Localizing Findings in the Secondarily Generalized Tonic-Clonic Seizures: A study with videotape analysis

Abstract

Discrimination of the extratemporal lobe epilepsy (ETLE) from temporal lobeepilepsy (TLE) in patients with medically refractory localization-related epilepsy is very important. Because o successful surgical treatment relies on exact localization of the epileptic zone. Clinical ictal semiology which was assessed during prolonged video EEG monitoring can provide important informations on the localization of the seizure onset zone. With this study, blinded to clinical details, we made o retrospective videotape analysis of 149 SGTCSs in 80 patients with 62 temporal lobe epilepsy (TLE), 18 extratemporal lobe epilepsy (ETLE). All SGTCSs were classified into two periods, namely "the antecedent seizure phase" and the "generalized tonic-clonic phase". During these periods we systemetically assessed following features : durations of the seizure phases,onset times and durations of the dystonic/tonic posture and version and time of the day at seizure occurrence. Mean duration of the antecedent seizure phase of ETLE which was occurred during nighttime was o significant shorter than that of TLE which was occurred during nighttime (p=0.0001), the duration of the antecedent seizure of ETLE was significantly shorter than that of TLE (p=0.025) and onset time of the version ofETLE was signifıcantly earlier than that of TLE (p=0.047). Our findings observed thatgeneralization occurred more rapidly in ETLE. Since surgical treatments is o therapeuticalalternative in patients with intractable seizures localization of seizure origin are the principal aim in the preoperative assessment of these patients. So, we believed that in particular duration of the antecedent seizu re phase and onset time of the version may provide additional objective information which was localizing value in patients with medically refractory localization-related epilepsy.