White Matter Alterations In Medial Temporal Lobe Epilepsy Of Partial Seizures And Secondary Generalized Tonic-clonic Seizures

Objective:This study aimed to investigate the differences of white matter alterations between partial seizures(PS)in medial temporal lobe epilepsy with unilateral hippocampal sclerosis(mTLE-HS)and secondary generalized tonic-clonic seizures(sGTCS)by using diffusion tensor imaging(DTI)technique,then to explore the two seizures'different structure bases,and explore the relationship with the onset age,course of disease,attack frequency.Methods:All of DTI images were obtained on a MRI scanner(3.0 Tesla).Thirty unilateral mTLE-HS patients,including 14 PS patients and 16 sGTCS patients,and twenty age and gender-matched healthy control subjects were recruited.The white matter in the same side of lesion was defined as "ipsilateral" white matter.The intergroup differences of white matter among 3 groups were performed as well as the differences between the white matter of ipsilateral and contralateral hemispheres.FA in sGTCS and PS were compared with the course of disease,the age of onset and the attack frequency in recent three years by correlation analysis,P<0.05 was considered as statistically significant.Results:Compared with the healthy controls,the PS patients showed decreased FA and increased MD,RD in ipsilateral cingulate cortex(hippocampus),inferior longitudinal fasciculus(ILF),uncinate fasciculus(UF).We also observed extensive alterations of white matter in sGTCS patients,including decreased FA and increased MD,RD in bilateral anterior thalamicradiation(ATR),corticospinal tract(CT),cingulate cortex(CC),corpus callosum,inferior fronto-occipital fasciculus(IFOF),ILF,superior longitudinal fasciculus(SLF),uncinate fasciculus(UF).Compared with PS patients,sGTCS patients showed that MD in bilateral ATR,ipsilateral CT,CC(hippocampus),IFPF and contralateral SLF was increased,as the same as RD and AD.Compared with contralateral white matter respectively,the ipsilateral ATR,CC(hippocampus),IFOF,ILF,UF,SLF(temporal part)in sGTCS patients and ILF,UF in PS patients showed significantly white matter alterations(P<0.05).In sGTCS group,the FA of the ipsilateral CT,contralateral CC,ipsilateral SLF(temporal lobe)were positively correlated with the course of disease,the FA of ipsilatera CC(hippocampus)and UF were negatively correlated with the attack frequency.There was no significant correlation between FA with the onset age.In PS group,the FA of ipsilateral CT,CC and CC(hippocampus)were positively correlated with the onset age,however,there was no significant correlation with the course of disease.Conclusion:1.The PS and sGTCS patiengts with unilateral mTLE-HS had cerebral white matter damage compared with the healthy controls.2.The sGTCS patients were more extensive than PS patients in cerebral white matter damage,and the ipsilateral hemisphere were more extensive than the contralateral hemisphere,the thalamus plays an important role in sGTCS.3.The white matter with partial injury in patients with sGTCS can be repaired with the prolongation of the course of disease,ipsilatera CC(hippocampus)and UF injury in patients with high incidence in recent three years,the younger the patients with PS,the more serious some ipsilateral white matter injury is,but there was no significant correlation with the course of disease.