The Non-linear Dynaics Analysis Of Electroencephalograms Of Interictal Epilepsy People

Objective:By comparing the difference of electroencephalograms non-linear dynamics between healthy people and patients with epilepsy, this study aims to find out the application value of the non-linear dynamic data in analysing the brain function of epileptic patients in their interictal period.Subjects and methods:Subjects: 36 epileptic patients in the interictal state , who was treated in the neurology out-patient department in the Provincial Hospital during July 2010 to April 2011 (divided into two groups: tonic-clonic seizures and complex partial seizures) and 83 healthy subjects(divided into three groups by age:the youth group 20-30 years old,middle age group 31-60, , the senectitude group 61-80) were obersved by noting down their electroencephalogram non-linear dynamics data.Methods: By using electroencephalograph,with the standard of the 10–20 electrode placement system devised by International Federation of Societies for Electroencephalography,we record the 16 leads signs of brain in the subjects when they are in three stages:eyes closed,mental arithmetic with eyes closed and eyes opened. The correlation dimension(D2) and approximate entropy (ApEn) were calculated with the help of electroencephalograms non-linear dynamics analysis software.Results:1. We took down the data of correlation dimension and approximate elltropy in the male and female, and left and right brain in three stages. It conclude that there was no statistical value of the data difference between the three stages.2. In healthy people in different age groups, compared electroencephalograms non-linear dynamics data in their eyes opened and eye closed stage , the most leads grow higher ;The correlation dimension elevated in some leads of parietal lobe,occipital lobe and temporosphenoid lobe,the approximate elltropy elevated in some leads of frontal lobe,parietal lobe,occipital lobe and temporosphenoid lobe in the stages of mental arithmetic compared with eyes closed in the three groups; correlation dimension and approximate elltropy elevated in frontal lobe in the stages of eyes opened compared with mental arithmetic,the differences were statistically significant.3. The correlation dimension had no difference between the three groups in the stages of eyes closed,mental arithmetic with eyes closed;The approximate elltropy had differences in frontal lobe and temporosphenoid lobe between youth group and old age group,in frontal lobe and occipital lobe between middle age group and old age group;And there were differences in some leads of frontal lobe,parietal lobe,occipital lobe in the stages of eyes opened between youth group and old age group.4. In complex partial seizures ,compared electroencephalograms non-linear dynamics data in their eyes opened and eye closed stage , the most leads grow higher;The correlation dimension and approximate elltropy elevated in some leads of parietal lobe,occipital lobe and temporosphenoid lobe in the stage of mental arithmetic compared with eyes closed,the differences were statistically significant.5. In tonic-clonic seizure patients, compared electroencephalograms non-linear dynamics data in their eyes opened and eye closed stage , the most leads grow higher;The correlation dimension and approximate elltropy were elevated in some leads of parietal lobe,occipital lobe and temporosphenoid lobe in the stage of mental arithmetic compared with eyes closed of tonic-clonic seizure patients,the differences were statistically significant.6. Correlation dimension of some leads of frontal lobe,parietal lobe and temporosphenoid lobe dropped in complex partial seizures compared with healthy subjects in the stage of eyes closed,and no difference in the stage of mental arithmetic;Approximate elltropy of some leads of frontal lobe,parietal lobe and temporosphenoid lobe dropped in complex partial seizures compared with healthy subjects in the stage of eyes closed,and parietal lobe and temporosphenoid lobe in the stage of mental arithmetic, the differences were statistically significant;There was no difference of correlation dimension and approximate elltropy in the three stages in the tonic-clonic seizure patients compared with heathy subjects.Conclusion: About correlation dimension and approximate elltropy there was no difference between left and right brain ,male and female ,young and old in the differert groups of heathy people. Correlation dimension and approximate elltropy increased significantly during mental tasks compared to the rest stage with eyes closed in heathy people and epilepsy.The complexity of mental functions were raised.Compared with healthy persons , the complexity declined in complex partial seizures in the stages of eyes closed and mental arithmetic with eyes closed;But in tonic-clonic seizure patients, there was no difference. Non-linear analysis methods have a certain application value in juding epileptic patients'brain function in partial state.