Objective-Examine the correlation of cardiorespiratory fitness with brain atrophy and cognition in early-stage Alzheimer's disease (AD).Background-In normal aging physical fitness appears to mitigate functional and structural agerelated brain changes. Whether this is observed in AD is not known.

Neuroimaging studies of apolipoprotein E (APOEε4) have implicated its association with brain atrophy in Alzheimer's disease. To date, few studies have used automated morphological analysis techniques to assess APOEε4-related brain structure change in both gray and white matter in nondemented older adults. Nondemented (CDR = 0, n = 53) subjects over 60 had MRI, diffusion tensor imaging, and neurocognitive assessments. We assessed differences in cognition and brain structure associated with APOEε4 genetic variation using voxel-based morphometry techniques, and tract-based spatial statistics of fractional anisotropy change. In nondemented older adults with the ε4 allele, cognitive performance was reduced, and atrophy was present in the hippocampus and amygdala compared to APOEε4 negative participants. We also report that ε4 carriers have decreased fractional anisotropy in the left parahippocampal gyrus white matter. In conclusion, the presence of an APOEε4 allele in nondemented older adults is associated with decreases in cognition and gray and white matter changes in the medial temporal cortex. Overall we provide further evidence of the effects of genetic variance related to imaging and cognitive measures of risk for Alzheimer's disease.

Exercise and cardiorespiratory (CR) fitness may moderate age-related regional brain changes in nondemented older adults (ND). The relationship of fitness to Alzheimer's disease (AD) related brain change is understudied, particularly in the hippocampus which is disproportionately affected in early AD. The role of apolipoprotein E4 (apoE4) genotype in modulating this relationship is also unknown. Nondemented (n=56) and early-stage AD subjects (n=61) over age 65 had MRI and CR fitness assessments. Voxel-based morphometry (VBM) techniques were utilized to identify AD-related atrophy. We analyzed the relationship of CR fitness with white and gray matter within groups, assessed fitness-related brain volume change in areas most affected by AD-related atrophy, and then analyzed differential fitness-brain relationships between apoE4 carriers. Atrophy was present in the medial temporal, temporal, and parietal cortices in subjects with mild AD. There was a significant positive correlation of CR fitness with parietal and medial temporal volume in AD subjects. ND subjects did not have a significant relationship between brain volume and CR fitness in the global or SVC analyses. There was not a significant interaction for fitness × apoE4 genotype in either group. In early-stage AD, cardiorespiratory fitness is associated with regional brain volumes in the medial temporal and parietal cortices suggesting that maintaining cardiorespiratory fitness may modify ADrelated brain atrophy.

Our data suggest that strict supine positioning during STN DBS surgery results in minimal intracranial air and is not associated with VAE or symptomatic intracranial hemorrhage when the operative method described is used.

Arterial embolization in patients with angiographically NBU is as safe and effective as embolization in patients with BU.