Epileptic features of patients with unilateral and bilateral schizencephaly

The extent of cortical maldevelopment might correlate with the severity of the clinical manifestation, such as cognitive delay or motor dysfunction. The objective of this study was to investigate the clinical features of epilepsy in patients with unilateral and bilateral schizencephaly. We studied 44 consecutive patients with schizencephaly diagnosed by magnetic resonance imaging (MRI). The epileptic features were analyzed in detail: frequency of epilepsy, median age at onset of epilepsy, semiology of seizures, characteristic features of electroencephalographic (EEG) abnormalities, epileptic syndromes, and antiepileptic drug treatment. We also verified the presence of motor disabilities. Data were analyzed according to the presence of unilateral or bilateral clefts and to the presence of open-lip versus closed-lip schizencephaly. We used the chi-square test and Fisher exact test for statistical analysis. Twenty-four patients had a unilateral cleft (group 1) and 20 patients had bilateral clefts (group 2). Ages ranged from 1 to 37 years (mean 10.6 years). Epilepsy was present in 15 (63%) patients in group 1 and in 11 (55%) patients of group 2; a history of status epilepticus occurred in 13% of group 1 and in 27% in group 2; and a history of clusters of seizures occurred in 40% of group 1 and in 45% of group 2. Eight (53%) patients in group 1 and 6 (54%) patients in group 2 were in monotherapy. Ten (67%) patients in group 1 and 7 (64%) patients in group 2 had seizures controlled with antiepileptic drugs. The frequency of EEG abnormalities was similar between groups (75% and 85%, groups 1 and 2, respectively). Statistical analysis showed no difference between the two groups in the variables mentioned above. However, motor disability was significantly more frequent and more severe in group 2. Regarding the type of schizencephaly (open lip versus closed lip), there was no difference in the frequency of patients with epilepsy, and severe motor deficit was more frequently found in bilateral and open-lip schizencephaly. The extent of the cortical maldevelopment in patients with schizencephaly does not correlate with the severity of the clinical and EEG features of epilepsy, unlike the cognitive and motor manifestations. In addition, the type of schizencephaly (open lip versus closed lip) does not correlate with the presence of epilepsy or seizure control, unlike motor deficit.