Brain volume and survival from age 78 to 85: the contribution of Alzheimer-type magnetic resonance imaging findings.

OBJECTIVES: To test the prediction of survival using magnetic resonance imaging (MRI)-derived global and regional brain volumes in subjects aged 78 to 79 without dementia. DESIGN: Observational follow-up study. SETTING: University teaching hospital. PARTICIPANTS: Participants born in 1921, recruited in 1997/98 to a longitudinal study, who underwent brain MRI in 1999/2000. MEASUREMENTS: Vital status on May 12, 2006, global and regional brain volumes. RESULTS: Thirty-seven of 98 (34.9%) participants died during follow-up. After adjustment for cognitive ability at time of MRI examination, childhood intelligence, sex, hypertension, smoking history, obesity, hyperlipidemia, and age at MRI, proportion of intracranial volume occupied by the brain (brain fraction) predicted death before age 85 (P=.04). Participants with brain fraction less than 0.726 had more than twice the relative risk (2.8, 95% confidence interval=1.1-7.3) of death than participants with brain fraction greater 0.726. Lower survival was significantly associated with lower gray matter volumes in bilateral parietal and left frontoparietal areas and with lower white matter volumes in left parietal and right posterior temporal regions. Cox regression analysis showed that parietal white matter volume (P=.003), a subsequent diagnosis of dementia (P<.001), and sex (P=.004) were independent predictors of survival. CONCLUSION: In participants aged 78 to 79, a lower global brain fraction predicted survival to approximately age 85. Smaller regional volumetric brain reductions, seen in Alzheimer's disease (AD), also predicted survival independent of dementia. The presence of prodromal AD probably explain the main findings.

Emotion perception in Alzheimer's disease and mood disorder in old age.

Difficulties in understanding emotional signals might have important implications for social interactions in old age. In this study we investigated emotion perception skills involved in decoding facial expressions of emotion in healthy older adults, compared with those with Alzheimer's disease (AD) or late-life mood disorder (MD). Although those with MD were mildly impaired in identifying emotional expressions, this was not caused by negative biases in choosing labels. Emotion decoding performance in AD was much more impaired, particularly when relatively subtle expressions were presented. Difficulties in choosing between labels to describe an emotional face were predicted by executive dysfunction, whereas impaired ability to match 2 emotional faces was related to general difficulties with face perception. Across all 3 groups, problems with emotion perception predicted quality of life independently of variance predicted by cognitive function and mood, indicating the potential importance of emotion decoding skills in the well-being of older adults.