Surgical outcome of corpus callosotomy in patients with drop attacks

Purpose: We examined presurgical factors that independently influence surgical outcome after corpus callosotomy. For adequate measurement of the surgical outcome, we analyzed seizure outcome of drop attacks, postoperative overall daily function, and family satisfaction. Methods: At least 2 years after callosotomy (mean, 40.0 months), we retrospectively investigated 52 patients with drop attacks. As presurgical factors, we analyzed the age at surgery, age at seizure onset, age at drop attack onset, sex, hemiparesis, severe mental retardation, EEG abnormality, MRI abnormality, and extent of callosal section (total or partial callosotomy). Stepwise logistic regression was used for analysis. Results: Satisfactory outcome (seizure cessation or >90% seizure reduction) was achieved in 85% of patients with drop attacks, 32% of those with generalized tonic seizures, and 31% of those with generalized tonic-clonic seizures. The families assessed the overall daily function as improved in 62% of patients, unchanged in 23%, and impaired in 15%. Family satisfaction with callosotomy was achieved in 83% of patients (definitely satisfied, 39%, somewhat satisfied, 44%). Total callosotomy is independently predictive of satisfactory reduction of drop attacks (p = 0.013). A younger age is independently predictive of improvement of overall daily function (impaired and improved: p = 0.004) and family satisfaction (unsatisfied and somewhat satisfied, p = 0.018; unsatisfied and definitely satisfied, p = 0.0006). Conclusions: In the present study, we found that total callosotomy is more effective for treatment of drop attacks than partial callosotomy and that children receive more benefit than adults after callosotomy.