Title:Comparing Medial Temporal Atrophy Between Early-Onset Semantic
Dementia and Early-Onset Alzheimer's Disease Using Voxel-Based Morphometry:
A Multicenter MRI Study
Volume: 19
Issue: 7
Author(s): Ryota Kobayashi*, Hiroshi Hayashi, Shinobu Kawakatsu, Yuzuru Shibuya, Daichi Morioka, Makoto Ohba, Masanori Yoshioka, Kazutaka Sakamoto, Masafumi Kanoto and Koichi Otani
Affiliation:
- Department of Psychiatry, Yamagata University School of Medicine, Iidanishi 2-2-2, Yamagata 990-9585, Japan
Keywords:
Alzheimer’s disease, early-onset dementia, magnetic resonance, imaging, semantic dementia, semantic variant, primary progressive aphasia, voxel-based morphometry.
Abstract:
Background: Early-onset Semantic dementia (EOSD) and early-onset Alzheimer's disease
(EOAD) are often difficult to clinically differentiate in the early stages of the diseases because of the
overlaps of clinical symptoms such as language symptoms. We compared the degree of atrophy in
medial temporal structures between the two types of dementia using the voxel-based specific regional
analysis system for Alzheimer’s disease (VSRAD).
Methods: The participants included 29 (age: 61.7±4.5 years) and 39 (age: 60.2±4.9 years) patients
with EOSD and EOAD, respectively. The degree of atrophy in medial temporal structures was quantified
using the VSRAD for magnetic resonance imaging data. Receiver operating characteristic
(ROC) analysis was performed to distinguish patients with EOSD and EOAD using the mean Z score
(Z-score) in bilateral medial temporal structures and the absolute value (laterality score) of the laterality
of Z-score (| right–left |) for indicating the degree of asymmetrical atrophy in medial temporal
structures.
Results: The EOSD group had significantly higher Z and laterality scores than the EOAD group (Zscores:
mean ± standard deviation: 3.74±1.05 vs. 1.56±0.81, respectively; P<0.001; laterality score:
mean ± standard deviation: 2.35±1.23 vs. 0.68±0.51, respectively; P<0.001). In ROC analysis, the
sensitivity and specificity to differentiate EOSD from EOAD by a Z-score of 2.29 were 97% and
85%, respectively and by the laterality score of 1.05 were 93% and 85%, respectively.
Conclusion: EOSD leads to more severe and asymmetrical atrophy in medial temporal structures
than EOAD. The VSRAD may be useful to distinguish between these dementias that have several
clinically similar symptoms.
