Intraoperative Ultrasound in Malformations of Cortical Development

Abstract

Malformations of cortical development (MCD) are a common cause of medically refractory focal epilepsy. However, the intraoperative definition of MCD can be challenging. In this study we assess the feasibility of intraoperative ultrasound (IOUS) for the intraoperative localization of MCD. Five epilepsy patients with at least one suspected lesion of MCD were operated with the aid of IOUS. IOUS was compared to preoperative MRI and histopathology. In three cases of focal cortical dysplasia (FCD) type IIB and one case of periventricular heterotopia, the lesions could be delineated well on IOUS and the configuration of the lesion corresponded to the appearance on MRI. However, only one of two FCD type I lesions could be detected on IOUS. IOUS can be helpful in defining FCD IIB as well as periventricular heterotopia intraoperatively, but this seems to be more difficult in FCD type I.