Discordant clinical and neuroradiological features of congenital bilateral perisylvian syndrome in monozygotic female twins.

We here report a case of monozygotic female twins, only one of whom had congenital bilateral perisylvian syndrome (CBPS). The affected girl had all of the essential and some additional diagnostic criteria according to Kuzniecky et al. [1993]; her twin sister was completely normal both clinically and neuroradiologically. This observation may contribute towards our understanding of the etiopathogenetic mechanisms of cortical dysplasia in CBPS: fetal brain ischemia or hypoxia in only one twin seems to be a reasonable explanation in this particular case.