Objective:To investigate the effects of apolipoprotein E (APOE) ε4 allele on β-amyloid (Aβ) deposition in subcortical structures and functional connectivity (FC) between brain regions in patients with Alzheimer′s disease (AD). Methods:Forty-three patients with probable mild/moderate AD were prospectively enrolled from the First Medical Centre, Chinese PLA General Hospital between January 2023 and October 2023, including 23 APOE ε4+ patients (12 males and 11 females, age (74.8±8.4) years), 20 APOE ε4- patients (14 males and 6 females, age (77.6±8.9) years) and 20 normal cognitive volunteers (NC) (15 males and 5 females, age (75.3±6.2) years). All subjects underwent 11C-Pittsburgh compound B (PIB) PET/MR brain imaging. The differences of gray matter volume (GMV) in subcortical structures (hippocampus, amygdala) among the three groups were analyzed by one-way analysis of variance and least significant difference (LSD) t test. Independent-sample t test and Pearson correlation analysis were used to analyze difference in Aβ deposition between APOE ε4+ patients and APOE ε4- patients, and the correlation between subcortical structure and brain FC. Results:The GMV of bilateral amygdala between NC group and APOE ε4+ gene carrier group, and between APOE ε4+ and APOE ε4- gene carrier groups were significantly different ( F=6.43, P=0.002; P values: 0.002, 0.003). Significant difference of GMV was observed in the bilateral hippocampus among three groups ( F=5.34, P=0.030). Abnormal PIB uptake was detected in both the hippocampus and amygdala of both APOE ε4+ and APOE ε4- gene carrier groups, with a more pronounced effect observed in the APOE ε4+ group ( t values: 3.14, 2.19, P values: 0.032, 0.009). Taking the hippocampus as the seed point, there was no obvious abnormality in the whole brain connectivity map among APOE ε4+, APOE ε4- carriers and NC groups. With the amygdala as the seed point, the whole brain connectivity in the APOE ε4+ gene carrier group was significantly reduced, and the connectivity between the amygdala and the cingulate gyrus, parietal lobe and temporal lobe was significantly reduced in the APOE ε4+ gene carrier group compared with NC group, while the connectivity between the amygdala and the whole brain was not significantly reduced in the APOE ε4- gene carrier group. Aβ deposition in amygdala was positively correlated with FC coefficients of frontal brain regions, gyrus rectus, right middle occipital gyrus and left temporal lobe ( r values: 0.56-0.70, all P<0.05). Conclusion:APOE influences GMV and Aβ deposition of hippocampus and amygdala, and FC of amygdala, and may be involved in the pathological mechanism of cognitive impairment.

Objective:To explore the correlation between imaging features of children with tic disorders and their features assessed by the Yale Global Tic Severity Scale (YGTSS).Methods:A retrospective study.A total of 33 children with tic disorders treated in the Department of Child Rehabilitation, the First Affiliated Hospital of Xinxiang Medical University from January 2022 to March 2023 were included in the tic disorder group, and 10 healthy age-matched children received physical examination during the same period were included in the healthy control group.Under the functional positioning of functional magnetic resonance imaging (fMRI), the active area of children with tic disorders at varying degrees was found.In the region of interest (ROI), localization monitoring and diffusion tensor imaging (DTI) were performed, and the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were recorded.In the same ROI (bilateral thalamus, genu of internal capsule, splenium of corpus callosum, globus pallidus, caudate nucleus) of children in healthy control group, ADC and FA were recorded.Imaging data were compared between groups using the independent sample t test, and their correlation with YGTSS scores was identified by the Pearson correlation analysis. Results:There were significant differences in ADC of the left thalamus (0.869±0.077 vs.0.794±0.083, P=0.022), the right thalamus (0.853±0.055 vs.0.798±0.054, P=0.014), the left caudate nucleus (0.871±0.121 vs.0.787±0.052, P=0.003) and the right caudate nucleus (0.856±0.075 vs.0.788±0.063, P=0.010) between tic disorder group and healthy control group.No significant differences were detected in ADC of the remaining ROI between groups (all P>0.05). There were significant differences in FA of the left thalamus (0.259±0.050 vs.0.344±0.077, P=0.007), the right thalamus (0.265±0.057 vs.0.347±0.095, P=0.026) and the right caudate nucleus (0.168±0.118 vs.0.309±0.181, P=0.041) between tic disorder group and healthy control group.No significant differences were detected in ADC and FA between children with mild and moderate tic disorders (all P>0.05). ADC of the left thalamus and the right caudate nucleus were significantly correlated with YGTSS scores in children with tic disorders ( r=0.407 and 0.372, respectively; all P<0.05). FA of the right thalamus was negatively correlated with YGTSS scores in children with tic disorders ( r=-0.439, P<0.05). Conclusions:ADC of the thalamus and caudate nucleus, and FA of the right thalamus are significantly correlated with YGTSS scores of children with tic disorders.High ADC of the left thalamus and the right caudate nucleus are correlated with high YGTSS scores, indicating a severe symptom of tic disorder in children.A high FA of the right thalamus is correlated with low YGTSS scores, indicating a mild symptom of tic disorder in children.