Panayiotopoulos Syndrome: An Important Electroclinical Example of Benign Childhood System Epilepsy

Abstract

Summary:As a result of the converging evidence from multiple large independent studies, Panayiotopoulos syndrome (PS) is now formally recognized as a distinct clinical entity within the spectrum of benign focal epilepsies of childhood. Clinically, PS is manifested by predominantly autonomic seizures and electrographically with multifocal interictal spikes, while the few published ictal recordings have documented onsets of variable lobar topography. These typical electroclinical features do not allow straightforward assignment to a distinctive cortical area, rendering the term "focal"-as we currently understand it-problematic. This is a critical review of the clinical and EEG features of PS, focusing on those characteristics that may shed some light on its so far elusive pathophysiology. We also explore its electroclinical similarities to other idiopathic "focal" epilepsies and its differences to symptomatic focal epilepsies that may also manifest with autonomic ictal symptoms and signs. This methodology allows the formation of a rational hypothesis on the pathophysiology of PS that seems to be emerging as a good model for the so-called "system" (nonsymptomatic) epilepsies, with potentially important taxonomic implications.

Ictal EEG patterns in epilepsy with centro-temporal spikes

“…The possible explanation of these different ways of presentation can primarilyalthough not exclusively -lie in the functional nature of BCECTS, so that seizures can have different ictal morphology and localization. This hypothesis is also reinforced by the same behavior in Panayiotopoulos syndrome and can be well explained by the theory of the so called "system epilepsy" recently advanced by Wolf in 2006 [16] and, more recently, by Koutroumanidis [17] and Capovilla et al [18]. Another interesting feature of our series of patients is that in 21 children ictal discharge changed its morphology during the seizure and that, in seven patients, the EEG showed a post-ictal slowing.…”

Origin of frontal lobe spikes in the early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome)

“…The absence of a consistent EEG topography for the high amplitude spikes seen in PS has led to speculation that this form of epilepsy might not be related to a particular onset zone, but to a general brain hyper-excitability (reviewed in Koutroumanidis, 2007). Despite this suggestion, very few detailed EEG studies have been made in these patients, and most authors used only the 10-20 map of electrodes to sample the scalp potential spikes (Ohtsu et al, 2003;Lada et al, 2003).…”

“…Despite the relatively easy recognition of clinical symptoms (Ferrie et al, 2006), the highly variable characteristics of the interictal EEG activity have prevented the determination of a consistent localization for the epileptic focus (Panayiotopoulos, 2002). Such variability has even suggested to some researchers that a generalized hyper-excitability might be present (reviewed in Koutroumanidis, 2007). This theory fails to explain why there are consistent clinical manifestations of the seizures along time in the same patient and among different subjects.…”

“…The early onset benign idiopathic occipital lobe epilepsy, presently reported as Panayiotopoulos syndrome (PS), has generated a lot of interest in recent years (Lada et al, 2003;Carabalo et al, 2007;Koutroumanidis, 2007). Despite the relatively easy recognition of clinical symptoms (Ferrie et al, 2006), the highly variable characteristics of the interictal EEG activity have prevented the determination of a consistent localization for the epileptic focus (Panayiotopoulos, 2002).…”

Early onset of cortical thinning in children with Rolandic epilepsy

“…The epileptic focus is typically located in the lower motor and/or somatosensory cortex (rolandic area) (Koutroumanidis, 2007). RE is also known as benign (rolandic) epilepsy (of childhood) with centro-temporal spikes (BECTS), which reflects both the typical spontaneous remission of seizures during adolescence and the characteristic location of the epileptiform activity on the electroencephalogram (EEG) (Loiseau and Duché, 1989).…”