A multimodal concept for invasive diagnostics and surgery based on neuronavigated voxel-based morphometric MRI...

Area of Science:

• Neurology
• Neurosurgery
• Medical Imaging

Background:

• Refractory nonlesional focal epilepsy presents diagnostic and surgical challenges.
• Accurate localization of the epileptogenic zone is crucial for effective treatment planning.
• Advanced MRI postprocessing can reveal subtle lesions not apparent on standard scans.

Purpose of the Study:

• To develop and evaluate an algorithm for integrating MRI postprocessing data into neuronavigation for epilepsy surgery.
• To assess the diagnostic yield and surgical outcomes of this ROI-guided approach in patients with apparent nonlesional epilepsy.

Main Methods:

• An algorithm was developed to implement MRI-derived regions of interest (ROIs) into a neuronavigation system.
• Stereotactic ROI-guided implantation of depth electrodes and navigated resective surgery were performed.
• Data on diagnostic yield, histology, and seizure outcomes were collected and analyzed.

Main Results:

• MRI postprocessing identified subtle lesions in 11 of 14 patients with apparently nonlesional epilepsy.
• ROI-guided EEG implantation confirmed seizure onset in 13 patients, leading to resective surgery.
• Focal cortical dysplasia was diagnosed in 64% of patients, and 57% achieved complete seizure freedom (ILAE Class 1).

Conclusions:

• The developed algorithm facilitates the integration of MRI postprocessing targets into neuronavigation systems.
• This approach enables precise, minimally invasive electrode implantation and effective navigated lesionectomy.
• Neuronavigated ROI-guided surgery is a feasible and useful strategy for treating challenging cases of apparent nonlesional epilepsy.