Functional imaging: II. Prediction of epilepsy surgery outcome.
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).


CONCLUSIONS
MSI, FDG-PET, and ictal SPECT each have clinical value in predicting seizure-free surgical outcome in epilepsy surgery candidates who typically require ICEEG.
Knowlton
Robert C
RC
UAB Epilepsy Center, Department of Neurology, University of Alabama at Birmingham, School of Medicine, Birmingham, AL 35294-0001, USA.
Elgavish
Rotem A
RA
Bartolucci
Al
A
Ojha
Buddhiwardhan
B
Limdi
Nita
N
Blount
Jeffrey
J
Burneo
Jorge G
JG
Ver Hoef
Lawrence
L
Paige
Lebron
L
Faught
Edward
E
Kankirawatana
Pongkiat
P
Riley
Kristen
K
Kuzniecky
Ruben
R
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003661:Decision Support Techniques; D004569:Electroencephalography / Q000379:methods / Q000592:standards; D004827:Epilepsy / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods* / Q000592:standards; D016896:Treatment Outcome
D019788:Fluorodeoxyglucose F18