Prognostic Factors in Anterior Temporal Lobectomy Patients and Predictability of Prognosis by Discriminant Analysis

Kim, Ok Jun; Kim, Won Joo; Lee, Byung In

Abstract

BACKGROUND: Anterior temporal lobectomy (ATL) is by far the most commonly performed and successfully achieved surgical treatment available for patients with medically intractable temporal lobe epilepsy. The aim of this study was to find the factors related to the surgical outcome in order to predict the prognosis of ATL in an out-patient clinic (OPD) before surgery.
METHODS
We selected 54 patients with medically refractory nonlesional temporal lobe epilepsy who were treated with ATL between 1991 and 1996 in the Yonsei Epilepsy Program and were followed up for at least 2 years. We divided the 54 patients into a favorable prognosis group (Class I-II) (FPG) and an unfavorable prognosis group (Class III-IV) (UPG) according to Engel's classification. We investigated the correlation of the clinical, neu-roimaging, and EEG findings between the two groups, and the predictability of the prognosis by discriminant analysis.
RESULTS
Of the 54 patients who had ATL, 43 were FPG and 11 were UPG. Among the various factors, febrile convul-sion, medial temporal sclerosis (MTS) in MRI and localization in scalp interictal EEG were significantly higher in FPG than in UPG (p<0.05). Encephalitis and multifocal epileptiform discharges in EEG were significantly higher in UPG (p<0.05). Age, sex, onset age, seizure duration, aura, automatism, secondary generalization, seizure frequency before surgery, family history, I.Q., neurological deficits, interictal SPECT, PET, and cerebellar atrophy in MRI were not significantly different between FPG and UPG. We were able to predict correct surgical outcomes in 18 patients with 100% predictability by discriminant analysis.
CONCLUSIONS
Among the many factors, the past history of febrile convulsion and encephalitis, MTS in MRI, and interictal EEG findings were significantly related to the post-surgical outcome. We can expect correct surgical outcome at OPD before surgery through the evaluation of these various factors.