Abstracts

In order to assess the role of various diagnostic modalities, to identify surgical prognostic factors and concordances with presurgical evaluations, and to characterize the clinical features of frontal lobe epilepsy (FLE). We studied 71 FLE patients who underwent epilepsy surgery and were followed up more than two years. Diagnoses were established by standard presurgical evaluation. Thirty-eight of the 71 became seizure-free after surgery, and another 25 patients a favorable outcome. Clinical manifestations could be categorized into six types; initial focal motor (nine patients), initial versive seizure (15), frontal lobe complex partial seizure (14), complex partial seizure mimicking temporal lobe epilepsy (18), initial tonic elevation of arms (11), and sudden 2GTCS (4). The diagnostic accuracies of interictal EEG, ictal EEG, MRI, PET, and ictal SPECT were 28.9%, 60.5%, 47.4%, 36.4%, and 33.3% in the seizure free patients respectively. These were 21.2%, 57.6%, 24.2%, 28.6%, and 22.7% in non-seizure-free patients respectively. No significant relationship was found between the diagnostic accuracy of these modalities and surgical outcome except MRI (p=0.038). The concordance of two or more modalities was significantly observed in seizure free patients (P=0.027). Among other clinical characteristics (age at surgery, seizure frequency, sex, presence of 2GTCS, presence of possible causes, and side of surgery), only the side of surgery was a significant prognostic factors (The left side had poorer outcome.). No definite relationship was found between the location of intracranial ictal onset zone and clinical semiology. Though various diagnostic methods can be useful to diagnose FLE, only MRI can predict the surgical outcome. Concordance between presurgical evaluation modalities indicates a better surgical outcome.