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IC‐P‐031: Medial temporal lobe changes with endovascular procedures
Author(s) -
Rosen Allyson C.
Publication year - 2015
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.2015.06.051
Subject(s) - medicine , temporal lobe , carotid arteries , dementia , carotid stenting , stroke (engine) , endovascular treatment , radiology , cardiology , disease , carotid endarterectomy , mechanical engineering , psychiatry , engineering , epilepsy , aneurysm
value ratio (SUVRs) 1.1, measured from a standard space template consisting of 6 cortical regions. For comparison to a wholecerebellar reference region, a second normalization was performed on the longitudinal data using a centrum semiovale region as a correction factor (Figure). This method has been shown to improve signal to noise, while preserving the ability to use cerebellar SUVRs at baseline. Analysis-of-Covariance models adjusted by baseline, study, treatment and age were used to assess baselineto-endpoint change between treatment and placebo groups. For sample size estimations, 80% power and a1⁄40.05 were used to detect magnitude of observed 18 month changes from baseline in the placebo group. Results:Using a whole-cerebellar reference region at baseline and endpoint, least squares mean SUVRs for the placebo group increased 0.00460.0129 (0.49%60.91), and for the active treatment group decreased 0.00660.0137 (0.19%6 0.96)(p1⁄40.62). Power analysis revealed a sample size of n1⁄44056 to detect a difference between 18 month placebo group change and baseline SUVRs (i.e. no change in treatment group from baseline). White matter adjustments resulted in a mean increase of 0.01160.0075 (0.79%60.54) in the placebo group and mean decrease of 0.00860.008 (-0.6%60.57) in the active treatment group (p1⁄40.08); the calculated sample size fell to n1⁄4421. Conclusions:Adjusting longitudinal SUVRs with a white matter reference region in these phase 3 anti-amyloid treatment trials increased mean change detection and decreased variance. This method resulted in a substantial improvement in statistical power to detect change. Reference: Abhinay Joshi, Michael Pontecorvo, Michael A. Navitsky, Ian A. Kennedy, Mark Mintun, Michael D. Devous. Measuring change in beta–amylod burden over time using florbetapir-PET and a subcortical white matter reference region. Alzheimer’s Dement. 2014;10(4):902.