Stricker Learning Span criterion validity: a remote self-administered multi-device compatible digital word list memory measure shows similar ability to differentiate amyloid and tau PET-defined biomarker groups as in-person Auditory Verbal Learning Test.

OBJECTIVE: The Stricker Learning Span (SLS) is a computer-adaptive digital word list memory test specifically designed for remote assessment and self-administration on a web-based multi-device platform (Mayo Test Drive). We aimed to establish criterion validity of the SLS by comparing its ability to differentiate biomarker-defined groups to the person-administered Rey's Auditory Verbal Learning Test (AVLT). METHOD: Participants (N = 353; mean age = 71, SD = 11; 93% cognitively unimpaired [CU]) completed the AVLT during an in-person visit, the SLS remotely (within 3 months) and had brain amyloid and tau PET scans available (within 3 years). Overlapping groups were formed for 1) those on the Alzheimer's disease (AD) continuum (amyloid PET positive, A+, n = 125) or not (A-, n = 228), and those with biological AD (amyloid and tau PET positive, A+T+, n = 55) vs no evidence of AD pathology (A-T-, n = 195). Analyses were repeated among CU participants only. RESULTS: The SLS and AVLT showed similar ability to differentiate biomarker-defined groups when comparing AUROCs (p's > .05). In logistic regression models, SLS contributed significantly to predicting biomarker group beyond age, education, and sex, including when limited to CU participants. Medium (A- vs A+) to large (A-T- vs A+T+) unadjusted effect sizes were observed for both SLS and AVLT. Learning and delay variables were similar in terms of ability to separate biomarker groups. CONCLUSIONS: Remotely administered SLS performed similarly to in-person-administered AVLT in its ability to separate biomarker-defined groups, providing evidence of criterion validity. Results suggest the SLS may be sensitive to detecting subtle objective cognitive decline in preclinical AD.

Mayo normative studies: regression-based normative data for ages 30-91 years with a focus on the Boston Naming Test, Trail Making Test and Category Fluency.

OBJECTIVE: Normative neuropsychological data are essential for interpretation of test performance in the context of demographic factors. The Mayo Normative Studies (MNS) aim to provide updated normative data for neuropsychological measures administered in the Mayo Clinic Study of Aging (MCSA), a population-based study of aging that randomly samples residents of Olmsted County, Minnesota, from age- and sex-stratified groups. We examined demographic effects on neuropsychological measures and validated the regression-based norms in comparison to existing normative data developed in a similar sample. METHOD: The MNS includes cognitively unimpaired adults ≥30 years of age (n = 4,428) participating in the MCSA. Multivariable linear regressions were used to determine demographic effects on test performance. Regression-based normative formulas were developed by first converting raw scores to normalized scaled scores and then regressing on age, age2, sex, and education. Total and sex-stratified base rates of low scores (T < 40) were examined in an older adult validation sample and compared with Mayo's Older Americans Normative Studies (MOANS) norms. RESULTS: Independent linear regressions revealed variable patterns of linear and/or quadratic effects of age (r2 = 6-27% variance explained), sex (0-13%), and education (2-10%) across measures. MNS norms improved base rates of low performance in the older adult validation sample overall and in sex-specific patterns relative to MOANS. CONCLUSIONS: Our results demonstrate the need for updated norms that consider complex demographic associations on test performance and that specifically exclude participants with mild cognitive impairment from the normative sample.

Mayo normative studies: A conditional normative model for longitudinal change on the Auditory Verbal Learning Test and preliminary validation in preclinical Alzheimer's disease.

Introduction: The aim of this study was to develop a conditional normative model for Rey's Auditory Verbal Learning Test (AVLT) that accounts for practice effects. Methods: In our normative sample, robust conditional norms were derived from 1001 cognitively unimpaired (CU) adults ages 50 to 89 who completed the AVLT up to eight times. Linear mixed-effects models adjusted for baseline performance, prior test exposures, time, demographics, and interaction terms. In our preliminary validation, mean performance on conditional and typical normative scores across two to four completed follow-up tests in preclinical Alzheimer's disease participants at baseline with positive amyloid and tau positron emission (n = 27 CU amyloid [A]+tau[T]+) was compared to biomarker negative individuals (n = 269 CU A-T-). Results: AVLT performance using typical norms did not differ across A+T+ and A-T- groups. Conditional norms z-scores were lower in the A+T+ relative to the A-T- group for 30-minute recall (P = .033) and sum of trials (P = .030). Discussion: Conditional normative methods that account for practice effects show promise for identifying longitudinal cognitive decline.

A longitudinal investigation of Aß, anxiety, depression, and mild cognitive impairment.

INTRODUCTION: We investigated the longitudinal relationship between cortical amyloid deposition, anxiety, and depression and the risk of incident mild cognitive impairment (MCI). METHODS: We followed 1440 community-dwelling, cognitively unimpaired individuals aged ≥ 50 years for a median of 5.5 years. Clinical anxiety and depression were assessed using Beck Anxiety and Depression Inventories (BAI, BDI-II). Cortical amyloid beta (Aß) was measured by Pittsburgh compound B positron emission tomography (PiB-PET) and elevated deposition (PiB+) was defined as standardized uptake value ratio ≥ 1.48. We calculated Cox proportional hazards models with age as the time scale, adjusted for sex, education, and medical comorbidity. RESULTS: Cortical Aß deposition (PiB+) independent of anxiety (BAI ≥ 10) or depression (BDI-II ≥ 13) increased the risk of MCI. There was a significant additive interaction between PiB+ and anxiety (joint effect hazard ratio 6.77; 95% confidence interval 3.58-12.79; P = .031) that is, being PiB+ and having anxiety further amplified the risk of MCI. DISCUSSION: Anxiety modified the association between PiB+ and incident MCI.

Neuropsychiatric symptoms and the outcome of cognitive trajectories in older adults free of dementia: The Mayo Clinic Study of Aging.

OBJECTIVE: Neuropsychiatric symptoms (NPS) are associated with the risk of incident mild cognitive impairment (MCI) and dementia. We examined associations between NPS and the outcomes of global and domain-specific cognitive trajectories. METHODS: In this longitudinal study conducted in the setting of the population-based Mayo Clinic Study of Aging, 5081 community-dwelling, nondemented individuals aged ≥50 years (51% males) underwent NPS assessment using Neuropsychiatric Inventory Questionnaire (NPI-Q), and Beck Depression and Anxiety Inventories (BDI-II, BAI). Global and domain-specific (memory, language, attention, and visuospatial skills) cognitive performance was assessed through neuropsychological testing every 15 months. Associations between baseline NPS and trajectories for individual yearly change in cognitive z-scores were calculated using linear mixed-effect models. RESULTS: Cognition declined regardless of NPS status over the median follow-up of 4.5 years. Presence of NPS was associated with increased cognitive decline. Differences in annualized change in global cognition z-scores for participants with NPS compared to without NPS ranged from -0.018 (95% CI -0.032, -0.004; p = 0.011) for irritability to -0.159 (-0.254, -0.065; p = 0.001) for hallucinations. Associations between NPS and annual decline in global cognition were significant for most NPI-Q-assessed NPS and clinical depression (BDI-II≥13). Participants with NPI-Q-assessed depression, apathy, nighttime behavior, and clinical depression had greater decline in all domain-specific z-scores; presence of delusions and anxiety was associated with more pronounced decline in language, attention and visuospatial skills. CONCLUSION: NPS were associated with a more accelerated cognitive decline. Clinical assessment and potential treatment of NPS is warranted even in a community setting as NPS may impact cognitive decline in nondemented individuals.

Brain Regional Glucose Metabolism, Neuropsychiatric Symptoms, and the Risk of Incident Mild Cognitive Impairment: The Mayo Clinic Study of Aging.

OBJECTIVE: The authors conducted a prospective cohort study to examine the risk of incident mild cognitive impairment (MCI) as predicted by baseline neuropsychiatric symptoms (NPS) and brain regional glucose metabolic dysfunction. METHODS: About 1,363 cognitively unimpaired individuals (52.8% males) aged ≥50 years were followed for a median of 4.8 years to the outcome of incident MCI. NPS were assessed using Beck Depression and Anxiety Inventories and Neuropsychiatric Inventory Questionnaire. Glucose hypometabolism was measured by fluorodeoxyglucose positron emission tomography and defined as standardized uptake value ratio ≤ 1.47 in regions typically affected in Alzheimer disease. Cox proportional hazards models were adjusted for age, sex, education, and APOE ε4 status. RESULTS: Participants with regional glucose hypometabolism and depression (Beck Depression Inventory-II ≥13) had a more than threefold increased risk of incident MCI (hazard ratio [95% confidence interval], 3.66 [1.75, 7.65], p <0.001, χ2 = 11.83, degree of freedom [df] = 1) as compared to the reference group (normal regional glucose metabolism and no depression), and the risk was also significantly elevated (7.21 [3.54, 14.7], p <0.001, χ2 = 29.68, df = 1) for participants with glucose hypometabolism and anxiety (Beck Anxiety Inventory ≥10). Having glucose hypometabolism and ≥1 NPS (3.74 [2.40, 5.82], p <0.001, χ2 = 34.13, df = 1) or ≥2 NPS (3.89 [2.20, 6.86], p <0.001, χ2 = 21.92, df = 1) increased the risk of incident MCI by more than three times, and having ≥3 NPS increased the risk by more than four times (4.12 [2.03, 8.37], p <0.001, χ2 = 15.39, df = 1). CONCLUSION: Combined presence of NPS with regional glucose hypometabolism is associated with an increased risk of incident MCI, with fluorodeoxyglucose positron emission tomography appearing to be a stronger driving force of cognitive decline than NPS.

Mayo Normative Studies: Regression-Based Normative Data for the Auditory Verbal Learning Test for Ages 30-91 Years and the Importance of Adjusting for Sex.

OBJECTIVE: Rey's Auditory Verbal Learning Test (AVLT) is a widely used word list memory test. We update normative data to include adjustment for verbal memory performance differences between men and women and illustrate the effect of this sex adjustment and the importance of excluding participants with mild cognitive impairment (MCI) from normative samples. METHOD: This study advances the Mayo's Older Americans Normative Studies (MOANS) by using a new population-based sample through the Mayo Clinic Study of Aging, which randomly samples residents of Olmsted County, Minnesota, from age- and sex-stratified groups. Regression-based normative T-score formulas were derived from 4428 cognitively unimpaired adults aged 30-91 years. Fully adjusted T-scores correct for age, sex, and education. We also derived T-scores that correct for (1) age or (2) age and sex. Test-retest reliability data are provided. RESULTS: From raw score analyses, sex explained a significant amount of variance in performance above and beyond age (8-10%). Applying original age-adjusted MOANS norms to the current sample resulted in significantly fewer-than-expected participants with low delayed recall performance, particularly in women. After application of new T-scores adjusted only for age, even in normative data derived from this sample, these age-adjusted T-scores showed scores <40 T occurred more frequently among men and less frequently among women relative to T-scores that also adjusted for sex. CONCLUSIONS: Our findings highlight the importance of using normative data that adjust for sex with measures of verbal memory and provide new normative data that allow for this adjustment for the AVLT.

Association Between Neuropsychiatric Symptoms and Functional Change in Older Non-Demented Adults: Mayo Clinic Study of Aging.

We examined the associations between baseline neuropsychiatric symptoms (NPS) and longitudinal changes in functional performance among 5,394 non-demented individuals aged ≥50 years (2,729 males; median age 74.2 years; 4,716 cognitively unimpaired, 678 mild cognitive impairment). After adjusting for age, sex, education, and medical comorbidities, NPS assessed by the Neuropsychiatric Inventory Questionnaire, clinical depression (Beck Depression Inventory score ≥13) and anxiety (Beck Anxiety Inventory score ≥10) were significantly associated with an increase in the Functional Activities Questionnaire score, indicating functional decline over time. This association may vary depending on the degree of cognitive impairment at baseline.

Long-term remission, relapses and maintenance therapy in adult primary central nervous system vasculitis: A single-center 35-year experience.

OBJECTIVES: To evaluate long-term treatment and outcomes of patients with primary central nervous system vasculitis (PCNSV). METHODS: In this cohort of 191 consecutive patients with PCNSV seen at Mayo Clinic, Rochester, MN, over 35 years with long-term follow-up we analyzed response to and duration of therapy, frequency of relapses, long-term remission, efficacy of maintenance therapy and initial intravenous glucocorticoid (GC) pulses, survival and degree of disability. We also compared the efficacy of initial IV and oral cyclophosphamide (CYC). RESULTS: A favorable initial response was observed in 83% of patients treated with prednisone (PDN) alone, 81% of those treated with PDN and CYC and 95% of those initially treated with PDN and an immunosuppressant other than CYC. One or more relapses were observed in 30% of patients, 35% had discontinued therapy by last follow-up, and 21.5% maintained remission for at least 12 months after discontinuing therapy. Maintenance therapy was prescribed in 19% of all patients and 34% of patients initially treated with CYC and PDN. High disability scores (Rankin 4-6) and deaths were less frequently observed in patients receiving maintenance therapy and more frequently in patients with Aß-related angiitis. Large vessel involvement and cerebral infarction at diagnosis were associated with a poor treatment response. Aspirin use was positively associated with long-term remission and having gadolinium-enhanced cerebral lesions or meninges was negatively associated. A high disability score at last follow-up and higher mortality rate were associated with increasing age, cerebral infarction and cognitive dysfunction at diagnosis. Lymphocytic vasculitis on biopsy was associated with a more benign course with reduced disability and mortality. Patients initially treated with mycophenolate mofetil had better outcomes compared to those treated with CYC and PDN. No therapeutic advantages were observed in the patients initially treated with intravenous GC pulses. Intravenous and oral CYC were equally effective in inducing the remission. CONCLUSIONS: The majority of patients with PCNSV responded to treatment. We found patient subsets with different outcomes. Mycophenolate mofetil may be an effective alternative to CYC.

Cortical ß-amyloid burden, neuropsychiatric symptoms, and cognitive status: the Mayo Clinic Study of Aging.

Neuropsychiatric symptoms (NPS) are a risk factor for cognitive impairment and are associated with cortical ß-amyloid (Aß) deposition. We conducted a cross-sectional study derived from the ongoing population-based Mayo Clinic Study of Aging to examine the frequency of NPS among cognitively unimpaired (CU) and mild cognitive impairment (MCI) participants who either have normal (A-) or abnormal (A+) Aß deposition. We also investigated whether combined presence of MCI and amyloid positivity (MCI/A+) is associated with greater odds of having NPS as compared to CU/A- (defined as reference group). Participants were 1627 CU and MCI individuals aged ≥ 50 years (54% males; median age 73 years). All participants underwent NPS assessment (Neuropsychiatric Inventory Questionnaire (NPI-Q); Beck Depression Inventory II (BDI-II); Beck Anxiety Inventory (BAI)) and 11C-PiB-PET. Participants with an SUVR > 1.42 were classified as A+. We conducted multivariable logistic regression analyses adjusted for age, sex, education, and APOE ε4 genotype status. The sample included 997 CU/A-, 446 CU/A+, 78 MCI/A-, and 106 MCI/A+ persons. For most NPS, the highest frequency of NPS was found in MCI/A+ and the lowest in CU/A-. The odds ratios of having NPS, depression (BDI ≥ 13), or anxiety (BAI ≥ 8, ≥ 10) were consistently highest for MCI/A+ participants. In conclusion, MCI with Aß burden of the brain is associated with an increased risk of having NPS as compared to MCI without Aß burden. This implies that the underlying Alzheimer's disease biology (i.e., cerebral Aß amyloidosis) may drive both cognitive and psychiatric symptoms.

Rituximab therapy for primary central nervous system vasculitis: A 6 patient experience and review of the literature.

OBJECTIVES: To assess the efficacy and safety of Rituximab (RTX) in adult primary central nervous system vasculitis (PCNSV). METHODS: We retrospectively assessed the effect of RTX in 6 patients with PCNSV. Five of the 6 were refractory to high dose glucocorticoids (GCs) and/or conventional immunosuppressants (IS). The sixth was newly diagnosed and received RTX in combination with GCs. Clinical evaluation, laboratory tests, and imaging modalities were performed at initial RTX administration and during the follow-up. Treatment response was assessed using the treating physician's global opinion regarding response and the degree of disability using the modified Rankin scale (mRS). We also performed a literature review for previous use of RTX in PCNSV using PubMed, Ovid Medline, and the Cochrane library. RESULTS: The six patients (3 females) had a median age at diagnosis of 50.5 years (range 17-68 years). All had active disease when RTX was started. In 4 patients, RTX administration was associated with a marked reduction in the number of flares (from 18 before starting RTX to 3 after). One patient, after an initial improvement, had 2 flares when B cells were depleted and he was not able to reduce prednisone below 20 mg/day. A 6th patient had a flare when B cells recovered and retreatment with RTX re-induced and maintained remission. The median mRS score at last visit (median: 2; range 0-4) was lower than that prior to treatment (median 3; range 1-5). The median prednisone daily dose before RTX administration was significantly higher than that at last follow-up (p = .006). In the literature review, we identified 5 papers describing 7 patients treated with RTX. Six patients responded to RTX with clinical and MRI improvement with no reported flares after RTX treatment. CONCLUSIONS: Our data support a potential role for RTX treatment in selected patients with PCNSV.

Primary central nervous system vasculitis mimicking brain tumor: Comprehensive analysis of 13 cases from a single institutional cohort of 191 cases.

OBJECTIVE: To describe the clinical, laboratory, and imaging features and course of patients with primary central nervous system vasculitis (PCNSV) presenting with an intracranial tumor-like mass (TLM). METHODS: We retrospectively studied a cohort of 191 consecutive patients with PCNSV seen at the Mayo Clinic, Rochester, MN over a 35-year period (1982-2017). 13/191 patients presented with a TLM. We compared the findings in these 13 patients with those from the 178 without this presentation. RESULTS: In 13 of 191 (6.8%) patients with TLM the diagnosis of PCNSV was established by cerebral biopsy. Granulomatous vasculitis was found in 11/13 patients, accompanied by vascular deposits of ß-amyloid peptide in 7. Compared to the 178 patients without TLM, the patients with TLM were more likely to be male (p = 0.04), and less likely to have a transient ischemic attack (p = 0.023), bilateral cerebral infarcts (p = 0.018), or vasculitic lesions on angiography (p = 0.045). They were more likely to have seizures (p = 0.022), gadolinium-enhanced lesions (p = 0.007), and amyloid angiopathy (p = 0.046). All 13 patients responded to therapy and 8/13 (61.5%) had a Rankin disability score of 0 at last visit. Overall, high disability scores (Rankin scores 4-6) at last follow-up were associated with increasing age (odds ratio, OR, 1.49) and cerebral infarction (OR, 3.47), but were less likely in patients with gadolinium-enhanced lesions (OR, 0.36) and amyloid angiopathy (OR, 0.21). CONCLUSION: In PCNSV a TLM at presentation represents a definable subgroup of patients with a favourable treatment response.

Leisure-Time Physical Activity and the Risk of Incident Dementia: The Mayo Clinic Study of Aging.

We conducted a prospective cohort study derived from the population-based Mayo Clinic Study of Aging. We investigated if leisure-time physical activity among individuals with mild cognitive impairment (MCI) was associated with a decreased risk of developing dementia. 280 persons aged≥70 years (median 81 years, 165 males) with MCI and available data from neurologic evaluation, neuropsychological testing, and questionnaire-based physical activity assessment, were followed for a median of 3 years to the outcomes of incident dementia or censoring variables. We conducted Cox proportional hazards regression analyses with age as a time scale and adjusted for sex, education, medical comorbidity, depression, and APOE ɛ4 status. Moderate intensity midlife physical activity among MCI participants was significantly associated with a decreased risk of incident dementia (HR = 0.64; 95% CI, 0.41-0.98). There was a non-significant trend for a decreased risk of dementia for light and vigorous intensity midlife physical activity, as well as light and moderate intensity late-life physical activity. In conclusion, we observed that physical activity may be associated with a reduced risk of dementia among individuals with MCI. Furthermore, intensity and timing of physical activity may be important factors when investigating this association.

Primary central nervous system vasculitis associated with lymphoma.

OBJECTIVES: To record the clinical findings, response to therapy, and course of patients with primary CNS vasculitis (PCNSV) associated with lymphoma. PATIENTS AND METHODS: We reviewed the histories of 936 patients with a diagnosis of any type of vasculitis and lymphoma who were seen at the Mayo Clinic over a 32-year period. Ten patients with both PCNSV and lymphoma were identified. We compared the findings in these 10 patients with those from 158 patients with PCNSV without lymphoma seen over 29 years. RESULTS: Ten of a total of 168 (5.9%) patients with PCNSV also had a history of lymphoma: 6 with Hodgkin lymphoma (HL) and 4 with non-HL (NHL). A granulomatous vasculitis was found in all 8 patients with cerebral biopsies, accompanied by vascular deposits of ß-amyloid peptide in 2. In 7 patients, medical diagnostic workup for PCNSV revealed the lymphoma. Compared to the 158 patients with PCNSV without lymphoma, patients with lymphoma were more frequently male (p = 0.04), had increased gadolinium leptomeningeal enhancement (p = 0.03) at presentation, and had more neurologic disability at last follow-up (p = 0.01). No significant differences in treatment response were observed in the 2 groups (p = 0.202). Considering all 168 patients, increased disability at last follow-up was associated with increasing age at diagnosis (odds ratio [OR] 1.4), lymphoma (OR 5.9), and cerebral infarction (OR 3.2), while reduced disability was associated with gadolinium-enhanced lesions (OR 0.43) and amyloid angiopathy (OR O.23). CONCLUSIONS: Lymphoma may be diagnosed simultaneously with PCNSV, suggesting an immunologic paraneoplastic mechanism.

Depressive and anxiety symptoms and cortical amyloid deposition among cognitively normal elderly persons: the Mayo Clinic Study of Aging.

BACKGROUND: Little is known about the association of cortical Aß with depression and anxiety among cognitively normal (CN) elderly persons. METHODS: We conducted a cross-sectional study derived from the population-based Mayo Clinic Study of Aging in Olmsted County, Minnesota; involving CN persons aged ≥ 60 years that underwent PiB-PET scans and completed Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI). Cognitive diagnosis was made by an expert consensus panel. Participants were classified as having abnormal (≥1.4; PiB+) or normal PiB-PET (<1.4; PiB-) using a global cortical to cerebellar ratio. Multi-variable logistic regression analyses were performed to calculate odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for age and sex. RESULTS: Of 1,038 CN participants (53.1% males), 379 were PiB+. Each one point symptom increase in the BDI (OR = 1.03; 1.00-1.06) and BAI (OR = 1.04; 1.01-1.08) was associated with increased odds of PiB-PET+. The number of participants with BDI > 13 (clinical depression) was greater in the PiB-PET+ than PiB-PET- group but the difference was not significant (OR = 1.42; 0.83-2.43). Similarly, the number of participants with BAI > 10 (clinical anxiety) was greater in the PiB-PET+ than PiB-PET- group but the difference was not significant (OR = 1.77; 0.97-3.22). CONCLUSIONS: As expected, depression and anxiety levels were low in this community-dwelling sample, which likely reduced our statistical power. However, we observed an informative albeit weak association between increased BDI and BAI scores and elevated cortical amyloid deposition. This observation needs to be tested in a longitudinal cohort study.

Phenoconversion from probable rapid eye movement sleep behavior disorder to mild cognitive impairment to dementia in a population-based sample.

INTRODUCTION: Rapid eye movement sleep behavior disorder (RBD) is strongly associated with synucleinopathies. In 2012, we reported an increased risk of mild cognitive impairment (MCI) and Parkinson disease (PD) in cognitively normal Olmsted County, Minnesota, residents, aged 70 to 89 years with probable RBD. Here, we examine their progression to dementia and other neurodegenerative phenotypes. METHODS: Fifteen participants with RBD who were diagnosed with either MCI or PD were longitudinally followed, and their subsequent clinical courses were reviewed. RESULTS: Over 6.4 ± 2.9 years, six of the 14 participants with MCI developed additional neurodegenerative signs, five of whom had Lewy body disease features. Four of them progressed to dementia at a mean age 84.8 ± 4.9 years, three of whom met the criteria for probable dementia with Lewy bodies. One subject with PD developed MCI, but not dementia. DISCUSSION: Our findings from the population-based sample of Olmsted County, Minnesota, residents suggest that a substantial number of RBD patients tend to develop overt synucleinopathy features over time, and RBD patients who develop MCI and subsequent dementia have clinical features most consistent with dementia with Lewy bodies.

Neuroimaging biomarkers and impaired olfaction in cognitively normal individuals.

OBJECTIVE: There is a need for inexpensive noninvasive tests to identify older healthy persons at risk for Alzheimer disease (AD) for enrollment in AD prevention trials. Our objective was to examine whether abnormalities in neuroimaging measures of amyloid and neurodegeneration are correlated with odor identification (OI) in the population-based Mayo Clinic Study of Aging. METHODS: Cognitively normal (CN) participants had olfactory function assessed using the Brief Smell Identification Test (B-SIT), underwent magnetic resonance imaging (n = 829) to assess a composite AD signature cortical thickness and hippocampal volume (HVa), and underwent 11 C-Pittsburgh compound B (n = 306) and 18 fluorodeoxyglucose (n = 305) positron emission tomography scanning to assess amyloid accumulation and brain hypometabolism, respectively. The association of neuroimaging biomarkers with OI was examined using multinomial logistic regression and simple linear regression models adjusted for potential confounders. RESULTS: Among 829 CN participants (mean age = 79.2 years; 51.5% men), 248 (29.9%) were normosmic and 78 (9.4%) had anosmia (B-SIT score < 6). Abnormal AD signature cortical thickness and reduced HVa were associated with decreased OI as a continuous measure (slope = -0.43, 95% confidence interval [CI] = -0.76 to -0.09, p = 0.01 and slope = -0.72, 95% CI = -1.15 to -0.28, p < 0.01, respectively). Reduced HVa, decreased AD signature cortical thickness, and increased amyloid accumulation were significantly associated with increased odds of anosmia. INTERPRETATION: Our findings suggest that OI may be a noninvasive, inexpensive marker for risk stratification, for identifying participants at the preclinical stage of AD who may be at risk for cognitive impairment and eligible for inclusion in AD prevention clinical trials. These cross-sectional findings remain to be validated prospectively. Ann Neurol 2017;81:871-882.

Association Between Mentally Stimulating Activities in Late Life and the Outcome of Incident Mild Cognitive Impairment, With an Analysis of the APOE ε4 Genotype.

Importance: Cross-sectional associations between engagement in mentally stimulating activities and decreased odds of having mild cognitive impairment (MCI) or Alzheimer disease have been reported. However, little is known about the longitudinal outcome of incident MCI as predicted by late-life (aged ≥70 years) mentally stimulating activities. Objectives: To test the hypothesis of an association between mentally stimulating activities in late life and the risk of incident MCI and to evaluate the influence of the apolipoprotein E (APOE) ε4 genotype. Design, Setting, and Participants: This investigation was a prospective, population-based cohort study of participants in the Mayo Clinic Study of Aging in Olmsted County, Minnesota. Participants 70 years or older who were cognitively normal at baseline were followed up to the outcome of incident MCI. The study dates were April 2006 to June 2016. Main Outcomes and Measures: At baseline, participants provided information about mentally stimulating activities within 1 year before enrollment into the study. Neurocognitive assessment was conducted at baseline, with evaluations at 15-month intervals. Cognitive diagnosis was made by an expert consensus panel based on published criteria. Hazard ratios (HRs) and 95% CIs were calculated using Cox proportional hazards regression models after adjusting for sex, age, and educational level. Results: The final cohort consisted of 1929 cognitively normal persons (median age at baseline, 77 years [interquartile range, 74-82 years]; 50.4% [n = 973] female) who were followed up to the outcome of incident MCI. During a median follow-up period of 4.0 years, it was observed that playing games (HR, 0.78; 95% CI, 0.65-0.95) and engaging in craft activities (HR, 0.72; 95% CI, 0.57-0.90), computer use (HR, 0.70; 95% CI, 0.57-0.85), and social activities (HR, 0.77; 95% CI, 0.63-0.94) were associated with a decreased risk of incident MCI. In a stratified analysis by APOE ε4 carrier status, the data point toward the lowest risk of incident MCI for APOE ɛ4 noncarriers who engage in mentally stimulating activities (eg, computer use: HR, 0.73; 95% CI, 0.58-0.92) and toward the highest risk of incident MCI for APOE ɛ4 carriers who do not engage in mentally stimulating activities (eg, no computer use: HR, 1.74; 95% CI, 1.33-2.27). Conclusions and Relevance: Cognitively normal elderly individuals who engage in specific mentally stimulating activities even in late life have a decreased risk of incident MCI. The associations may vary by APOE ε4 carrier status.

Timing of Physical Activity, Apolipoprotein E ε4 Genotype, and Risk of Incident Mild Cognitive Impairment.

OBJECTIVES: To investigate the timing (mid- vs late life) of physical activity, apolipoprotein (APO)E ε4, and risk of incident mild cognitive impairment (MCI). DESIGN: Prospective cohort study. SETTING: Mayo Clinic Study of Aging (Olmsted County, MN). PARTICIPANTS: Cognitively normal elderly adults (N = 1,830, median age 78, 50.2% female). MEASUREMENTS: Light, moderate, and vigorous physical activities in mid- and late life were assessed using a validated questionnaire. An expert consensus panel measured MCI based on published criteria. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) with age as a time scale after adjusting for sex, education, medical comorbidity, and depression. RESULTS: Light (HR = 0.58, 95% CI = 0.43-0.79) and vigorous (HR = 0.78, 95% CI = 0.63-0.97) physical activity in midlife were associated with lower risk of incident MCI. The association between moderate activity and incident MCI was not significant (HR = 0.85, 95% CI = 0.67-1.09). In late life, light (HR = 0.75, 95% CI = 0.58-0.97) and moderate (HR = 0.81, 95% CI = 0.66-0.99) but not vigorous physical activity were associated with lower risk of incident MCI. A synergistic interaction was also observed between mid- and late-life activity in reducing risk of incident MCI. Furthermore, APOE ε4 carriers who did not exercise had a higher risk of incident MCI than noncarriers who reported physical activity. CONCLUSION: Physical activity reduced the risk of incident MCI. Exercising in mid- and late life had an additive synergistic interaction in reducing the risk of MCI.