Cognitive Impairment In Adult Epileptic Patients With Interictal Discharge

ObjectiveTo explore the effects of different parameters of EEG interictal epileptic discharges on the cognitive function of adult epileptic patients,so as to provide guidance for the treatment of adult epileptic patients with low seizure frequency in clinical but frequent EEG interictal epileptic discharges.MethodsTo collect 114 patients from Fujian Medical University Affiliated Union Hospital outpatient and inpatient department from 2014 to 2018,diagnosised as nonsymptomatic epilepsy after clinical onset,EEG and MRI evaluation,of which 55 males and 59 females,with an average age of 24.68±7.74-year-old and an average course of 6.75±6.56 years.All of the 114 patients were tested with clinical memory scale、Mini-Mental state examination(MMSE)、Montreal cognitive assessment(MoCA)、Digital symbol test(DSy)、Verbal fluency test(VFT)、Digit span test(DSp)to detect their cognitive function.The long range electroencephalography was performed in all of them.Epilepsy patients were divided into groups by EEG interictal epileptic discharges parameters,including different epileptic discharge indexes,different stages of epileptic discharge,side,distribution and site.SPSS 25.0 statistical software was used to conduct independent sample T test and one-way anova for the results,and the differences in memory quotient,age scale scores and cognitive test scores between different groups were compared.Spearmen rank correlation analysis was used to evaluate the correlation between EEG epileptic discharge index and memory quotient,age scale scores,cognitive test scores and clinical attack frequency.Results1.The results of comparison of test scores among groups with different EEG parameters of interictal epileptic discharges phase showed that:(1)Compared with the <1% epileptic discharge group,the >1% epileptic discharge group in the sleep stage showed lower test scores in associative learning,recognition of meaningless graphs,and MoCA(p<0.05 or p<0.01).Compared with no epileptic discharge group,the VFT score in >1% epileptic discharge group during sleep was lower(p<0.05).There were no significant differences in memory quotient,age scale scores and cognitive test scores between the <1% discharge group and the non-epileptic discharge group.(2)Compared with the < 1% epileptic discharge group,the DSy score was lower in the > 1% epileptic discharge group during waking period(p<0.05).Compared with the non-epileptic discharge group,the scores of DSy,VFT,and DSp were decreased in the > 1% epileptic discharge group during the awake period(p<0.05 or p<0.05).There were no significant differences in memory quotient,age scale scores and cognitive test scores between the <1% discharge group and the non-epileptic discharge group.(3)Compared with the sleep stage discharge group,the DSp recitation score decreased in the sleep and awake stage discharge group(p<0.01).There was no significant difference between the non-epileptic discharge group and the sleep discharge group.(4)Compared with the left side discharge group,the scores of pointing memory,MMSE and DSp recitation score decreased in the bilateral discharge group(p<0.01).The scores of MMSE,MoCA and DSp recitation score were lower in the bilateral discharge group than the right discharge group(p<0.05 or p<0.01).There was no significant difference in the scores between the focal distribution group and the multi-focal distribution group.Compared with the group without frontal discharge,the scores of VFT and DSp reverse recitation were decreased(p<0.05 or p<0.01).There was no significant difference in the scores between the EEG group with temporal discharge and the group without temporal discharge.2.Correlation analysis of EEG epileptic discharge index with memory quotient,age scale scores,cognitive test scores and clinical attack frequency in epileptic patients:(1)There was a negative correlation between the epileptic discharge index in the sleep stage and the scores of meaningless figure recognition,MOCA and VFT(p<0.05).There was a significant negative correlation between epileptic discharge index and associative learning score(p<0.01).There was a negative correlation between the index of epileptic discharge in awake period and the score of DSp recitation(p<0.05).(2)There was a positive correlation between epileptic discharge and clinical frequency of EEG(p<0.05).There was no significant correlation between the interictal epileptic discharges index and the frequency of clinical seizures in both awake and sleep phase.Conclusions1.Interictal epileptic discharge in EEG is a potential risk factor for cognitive function in adult epileptic patients.2.Interictal epileptic discharge index > 1%,epileptic discharge in awake phase,bilateral epileptic discharge and epileptic discharge in frontal area tend to aggravate the cognitive impairment in adult epileptic patients.3.For adult epilepsy patients with few clinical seizures but frequent interictal epileptic discharge in EEG,early treatment should be required to delay cognitive impairment.