Abstracts

RATIONALE: A small percentage of patients with IGE do not respond to medical therapy. Generalized tonic clonic (GTC)seizures are especially debilitating and can be associated with injury. The benefit of corpus callosotomy (CC)for patients with refractory IGE has not been studied.
METHODS: Outcome data was obtained prospectively from all patients with a diagnosis of IGE who underwent CC between 1991 and 2000. All had at least 6 months follow up. Outcome was meassured according to 1)Engel[ssquote]s classification 2)percentage of patients with 50% and 80% or greater seizure reduction and 3) seizure reduction (seizure frequency at pre-operative baseline compared with post-operative seizure frequence at last follow-up), utilizing paired t-test.
RESULTS: Nine patients [seven men and three women, mean age 37.9 (range 22 to 48) and mean IQ 87.3 (range 75 to 107)] with IGE and refractory GTC seizures underwent CC. All had anterior CC and one patient later underwent completion of the CC. One patient also subsequently had a vagal nerve stimulator placed. Mean follow up time was 56.2 months, with a range of 6 to 155 months. Engel[ssquote]s class outcome is the following: Class I:1 (11%), class II: 1 (11%), class III: 4 (44%), class IV: 3 (33%). Six patients had 80% and all had 50% or greater reduction in GTC seizure frequency. (The patients who later received an VNS and had CC completion remained unchanged in class III and IV, repectively). The paired t-test showed a significant reduction of GTC seizures from 4.6 seizures per month at baseline to 0.8 seizures per month at last follow-up (p=0.0023). One patient had a complication (disconnection syndrome in patient after complete callosotomy.)
CONCLUSIONS: Corpus callosotomy can be effective in reducing seizures in patients with refractory IGE. These findings suggest that interhemispheric communication between the cerebral cortices could play an important role in the generation of seizures in IGE.