Abstracts

Nocturnal frontal lobe epilepsy (NFLE) is characterized by brief nocturnal motor seizures, with arousals from sleep, and may include hyperkinetic movements with tonic or dystonic features. Nocturnal hyperkinetic epilepsy can originate from frontal or temporal lobes. In NFLE, ictal EEG activity often shows beta or theta activity in frontal areas, but at times may be difficult to localize. We analyzed pattern of spread of ictal EEG activity in children with NFLE after a frontal onset, to correlate with clinical semiology of seizures., Nine children (6 boys, 3 girls, 5-18 years of age, mean 10.8 years) with NFLE were identified at Children[apos]s Hospital, Boston from semiology of seizures and ictal EEG onset. Seizure semiology of all patients was characterized by nocturnal brief stereotypical hyperkinetic movements, often with grunting and choking sounds. No obvious structural abnormalities were seen on MRI. Prolonged continuous EEG studies were performed on all patients. Ictal EEG recordings during typical nocturnal seizures were analyzed by board-certified electroencephalographers for pattern of onset and spread of ictal activity., Ictal EEG pattern was characterized by abrupt onset of beta or irregular theta activity in frontal areas (bifrontal 7, right frontal 2), and 2-10 seconds after ictal EEG onset, semirhythmic 3-6 Hz activity was seen in temporal lobes in 8 of the 9 patients, while no spread in one. Out of the 8 with temporal spread, 6 were to right temporal area, one was to bilateral temporal (left greater than right), another was either to bilateral or right temporal. Temporal spread was seen in all seizures in 5 patients, while was seen only at times in 3 patients (20%, 33%and 50% of seizures, respectively). Temporal spread was seen surrounding the time of onset of hyperkinetic movements in 5 children (This was seen at -5 to +7 seconds to onset of hyperkinetic movements for all seizures. Mean duration from temporal spread to onset of hyperkinetic movements for each child ranged from -2.4 to 3.5 seconds). In 2 children, temporal spread preceded the hyperkinetic movements by up to 22-38 seconds (mean11.9 and 17.1 seconds respectively), and in one child temporal spread followed the onset by up to 22 seconds (mean 9.2 seconds)., Our findings show that hyperkinetic movements in NFLE are often seen with temporal lobe involvement following frontal electrographic onset. Thus, from our data, temporal lobe involvement may be necessary in generation of the observed hyperkinetic movements in NFLE. Notably, temporal ictal activity can be the most prominent EEG finding, and may lead to a false impression of temporal onset in patients with NFLE. The predominance of initial spread to right temporal area is of interest, and may need further investigation.,