Role of intracranial electrode EEG monitoring for localizing epileptogenic zone in epilepsy

Objective To explore the role of intracranial electrode EEG monitoring for localizing epileptogenic zone in epilepsy.Methods 20 patients with refractory temporal lobe epilepsy,whose seizure onsets were unable to be localized by MRI、routine EEG and clinical characteristic,accepted long-term intracranial electrode EEG monitoring.Bitemporal lobe subdural implanted trip electrode were used to perform the ictal and interictal EEG monitoring under the guiding of the stereotactic technique.The results routine of EEG,MRI and intracranial electrode EEG were combined.The accuracy for localization of epilepitogenic zone was evaluated based on the followed-up.Results The intracranial electrode EEG monitoring was implanted within 1～5 d.Each patient was recorded the ictal and interictal discharge and was detected clinical onsets at least twice.All patients could be localized by ictal EEG.The consistency between interical EEG and ictal EEG were observated in 15 cases,the inconsistency in 3 cases,and 2 cases were bilateral discharge in interictal.The clinical outcome showed that patients were seizure-free in 13 cases(65%),improved significantly in 3 cases(15%),improved in 3 cases(15%),unimproved in 1 case(5%)according to Engel's criteria after surgery.No significant complication was found in all patients.Conclusion The intracranial electrode EEG monitoring can localize epileptogenic zone and offer reliable evidence for epilepsy surgery.