Article
Epilepsy surgery of focal cortical dysplasias: the usefulness of 3D ultrasound neuronavigation
Epilepsiechirurgie bei fokalen kortikalen Dysplasien: Nutzen der 3D-Ultraschallnavigation
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Published: | May 4, 2005 |
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Outline
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Objective
Focal cortical dysplasias not rarely are the cause of pharmacoresistent epileptic seizures and are frequently difficult to detect even with sophisticated diagnostic imaging like high resolution high field MRI. In addition focal cortical dysplasias mostly are hardly delineable intraoperatively under the microscopic view. Focal cortical dysplasias constitute a common cause of pharmacoresistant epileptic seizures. Radiological Detection may be difficult even with sophisticated diagnostic imaging like high resolution high field MRI. In addition focal cortical dysplasias are intraoperatively hardly delineable under microscopic view. Aim of this study was to evaluate the efficacy of 3D Ultrasound Neuronavigation for detection and resection control in epilepsy surgery of focal cortical dysplasias.
Methods
3D Ultrasound Neuronavigation assisted microsurgery was performed in 8 patients with pharmakoresistant epilepsy due to focal cortical dyplasias. Neuronavigation was based on high resolution ultrasound datasets using the SonoWand System. This system consists of a high end ultrasound device combined with integrated neuronavigation hard- and software. This results to outstanding image quality and overcomes most of the existing problems of image interpretation and ultrasound navigation. The ultrasound probe is tracked by a passive infrared camera system for acquisition of 3-D-Ultrasound datasets. Thus beside conventional navigation based on preoperative CT or MRI datasets it is possible to navigate in intraoperative “realtime” datasets and alleviate the brainshift problem.
Results
Comparing the preoperative acquired high resolution MRI dataset to intraoperative ultrasound data we could detect a different echogenity for focal cortical dysplasias than for normal cortex. The 3D Ultrasound data could be used for intraoperative neuronavigation and the information assessed was a valuable adjunct.
Conclusions
Focal cortical dysplasias seem to have a slight different echogenity compared to normal cortical brain tissue, which is detectable by high end ultrasound systems and may be used for intraoperative delineation of the lesion. The use of SonoWand US neuronavigation system helps to determine the margins during epilepsy surgery of focal cortical dysplasias.