Date of download: 6/27/2016 Copyright © 2016 McGraw-Hill Education. All rights reserved. Panayiotopoulos Syndrome. A 5-year-old girl with nocturnal GTCS associated with clicking noises from her mouth. She went back to sleep and then woke up with a throbbing headache. EEG shows clone-like repetitive occipital spike-wave discharges. Brain MRI was normal. The patient has normal development and been seizure free for over 2 years. Panayiotopoulos syndrome (PS) is one of the most common childhood seizure disorders. It is characterized by prolonged, predominantly autonomic symptoms with EEG that shows shifting and/or multiple foci, often with occipital predominance. Three- quarters of patients have their first seizure between the ages of 3 and 6 years with a peak at 5 years. Seizures in PS occur predominantly in sleep. Vomiting is the most common symptom. Versive seizure is seen in 60%, and progression to generalized convulsions is quite frequent. Headache may be described and is concurrent with other autonomic symptoms. Most patients will have between two and five seizures. Approximately one-third had partial status epilepticus. The interictal EEG of PS shows a normal background with high-amplitude sharp- and slow-wave complexes. These are similar in morphology to those seen in benign childhood epilepsy with centro-temporal spikes. However, in PS, there is great variability in location. Occipital localization is the most common, but all other brain regions may be involved. Moreover, the complexes frequently shift in location, this possibly being age related. Brief generalized discharges are occasionally encountered. The sharp waves or sharp- and slow-wave complexes may repeat themselves regularly and propagate, especially to frontal regions. The term “clone- like” has been used to describe this appearance. EEG abnormalities in PS are accentuated by sleep. Patients are not expected to be photosensitive. Variants of the EEG that are uncommon, but compatible, with the diagnosis include mild background abnormalities and small or inconspicuous spikes. EEG Similar patterns to the ones seen in PS occasionally occur randomly in other children. Ten percent of patients with PS may have a normal awake EEG, but abnormalities are nearly always seen in sleep EEG or a series of EEGs. Consistently normal EEGs are exceptional. None of the interictal EEG abnormalities in PS appear to determine prognosis. 6,10,11 EEG foci in most patients with PS frequently shift locations, multiply, and propagate diffusely with age rather than persistently localizing in the occipital region. The occipital EEG spikes appeared initially and then shifted to the Fp region or appeared at the same time as Fp spikes, forming an Fp-O EEG pattern resulting in secondary occipitofrontopolar synchrony. This phenomenon is an age-dependent nonspecific EEG pattern reflecting the maturational process of the brain. 12 MEG in most patients showed epileptic focus in the parieto-occipital sulcus (61.5%) or calcarine sulcus (30.8%). Despite Fp-O synchronization of spike discharges in the EEG, no frontal focus was found. 13 Legend : From: Focal Epilepsy Atlas of Pediatric EEG, 2011 From: Focal Epilepsy Atlas of Pediatric EEG, 2011