Faculty Bibliography

Background: Subjective Cognitive Impairment (SCI), Global Deterioration Scale stage 2, is common in older persons. A study of otherwise healthy persons found that 54% of SCI subjects followed over 7 years progressed toMild Cognitive Impairment (MCI) or dementia (Reisberg, et al., Alzheimer's & Dementia, 2010).1 Medications may contribute to SCI occurrence, however, their influence on SCI outcome is largely unknown. Therefore, we investigated the impact of medications subsequently associated with dementia risk in our previously characterized cohort.1 Methods: Subjects with SCI at baseline from our 2010 publication1 were studied. These subjects had baseline evaluations between 1/1/1984 and 12/31/1997 and were followed until 12/31/2001. Medication data was available on 143 of 166 subjects. Subjects receiving topical estrogen at the baseline evaluationwere excluded fromthese analyses. At baseline, evaluable subjects (N = 140; 91 women, 49 men) had a mean age of 66.5 +/- 8.4 years; 15.6 +/- 2.7 years of education; and MMSE scores of 29.0 +/- 1.2. Twenty-two women (24.2%) were receiving HRT, comprising estrogen (n = 10) or estrogen-progesterone combination (n = 12). Results: Subjects were followed over 7.0 +/- 3.4 years. Increased age and education were associated with clinical progression in this cohort (OR = 1.06 and 0.78 respectively; p-values < 0.05). Three of ten estrogenonly (30%) subjects progressed (2 to MCI, 1 to dementia); seven of twelve estrogen-progesterone (58.3%) subjects progressed (6 toMCI, 1 to dementia). In the total HRT group, 45.5% progressed, whereas in the control group (no-HRT), 62 of 118 progressed (52.5%), (49 to MCI, 13 to dementia). Age, education and gender did not differ significantly between subjects in the study groups (t-test and chi-square p-values, NS). Multivariate logistic regression for each condition was performed investigating differences in therapy, age, gender and education. Therapy was not associated with progression status. Conclusions: HRT did not influence 7-year outcome in SCI subjects. Therefore, SCI subjects were not particularly sensitive to reported deleterious effects of HRT on progression of cognitive decline. Systematic longitudinal investigation of possible effects of other medications/conditions on progression of SCI to MCI/dementia is required to identify substances that may regulate/prevent this process

BACKGROUND: Subjective cognitive impairment (SCI) in older persons without manifest symptomatology is a common condition with a largely unclear prognosis. We hypothesized that (1) examining outcome for a sufficient period by using conversion to mild cognitive impairment (MCI) or dementia would clarify SCI prognosis, and (2) with the aforementioned procedures, the prognosis of SCI subjects would differ significantly from that of demographically matched healthy subjects, free of SCI, termed no cognitive impairment (NCI) subjects. METHODS: A consecutive series of healthy subjects, aged > or =40 years, presenting with NCI or SCI to a brain aging and dementia research center during a 14-year interval, were studied and followed up during an 18-year observation window. The study population (60 NCI, 200 SCI, 60% female) had a mean age of 67.2 +/- 9.1 years, was well-educated (mean, 15.5 +/- 2.7 years), and cognitively normal (Mini-Mental State Examination, 29.1 +/- 1.2). RESULTS: A total of 213 subjects (81.9% of the study population) were followed up. Follow-up occurred during a mean period of 6.8 +/- 3.4 years, and subjects had a mean of 2.9 +/- 1.6 follow-up visits. Seven NCI (14.9%) and 90 SCI (54.2%) subjects declined (P < .0001). Of NCI decliners, five declined to MCI and two to probable Alzheimer's disease. Of SCI decliners, 71 declined to MCI and 19 to dementia diagnoses. Controlling for baseline demographic variables and follow-up time, Weibull proportional hazards model revealed increased decline in SCI subjects (hazard ratio, 4.5; 95% confidence interval, 1.9-10.3), whereas the accelerated failure time model analysis with an underlying Weibull survival function showed that SCI subjects declined more rapidly, at 60% of the rate of NCI subjects (95% confidence interval, 0.45-0.80). Furthermore, mean time to decline was 3.5 years longer for NCI than for SCI subjects (P = .0003). CONCLUSIONS: These results indicate that SCI in subjects with normal cognition is a harbinger of further decline in most subjects during a 7-year mean follow-up interval. Relevance for community populations should be investigated, and prevention studies in this at-risk population should be explored

BACKGROUND: Subjective cognitive impairment (SCI) has been a common, but poorly understood condition, frequently occurring in older persons. METHODS: The past and the emerging literature on SCI and synonymously named conditions is reviewed. RESULTS: Findings include: (1) There is support from at least one longitudinal study for a long-standing concept of SCI as a pre-mild cognitive impairment (MCI) condition lasting approximately 15years. (2) There are complex relationships between SCI and depression and anxiety. (3) Differences in SCI subjects from age-matched non-SCI persons are being published in terms of cognitive tests, hippocampal gray matter density, hippocampal volumes, cerebral metabolism, and urinary cortisol levels. Psychometric and dementia test score differences between SCI and MCI subjects have long been evident. (4) Predictive electrophysiologic features of subsequent decline in SCI subjects are being published. CONCLUSIONS: Studies of therapeutic agents in SCI treatment and resultant Alzheimer's disease prevention appear to be feasible. These trials are also necessary from a public health perspective

An extensive literature reports changes in quantitative electroencephalogram (QEEG) with aging and a relationship between magnitude of changes and degree of clinical deterioration in progressive dementia. Longitudinal studies have demonstrated QEEG differences between mild cognitively impaired (MCI) elderly who go on to decline and those who do not. This study focuses on normal elderly with subjective cognitive complaints to assess the utility of QEEG in predicting future decline within 7 years. Forty-four normal elderly received extensive clinical, neurocognitive and QEEG examinations at baseline. All study subjects (N = 44) had only subjective complaints but no objective evidence of cognitive deficit (evaluated using the Global Deterioration Scale [GDS] score, GDS stage = 2) at baseline and were re-evaluated during 7-9 year follow-up. Baseline QEEGs of Decliners differed significantly (p < 0.0001, by MANOVA) from Non-Decliners, characterized by increases in theta power, slowing of mean frequency, and changes in covariance among regions, especially on the right hemisphere. Using logistic regression, an R2 of 0.93 (p < 0.001) was obtained between baseline QEEG features and probability of future decline, with an overall predictive accuracy of 90%. These data indicate high sensitivity and specificity for baseline QEEG as a differential predictor of future cognitive state in normal, subjectively impaired elderly