Diagnostic accuracy of statistical pattern recognition of electroencephalogram registration in evaluation of cognitive impairment and dementia.

BACKGROUND: There is still a need for simple, noninvasive, and inexpensive methods to diagnose the causes of cognitive impairment and dementia. In this study, contemporary statistical methods were used to classify the clinical cases of cognitive impairment based on electroencephalograms (EEG). METHODS: An EEG database was established from seven different groups of subjects with cognitive impairment and dementia as well as healthy controls. A classifier was created for each possible pair of groups using statistical pattern recognition (SPR). RESULTS: A good-to-excellent separation was found when differentiating cases of degenerative disorders from controls, vascular disorders, and depression but this was less so when the likelihood of comorbidity was high. CONCLUSIONS: Using EEG with SPR seems to be a reliable method for diagnosing the causes of cognitive impairment and dementia, but comorbidity must be taken into account.

The Association Between Midlife Physical Activity and Depressive Symptoms in Late Life: Age Gene/Environment Susceptibility-Reykjavik Study.

BACKGROUND: There is little evidence on the long-term association between physical activity (PA) and depressive symptoms in old age. We examined the association of midlife PA and depressive symptoms in late life. METHODS: A large community-based population residing in Reykjavik, Iceland, participated in a longitudinal study with an average of 25 years of follow up. Midlife PA was categorized as active and inactive groups (n = 4,140, Active = 1,292, Inactive = 2,848, mean age 52±7 years). The main outcome had six or higher depressive symptoms assessed by the 15-item Geriatric Depression scale. Participants who had a history of depression (n = 226), and were diagnosed with dementia (n = 393), and had incomplete cognitive data (n = 595) and incomplete analytical data (n = 422) were excluded. Level of weekly PA was ascertained by a questionnaire at midlife. Depressive symptoms were assessed on average 25 (±4) years later. RESULTS: After controlling for demographic and health-related risk factors, those who were active at midlife were less likely to have high level of depressive symptomatology (6 or higher Geriatric Depression scale scores, odds ratio = 0.58, 95% confidence interval: 0.41-0.83, p < .005) compared with those who were inactive in midlife. After full adjustment of three domains of late-life cognitive function the results remained significant (odds ratio = 0.61, 95% confidence interval: 0.43-0.86, p = .005). CONCLUSION: Our study shows that midlife PA is associated with lower depressive symptoms 25 years later. Participating in regular PA in midlife may improve mental health in late life.

Midlife physical activity preserves lower extremity function in older adults: age gene/environment susceptibility-Reykjavik study.

OBJECTIVES: To examine the long-term association between midlife physical activity (PA) and lower extremity function (LEF) in late life. DESIGN: Longitudinal study with an average of 25 years of follow-up. SETTING: Community-dwelling old population in Reykjavik, Iceland. PARTICIPANTS: Four thousand seven hundred fifty-three community-dwelling men and women (mean age 76 ± 6) in Reykjavik, Iceland. MEASUREMENTS: On the basis of weekly hours of regular PA reported at the midlife examination, participants were classified as active or inactive. Measures of LEF in late life were gait speed on a 6-m walk, Timed Up and Go (TUG), and knee extension (KE) strength tests. Linear regression analysis was used to examine the association. RESULTS: Participants who were active in midlife had significantly better LEF (faster gait speed, ß = 0.50, P ≤ .001; faster TUG time, ß = -0.53 P ≤ .001; stronger KE strength, ß = 1.3, P ≤ .001) in late life than those who were not active in midlife after adjusting for sociodemographic and cardiovascular risk factors. After adjustment for cognitive function in late life (speed of processing, memory, and executive function), participants who were active in midlife had significantly faster gait speed (ß = 0.04, P ≤ .001), faster TUG time (ß = -0.34, P ≤ .001), and greater KE strength (ß = 0.87, P ≤ .001) in old age than those who were not active in midlife. CONCLUSION: Regular PA in midlife is associated with better performance of LEF in later life, even after controlling for late-life cognitive function.