PURPOSE: To evaluate the importance of electrocorticographic (EcoG) monitoring and the application of different surgical approaches and predictors for postoperative outcome.MATERIALS AND METHODS: A consecutive series of 36 patients with solitary supratentorial cavernous malformations and secondary epilepsy underwent surgery conducted by our department of neurosurgery between January 2004 and January 2008.The patients were composed of 15 males and 21 females between 8 and 52 years old (mean age 27.3 years) at the time of surgery.Epilepsial history,type of epilepsy at the presentation,location,residual epileptic waveform discharges,and outcomes were evaluated.RESULTS: Histopathological examination indicates cavernoma and hippocampal sclerosis in 36.5 cases.Neuronal degeneration,glial cell proliferation,and neurofibrillary tangles were found in all resected cerebral tissue of extended lesionectomy of residual epileptic foci.Lesionectomy,anterior temporal lobe resection,anterior temporal lobe resection and cortical thermocoagulation,extended lesionectomy,extended lesionectomy and cortical thermocoagulation were performed in 4,4,1,14,and 13 patients,respectively.The residual epileptic waveform discharges were captured in 9 out of 28 patients who had additional cortical thermocoagulation.However,the frequency of epileptic waveform discharges decreased in varying degrees.Follow-up spanning four to eight years indicated 27 cases were classified under grade Ⅰ (75.00%),5 cases under grade Ⅱ (13.89%),2 cases under grade Ⅲ (5.56%),and 2 cases under grade Ⅳ (5.56%).The total effective rate was 88.89% based on the Engle standard.No significant relationships were found between epileptic history,type of epilepsy at the presentation,and location and outcomes (p>0.05).However,a significant relationship was found between the rate of residual epileptic waveform discharges and outcomes (p=0.041) according to Fisher' s exact test.Conclusion ECoG monitoring,the application of different surgical approaches,and the resection of residual epileptic foci,including neuronal degeneration,glia] cell proliferation,and neurofibrillary tangles according to immediate postoperative ECoG monitoring of cavernoma,is associated with better postoperative outcome.Postoperative residual epileptic waveform discharges are useful predictors for evaluating the outcomes.