[Altered dynamics of brain spontaneous activity in betel quid dependence chewers]

Objective: To investigate the dynamic characteristics of brain spontaneous activity in betel quid dependence (BQD) chewers and its relationship with clinical indexes. Method: This study was conducted in Hainan General Hospital from April to December 2019 and the data of 53 BQD chewers (37 males and 16 females, aged 20 to 58(38±11) years) and 37 healthy controls (HC) (24 males and 13 females, aged 23-57(42±12) years) were collected. All these subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) scan. The dynamic characteristics of resting fMRI indexes, including dynamic amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo) and degree centrality (DC) of these subjects were calculated using the sliding time window method, parameters such as age and dynamic local consistency were analyzed and compared between the two groups. Pearson correlation was used to analyze the relationship between dynamic indexes, betel quid dependence score (BQDS) and disease duration in BQD group. Results: BQD chewers showed decreased dynamic ALFF in the left orbital prefrontal cortex (0.138±0.041 vs 0.171±0.070), the right temporal pole superior temporal gyrus (0.277±0.070 vs 0.319±0.086) and the right inferior parietal lobule (0.223±0.052 vs 0.259±0.088) than HC (all P<0.05). For regional homogeneity, BQD chewers showed a decrease dynamic ReHo in the right inferior temporal gyrus (0.055±0.008 vs 0.061±0.009), the orbital prefrontal cortex (0.058±0.005 vs 0.063±0.008), the right inferior frontal gyrus (0.081±0.006 vs 0.087±0.011), the right superior occipital gyrus (0.056±0.007 vs 0.062±0.008), the left precentral gyrus (0.068±0.008 vs 0.074±0.008), and the left superior frontal gyrus (0.058±0.008 vs 0.064±0.009) than HC (all P<0.05). BQD chewers showed an increase dynamic ReHo in the right precuneus (0.095±0.009 vs 0.089±0.008) (P<0.05). There was no significant difference in DC between the two groups (all P>0.05). The relationships between three dynamic ALFF and BQDS (r=-0.104, -0.015, -0.119), seven dynamic ReHo and BQDS (r=-0.099, -0.141, -0.055, -0.078, -0.027, -0.111, -0.090), three dynamic ALFF and disease duration (r=-0.122, -0.095, -0.171), and seven dynamic ReHo and disease duration (r=0.242, -0.252, 0.035, 0.056, 0.047, 0.081, 0.169) were not statistically significant (all P>0.05). Conclusions: BQD chewers showed a decrease dynamic ReHo and/or ALFF in multiple brain regions dominated by prefrontal cortex, and an increase dynamic ReHo in the right precuneus.