Alertness Function Impairment And Correlative Factors In Patients With Temporal Lobe Epilepsy: A FMRI Study

Objective: There’s growing evidence that epilepsy activity in patients with temporal lobe epilepsy(TLE)is not a single source,often involves a wide range of brain networks.Moreover,temporal lobe epilepsy focal lesions are not limited to the temporal lobe,still remain with the parietal lobe,the frontal lobe,cerebellum,thalamus,and the limbic system in other regions of the brain function change,lead to cognitive impairment,such as memory,attention,vigilance,execution,etc.The present study aimed to research the alertness function changes and analyze the factors of affecting alertness function for patients in temporal lobe epilepsy with the functional magnetic resonance imaging(fMRI).Methods: A total of forty-four TLE patients and thirty-two healthy controls participated were recruited in this study.Rest-station functional magnetic resonance imaging(fMRI)and attention network test(ANT)was used to assessed the alertness of all participants.The altertness-related network were compared among left temporal lobe epilepsy(lTLE),right temporal lobe epilepsy(rTLE)and healthy controls.Connectivity results were extracted fromTLE patients dorsolateral prefrontal cortex converted into Z value.The multifactor linear regression were used to analyze the factors of affecting alertness networks for patients with temporal lobe epilepsy.Result: 1.The alertness-related network extracted from the patients with temporal lobe epilepsy were similar to the healthy controls,patients with TLE exhibited a decreased functional connectivity(FC)value.Compared with control group,patients with right TLE exhibited a increased FC value in the right middle temporal gyrus,right temporal pole,left superior frontal gyrus,left inferior temporal gyrus,and decreased FC in the bilateral cuneus,left middle temporal gyrus,left praecuneus,Cerebellar functional connectivity.In addition,a increased FC value in the left middle temporal gyrus,left interior superior frontal gyrus in patients with left TLE,and decreased FC in the bilateral hippocampus,right Middle Occipital Gyrus,right parietal lobe,right antiunion.Compared with right TLE,left TLE patients exhibited a decreased FC value in left hippocampus.2.Compared to the healthy controls,The reaction times of intrinsic alertness(IA)(661.44±73.23,t=3.198,P=0.002)and phasic alertness(PA)(628.71±79.55,t=3.995,P=0.000)performances of TLE patients was significantly longer than healthy controls,the total score of alerness of TLE group was shorten(t=-2.983,P=0.004),All of effective differences have the remarkable statistics significance.3.Multiple factor linear regression analysis shows that the factors related to the alertness networks of patients with temporal lobe epilepsy included seizure type(t=2.254,P=0.030)and EEG epileptiform(t=2.158,P=0.037).Conclusions: 1.Our findings show that the functional connectivity of alertness-related network has impaired in patients with temporal lobe epilepsy.2.Both of the right TLE and left TLE has the positive and negative regulation of brain regions that lack of regulation,suggesting the brain function based of the alertness-related network damage in patients with TLE。3.The left hippocampus shows greater impairment in patients with left TLE4.The intrinsic alertness and phasic alertness and alertness effect performances of TLE patients are impaired.5.The influencing factors of alertness dysfunction in TLE patients include seizure type and EEG epileptiform discharge.