MRI study of association between the SCN1A gene rs3812718 locus polymorphism and spontaneous brain activity in temporal lobe epilepsy / 中华放射学杂志

ABSTRACT

Objective:To investigate the effect of SCN1A gene polymorphism (SCN1A-rs3812718) on the alterations of spontaneous brain activity using amplitude of low-frequency fluctuations (ALFF) of MR in patients with temporal lobe epilepsy (TLE).Methods:A total of 37 TLE patients (TLE group) admitted to the Epilepsy Center of the 900th Hospital of Joint Logistic Team from March 2018 to August 2019 were retrospectively analyzed, and another 28 healthy volunteers matched for gender, age, and years of education with the TLE group were selected as the healthy control group (HC group). Sixty-five subjects were divided into four groups by genotype and diagnosis: 34 cases in AA/AG-TLE subgroup, 3 cases in GG-TLE subgroup, 20 cases in AA/AG-HC subgroup and 8 cases in GG-HC subgroup. All subjects underwent sagittal 3D-T 1WI and resting-state functional MRI using a Siemens 3.0 T Trio Tim MR scanner. Then ALFF values of the four groups were calculated using DPABI by the MATLAB 2010 platform. The ALFF values between two groups were compared by independent samples t-test. The ALFF values of different genotypes at rs3812718 locus in TLE and HC group were analyzed by multivariate analysis of variance to find out the corresponding brain regions with interaction, and then post hoc simple effect analysis was performed. Results:The ALFF values in TLE group significantly increased in left marginal lobe, left parahippocampal gyrus, left fusiform gyrus, left hippocampus, right insular lobe and right inferior temporal gyrus (Alphasim corrected P<0.001) and decreased in the left superior frontal gyrus, left middle frontal gyrus, left inferior frontal gyrus, right middle frontal gyrus, right precuneus, left precuneus, bilateral cingulate gyrus and right angular gyrus (Alphasim correction P<0.05) compared with HC group. Subjects carrying the non-risk G allele had higher ALFF values in the right inferior temporal gyrus, right fusiform gyrus, and right cerebellum than subjects carrying the risk A allele ( t=3.30, Alphasim corrected P=0.002). There was a significant interaction effect on posterior cerebellar lobe, left anterior cerebellar lobe, left inferior temporal gyrus, left superior parietal lobule and right precuneus of TLE patients with SCN1A-rs3812718 genotype. Post-hoc simple effect analysis showed that ALFF significantly increased in the left posterior cerebellar lobe, left anterior cerebellar lobe, left inferior temporal gyrus and left fusiform gyrus in GG-TLE subgroup ( t=5.97, P<0.001), but significantly decreased in the right superior parietal lobule, right precuneus, right posterior cerebellar lobe in AA/AG-TLE subgroup compared to the HC group. Compared with GG-TLE subgroup, ALFF in left posterior cerebellar lobe, left fusiform gyrus and left inferior temporal gyrus decreased in AA/AG-TLE subgroup. Conclusion:SCN1A gene polymorphism in the rs3812718 locus affects spontaneous neural activity in resting state, which may be one of the pathophysiological mechanisms of TLE.