Intervention for Cognitive Reserve Enhancement in Delaying the Onset of Alzheimer's Symptomatic Expression (INCREASE) Study: Results from a Randomized Controlled Study of Medication Therapy Management Targeting a Delay in Prodromal Dementia Symptom Progression.

BACKGROUND: Cognitive reserve has been hypothesized as a mechanism to explain differences in individual risk for symptomatic expression of Alzheimer's Disease (AD). Inappropriate medications may diminish cognitive reserve, precipitating the transition from preclinical AD (pAD) to a symptomatic state. To date, there is limited data on the potential impact of medication optimization as a potential tool for slowing the symptomatic expression of AD. OBJECTIVES: (1) To test the efficacy of a medication therapy management intervention designed to bolster cognitive reserve in community-dwelling older adults without dementia. (2) To evaluate the efficacy of intervention by baseline pAD status. DESIGN: A 1-year randomized controlled trial was conducted in community-dwelling older adults without dementia. Randomization was stratified by amyloid ß positron emission tomography levels. SETTING: Community-based, Lexington, Kentucky. PARTICIPANTS: Adults 65 years or older with no evidence of dementia and reporting at least one potentially inappropriate medication as listed in the Beers 2015 criteria were recruited. The study aimed to enroll 90 participants based on the a priori sample size calculation. INTERVENTION: Medication therapy management versus standard of care. MEASUREMENTS: Primary outcomes were: (1) one-year changes in the Medication Appropriateness Index; (2) one-year changes in Trail Making Test B under scopolamine challenge. RESULTS: The medication therapy management intervention resulted in significant improvement in Medication Appropriateness Index scores. Overall, there was no beneficial effect of the medication therapy management on Trail Making Test B scores, however stratified analysis demonstrated improvement in Trail Making Test B challenged scores associated with the medication therapy management for those with elevated amyloid ß positron emission tomography levels consistent with pAD. CONCLUSIONS: Medication therapy management can reduce inappropriate medication use in older adults at risk for AD. Our study indicated beneficial cognitive effects in those with preclinical Alzheimer's Disease. No statistically significant effects were evident in the study group as a whole, or in those without preclinical cerebral amyloidosis. Further work designed to improve the effectiveness of the medication therapy management approach and defining other preclinical pathologic states that may benefit from medication optimization are readily achievable goals for promoting improved cognitive health and potentially delaying the onset of symptomatic AD.

Mental Component Score (MCS) from Health-Related Quality of Life Predicts Incidence of Dementia in U.S. Males.

BACKGROUND: The Medical Outcomes Study Questionnaire Short Form 36 health survey (SF-36) measures health-related quality of life (HRQoL) from the individual's point of view and is an indicator of overall health status. OBJECTIVE: To examine whether HRQoL shows differential changes over time prior to dementia onset and investigate whether HRQoL predicts incidence of dementia. DESIGN: Prevention of Alzheimer's Disease (AD) by Vitamin E and Selenium (PREADViSE) trial, which recruited 7,547 non-demented men between 2002 and 2009. A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis. SETTING: Secondary data analysis of PREADViSE data. PARTICIPANTS: A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis. MEASUREMENTS: Two summary T scores were generated for analysis: physical component score (PCS) and mental component score (MCS), each with a mean of 50 (standard deviation of 10); higher scores are better. Linear mixed models (LMM) were applied to determine if mean component scores varied over time or by eventual dementia status. Cox proportional hazards regression was used to determine if the baseline component scores were associated with dementia incidence, adjusting for baseline age, race, APOE-4 carrier status, sleep apnea, and self-reported memory complaint at baseline. RESULTS: The mean baseline MCS score for participants who later developed dementia (mean± SD: 53.9±9.5) was significantly lower than for those participants who did not develop dementia during the study (mean±SD: 56.4±6.5; p = 0.005). Mean PCS scores at baseline (dementia: 49.3±7.9 vs. non-dementia: 49.8±7.8) were not significantly different (p = 0.5) but LMM analysis showed a significant time effect. For MCS, the indicator for eventual dementia diagnosis was significantly associated with poorer scores after adjusting for baseline age, race, and memory complaint. Adjusted for other baseline risk factors, the Cox model showed that a 10-unit increase in MCS was associated with a 44% decrease in the hazard of a future dementia diagnosis (95% CI: 32%-55%). CONCLUSION: The SF-36 MCS summary score may serve as a predictor for future dementia and could be prognostic in longitudinal dementia research.

Review: Relationship of type 2 diabetes to human brain pathology.

Type 2 diabetes (T2D) and Alzheimer's disease (AD) are both highly prevalent diseases worldwide, and each is associated with high-morbidity and high-mortality. Numerous clinical studies have consistently shown that T2D confers a two-fold increased risk for a dementia, including dementia attributable to AD. Yet, the mechanisms underlying this relationship, especially nonvascular mechanisms, remain debated. Cerebral vascular disease (CVD) is likely to be playing a role. But increased AD neuropathologic changes (ADNC), specifically neuritic amyloid plaques (AP) and neurofibrillary tangles (NFT), are also posited mechanisms. The clinicopathological studies to date demonstrate T2D to be consistently associated with infarcts, particularly subcortical lacunar infarcts, but not ADNC, suggesting the association of T2D with dementia may largely be mediated through CVD. Furthermore, growing interest exists in insulin resistance (IR), particularly IR within the brain itself, which may be an associated but distinct phenomenon from T2D, and possibly itself associated with ADNC. Other mechanisms largely related to protein processing and efflux in the central nervous system with altered function in T2D may also be involved. Such mechanisms include islet amyloid polypeptide (or amylin) deposition, co-localized with beta-amyloid and found in more abundance in the AD temporal cortex, blood-brain barrier breakdown and dysfunction, potentially related to pericyte degeneration, and disturbance of brain lymphatics, both in the glial lymphatic system and the newly discovered discrete central nervous system lymph vessels. Medical research is ongoing to further disentangle the relationship of T2D to dementia in the ageing human brain.

Diabetes mitigates the role of memory complaint in predicting dementia risk: Results from the Prevention of Alzheimer's Disease with Vitamin E and Selenium Study.

BACKGROUND: Subjective memory complaints (SMCs) are associated with increased risk of dementia in older adults, but the role of comorbidities in modifying this risk is unknown. OBJECTIVES: To assess whether comorbidities modify estimated dementia risk based on SMCs. DESIGN: The Prevention of Alzheimer's Disease with Vitamin E and Selenium Study (PREADVISE) was designed as an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT), a randomized, multi-center prostate cancer prevention trial with sites in the Unites States, Puerto Rico, and Canada. In 2009, PREADVISE and SELECT were changed into cohort studies. SETTING: Secondary analysis of PREADVISE data. PARTICIPANTS: PREADVISE recruited 7,540 non-demented male volunteers from participating SELECT sites from 2002 to 2009. SMCs, demographics, and comorbidities including hypertension, diabetes, coronary artery bypass graft (CABG), stroke, sleep apnea, and head injury were ascertained by participant interview. MEASUREMENTS: Cox models were used to investigate whether baseline comorbidities modified hazard ratios (HR) for SMC-associated dementia risk using two methods: (1) we included one interaction term between SMC and a comorbidity in the model at a time, and (2) we included all two-way interactions between SMC and covariates of interest and reduced the model by "backward" selection. SMC was operationalized as any complaint vs. no complaint. RESULTS: Baseline SMCs were common (23.6%). In the first analyses, with the exception of stroke, presence of self-reported comorbidities was associated with lower estimated HR for dementia based on SMC status (complaint vs. no complaint), but this difference was only significant for diabetes. In the second analysis, the two-way interactions between SMC and race as well as SMC and diabetes were significant. Here, black men without diabetes who reported SMC had the highest estimated dementia risk (HR=5.05, 95% CI 2.55-10.00), while non-black men with diabetes who reported SMC had the lowest estimated risk (HR=0.71, 95% CI 0.35-1.41). CONCLUSIONS: SMCs were more common among men with comorbidities, but these complaints appeared to be less predictive of dementia risk than those originating from men without comorbidities, suggesting that medical conditions such as diabetes may explain SMCs that are unrelated to an underlying neurodegenerative process.

The Effect of Vascular Neuropathology on Late-life Cognition: Results from the SMART Project.

BACKGROUND: Cerebral vascular pathology may contribute to cognitive decline experienced by some elderly near death. Given evidence for mixed neuropathologies in advanced age, preventing or reducing cerebrovascular burden in late life may be beneficial. OBJECTIVE: To correlate measures of cerebral vascular pathology with cognitive trajectories. SETTING: Observational study. PARTICIPANTS: A cohort of 2,274 individuals who came to autopsy at a mean age of 89.3 years and 82 percent of whom had at least two cognitive assessments within the last six years of life was compiled from six centers conducting longitudinal studies. MEASUREMENTS: For each cognitive domain: immediate and delayed memory, language, and naming, three trajectories were examined: good, intermediate, and poor cognition. The probability of a participant belonging to each trajectory was associated with measures of cerebral vascular pathology after adjustment for demographics, APOE, and Alzheimer neuropathology. RESULTS: A large proportion of the cohort (72-94%) experienced good or intermediate cognition in the four domains examined. The presence of arteriolosclerosis and the presence of lacunar infarcts doubled the odds of belonging to the poor cognitive trajectory for language when compared to the good trajectory. The presence of lacunar infarcts increased the odds of an intermediate or poor trajectory for immediate and delayed recall while the presence of large artery infarcts increased the odds of poor trajectories for all four cognitive domains examined. Microinfarcts and cerebral amyloid angiopathy had little effect on the trajectories. CONCLUSION: Indicators of cerebral vascular pathology act differently on late life cognition.

(1)H-MRS metabolites in adults with Down syndrome: Effects of dementia.

To determine if proton magnetic resonance spectroscopy ((1)H-MRS) detect differences in dementia status in adults with Down syndrome (DS), we used (1)H-MRS to measure neuronal and glial metabolites in the posterior cingulate cortex in 22 adults with DS and in 15 age- and gender-matched healthy controls. We evaluated associations between (1)H-MRS results and cognition among DS participants. Neuronal biomarkers, including N-acetylaspartate (NAA) and glutamate-glutamine complex (Glx), were significantly lower in DS patients with Alzheimer's should probably be changed to Alzheimer (without ' or s) through ms as per the new naming standard disease (DSAD) when compared to non-demented DS (DS) and healthy controls (CTL). Neuronal biomarkers therefore appear to reflect dementia status in DS. In contrast, all DS participants had significantly higher myo-inositol (MI), a putative glial biomarker, compared to CTL. Our data indicate that there may be an overall higher glial inflammatory component in DS compared to CTL prior to and possibly independent of developing dementia. When computing the NAA to MI ratio, we found that presence or absence of dementia could be distinguished in DS. NAA, Glx, and NAA/MI in all DS participants were correlated with scores from the Brief Praxis Test and the Severe Impairment Battery. (1)H-MRS may be a useful diagnostic tool in future longitudinal studies to measure AD progression in persons with DS. In particular, NAA and the NAA/MI ratio is sensitive to the functional status of adults with DS, including prior to dementia.

Factors Associated with Unmet Needs among African-American Dementia Care Providers.

Racial and ethnic minorities currently comprise 20% of the U.S. population; in 2050, this figure is expected to rise to 42%. As a result, Alzheimer's disease (AD), the 5th leading cause of death for people aged 65 and older, is likely to increase in these groups. Most dementia caregiving for these populations comes from family and friends, especially among families with lower socioeconomic status. A convenience sample of 30 African-American dementia caregivers was interviewed to determine unmet needs. Participants expressed a limited desire for formal services, such as support groups, legal advice, case management, and homemaker services. Instead, commonly expressed needs were daytime respite care and especially a desire for family and social support. Many caregivers expressed a need for other family members to share responsibility in the process; therefore, methods for caregiver support that address multiple family members in care provision may be beneficial for this group.

Self-Reported Memory Complaints: A Comparison of Demented and Unimpaired Outcomes.

BACKGROUND: Subjective memory complaints are common in aged persons, indicating an increased, but incompletely understood, risk for dementia. OBJECTIVE: To compare cognitive trajectories and autopsy results of individuals with subjective complaints after stratifying by whether a subsequent clinical dementia occurred. DESIGN: Observational study. SETTING: University of Kentucky cohort with yearly longitudinal assessments and eventual autopsies. PARTICIPANTS: Among 516 patients who were cognitively intact and depression-free at enrollment, 296 declared a memory complaint during follow-up. Among those who came to autopsy, 118 died but never developed dementia, while 36 died following dementia diagnosis. MEASUREMENTS: Cognitive domain trajectories were compared using linear mixed models adjusted for age, gender, years of education and APOE status. Neuropathological findings were compared cross-sectionally after adjustment for age at death. RESULTS: While the groups had comparable cognitive test scores at enrollment and the time of the first declaration of a complaint, the group with subsequent dementia development had steeper slopes of decline in episodic memory and naming but not fluency or sequencing. Autopsies showed the dementia group had more severe Alzheimer pathology and a higher proportion of subjects with hippocampal sclerosis of aging and arteriolosclerosis, whereas the non-demented group had a higher proportion expressing primary age related tauopathy (PART). CONCLUSIONS: While memory complaints are common among the elderly, not all individuals progress to dementia. This study indicates that biomarkers are needed to predict whether a complaint will lead to dementia if this is used as enrollment criteria in future clinical trials.

Baseline subjective memory complaints associate with increased risk of incident dementia: the PREADVISE trial.

BACKGROUND: Subjective memory complaints reflect patient-identified deficits in memory and have been linked to increased risk of future dementia in nondemented (including cognitively intact) older adults. OBJECTIVES: To assess the risk of incident dementia during follow-up for participants in the Prevention of Alzheimer's Disease with Vitamin E and Selenium (PREADVISE) study who reported memory complaints at baseline. DESIGN: Double-blind, placebo controlled 2×2 randomized controlled trial that transformed into an observational cohort following discontinuation of supplementation in the SELECT parent trial. SETTING: PREADVISE participants were assessed at 130 local clinical study sites in the United States, Canada, and Puerto Rico during the controlled trial phase and were later followed by telephone from a centralized location during the observational phase. PARTICIPANTS: PREADVISE enrolled a total of 7,547 nondemented men over the age of 60; 4,271 consented to participation in the observational study. MEASUREMENTS: Participants were interviewed at baseline for memory complaints. The Memory Impairment Screen (MIS) was administered to each participant at the annual memory screening. Participants who failed the MIS also received a more detailed neurocognitive assessment: an expanded Consortium to Establish a Registry in Alzheimer's Disease (CERADe) neuropsychological battery was used during the RCT, and the modified Telephone Interview for Cognitive Status (TICS-m) was used during the observational study. Participants who failed the second screen were asked to have a memory work-up with a local physician and to share their medical records with PREADVISE. Subgroups of men who did not fail the MIS were also asked to complete the CERADe battery and TICS-m for validation purposes. Additional measures collected include self-reported medical history, medication use, and the AD8 Dementia Screening Test. RESULTS: After controlling for important risk factors for dementia, Cox proportional hazards regression revealed that men who reported memory changes at baseline had an 80% increase in the hazard of incident dementia compared to men who reported no SMC. Men who reported memory problems at baseline had almost a 6-fold increase in the hazard of incident dementia compared to men who reported no memory complaint. CONCLUSIONS: Memory complaints in nondemented older men predicted future dementia. Men who reported that the changes in their memory were a problem were especially at risk, and the presence of common comorbidities like diabetes, sleep apnea, and history of head injury further exacerbated this risk.

The Statistical Modeling of Aging and Risk of Transition Project: Data Collection and Harmonization Across 11 Longitudinal Cohort Studies of Aging, Cognition, and Dementia.

Longitudinal cognitive trajectories and other factors associated with mixed neuropathologies (such as Alzheimer's disease with co-occurring cerebrovascular disease) remain incompletely understood, despite being the rule and not the exception in older populations. The Statistical Modeling of Aging and Risk of Transition study (SMART) is a consortium of 11 different high-quality longitudinal studies of aging and cognition (N=11,541 participants) established for the purpose of characterizing risk and protective factors associated with subtypes of age-associated mixed neuropathologies (N=3,001 autopsies). While brain donation was not required for participation in all SMART cohorts, most achieved substantial autopsy rates (i.e., > 50%). Moreover, the studies comprising SMART have large numbers of participants who were followed from intact cognition and transitioned to cognitive impairment and dementia, as well as participants who remained cognitively intact until death. These data provide an exciting opportunity to apply sophisticated statistical methods, like Markov processes, that require large, well-characterized samples. Thus, SMART will serve as an important resource for the field of mixed dementia epidemiology and neuropathology.

A randomized controlled Alzheimer's disease prevention trial's evolution into an exposure trial: the PREADViSE Trial.

OBJECTIVES: To summarize the ongoing prevention of Alzheimer's disease (AD) by vitamin E and selenium (PREADViSE) trial as an ancillary study to SELECT (a large prostate cancer prevention trial) and to present the blinded results of the first year as an exposure study. DESIGN: PREADViSE was designed as a double blind randomized controlled trial (RCT). SETTING: SELECT terminated after median of 5.5 years of exposure to supplements due to a futility analysis. Both trials then converted into an exposure study. PARTICIPANTS: In the randomized component PREADViSE enrolled 7,547 men age 62 or older (60 if African American). Once the trial terminated 4,246 of these men volunteered for the exposure study. Demographics were similar for both groups with exposure volunteers having baseline mean age 67.3 ± 5.2 years, 15.3 ± 2.4 years of education, 9.8% African Americans, and 22.0% reporting a family history of dementia. INTERVENTION: In the RCT men were randomly assigned to either daily doses of 400 IU of vitamin E or placebo and 200 µg of selenium or placebo using a 2x2 factorial structure. MEASUREMENTS: In the RCT, participants completed the memory impairment screen (MIS), and if they failed, underwent a longer screening (based on an expanded Consortium to Establish a Registry in AD [CERAD] battery). CERAD failure resulted in visits to their clinician for medical examination with records of these examinations forwarded to the PREADViSE center for further review. In the exposure study, men are contacted by telephone and complete the telephone version of the memory impairment screen (MIS-T) screen. If they fail the MIS-T, a modified telephone interview of cognitive status (TICS-M) exam is given. A failed TICS-M exam also leads to a visit to their clinician for an in-depth examination and forwarding of records for a centralized consensus diagnosis by expert clinicians. A subgroup of the men who pass the MIS-T also take the TICS-M exam for validation purposes. RESULTS: While this ancillary trial was open to all 427 SELECT clinical sites, only 130 (30.0%) of the sites chose to participate in PREADViSE. Staff turnover at the sites presented challenges when training persons unfamiliar with cognitive testing procedures to conduct the memory screens. In the RCT few participants (1.6%) failed the MIS screen and among those who passed this screen a significant practice effect was encountered. In the exposure study 3,581 men were reached by phone in year 1, 15.7% could not be reached after 5 calls, and of those contacted 6.0% refused the screen even after consenting to the procedures at their clinical site. Most notable is that the failure rate for the MIS-T increased fourfold to 7.2%. Of the 257 men who took the TICS-M, 84.0% failed and were asked to contact their physicians for a more detailed memory assessment, and approximately half of these had some form of dementia or cognitive impairment. Several of these dementia cases are not AD. CONCLUSION: Partnering with SELECT led to an AD prevention trial conducted at a very reasonable cost by taking advantage of the experience and efficient clinical trial management found in a cancer cooperative group (Southwest Oncology Group or SWOG). Once unblinded, the RCT and exposure study data have the potential to yield new information on long term exposure to antioxidant supplements under controlled conditions.

Differential reports of pain and depression differentiate mild cognitive impairment from cognitively intact elderly participants.

BACKGROUND: Positive associations between pain and depression in the general population have been well characterized; however, the interplay between pain, depression, and early cognitive decline, characterized as mild cognitive impairment (MCI), is poorly understood. METHODS: The current study examined the association of self-reported pain complaints (measured by the 36-item Short Form Health Survey) and self-reported depressive symptoms (measured by the 30-item Geriatric Depression Scale) in cognitively intact participants (n = 492) and participants with a clinical diagnosis of MCI (n = 83). RESULTS: Depressive symptoms and subjective reports of pain were significantly associated in the entire sample (r = .29; P < .0001). Multiple logistic regression modeling (adjusted for age, education, and APOE4 status as covariates) demonstrated that while depressive symptoms were positively associated with the diagnosis of MCI (P < .001), subjective pain reports were negatively associated with MCI (P < .002). CONCLUSION: While the negative association of subjective pain complaints with MCI might arguably be explained by the development of anosognosia, self-reports of depressive symptoms were actually increased in these participants, suggesting preserved insight into cognitive decline-associated symptoms. It is possible that preferential involvement of limbic circuitry in MCI could explain these findings. Future studies are needed to elucidate the reasons for the dissociation of pain and depressive symptoms in MCI described in the present article.

Attention-deficit/hyperactivity disorder in childhood is associated with cognitive test profiles in the geriatric population but not with mild cognitive impairment or Alzheimer's disease.

The frequency of ADHD in the aging population and its relationship to late-life cognitive decline has not been studied previously. To address this gap in our understanding, the Wender-Utah ADHD Rating scale (WURS) was administered to 310 geriatric subjects with cognitive status ranging from normal cognition to mild cognitive impairment to overt dementia. The frequency of WURS-positive ADHD in this sample was 4.4%. WURS scores were not related to cognitive diagnoses, but did show nonlinear associations with tasks requiring sustained attention. The frequency of ADHD appears stable across generations and does not appear to be associated with MCI or dementia diagnoses. The association of attentional processing deficits and WURS scores in geriatric subjects could suggest that such traits remain stable throughout life. Caution should be considered when interpreting cognitive test profiles in the aging population that exhibit signs and symptoms of ADHD, as attentional deficits may not necessarily imply the existence of an underlying neurodegenerative disease state.

Prodromal clinical manifestations of neuropathologically confirmed Lewy body disease.

The mild cognitive impairment (MCI) stage of dementia with Lewy bodies (MCI-DLB) has not yet been defined, but is likely to differ in the MCI stage of Alzheimer's disease (MCI-AD). To determine whether clinical features distinguish MCI-DLB and MCI-AD, 9 cases of neuropathologically confirmed MCI-DLB and 12 cases of MCI-AD were compared. No significant differences were found between MCI-DLB and MCI-AD cases in age at death, gender, ApoE status, education, time followed while clinically normal, or duration of MCI. MCI-DLB and MCI-AD cases differed clinically in the expression of Parkinsonism (P=0.012), provoked hallucinations or delirium (P=0.042), or the presence of any of these noncognitive symptoms of DLB (P<0.0001). Letter fluency (P=0.007) was significantly lower and Wechsler Logical Memory I (P=0.019) was significantly higher in MCI-DLB compared to MCI-AD cases. These data demonstrate the feasibility of differentiating underlying pathologic processes responsible for cognitive decline in the preclinical disease state and suggest that further refinement in diagnostic criteria may allow more accurate early detection of prodromal DLB and AD.

Relative preservation of MMSE scores in autopsy-proven dementia with Lewy bodies.

BACKGROUND: Recent studies raised questions about the severity of cognitive impairment associated with dementia with Lewy bodies (DLB). However, there have been few analyses of large, multicenter data registries for clinical-pathologic correlation. METHODS: We evaluated data from the National Alzheimer's Coordinating Center registry (n = 5,813 cases meeting initial inclusion criteria) and the University of Kentucky Alzheimer's Disease Center autopsy series (n = 527) to compare quantitatively the severity of cognitive impairment associated with DLB pathology vs Alzheimer disease (AD) and AD+DLB pathologies. RESULTS: Mini-Mental State Examination (MMSE) scores showed that persons with pure DLB had cognitive impairment of relatively moderate severity (final MMSE score 15.6 +/- 8.7) compared to patients with pure AD and AD+DLB (final MMSE score 10.7 +/- 8.6 and 10.6 +/- 8.6). Persons with pure DLB pathology from both data sets had more years of formal education and were more likely to be male. Differences in final MMSE scores were significant (p < 0.01) between pure DLB and both AD+DLB and pure AD even after correction for education level, gender, and MMSE-death interval. Even in cases with extensive neocortical LBs, the degree of cognitive impairment was most strongly related to the amount of concomitant AD-type neurofibrillary pathology. CONCLUSIONS: Dementia with Lewy bodies can constitute a debilitating disease with associated psychiatric, motoric, and autonomic dysfunction. However, neocortical Lewy bodies are not a substrate for severe global cognitive impairment as assessed by the Mini-Mental State Examination. Instead, neocortical Lewy bodies appear to constitute or reflect an additive disease process, requiring Alzheimer disease or other concomitant brain diseases to induce severe global cognitive deterioration.

Clinical features of mild cognitive impairment differ in the research and tertiary clinic settings.

OBJECTIVE: Comparative analysis of subjects with mild cognitive impairment (MCI) diagnosed in a primary research setting and those seen in a tertiary care memory disorders clinic. METHODS: Subjects who received a diagnosis of MCI between July 1, 2005, and December 31, 2006, in a longitudinal research study of normal cognition (n = 48) and patients diagnosed in a tertiary care referral clinic (n = 34) were evaluated using similar methodologies. Comparative analyses of detailed medical, neurological and neuropsychological data are presented. RESULTS: The diagnosis of MCI was not accepted by 13 of 48 subjects (27%) classified as MCI in the primary research setting. Nondegenerative, potentially treatable causes of cognitive decline were found in 3 of 34 subjects (9%) seen in the tertiary referral clinic and in 11 of 35 subjects (31%) identified as MCI in the primary research setting (p = 0.02, Fisher's exact test). MCI subjects identified in the primary research setting were older than those referred to the memory clinic (mean +/- SD, 79.7 +/- 7.0 vs. 71.5 +/- 9.0 years, p < 0.0001, t test) and had more years of education (16.0 +/- 3.2 vs. 13.6 +/- 4.2 years, p < 0.01, t test). MCI subjects in the primary research setting appeared to be in a milder stage of disease, characterized by higher Mini-Mental State Examination scores (28.2 +/- 1.8 vs. 25.7 +/- 1.8, p < 0.0001), and a tendency towards single domain involvement, predominantly memory (mean number of domains involved, 1.0 vs. 2.5, p < 0.0001). More advanced stages of MCI, seen in the tertiary referral population, had additional involvement of attention (p < 0.0001, Fisher's exact test) and visuospatial domains (p < 0.0002, Fisher's exact test). Semiquantitative grading of hippocampal and medial temporal lobe atrophy did not differ between groups (p = 0.81, Mann-Whitney U test). CONCLUSIONS: The diagnosis of MCI may be unwelcome in naïve persons. Remedial causes of MCI should be actively investigated. Demographic and clinical characteristics of MCI differ between research subjects and patients referred to a tertiary care clinic.