Functional imaging: II. Prediction of epilepsy surgery outcome

✍ Scribed by Robert C. Knowlton; Rotem A. Elgavish; Al Bartolucci; Buddhiwardhan Ojha; Nita Limdi; Jeffrey Blount; Jorge G. Burneo; Lawrence Ver Hoef; Lebron Paige; Edward Faught; Pongkiat Kankirawatana; Kristen Riley; Ruben Kuzniecky

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 85 KB
• Volume: 64
• Category: Article
• ISSN: 0364-5134
• DOI: 10.1002/ana.21419

✦ Synopsis

Abstract

Objective

To gain information on the value of magnetic source imaging (MSI), 2‐[18F]fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET), and ictal single photon emission computed tomography (SPECT) to predict seizure‐free outcome following epilepsy surgery in patients who require intracranial electroencephalography (ICEEG).

Methods

This work was part of a prospective observation study of epilepsy surgery candidates not sufficiently localized with scalp EEG and MRI. Of 160 patients enrolled 62 completed ICEEG and subsequent surgical resection. Sixty‐one percent resulted in an Engel I seizure‐free outcome at a minimum of one‐year follow‐up (mean = 3.4 years). Sensitivity, specificity, and predictive values were computed for each modality. Multivariate logistical regression was used to identify prediction of surgical outcome by imaging test.

Results

MSI sensitivity for a conclusively localized study was 55% with a positive predictive value of 78%. Eliminating non‐diagnostic MSI cases (no spikes captured during recording) yielded a corrected negative predictive value of 64%. With available comparison subgroups FDG‐PET and ictal SPECT values were similar to MSI. The OR (adjusted for epilepsy and MRI classification) for MSI prediction of seizure‐free outcome was 4.4 (p =0.01). In cases with both PET and MSI, the adjusted OR for PET was 7.1 (p <0.01) and for MSI was 6.4 (p = 0.01). In the cases with all three tests (n = 27), ictal SPECT had the highest OR of 9.1 (p = 0.05).

Interpretation

MSI, FDG‐PET, and ictal SPECT each have clinical value in predicting seizure‐free surgical outcome in epilepsy surgery candidates who typically require ICEEG. Ann Neurol 2008