Predictive value of MRI-identified mesial temporal sclerosis for surgical outcome in temporal lobe epilepsy: an intent-to-treat analysis.
OBJECTIVE
Magnetic resonance imaging (MRI) accurately identifies mesial temporal sclerosis (MTS), but prediction of successful surgical outcome ranges from 62% to 96% in published studies. Prior investigations only used patients who had received anterior temporal lobectomy (ATL), potentially overestimating the predictive value of MRI-identified MTS (MRI-MTS).


METHODS
The authors performed an intent-to-treat analysis of 90 consecutive patients assessed for possible ATL, including 13 who did not undergo ATL because of inconclusive intracranial ictal EEG. Four (31%) of these 13 patients had unilateral mesial temporal abnormalities on their MRIs.


RESULTS
The positive predictive value of MRI-MTS for seizure cessation decreased from 0.69 to 0.63 after adjustment for these additional false positive results. Four previous studies had revealed a positive predictive value of 0.75 (0.72 after similar adjustment).


CONCLUSIONS
The authors conclude that the predictive value of MRI-MTS for outcome from ATL may be overestimated by small retrospective studies of highly selected postoperative patients.
Gilliam
F
F
Washington University Epilepsy Center, St. Louis, Missouri 63110-1093, USA.
Faught
E
E
Martin
R
R
Bowling
S
S
Bilir
E
E
Thomas
J
J
Morawetz
R
R
Kuzniecky
R
R
D000293:Adolescent; D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis* / Q000473:pathology; D002648:Child; D015331:Cohort Studies; D004569:Electroencephalography / Q000706:statistics & numerical data; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D005189:False Positive Reactions; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012598:Sclerosis / Q000175:diagnosis; D013702:Temporal Lobe / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome