Discordant electroencephalogram epileptiform activity and hemispherectomy in children with refractory epilepsy and encephaloclastic lesions: a case series.

This is a case series of six children with unilateral cerebral palsy and hemispheric encephaloclastic lesions who were evaluated for epilepsy surgery. Seizure onset was in the neonatal period in three children, at 17 months in two, and at 5 years in one. Their ictal and interictal electroencephalogram (EEG) abnormalities showed paradoxical lateralization to the incorrect/'normal' hemisphere or showed bilateral abnormalities. After cautious discussion regarding the discordant electroclinical profile and implications for outcome, they proceeded to a functional hemispherectomy (between ages 4-11y) with good outcomes (at 1-10y follow-up). Their clinical details, EEG findings, electrocorticography, neuroimaging, and histology are reported. Possible surgical candidacy should be evaluated early in children with refractory epilepsy, even those with complex profiles and discordant data from the different investigations. Contralateral or bilateral EEG abnormalities should not preclude consideration of hemispherectomy in children with refractory epilepsy, hemiparesis, and uniclastic lesions.

Paediatric new-onset seizure clinic in Australia: Experience and lessons learnt.

AIM: A new-onset seizure clinic (NOSC) was established at our hospital in 2011, with the aim to provide accurate diagnosis and appropriate management to children with new-onset seizures or seizure mimics. METHODS: We report on the data analysis of the first 200 children seen in NOSC. A paediatric neurologist or paediatric/neurology trainee under supervision of a neurologist reviewed all the children. A detailed history and clinical examination were undertaken. Electroencephalogram (EEGs) were undertaken prior to clinic review in most emergency departments. Children were classified as 'epilepsy positive' (EP+) or 'epilepsy negative' (EP-) after the first consultation. RESULTS: Of 200 patients, 109 were classified as EP+: generalised epilepsy in 57 of 109, focal in 36, childhood seizure susceptibility syndrome in 26 and epileptic encephalopathy in 5. EEG was available in 192: in 117, it was abnormal - 23 with background abnormalities and 109 with epileptiform activity. Of the 109 patients, 80 were commenced on anti-epileptic drugs (AEDs): 12 were able to come off medication after seizure-free period, 61 were controlled on AEDs and 7 were refractory. Children were followed up for 12-48 months. None of the children had diagnosis revised on follow-up. CONCLUSIONS: This is the first Australian study to report on a large cohort of children from a NOSC. An EEG and a paediatric neurologist assessment is a good combination to enable diagnostic accuracy: In the first 200 patients seen, there were no revisions of the initial diagnosis on follow-up.

Inter-rater reliability of amplitude-integrated EEG for the detection of neonatal seizures.

BACKGROUND: Amplitude-integrated electroencephalogram (aEEG) is being used increasingly for seizure detection in neonates. However, data regarding inter-rater reliability among neonatologists for the use of aEEG for the detection of neonatal seizures is lacking. METHODS: Term and late-preterm infants at risk of seizures were monitored simultaneously with 24-h video-electroencephalography (vEEG) and aEEG. vEEG was interpreted by an experienced neurologist. Five neonatologists with experience in aEEG interpretation from four different neonatal units interpreted aEEG recordings independently. The Brennan and Prediger kappa coefficient and Intra-class Correlation Coefficients (ICC) were used to assess inter-rater reliability between the neonatologists. RESULTS: Thirty-five infants at risk of seizure with gestational age at birth 35-42 weeks were recruited for the study after informed parental consent. vEEG detected seizures in seven infants with a total of 169 individual seizure episodes. Neonatologists detected seizures in 10 to 15 infants on aEEG. The sensitivities for the detection of individual seizures by neonatologists ranged from 18% to 38%. The inter-rater reliability for detection of: individual seizure was "fair" (kappa = 0.37; 95% CI: 0.32-0.42), infant with seizure was "moderate" (kappa = 0.60; 95% CI: 0.44-0.75), duration of individual seizure (ICC: 0.22; 95% CI: 0.18-0.28) and total duration of seizures in an infant (ICC: 0.46; 95% CI: 0.30-0.63) was "poor". The neonatologists missed 77-90% of the duration of seizures. CONCLUSION: The inter-rater reliability of aEEG for the detection of neonatal seizures was suboptimal. Even when interpreted by experienced and trained clinicians, seizure detection with aEEG has limitations and can miss large number and duration of seizures.

Intraoperative neurophysiology monitoring in scoliosis surgery in children.

OBJECTIVE: Intraoperative neurophysiology monitoring (INM) is thought to reduce the risk of postoperative neurological deficits in children undergoing scoliosis and spine deformity surgery. INM is being used increasingly despite conflicting opinions, varied results, non-standard alarm criteria and concern regarding cost effectiveness. In this paper we present our experience with INM in scoliosis and spine deformation surgery in children, propose alert criteria and preferred anaesthetics in clinical practice. METHODS: We retrospectively analysed our experience with INM in 56 children who had 61 scoliosis and spine deformity surgeries. RESULTS: INM was successfully undertaken with transcranial electrical motor evoked potentials (TcMEP) and somatosensory evoked potentials. There were no injuries due to INM. Four children had 5 alerts during 4 surgeries. A postoperative deficit was seen in one child only. No new postoperative deficits were seen in any child who did not have an alert during INM. Total intravenous anaesthesia was better for INM compared to inhalational anaesthetics. CONCLUSIONS: INM is useful in scoliosis surgery; it is likely to mitigate the risk of new deficits following surgery. We recommend alert criteria for TcMEPs that include multiple facets - amplitude, stimulus paradigm, morphology. We recommend propofol and remifentanil, in preference to sevoflurane and remifentanil for anaesthesia during INM. SIGNIFICANCE: Our study adds to the literature supporting the role of INM in scoliosis surgery in children. We provide guidelines for alarm criteria in clinical practice and recommend the use of total intravenous anaesthesia as the preferred anaesthetic option.

Amplitude Integrated Electroencephalography Compared With Conventional Video EEG for Neonatal Seizure Detection: A Diagnostic Accuracy Study.

This diagnostic accuracy study compared the accuracy of seizure detection by amplitude-integrated electroencephalography with the criterion standard conventional video EEG in term and near-term infants at risk of seizures. Simultaneous recording of amplitude-integrated EEG (2-channel amplitude-integrated EEG with raw trace) and video EEG was done for 24 hours for each infant. Amplitude-integrated EEG was interpreted by a neonatologist; video EEG was interpreted by a neurologist independently. Thirty-five infants were included in the analysis. In the 7 infants with seizures on video EEG, there were 169 seizure episodes on video EEG, of which only 57 were identified by amplitude-integrated EEG. Amplitude-integrated EEG had a sensitivity of 33.7% for individual seizure detection. Amplitude-integrated EEG had an 86% sensitivity for detection of babies with seizures; however, it was nonspecific, in that 50% of infants with seizures detected by amplitude-integrated EEG did not have true seizures by video EEG. In conclusion, our study suggests that amplitude-integrated EEG is a poor screening tool for neonatal seizures.

Seizure outcomes in children with epilepsy after resective brain surgery.

PURPOSE: To assess the role of resective brain surgery in childhood epilepsy. METHODOLOGY: We retrospectively analysed the seizure outcomes in 55 children with epilepsy who had resective brain surgery between 1997 and 2012, at our centre. The children were 1.5-18 years at the time of surgery; their seizure onset was between 0.2 andto 15 years of age. 48 had refractory epilepsy. One child died of tumour progression. Follow-up duration in the survivors ranged from 2 to -16 years (mean: 9).Presurgical evaluation included clinical profiles, non-invasive V-EEG monitoring, neuroimaging with MRIs in all; SPECT and PET in selected patients. 54 had intraoperative ECoG. RESULTS: An Engel Class 1 outcome was seen in 78% of the cohort, with 67% being off all AEDs at the most recent follow-up. Children with tumours constituted the majority (56%), with 87% of this group showing a Class 1 outcome and 84% being off AEDs. Children with cortical dysplasia had a Class 1 outcome in 56%. CONCLUSION: Resective brain surgery is an efficacious option in some children with epilepsy. We found ECoG useful to tailor the cortical resection and in our opinion ECoG contributed to the good seizure outcomes.

Classification of clinical semiology in epileptic seizures in neonates.

The clinical semiology of 61 neonatal seizures with EEG correlates, in 24 babies was analysed. Most seizures (89%) had multiple features during the EEG discharge. The seizures were classified using the prominent clinical feature at onset, and all features seen during the seizure, using an extended classification scheme. Orolingual features occurred most frequently at onset (30%), whereas ocular phenomena occurred most often during the seizure (70%). Orolingual, ocular and autonomic features were seen at onset in 55% of the seizures. Seizure onsets with clonic, tonic and hypomotor features were seen in 20%, 8% and 18% respectively. Clinico-electrical correlations were as follows. The EEG discharge involved both hemispheres in 54% of all seizures, in clonic seizures this was 93%. Focal clonic seizures were associated with EEG seizure onset from the contralateral hemisphere. Majority of the clonic and hypomotor seizures had a left hemisphere ictal EEG onset. Orolingual seizures frequently started from the right hemisphere, whereas ocular and autonomic seizures arose from either hemisphere. There was no significant difference in mortality, morbidity, abnormal neuroimaging and EEG background abnormalities in babies with or without clonic seizures. This study provides insights into neuronal networks that underpin electroclinical seizures, by analysing and classifying the obvious initial clinical features and those during the seizure.

Brief electroencephalography rhythmic discharges (BERDs) in the neonate with seizures: their significance and prognostic implications.

We aimed to explore the significance and prognostic implications of paroxysmal brief electroencephalography (EEG) rhythmic discharges (BERDs) in neonatal seizures. The 52 neonates in this study were divided into 3 groups: (1) BERDs only: 9 neonates, (2) BERDs + conventional EEG seizures: 11 babies, (3) Conventional EEG seizures only: 32 babies. We analyzed the BERDs and compared outcomes in the 3 groups: there was no significant difference in mortality and neurodevelopmental or background EEG impairment. Similar to conventional EEG seizures, BERDs are also associated with an increased mortality, morbidity, and EEG background abnormalities. Fewer babies with BERDS appear to develop postneonatal seizures suggesting their epileptogenic potential is less. In the appropriate clinical context, BERDs should be considered as miniseizures.

Ictal electroencephalograms in neonatal seizures: characteristics and associations.

The characteristics of ictal electroencephalograms in 160 neonatal seizures of 43 babies were correlated with mortality and neurodevelopmental outcomes. Neonatal seizures are focal at onset, most frequently temporal, and often occur during sleep. Twenty-one percent of babies with seizures died, and 76% of survivors manifested neurodevelopmental impairment during 2-6-year follow-up. A low-amplitude ictal electroencephalogram discharge was associated with increased mortality, and a frequency of <2 Hz with increased morbidity. Status epilepticus, ictal fractions, multiple foci, and bihemispheric involvement did not influence outcomes. Of 160 seizures, 99 exhibited no associated clinical features (electrographic seizures). Neonatal seizures with clinical correlates (electroclinical seizures) exhibited a higher amplitude and frequency of ictal electroencephalogram discharge than electrographic seizures. During electroclinical seizures, the ictal electroencephalogram was more likely to involve larger areas of the brain and to cross the midline. Mortality and morbidity were similar in babies with electroclinical and electrographic seizures, emphasizing the need to diagnose and treat both types. Ictal electroencephalogram topography has implications for electrode application during limited-channel, amplitude-integrated electroencephalograms. We recommend temporal and paracentral electrodes. Video electroencephalograms are important in diagnosing neonatal seizures and providing useful information regarding ictal electroencephalogram characteristics.

Fast activity during EEG seizures in neonates.

INTRODUCTION: Paroxysmal fast activity (FA) has been proposed as a marker for epileptic networks. We explore the presence and significance of ictal FA on scalp video EEG seizures (EEG Sz) recorded in neonates. METHODOLOGY: Forty two babies had 159 EEG Szs. The seizures were analysed for ictal FA, using a low frequency filter of 30 Hz. We explored the relationship of ictal FA to the occurrence of electroclinical and electrographic seizures, the use of phenobarbitone and to neurodevelopmental outcomes. RESULTS: Ictal FA occurred in 62 (39%) of the 159 EEG Szs. In the 62 seizures with ictal FA, 34 (55%) were electroclinical seizures (ECSz) and 28 (45%) were electrographic (ESz). In the remaining 97 seizures without ictal FA, 27 (28%) were ECSz and 70 (72%) ESz. There was a significant correlation (p=0.0006) between ictal FA and electroclinical seizures. There was no relationship between phenobarbitone and presence of ictal FA. There was no significant difference in the background EEG, neuroimaging abnormalities, neurodevelopmental impairment or post neonatal seizures between those with and without ictal FA. CONCLUSIONS: Ictal FA is highly correlated to the occurrence of clinical features during an EEG seizure. The presence of ictal FA does not appear to influence neurodevelopmental outcomes.

Neurodevelopmental outcomes in neonates with seizures: a numerical score of background encephalography to help prognosticate.

There is a high incidence of mortality and neurodevelopmental sequelae in babies with neonatal seizures. The electroencephalography (EEG) background has been shown to be an excellent predictor of outcome by most studies, with a few suggesting limited value in prognostication. Previous studies suggest poor prognosis with severely abnormal backgrounds, but prediction was difficult with moderate abnormalities. The proposed numerical scoring system for the EEG background provides an objective method of evaluation with improved reproducibility, categorization, and prognostication. Our study showed that the numerical score of EEG background was a good predictor of outcome. Higher numerical scores reflecting greater abnormality of background EEG were associated with increasing incidence of mortality, neurodevelopmental impairment, cerebral palsy, vision and hearing impairment, and epilepsy. The numerical score also correlated with neuroimaging abnormalities. A numerical EEG score can help target interventional strategies for neonatal seizures.