Resection of frontal lobe epileptogenic foci identified after corpus callosotomy: long term results

To analyse the results of resective surgery in patients in whom it was possible to identify a frontal epileptogenic focus through corpus callosotomy. Data from patients suffering drug-resistant epilepsy showing persistence of disabling seizures after undergoing corpus callosotomy and subsequent treatment with frontal lobe resective surgery were prospectively reviewed. Classifications according to Engel's scale before and after each intervention were evaluated, as were the percentages of seizure reduction. Additionally, the satisfaction of family members with surgical outcomes was also assessed. Eleven patients were identified. After a median follow-up period of 7 years (IQR: 3-8 years), 63.6% of patients showed improvement of seizures according to Engel's scale, 27.2% remained unchanged and one worsened. One patient was categorised as class i, 8 as class ii, one as class iii and one as class iv. The percentage reduction in the number of seizures was over 90% in 54.5% of patients, between 50% and 90% in 36.4% and less than 50% in 9.1%. Family satisfaction was reported as good or excellent in 90.9% of cases. In addition to providing better seizure control, corpus callosotomy also appears to be a diagnostic tool allowing the identification of potential targets for resective surgery. Therefore, it should be considered upon suspicion of a frontal epileptogenic focus which could be surgically treated.