Maria Vittoria Spampinato MD, Abstract Co-Author: Nothing to Disclose

Jacobo Mintzer, Abstract Co-Author: Nothing to Disclose

James Duval Koonce MD, Presenter: Nothing to Disclose

Zoran Rumboldt MD, Abstract Co-Author: Research grant, Bracco Group Research grant, Bayer AG

Apolipoprotein epsilon 4 has been strongly linked with Alzheimer’s disease (AD). Our goal was to examine the influence of epsilon 4 allele carrier status on the rate of regional gray matter volume loss in patients with new diagnosis of AD over a twelve month period.  

Thirty Caucasian subjects (19 males, mean age 74.5 [range 58-89]) with documented conversion from mild cognitive impairment (MCI) to AD were retrospectively included and were divided into carriers (19 subjects) and non carriers of the epsilon 4 allele (11 subjects). These two groups were not significantly different in age, gender distribution, cognitive profile, and years of education. Two brain MRIs obtained at the time of the clinical conversion from MCI to AD and twelve months after the conversion were available for each subject. Volumetric magnetization prepared rapid gradient echo (MPRAGE) sequences were submitted to preprocessing (including spatial normalization, segmentation, Jacobian modulation, and smoothing) using voxel-based morphometry in statistical parametric mapping (SPM2, Welcome Department of Imaging Neuroscience). Smoothed modulated normalized gray matter maps were then submitted to statistical analysis. Comparison between longitudinal data acquired at baseline and after 12 month was conducted using paired t-test. Bonferroni correction for multiple comparisons was applied and a p-value of 0.05 was considered significant.

Epsilon 4 carriers showed significant gray matter volume loss in the bilateral hippocampi, left parietal cortex, bilateral caudate nuclei and right fronto-insular and temporal cortex during the first year after the clinical diagnosis of AD. There were no significant changes in gray matter volume in non carriers of the epsilon 4 allele during the first year after clinical conversion from MCI to AD.

Prior clinical longitudinal studies have shown that epsilon 4 carrier status is associated with more rapid cognitive decline in AD. We found that also the rate of gray matter atrophy in certain brain areas may be increased in epsilon 4 carriers compared to non carriers during the first year after MCI to AD conversion.

Understanding the role of apolipoprotein epsilon 4 as a causative factor in neurodegeneration is important because therapies targeting the structure and function of apoE are under investigation.

Spampinato, M, Mintzer, J, Koonce, J, Rumboldt, Z, Correlation between Apolipoprotein Epsilon Genotype and Regional Gray Matter Volume Loss with Voxel-based Morphometry: One-year Follow-up after Conversion from Mild Cognitive Impairment to Alzheimer’s Disease.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016073.html