The clinical spectrum of malformations of cortical development.

BACKGROUND Malformations of cortical development (MCD) usually manifest in childhood with epilepsy, developmental delay and focal neurological abnormalities. OBJECTIVE To evaluate the presentation and severity of epilepsy in the different types of MCD. METHOD We evaluated the first 100 consecutive patients with a neuroimaging diagnosis of MCD. They were identified among all the high resolution magnetic resonance imaging exams performed at our service between 1997 and 2001. The causes of referral were diverse, according to the routine of the neurology outpatient clinic. After magnetic resonance imaging diagnosis of the subtype of MCD a detailed clinical assessment was performed. RESULTS There were 55 females and 45 males, with ages ranging from five months to 71 years old (mean=15.2 years). Seventy-seven patients presented with epilepsy. Sixty-one had partial epileptic syndromes, 13 secondary generalized syndromes, and in three, the type of epileptic syndrome could not be established. Epilepsy was less frequent in patients with the MCD subtypes of polymicrogyria and schizencephaly (p<0.001). Patients with schizencephaly and polymicrogyria had their seizures more easily controlled by antiepileptic drugs (p<0.001). CONCLUSION That the frequency of epilepsy is lower and seizures are more easily controlled in the setting of polymicrogyria and schizencephaly. Patients with MCD frequently present with secondary generalized epilepsy early in childhood.