Abstracts

Rationale: Complete seizure remission is achieved by total corpus callosotomy (TCS) in 20 to 30 % of pediatric patients with intractable epilepsy (Iwasaki M, et al. J Neurosurg Pediatr 10:7-13, 2012). Seizure control is important for better developmental outcome in pediatric epilepsy. Here, we investigated clinical factors for seizure remission and developmental outcome after one-stage TCS. Methods: This study included 24 consecutive patients with infantile or childhood onset epilepsy, who underwent one-stage TCS for alleviation of intractable seizures with minimum of 12 months post-operative follow-up. Surgical indication of each case was determined after comprehensive evaluation of epilepsy in the pediatric department. Relationships among clinical characteristics, seizure outcome at the latest follow-up, and developmental outcome at one year of surgery were investigated. In terms of clinical characteristics, the sample means and ranges include age at epilepsy onset (16 months; range 0 - 155), age at surgery (9.5 years; range 1 - 32), duration of epilepsy (8.1 years; range 0.5 - 31), and duration of follow-up (31 months; range 12 - 64). Epilepsy began as infantile spasms in 16 of these patients. Etiologies of epilepsy were unknown in 12; tuberous sclerosis in 5; chromosomal abnormality in 3; and, head trauma, neonatal ischemia, viral encephalitis and cortical malformation in 1 each. Twenty-two patients had drop attacks and related injury as a result of seizure in their history. Developmental gain was assessed by the difference between pre-operative and one year post-operative developmental quotients. Results: Complete seizure freedom (Engel class I) was achieved in 6 (26.1%); worthwhile seizure reduction (class III) was achieved in 7 (29.2%); and, no worthwhile seizure reduction was achieved in 11 patients (45.8%) at the latest follow-up. Thirteen patients (59.1%) became free from drop attacks. Duration of epilepsy shorter than 5 years was associated with complete seizure freedom (p < 0.01, Fisher's exact test). Patients with normal MRI and unknown etiology tended to achieve seizure freedom (5 of 10 patients, p = 0.05). Developmental gain was significantly larger in patients with post-operative seizure freedom (p < 0.05, Mann-Whitney U test). Conclusions: Earlier surgical indication of TCS is associated with post-operative seizure freedom, especially in those with normal MRI and unknown etiology. Seizure control after corpus callosotomy is important for better developmental outcome.