Documentation of autonomic seizures and autonomic status epilepticus with ictal EEG in Panayiotopoulos syndrome

A reappraisal of interictal EEG characteristics in self-limited epilepsy with autonomic seizures, formerly known as Panayiotopoulos syndrome or early-onset benign occipital epilepsy

PURPOSE

In the 2022 New International Classification of Epilepsy Syndromes, self-limited epilepsy with autonomic seizures (SeLEAS), formerly known as Panayiotopoulos syndrome is recognized as an electroclinical syndrome that is clinically characterized by autonomic seizures and electroencephalographically by multifocal EEG foci. EEG studies were reviewed herein and the suitability of the EEG definition to characterize SeLEAS was assessed.

METHODS AND RESULTS

The EEG findings of SeLEAS studies published to date were reviewed and typical sites of EEG foci and their evolutionary changes with age were analyzed. Although previous studies investigated the details of interictal EEG characteristics in a sufficient number of SeLEAS cases, there were few systematically analyzing cross sectional and longitudinal EEG changes except one study. Despite these limited evidence, I propose the following practical and useful EEG definition. The interictal EEG characteristics of SeLEAS are multifocal EEG foci with age-dependent predominant locations; occipital (O) at 2-5 years old, and occipital and frontopolar (synchronous and independent O and Fp spikes) at 4-7 years old and centro-parieto-temporal (CPT) at 6-10 years old. O EEG foci evolve to multifocal EEG foci with a O-Fp or CPT predominance with age and disappear by 12∼16 years old. O-Fp EEG foci may further evolve to generalized spike-wave complexes and rarely to spike-wave activated in sleep. In rare cases, the EEGs do not have epileptic EEG foci.

CONCLUSION

Interictal EEG foci in SeLAES may have different EEG patterns in terms of location and the mode of appearance depending on the age at which EEG is recorded. O-Fp EEG foci may be a specific EEG pattern indicating a diagnosis of SeLEAS.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

The 2017 International League Against Epilepsy classification has defined a three-tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self-limited focal epilepsies, comprising four syndromes: self-limited epilepsy with centrotemporal spikes, self-limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic-atonic seizures, Lennox-Gastaut syndrome, developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep, hemiconvulsion-hemiplegia-epilepsy syndrome, and febrile infection-related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

Panayiotopoulos syndrome: Unusual clinical manifestations

PURPOSE

We retrospectively analyzed the electroclinical features, treatment, and outcome of patients with Panayiotopoulos syndrome (PS) who presented with unusual clinical manifestations.

METHOD

A retrospective, descriptive, multicenter study was conducted evaluating 44 patients with PS who had seizures with an unusual semiology. Data from patients with PS seen at eight Argentine centers between April 2000 and April 2019 were collected.

RESULTS

Twelve patients (29.2%) had ictal syncope or syncope-like epileptic seizures. Three children (7.3%) had recurrent episodes of vomiting. Four patients (9.7%) presented with urinary incontinence associated with autonomic signs and consciousness impairment. One child had hiccups with autonomic manifestations followed by eye deviation. One boy had episodes of laughter with autonomic symptoms followed by loss of consciousness. Six patients (14.6%) had hyperthermia without acute febrile illness with autonomic symptoms as the first manifestation. Six others (14.6%) had focal motor seizures characterized by eye and head deviation in four and eyelid blinking in two. Four patients (9.7%) had ictal headache as the initial manifestation followed by nausea and vomiting. Two children (4.8%) had their first seizure while asleep associated with cardiorespiratory arrest. Two children (4.8%) had oral automatisms, such as sucking and chewing. In two children (4.8%) coughing was the initial manifestation followed by emetic symptoms. One patient (2.3%) had vertigo with a sensation of fear, with eye deviation and unresponsiveness. One child started with continuous spikes and waves during slow sleep, behavior disturbances, and emetic symptoms.

CONCLUSION

In this study, evidence of the existence of unusual clinical cases of PS with typical EEG patterns was found. Outcome was excellent.

Bidirectional relationships of sleep and epilepsy in adults with epilepsy

This targeted review addresses the best accepted and most intriguing recent observations on the complex relationships between sleep and epilepsy. Ten to 15% of all epilepsies are sleep-related. Included in these is sleep-related hypermotor epilepsy, renamed from nocturnal frontal lobe epilepsy by a 2016 consensus conference since 30% of cases are extra-frontal, seizures are related to sleep rather than clock time, and the predominant semiology is hypermotor. Stereo-EEG is providing crucial insights into network activation in sleep-related epilepsies and definition of the epileptogenic zone. Pathologic high-frequency oscillations, a promising biomarker for identifying the epileptogenic zone, are most frequent in NREM sleep, lowest in wakefulness and REM sleep, similar to interictal epileptiform discharges (IEDs). Most sleep-related seizures are followed by awakening or arousal and IEDs cause arousals and increase after arousals, likely contributing to sleep/wake complaints. Sleep/wake disorders are 2-3 times more common in adults with epilepsy than the general population; these comorbidities are associated with poorer quality of life and may impact seizure control. Treatment of sleep apnea reduces seizures in many cases. An emerging area of research is in circadian biology and epilepsy. Over 90% of people with epilepsy have seizures with circadian periodicity, in part related to sleep itself, and the majority of SUDEP cases occur in sleep. Recognizing these bidirectional relationships is important for patient and caregiver education and counseling and optimizing epilepsy outcomes.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: A European Academy of Neurology, European Sleep Research Society and International League against Epilepsy-Europe consensus review

BACKGROUND

Some epilepsy syndromes (sleep-related epilepsies [SRE]) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life.

PURPOSES

To define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology (EAN), the European Sleep Research Society (ESRS) and the International League against Epilepsy (ILAE) Europe. The framework of the document entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For literature search a step-wise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: despite a low quality of evidence, recommendations on anamnestic evaluation, tools for capturing the event at home or in the laboratory are provided for specific SRE. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizures control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. We provide advice that could be of help for standardising and improving the diagnostic approach of specific SRE. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: an EAN, ESRS and ILAE-Europe consensus review

BACKGROUND AND PURPOSE

Some epilepsy syndromes (sleep-related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Neurocognitive and behavioural profile in Panayiotopoulos syndrome

AIM

To determine neurocognitive performance and behavioural problems in children with Panayiotopoulos syndrome.

METHOD

All 18 children (10 females, 8 males; mean age 4y 7mo; SD 1y 10mo) diagnosed with Panayiotopoulos syndrome at the Kempenhaeghe Epilepsy Center in the Netherlands between 2010 and 2017 were analysed retrospectively. All underwent a neuropsychological/behavioural assessment, an academic assessment, and a 24-hour electroencephalogram.

RESULTS

Mean full-scale IQ (93.5; range 76-123; p=0.04) and performance IQ (93.2; range 76-126; p=0.04) were within the normal range, although significantly lower compared to the normative mean. Verbal IQ (96.3; range 76-118) and processing speed (96.1; range 74-114) were not significantly lower. Simple auditory/visual reaction times, visual attention, visual-motor integration, and verbal memory were significantly lower compared to normative values. On average, patients with Panayiotopoulos syndrome were 8 months behind in arithmetic speed and 11 months behind in reading speed for the number of months in school. Behavioural questionnaires revealed significantly higher scores on reported internalizing behavioural problems.

INTERPRETATION

Children with Panayiotopoulos syndrome demonstrated diffuse cognitive dysfunction in full-scale IQ, performance IQ, visual attention, visual-motor integration, and verbal memory. A high incidence of internalizing behavioural problems was reported. This strongly suggests neuropsychological and behavioural comorbidity in children with Panayiotopoulos syndrome.

WHAT THIS PAPER ADDS

Children with Panayiotopoulos syndrome are at risk for cognitive deficits in various cognitive domains. Children with Panayiotopoulos syndrome are also prone to internalizing behavioural problems. Mild-to-severe academic underachievement was present in more than half of the children with Panayiotopoulos syndrome.

Misdiagnosis and pitfalls in Panayiotopoulos syndrome

Panayiotopoulos syndrome (PS) is a frequent (6% among children of 1-15 years) and benign epileptic syndrome, characterized by predominantly autonomic symptoms (emesis, pallor, flushing, cyanosis, mydriasis/miosis, cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility) associated with simple motor focal seizures, which can be followed by secondary generalization. Panayiotopoulos syndrome can be extremely insidious, because it can mimic several condition, such as gastroenteritis, gastroesophageal reflux disease, encephalitis, syncope, migraine, sleep disorders, or even metabolic diseases. This peculiar pleiotropism should be kept in mind by child neurologists and pediatricians and general practitioners, because a wrong diagnosis may lead to inappropriate interventions. The consequences are high morbidity, costly mismanagement, and stress for children and their parents. The availability of electroencephalography (EEG) recording in pediatric Emergency Departments might be useful for a prompt and not-cost-consuming diagnosis. On the other hand, it is important to be aware of the possible, multifaceted, clinical presentations of PS and its clinical, radiological, and neurophysiological features in order to improve both recognition and management.

Ictal nausea and vomiting - Is it left or right?

PURPOSE

Ictal nausea/vomiting has been linked to the non-dominant hemisphere and has been considered a lateralizing sign. However, small case series and single cases have reported seizure localisation in the dominant hemisphere. Here we aimed to determine the seizure localisation and lateralization in cases with ictal nausea/retching/vomiting to test the hypothesis that these signs are of lateralizing value.

METHODS

We searched two large tertiary epilepsy-center video-EEG databases (period: 1980-2017) for reports on ictal nausea/retching/vomiting and retrieved ictal EEG seizure location, lateralization and clinical symptoms.

RESULTS

We identified 13 patients with focal epilepsy and video-EEG-documented ictal nausea (n = 2), nausea and retching (n = 3), retching followed by vomiting (n = 5) or only vomiting (n = 3). Aetiology was genetic (n = 1), structural/metabolic (n = 7) or of unclear origin (n = 5). While in 12/13 patients epileptic discharges were temporal, a single case was parietal. A left-sided seizure origin was more frequent than a right-sided origin (62 vs. 38%). Assuming a left-sided language dominance in the single left-handed patient and in those two patients with unclear handedness (based on the known distribution of hemispheric speech-dominance), the distribution of ictal nausea/retching/vomiting to the dominant vs. non-dominant hemisphere was not significantly different from a random distribution (8 vs. 5, p = 0.581).

CONCLUSION

Ictal nausea/retching/vomiting are most frequently of temporal origin. In contrast to previous studies, our ictal video-EEG data suggests that these signs have no lateralizing value. Thus, video-EEG should be performed and while this clinical sign points to a temporal seizure origin, it does not determine its lateralization.

The pathophysiology of cardiac dysfunction in epilepsy

Alterations in cardiac electrophysiology are an established consequence of long-standing drug resistant epilepsy. Patients with chronic epilepsy display abnormalities in both sinoatrial node pacemaker current as well as ventricular repolarizing current that places them at a greater risk of developing life-threatening cardiac arrhythmias. The development of cardiac arrhythmias secondary to drug resistant epilepsy is believed to be a key mechanism underlying the phenomenon of Sudden Unexpected Death in EPilepsy (SUDEP). Though an increasing amount of studies examining both animal models and human patients have provided evidence that chronic epilepsy can detrimentally affect cardiac function, the underlying pathophysiology remains unclear. Recent work has shown the expression of several key cardiac ion channels to be altered in animal models of genetic and acquired epilepsies. This has led to the currently held paradigm that cardiac ion channel expression may be secondarily altered as a consequence of seizure activity-resulting in electrophysiological cardiac dysfunction. Furthermore, cortical autonomic dysfunction - resulting from seizure activity-has also been suggested to play a role, whereby seizure activity may indirectly influence cardiac function via altering centrally-mediated autonomic output to the heart. In this review, we discuss various cardiac dysrhythmias associated with seizure events-including tachycardia, bradycardia and QT prolongation, both ictally and inter-ictally, as well as the role of the autonomic nervous system. We further discuss key ion channels expressed in both the heart and the brain that have been shown to be altered in epilepsy and may be responsible for the development of cardiac dysrhythmias secondary to chronic epilepsy.

Panayiotopoulos syndrome: a case series from Turkey

The aim of the study was to evaluate the demographic, clinical, and EEG characteristics of patients with Panayiotopoulos syndrome (PS) and the course of their illness. Thirty-eight patients followed up with a diagnosis of PS between January 2011 and December 2013 were evaluated. We found high rates of personal history of febrile convulsions, breath-holding spells, and family history of febrile convulsions, afebrile convulsion/epilepsy, migraine, and breath-holding spells. Seizures started before the age of eight in 87% of the patients, and the mean age at seizure onset was 4.6 years. Seizures were sleep-related in 81.5%, and autonomic status was seen in a third of the patients. The number of seizures was between 2 and 10 in 66% of the patients. The most common symptoms were ictus emeticus, eye/head deviation, and altered consciousness. Rolandic features were seen in 26% of the patients, and visual symptoms in 5%. Multifocal epileptiform discharges on EEG were identified in 84% of the patients. Two or more antiepileptic drugs were required in only 13% of the patients. Evolution to electrical status epilepticus in sleep and Gastaut-type epilepsy were seen in patients with more than ten seizures. The high rates of febrile convulsions, afebrile convulsions/epilepsy, migraine, and breath-holding spells in the patients and families suggest the importance of genetic factors and, perhaps, a common pathogenesis. However, the high rates of febrile convulsions and breath-holding spells in patients can be related to a misdiagnosis because of the similar symptoms. Despite its disturbing symptoms, PS is a benign epileptic syndrome requiring multiple antiepileptic drug use only in a small proportion of patients.

Usefulness of video-EEG in the paediatric emergency department

Over the past two decades the EEG has technically improved from the use of analog to digital machines and more recently to video-EEG systems. Despite these advances, recording a technically acceptable EEG in an electrically hostile environment such as the emergency department (ED) remains a challenge, particularly with infants or young children. In 1996, a meeting of French experts established a set of guidelines for performing an EEG in the ED based on a review of the available literature. The authors highlighted the most suitable indications for an emergency EEG including clinical suspicion of cerebral death, convulsive and myoclonic status epilepticus, focal or generalized relapsing convulsive seizures as well as follow-up of known convulsive patients. They further recommended emergency EEG in the presence of doubt regarding the epileptic nature of the presentation as well as during the initiation or modification of sedation following brain injury. Subsequently, proposals for expanding the use of EEG in emergency patients have been advocated including trauma, vascular and anoxic-ischemic injury due to cardiorespiratory arrest, postinfective encephalopathy and nonconvulsive status epilepticus. The aim of this review is to show the diagnostic importance of video-EEG, as well as highlighting the predictive prognostic factors for positive and negative outcomes, when utilized in the pediatric ED for seizures as well as other neurological presentations.

Ictal priapism as an autonomic manifestation of Panayiotopoulos syndrome

Panayiotopoulos syndrome is an idiopathic epilepsy syndrome presenting with a large variety of autonomic symptoms. The mechanism of autonomic symptoms is still not well understood. A neurologically normal 13-month-old boy presented on 2 occasions with complex partial status epilepticus that included significant ictal priapism. Inpatient brain magnetic resonance imaging (MRI) scan showed restricted diffusion-weighted imaging within his left temporal lobe and electroencephalograms (EEGs) left temporal slowing only. An outpatient EEG 6 months later showed abundant multifocal, predominantly posterior, as well as irregular generalized spike-and-slow-wave discharges on normal background consistent with the diagnosis of Panayiotopoulos syndrome. Ictal priapism is a previously undescribed phenomenon that is consistent with parasympathetic manifestations noted in this young boy. Acute postictal MRI and EEG findings suggest that this undeniably fascinating seizure semiological sign may be localized to the left temporal region.

Occipital lobe seizures and epilepsies

Occipital lobe epilepsies (OLEs) manifest with occipital seizures from an epileptic focus within the occipital lobes. Ictal clinical symptoms are mainly visual and oculomotor. Elementary visual hallucinations are common and characteristic. Postictal headache occurs in more than half of patients (epilepsy-migraine sequence). Electroencephalography (EEG) is of significant diagnostic value, but certain limitations should be recognized. Occipital spikes and/or occipital paroxysms either spontaneous or photically induced are the main interictal EEG abnormalities in idiopathic OLE. However, occipital epileptiform abnormalities may also occur without clinical relationship to seizures particularly in children. In cryptogenic/symptomatic OLE, unilateral posterior EEG slowing is more common than occipital spikes. In neurosurgical series of symptomatic OLE, interictal EEG abnormalities are rarely strictly occipital. The most common localization is in the posterior temporal regions and less than one-fifth show occipital spikes. In photosensitive OLE, intermittent photic stimulation elicits (1) spikes/polyspikes confined in the occipital regions or (2) generalized spikes/polyspikes with posterior emphasis. In ictal EEG, a well-localized unifocal rhythmic ictal discharge during occipital seizures is infrequent. A bioccipital field spread to the temporal regions is common. Frequency, severity, and response to treatment vary considerably from good to intractable and progressive mainly depending on underlying causes.

Autonomic epileptic seizures, autonomic effects of seizures, and SUDEP

Many generalized tonic-clonic seizures are accompanied by profound autonomic changes. However, autonomic seizures and autonomic status epilepticus can also be seen with specific electroclinical syndromes (Panayiotopoulos syndrome), etiologies, and localizations. Such autonomic symptoms may impact cardiorespiratory function. While it is likely that several factors contribute to SUDEP, further study of both ictal respiratory and cardiac changes and underlying neuroanatomical mechanisms involved in autonomic seizure semiology are likely to provide important data to improve our understanding of the pathophysiology of this devastating condition. This paper will review the association between autonomic symptoms and epileptic seizures and will highlight the work of three young investigators. Drs. Lisa Bateman and Brian Moseley will review their work on cardiorespiratory effects of recorded seizures and how this assists in our understanding of SUDEP. Dr. John Millichap will review autonomic seizures and autonomic dysfunctions related to childhood epilepsy and will discuss the importance of expanded research efforts in this field.

Benign childhood focal epilepsies

The idiopathic focal epilepsies comprise a group of syndromes characterized by focal-onset seizures for which there is no detectable structural brain abnormality and for which there is a proposed functional mechanism for the epilepsy and electroencephalography (EEG) abnormalities. This group includes benign rolandic epilepsy (BRE), benign epilepsy with occipital paroxysms (both early onset and late-onset types), idiopathic photosensitive occipital lobe epilepsy, and some less well-defined syndromes. The limits of the early onset idiopathic occipital epilepsy syndrome are not clear, and perhaps this entity represents part of a larger syndrome group of "autonomic" age-related epilepsies. The term "idiopathic" implies absence of a structural brain lesion and a genetic propensity to seizures. The term "benign" implies that the epileptic seizures are easily treated or require no treatment, show remission without sequelae with ultimate and definitive remission before adulthood, do not have severe or exceedingly disturbing seizures, and have no associated serious intellectual or behavioral disturbances. It may be that a syndrome is benign only when it can be recognized early with reasonable certainty, thereby avoiding unnecessary investigations, overtreatment, and lifestyle restrictions. Although BRE has such characteristic clinical and EEG features to make early recognition possible, this is less constantly so in the other focal idiopathic epilepsy syndromes, where the term "benign" may be inappropriate. Mild and selective neuropsychological impairment may occur even in those with typical syndromes but it is unclear whether such selective deficits outlast the active phase of epilepsy. Sometimes the clinical course may be complicated by obvious cognitive and language impairments. In such cases, the term benign is obviously inappropriate, even when seizures are rare. In most patients with the typical focal idiopathic epilepsy syndromes, medication is not necessary.

Electroencephalographic criteria for nonconvulsive status epilepticus: synopsis and comprehensive survey

There have been many attempts at defining the electroencephalography (EEG) characteristics of nonconvulsive status epilepticus (NCSE) without a universally accepted definition. This lack of consensus arises because the EEG expression of NCSE does not exist in isolation, but reflects status epilepticus under the variety of pathologic conditions that occur with age, cerebral development, encephalopathy, and epilepsy syndrome. Current NCSE definitions include "boundary conditions," in which electroencephalographic seizure activity occurs without apparent clinical seizures. Furthermore, what appears to one interpreter as status epilepticus, is not to another reader, reflecting the "art" of EEG interpretation. Seizures and epilepsy syndromes have undergone an evolution that has moved beyond a classification of focal or generalized conditions into a syndromic approach. It seems appropriate to make similar changes in the EEG analysis of the syndromes of NCSE. In effect, the literature on epilepsy classification has progressed to incorporate the different NCSE types with clinical descriptions, but the specific EEG evidence for these types is found largely in individual reports, and often by description only. NCSE classification of EEG patterns should derive from the aggregate of published EEG patterns in the respective clinical subtype, supported by an analysis of these EEG studies. The analysis that follows presents clinical descriptions and EEG patterns of NCSE in the neonatal period, infancy, childhood, adulthood, and late adulthood from a syndromic perspective based on age, encephalopathy, cerebral development, etiology, and syndrome. Proceeding from the proposed classification of status epilepticus syndromes in "Status epilepticus: its clinical features and treatment in children and adults" (published in 1994 by Cambridge University Press, New York), we have performed a systematic search for reports presenting EEG patterns of NCSE using the online medical search engine PubMed for 22 different search strategies. EEG patterns were reviewed by two board-certified epileptologists who reached consensus regarding presence of NCSE. From a total of 4,328 search results, 123 cases with corresponding EEG patterns could be allocated to underlying epilepsy syndromes. Typical characteristic, prominent electrographic patterns, and sequential arrangements are elucidated for the different NCSE syndromes. This compendium of patterns by NCSE syndrome classification with illustration of EEGs, and delineation of electroencephalographic features helps define the characteristics and semiologic borderlines among the types of NCSE.

Disengagement and inhibition of visual-spatial attention are differently impaired in children with rolandic epilepsy and Panayiotopoulos syndrome

We assessed voluntary orientation and reorientation of visuospatial attention in 313 healthy 6- to 22-year-old participants, 30 children suffering from benign epilepsy with centrotemporal spikes (BECTS) and 13 children with Panayiotopoulos syndrome (PS). The developmental section highlights the late development of reorienting skills. Only children with BECTS-R showed a strong tendency toward a rightward bias in attentional orientation. Additionally, a unilateral deficit of disengagement characterizes the patients with BECTS-R and comorbid ADHD. Right rolandic spikes seem to aggravate subclinical reorienting difficulties. Finally, children with PS failed to diffuse inhibition, except in the nearest area outside the attentional focus. This deficit could be attributed to the typical occipital-to-frontal spreading of the spikes in PS. By showing distinct attentional deficiencies according to the epileptic syndrome and the epileptic focus lateralization in BECTS, the results provide new evidence for alterations of attentional mechanisms by interictal epileptic activity, which probably contribute to learning difficulties.

Signal change in hippocampus and current source of spikes in Panayiotopoulos syndrome

A 4-year-old girl with Panayiotopoulos syndrome presented with a history of 4 prolonged autonomic seizures. The clinical features of her seizures included, in order of occurrence, blank staring, pallor, vomiting, hemi-clonic movement on the right side, and unresponsiveness. A brain magnetic resonance imaging (MRI) showed a slightly high T₂ signal in the left hippocampus. Interictal electoencephalogram revealed spikes in the occipital area of the left hemisphere. We analyzed the current-source distribution of the spikes to examine the relationship between the current source and the high T₂ signal. The current source of the occipital spikes was not only distributed in the occipital area of both cerebral hemispheres, but also extended to the posterior temporal area of the left hemisphere. These findings suggest that the left temporal lobe may be one of the hyperexcitable areas and form part of the epileptogenic area in this patient. We hypothesized that the high T₂ signal in the left hippocampus of our patient may not have been an incidental lesion, but instead may be related to the underlying electroclinical diagnosis of Panayiotopoulos syndrome, and particularly seizure. This notion is important because an abnormal T₂ signal in the hippocampus may represent an acute stage of hippocampal injury, although there is no previous report of hippocampal pathology in Panayiotopoulos syndrome. Therefore, long-term observation and serial follow-up MRIs may be needed to confirm the clinical significance of the T₂ signal change in the hippocampus of this patient.

"Electro-clinical syndromes" with onset in paediatric age: the highlights of the clinical-EEG, genetic and therapeutic advances

The genetic causes underlying epilepsy remain largely unknown, and the impact of available genetic data on the nosology of epilepsy is still limited. Thus, at present, classification of epileptic disorders should be mainly based on electroclinical features. Electro-clinical syndrome is a term used to identify a group of clinical entities showing a cluster of electro-clinical characteristics, with signs and symptoms that together define a distinctive, recognizable, clinical disorder. These often become the focus of treatment trials as well as of genetic, neuropsychological, and neuroimaging investigations. They are distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis which, in turn, often has implications for treatment, management, and prognosis. Each electro-clinical syndrome can be classified according to age at onset, cognitive and developmental antecedents and consequences, motor and sensory examinations, EEG features, provoking or triggering factors, and patterns of seizure occurrence with respect to sleep. Therefore, according to the age at onset, here we review the more frequently observed paediatric electro-clinical syndrome from their clinical-EEG, genetic and therapeutic point of views.