) and AD (48%), while maintaining relatively high specificity (81% and 93%, respectively). Medicare claims had the highest sensitivity for case identification (57% and 40%, respectively). DISCUSSION: Administrative health data may provide a less accurate method than a research evaluation for identifying individuals with dementing disease, but accuracy is improved by combining health data sources. Assessing all-cause dementia versus a specific cause of dementia such as AD will result in increased sensitivity, but at a cost to specificity.


Subject(s)
Alzheimer Disease , Dementia , Humans , Aged , United States , Dementia/diagnosis , Retrospective Studies , Death Certificates , Medicare , Alzheimer Disease/diagnosis , Sensitivity and Specificity
6.
Laryngoscope ; 132 Suppl 7: S1-S15, 2022 04.
Article in English | MEDLINE | ID: mdl-34738240

ABSTRACT

OBJECTIVES/HYPOTHESIS: We hypothesize that treating hearing loss through cochlear implantation in older adults will improve cognitive function. STUDY DESIGN: Prospective, interventional study. METHODS: Thirty-seven participants aged 65 years and older who met criteria for cochlear implantation were enrolled. Subjects underwent preoperative cognitive testing with a novel arrangement of standard neuropsychological tests, including tests of general cognition and mood (Mini-Mental Status Exam [MMSE]), tests of verbally based stimuli and responses (Digit Span, Stroop, Hopkins Verbal Learning Test-Revised [HVLT-R], Hayling Sentence Completion), and comparable visually based tests (Spatial Span, d2 Test of Attention, Brief Visuospatial Memory Test [BVMT], Trails A and B). Testing was repeated 12 months postoperatively. RESULTS: One year postoperatively, subjects showed a statistically significant improvement in hearing and on the following tests of cognitive function: concentration performance of the d2 Test of Attention, Hayling Sentence Completion Test, HVLT-R (total and delayed recall), Spatial Span (backward), and Stroop Color Word Test. A subgroup analysis was performed comparing 13 participants with preoperative cognitive impairment (MMSE ≤ 24) to 24 participants with normal cognition (MMSE ≥ 25). In this subgroup analysis, a greater magnitude of improvement was seen in those with impaired cognition, with statistically significant improvement in Digit Span (scaled score), Stroop Word (T-score), Stroop Color-Word (residual and T-score), HVLT-R, and Hayling (overall). All verbally based test scores improved, and 75% of the visually based test scores improved. CONCLUSIONS: This study demonstrates the cognitive benefits of cochlear implantation in older adults 1 year after surgery. For older adults with cognitive impairment prior to cochlear implantation, the cognitive benefits were even greater than in subjects with normal cognition. LEVEL OF EVIDENCE: 3, nonrandomized controlled cohort Laryngoscope, 132:S1-S15, 2022.


Subject(s)
Cochlear Implantation , Hearing Loss , Aged , Cognition , Humans , Neuropsychological Tests , Prospective Studies
7.
OTO Open ; 5(3): 2473974X211044084, 2021.
Article in English | MEDLINE | ID: mdl-34595366

ABSTRACT

OBJECTIVE: To evaluate whether frailty or age increases the risk of postoperative complications following cochlear implant (CI) surgery. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary academic center. METHODS: An evaluation of all adult patients undergoing cochlear implantation between 2006 and 2020 was performed. The 5-item Modified Frailty Index (mFI-5, comprising preoperative history of pulmonary disease, heart failure, hypertension, diabetes, and partially/totally dependent functional status) was calculated for all patients included in analysis in addition to demographic characteristics. The primary outcome was postoperative complications following CI within a 3-month period. Major complications included myocardial infarction, bleeding, and cerebrospinal fluid leak, among others. Predictors of postoperative complications were examined using multivariable logistic regression reporting odds ratios (ORs) and 95% CIs. RESULTS: There were 520 patients included for review with a median age of 68 (range, 18-94) years and a slight male predominance (n = 283, 54.4%). There were 340 patients (65.4%) who were robust (nonfrail) with an mFI of 0, while 180 (34.6%) had an mFI of ≥1. There were 20 patients who experienced a postoperative complication (3.85%). There was no statistically significant association between postoperative complications as a result of preoperative frailty (OR, 1.56; 95% CI, 0.98-2.48, P = .06) or age as a continuous variable (OR, 0.99; 95% CI, 0.97-1.02, P = .51). CONCLUSIONS: CI is safe for elderly and frail patients and carries no additional risk of complications when compared to younger, healthier patients. While medical comorbidities should always be considered perioperatively, this study supports the notion that implantation is low risk in older, frail patients.

8.
Ann Otol Rhinol Laryngol ; 130(4): 343-349, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32819168

ABSTRACT

OBJECTIVES: To determine whether central speech processing ability, as measured by hearing in noise, differs between right and left ears in adults with Alzheimer's disease related dementia (AD) as well as whether differences in central speech processing ability correlate with an fMRI-based measurement of global functional brain connectivity. METHODS: This prospective study was carried out at a tertiary referral center. Patients with an AD diagnosis and pure tone averages 40 dB HL or better were included. They were examined using resting-state fMRI and underwent central audiometric testing using the Dichotic Sentence Identification Test (DSI), the Dichotic Digits Test (DD), and the Synthetic Sentence Identification Test (SS), which test hearing in noise. DSI scores were correlated with resting-state fMRI connectivity between 361 distinct gray matter brain regions of interest (ROIs). Average global connectivity was calculated as mean functional connectivity between an ROI and the other 360 regions, a quantitative marker representing overall functional connectivity in the brain. RESULTS: Sixteen subjects had adequate fMRI and hearing data. The average age was 71.5 years old (±6.0). The average DSI score for the left ear was 40% (±34%) compared to 90% (±10%) in the right ear (P < .001). No difference between ears was noted on the DD. SS does not differentiate between ears, but worsening scores were noted with increasing background noise. Of the fMRI ROIs, 269 of the 361 had multiple comparison corrected significant correlations between global connectivity and DSI of the left ear (P = .004, r = .673), and all 269 showed higher functional connectivity for individuals with higher left DSI score. No correlations between DSI of the right ear and functional connectivity were found. CONCLUSIONS: Correlation was noted between left sided DSI and functional connectivity in patients with AD. Auditory input from the left ear was more susceptible to impairment, suggesting that side-specific auditory input may influence central auditory processing.


Subject(s)
Alzheimer Disease , Auditory Pathways/physiopathology , Hearing Loss, Central , Hearing Loss, Unilateral , Magnetic Resonance Imaging/methods , Aged , Alzheimer Disease/complications , Alzheimer Disease/physiopathology , Audiometry, Pure-Tone/methods , Connectome/methods , Correlation of Data , Female , Functional Neuroimaging/methods , Hearing Loss, Central/diagnosis , Hearing Loss, Central/etiology , Hearing Loss, Central/physiopathology , Hearing Loss, Unilateral/diagnosis , Hearing Loss, Unilateral/etiology , Hearing Loss, Unilateral/physiopathology , Humans , Male , Speech Perception/physiology
9.
Otol Neurotol ; 41(10): 1327-1333, 2020 12.
Article in English | MEDLINE | ID: mdl-32810019

ABSTRACT

OBJECTIVE: To evaluate the relationship between degree of cognitive impairment and gray-matter density changes in the auditory cortex. STUDY DESIGN: Retrospective case-control. PATIENTS: Six hundred sixty-three patients of a tertiary referral center cognitive disorders clinic. INTERVENTION: Magnetic resonance imaging. MAIN OUTCOME MEASURES: Ratios of gray matter density of the primary auditory cortex (A1) to whole brain and auditory association cortex (AAC) to whole brain in patients with Alzheimer's disease (AD) compared with mild cognitive impairment (MCI) and patients with a mini-mental state exam (MMSE) scores ≤25 versus >25. RESULTS: After multivariate analysis, a statistically significant difference between AAC to brain ratios for patients with a MMSE ≤25 (n = 325) compared with >25 (n = 269) was found, with values -0.03 (95% CI -0.04 to -0.02, p < 0.0001) on the left and -0.04 (95% CI -0.06 to -0.03, p < 0.0001) on the right. The adjusted average difference of left and right AAC to brain ratios between AD patients (n = 218) compared with MCI patients (n = 121) was also statistically significant, at -0.03 (95% CI -0.05 to -0.01, p = 0.004) and -0.05 (95% CI -0.07 to -0.03, p < 0.0001), respectively. There was no statistically significant difference in the left or right A1 to brain ratios between the MMSE groups or between the AD and MCI groups. CONCLUSIONS: The AAC for patients with MMSE ≤25 and for those with AD shows decreased gray matter density when compared with patients with better cognitive function. No difference was detected in A1, raising the possibility that patients may have intact neural hearing, but impaired ability to interpret sounds.


Subject(s)
Alzheimer Disease , Cognition Disorders , Cognitive Dysfunction , Alzheimer Disease/diagnostic imaging , Brain , Cognitive Dysfunction/diagnostic imaging , Humans , Magnetic Resonance Imaging , Retrospective Studies
11.
Neurology ; 92(15): e1745-e1753, 2019 04 09.
Article in English | MEDLINE | ID: mdl-30867271

ABSTRACT

OBJECTIVE: The inherited component for Alzheimer disease (AD) risk has focused on close relatives; consideration of the full family history may improve accuracy and utility of risk estimates. METHODS: A population resource including a genealogy of Utah pioneers from the 1800s linked to Utah death certificates was used to estimate relative risk for AD based on specific family history constellations, including from first- to third-degree relatives. RESULTS: Any affected first-degree relatives (FDR) significantly increased risk of AD (≥1 FDRs: relative risk [RR] 1.73, 95% confidence interval [CI] [1.59-1.87]; ≥2 FDRs: RR 3.98 [3.26-4.82]; ≥3 FDRs: RR 2.48 [1.07-4.89]; ≥4 FDRs: RR 14.77 [5.42-32.15]). Affected second-degree relatives (SDR) increased risk even in the presence of affected FDRs (FDR = 1 with SDR = 2: RR 21.29 [5.80-54.52]). AD only in third-degree relatives (TDR) also increased risk (FDR = 0, SDR = 0, TDR ≥3: RR 1.43 [1.21-1.68]). Mixed evidence was observed for differences in risk based on maternal compared to paternal inheritance; higher risks for men than women with equivalent family history, and higher risk for individuals with at least one affected FDR regardless of the relative's age at death, were observed. CONCLUSIONS: This population-based estimation of RRs for AD based on family history ascertained from extended genealogy data indicates that inherited genetic factors have a broad influence, extending beyond immediate relatives. Providers should consider the full constellation of family history when counseling patients and families about their risk of AD.


Subject(s)
Alzheimer Disease/epidemiology , Alzheimer Disease/genetics , Adult , Age Factors , Aged , Aged, 80 and over , Family , Fathers , Female , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Mothers , Registries , Risk Assessment , Sex Factors , Utah/epidemiology
12.
Innov Aging ; 2(2): igy025, 2018 Jun.
Article in English | MEDLINE | ID: mdl-30480142

ABSTRACT

In December 2017, the National Academy of Neuropsychology convened an interorganizational Summit on Population Health Solutions for Assessing Cognitive Impairment in Geriatric Patients in Denver, Colorado. The Summit brought together representatives of a broad range of stakeholders invested in the care of older adults to focus on the topic of cognitive health and aging. Summit participants specifically examined questions of who should be screened for cognitive impairment and how they should be screened in medical settings. This is important in the context of an acute illness given that the presence of cognitive impairment can have significant implications for care and for the management of concomitant diseases as well as pose a major risk factor for dementia. Participants arrived at general principles to guide future screening approaches in medical populations and identified knowledge gaps to direct future research. Key learning points of the summit included: recognizing the importance of educating patients and healthcare providers about the value of assessing current and baseline cognition;emphasizing that any screening tool must be appropriately normalized and validated in the population in which it is used to obtain accurate information, including considerations of language, cultural factors, and education; andrecognizing the great potential, with appropriate caveats, of electronic health records to augment cognitive screening and tracking of changes in cognitive health over time.

13.
Clin Neuropsychol ; 32(7): 1193-1225, 2018.
Article in English | MEDLINE | ID: mdl-30396329

ABSTRACT

In December 2017, the National Academy of Neuropsychology convened an interorganizational Summit on Population Health Solutions for Assessing Cognitive Impairment in Geriatric Patients in Denver, Colorado. The Summit brought together representatives of a broad range of stakeholders invested in the care of older adults to focus on the topic of cognitive health and aging. Summit participants specifically examined questions of who should be screened for cognitive impairment and how they should be screened in medical settings. This is important in the context of an acute illness given that the presence of cognitive impairment can have significant implications for care and for the management of concomitant diseases as well as pose a major risk factor for dementia. Participants arrived at general principles to guide future screening approaches in medical populations and identified knowledge gaps to direct future research. Key learning points of the summit included: recognizing the importance of educating patients and healthcare providers about the value of assessing current and baseline cognition; emphasizing that any screening tool must be appropriately normalized and validated in the population in which it is used to obtain accurate information, including considerations of language, cultural factors, and education; and recognizing the great potential, with appropriate caveats, of electronic health records to augment cognitive screening and tracking of changes in cognitive health over time.


Subject(s)
Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/psychology , Neuropsychological Tests , Population Health , Aged , Aged, 80 and over , Cognitive Dysfunction/epidemiology , Colorado , Congresses as Topic/trends , Delivery of Health Care/methods , Dementia/diagnosis , Dementia/epidemiology , Dementia/psychology , Female , Humans , Male
15.
Neurodegener Dis Manag ; 7(2): 107-117, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28445082

ABSTRACT

AIM: Amyloid positron emission tomography (aPET) measurement of Alzheimer's disease (AD) pathology could improve the accurate diagnosis of cognitive disorders. Appropriate use criteria recommend that only dementia experts order aPET. MATERIALS & METHODS: We surveyed 145 dementia experts about their current approaches to evaluation and treatment and the likely influence of aPET. RESULTS: Experts expected aPET to alter diagnostic procedures and patient management and also increase diagnostic certainty. They anticipated confirming AD or altering pharmacological treatment following positive results more than excluding AD following negative results. Experts familiar with aPET reported changes that were more consistent with appropriate use criteria and published evidence. CONCLUSIONS: Knowledge about aPET strongly influenced effects on diagnostic certainty and changed clinical practice. Dementia experts may need additional training to achieve optimal benefit from aPET.


Subject(s)
Alzheimer Disease/diagnostic imaging , Positron-Emission Tomography/methods , Alzheimer Disease/therapy , Amyloid beta-Peptides , Cognition Disorders , Dementia/diagnostic imaging , Dementia/therapy , Health Care Surveys , Humans
16.
Clin Neuropsychol ; 31(3): 531-543, 2017 04.
Article in English | MEDLINE | ID: mdl-28077020

ABSTRACT

OBJECTIVE: The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has been used extensively for clinical care and in research for patients with mild cognitive impairment and Alzheimer's disease (AD); however, relatively few studies have evaluated the relationship between RBANS performance and AD imaging biomarkers. The purpose of the current study was to evaluate the association between a relatively new amyloid positron emission tomography imaging biomarker and performance on the RBANS. METHODS: Twenty-seven nondemented community-dwelling adults over the age of 65 underwent 18F-Flutemetamol amyloid- positron emission tomography imaging, along with cognitive testing using the RBANS and select behavioral measures. Partial correlation coefficients were used to identify relationships between the imaging and behavioral markers. RESULTS: After controlling for age and education, amyloid deposition and RBANS Indexes of Immediate Memory, Delayed Memory, and Total Scale score were significantly correlated (p's < .001, r's = -.73 to -.77, d's = 2.13-2.39), with greater amyloid burden being associated with lower RBANS scores. The Delayed Memory Index was particularly highly associated with 18F-Flutemetamol binding (r2 = .59, p < .001, d = 2.39). Neither 18F-Flutemetamol binding nor RBANS performance was significantly correlated with levels of depression, subjective cognitive difficulties, or premorbid intellect. CONCLUSIONS: Because of the limited use of amyloid imaging in clinical settings due to high cost and lack of reimbursement, these findings suggest that in particular RBANS Delayed Memory Index may be a cost-efficient tool to identify early signs of AD pathology, and its use may enlighten clinical decision-making regarding potential progression to dementia due to AD.


Subject(s)
Aniline Compounds/pharmacokinetics , Benzothiazoles/pharmacokinetics , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/psychology , Neuropsychological Tests , Radiopharmaceuticals/pharmacokinetics , Aged , Aged, 80 and over , Alzheimer Disease/psychology , Amyloid beta-Peptides/metabolism , Behavior , Cognition Disorders/diagnostic imaging , Cognition Disorders/psychology , Educational Status , Female , Humans , Intelligence , Male , Memory , Positron-Emission Tomography
17.
Alzheimers Dement ; 11(7): 757-71, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26194311

ABSTRACT

INTRODUCTION: This article reviews the work done in the Alzheimer's Disease Neuroimaging Initiative positron emission tomography (ADNI PET) core over the past 5 years, largely concerning techniques, methods, and results related to amyloid imaging in ADNI. METHODS: The PET Core has used [(18)F]florbetapir routinely on ADNI participants, with over 1600 scans available for download. Four different laboratories are involved in data analysis, and have examined factors such as longitudinal florbetapir analysis, use of [(18)F]fluorodeoxyglucose (FDG)-PET in clinical trials, and relationships between different biomarkers and cognition. RESULTS: Converging evidence from the PET Core has indicated that cross-sectional and longitudinal florbetapir analyses require different reference regions. Studies have also examined the relationship between florbetapir data obtained immediately after injection, which reflects perfusion, and FDG-PET results. Finally, standardization has included the translation of florbetapir PET data to a centiloid scale. CONCLUSION: The PET Core has demonstrated a variety of methods for the standardization of biomarkers such as florbetapir PET in a multicenter setting.


Subject(s)
Alzheimer Disease/diagnosis , Brain/diagnostic imaging , Positron-Emission Tomography , Alzheimer Disease/complications , Alzheimer Disease/genetics , Apolipoprotein E4/genetics , Brain Mapping , Cognition Disorders/etiology , Fluorodeoxyglucose F18/pharmacokinetics , Humans , Imaging, Three-Dimensional , Longitudinal Studies
18.
Arch Clin Neuropsychol ; 30(3): 264-70, 2015 May.
Article in English | MEDLINE | ID: mdl-25908614

ABSTRACT

Practice effects are improvements in cognitive test scores due to repeated exposure to the same tests. Typically viewed as error, short-term practice effects have been shown to provide valuable clinical information about diagnosis, prognosis, and treatment outcomes in older patients with mild cognitive impairments. This study examined short-term practice effects across one week and brain hypometabolism on fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in 25 older adults (15 intact, 10 Mild Cognitive Impairment). Averaged cerebral brain metabolism on FDG PET was correlated with multiple cognitive scores at baseline in those with Mild Cognitive Impairment, and short-term practice effects accounted for additional variance in these same subjects. The relationship between brain metabolism and cognition (either at baseline or practice effects) was minimal in the intact individuals. Although needing replication in larger samples, short-term practice effects on tests of executive functioning and memory may provide valuable information about biomarkers of Alzheimer's disease.


Subject(s)
Brain/metabolism , Cognitive Dysfunction/metabolism , Practice, Psychological , Aged , Brain/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Executive Function , Female , Humans , Male , Memory , Middle Aged , Neuropsychological Tests , Radionuclide Imaging
19.
JAMA Neurol ; 72(5): 571-81, 2015 May.
Article in English | MEDLINE | ID: mdl-25822737

ABSTRACT

IMPORTANCE: Cerebrospinal fluid (CSF) and positron emission tomographic (PET) amyloid biomarkers have been proposed for the detection of Alzheimer disease (AD) pathology in living patients and for the tracking of longitudinal changes, but the relation between biomarkers needs further study. OBJECTIVE: To determine the association between CSF and PET amyloid biomarkers (cross-sectional and longitudinal measures) and compare the cutoffs for these measures. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal clinical cohort study from 2005 to 2014 including 820 participants with at least 1 florbetapir F-18 (hereafter referred to as simply florbetapir)-PET scan and at least 1 CSF ß-amyloid 1-42 (Aß1-42) sample obtained within 30 days of each other (501 participants had a second PET scan after 2 years, including 150 participants with CSF Aß1-42 measurements). Data were obtained from the Alzheimer's Disease Neuroimaging Initiative database. MAIN OUTCOMES AND MEASURES: Four different PET scans processing pipelines from 2 different laboratories were compared. The PET cutoff values were established using a mixture-modeling approach, and different mathematical models were applied to define the association between CSF and PET amyloid measures. RESULTS: The values of the CSF Aß1-42 samples and florbetapir-PET scans showed a nonlinear association (R2 = 0.48-0.66), with the strongest association for values in the middle range. The presence of a larger dynamic range of florbetapir-PET scan values in the higher range compared with the CSF Aß1-42 plateau explained the differences in correlation with cognition (R2 = 0.36 and R2 = 0.25, respectively). The APOE genotype significantly modified the association between both biomarkers. The PET cutoff values derived from an unsupervised classifier converged with previous PET cutoff values and the established CSF Aß1-42 cutoff levels. There was no association between longitudinal Aß1-42 levels and standardized uptake value ratios during follow-up. CONCLUSIONS AND RELEVANCE: The association between both biomarkers is limited to a middle range of values, is modified by the APOE genotype, and is absent for longitudinal changes; 4 different approaches in 2 different platforms converge on similar pathological Aß cutoff levels; and different pipelines to process PET scans showed correlated but not identical results. Our findings suggest that both biomarkers measure different aspects of AD Aß pathology.


Subject(s)
Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Biomarkers , Aged , Aged, 80 and over , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/diagnostic imaging , Amyloid beta-Peptides/cerebrospinal fluid , Aniline Compounds , Cross-Sectional Studies , Ethylene Glycols , Female , Humans , Longitudinal Studies , Male , Peptide Fragments/cerebrospinal fluid , Positron-Emission Tomography
20.
J Genet Couns ; 24(3): 503-11, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25641253

ABSTRACT

Cognitively impaired patients with dementia often rely on health advocates or guardians, such as spouses or adult offspring, to consent for medical procedures. These family members may also decide whether an autopsy is performed after death or whether their family member donates tissues. However, spouses are not genetically related to the patient and may have different perspectives than genetically related family members when making medical decisions with genetic implications, such as participation in a tissue repository (biobank). Interviews were conducted with spouses and adult offspring of individuals with a progressive dementing disease. Both spouses and offspring were supportive of the patient with dementia to participate in tissue storage. The top perceived benefits of tissue storage in both offspring and spouses were future value for family members and advancement of medical knowledge. Concerns included misuse of the tissue and insurance discrimination. Although the personal genetic implications differ between spouses and offspring, they share similar attitudes about the importance of tissue banking for the individual with a dementing disease.


Subject(s)
Adult Children/psychology , Dementia , Spouses/psychology , Tissue Banks , Attitude , Female , Humans , Male , Perception
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