Serial EEG Research Articles

Deep learning for estimation of functional brain maturation from EEG of premature neonates.

EEG monitoring of early brain function and development in neonatal intensive care units may help to identify infants with high risk of serious neurological impairment and to assess brain maturation for evaluation of neurodevelopmental progress. Automated analysis of EEG data makes continuous evaluation of brain activity fast and accessible. A convolutional neural network (CNN) for regression of EEG maturational age of premature neonates from marginally preprocessed serial EEG recordings is proposed. The CNN was trained and validated using 141 EEG recordings from 43 preterm neonates born below 28 weeks of gestation with normal neurodevelop-mental outcome at 12 months of corrected age. The estimated functional brain maturation between the first and last EEG recording increased in each patient. On average over 96% of repeated measures within an infant had an increasing EEG maturational age according to the post menstrual age at EEG recording time. Our algorithm has potential to be deployed to support neonatologists for accurate estimation of functional brain maturity in premature neonates.

Clinical Usefulness of SISCOM-SPM Compared to Visual Analysis to Locate the Epileptogenic Zone.

Introduction: Subtraction of ictal-interictal SPECT co-registered to MRI (SISCOM) is a quantification tool that can improve the sensitivity and specificity of the epileptogenic zone (EZ) localization. Commercially available image analysis software packages for SISCOM are costly, and Statistical Parametric Mapping (SPM) could be an alternative free software for the definition of the EZ. There are only a few studies that compare SISCOM using SPM (SISCOM-SPM) with visual analysis.Aim: To compare SISCOM-SPM vs. visual analysis for localization of the EZ in patients with pharmacoresistant focal epilepsies.Materials and methods: We evaluated all our patients with focal epilepsies that underwent ictal and interictal SPECT. We defined the reference standard to locate the EZ by pathology and follow-up (in patients submitted to surgery), or seizure semiology, serial EEG, long-term video-EEG, 18F-FDG PET/CT, and MRI (in patients who were not operated). We compared the location of the EZ by visual analysis of SPECT images and by SISCOM-SPM to the reference standard and classified as concordant, discordant, or partially concordant.Results: We included 23 patients. Visual analysis was concordant with the EZ reference standard in only 13 patients (56.5%), while SISCOM-SPM was concordant in 18 cases (78.3%), providing a 21.8% increase in the location of EZ. However, this difference was not significant due to the small sample size (p = 0.0856).Conclusion: Our preliminary results demonstrate that, in clinical practice, SISCOM-SPM has the potential to add information that might help localize the EZ compared to visual analysis. SISCOM-SPM has a lower cost than other commercially available SISCOM software packages, which is an advantage for developing countries. Studies with more patients are necessary to confirm our findings.

Predictors of Class I epilepsy surgery outcome in tumour-related chronic temporal lobe epilepsy in adults.

Temporal lobe tumours, especially low-grade gliomas and glioneuronal tumours, are common causes of seizures in patients referred for epilepsy surgery. We here present our experience of surgical treatment of patients with intractable chronic epilepsy associated with temporal lobe tumours, focusing on the long-term surgical outcomes and the features associated with better seizure control. In this study, we retrospectively analysed 44 consecutive patients from a total of 182 with refractory temporal lobe epilepsy presenting with long-term intractable epilepsy due to a temporal lobe tumour who were surgically treated at our institution between 2005 and 2015 with post-surgical follow-up of at least two years. All patients underwent a standard pre-surgical evaluation that included: history and physical examination with a description of the seizure semiology, serial scalp EEG recording, brain MR imaging, and a detailed neuropsychological evaluation. Our surgical strategy comprised tumour resection, and combined mesial temporal and neocortical resection in most cases. No patient died during surgery or the postoperative course. Seven patients had postoperative complications, of whom two had permanent hemiparesis due to ischaemic stroke. At the final follow-up, a favourable seizure outcome (Engel Class I) was found in 37 patients (84%), including 31 (70.5%) in Engel Class IA (excellent result). Two (4.5%) patients presented with an Engel Class II outcome (unfavourable outcome). Five patients (11.5%) were in Engel Classes III or IV (surgical failure). We found that complete resection of the hippocampus along with tumour and temporal pole removal was strongly associated with seizure freedom (p = 0.015). Pathological diagnosis was also a significant prognostic indicator of tumour-related seizure freedom. Patients with a diagnosis of a glioneuronal tumour benefited from more seizure freedom after resection compared to those who had a low-grade glioma (p = 0.024). The most appropriate management of tumour-related chronic temporal lobe epilepsy in adults appears to be tai-lored temporal lobe resection including tumour and hippocampal complex removal. Surgical treatment of tumoural temporal lobe epilepsy demonstrates excellent results in terms of seizure improvement, especially in patients with glioneuronal tumours.

Change of centrotemporal spikes from onset to remission in self-limited epilepsy with centrotemporal spikes (SLECTS)

ObjectiveTo reveal the changes of centrotemporal spikes that occur during the disease course of self-limited epilepsy with centrotemporal spikes (SLECTS). MethodWe retrospectively reviewed the serial EEGs of 63 patients with SLECTS from initial diagnosis to remission. There were 32 patients who did not undergo treatment and 31 patients who underwent treatment with oxcarbazepine (OXC). The change of occurrence or abundance, voltage, and location of centrotemporal spikes of serial EEGs were analyzed and compared between the two groups. Clinical seizure evidenced and reported was counted. The time gap between seizure remission and EEG remission was measured in the two groups. ResultChanges of occurrence or abundance of the centrotemporal spikes were either abrupt (sudden disappearance of the frequent spikes on following EEG) or gradual (decline in number over 2 or more serial EEGs). Pattern of spike disappearance was not significantly different between the medication naïve group and OXC treated group. The spike voltage or the location of centrotemporal spikes did not change during the disease course in most cases. Delay between seizure remission and EEG normalization was 3.34 ± 1.75 (mean ± standard deviation, range: 0.77–7.97) years in untreated patients and 3.03 ± 1.41 (0.95–6.61) years in OXC-treated group. ConclusionPattern of spike disappearance in SLECTS was either abrupt or gradual. Treatment with OXC had no effect in the disappearance pattern. Precise data regarding the pattern of disappearance and delay between seizure remission and EEG normalization can help to understand the evolution of spike in SLECTS and to predict the timing of normalization of EEG after seizure remission.

Rhizomelic chondrodysplasia punctata: Role of EEG as a biomarker of impending epilepsy.

Progressive deterioration of neuroimaging and electroencephalography (EEG) had been described in rhizomelic chondrodysplasia punctata (RCDP); however, serial EEG data showing sequential EEG changes(before and after seizure onset) is lacking. We report a child with a diagnosis of type 1 RCDP, who had a progressive decline in EEG and radiologic findings over a 5 year period. Her first EEG was normal at the age of 8 months. Follow-up EEG at the age of 2 years showed a mild background slowing as well as frequent 1–2 Hz central-parietal spike wave with midline involvement. Just before 3 years of age, she started to seizures, when the EEG showed further worsening with frequent multifocal spikes and bursts of generalized high amplitude spike and spike-wave discharges. The transition of EEG from normal background to the appearance of focal epileptiform abnormality before the seizure onset followed by further deterioration at the seizure onset had not been reported as per our knowledge. This study emphasizes that serial EEGs may provide valuable information about impending seizure activity. Further studies are needed to calculate the lag time between the detection of epileptiform activities and the onset of clinical seizure activities. In addition, research studies are warranted to determine if early (before or at the onset of epileptogenesis rather than after seizure onset) use of replacement therapy or antiepileptic therapy (antiepileptic drugs or diet) can modify epilepsy severity and neurologic prognosis in this devastating disease.

Nonketotic Hyperglycinemia: Two Case Reports and Review

ABSTRACTNonketotic hyperglycinemia (NKH) or glycine encephalopathy is an autosomal recessive disorder of glycine metabolism resulting in an excessive accumulation of glycine in all body tissues, including the central nervous system. It is caused by a biochemical defect in the glycine cleavage system and considered as a rare disorder with an estimated prevalence of 1:60,000. The neonatal form presents in the first few days of life with progressive encephalopathy, hypotonia, myoclonic jerks, hiccups, seizures, rapid progression to coma and often death due to central apnea. Surviving infants often have severe developmental delay and refractory seizures. Atypical forms of NKH present with heterogeneous and nonspecific disease course. Classical glycine encephalopathy usually carries a very poor prognosis. We describe two neonates who presented with neonatal encephalopathy, apnea, and progressive lethargy. Increased CSF glycine level along with an elevated CSF to plasma glycine ratio was suggestive of classic NKH. Burst suppression EEG and agenesis of the corpus callosum were supportive findings. Evolution of the EEG patterns and course of the disease are discussed in detail. Transient phases of clinical stabilization and normalized plasma biochemical results may not necessarily reflect the actual encephalopathic process. Serial EEGs are helpful to assess the efficacy of treatment and to modify the therapeutic approach.

Analysis of serial electroencephalographic predictors of seizure recurrence in Rolandic epilepsy.

We aimed to assess the relationship between electroencephalography (EEG) markers and seizure recurrence in cases with benign epilepsy with centrotemporal spikes (BECT) in a long-term follow-up study. We analyzed the data of 52 children with BECT who were divided into 2 groups: the isolated group and recurrence group. The clinical profiles and initial/serial visual EEG recordings of both groups were evaluated. The entire follow-up period ranged from 12 to 65months. None of the clinical characteristics differed between the 2 groups. Serial EEGs showed that the appearance of Rolandic spikes in the frontal region was more prevalent in the recurrence group. Moreover, a significant correlation was found between bilateral asynchronous discharges and seizure recurrence. However, on initial EEG of these patients, neither of the EEG features exhibited statistical significance. The presence of frontal focus and bilateral asynchrony appeared to be hallmarks of BECT patients with higher risk for seizure recurrence.

P34-T Serial EEG findings in patients with anti-NMDAR encephalitis

Serial EEG findings in patients with anti-NMDAR encephalitis. Background Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable but often misdiagnosed autoimmune encephalitis. Patients present with neuropsychiatric symptoms, impaired consciousness, seizures, autonomic instability, and hypoventilation Electroencephalogram (EEG) abnormalities are very common in anti-NMDAR encephalitis and may contribute to diagnosis at early stages of disease. The aim of the study was to describe serial EEG findings of in patients with anti-NMDAR encephalitis. Material and methods We present detailed clinical, electroencephalographical characteristics and long-term follow-up of five patients with confirmed anti-NMDAR encephalitis. Results All patients had abnormal EEG. The main presentations of abnormal EEG were diffuse slowing, epileptiform discharges, extreme delta brush, polymorphic delta rhythm and focal slowing. The degree of abnormalities correlated with disease progression and diminished along with the clinical improvement. Conclusion The majority of anti-NMDAR encephalitis patients had abnormal EEG. EEG could sensitively reflect the abnormal brain functions of patients and could assist with early clinical diagnosis and prognosis prediction.

Treatment Options for Anti-N-methyl-D-aspartate Receptor Encephalitis

ABSTRACTAnti-NMDAR encephalitis is an autoimmune limbic disorder with an unknown cause, which affects mostly young women. Behavioral changes, seizures, orofacial muscle contractions, and memory impairment are usually observed. The variability of the symptoms depends on which part of the brain is inflamed. Treatment options aim to reduce serious neurological damage. Early diagnosis combined with the proper treatment favorably impacts the outcome. In our facility, weekly induction therapy is started pending an investigation into an associated ovarian or other tumor. Two case studies are discussed with favorable outcomes. The first is an outstanding case study with refractory status epilepticus caused by anti-NMDA receptors with benign teratoma which improved following combination therapy with rituximab and cyclophosphamide. There was no response to benzodiazepines and to an abundant number of antiepileptic drugs. Brain magnetic resonance imaging clearly indicated severe brain atrophy in the first case. Serial EEG monitoring showed a multitude of abnormalities. Delta brush activity was interictal and distinctive of anti-NMDAR encephalitis.

EEG Differences in Two Clinically Similar Rapid Dementias: Voltage-Gated Potassium Channel Complex-Associated Autoimmune Encephalitis and Creutzfeldt-Jakob Disease.

Distinguishing treatable causes for rapidly progressive dementia from those that are incurable is vital. Creutzfeldt-Jakob disease (CJD) and voltage-gated potassium channel complex-associated autoimmune encephalitis (VGKC AE) are 2 such conditions with disparate outcomes and response to treatment. To determine the differences in electroencephalography between CJD and VGKC AE, we performed a retrospective review of medical records and examined clinical data, neuroimaging, and electroencephalographs performed in patients admitted for evaluation for rapidly progressive dementia diagnosed with CJD and VGKC AE at the Johns Hopkins Hospital and Bayview Medical Center between January 1, 2007 and December 31, 2015. More patients in the VGKC AE group had seizures (12/17) than those with CJD (3/14; P = .008). Serum sodium levels were lower in those with VGKC AE (P = .001). Cerebrospinal fluid (CSF) white blood cell count was higher in VGKC AE (P = .008). CSF protein 14-3-3 (P = .018) was more commonly detected in CJD, and tau levels were higher in those with CJD (P < .006). On neuroimaging, diffusion restriction in the cortex (P = .001), caudate (P < .001), and putamen (P = .001) was more frequent in CJD. Periodic sharp wave complexes (P = .001) and generalized suppressed activity (P = .008) were more common on initial EEG in CJD. On serial EEGs, generalized periodic discharges (P = .004), generalized suppressed activity (P=0.008), and periodic sharp wave complexes (P < .001) were detected more in CJD. This study shows that there are a number of differentiating features between CJD and VGKC AE, and electroencephalography can aid in their diagnoses. Performing serial EEGs better delineates these conditions.

S22. Value of emergent EEG in the diagnosis and management of patients with acute altered mental status

Introduction Status epilepticus (SE), considered the most extreme form of a seizure, is one of the most important complications in neurologic patients and an emergency that requires treatment adjustment. In critically ill patients, most of the seizures are non convulsive, and they would be unnoticed without continuous EEG (cEEG) monitoring. It is important to diagnose these patients as early as possible as there is evidence supporting that ictal activity may further compromise at risk brain tissue following acute brain insults. There are countries where cEEG monitoring is easily accessible and it is performed as part of the brain monitoring protocol. Nevertheless, in Spain as in many other countries, cEEG is rarely available, thus, serial routine EEGs are used for this purpose. There is scarce data of the efficiency of routine emergent EEGs (EmEEG) in patients with altered mental status (AMS). Our aim is to reaffirm the utility of EmEEG and to define the clinical spectrum of potentially eligible patients. We want to evaluate whether clinical features can help predict which patients have a high probability of being in NCSE and thus should undergo an emergent EEG. Methods In a first phase, we have reviewed the EEG requested as emergent during business hours and on-call shifts for 6 months. We have included patients with suspicion of status epilepticus, and with an EEG performed within the first 3 h of the request. In a second phase, we are analyzing prospectively patients with the same inclusion criteria, and we are adding the perspective of the clinicians who ordered the test, asking them to anonymously answer a survey, considering whether the results were helpful for the diagnosis and management of these patients. Results In the first phase we have analyzed 232 EmEEGs, 129 during business hours and 103 during call shifts. Twenty-eight (12%) showed an SE, from whom 23 (82.1%) were NCSE and 10 were in patients in coma. NCSE was most frequently detected in patients with a previous lesion (28%), an acute cerebral injury (14%) and a history of epilepsy (14.2%). The most common symptom was an alteration in mental status, followed by motor manifestations, agitation and a language disorder. Conclusion There is a high incidence of NCSE in patients with altered mental status. Obtaining an emergent EEG is not only crucial for the right diagnosis and management of patients in SE, it also provides relevant information in the population of patients with AMS of unknown etiology.

S94. Stability of early EEG background patterns after pediatric cardiac arrest

Introduction We aimed to determine whether EEG background characteristics remain stable across discrete time periods during the acute period after resuscitation from pediatric cardiac arrest. Methods Children resuscitated from cardiac arrest underwent continuous conventional EEG monitoring. The EEG was scored in 12-h epochs for up to 72-h after return of circulation by an electroencephalographer using a Background Category with four-levels (normal, slow-disorganized, discontinuous/burst-suppression, or attenuated-featureless) or two-levels (normal/slow-disorganized or discontinuous/burst-suppression/attenuated-featureless). Survival analyses and mixed-effects ordinal logistic regression models evaluated whether the EEG remained stable across epochs. Results EEG monitoring was performed in 89 consecutive children. When EEG was assessed as the four-level Background Category 30% of subjects changed category over time. Based on initial Background Category, one quarter of subjects changed EEG category by 24 h if the initial EEG was attenuated-featureless, by 36 h if the initial EEG was discontinuous or burst-suppression, by 48 h if the initial EEG was slow-disorganized, and never if the initial EEG was normal. However, regression modeling for the four-level Background Category indicated that the EEG did not change over time (OR = 1.06, 95%CI = 0.96– 1.17, p = 0.26). Similarly, when EEG was assessed as the two-level Background Category, 8% of subjects changed EEG category over time. However, regression modeling for the two-level category indicated that the EEG did not change over time (OR = 1.02, 95%CI = 0.91–1.13, p = 0.75). Conclusion The EEG Background Category changes over time whether analyzed as four-levels (30% of subjects) or two-levels (8% of subjects) although regression analyses indicated no significant changes occurred over time for the full cohort. These data indicate that the Background Category is often stable during the acute 72 h after pediatric cardiac arrest and thus may be a useful EEG assessment metric in future studies, but that some subjects do have EEG changes over time and therefore serial EEG assessments may be informative.

F57. EEG findings in pediatric parainfectious acute bilateral striatal necrosis

Acute bilateral striatal necrosis (ABSN) is a clinicoradiological syndrome with different causes: genetic (mostly, inborn errors of metabolism) and acquired. Among these, parainfectious forms are especially relevant, since they may be confused with genetic forms, but carry a better prognosis and may benefit from immunomodulation. ABSN presents with any combination of movement disorders, altered state of awareness and seizures. The latter warrant an EEG, likely to be performed before imaging can confirm the syndromic diagnosis. To describe the electroclinical findings of pediatric patients with confirmed parainfectious ABSN attending our hospital between 01/2015 and 12/2015. Retrospective review of clinical records of patients fulfilling the following: Age at onset ⩽16 years. Onset of movement disorders, altered level of awareness or seizures within 3 weeks of a febrile episode. Acute bilateral neostriatal lesions (enlargement and T2/Flair hyperintensity on MR or hypodensity on CT of caudate and/or putamen bilaterally). Evidence of recent/ongoing infection in biological samples (Direct: Positive culture/PCR; Indirect: Seroconversion/Raising antibody titres). Progressive course after 6 weeks Evidence of a metabolic disorder (Positive genetic testing for pathogenic mutations or confirmed altered enzyme activity/altered biochemical markers in biological samples). Alternative cause. We found 2 cases: 1. 11 year old boy presenting with focal seizures and parkinsonism, 48 h after a febrile episode. MR showed symmetric striatal inflammation and patchy cortical edema, predominantly frontal. CSF analysis showed mononuclear pleocytosis and increased protein. A tracheal aspirate disclosed M. pneumoniae infection. Metabolic screening was negative. Control of seizures was difficult, requiring combined treatment with LEV, LCM, VPA, Antibiotics, IVIG and glucocorticoids. Serial EEGs showed diffuse background slowing and focal asymmetric fronto-temporal slowing (right worse). He was discharged asymptomatic after 13 days, on LEV and LCM, which were stopped over the following 5 months. MR and EEG were normal 3 months after onset. 2: 2 year old girl presenting with parkinsonism, dystonia and bulbar symptoms 7 days after a febrile episode. MR showed symmetric striatal inflammation. CSF analysis was normal, but HHV6 replication was shown in plasma and CSF. EEG was normal. Metabolic screening showed raised urinary 3-OH-glutaric acid, not confirmed on repeated tests. She was treated with foscarnet, IVIG and glucocorticoids and was discharged after 43 days, with mild symptoms. She was asymptomatic at 8 months follow-up. Control MR showed atrophy and cavitation of posterior putamina. EEG allows objective assessment and monitoring of brain function in parainfectious ABSN, when it presents with seizures and/or altered level of awareness. Focal abnormalities may correlate with damage beyond the striatum and into the cortex.

Stability of Early EEG Background Patterns After Pediatric Cardiac Arrest.

We aimed to determine whether EEG background characteristics remain stable across discrete time periods during the acute period after resuscitation from pediatric cardiac arrest. Children resuscitated from cardiac arrest underwent continuous conventional EEG monitoring. The EEG was scored in 12-hour epochs for up to 72 hours after return of circulation by an electroencephalographer using a Background Category with 4 levels (normal, slow-disorganized, discontinuous/burst-suppression, or attenuated-featureless) or 2 levels (normal/slow-disorganized or discontinuous/burst-suppression/attenuated-featureless). Survival analyses and mixed-effects ordinal logistic regression models evaluated whether the EEG remained stable across epochs. EEG monitoring was performed in 89 consecutive children. When EEG was assessed as the 4-level Background Category, 30% of subjects changed category over time. Based on initial Background Category, one quarter of the subjects changed EEG category by 24 hours if the initial EEG was attenuated-featureless, by 36 hours if the initial EEG was discontinuous or burst-suppression, by 48 hours if the initial EEG was slow-disorganized, and never if the initial EEG was normal. However, regression modeling for the 4-level Background Category indicated that the EEG did not change over time (odds ratio = 1.06, 95% confidence interval = 0.96-1.17, P = 0.26). Similarly, when EEG was assessed as the 2-level Background Category, 8% of subjects changed EEG category over time. However, regression modeling for the 2-level category indicated that the EEG did not change over time (odds ratio = 1.02, 95% confidence interval = 0.91-1.13, P = 0.75). The EEG Background Category changes over time whether analyzed as 4 levels (30% of subjects) or 2 levels (8% of subjects), although regression analyses indicated that no significant changes occurred over time for the full cohort. These data indicate that the Background Category is often stable during the acute 72 hours after pediatric cardiac arrest and thus may be a useful EEG assessment metric in future studies, but that some subjects do have EEG changes over time and therefore serial EEG assessments may be informative.

Neonatal EEG- an overview

Electro-encephalogram (EEG) is the best non-invasive modality for brain monitoring. As brain continues to develop and mature in neonatal period, EEG of a normal newborn varies from time to time. Wave patterns may be normal at one developmental stage and abnormal at another stage. There are many types of EEG waves like alpha, beta, gamma & delta waves. Burst suppression occurs in very sick neonates following brain damage due to asphyxia & predicts poor prognosis. Isoelectric pattern occurs in severe asphyxia, circulatory collapse, massive intracerebral hemorrhage, severe inborn metabolic deficits, CNS bacterial or viral infections, drug-induced state, hypothermia, postictal recording and in malformations like hydranencephaly or massive hydrocephalus. Grading of severity of disease condition can be done based on EEG. They can be vital in arriving etiological diagnosis. EEG distinguishes between normal paroxysmal movements from epileptic seizures. Nearly 90% of abnormal movements mimiking seizures may be nonepileptic after EEG study. Early recordings, prolonged recordings at different activity states, serial short interval EEGs increase the prognostic value of EEGs. Long-time bedside monitoring of brain function can be done by amplitude-integrated EEG (aEEG). Some rare neonatal epilepsy syndromes have characteristic EEG features. Artifacts mimicking electrical seizures include environmental interference, electrode impedence abnormalities, motion artifacts and endogenous non-cerebral potentials which can be distinguished by Polygraphy. Drugs can alter background activity. EEG is a boon for noninvasive bedside continuous monitoring of the brain. Judicious application of this technique can help in prompt management of various pathologies like seizures , encephalopathies, epilepsy and asphyxia.

Is inpatient ictal video-electroencephalographic monitoring mandatory in mesial temporal lobe epilepsy with unilateral hippocampal sclerosis? A prospective study.

To compare surgical outcome in mesial temporal lobe epilepsy (MTLE) patients with unilateral hippocampal sclerosis (MTLE-HS) who had or did not have preoperative video-electroencephalographic monitoring (VEEG). A prospective study was undertaken with 166 consecutive pharmacoresistant unilateral MTLE-HS patients. All patients were investigated with detailed seizure semiology, serial routine outpatient EEG, magnetic resonance imaging, neuropsychological evaluation, and if necessary, other examinations. Postoperative follow-up ranged between 2 and 16years. Patients were divided into: (1) patients operated on based on routine outpatient EEG information, with >80% of EEGs with unilateral interictal epileptiform discharges (IEDs) ipsilateral to HS or ictal events (n=71); and (2) patients submitted to preoperative VEEG (n=95). To avoid the bias generated by ictal recordings, we performed a subanalysis of: (1) patients without preoperatively ictal recordings (n=80) and (2) patients with ictal recordings in VEEG or routine outpatient EEG (n=86). Groups were similar regarding gender, age at surgery, seizure onset, preoperative seizure frequency, and duration of follow-up. Overall, 136/166 (81.92%) were classified as Engel I seizure outcome, with no difference between groups; 76.84% and 88.73% of patients with and without VEEG, respectively, had Engel I postoperative seizure outcome (P=.77). The time lag until surgery was shorter in the group without VEEG (80 vs 38months; P=.01). Considering ictal recordings, 76.74% of patients with seizures recorded and 87.50% without ictal recordings had Engel I outcome (P=.11). We performed the first prospective study in a tertiary epilepsy center comparing surgical outcomes in unilateral MTLE-HS patients investigated preoperatively with and without VEEG. Based on the surgical outcome, VEEG is not imperative in patients with unilateral MTLE-HS who have compatible semiology and clearly ipsilateralized IEDs evaluated by a multidisciplinary and experienced epilepsy group.

Utility of EEG Activation Procedures in Epilepsy: A Population-Based Study.

No previous population-based study has addressed the contribution of activation procedures to the yield of epileptiform abnormalities on serial EEGs. We assessed yield of activation-related epileptiform abnormalities and predictors of finding an activation-related abnormality with multiple EEGs in a population-based study of newly diagnosed epilepsy. We used the resources of the Rochester Epidemiology Project to identify 449 residents of Rochester, Minnesota with a diagnosis of newly diagnosed epilepsy at age 1 year or older, between 1960 and 1994, who had at least one EEG. Information on all activation procedures (i.e., sleep, hyperventilation, and photic activation) and seizure/epilepsy characteristics was obtained by comprehensive review of medical records. At the first EEG, the yield of epileptiform abnormalities was greatest for individuals 1 to 19 years of age at diagnosis, for each activation procedure. The yield in patients aged 1 to 19 versus ≥20 years was 21.6% versus 10.3% for sleep, 6.5% versus 3.3% for photic stimulation, and 10.3% versus 5% for hyperventilation. Among young people (aged 1-19 years), sleep was associated with an increased likelihood of finding an activation-related abnormality on any EEG. The likelihood of finding an activation-related abnormality on any EEG was decreased for postnatal symptomatic and for unknown etiology. Among activation procedures, sleep showed the highest yield of epileptiform abnormalities. There was a low yield for photic stimulation and hyperventilation. Within each activation procedure, younger age at diagnosis had the greatest yield. Sleep is the most effective activation procedure, especially in younger patients, and should be performed when possible.

Functional maturation in preterm infants measured by serial recording of cortical activity

Minimally invasive, automated cot-side tools for monitoring early neurological development can be used to guide individual treatment and benchmark novel interventional studies. We develop an automated estimate of the EEG maturational age (EMA) for application to serial recordings in preterm infants. The EMA estimate was based on a combination of 23 computational features estimated from both the full EEG recording and a period of low EEG activity (46 features in total). The combination function (support vector regression) was trained using 101 serial EEG recordings from 39 preterm infants with a gestational age less than 28 weeks and normal neurodevelopmental outcome at 12 months of age. EEG recordings were performed from 24 to 38 weeks post-menstrual age (PMA). The correlation between the EMA and the clinically determined PMA at the time of EEG recording was 0.936 (95%CI: 0.932–0.976; n = 39). All infants had an increase in EMA between the first and last EEG recording and 57/62 (92%) of repeated measures within an infant had an increasing EMA with PMA of EEG recording. The EMA is a surrogate measure of age that can accurately determine brain maturation in preterm infants.

The Reemergence of EEG Reactivity After Cardiac Arrest.

Electroencephalogram (EEG) reactivity has been increasingly utilized in prognostication after cardiac arrest. Recent studies have demonstrated a false-positive rate of 0% in predicting poor outcome with a nonreactive EEG. The reemergence of reactivity after an initial nonreactive EEG has been noted in cases of drug intoxication, rewarming after hypothermia, and after discontinuing sedation. This is the first case describing the reemergence of EEG reactivity without the confounding factors listed above. We describe a case of resuscitated cardiac arrest with initial EEG demonstrating a lack of reactivity. A repeat EEG completed 3 days later revealed a reemergence of reactivity in the setting of normothermia, a negative drug screen, and the absence of sedation. The delayed recovery of EEG reactivity without previously established confounding factors is novel. Serial EEGs may be beneficial as the available literature on reactivity and prognostication is based on an average of 24 to 48 hours of EEG tracing. Prognostication after cardiac arrest continues to require a multimodal approach.

Syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL): A case report with serial electroencephalography (EEG) recordings.. Is there an association with human herpes virus type 7 (HHV-7) infection?

Introduction The syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is a diagnosis made by exclusion. In the literature, different etiological explanations are proposed for HaNDL, including an immune-mediated reaction after a viral infection. Case description We present a case of a 23-year-old woman with several episodes of transient headache, neurological deficits and cerebrospinal fluid lymphocytosis. All diagnostic criteria for the HaNDL syndrome were fulfilled; however, additional cerebrospinal fluid analysis showed a positive polymerase chain reaction (PCR) for human herpes virus type 7 (HHV-7). Discussion The possible role of a (prodromal) viral infection in the etiology of HaNDL is discussed. Also the role of electroencephalography (EEG) recordings is discussed. Serial EEG recordings showed generalized slowing, frontal intermittent rhythmic delta activity (FIRDA) and symmetric triphasic frontal waves with a dilation lag.