Clinical and electrophysiological features of frontal lobe epilepsies

Frontal lobe epilepy is the second most common epilepsy among refractory epilepsies following temporal lob epilepsy. Semiologic and electrophysiologic characterisation of frontal lobe seizures is difficult; since seizures are short, commonly accompanied by muscle artefacts. Additionally; because of the large volume of frontal lobe and rapid spread of discharges, scalp EEG can not reflect ictal discharges properly. Because of these difficulties, surgical outcomes are not as good as temporal lobe epilepsies. In this study we investigated semiologic, interictal, ictal and postictal EEG characteristics; the imaging data of FLE patients and the possible contribution of these data to localisation and lateralisation of seizures. We have evaluated 146 seizures, belonging to 36 patients (17 lesional, 19 nonlesional). There were 110 focal motor or nonmotor seizures, 18 bilateral tonic clonic seizures and 18 subclinic seizures. There were 16 patients with aura. The most common semiologic feature was hypermotor movements. Among interictal EEG's 30.5% included focal anomalies. Among ictal EEG's 66.4% were nonlocalizing or lateralizing, 17.8% were lateralising and 15,7% were localizing. The most common ictal pattern was rythmic theta activity (20.5%). In 4 patients, who had non localizing or lateralizing EEG, the postictal EEG was informative. The localizing value of PET has been found low. Diagnosing of FLE is difficult due to semiologic, electrophysiologic and imaging features. Studies involving FLE patients will contribute to diagnosis and subsequently treatment of epilepsy.