Longitudinal brain atrophy and its relationship with semantic function deterioration in a cohort of Chinese patients with semantic dementia

Abstract

Event Abstract Back to Event Longitudinal brain atrophy and its relationship with semantic function deterioration in a cohort of Chinese patients with semantic dementia Qing Yang1*, Keliang Chen1, Yingru Lv1, Yanchao Bi2* and Guo Qihao3* 1 Huashan Hospital, Fudan University, China 2 State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China 3 Shanghai Sixth People's Hospital, China Semantic dementia (SD), also known as the semantic variant of primary progressive aphasia (svPPA), is a neurodegenerative disorder characterized by profound and progressive semantic impairment, while other cognitive domains are relatively preserved at least during the early stage[1-3]. Cross-sectional studies have repeatedly related SD to local gray matter atrophy, mainly involving the bilateral anterior temporal lobes and adjacent brain regions[4-9]. However, the critical sites of brain atrophy associated with semantic deficits are still debated, partly because of the relative lack of longitudinal studies illustrating the relationship between brain atrophy progression and longitudinal semantic deterioration in this disease[10]. In this study, we explored the relationship between the extent of longitudinal brain atrophy progression and the degree of semantic deterioration in 11 Chinese patients with SD over one year. We found that the patients’ semantic deterioration was positively associated with gray matter reduction, mainly in the bilateral temporal and parietal lobes, including the bilateral inferior, middle, and superior temporal gyrus, temporal pole, Heschl gyrus, precuneus, and angular gyrus, as well as in subcortical regions (such as the thalamus and putamen). Interestingly, these areas were located more posteriorly than the brain regions most commonly identified as critical regions of the semantic deficits in SD patients (i.e., the anterior temporal lobes). We interpret this finding as supportive evidence that during the progression of SD, longitudinal structural damage in the more posterior regions of the temporal lobes (not just further damage in the anterior temporal lobes) may play an important role in the behavioral deterioration seen in this neurodegenerative disorder. Figure 1 Acknowledgements This work was supported by the 973 Program (2014CB846100), the National Natural Science Foundation of China (81171019, 31271115), the Major Project of National Social Science Foundation (13&ZD188), the Fundamental Research Funds for the Central Universities (2017XTCX04), and the Shanghai Sailing Program (19YF1405200).