[Abstract Title]. - Society for Neuroscience

Methods: Subjects in the present study included a sample of young controls (YC, N=142, age 18-
30), older controls (OC, N=87, age 65-94) and AD patients (N=29, age 66-96). Previously
conducted exploratory analyses identified a set of regions of interest (ROIs) of cortical thinning
in both aging and AD. Mean thickness values within these ROIs were used to calculate percent
thinning due to aging or AD.
Results: Specific regions identified from the “cortical signature of aging” were predominantly
affected by age and minimally more by AD. For example, the calcarine cortex exhibited 22%
thinning in OC vs. YC with an additional 3.8% when comparing AD to OC. Other regions
identified from the “cortical signature of AD” were predominantly affected by AD with minimal
effects of age. For example, the inferior temporal cortex exhibited only 1.2% thinning in OC vs.
YC with an additional 11.8% thinning in AD vs. OC. Finally, other regions were affected by
both aging and AD. For example, the supramarginal gyral cortex showed 8.4% thinning in aging
and an additional 8.4% thinning in AD.
Conclusions: The processes of aging and AD have both differential and partially overlapping
effects on specific regions of the cerebral cortex. Further work is warranted to determine the
behavioral and clinical relevance of these findings.
Disclosures: A. Bakkour , None; J.C. Morris, None; R.L. Buckner, None; B.C. Dickerson,
None.
Poster
246. Alzheimer's Imaging and Biomarkers II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 246.8/P12
Topic: C.01.o. Imaging and biomarkers
Support: NIA Grants R01-AG29411, R21-AG029840, and K23-AG22509
MIND Institute
NCRR Grants P41- RR14075 and U24-RR021382
Title: Temporal pole anatomy and semantic deficits in primary progressive aphasia
Authors: D. SAPOLSKY, A. BAKKOUR, A. NEGREIRA, *B. C. DICKERSON;
Dept Neurol, Massachusetts Gener Hosp., Charlestown, MA
Abstract: Objective: Although the functional role of the temporal pole in semantic processing
has been illuminated through studies of groups of patients with focal lesions and