title: Ictal EEG modifications in temporal lobe epilepsy.
abstract: Temporal lobe epilepsy is the most common type of epilepsy in adults with medically intractable, localisation-related epilepsy, amenable to surgery. Together with clinical and neuroimaging data, presurgical ictal scalp-EEG findings are often sufficient to define the epileptogenic zone. It is widely believed that ictal scalp-EEG findings in temporal lobe epilepsy are represented by 5-9-Hz lateralised rhythmic theta activity or 2-5-Hz lateralised rhythmic delta activity. On the basis of experimental models and experience with intra-cerebral EEG recordings, the pattern of low-voltage fast activity is considered to be the electrophysiological hallmark of the epileptogenic zone. We reviewed the ictal scalp-EEG data relating to 111 seizures in 47 patients with temporal lobe epilepsy who underwent video-EEG recordings during presurgical work-up. We found that 35 patients (74.4%) showed flattening, low-voltage fast activity or fast activity as the initial EEG pattern. When visible, the rhythmic delta or theta activity followed the fast activity. Low-voltage fast activity, flattening or fast activity occurs in the majority of patients with temporal lobe epilepsy and represents the main ictal EEG pattern. Low-voltage fast activity (or similar) is also identifiable as the initial ictal EEG pattern in scalp-EEG recordings.
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan, Neurology Unit, Department of Neuroscience, University of Pisa, Pisa, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Pelliccia
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mai
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Stefano
authors.initials: S
authors.lastname: Francione
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gozzo
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Ivana
authors.initials: I
authors.lastname: Sartori
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Lino
authors.initials: L
authors.lastname: Nobili
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lo Russo
authors.affiliation: Neurology Unit, Department of Neuroscience, University of Pisa, Pisa, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pizzanelli
authors.affiliation: "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan.
authors.forename: Laura
authors.initials: L
authors.lastname: Tassi
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003700:Delta Rhythm / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D013826:Theta Rhythm / Q000502:physiology*; D016896:Treatment Outcome; D014741:Video Recording / Q000379:methods; D055815:Young Adult
keywords: epilepsy surgery; epileptogenic zone; ictal scalp-EEG; low-voltage fast activity; temporal lobe epilepsy; video-EEG recording