Advanced intraoperative ultrasound (ioUS) techniques in focal cortical dysplasia (FCD) surgery: a preliminary experience on a case series

Abstract Introduction : Focal Cortical Dysplasia (FCD) represents a broad spectrum of histopathological entities that cause drug-resistant epilepsy. Surgery has been shown to be the treatment of choice, but incomplete resection represents the leading cause of seizure persistence. Preliminary experiences with intraoperative ultrasound (ioUS) have proven its potential in defining and characterizing the lesion. In this study we analyzed the feasibility of advanced ultrasound techniques such as sono-elastography (SE) and contrast enhancement ultrasound (CEUS) in a small cohort of patients with FCD. Material and methods : We retrospectively reviewed all clinical records and images of patients with drug resistant epilepsy who underwent at least one advanced sonographic technique (SE and/or CEUS) during ioUS guided surgery between November 2014 and October 2017. We excluded from our analysis all patients with lesions other than FCD or those who had FCD associated with other pathological entities. Results : Four patients with type IIb FCD in the right frontal lobe were evaluated. All of them underwent SE, which highlighted heterogeneous stiffness in the dysplastic foci, also multiple areas of higher consistency were detected in all patients. Three patients evaluated with CEUS had visible enhancement in the FCD. Neither SE nor CEUS were better than ioUS in the identification of lesion boundaries. In the three patients who underwent both SE and CEUS we found no correspondence between stiffer areas and enhancement in the dysplastic areas. Conclusion : Ourpreliminary report confirms the feasibility of SE and CEUS in FCD surgery and describes the imaging findings in this category of patients. Studies on larger cohorts of patients are warranted to better clarify the role of these advanced intraoperative ultrasound techniques in patients with FCD.