Cleft size and type are associated with development of epilepsy and poor seizure control in patients with schizencephaly

Abstract

Purpose: To investigate the relationship between the anatomical features of schizencephaly and characteristics of epilepsy.

Methods: We retrospectively evaluated patients diagnosed with schizencephaly using brain magnetic resonance imaging. Seizure outcomes were evaluated as drug-resistant epilepsy and frequent seizures (more than once a month) during the previous year. Development of epilepsy, seizure outcomes, and clinical variables were compared according to the anatomical features of schizencephaly, such as cleft type, size, bilaterality, presence of cortical dysplasia, and temporal lobe involvement.

Results: Of the 76 patients with schizencephaly-related epilepsy, 28 (36.8%) had open lip clefts, and 13 (17.1%) had bilateral clefts. The development of epilepsy was related to a larger cleft size and the presence of cortical dysplasia. The patients with medium-to-large clefts were younger at seizure onset than those with small clefts (9.7±7.8 vs. 20.8±10.4 years). Among the 64 patients whose outcomes were evaluated, 31 (48.4%) had drug-resistant epilepsy, and 21 (32.8%) met our definition of frequent seizures. In the univariate analysis, open lip, larger clefts, and the presence of cortical dysplasia were associated with poor seizure outcomes. Even after adjustment for covariates, open lip clefts were significantly related to drug-resistant epilepsy (odds ratio=13.036, P=0.001) and frequent seizures (odds ratio=7.682, P=0.008).

Conclusion: Open lip clefts were associated with poor seizure outcomes. Further, a larger cleft was related to an earlier development of epilepsy. The anatomical features of schizencephaly should be considered in the treatment of epilepsy.

Keywords: Cortical dysplasia; Epilepsy; Malformation of cortical development; Schizencephaly.