Multimodal Approach for Radical Excision of Focal Cortical Dysplasia by Combining Advanced Magnetic Resonance Imaging Data to Intraoperative Ultrasound, Electrocorticography, and Cortical Stimulation: A Preliminary Experience.
BACKGROUND AND OBJECTIVE
Type II focal cortical dysplasia is the most common malformation of cortical development associated with drug resistant epilepsy and susceptible to surgical resection. Although, at present, advanced imaging modalities are capable of detecting most cortical disorders, it is still a challenge for the surgeon to visualize them intraoperatively. The lack of direct identification between normal brain and subtle dysplastic tissue may explain the poor results in terms of being seizure-free versus other forms of epilepsy. The aim of this study is to compare magnetic resonance imaging (MRI) and intraoperative ultrasound-guided neuronavigation, along with cortical stimulation and acute electrocorticography, as a multimodal surgical approach to cortical dysplasia's tailored resection.


METHODS
Six consecutive patients with type II cortical dysplasia underwent epilepsy surgery by means of MRI/intraoperative ultrasound-guided neuronavigation. Intraoperative cortical stimulation of sensory/motor cortex was performed to localize cortical eloquent areas. Acute electrocorticography was used to identify epileptogenic tissue. These findings were correlated to real-time ultrasound imaging to establish the extent of the resection.


RESULTS
Intraoperative ultrasound depicted cortical dysplasias at a higher resolution and accuracy than MRI. Therefore it maximized the extent of the resection. Both postoperative MRIs and pathology documented the extent of the resection in all patients. Seizure-freedom was achieved in 5 cases (Engel class IA), and in 1 patient it was classified as Engel class IB. No postoperative neurological deficits were observed.


CONCLUSIONS
These results strongly suggest feasibility of ultrasound-guided resection of focal cortical dysplasia. Providing high resolution and accuracy, it allows an easy, real-time discrimination between normal and dysplastic brain.
['Tringali|Giovanni|G|', 'Bono|Beatrice|B|', 'Dones|Ivano|I|', 'Cordella|Roberto|R|', 'Didato|Giuseppe|G|', 'Villani|Flavio|F|', 'Prada|Francesco|F|']
D000293:Adolescent D000328:Adult D002675:Child, Preschool D000069279:Drug Resistant Epilepsy D004558:Electric Stimulation D000069280:Electrocorticography D005260:Female D006801:Humans D064795:Intraoperative Neurophysiological Monitoring D008279:Magnetic Resonance Imaging D008297:Male D054220:Malformations of Cortical Development D008875:Middle Aged D064847:Multimodal Imaging D018084:Ultrasonography, Interventional
Focal cortical dysplasia Intraoperative ultrasound Electrocorticography Surgical resection Neuronavigation Epilepsy surgery FCD