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P3–104: Do microbleeds predict stroke in Alzheimer's disease (MISTRAL)? Study design and first results
Author(s) -
Benedictus Marije,
Goos Jeroen,
Prins Niels,
Scheltens Philip,
Barkhof Frederik,
Van der Flier Wiesje
Publication year - 2013
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2013.05.1175
Subject(s) - medicine , hazard ratio , cerebral amyloid angiopathy , dementia , stroke (engine) , proportional hazards model , antithrombotic , population , cohort , cardiology , confidence interval , disease , mechanical engineering , environmental health , engineering
(PCC) and precuneus. However, the relationship between functional connectivity and PCC volume is not well known. We hypothesized that there is no linear relationship between anatomy and functional connectivity because of possible functional compensatory mechanisms which increase connectivity in early neurodegeneration. Methods: We evaluated 17 patients with mild AD and 24 healthy controls matched for gender and age. All subjects underwent a 10 minutes task-free fMRI at 3.0T. To identify the DMN, seed-based functional connectivity was calculated by placing a seed in the PCC and later calculated a Fisher’s r-to-z transformation to obtain DMN statistical z-score maps. We also performed automatic volumetry of PCC by using Freesurfer software (version 5.0.1). We compared PCC volume and DMNmean connectivity between groups. Then, to verify if there is a correlation between, we performed simple linear as well as quadratic regressions between these values. Results: We found significant differences both in DMN connectivity and PCC volumes between mild AD and controls (p<0.001). We did not find significant correlations between these variables when simple linear regressions were carried out. However, when we performed quadratic regressions, we found a significant correlation between these variables in mild AD group (p 1⁄4 0.003, R-squared1⁄4 0.56 Figure 1), but not in normal aging group.Conclusions:Our findings suggest that there is a non-linear relationship between PCC volumetry and DMN connectivity in mild AD. This result might reflect an early increase in connectivity when the neurodegenerative process starts. With the progression of atrophy, connectivity also tends to decrease. Other factors may have influenced this relationship, like age and cognitive reserve.