Tracy Zitzelberger

Intelligent Systems for Assessing Aging Changes: Home-Based, Unobtrusive, and Continuous Assessment of Aging

OBJECTIVES To describe a longitudinal community cohort study, Intelligent Systems for Assessing Aging Changes, that has deployed an unobtrusive home-based assessment platform in many seniors homes in the existing community. METHODS Several types of sensors have been installed in the homes of 265 elderly persons for an average of 33 months. Metrics assessed by the sensors include total daily activity, time out of home, and walking speed. Participants were given a computer as well as training, and computer usage was monitored. Participants are assessed annually with health and function questionnaires, physical examinations, and neuropsychological testing. RESULTS Mean age was 83.3 years, mean years of education was 15.5, and 73% of cohort were women. During a 4-week snapshot, participants left their home twice a day on average for a total of 208 min per day. Mean in-home walking speed was 61.0 cm/s. Participants spent 43% of days on the computer averaging 76 min per day. DISCUSSION These results demonstrate for the first time the feasibility of engaging seniors in a large-scale deployment of in-home activity assessment technology and the successful collection of these activity metrics. We plan to use this platform to determine if continuous unobtrusive monitoring may detect incident cognitive decline.

A randomized placebo-controlled trial of Ginkgo biloba for the prevention of cognitive decline

Objective: To assess the feasibility, safety, and efficacy of Ginkgo biloba extract (GBE) on delaying the progression to cognitive impairment in normal elderly aged 85 and older. Methods: Randomized, placebo-controlled, double-blind, 42-month pilot study with 118 cognitively intact subjects randomized to standardized GBE or placebo. Kaplan-Meier estimation, Cox proportional hazard, and random-effects models were used to compare the risk of progression from Clinical Dementia Rating (CDR) = 0 to CDR = 0.5 and decline in episodic memory function between GBE and placebo groups. Results: In the intention-to-treat analysis, there was no reduced risk of progression to CDR = 0.5 (log-rank test, p = 0.06) among the GBE group. There was no less of a decline in memory function among the GBE group (p = 0.05). In the secondary analysis, where we controlled the medication adherence level, the GBE group had a lower risk of progression from CDR = 0 to CDR = 0.5 (HR = 0.33, p = 0.02), and a smaller decline in memory scores (p = 0.04). There were more ischemic strokes and TIAs in the GBE group (p = 0.01). Conclusions: In unadjusted analyses, Ginkgo biloba extract (GBE) neither altered the risk of progression from normal to Clinical Dementia Rating (CDR) = 0.5, nor protected against a decline in memory function. Secondary analysis taking into account medication adherence showed a protective effect of GBE on the progression to CDR = 0.5 and memory decline. Results of larger prevention trials taking into account medication adherence may clarify the effectiveness of GBE. More stroke and TIA cases observed among the GBE group requires further study to confirm.

Unobtrusive assessment of activity patterns associated with mild cognitive impairment

Timely detection of early cognitive impairment is difficult. Measures taken in the clinic reflect a single snapshot of performance that might be confounded by the increased variability typical in aging and disease. We evaluated the use of continuous, long‐term, and unobtrusive in‐home monitoring to assess neurologic function in healthy and cognitively impaired elders.

Serial position effects in mild cognitive impairment

Mild cognitive impairment (MCI) is often associated with the preclinical phase of Alzheimers disease (AD). Special scoring of word-list recall data for serial position has been suggested to improve discrimination of normal aging from dementia. We examined serial position effects in word-list recall for MCI participants compared to Alzheimer patients and controls. Individuals with MCI, like Alzheimer patients, had a diminished primacy effect in recalling words from a list. No alternative scoring system was better than standard scoring of word-list recall in distinguishing MCI patients from controls. Retention weighted scoring improved the discrimination of MCI and AD groups.

MRS in relation to hippocampal volume in the oldest old.

The MRS brain metabolite ratio N-acetylaspartate (NAA)/myo-inositol (mI) is reported to be decreased in AD. MRS was used to study medial temporal and parietal regions in 60 cognitively healthy subjects older than 85 years. Subjects with small hippocampal volumes, a putative risk factor for dementia, had significantly lower NAA/mI in parietal and temporal lobes compared with other subjects. Neuropsychological tests and APOE genotype did not correlate with MRS ratios. MRS measures are candidate biomarkers for dementia risk.

Memory Complaints in Older Adults: Prognostic Value and Stability in Reporting over Time.

Objective: The purpose of this longitudinal study was to examine the prognostic value of subjective memory complaints in 156 cognitively intact community-dwelling older adults with a mean age of 83 years. Methods: Participants were assessed for subjective memory complaints, cognitive performance, functional status, and mood at annual evaluations with a mean follow-up of 4.5 years. Results: Subjective memory complaint at entry (n = 24) was not associated with impaired memory performance and did not predict memory decline or progression to incipient dementia. Memory complaints were inconsistent across examinations for 62% of participants who reported memory problems. Conclusion: Memory complaints by older adults are inconsistent over time. Memory complaints’ value as a research criterion for selecting people at risk of dementia is weak among community-dwelling older adults. Age, length of follow-up, and other population characteristics may affect the implication of self-reported memory problems.

IC-02-01: MRI evidence for a disease modifying effect of Ginkgo Biloba extract in a dementia prevention trial

Background: Decreased rates of brain volume loss are proposed as measures of “disease modifying” effects in dementia clinical trials. For dementia prevention studies, this method may be particularly important for demonstrating effects on the brain when asymptomatic. In this context we assessed whether Ginkgo Biloba extract (GBE) had an affect on rate of brain volume loss in normal elderly aged 85 and older followed in a randomized controlled trial (RCT) of dementia prevention. Methods: As part of a randomized, placebocontrolled, double-blind, 42-month study with 118 cognitively intact subjects (CDR 0) randomized to standardized GBE or placebo each subject was scanned at baseline and then during annual follow-up exams using the same 1.5 T MRI equipment. Standard volumetric MRI image analysis procedures were used to assess the volumes of total brain, ventricular volume, white matter high signal (WMH) and hippocampus. Univariate analysis compared the yearly rates of volume change between the GBE and placebo groups. A mixed effects model of the changes in each brain volume over time was used to compare differences between the two groups, adjusting for the specific baseline brain volumes, baseline intracranial volume, sex, apoE genotype, and medication adherence. Results: There was a significantly (p 0.02) lower rate of total brain volume loss in the GBE group (-0.9 1.1%/year) vs. the placebo group (-1.5 1.2%/year). The mixed model showed a significantly faster total brain loss among the placebo group (p 0.02), compared with the GBE group. There was no significant difference between the GBE and placebo treated groups in the rate of change in ventricular, WMHS or hippocampal volumes. Conclusions: GBE treatment reduced the rate of brain lost in healthy seniors. This supports the clinical efficacy data adjusted for medication adherence, shown in our previous study (Neurology, 70(9), 2008). These results suggest a “disease-modifying” effect in a RCT prevention study. Larger prevention trials with greater statistical power to observe these effects are needed to confirm these observations.