Usefulness of video-EEG in the paediatric emergency department.

Expert Review of Neurotherapeutics

ISSN: 1473-7175 (Print) 1744-8360 (Online) Journal homepage: http://www.tandfonline.com/loi/iern20

Usefulness of video-EEG in the paediatric emergency department Raffaele Falsaperla, Pasquale Striano, Pasquale Parisi, Riccardo Lubrano, Fahad Mahmood, Piero Pavone & Giovanna Vitaliti To cite this article: Raffaele Falsaperla, Pasquale Striano, Pasquale Parisi, Riccardo Lubrano, Fahad Mahmood, Piero Pavone & Giovanna Vitaliti (2014) Usefulness of video-EEG in the paediatric emergency department, Expert Review of Neurotherapeutics, 14:7, 769-785 To link to this article: http://dx.doi.org/10.1586/14737175.2014.923757

Published online: 11 Jun 2014.

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Usefulness of video-EEG in the paediatric emergency department Downloaded by [University of California, San Diego] at 22:08 05 November 2015

Expert Rev. Neurother. 14(7), 769–785 (2014)

Raffaele Falsaperla1, Pasquale Striano2, Pasquale Parisi3, Riccardo Lubrano4, Fahad Mahmood5, Piero Pavone1 and Giovanna Vitaliti*1 1 Pediatric Acute and Emergency Operative Unit and Department, Policlinico-Vittorio Emanuele University Hospital, University of Catania, Via Plebiscito 628, 95124 Catania, Italy 2 Muscular and Neurodegenerative Diseases Unit, G. Gaslini Institute, University of Genova, Genova, Italy 3 Child Neurology and Paediatric Sleep Centre, Chair of Pediatrics, NESMOS Department, Faculty of Medicine and Psychology, Sapienza University of Rome, Rome, Italy 4 Department of Pediatrics, Sapienza, University of Rome, Rome, Italy 5 University College London Medical School, University of London, London, UK *Author for correspondence: Tel.: +39 095 743 5451 [email protected]

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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. KEYWORDS: acute differential diagnosis • diagnostic value • emergent department • emergent video EEG • pediatric • therapy perspective

Over the past two decades, technical improvements in performing an EEG have been substantial with a shift from analog to digital machines and more recently to video-EEG systems. Despite these advances, recording a technically acceptable EEG in electrically hostile environments, such as an emergency department (ED), remains challenging especially with uncooperative patients, infants, young children and conscious impairment, as well as in the restricted environment of a busy ED with lack of timely access to an EEG [1]. The most significant of these technical challenges include high line noise (60 Hz) in the recorded signals due to high ambient noise levels, long electrode wires, and relatively high electrode impedances and interelectrode impedance differences; time needed to attach a full set of EEG electrodes and achieve low electrode-scalp impedances; availability of trained neurophysiology technicians; and limiting physical access to patients attached to electrode wires and EEG equipment [1].

10.1586/14737175.2014.923757

The different patterns of the EEG obtained from emergency patients, although often nonspecific, can be correlated with the etiology of CNS disease, such as trauma [2], vascular injury as well as anoxic-ischemic injury due to cardiorespiratory arrest [3]. For example, in postinfective encephalopathy [4,5], particularly herpes simplex encephalitis [6,7], and in nonconvulsive status epilepticus (NCS) [8–12], the EEG is a decisive diagnostic tool and thus guides therapy as well as giving valuable prognostic information. Furthermore, the EEG also contributes to characterizing the state of consciousness in cyclotrimethylenetrinitramine intoxication and metabolic encephalopathy [13,14]. Thus, the EEG has gained importance in the identification of cases with persistently reduced or altered consciousness, but with normal brain imaging, particularly in infants and patients with light-tomoderate mental retardation [2,14]. In addition, the importance of the EEG in the ED was reported in 1996 by the French Neurological

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Consensus Conference, where a list of emergency conditions requiring the use of an urgent EEG were described [15]. From that conference until now, further statements have been published on the use of an emergency EEG in other nonepileptic disorders such as migraine and minor brain injuries [16,17]. The aim of our review is to show the usefulness and diagnostic importance of a video-EEG, highlighting the predictive factors for positive and negative outcomes, when performed in a pediatric ED. Moreover, we aim to highlight through the description of our own experience the emergency use of the EEG in pediatric EDs, particularly for the differential diagnosis of status epilepticus with nonepileptic paroxysmal events. EEG in the ED: a reasonable explanation

Abundant literature from the past few decades exists characterizing the well-defined routine use of the EEG in EDs [18]. Routine use of EEGs in acute settings may advance patient care in certain neurological scenarios such as acute alteration of mental status and severe traumatic brain injury (sTBI) [19–21]. In such clinical scenarios, access to cerebral function is often hindered by an unrevealing bedside physical exam in obtund or deeply sedated subjects [22,23]. Since the initial call by Jordan, in 1995 [24], for a major monitoring system able to continuously evaluate cerebral function in critically ill patients, several studies have aimed to characterize the role of the EEG in various clinical contexts, including the ED. Emergent EEG & convulsive status epilepticus

Generalized convulsive status epilepticus (GCSE) and partial convulsive status epilepticus are neurological emergencies that carry a mortality risk of 7–39% and are associated with lifethreatening sequelae if not managed in a timely manner [25–27]. Furthermore, as outlined by DeLorenzo et al., in 1992 [28], more than 50% of reported GCSE cases resulted from various acute brain injuries. Moreover, clinical manifestations of CSE are often easily recognized when witnessed during the tonicclonic episodes. However, after controlling the overt symptoms of GCSE, NCS might predominate and result in persistent obtundation. This is evidenced by various studies reporting patients with GCSE who continued to have NCS after cessation of convulsions [29]. Furthermore, specific EEG patterns recorded after controlling convulsions were shown to be significantly correlated with prognosis [30]. Another important challenge for the ED neurology physician is the diagnosis of partial convulsive status epilepticus, defined as a pathological condition localized to a discrete area of the cerebral cortex, producing no alteration in consciousness. In this situation, EEG monitoring must diagnose subtle status epilepticus by correlating the onset and persistence of localized ictal discharges. Nonconvulsive partial status epilepticus is also recognized as an emergency situation, best approached with an urgent EEG study. Moreover, it can inform the decision to discontinue unnecessary antiepileptic drugs used to treat ‘status epilepticus’ once the EEG reveals cessation of the seizure [31]. Thus, convulsive status epilepticus is an entity highly correlated with various neurological emergencies 770

requiring prompt early management although subsequent NCS is more difficult to recognize and manage. Evaluating cerebral function via the EEG after control of clinical CSE has however led to a change in prevailing opinion as reported in recent literature regarding treatment and assessment of outcomes. Emergency EEG in autonomic status epilepticus: panayiotopoulos syndrome

In childhood, another syndrome often referred to pediatric EDs due to the onset of autonomic status epilepticus is panayiotopoulos syndrome (PnyS). It is a common benign epilepsy affecting otherwise healthy children, who present with autonomic seizures, in which nausea, retching and vomiting are particularly common and prominent. Because of the unusual ictal symptoms and lengthy manifestations, misdiagnosis is a common major problem. In the literature, diagnostic confusion has been described with encephalitis, syncope, migraine, sleep disorders or gastroenteritis [32]. In addition, its presentation could be atypical, as the case described by Ozkara et al. [33] of a young girl presenting with intractable and lengthy vomiting attacks with several hospital admissions and extensive gastroenterological workup over several years from early childhood. On all previous occasions, the diagnosis varied from psychosomatic disease, to functional dyspepsia, to cyclic vomiting syndrome. The possibility of autonomic epileptic seizures and PnyS, though likely, was not considered until the performance of an ictal EEG that confirmed diagnosis of the syndrome. Furthermore, in 2008, Tedrus et al. [34] studied clinical and EEG features of children with PnyS. They evaluated 36 children aged 2–13 years, with seizures occurring between 1 and 5 years of age. Fourteen children (38.8%) had a single seizure, while a further 14 children (38.8%) had autonomic status epilepticus. Impairment of consciousness was reported in 30 (83.3%) children, eye deviation in 10 (27.7%), other autonomic symptoms and head deviation in 9, generalization in 8, visual symptoms in 1 child, and speech arrest or hemifacial motor symptoms in 8 cases. The EEG showed occipital spikes or spike-wave complexes in 27 (75.0%) children, blocked by opening of the eyes in 8 (22.2%) cases. Nine patients (25%) also had rolandic spikes and 3 had extraoccipital spikes. Six (16.6%) patients had a normal EEG. No clinical differences were observed between patients having occipital or extraoccipital spikes. In children with mainly autonomic seizures, the spikes were predominantly occipital but blockage by opening of the eyes was a less frequent feature. However, Specchio et al. [35] in 2010 reported a review of 14 cases, describing EEG features of patients affected by PnyS. They found that interictal EEGs were characterized by spikes of variable locations that often changed with time. Ictal EEG onsets were also variable starting from wide anterior or posterior regions, usually with theta waves intermixed with small spikes and fast rhythms. Ictal vomiting and other autonomic manifestations, as well as eye deviation, did not appear to relate to any specific region of EEG activation. Thus, the authors concluded that PnyS is a multifocal autonomic epilepsy and supported the view that the clinical manifestations are likely to be Expert Rev. Neurother. 14(7), (2014)


Usefulness of video-EEG in the paediatric ED

generated by variable and widely spread epileptogenic foci, acting on a temporarily hyperexcitable central autonomic network. Video-EEG studies have also been performed in PnyS with Koutroumanidis et al. [36] describing a neurologically and developmentally normal child with infrequent seizures characterized by emetic symptoms and other autonomic phenomena with interictal spikes, satisfying the diagnostic criteria of PnyS. However, two video-EEG recordings, taken a year apart, revealed prolonged autonomic seizures and other subtle behavioral changes, suggesting that episodes of NCS in PnyS may be more frequent than appreciated. Thus although there is no specific diagnostic marker for PnyS, the EEG represents the most useful neurophysiological evidence of occipital electrical involvement. The experience of PnyS demonstrates the importance of considering this diagnosis in pediatric ED cases presenting with persistent autonomic symptoms, with prompt performance of the EEG to reduce the risk of a misdiagnosis. Emergency EEG & NCS

Non convulsive status epilepticus (NCSE) was shown to occur in more than one-third of patients with unexplained alteration of mental status [16]. However, NCSE may present a diagnostic challenge when an EEG is unavailable in the ED, which is often the case [37]. The lack of overt tonic-clonic activity and the difficulties in identifying behavioral changes, above all in infants, from baseline necessitate the presence of an EEG to confirm seizure activity. However, this can be a challenge for the emergency physician who is more used to associating tonicclonic movements with the presence of a seizure and therefore may not think of status epilepticus in patients without tonicclonic movements. Early and more recent studies done in the ED as well as the ICU have thus reported significant delays in the diagnosis of NCSE [38–40]. Furthermore, apart from the wide range of behavioral manifestations occurring in NCSE, it may also include various subtle ictal or atypical morphologies that are difficult to interpret in emergency settings [40]. The literature on EEG features in NCSE includes a spectrum of manifestations that could coexist in other entities, making distinction and consequent ictal identification more difficult. In addition, another feature of NCSE that argues for the importance of notifying a neurologist is treatment. Even when a diagnosis of NCSE can be made, treatment and its potential adverse outcomes particularly in children may present challenges to acute/ED physicians [41,42]. These issues thus justify the need for routine EEG availability as well as adopting a case management approach system that allows a remote epileptologist to review emergency EEGs recorded in acute settings and provide a report, consistent with the clinical features, where expertise for such interpretation in the ED are not available. Moreover, this highlights the need for a systematic protocol for management of these events. Emergency EEG & nonepileptic seizures

The incidence of nonepileptic seizures (NES) is increasing and a major subcategory of these patients present to EDs informahealthcare.com

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with convulsive-status epilepticus, an entity that puts patients at a high risk of iatrogenic harm, including unnecessary intravenous medications and ventilatory support for airway protection [43,44]. A strong clinical suspicion usually precedes hospital admission and observation during an attack by ED physicians is crucial [45,46]. However, the diagnosis of NES cannot be established in the ED and requires long-term inpatient EEG/video monitoring. Despite the established role of prolonged video-EEG in diagnosing NES, identification of suggestive features is still important for further diagnostic monitoring. The use of EEG during the paroxysmal episode may help in providing ED personnel with an early provisional diagnosis, which could determine further tests needed for a definitive diagnosis. Recent studies have highlighted the importance of suggestive features in raising clinical suspicion of a nonepileptic etiology during initial assessment [47,48]. Documenting a negative interictal EEG in the ED might enhance clinical suspicion and thereby preclude the need for inpatient monitoring. It is worth noting that certain types of epileptic seizures such as frontal lobe seizures may be mistakenly diagnosed as psychogenic [49]. Frontal lobe seizures are initially distinguished from nonepileptic events through various features, including suggestive clinically abnormal movements, resistance to physical examination as well as other features from the history such as resistance to antiepileptic drugs. This further signifies the importance of preliminary suggestive features, which in turn may help in increasing or decreasing the index of suspicion in patients presenting with seizure-like symptomatology. In addition, one major study reported that patients with two seizurelike events a week, who have previously shown resistance to at least two (antiepileptic drugs) and who had at least two EEGs without epileptiform anomalies, had a more than 80% chance of having a NES of psychogenic origin [50]. Thus, the presence of a negative EEG might increase the diagnostic yield of other clinical features in an acute setting where access to video-EEG is restricted. Another important differential diagnosis that should be considered in the ED is the presence of sudden nocturnal events with an affective semiology (such as sleep terror disorders, nightmares, nocturnal panic attacks) that could mimic partial seizures. Epileptic seizures with affective semiology (terrifying affective seizures), consisting of brief and sudden panic symptoms with incomplete recall associated with interictal EEG spike-wave complexes in the anterior and posterior temporal regions of either or both hemispheres, were first described in 1980 in 20 patients by Dalla Bernardina et al. [51]. Forty percent of patients had a family history of epilepsy; the prognosis was benign and the interictal EEG pattern was similar to that of benign childhood epilepsy with centrotemporal spikes. The semiology of sleep terror disorders is characterized by age of onset (less than 5 years; mean age 18 months, with a peak prevalence at 5–7 years [52]), signs of panic 2 h after falling asleep (stage IV) with crying, screams, a fearful expression, inability to recognize other people including parents (for a 771


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duration of 5–15 min), amnesia upon awakening and a slight correlation with somnambulism (about 50% of the affected children are sleep-walkers) [53]. However, there are some epileptic events that mimic these sudden nocturnal events, including autosomal dominant nocturnal frontal lobe epilepsy that is characterized by heterogeneous nocturnal seizures and, in most cases, is unsupported by EEG abnormalities. Patients often complain of nocturnal sleep discontinuity, difficulty in waking, morning tiredness or excessive daytime sleepiness. The seizures usually occur during light sleep (stage II) and are grouped into three major categories: paroxysmal arousal, nocturnal paroxysmal dystonia and nocturnal wanderings [54]. The specific epileptic phenotype of autosomal dominant nocturnal frontal lobe epilepsy is consistent with complex partial seizures (sometimes simulating a panic attack), nocturnal frontal lobe seizures and NCS [55]. The seizures are resistant to treatment and the EEG abnormalities consist of slow waves with occasional spikes located in the frontal lobe [56]. It is therefore vital that EEG and/or video-EEG recordings of paroxysmal morphemic events are considered for diagnosis, as it has been shown that a number of paroxysmal episodes assumed to be nonepileptic in nature are seizures arising from the frontal or temporal lobes [57]. EEG pattern in encephalitis

Clinical involvement of the CNS was considered an unusual manifestation of human viral infections, even if in the past decades this has become more accepted. In light of this, the performance of the EEG in patients affected by encephalitis is becoming more commonplace than in previous years. The EEG is strongly recommended in any suspected case of acute encephalitis since it may help in distinguishing focal encephalitis from generalized encephalopathy, with a deeper involvement of the CNS [58]. Furthermore, in the case of encephalopathy, the EEG usually shows diffuse, bihemispheric slow waves, such as triphasic slow waves and/or 2–3 Hz periodic lateralized epileptiform discharges of the temporal lobes, often present in the later stages [58]. Additionally, in the study by Hamid et al. on 120 EEG studies of patients affected by encephalitis, 83.3% of cases had an abnormal EEG pattern and these findings were considered a potential negative prognostic factor for human encephalitis [59]. However, in practice, the EEG does not help in differentiating the various types of encephalitis and the main benefit of the EEG is to demonstrate cerebral involvement during the early stage of the disease. Only in rare instances does the EEG show specific features that may give clues to the diagnosis. For example, in herpes simplex encephalitis, 80% of patients have typical findings in the EEG. In addition to the background slowing, there is a temporal focus showing periodic lateralized epileptiform discharges. This finding is temporary and is found during days 2–14 from the beginning of the disease, most often during days 5–10 [60]. Detection of this EEG finding often requires serial recordings. The repetition interval of these pseudoperiodic 772

complexes is from 1 to 4 s and in newborns it can be faster with a frequency of 2 Hz although localization in newborns may be other than temporal [61]. Furthermore, the EEG can be useful to demonstrate a CNS involvement also in subacute sclerosing panencephalitis, in which the EEG shows a typical generalized periodic EEG pattern repeating with intervals between 4 and 15 s and synchronized with myoclonus of the patient [58]. However, in another study on longterm outcomes of acute encephalitis in childhood, all children who developed epilepsy had pathological EEG findings during the acute phase of encephalitis [62]. In acute viral encephalitis, the EEG is thus an early and sensitive indicator of cerebral involvement and usually shows a background abnormality prior to the initial evidence of parenchymal involvement on neuroimaging. This may in some instances be helpful in the differential diagnosis of aseptic meningitis [63], often with focal abnormalities observed. Moreover, during the acute phase, the severity of EEG abnormalities does not usually correlate with the extent of the disease. However, a fast improving EEG indicates a good prognosis, while lack of improvement in the EEG recording indicates a poor prognosis [58]. Although there may be seizures in the acute phase, interictal epileptiform EEG activity is a rarity and EEG abnormalities usually subside more slowly than the clinical symptoms [58]. Emergency EEG in brain injuries

Extensive reports in the literature suggest that EEG study is a nonspecific and uninformative indicator of the presence of brain dysfunction after a mild traumatic brain injury (mTBI) [64–66]. A mTBI differs from a sTBI by the absence of loss of consciousness or the presence of loss of consciousness for a few seconds, for a better outcome on the Glasgow Coma Scale and for the little cerebral involvement evidenced by CT scans and MRI [66]. MTBI may present with symptoms similar to a postictal state due to a cellular injury secondary to disrupted axoplasmic flow, cellular oxidative stress or disrupted cytoplasmic homeostasis [66]. These biological sequelae occur in the first hours or days, without an expected EEG deterioration months or years later [66]. Firstly, in animal models during experimental head injuries, immediate EEG changes have been detected as initial epileptiform activity, described as a high-amplitude shape wave [67], low-amplitude high-frequency discharges [68,69], epileptiform discharges [70–72] or generalized high-voltage spiking [73]. This is followed in all the experimental models by a period of suppressed cortical activity, often nearly isoelectric [67–74], lasting from 10 s to several minutes and typically for 1–2 min. Following the EEG suppression, there is a period of generalized slowing, gradually improving to a normal baseline EEG over 10 min to 1 h [66]. Secondly, in contrast to the report by Liguori [75] in 1989, where there was evidence that the EEG could be correlated with the CT scan findings in mTBI patients, Osler showed that EEG study is not indicated in these Expert Rev. Neurother. 14(7), (2014)



patients and the examination is unrevealing and misleading [76]. The most common EEG patterns found after an mTBI are attenuated posterior-alpha and focal irregular slow wave activity with a preponderance of theta waves in the temporal region [77,78]; however, minor alpha asymmetry is of dubious diagnostic value because such a change frequently occurs among normal people [79], often linked to drowsiness, pain and anxiety [80]. Furthermore, within 24 h a post concussion EEG is often normal and any focal abnormality tends to disappear within 6 months to a few years [66]. In the initial months after an mTBI, it is possible to see EEG abnormalities with a normal clinical exam, especially among patients who had few or no symptoms [81]. Nevertheless, it seems that abnormal EEG does not predict clinical impairment and EEG abnormalities do not always correlate with neurological findings [66]. Therefore, these data suggest that EEG may help to assess the severity of trauma shortly after the event (from 10 min to 1 h), but it is not helpful in assessing subsequent or chronic clinical symptoms [82]. This assumption has been confirmed by Oster et al., who retrospectively analyzed 150 EEG studies on children admitted to the Children’s Hospital of the University of Saarland for mTBI, within 24 h of the concussion. They found that only 11 patients showed an abnormal nonspecific EEG [83]. Thus, the authors concluded that the routine performance of an EEG after an mTBI in children is not indicated because in most of the cases it is unrevealing, and may lead to unnecessary diagnostic procedures, while EEG study should be performed to closely monitor the onset of possible clinical complications and neurological deterioration [83]. It has also been speculated that a quantitative mTBI-derived EEG could be considered a discriminant test for the differential diagnosis of mild, moderate and severe traumatic brain injuries [84]. Nevertheless, this failed to show good accuracy when evaluated in further studies and quantitative mTBI-derived EEG panels as well as discriminants still seem to have many unresolved problems. However, there is a minor percentage (0.7–3%) of children affected by mTBI that could evolve into sTBI, with loss of consciousness, drowsiness, amnesia, prolonged headache and clinical evidence of basal or nonfrontal skull fracture that have been identified as risk factors for a negative prognosis [84]. In these patients, in whom a decrease of the Glasgow Coma Scale is observed, the performance of an urgent EEG is mandatory, both because an EEG could provide evidence of an early stage of coma as well as monitoring the depth of coma. Moreover, it has been demonstrated that in sTBI EEG correlates well with the depth of posttraumatic coma [85–92]. Despite a wild variety of abnormal EEG patterns, including increased slow activity, amplitude suppression in greater injuries, typical sleep features, epileptic spikes, periodic lateralized epileptiform discharges, and triphasic waves [65], none is pathognomonic of trauma per se. Finally, EEG gradually renormalizes in many sTBI, more quickly for generalized slowing than for focal abnormalities. informahealthcare.com

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Video-EEG monitoring

The EEG technique has improved from the use of analog to digital recording machines and more recently to video-EEG monitoring systems. This latter technique is widely used as a diagnostic and management tool in patients with seizures. In 1954, Gastaut and Bert were the first to highlight the advantages of evaluating the simultaneous behavioral and EEG features of patients’ seizures, ‘in conditions as close as possible to those of life itself’ [93]. They indicated its use in two main groups of assessment: presurgical workup and diagnostic evaluations. The diagnostic evaluation could be considered in patients with atypical seizures in whom there is a question of presence or absence of epilepsy, as well as in patients with drug-resistant epilepsy and the clarification of epilepsy syndromes [94–96]. The performance of video-EEG monitoring, in the context of a comprehensive epilepsy program, requires the involvement of a highly trained multidisciplinary team, including EEG scientists, nursing staff, epileptologists, neuropsychologists, imaging specialists and technicians, as well as expensive monitoring equipment. A number of studies have specifically examined the sensitivity and/or specificity of video-EEG for diagnosis and presurgical localization. Shneker et al. [97] retrospectively correlated the following parameters: history and examination, sleep-deprived EEG and MRI imaging abnormality with outcomes after 4 days of video-EEG monitoring, noting a high correlation of MRI abnormality (along with epileptiform features on EEG) to the eventual diagnosis of epilepsy in video-EEG monitoring. Shihabuddin et al. [98], looking at ambulatory recordings for diagnosis, emphasized this technique’s utility in those suspected of having nonepileptic events. Furthermore, Drury et al. [99] led a study on 18 elderly cases, finding that 55% of patients had diagnoses other than epilepsy. Moreover, Binnie et al. [100] evaluated the records of 181 patients who underwent video-EEG monitoring and found a diagnosis in 68% of cases. Mohan et al. [101] retrospectively studied the records of 444 patients who underwent video-EEG for diagnostic purposes (excluding those who were admitted for a presurgical evaluation) and reported that 73% successfully obtained diagnostic information. Finally, a further study on 400 consecutive patients who underwent inpatient video-EEG reported valid diagnostic information in 289 (72%), of whom 31 (11%) had psychogenic seizures [102]. However, very few published studies specifically examined the proportion of patients in whom the inpatient video-EEG monitoring resulted in a change in the preadmission diagnosis. Recently, Ghougassian et al. [103] performed a study on 91 patients who had an ictal event recorded, finding that the preadmission diagnosis was changed in 76 (83%) as a result of the video-EEG monitoring. The changes in diagnoses in our patients discussed below represented a significant change in the seizure type (i.e., partial vs generalized), in the diagnosis of epilepsy versus nonepileptic events, with the greatest category of diagnostic change being an increase in the number of patients being 773


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diagnosed as having NES. These results compared favorably with Sutula’s study [104] with a 48% change in epilepsy classification and with Binnie’s study [105] with 68% obtaining information sufficient to clarify when the use of an urgent EEG is useful for a clinical first-line diagnosis. The diagnosis of NES by video-EEG has been documented to result in a substantial reduction in a variety of direct medical costs in the 6 months after the EEG study compared with the previous 6 months: An average 84% reduction in seizurerelated medical charges, a 76% decline in diagnostic test charges, a 69% decrease in medication charges, an 80% decrease in outpatient clinic visits and a 97% decrease in ED visits [106–109]. Furthermore, this is a very important diagnostic group, as the correct diagnosis allows potentially toxic anticonvulsant drugs to be ceased and also saves potential hospital and medical resources being unnecessarily used in the mistaken belief that the patient is having uncontrolled epileptic seizures. Emergency EEG in pediatric clinical practice: a description of our experience

The EEG is a technique that has been routinely used for more than 50 years for its ability to explore the cortical electrical activity. The recent development of newer methods of anatomical and functional imaging has limited its clinical indications. Nevertheless, the EEG remains essential for assessing cerebral maturation, for determining a patient’s physiological (awakening and sleep) and pathological (comas) level of wakefulness and in epileptology. Taken together, the abovementioned literature highlights the importance of performing an EEG in an emergency setting. Nevertheless, it is still not clear for what kind of pediatric emergency diseases an EEG is indicated and the timing for performing a diagnostic EEG. In 1996, a meeting of French experts established a set of guidelines based on a review of the available literature [15]. During this meeting, authors collected the most suitable indications for performing an emergency EEG, and in particular they suggested: • An EEG should be performed in the emergency room, as soon as possible, in the following cases: – – – –

Clinical hypothesis of cerebral death; Convulsive status epilepticus; Myoclonic status epilepticus; Follow-up of patients affected by convulsive status epilepticus; – Convulsive status epilepticus before any treatment, in case of doubt on the epileptic nature of the crisis, in an already known epileptic patient; – Onset of neurosedation after a brain injury, or clinical modifications under neurosedation in case of brain injury; – Generalized or focalized relapsing convulsive seizures. • An EEG should be performed within 24 h in the following cases: 774

– Clinical semiology suggestive of NCS (vigilance alteration, mental confusion, psychiatric hallucinations); – Onset of seizures after a brain injury; – Onset of generalized epileptic crises; – Clinical signs of a focal seizure; – Clinical diagnosis of herpes simplex encephalitis. After this consensus meeting in 1996, no other international consensus with such extensive indications for emergency EEG has been published and the main recommendations for performing an emergency EEG still refers to those indicated at the French meeting. Nevertheless, the importance of an emergency EEG in the pediatric population has been highlighted by various authors. In children, the published data on the performance of an emergency EEG are limited even though they support its use. Since the French conference [15], few studies have been conducted on the predictive value of emergency EEGs. In 2004, Praline [110] et al. published a retrospective study on adult patients, analyzing 329 consecutive emergency EEGs over a 6-month period. They observed that the most frequent indications for EEG were presumption of brain death (13%), convulsive status epilepticus after treatment (12.1%) and suspicion of NCS (10.6%), and more than one-third of the requests were not in conformity with the consensus conference [15]. Therefore, the authors concluded that the contribution of the EEG is much improved by the application of the consensual criteria, remaining essential for the management of convulsive status epilepticus after treatment, to seek subtle status epilepticus or NCS. However, it was not found to be useful in emergency use after a transient loss or alteration of consciousness or a focal, nonfebrile, transient or permanent neurological deficit. In addition, as far as the use of an emergency EEG in children is concerned, Alehan et al. led a retrospective study on 56 patients (aged between 1 and 25 years), finding that among all patients who were diagnosed with epilepsy, 76% had an abnormal EEG result in the ED [111]. Later, in 2005, Kothare et al. [112] led a retrospective study on 1821 EEG tests done, with 32 EEGs done as an emergency (mean age of patients 4.5 years), of which 18 were performed in an ED, 8 as long-term bedside records and 6 emergency video-EEGs concluding that emergency EEGs and video-EEGs were useful in decision making in 94% of cases. In 2007, Praline et al. [113], in their prospective descriptive study on 16 children and 96 adults, found that the emergency EEG contributed to the diagnosis in 77.6% of cases, helping to confirm a clinical suspected diagnosis in 36% of cases and to rule it out in the remaining 64%. Recently, in 2012, Ygit et al. [114] led a study on 449 patients, among whom 36 were children under 16 years of age, finding an abnormal EEG result in 71% of patients when hospitalized, while the percentage was lower (59.5%) when the EEG was performed at discharge. Finally, in 2013, Fernandez et al. [115] retrospectively studied the predictive value of the emergency EEG on 68 children (mean age 7.3 years) and they found that 59.1% Expert Rev. Neurother. 14(7), (2014)



of children were discharged from the ED and were sent home with a diagnosis mainly based on the result of the emergency EEG. Our observational study thus has the advantage of having a greater sample size of children ever studied for the evaluation of the diagnostic value of the EEG performed in the acute and ED, and to study a relatively large group of children affected by different neurological diseases, and therefore providing input for further expanding the existing guidelines for performing an emergency EEG. Another topic to clarify is the timing of when an emergency EEG should be performed as well as the lack of evidence to support the completion of an EEG before discharge from the ED after a first seizure. The 1996 French Consensus indicated that an emergency EEG should be performed as soon as the request is done. In 1998, King et al. [116] performed a prospective descriptive study on 300 patients, among whom 59 children under 16 years of age were included. They found that the EEG performed within 24 h of the episode detected more abnormalities than the EEG performed later. Recent literature suggests reducing the timing for performing an emergency EEG up to 16 h [117]. Nevertheless, further studies should clarify how to define an emergency EEG and the timing for performing it after request. In addition, recent research is focusing their interest on establishing the diseases that are eligible for performing EEG in the acute and ED. It has been demonstrated that the earlier the EEG is performed from the onset of a seizure, the higher the possibility to diagnose ictal abnormalities [118]. Moreover, abnormalities such as postictal slowing can be transient and should be interpreted with caution in the context of the presentation and timeframe after a seizure [118]. The question however is the quantification of this earlier time. As previously discussed, the 1996 French Consensus divided the diseases requiring an emergency EEG into two groups: those in which EEG should be performed within 24 h and those as soon as possible, but still within 24 h [15]. Furthermore, in a series of 449 adults who underwent an EEG within 16 h of the initial paroxysmal event, an abnormal result was present in 71% of those admitted to the hospital and in 59.5% of those who were discharged from the ED (p = 0.19) [119]. Thus, although all published data to date suggest the emergency use of an EEG in children, this is far from established with many questions remaining. All these studies in childhood did not evaluate the immediate usefulness of the emergency EEG within the emergency visit and they also did not indicate any ideal timing for performing an emergency EEG. Thus, to our knowledge there are no data in the current literature on the optimal timing for performing an emergency EEG in childhood within the pediatric acute and emergency visit. Video-EEG at emergency room: our experience

On the diseases requiring an emergency EEG and the optimal timing for performing this investigation, we led a retrospective observational study on 100 pediatric patients (mean informahealthcare.com

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age 7.66 ± 2.43 years) to evaluate the diagnostic efficiency of video-EEG in the emergency room. This was an observational, multicenter study involving the Acute and Emergency Pediatric Department, Policlinico-VittorioEmanuele University Hospital, University of Catania; the Child Neurology and Paediatric Sleep Centre, La Sapienza University of Rome and the Muscular and Neurodegenerative Diseases Unit, G. Gaslini Institute, University of Genova, Italy. From December 2011 to December 2012, we collected data of children admitted for the onset of seizures and/or neurological signs and symptoms to the emergency rooms of the abovementioned pediatric departments (TABLE 1), where an emergency video-EEG was performed within 16 h of admission, as literature data suggest [117]. Furthermore, ruling out nonconvulsive status was considered a priority. In our experience, it was important to underline the short timing between the request of the EEG and its performance by specialized physicians. This is in accordance with the latest clinical guidelines commissioned by the National Institute for Health and Clinical Excellence (UK) suggesting that children, young people and adults requiring an EEG should have the test performed soon after it has been requested [109]. This study was designed to identify the reasons emergency physicians requested an emergency EEG in daily medical practice, to assess the diagnostic value and the therapeutic benefits that could be expected and to determine the consequences of the EEG results on subsequent patient management. Each EEG was recorded for a minimum of 30 min by using a digital EEG acquisition system. We placed 11 to 20 electrodes on each patient’s scalp according to the 10–20 Standard International System. As far as the electrodes used for video-EEG performance, for a full assembly, a precabled cap was used (Bionen, Florence, Italy) with 20 permanent electrodes, according to the 10–20 Standard International System, using a longitudinal assembly with bipolar derivation. For a reduced assembly, Ag/Au small cup electrodes were used (Bionen, Florence, Italy), positioned according to the 10–20 Standard International System, using a longitudinal assembly with bipolar derivation associated with a transversal assembly. In every case simultaneous ECGs were recorded. Responses to pain and noise were recorded when the patient had an alteration in wakefulness. The EEG interpretation was immediately communicated to the attending physician by an electroencephalographist and later a written result was sent. To provide homogeneous, complete and clear results, each EEG recorded was also interpreted by the neurophysiology technicians of the three hospitals included. Twenty-four to 48 h later, we asked the attending physician if the results of the emergency EEG modified, confirmed or ruled out the suspected clinical diagnosis and if it changed the patient’s subsequent therapeutic management. We analyzed the percentage of normal and abnormal EEG results for subgroups of neurological diseases and the 775

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Table 1. Descriptive analysis of the patients admitted to the pediatric acute and emergency room for the onset of seizures who underwent an emergency video-EEG study. Patient consecutive number

Diagnosis

Age (years)

Sex

Video-EEG at admission at emergency room

Cerebral areas involved

1

Seizures after a minor traumatic brain injury

3

Male

Multifocal anomalies

Frontal region

2


14

Female

Normal

3


3

Male

Normal

4


9

Male

Normal

5


4

Male

Normal

6


2

Male

Normal

7


6

Female

Normal

8


3

Male

Normal

9


7

Female

Normal

10


14

Male

Normal

11


9

Female

Normal

12


4

Male

Normal

13


3

Female

Normal

14


5

Male

Normal

15

Seizures after a major traumatic brain injury

11

Male

Normal

16


2

Female

Normal

17


4

Female

Normal

18


3

Female

Normal

19


3

Male

Normal

20


7

Male

Normal

21

Mycoplasma encephalitis

13

Male

Normal

22

Mycoplasma encephalitis

12

Male

Slowing down of the normal EEG activity

23

Chlamydia encephalitis

10

Male

Normal

24

Bickerstaff encephalitis

5

Male

Normal

25

Borrelia burgdorpheri encephalitis

9

Male

Diffuse background slow electrical activity

26

Meningococco encephalitis

12

Female

Normal

27


8

Male

Normal

28


7

Male


29

Herpes simplex virus encephalitis

10

Female

Normal

30

Herpes simplex virus encephalitis

11

Male


31

Miller Fisher syndrome

6

Male

Normal

32

Folate deficiency

1

Male

Generalized anomalies

Right occipital region

Whole cerebral areas




ESES: Electrical status epilepticus; NES: Nonepileptic seizure; PnyS: Panayiotopoulos syndrome; TTH: Tension-type headache.

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Table 1. Descriptive analysis of the patients admitted to the pediatric acute and emergency room for the onset of seizures who underwent an emergency video-EEG study (cont.). Patient consecutive number

Diagnosis

Age (years)

Sex



33

Folate deficiency

2

Male

Slow electrical activity


34

Cerebral tumor

5

Male

Slowing of the base rhythm

Right hemisphere

35

Cerebral tumor

7

Male

Slowing of the base rhythm

Right hemisphere

36

Cerebral stroke

6

Male

Focal spikes

Frontal region

37

Cerebral stroke

7

Female

Normal

38

Cerebral stroke

9

Female

Focal spikes

Frontal region

39

Cerebral stroke

7

Male

Focal spikes

Temporal region

40

Cerebral stroke

6

Female

Normal

41

Syncope triggering convulsion

5

Female

Normal EEG (positive tilt test)

42


14

Female

Normal

43


10

Female

Normal

44


12

Female

Normal EEG (positive tilt test)

45

Exercise-induced syncope (Wolf–Parkinson–Withe)

13

Male

Normal EEG (positive ECG and cardiologic evaluation)

46

Exercise-induced syncope (Wolf–Parkinson–Withe)

1

Male

Normal EEG (positive ECG and cardiologic evaluation)

47

Drug-resistant epilepsy

10

Female

Generalized paroxysmal activity

Diffused

48


7

Male

Slowing of the basic rhythm

Right hemisphere

49


5

Male


Frontal bihemispheric region

50


2

Male

Paroxysmal anomalies tending toward generalization

Right frontal and temporal regions

51


9

Female

Not-modulate slow basic activity

Frontal region

52


3

Male


Frontal region

53


14

Female

Generalized spikewaves activity

Left frontal region with spreading to homologous contralateral regions

54


8

Female

Focal frontal spikewaves with contralateral spreading

Bilateral frontal regions



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Diagnosis

Age (years)

Sex



55


13

Female


Bilateral frontal regions

56


17

Female


Generalized with bilateral frontal predominance

57


6

Male

ESES

Generalized spikewaves

58


11

Female

ESES


59


7

Female


Frontal region

60


10

Male

Paroxysmal anomalies tending toward generalization

Right frontal and temporal region

61


9

Male


Occipital region

62


8

Female

ESES


63


11

Male


Frontal region

64

NES

1

Male

Normal

65

NES

9

Male

Normal

66

NES

5

Male

Normal

67

NES

3

Male

Normal

68

NES

10

Female

Normal

69

NES

8

Male

Normal

70

NES

7

Male

Normal

71

NES

7

Female

Normal

72

Psychogenic paroxysmal nonepileptic event

2

Male

Normal

73


12

Male

Normal

74


13

Female

Normal

75


11

Female

Normal

76


8

Female

Normal

77


10

Female

Normal

78


8

Male

Normal

79

TTH, according to IHS

3

Male

Focal anomalies in the central-right region

Central-right hemisphere

80

Frequent episodic TTH, according to IHS

6

Female

Spike-waves on the left hemisphere

Left hemisphere


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Table 1. Descriptive analysis of the patients admitted to the pediatric acute and emergency room for the onset of seizures who underwent an emergency video-EEG study (cont.). Cerebral areas involved

Patient consecutive number

Diagnosis

Age (years)

Sex


81

Migraine without aura (IHS)

7

Male

Normal

82

Typical aura with migraine headache (IHS)

10

Male

Normal

83

Basilar-type migraine (IHS)

8

Female

Slowing of the basic rhythm

Diffused

84

Migraine with aura associated with confusional status

12

Male

Ictal right subcontinuous occipital spike-waves

Right occipital area

85

Migraine with aura associated with confusional status

14

Male

Ictal left subcontinuous occipital spike-waves

Left occipital area

86

Migraine without aura followed by confusional status

12

Female

Ictal right subcontinuous occipital spike-waves spreading to contralateral regions


87

Migraine/Alice in wonderland syndrome

10

Female

Right frontotemporal sharp and spikeswaves

Right frontotemporal area

88

Migraine/Alice in wonderland syndrome

9

Female

Left centrotemporal biphasic sharp

Left temporal region

89

Acute abdominal pain and confusional migraine

10

Male

Normal

90

PnyS

12

Male

Normal

91

PnyS

5

Female

Multifocal seizures with an occipital predominance

Occipital area

92

PnyS

11

Male

Multifocal seizures with an occipital predominance

Occipital area

93

PnyS

8

Male

Occipital right focal discharge with spreading to homologous contralateral regions


94

PnyS

1

Female

Right frontal spikewaves

Right frontal area

95

PnyS

6

Female

Left occipital spikewaves

Left occipital area

96

PnyS

3

Female

Right centrotemporal biphasic sharp

Right rolandic area

97

PnyS

3

Male

Left frontotemporal sharp and spikeswaves

Left frontal area

98

PnyS

2

Male


Left frontal area



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Diagnosis

Age (years)

Sex



99

PnyS

10

Female


Left occipital area

100

PnyS

6

Male

Right occipital spikewaves




percentage of cases in which an emergency EEG was fundamental to make diagnostic decisions on the follow-up of every patient. Performing a video-EEG within 16 h from admission, we made a diagnosis of electrical abnormalities in 47% of patients of the total number of admitted children. Video-EEGs added more diagnostic information with respect to normal EEGs in all cases affected by paroxysmal nonepileptic events. When we subsequently divided our patients into subgroups, according to the diagnosis of the disease for which these children entered our pediatric departments, we observed a different distribution in percentage of successful diagnostic EEGs according to the specific disease. Firstly, abnormalities in the EEG pattern were present only in 10% of children with seizures after an mTBI (1/20 showed multifocal anomalies); in the case of septic encephalitis, EEGs showed electrical abnormalities in 40% of cases, with a peculiar slowing of the basic electrical activity independently from the septic etiology (Mycoplasma, Borrelia burgdoferi, meningococcal and herpes simplex virus encephalitis); in the case of metabolic syndrome (affected by Miller Fisher syndrome and folate deficiency), video-EEGs showed electrical anomalies in two of the three observed cases (only in children affected by folate deficiency, intended as insufficient dietary intake of folate resulting in anemia); the two patients affected by cerebral tumors showed electrical anomalies characterized by a slowing of the basal rhythm; in the case of cerebral stroke, we found an altered electrical activity in 50% of patients, showing the presence of focal spikes; and in the case of syncope (both triggered by a convulsive episode and by exercise), videoEEG results were all normal. Video-EEGs gave positive results in all known epileptic patients affected by drugresistance epilepsy, already following anticonvulsive therapies, but with recrudescence of their disease, while the investigation was negative in all patients affected by nonepileptic events, as expected. In cases of headache and migraine, videoEEGs were abnormal in 72.7% of cases showing different abnormal patterns. Finally, in children video-EEGs showed the presence of abnormal electrical activity in all children affected by PnyS, mostly with the typical EEG pattern characterized by occipital spikes, although in some cases centrotemporal and frontal regions were exclusively involved 780

(results are shown in TABLE 2). Ultimately an emergency videoEEG was useful in decision making in 96.6% of cases. As far as the diagnostic value of emergency video-EEG results is concerned, not only positive findings but also negative results were important to make decisions on the follow-up of these patients. Firstly, in the case of seizures after minor traumatic brain injuries, the absence of EEG anomalies helps avoid unnecessary anticonvulsive treatment. Moreover, even if an emergency EEG is not diagnostic in the case of an mTBI, it is mandatory to detect evolution of the same mTBI toward an sTBI, whereby during the observation period the child may present with a loss of consciousness and a decrease in the Glasgow Coma Scale. This is important as the EEG can identify the initial phase of a comatose status and correlates with the depth of coma. Next, the pathological patterns found in the cases of acute septic encephalitis are important to evaluate the cerebral involvement of infection, to control the evolution of these patterns during hospitalization, and deciding the usefulness of anticonvulsive therapy according to the persistence of neurological signs and symptoms. In addition, the presence of focal epilepsy in the cases of cerebral stroke is important to evaluate the depth of cerebral damage caused by the same disease and the progression from the acute to the chronic phase of the event. This differentiates cases with transient abnormal electrical activity, secondary to blood reperfusion syndrome, with those of chronic cerebral involvement, with persistence of electrical anomalies due to more stable cerebral damage. Furthermore, an emergency video-EEG was positive in all cases of drug-resistant epilepsies, as expected, even if the diagnosis of the critical event, rather than the electrical activity registered during the intercritical period, better focused on the features of the same epileptic event. This allowed us to adjust the therapy according to the critical features of the ictal cerebral activity. The video-EEG was instead negative in all cases of nonepileptic events, as expected, and this finding was important because in a pediatric acute and emergency room differentiating these nonepileptic events from epileptic status helps avoid the use of anticonvulsive therapies and further clinical follow-up requiring hospitalization or imaging, including CT scans and MRI. Thus, identifying this differential diagnosis is




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fundamental to avoid improper hospiTable 2. Descriptive results found in our observational study. talizations with subsequent cost impliMain EEG alteration Disease for Percentage cations for the National Health System. admission in ED of abnormal In contrast, there are other neurological EEG (%) symptoms, such as headache, and automTBI 10 Multifocal anomalies in the frontal region nomic symptoms, such as recurrent vomiting and abdominal pain, that Septic encephalitis 40 Diffuse background slow electrical activity should be thoroughly investigated Metabolic 70 Diffused nonspecific abnormalities because they could be the first sign of syndrome an epileptic status and/or PnyS. In Cerebral tumor 100 Slowing of the basal rhythm these cases, an emergency video-EEG can distinguish all cases with abnormal Cerebral stroke 50 Presence of focal spikes cerebral activities that should undergo Syncope Nil Normal EEG further investigation from those who DRE 100 Diffused abnormalities could possibly receive simple treatment at the emergency site, without requirNil Normal EEG Paroxysmal ing any hospitalization and/or further nonepileptic events examinations. The proportion of patients with seizHeadache/migraine 72.7 Different abnormal patterns ures who visit the ED is greater during PnyS 100 Occipital spikes and centrotemporal and childhood than at any other age [119], frontal spikes (in some cases) and among them the proportion of DRE: Drug-resistant epilepsy; ED: Emergency department; mTBI: Minor trauma brain injury; patients visiting the ED for seizures is PnyS: Panayiotopoulos syndrome. higher than for other neurological emergencies. Despite the high frequency of seizures in the traumatic brain injuries, encephalitis, cerebral strokes, paroxyspediatric EDs, the use of emergency EEGs at the ED is still mal nonepileptic events, migraine, headache and PnyS. debated. Until now, the work of the French Consensus Group of 1996 is the most widespread study showing the Expert commentary & five-year view usefulness of an emergency EEG in acute and ED. Never- The importance of this paper relies on the prompt recognition theless, its indications seem to be restricted only to some of neurological diseases and differential diagnosis by the use of specific groups of neurological patients. In this regard, our an EEG in EDs in pediatric cute and emergency settings. The paper highlights the importance of performing an emer- use of this technique and the timing of its performance have gency EEG in a wider spectrum of neurological diseases, not been widely debated in the literature, with the last guidelines only involving epileptic status and/or paroxysmal nonepilep- published in 1996, in the French Meeting Consensus. This tic events but also including other neurological diseases such paper highlights the importance of emergency EEGs and videoas those involving persistently depressed consciousness after EEGs in clinical practice for the recognition of different neuroa prolonged seizure, those in whom nonconvulsive seizures logical diseases and a related correct diagnostic and therapeutic are suspected, patients with minor brain injuries, metabolic follow-up of these diseases, to evaluate the cost–benefit balance syndromes, cerebral strokes, headache and autonomic of their standard management in acute and emergency rooms. Our paper gives a topic to perform standard guidelines, definsyndromes. ing in what cases an emergency EEG should be requested, the best timing of performance of this study from the onset of Conclusion An emergency EEG has been demonstrated to be a fundamen- symptoms and to open up new epidemiological studies on the tal diagnostic tool in the pediatric acute and ED due to its cost–benefit of an emergency EEG in pediatric acute and high predictive value for neurological diseases requiring further emergency room. diagnostic investigations. This in turn helps the EEG to differentiate these disorders from other neurological diseases that Financial & competing interests disclosure could be treated at the acute and emergency room, thereby The authors have no relevant affiliations or financial involvement with avoiding improper hospitalizations. This investigation would any organization or entity with a financial interest in or financial conallow a prompt first diagnostic candidate thereby improving flict with the subject matter or materials discussed in the manuscript. the cost–benefit ratio of hospitalization for children affected by This includes employment, consultancies, honoraria, stock ownership or neurological signs and symptoms. Thus, we suggest expanding options, expert testimony, grants or patents received or pending or the use of an emergency EEG for neurological patients not royalties. No writing assistance was utilized in the production of this only affected by status epilepticus but also in other diseases presenting with neurological signs and symptoms, such as minor manuscript. informahealthcare.com

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Key issues • The different patterns of an EEG obtained from emergency patients, although often nonspecific, can be correlated with the etiology of CNS disease, such as trauma vascular injury as well as anoxic-ischemic injury due to cardiorespiratory arrest. For example, in postinfective encephalopathy, particularly herpes simplex encephalitis, and in nonconvulsive status epilepticus, the EEG is a decisive diagnostic tool and thus guides therapy as well as giving valuable prognostic information. • Abundant literature from the past few decades exists characterizing the well-defined, routine use of the EEG in emergency departments. Routine use of EEGs in acute settings may advance patient care in certain neurological scenarios, such as acute alteration of mental status and severe traumatic brain injury. In such clinical scenarios, access to cerebral function is often hindered by an unrevealing bedside physical exam in obtund or deeply sedated subjects. • The EEG technique has improved from the use of analog to digital recording machines and more recently to video-EEG monitoring


systems. This latter technique is widely used as a diagnostic and management tool in patients with seizures. • The performance of video-EEG monitoring, in the context of a comprehensive epilepsy program, requires the involvement of a highly trained multidisciplinary team, including EEG scientists, nursing staff, epileptologists, neuropsychologists, imaging specialists and technicians as well as expensive monitoring equipment. • The diagnosis of nonepileptic seizures by video-EEGs has been documented to result in a substantial reduction in a variety of direct medical costs in the 6 months after the EEG study compared with the previous 6 months: an average 84% reduction in seizure-related medical charges, a 76% decline in diagnostic test charges, a 69% decrease in medication charges, an 80% decrease in outpatient clinic visits and a 97% decrease in emergency department visits. • In 1996, a meeting of French experts established a set of guidelines based on a review of the available literature. After this consensus meeting in 1996, no other international consensus with such extensive indications for an emergency EEG has been published and the main recommendations for performing an emergency EEG still refers to those indicated at the French meeting. Nevertheless, the importance of an emergency EEG in the pediatric population has been highlighted by various authors. In children, the published data on the performance of an emergency EEG are limited even though they support its use. • Our paper highlights the importance of performing an emergency EEG in a wider spectrum of neurological diseases, not only involving epileptic status and/or paroxysmal nonepileptic events but also including other neurological diseases such as those involving persistently depressed consciousness after a prolonged seizure, those in whom nonconvulsive seizures are suspected, patients with minor brain injuries, metabolic syndromes, cerebral strokes, headache and autonomic syndromes. • An emergency EEG has been demonstrated to be a fundamental diagnostic tool in the pediatric acute and emergency department due to its high predictive value for neurological diseases requiring further diagnostic investigations. This in turn helps the EEG to differentiate these disorders from other neurological diseases that could be treated at the acute and emergency room, thereby avoiding improper hospitalizations.

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Managing paediatric death in the emergency department.

Obesity management in a Paediatric Emergency Department.

Extreme temperatures and paediatric emergency department admissions.

Paediatric femur fractures at the emergency department: accidental or not?

Blood culture diagnostic yield in a paediatric emergency department.

Management of retrieval service patients within a paediatric emergency department.

Complementary and alternative medicine use among paediatric emergency department patients.

The Usefulness of Leukosan SkinLink for Simple Facial Laceration Repair in the Emergency Department.

The design of a multicentre Canadian surveillance study of sedation safety in the paediatric emergency department.

Antibiotic prescribing in the paediatric emergency department and the impact of education.

Usefulness of Nonenhanced Computed Tomography for Diagnosing Urolithiasis without Pyuria in the Emergency Department.

Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use.

Treating and Reducing Anxiety and Pain in the Paediatric Emergency Department: The TRAPPED survey.

Reducing the incidence of oxyhaemoglobin desaturation during rapid sequence intubation in a paediatric emergency department.

Emergency in emergency department.

Unplanned reattendances at the paediatric emergency department within 72 hours: a one-year experience in KKH.

A Case of Hyperventilation Syndrome Mimicking Complex Partial Seizure: Usefulness of EEG Monitoring in Emergency Department.

Usefulness of hospital emergency department records to explore access to injury care in Nepal.

Audit of acute asthma management at the Paediatric Emergency Department at Wad Madani Children's Hospital, Sudan.

Labelling of mental illness in a paediatric emergency department and its implications for stigma reduction education.

Clinical predictors of radiographic abnormalities among infants with bronchiolitis in a paediatric emergency department.

Understanding decisions leading to nonurgent visits to the paediatric emergency department: caregivers' perspectives.

Awareness in the emergency department.

Autism in the emergency department.