The Effect of Corpus Callosotomy on the Electoroencephalography in the Experimentally Induced Epileptic Rats

ABSTRACT

In order to study effect of corpus callosotomy for epileptic lesions located at sensory-motor cortex/cortices, changes in amplitude, frequency of background activity and frequency of abnormal discharges of postcallosotomy electroenencephalography(EEG) recordings were observed in the crystal penicillin induced epileptic models of rats. In control group of 10 rats, simple right(craniotomy was) done and needle electrodes were bilaterally inserted into parietal and occipital scalp, connected to EEG recording system. Experimentally induced epileptic group was obtained by instillation of 1-2 drops of crystal penicillin solution(800,000 IU/ml) at right parietal area(20 rats). Postcallosotomy group was consisted of the animals streotactically performed callosotomy with blunt ended stainless steel, sized 3 mm, width and 0.5 mm, thickness(20 rats). Preoprative and postoperative EEG recordings were obtained in each animals over 20 minates. The results were as follows; 1) Bialteral synchronous epileptic discharges were shown in experimetally induced epileptic group, which compared to control group. 2) Section of the corpus callosum caused the abolition of bilateral synchronous epileptic discharges, when compared to experimentally induced epileptic group. 3) Frequency of abnormal discharges in the contralteral hemisphere was more decreased than crystal penicillin-instillated lesion in postcallosotomy group. 4) The Background activity of postcallosotomy group was slower than control group. From the results of EEG analysis, corpus callosum might paly a important role in formation of bilateral synchronous discharges and callosotomy was seemed to be an effective method to control crystal penicillin induced epileptic rats, which had epileptic focus in sensory-motor cortex.