Behavioral Reserve in Behavioral Variant Frontotemporal Dementia

Su Hong Kim; Yae Ji Kim; Byung Hwa Lee; Peter Lee; Ji Hyung Park; Sang Won Seo; Yong Jeong

doi:10.3389/fnagi.2022.875589

Behavioral Reserve in Behavioral Variant Frontotemporal Dementia

Front Aging Neurosci. 2022 Jun 20:14:875589. doi: 10.3389/fnagi.2022.875589. eCollection 2022.

Authors

Su Hong Kim^{1

2}, Yae Ji Kim^{2

3}, Byung Hwa Lee^{4

5

6}, Peter Lee², Ji Hyung Park¹, Sang Won Seo^{4

5

6

7

8}, Yong Jeong^{1

2

3

9}

Affiliations

¹ Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
² KAIST Institute for Health Science Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
³ Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
⁴ Department of Neurology, Samsung Medical Center, Sungkyunkwan University, Seoul, South Korea.
⁵ Neuroscience Center, Samsung Medical Center, Seoul, South Korea.
⁶ Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, South Korea.
⁷ Department of Health Science and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.
⁸ Department of Intelligent Precision Healthcare Convergence, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.
⁹ Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.

Abstract

"Reserve" refers to the individual clinical differences in response to a neuropathological burden. We explored the behavioral reserve (BR) and associated neural substrates in 40 participants with behavioral variant frontotemporal dementia (bvFTD) who were assessed with the frontal behavioral inventory (FBI) and magnetic resonance imaging. Because neuroimaging abnormality showed a high negative correlation with the FBI negative (but not positive) symptom scores, we developed a linear model only to calculate the nBR (BR for negative symptoms) marker using neuroimaging abnormalities and the FBI score. Participants were divided into high nBR and low nBR groups based on the nBR marker. The FBI negative symptom score was lower in the high nBR group than in the low nBR group having the same neuroimaging abnormalities. However, the high nBR group noted a steeper decline in cortical atrophy and showed less atrophy in the left frontotemporal cortices than the low nBR group. In addition, the fractional anisotropy (FA) values were greater in the high nBR than in the low nBR group, except in the sensory-motor and occipital areas. We identified an nBR-related functional network composed of bilateral frontotemporal areas and the left occipital pole. We propose the concept of BR in bvFTD, and these findings can help predict the disease progression.

Keywords: MRI; behavior reserve; behavioral variant frontotemporal dementia; brain network; neural correlates.