Brain Resting State-functional Magnetic Resonance Study In Idiopathic Generalized Epilepsy

Objective:Using fractional amplitude of low frequency fluctuation(fALFF), regional homogeneity(ReHo) and functionnal connectivity(FC) method to observe the changes of brain function and functional network in idiopathic generalized epilepsy(IGE), and to explore the the whole brain functional activity features of IGE and the^correlation between abnormal brain regions and clinical manifestation, to improve the understanding of its Neuro pathophysiological mechanisms.Methods:23 cases of idiopathic generalized epilepsy patients (IGE group) and 23 health controls (HC group) who were matched in age, gender and education level. The patient group were diagnosed by neurological expert according to the diagnostic criteria of International League Against Epilepsy(ILAE). Using the Holland PHILIPS Achieva 3.0T TX superconducting MRI scanner and 8 channel phase front head circle for regular whole brain scan, three-dimensional brain structure scans and resting-state functional magnetic resonance imaging (RS-fMRI) scan. Pre-processing the RS-fMRI data and analysis data by fALFF, ReHo, FC methods in DPARSF software. Independent sample T-test between the general data of two groups were performed by SPSS 17.0. Two sample T-test between RS-fMRI (fALFF, ReHo and FC) data of two groups, and correlation analysis between different brain regions in RS-fMRI results of IGE patients with the course of disease were performed by REST software (age, gender and education level as the convariant).Results:1 fALFF analysis:Compared with normal controls, IGE group showed significantly increasd fALFF in bilateral precentral gyrus, left cingulate gyrus, left paracentral lobule, left supplementary motor area, left superior occipital gyrus, left middle occipital gyrus, left calcarine cortex, right precuneus; decreased in bilateral inferior temporal gyrus, right parahippocampa gyrus, right insula, right precuneus and left inferior parietal lobule. The fALFF value dfferences of the two groups was showed in the statistical parametric mapping by AlphaSim correction (the threshold was set at p <0.005, cluster size≥26).2 ReHo analysis:Compared with normal controls, IGE group showed significantly increasd ReHo in left calcarine cortex, left superior parietal lobule, left postcentral gyrus, right precentral gyrus; decreased in right fusiform gyrus, left lentiform nucleus, right inferior frontal gyrus, right superior medial frontal gyrus, left middle occiptal gyrus, right insula and bilateral inferior parietal lobule. The ReHo value dfferences of the two groups was showed in the statistical parametric mapping by AlphaSim correction (the threshold was set at p<0.005, cluster size≥26).3 FC analysis:Selected the bilateral thalamus as the regions of interest, Compared with normal controls, IGE group showed significantly increasd FC in midbrain, bilateral posterior limb of internal capsule and right caudate nucleus; brain regions with decreasd FC has not been found. The FC value dfferences of the two groups was showed in the statistical parametric mapping by AlphaSim correction (the threshold was set at p<0.01, cluster size≥40).4 These different brain regions in fALFF, ReHo and FC results of IGE patients were no correlated with the course of disease.Conclusion:IGE patients had some brain areas with abnormal changes in fALFF, ReHo and FC, which suggested the changes of neuronal activity intensity, synchronization and functional network in these brain regions, it shows that the long-term epileptiform discharge may lead to changes in brain function; these changes may related with tonic seizure, myoclonic and absence seizures, and may related with disturbance of consciousness, mental mental and motor dysfunction when IGE patients seizures. This wide range of brain areas with abnormal changes in function is the basis of the IGE complex clinical manifestations of the nerve.Combined application of three analysis methods (fALFF, ReHo and FC) of RS-fMRI can evaluate the change of brain function in resting state, also make for exploring the damages of neural and functional network in IGE. It can be better for provides functional neuroanatomical evidence for the researches on Neuro pathogenesis mechanism of IGE.