The epileptic spectrum and EEG findings in 31 patients with a congenital bilateral perisylvian syndrome are reported from the University of Alabama at Birmingham and the CBPS Multicenter Collaborative Study Group. The syndrome was characterized by pseudobulbar palsy, cognitive deficits, polymicrogyria and seizures. Associated malformations (eg. arthrogryposis, club feet) were present in 30% patients. Seizures present in 27 (87%) began between 1 month and 14 years of age (mean, 7.9 years). Seizure patterns were varied and mainly consistent with secondary generalized epilepsy; infantile spasms occurred in 4, and partial seizures in 7 (26%). EEG abnormalities were generalized spike and wave and multifocal discharges in 7, and multifocal patterns in 10 (39%). CT and MRI showed symmetric bilateral perisylvian cortical thickening. Seizures were unresponsive to AEDs in 65%. Callosotomy in 7 with intractable epilepsy and drop attacks was partially effective; drop attacks ceased in 4. 
COMMENT. The authors and study group report a developmental syndrome characterized by congenital pseudobulbar palsy, epilepsy, mental retardation, and perisylvian polymicrogyria. Patients with drop attacks may respond to callosotomy when antiepileptic drugs are ineffective.