Lesion-Constrained Electrical Source Imaging: A Novel Approach in Epilepsy Surgery for Tuberous Sclerosis Complex

Area of Science:

• Neuroscience
• Medical Imaging
• Epileptology

Background:

• Epilepsy surgery in tuberous sclerosis complex (TSC) can be challenging due to multiple lesions.
• Electrical source imaging (ESI) may offer ambiguous results in such cases.

Purpose of the Study:

• To evaluate the clinical utility of lesion-constrained electrical source imaging (lcESI) for epilepsy surgery in children with TSC.
• To compare lcESI with traditional low-resolution brain electromagnetic tomography (LORETA).

Main Methods:

• Developed a novel head model for lcESI, constraining source solutions to identified tubers.
• Ranked individual tubers based on goodness-of-fit analysis with interictal and ictal electroencephalography (EEG) data.
• Assessed overlap with surgical resection cavities and correlated findings with surgical outcomes.

Main Results:

• LORETA showed limited accuracy, with only one true positive and multiple false negatives/positives.
• lcESI of ictal EEG correctly identified seizure-related tubers in patients with good surgical outcomes (true positives).
• lcESI also correctly identified tubers outside the resection zone in patients with poor outcomes (true negatives).

Conclusions:

• Lesion-constrained electrical source imaging provides valuable complementary information for presurgical evaluation in TSC.
• Reducing the solution space in ESI may enhance the yield of source localization from low-resolution EEG data.
• Further validation of lcESI in epilepsy surgery is warranted.