Abstract | OBJECTIVE: To discuss the localizing methods for epileptogenic zone with intraoperative electrocorticography (ECoG) by comparing it with long-term intracranial EEG. METHODS: Twenty-two patients was enrolled, who received epilepsy surgeries consecutively in our institute since April 2005 to August 2006. All patients underwent intracranial electrode implantations with long-term video-EEG monitoring before the resective surgeries and the postoperative pathologies were all proved to be focal cortical dysplasia. The extra-operative and ECoG digital EEGs were statistically analyzed and compared with each other, including interictal epileptic discharge (IED) frequency, amplitude and their correlations with ictal discharge (ID). RESULTS: In the long-term intracranial EEG, significant difference was found between IED frequency derived from ID onset verus none-onset electrodes (Z = 12.213, P < 0.001), ROC analysis showed that IED frequency is a moderately good indicator for ID, the area under the ROC curve was 0. 758 (95% CI, 0.707-0.810). There was significant difference in IED amplitude between ID and none-ID electrodes (Z = 11.765, P < 0.001). The IED frequency was significantly lower during ECoG than during long-term extra-operative monitoring (rho = 0.518, P = 0. 014). A significant positive correlation in the IED frequency pattern was found between intra-operative ECoG and extra-operative recording when the average IED frequency was over 3 spikes /min. In ECoG, the correlation of IED with ID was similar in the 'frequent' (> or = 10 spikes/min) and 'occasional' (3-10 spikes/min) groups and very different in the 'rare' (< or = C3 spikes/min) group (rho = 0.408, P = 0.147). CONCLUSIONS: The IED from long-term EEG recording had moderate correlation in frequency and amplitude with ID position. IED frequency was usually decreased on ECoG when compared with long-term monitoring. However, ECoG could reliably reflect the IED pattern and the correlations between IED with ID in term of frequency and amplitude in the long-term EEG monitoring, when IED frequency exceeded 3 spikes/min. Under this circumstance, IED could be used for localizing the epileptogenic zone.
|
Authors | Li-Xin Cai, Yong-Jie Li, Guo-Jun Zhang, Tao Yu, Wei Du |
Journal | Zhonghua wai ke za zhi [Chinese journal of surgery]
(Zhonghua Wai Ke Za Zhi)
Vol. 45
Issue 24
Pg. 1672-5
(Dec 15 2007)
ISSN: 0529-5815 [Print] China |
PMID | 18476523
(Publication Type: Comparative Study, English Abstract, Journal Article)
|
Topics |
- Adolescent
- Adult
- Cerebral Cortex
(physiopathology)
- Child
- Electrodes, Implanted
- Electroencephalography
(methods)
- Epilepsies, Partial
(physiopathology, surgery)
- Female
- Humans
- Male
- Monitoring, Intraoperative
- Retrospective Studies
|