A literature review showed that patients with atonic seizures and/or drop attacks who underwent corpus callosotomy (CC) were significantly more likely to achieve a greater than 50% reduction in seizure frequency compared with those who underwent vagus nerve stimulation (VNS). Adverse events were more common with VNS but they were typically mild. The most common complication of CC was disconnection syndrome. A direct study comparing both techniques is needed.
Rolston JD, Englot DJ, Wang DD, Garcia PA, Chang EF. Corpus callosotomy versus vagus nerve stimulation for atonic seizures and drop attacks: a systematic review. Epilepsy Behav. 2015;51:13-17.