Intraoperative Ultrasound in Malformations of Cortical Development

Zusammenfassung

Ziel: Kortikale Malformationen (MCD) sind eine häufige Ursache medikamentenrefraktärer fokaler Epilepsien. Intraoperativ lassen sich MCD häufig schwierig vom normalen Hirngewebe abgrenzen. In dieser Studie untersuchen wir die Anwendbarkeit von intraoperativem Ultraschall (IOUS) zur Lokalisierung und Abgrenzung von MCD. Material und Methoden: Fünf Epilepsiepatienten mit mindestens einer MCD-verdächtigen Läsion wurden unter Anwendung von IOUS operiert. Die Ergebnisse des IOUS wurden mit dem präoperativen MRT und der Histopathologie verglichen. Ergebnisse: In drei Fällen fokaler kortikaler Dysplasie (FCD) Typ IIB und einem Fall periventrikulärer Heterotopien konnten die Läsionen gut im IOUS dargestellt werden, die Konfiguration der Läsionen im IOUS entsprach deren Aussehen im MRT. Dagegen konnte nur eine von zwei FCD Typ I im IOUS dargestellt werden. Schlussfolgerung: IOUS kann zur intraoperativen Darstellung von FCD IIB und periventrikulären Heterotopien hilfreich sein, die Darstellbarkeit von FCD Typ I scheint jedoch schwieriger zu sein.

Abstract

Purpose: 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. Materials and Methods: 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. Results: 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. Conclusion: 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.

Key words

intraoperative ultrasound - epilepsy - seizures - ultrasound 2D - dysplasia

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