Study About Power Spectral Entropy And Its Application In EEG In Epileptic Rats

Objective: To investigate the application of the power spectral entropy(PSE) in experimental epileptic rats induced by penicillin,and to elucidate the possible value in detecting seizure .Methods : Acute chemical models were made by using microinjection in right hippocampus of rats with penicillin. Electronencephalography(EEG) were investigated by way of receiving continuous electronencephalographic monitoring by depth electrodes in Sprague-Dawley(SD) rats. 24 SD rats were divided into 4 groups randomly with each one having 6 rats and named as following:Normal Group (A):Only be implanted in the right hippocampus with depth electrode.Control Group(B):After microinjecting with physiological saline in the right hippocampus,then depth electrode was implanted.Single electrode Group (C):After being induced to seizure chemically with penicillin,one depth electrode was implanted in the epileptogenic zone.Multiple electrodes Group (D):After being induced to seizure chemically with penicillin,three depth electrodes were respectively implanted in the epileptogenic zone(a), 1.5mm mutually being apart from the epileptogenic zone(b) and the left hippocampus corresponding to the right(c).All groups of rats'behavior changes were evaluated at 2h,3h,4h according to Racine grade,and 30 minutes EEG was recorded before injecting penicillin,then EEG was recorded after injecting penicillin until seizure was end.The power of main frequencies and SPE were recorded in different part of the brain mentioned as above ,and then statistical comparations were carried out.Results: 1.Comparisons in behavior:1.1 The tonic-clonic seizure was the major presentations according to Racine grade except for group A and B.1.2Times of seizure had no significant difference in different time of observation(P>0.05),2.Comparisons in EEG and PSE:2.1The power of main frequencies of EEG in group C and D had significent difference during the ictal period compared with other periods(p<0.05).But there was no significant difference between the interical period and the pre-ictal period(P>0.05).2.2The result showed that the PSE in group C and D had dropped sharply during the ictal period and began to drop during the the pre-ictal period.2.3Comparing to the power of main frequencies of EEG and PSE in different sites(a,b,c ) of group D,we found the power of main frequencies of EEG had no difference in the different sites of brain(P>0.05),but PSE had changed apparently in a compared with b and c(P<0.05).Conclusions: 1.Power spectral entropy would be an useful way to forecast seizure .2.The inhibitory barrier breakthrough in seizure would be the possible mechanism by way of dectecting PSE in experimental epileptic rats.