Poor physical performance and dementia in the oldest old: the 90+ study.

Objective: To examine the cross-sectional relationship between physical performance and dementia in the oldest old (those ≥ 90 years of age).

Design: Cross-sectional study.

Setting: The 90+ Study is a population-based, longitudinal, epidemiologic study of aging and dementia performed at the University of California, Irvine, from January 1, 2003, through November 30, 2009.

Reproducibility of quantitative tractography methods applied to cerebral white matter.

Tractography based on diffusion tensor imaging (DTI) allows visualization of white matter tracts. In this study, protocols to reconstruct eleven major white matter tracts are described. The protocols were refined by several iterations of intra- and inter-rater measurements and identification of sources of variability.