The diagnostic value of initial video-EEG monitoring in children—Review of 1000 cases

The assessment of the knowledge and practices of healthcare providers regarding paroxysmal non-epileptic events (PNES) in children: A cross-sectional study

OBJECTIVE

Paroxysmal non-epileptic events (PNEs) are a group of disorders that may be misdiagnosed as epilepsy. This study has aimed to assess the knowledge and practices of family physicians and pediatricians regarding the diagnosis, treatment, and follow-up of PNEs in children.

METHODS

The study was designed as a prospective cross-sectional study that was conducted between March 1, 2022, and June 1, 2022, by reaching pediatric specialists and assistants, family physicians, subspecialty assistants, and subspecialists using a Google questionnaire. The survey consists of 26 questions. The questionnaire used by the researchers was prepared in accordance with the literature search and it included detailed questions on the diagnosis, treatment, and differential diagnosis of PNEs.

RESULTS

A total of 37.3% worked as specialists. Most of the participants (41.3%) have worked in training and research hospitals, and 44.3% have been physicians for 6-10 years. The mean and standard deviation for the total score were 10.1 ± 2.6. The scores of family physicians were statistically lower than those of specialists, subspecialty assistants, and subspecialists. A total of 67.2% left the decision of whether the patient should stop taking their medication to another clinician. 45% of the doctors said that they were uncomfortable with the diagnosis.

SIGNIFICANCE

The study findings emphasized the significant knowledge gap among healthcare providers regarding PNEs in children, highlighting the need for targeted educational interventions to improve their understanding and diagnostic skills in this area.

Diagnostic yield and limitations of in-hospital documentation in patients with epilepsy

OBJECTIVE

To determine the diagnostic yield of in-hospital video-electroencephalography (EEG) monitoring to document seizures in patients with epilepsy.

METHODS

Retrospective analysis of electronic seizure documentation at the University Hospital Freiburg (UKF) and at King's College London (KCL). Statistical assessment of the role of the duration of monitoring, and subanalyses on presurgical patient groups and patients undergoing reduction of antiseizure medication.

RESULTS

Of more than 4800 patients with epilepsy undergoing in-hospital recordings at the two institutions since 2005, seizures with documented for 43% (KCL) and 73% (UKF).. Duration of monitoring was highly significantly associated with seizure recordings (p < .0001), and presurgical patients as well as patients with drug reduction had a significantly higher diagnostic yield (p < .0001). Recordings with a duration of >5 days lead to additional new seizure documentation in only less than 10% of patients.

SIGNIFICANCE

There is a need for the development of new ambulatory monitoring strategies to document seizures for diagnostic and monitoring purposes for a relevant subgroup of patients with epilepsy in whom in-hospital monitoring fails to document seizures.

Assessing 72 h vs. 24 h of long-term video-EEG monitoring to confirm the diagnosis of epilepsy: a retrospective observational study

Introduction

Paroxysmal seizure-like events can be a diagnostic challenge. Inpatient video-electroencephalography (EEG) monitoring (VEM) can be a valuable diagnostic tool, but recommendations for the minimal duration of VEM to confirm or rule out epilepsy are inconsistent. In this study, we aim to determine whether VEM of 48 or 72 h was superior to 24 h.

Methods

In this monocentric, retrospective study, we included 111 patients with paroxysmal, seizure-like events who underwent at least 72 h of VEM. Inclusion criteria were as follows: (1) Preliminary workup was inconclusive; (2) VEM admission occurred to confirm a diagnosis; (3) At discharge, the diagnosis of epilepsy was conclusively established. We analyzed the VEM recordings to determine the exact time point of the first occurrence of epileptic abnormalities (EAs; defined as interictal epileptiform discharges or electrographic seizures). Subgroup analyses were performed for epilepsy types and treatment status.

Results

In our study population, 69.4% (77/111) of patients displayed EAs during VEM. In this group, the first occurrence of EAs was observed within 24 h in 92.2% (71/77) of patients and within 24-72 h in 7.8% (6/77). There was no statistically significant difference in the incidence of EA between medicated and non-medicated patients or between focal, generalized epilepsies and epilepsies of unknown type. Of the 19 recorded spontaneous electroclinical seizures, 6 (31.6%) occurred after 24 h.

Discussion

A VEM of 24 h may be sufficient in the diagnostic workup of paroxysmal seizure-like events under most circumstances. Considering the few cases of first EA in the timeframe between 24 and 72 h, a prolonged VEM may be useful in cases with a high probability of epilepsy or where other strategies like sleep-EEG or ambulatory EEG show inconclusive results. Prolonged VEM increases the chance of recording spontaneous seizures. Our study also highlights a high share of subjects with epilepsy that do not exhibit EAs during 72 h of VEM.

The Effect of Smartphone Video on Lead Time to Diagnosis of Infantile Spasms

OBJECTIVE

To assess whether access to smartphone video capture of infantile spasms at initial presentation is associated with improved time to diagnosis and treatment.

METHODS

We conducted a collaborative retrospective cohort study of 80 consecutive infants with confirmed infantile epileptic spasms syndrome initially presenting from 2015 to 2021 at 2 US pediatric centers. Statistical methods used included Mann-Whitney U test to assess the difference in lead times to electroencephalogram (EEG), diagnosis, and treatment between groups with and without video capture. A χ2 analysis was used to assess differences in demographics, clinical characteristics, and treatment outcomes between groups. Multivariate regression analysis was used to account for etiology types and infantile spasms capture on EEG.

RESULTS

Patients with smartphone video infantile spasms capture initially presented a median of 9 days earlier (P = .02), had their first EEG 16 days earlier (P = .007), and were diagnosed and started treatment 17 days earlier (P = .006 and P = .008, respectively) compared with the nonvideo group. The video group had a 25% greater response to initial standard treatment (P = .02) and a 21% greater freedom from infantile spasms at long-term follow-up (P = .03), although this long-term outcome lost statistical significance after adjustment for etiology type (P = .07) and EEG capture of infantile spasms (P = .059).

CONCLUSION

Our findings suggest a benefit of smartphone video capture of infantile spasms in reduced time to diagnosis and initial standard treatment, which are associated with improved treatment response rates. Substantial differences in lead times and treatment response highlight the clinical importance of pediatricians recommending caregivers to obtain smartphone video of events concerning for infantile spasms.

Non-epileptic paroxysmal events at pediatric video-electroencephalography monitoring unit over a 15-year period

OBJECTIVE

Non-epileptic paroxysmal events (NEPEs) are common in pediatric patients and may be misdiagnosed as epileptic seizures. We aimed to study the distribution of NEPEs across age groups and with different comorbidities, and to correlate the patients' presenting symptoms with their final diagnosis after video-EEG.

METHODS

We retrospectively analyzed video-EEG recordings of children aged one month to 18 years who were admitted between March 2005 and March 2020. Patients who experienced any NEPE while under video-EEG monitorization were evaluated in this study. Subjects with concomitant epilepsy were also included. The patients were first divided into 14 groups according to the basic characteristics of symptoms they reported at admission. The events captured on video-EEG were then classified into six NEPE categories based on the nature of the events. These groups were compared according to video-EEG results.

RESULTS

We retrospectively evaluated 1338 records of 1173 patients. The final diagnosis was non-epileptic paroxysmal event in 226 (19.3%) of 1173 patients. The mean age of the patients was 105.4 ± 64.4 months at the time of the monitoring. The presenting symptoms were motor in 149/226 (65.9%) patients, with jerking being the most common (n = 40, 17.7%). Based on video-EEG, the most common NEPE was psychogenic non-epileptic seizures (PNES) (n = 66, 29.2%), and the most common PNES subtype was major motor movements (n = 19/66, 28.8%). Movement disorders (n = 46, 20.4%) were the second most common NEPE and the most common NEPE (n = 21/60, 35%) in children with developmental delay (n = 60). Other common NEPEs were physiological motor movements during sleep (n = 33, 14.6%), normal behavioral events (n = 31, 13.7%), and sleep disorders (n = 15, 6.6%). Almost half of the patients had a prior diagnosis of epilepsy (n = 105, 46.5%). Following the diagnosis of NEPE, antiseizure medication (ASM) was discontinued in 56 (24.8%) patients.

CONCLUSION

Non-epileptiform paroxysmal events can be difficult to distinguish from epileptic seizures in children, especially in patients with developmental delay, epilepsy, abnormal interictal EEG, or abnormal MRI findings. Correct diagnosis of NEPEs by video-EEG prevents unnecessary ASM exposure in children and guides appropriate management of NEPEs.

The Noninvasive Evaluation for Minimally Invasive Pediatric Epilepsy Surgery (MIPES): A Multimodal Exploration of the Localization-Based Hypothesis

Minimally invasive pediatric epilepsy surgery (MIPES) is a rising technique in the management of focal-onset drug-refractory epilepsy. Minimally invasive surgical techniques are based on small, focal interventions (such as parenchymal ablation or localized neuromodulation) leading to elimination of the seizure onset zone or interruption of the larger epileptic network. Precise localization of the seizure onset zone, demarcation of eloquent cortex, and mapping of the network leading to seizure propagation are required to achieve optimal outcomes. The toolbox for presurgical, noninvasive evaluation of focal epilepsy continues to expand rapidly, with a variety of options based on advanced imaging and electrophysiology. In this article, we will examine several of these diagnostic modalities from the standpoint of MIPES and discuss how each can contribute to the development of a localization-based hypothesis for potential surgical targets.

Interictal localization of the epileptogenic zone: Utilizing the observed resonance behavior in the spectral band of surrounding inhibition

Introduction

The gold standard for identification of the epileptogenic zone (EZ) continues to be the visual inspection of electrographic changes around seizures' onset by experienced electroencephalography (EEG) readers. Development of an epileptogenic focus localization tool that can delineate the EZ from analysis of interictal (seizure-free) periods is still an open question of great significance for improved diagnosis (e.g., presurgical evaluation) and treatment of epilepsy (e.g., surgical outcome).

Methods

We developed an EZ interictal localization algorithm (EZILA) based on novel analysis of intracranial EEG (iEEG) using a univariate periodogram-type power measure, a straight-forward ranking approach, a robust dimensional reduction method and a clustering technique. Ten patients with temporal and extra temporal lobe epilepsies, and matching the inclusion criteria of having iEEG recordings at the epilepsy monitoring unit (EMU) and being Engel Class I ≥12 months post-surgery, were recruited in this study.

Results

In a nested k-fold cross validation statistical framework, EZILA assigned the highest score to iEEG channels within the EZ in all patients (10/10) during the first hour of the iEEG recordings and up to their first typical clinical seizure in the EMU (i.e., early interictal period). To further validate EZILA's performance, data from two new (Engel Class I) patients were analyzed in a double-blinded fashion; the EZILA successfully localized iEEG channels within the EZ from interictal iEEG in both patients.

Discussion

Out of the sampled brain regions, iEEG channels in the EZ were most frequently and maximally active in seizure-free (interictal) periods across patients in specific narrow gamma frequency band (∼60-80 Hz), which we have termed focal frequency band (FFB). These findings are consistent with the hypothesis that the EZ may interictally be regulated (controlled) by surrounding inhibitory neurons with resonance characteristics within this narrow gamma band.

Staring Spells: An Age-based Approach Toward Differential Diagnosis

Evaluations to rule out epileptic vs nonepileptic staring spells may entail unnecessary evaluations that can be costly and time consuming. Our study aims to identify common etiologies for staring spells across 3 different pediatric age groups and to propose an age-based clinical guidance to help determine which patients warrant further workup. Methods: This was a single-center retrospective chart analysis of 1496 patients aged 0.0-17.9 years presenting with confirmed staring spell diagnosis from January 2011 to January 2021. The patients were divided into 3 groups based on their age: 0.0-2.9, 3.0-12.9, and 13.0-17.9 years. Patient information collected included demographics, clinical presentation, comorbidities, and final diagnosis. Multilevel likelihood ratios and a receiver operating characteristic curve were determined using 8 of the 11 clinical variables. A total of 1142 patients who met the inclusion criteria were included for the final analysis. The most common final diagnosis was attention-deficit hyperactivity disorder (ADHD) (35%), followed by normal behavior (33%). Generalized and focal epilepsy were diagnosed in 8% and 4% of the patients, respectively. In the 0.0-2.9-year age group, normal behavior was the final diagnosis in 72% patients. In the 3.0-12.9-year and 13.0-17.9-year age groups, ADHD was the most frequent final diagnosis in 46% and 60%, respectively. Overall, ADHD and normal behaviors remain the most common final diagnoses. Multilevel likelihood ratios can be used to develop an age-based guidance to differentiate between epileptic and nonepileptic staring spell diagnoses.

Role of Video-EEG in Children

Routine electroencephalogram (EEG) has many limitations, especially the inability to capture reported habitual events in question. A prolonged EEG with synchronized video (video-EEG) overcomes some of these limitations by improving the sensitivity, specificity and the diagnostic yield by attempting to record the habitual events when they are frequent and when indicated. Video-EEG is employed commonly for the diagnosis and classification of epilepsy/epilepsy syndromes, to distinguish between seizures and seizures mimickers, for pre-surgical evaluation and in the management of critically ill children. The duration of recording would vary depending on the indication and frequency of events. Ambulatory EEG is another cost effective and convenient alternative in certain circumstances. However, availability of the machines and expertise, accessibility, affordability and labor intensive nature of the procedure limit widespread use in India. This review explores the role of video-EEG in the management of children with epileptic and non-epileptic paroxysmal events with respect to routine clinical practice in India.

Importance of access to epilepsy monitoring units during the COVID-19 pandemic: Consensus statement of the International League against epilepsy and the International Federation of Clinical Neurophysiology

Restructuring of healthcare services during the COVID-19 pandemic has led to lockdown of Epilepsy Monitoring Units (EMUs) in many hospitals. The ad-hoc taskforce of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) highlights the detrimental effect of postponing video-EEG monitoring of patients with epilepsy and other paroxysmal events. The taskforce calls for action to continue functioning of Epilepsy Monitoring Units during emergency situations, such as the COVID-19 pandemic. Long-term video-EEG monitoring is an essential diagnostic service. Access to video-EEG monitoring of the patients in the EMUs must be given high priority. Patients should be screened for COVID-19, before admission, according to the local regulations. Local policies for COVID-19 infection control should be adhered to during the video-EEG monitoring. In cases of differential diagnosis where reduction of antiseizure medication is not required, consider home video-EEG monitoring as an alternative in selected patients.

The influence of the abundance and morphology of epileptiform discharges on diagnostic accuracy: How many spikes you need to spot in an EEG

OBJECTIVE

The operational definition of interictal epileptiform discharges (IEDs) of the International Federation of Clinical Neurophysiology (IFCN) described six morphological criteria. Our objective was to assess the impact of pattern-repetition in the EEG-recording, on the diagnostic accuracy of using the IFCN criteria. For clinical implementation, specificity over 95% was set as target.

METHODS

Interictal EEG-recordings of 20-minutes, containing sharp-transients, from 60 patients (30 with epilepsy and 30 with non-epileptic paroxysmal events) were evaluated by three experts, who first marked IEDs solely based on expert opinion, and then, independently from the first session evaluated the presence of the IFCN criteria for each sharp-transient. The gold standard was derived from long-term video-EEG recordings of the patientś habitual paroxysmal episodes.

RESULTS

Presence of at least one discharge fulfilling five criteria provided a specificity of 100% (sensitivity: 70%). For discharges fulfilling fewer criteria, a higher number of discharges was needed to keep the specificity over 95% (5 discharges, when only 3 criteria were fulfilled). A sequential combination of these sets of criteria and thresholds provided a specificity of 97% and sensitivity of 80%.

CONCLUSIONS

Pattern-repetition and IED morphology influence diagnostic accuracy.

SIGNIFICANCE

Systematic application of these criteria will improve quality of clinical EEG interpretation.

Benefits, safety and outcomes of long-term video EEG monitoring in pediatric patients

OBJECTIVE

To investigate benefits of in-hospital, long-term video EEG monitoring (LVEM) for pediatric patients, from a therapeutic perspective and from the perspectives of patients and their families.

METHODS

A monocentric retrospective cohort study was conducted. Patients aged 0-18 years who underwent LVEM for epilepsy surgery eligibility, epilepsy syndrome clarification, or medication adjustment were evaluated regarding paroxysmal event type, change in seizure frequency and patients' benefits using a standardized evaluation protocol.

RESULTS

A total of 163 (88 boys and 75 girls, mean age 10.9 years) pediatric patients underwent 178 LVEM sessions, with a mean duration of 5.4 days. The rate of habitual event detection was 69.1%. Epilepsy diagnosis was confirmed in 147 patients and excluded in 16 patients (9.8%). LVEM results altered the diagnosis of 37.4% of patients. Diagnosis remained unchanged in 49.1% of patients and was specified in 13.5% of patients. Epilepsy surgery was performed in 32 patients, and 64% of epilepsy patients deemed ineligible for epilepsy surgery underwent medication adjustments. Patients or their families found LVEM helpful in 75% of cases. Significant seizure reductions and improvements in the disease course were reported by 45% of epilepsy patients. Three episodes of non-convulsive status epilepticus occurred, representing 1.7% of admissions and 1.9% of patients diagnosed with epilepsy, while no injuries were observed.

CONCLUSIONS

LVEM is beneficial for pediatric patients from both a medical perspective and from the perspective of patients and their families, even if patients are ineligible for epilepsy surgery. LVEM is well-tolerated with a low risk of status epilepticus and injuries.

Optimized set of criteria for defining interictal epileptiform EEG discharges

OBJECTIVE

To find and validate the optimal combination of criteria that define interictal epileptiform EEG discharges (IEDs). Our target was a specificity over 95%, to avoid over-reading in clinical EEG.

METHODS

We constructed 63 combinations of the six criteria from the operational definition of IEDs, recently issued in the EEG-glossary of the International Federation of Clinical Neurophysiology (IFCN). The diagnostic gold standard was derived from video-EEG recordings. In a testing EEG dataset from 100 patients, we selected the best performing combinations of criteria and then we validated them in an independent dataset from 70 patients. We compared their performance with subjective, expert-scorings and we determined inter-rater agreement (IRA).

RESULTS

Without using criteria, the specificity of expert-scorings was lower than the pre-defined threshold (86%). The best performing combination of criteria was the following: waves with spiky morphology, followed by a slow-afterwave and voltage map suggesting a source in the brain. In the validation dataset this achieved a specificity of 97% and a sensitivity of 89%. IRA was substantial.

CONCLUSIONS

The optimized set of criteria for defining IEDs has high accuracy and IRA.

SIGNIFICANCE

Using these criteria will contribute to decreasing over-reading of EEG and avoid misdiagnosis of epilepsy.

Criteria for defining interictal epileptiform discharges in EEG: A clinical validation study

Objective

To define and validate criteria for accurate identification of EEG interictal epileptiform discharges (IEDs) using (1) the 6 sensor space criteria proposed by the International Federation of Clinical Neurophysiology (IFCN) and (2) a novel source space method. Criteria yielding high specificity are needed because EEG over-reading is a common cause of epilepsy misdiagnosis.

Methods

Seven raters reviewed EEG sharp transients from 100 patients with and without epilepsy (diagnosed definitively by video-EEG recording of habitual events). Raters reviewed the transients, randomized, and classified them as epileptiform or nonepileptiform in 3 separate rounds: in 2, EEG was reviewed in sensor space (scoring the presence/absence of each IFCN criterion for each transient or classifying unrestricted by criteria [expert scoring]); in the other, review and classification were performed in source space.

Results

Cutoff values of 4 and 5 criteria in sensor space and analysis in source space provided high accuracy (91%, 88%, and 90%, respectively), similar to expert scoring (92%). Two methods had specificity exceeding the desired threshold of 95%: using 5 IFCN criteria as cutoff and analysis in source space (both 95.65%); the sensitivity of these methods was 81.48% and 85.19%, respectively.

Conclusions

The presence of 5 IFCN criteria in sensor space and analysis in source space are optimal for clinical implementation. By extracting these objective features, diagnostic accuracy similar to expert scorings is achieved.

Classification of evidence

This study provides Class III evidence that IFCN criteria in sensor space and analysis in source space have high specificity (>95%) and sensitivity (81%–85%) for identification of IEDs.

Multimodal localization and surgery for epileptic spasms of focal origin: a review

Epileptic spasms (ES) are a common manifestation of intractable epilepsy in early life and can lead to devastating neurodevelopmental consequences. Epilepsy surgery for ES is challenging because of inherent difficulties in localizing the epileptogenic zone in affected infants and children. However, recent clinical series of resective neurosurgery for ES suggest that not only is surgery a viable option for appropriately selected patients, but postoperative seizure outcomes can be similar to those achieved in other types of focal epilepsy. Increased awareness of ES as a potentially focal epilepsy, along with advances in neuroimaging and invasive monitoring technologies, have led to the ability to surgically treat many patients with ES who were previously not considered surgical candidates. In this study, the authors review the current state of epilepsy surgery for ES. Specifically, they address how advances in neuroimaging and invasive monitoring have facilitated patient selection, presurgical evaluation, and ultimately, resection planning.

The Diagnostic Accuracy of Video Electroencephalography Without Event Capture

OBJECTIVE

The aim of this study was to quantify the accuracy of 24-hour video electroencephalography (vEEG) for the diagnosis of epilepsy when a patient's typical paroxysmal event was not captured (no-event vEEG).

METHODS

We performed a retrospective chart review of all first-time 24 hour no-event vEEG studies at Cincinnati Children's Hospital Medical Center. Clinician diagnosis of epilepsy with a minimum of one year follow-up was used as the reference standard to calculate diagnostic accuracy. Sensitivity and specificity of routine EEG (rEEG) and vEEG were compared in patients with both studies, and factors affecting the accuracy of vEEG were explored with a multivariable analysis.

RESULTS

No-event vEEG showed sensitivity of 0.54 (95% confidence interval [CI] 0.44 to 0.64) and specificity of 0.88 (95% CI 0.84 to 0.92) respectively, with a diagnostic odds ratio of 7.53 (95% CI 4.45 to 12.76). The sensitivity of vEEG was statistically superior to that of rEEG, whereas specificity was comparable. Age emerged as the only factor that affected the diagnostic accuracy of no-event vEEG.

CONCLUSION

Even in the absence of a typical seizure or spell, video EEG is a useful test for predicting or excluding epilepsy, with diagnostic accuracy that is superior to rEEG and unaffected by the presence of a chronic neurological condition.

Effective withdrawal of antiepileptic drugs in premonitoring admission to capture seizures during limited video-EEG monitoring

Objective

Withdrawal of antiepileptic drugs (AEDs) is commonly applied to capture seizures in video‐EEG (vEEG) monitoring for patients with infrequent but intractable seizures. Because of the half‐life of AEDs, AED withdrawal during only vEEG tends to be inadequate to provoke seizures within the vEEG admission. We hypothesize that prewithdrawal of long‐half‐life AEDs in premonitoring admission (PMA) is safe and effective to capture seizures in the limited time of vEEG. We determined the effect of half‐life on the interval between AED withdrawal and seizure occurrence.

Methods

We collected 87 patients with three criteria: (1) seizure occurrence ≤3 per month; (2) AEDs ≥2; (3) AED withdrawal during their admission, among 126 consecutive patients who underwent vEEG in the Department of Neurosurgery, Hiroshima University Hospital between 2011 and 2014. We divided patients into two groups on the basis of half‐life of AED: Group A (23 patients) with phenobarbital (PB) and/or zonisamide (ZNS); Group B (64 patients) with other AEDs. In Group A, PB and ZNS were withdrawn during 4‐day PMA before vEEG started. Further AED withdrawal was performed during vEEG, depending on the seizure occurrence.

Results

The number of AEDs on admission was significantly higher in Group A (2–6, 3.5 ± 0.9; range, mean ±SD) than in Group B (2–5, 2.8 ± 0.8) (p < 0.01). All 23 Group A patients and 13 (20%) Group B patients underwent AED withdrawal during PMA. Seizures occurred during PMA in two patients in both Group A (9%) and Group B (15%). The first seizure occurred significantly longer after the start of withdrawal in Group A (6.1 ± 2.0 days) than in Group B (2.8 ± 1.3 days) (p < 0.01). Seizures were equally captured between both groups: 96% in Group A and 92% in Group B during vEEG.

Significance

For epilepsy patients who are treated with PB and/or ZNS, we recommend the planning of AED withdrawal during PMA before the start of vEEG to succeed in capturing seizures during the limited time of vEEG monitoring.

Paroxysmal nonepileptic events in children with epilepsy

OBJECTIVE

The aim of this study was to clarify the characteristics of paroxysmal nonepileptic events (PNEs) suspected as being epileptic seizures by families of children with epilepsy.

METHODS

The video-EEG (vEEG) recordings of habitual paroxysmal events in children with epilepsy at Nagoya University Hospital between October 2006 and January 2016 were reviewed. Based on the doctor's suspicion before the vEEG, the PNEs were divided into two groups that included PNEs suspected as epileptic seizures and PNEs suspected as PNEs. PNEs in the former group were classified based on the suspected seizure type.

RESULTS

Of 886 habitual paroxysmal events, vEEG confirmed that 83 events (68 children) were PNEs. The median age of the 68 children was 3.2 years. Concurrent epilepsies included focal epilepsies (n=33), infantile spasms (n=16), and other types (n=19). The most common types of PNEs were sleep myoclonus (n=11), followed by stereotypies (n=9), awake myoclonus (n=8), paroxysmal ocular deviations (PODs, n=8), and tonic posturing (n=8). Even after direct observation or video viewing, the doctors suspected epileptic seizures in all three of the PODs and two of the tonic posturing children. Before the vEEG, however, the accurate visual information led to the speculation that the four psychogenic and two sleep myoclonus events were all PNEs. Myoclonus, stereotypies, and head drops were often misdiagnosed as epileptic spasms, while PODs and tonic posturing were often misdiagnosed as focal seizures with motor components. Additionally, staring and motion arrest during a drowsy state were often misdiagnosed as focal dyscognitive seizures. Seven of eight patients with PODs had epileptic spasms that were concurrent with epileptic seizures. A diffuse cerebral lesion or reduced visual acuity was seen in seven patients with PODs.

CONCLUSION

We re-emphasize that vEEG is essential for accurate diagnosis and provides evidence for listing POD in the differential diagnosis of oculomotor paroxysmal events.

The Concept of Effective Inflow: Application to Interictal Localization of the Epileptogenic Focus From iEEG

GOAL

Accurate determination of the epileptogenic focus is of paramount diagnostic and therapeutic importance in epilepsy. The current gold standard for focus localization is from ictal (seizure) onset and thus requires the occurrence and recording of multiple typical seizures of a patient. Localization of the focus from seizure-free (interictal) periods remains a challenging problem, especially in the absence of interictal epileptiform activity.

METHODS

By exploring the concept of effective inflow, we developed a focus localization algorithm (FLA) based on directed connectivity between brain sites. Subsequently, using the measure of generalized partial directed coherence over a broad frequency band in FLA for the analysis of interictal periods from long-term (days) intracranial electroencephalographic signals, we identified the brain region that is the most frequent receiver of maximal effective inflow from other brain regions.

RESULTS

In six out of nine patients with temporal lobe epilepsy, the thus identified brain region was a statistically significant outlier (p < 0.01) and coincided with the clinically assessed epileptogenic focus. In the remaining three patients, the clinically assessed focus still exhibited the highest inflow, but it was not deemed an outlier (p > 0.01).

CONCLUSIONS

These findings suggest that the epileptogenic focus is a region of intense influence from other regions interictally, possibly as a mechanism to keep it under control in seizure-free periods.

SIGNIFICANCE

The developed framework is expected to assist with the accurate epileptogenic focus localization, reduce hospital stay and healthcare cost, and provide guidance to treatment of epilepsy via resective surgery or neuromodulation.

The yield of video-EEG telemetry evaluation for non-surgical candidate children

BACKGROUND

Video EEG (VEEG) is performed for most pediatric patients in order to evaluate unclear paroxysmal events and improve our understanding of difficult to control epileptic patients.

PURPOSE

To characterize the video EEG studies on children who are not candidates for surgery in order to identify the parameters that affect results in level of improving the rate of acquisition, as well as improving the ability to expect the likelihood of epilepsy and of gathering new information as a result of the VEEG.

METHODS

Retrospective chart analysis of all consecutive patients who underwent VEEG in two VEEG monitoring units.

RESULTS

323 children of a mean age of 7 years (STD 4.73, range 0-17 years) were monitored for a mean duration of 2 days (STD 1.65, range 1-10 days). The main reasons for monitoring were: evaluation of unclear events (n = 234), evaluation of previously diagnosed epilepsy (n = 36) and confirmation of Electrical Status Epilepticus in Sleep (ESES) (n = 34). The main event types for evaluation were: staring episodes (n = 67), myoclonic jerks (n = 35) and abnormal eye movement (n = 22). Suspected events were captured in 70% of the patients. There was a positive correlation between acquisition of suspected events and each of the following: duration of the monitoring, the frequency of investigated events per history, the type of investigated events. A prior interictal epileptic activity on routine EEG was a positive predictor of an event to be epileptic (p = 0.003). Amongst the group of known epileptic patients, VEEG had role in changing diagnosis in 53% of patients. Many of them had focal interictal epileptiform activity in their routine EEG.

CONCLUSIONS

Selecting patients with frequent events and longer monitoring periods increase the yield of VEEG. Looking carefully into clinical characteristics of the patient prior to VEEG can clarify diagnosis therefore render the VEEG test superfluous to subgroups of patients. Prior routine epileptic EEG, coexistence of other seizure types, behaviors accompanying the investigated habitual behavior and abnormalities in other investigations (MRI, cognitive function and EEG) are the parameters that can predict diagnosis of epilepsy. Precise diagnosis in known epileptic patients as a result of VEEG is more likely for those with focal interictal epileptiform discharges in routine EEG.

Predictors of Length of Stay in Children Admitted for Presurgical Evaluation for Epilepsy Surgery

RATIONALE

One challenge for families whose children are undergoing presurgical evaluation for epilepsy surgery is the unpredictable length of hospitalization for video-electroencephalograph monitoring. The goal of this study was to retrospectively evaluate length of stay in children admitted for presurgical evaluation at a tertiary referral center.

METHODS

Duration of stay for children with medically intractable epilepsy admitted for presurgical evaluation to the Pediatric Epilepsy Monitoring Unit at Mayo Clinic Rochester between 2010 and 2013 was evaluated retrospectively.

RESULTS

Of 140 children, surgical candidacy was determined in 122 (87.1%) (72 candidates, 50 noncandidates). The mean length of stay was 4.0 ± 3.7 days and was not predicted by candidacy for surgery, age at monitoring, duration of epilepsy, number of antiepileptic drugs at admission, or focal/hemispheric magnetic resonance imaging abnormality. Shorter length of stay was predicted by younger age at epilepsy onset (P < 0.05) and shorter interval since most recent seizure (P = 0.001). Subtraction ictal single-photon emission computed tomography coregistered to magnetic resonance imaging was performed in 43 (35.2%) children, and correlated with longer length of stay (mean 5.1 ± 4.1 days for subtraction ictal single-photon emission computed tomography coregistered to magnetic resonance imaging users versus 3.5 ± 3.3 days for nonusers, P = 0.022). Antiepileptic drugs were reduced either upon or after admission in 67 (54.9%) children, and the length of stay was significantly longer in these patients (mean 5.5 ± 4.1 days if antiepileptic drugs were reduced versus 2.2 ± 2.1 days if not reduced, P < 0.001).

CONCLUSIONS

Significant predictors of shorter length of stay include younger age at epilepsy onset, shorter interval from most recent seizure, lack of subtraction ictal single-photon emission computed tomography coregistered to magnetic resonance imaging, and lack of need for AED reduction on or after admission.

Paroxysmal nonepileptic events in pediatric patients

OBJECTIVES

Paroxysmal nonepileptic events (PNEs) are frequently encountered phenomena in children. Although frequencies and types of PNEs have been extensively studied in adult populations, the data available for children and adolescents are limited, especially in patients without underlying neurologic disorders. In this study, we evaluated and compared the characteristics of PNEs between age groups and according to the presence of neurologic deficits to improve early detection and diagnosis of PNEs.

METHODS

We retrospectively reviewed 887 pediatric patients who were admitted to the epilepsy monitoring unit at the Samsung Medical Center between December 2001 and July 2014. One hundred and forty-one patients (15.9%) were diagnosed as having PNEs on the basis of their clinical history and long-term video-electroencephalography (EEG) monitoring (VEM).

RESULTS

Children with PNEs were divided into three groups by age: 1) the infant, toddler, and preschool group (<6 years, N=50, 35.5%); 2) the school-age group (6-<12 years, N=30, 21.3%); and 3) the adolescent group (12-<18 years, N=61, 43.3%). Physiologic disorders, such as normal infant behavior, sleep movement, and staring, were more common in patients younger than 6 years of age, whereas psychogenic nonepileptic seizures were predominant in patients older than 6 years. Vasogenic syncope was also frequently observed in the adolescent group and was confirmed by the head-up tilt test. There was no significant difference in specific PNE types between the groups of patients with or without neurologic deficits.

CONCLUSIONS

Physiologic symptoms were predominant in the younger age group, whereas psychogenic nonepileptic seizures were observed in older age groups more often. Clinical pattern recognition by age plays an important role in clinical practice, because pediatric patients present various types of PNEs with age-specific patterns. Considering various and inconsistent presentations and the importance of correct diagnosis, long-term VEM can be helpful in diagnosing normal infant behavior and psychogenic nonepileptic seizures.

Long-term EEG in children

Long-term video-EEG corresponds to a recording ranging from 1 to 24 h or even longer. It is indicated in the following situations: diagnosis of epileptic syndromes or unclassified epilepsy, pre-surgical evaluation for drug-resistant epilepsy, follow-up of epilepsy or in cases of paroxysmal symptoms whose etiology remains uncertain. There are some specificities related to paediatric care: a dedicated pediatric unit; continuous monitoring covering at least a full 24-hour period, especially in the context of pre-surgical evaluation; the requirement of presence by the parents, technician or nurse; and stronger attachment of electrodes (cup electrodes), the number of which is adapted to the age of the child. The chosen duration of the monitoring also depends on the frequency of seizures or paroxysmal events. The polygraphy must be adapted to the type and topography of movements. It is essential to have at least an electrocardiography (ECG) channel, respiratory sensor and electromyography (EMG) on both deltoids. There is no age limit for performing long-term video-EEG even in newborns and infants; nevertheless because of scalp fragility, strict surveillance of the baby's skin condition is required. In the specific context of pre-surgical evaluation, long-term video-EEG must record all types of seizures observed in the child. This monitoring is essential in order to develop hypotheses regarding the seizure onset zone, based on electroclinical correlations, which should be adapted to the child's age and the psychomotor development.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Seizure control following palliative resective surgery for intractable epilepsy-a pilot study

BACKGROUND

Patients with intractable epilepsy who have bilateral epileptic foci may not qualify for curative epilepsy surgery. In some cases palliative resection may be undertaken with a goal to decrease seizure frequency and improve quality of life. Here we present data on the outcome of palliative epilepsy surgery in children.

METHODS

We reviewed medical charts of children who underwent palliative resection for intractable epilepsy during the years 1999-2013 at Children's Hospital of Michigan. The palliative intent of resection was declared preoperatively. Outcome was assessed in terms of seizure reduction.

RESULTS

There were 18 patients (11 males, median age of surgery was 3.5 years [range 0.5-16 years]). The median duration of follow-up after surgery was 12.5 months (range 6-60 months). Hemispherectomy was the most commonly performed palliative resection (nine patients), followed by lobectomy (six patients), multilobar resection (one patient), and tuberectomy (two patients). Reduction in seizure frequency was observed in 11 patients, with eight patients achieving seizure freedom on antiepileptic drugs and three with >50% reduction in seizure frequency. Transient improvement in seizure frequency occurred in two patients, whereas there was no benefit in five patients.

CONCLUSIONS

Beneficial effects of epilepsy surgery may be realized in carefully selected situations wherein the most epileptogenic focus is resected to reduce seizure burden and improve quality of life.

Predictors of recording an event during prolonged inpatient video electroencephalogram monitoring in children

BACKGROUND

Distinguishing between seizures and nonepileptic events is a key challenge in pediatric neurology. The diagnostic gold standard is prolonged inpatient video electroencephalogram monitoring. However, little is known about preadmission characteristics that are predictive of recording an event during such monitoring.

METHODS

This is a retrospective chart review of children undergoing prolonged inpatient video electroencephalogram monitoring between 2009 and 2012 at a tertiary referral center for the purpose of distinguishing between seizures and nonepileptic events. Demographic information, medical history, event characteristics, and inpatient monitoring course were abstracted.

RESULTS

Two-hundred thirteen children were identified. The median recording duration was 25 hours (interquartile range 22.4-48.5), and median time to event of interest (among those with an event recorded) was 4.5 hours (interquartile range 1.4-18.8). An event of interest was recorded in 66% of patients. At the event level, 20% of recorded events were associated with an electroencephalogram correlate, which refers to a change in the pattern seen on the electroencephalogram during a seizure. At the patient level, 112 (79.4%) with events recorded had only nonepileptic events recorded, 25 (17.7%) had only seizures recorded, and 4 (2.8%) had both recorded. Recording an event was predicted by the presence of intellectual disability (P = 0.001), greater preadmission event frequency (P < 0.001), and shorter latency since most recent event (P < 0.001).

CONCLUSIONS

Prolonged inpatient electroencephalogram monitoring captured an event of interest in two-thirds of patients, with most of these events captured within less than four and a half hours of recording onset. Several factors predict a greater yield with prolonged inpatient video electroencephalogram monitoring--including event frequency, latency since the most recent event, and the presence of intellectual disability--and can be used to counsel patients regarding this study for the purpose of event capture in the context of shared decision making.

Children with psychogenic non-epileptic seizures (PNES): a detailed semiologic analysis and modified new classification

PURPOSE

To analyze children with psychogenic non epileptic seizures and propose a modified new classification.

METHODS

This retrospective analysis included 56 children aged <18 years (M:F=26:30; mean age: 12.3±4.0 years) diagnosed PNES on video-EEG monitoring. The semiological characteristics like pattern of bodily movements, emotional signs, stereotypy, ictal vocalization, responsiveness, delay in diagnosis etc. were recorded. We analyzed our data as per previous adult classifications and proposed a modified classification.

RESULTS

There were 190 recorded attacks (range: 1-9, median: 3) recorded. The age at onset of PNES was 8.9±4.1 years (range: 0.4-15.8 years; median: 9 years), age at diagnosis: 11.9±4.1 years (range: 2-17; median: 12.0 years), delay in diagnosis: 3.2±3.7 years (range: 0-15; median: 2.0 years). Anxiety disorder was seen in 9 (16.1%), stress in 6 (10.7%) children. Flexion/extension bodily movements were seen in 40 (70.1%), negative emotional signs in 17 (30.4%) and tremors in 14 (25%) cases. Thirty-three (58.9%) patients diagnosed as having true seizures initially and were on anti-epileptic drugs (AEDs), 14 patients (25.0%) initially diagnosed of PNES which remained unchanged after VEEG, nine patients (16.1%) had both PNES and true seizures. Twenty-six (46.4%) of our patients into the existing classifications. We then classified our patients into categories of a modified new classification: Hypermotor: 13 (23.2%), partial motor: 8 (14.3%), affective/emotional behaviour phenomena: 2 (3.6%), dialeptic: 8 (14.3%), 'aura': 3 (5.4%), mixed: 22 (39.3%).

CONCLUSION

Incorrect diagnosis of epilepsy leads to unnecessary drug treatment. A detailed analysis of semiology and classification helps in early diagnosis of PNES. A modified systematic classification of PNES is proposed which would help in better standardization of PNES.

Is rapid withdrawal of anti-epileptic drug therapy during video EEG monitoring safe and efficacious?

PURPOSE

Video electroencephalographic monitoring (VEM) is used to record ictal and interictal epileptiform activity and to ascertain the level of concordance between the two. Often, taper or discontinuation of anti-epileptic (AED) therapy is needed to facilitate seizure occurrence. The safety of this practice is unclear and long-term sequelae have yet to be elucidated.

METHODS

This is a prospective study of 158 patients subjected to combined sleep-deprived VEM with rapid AED withdrawal, for evaluation of seizure-like episodes over 24 months under the care of an epileptologist with direct nursing observation and EEG technician support in our telemetry unit. In most cases, AEDs were discontinued within 24h of admission. We assessed the diagnostic yield and safety of VEM as well as epilepsy surgery outcomes.

RESULTS

VEM answered the study question in 90.5% of cases but failed to record ictal events in 9.5%. This diagnostic yield was achieved over a mean VEM duration of 4.53±1.44 days, with no benefit of longer monitoring. These findings improved quality of life by optimizing medical and surgical therapeutic planning, leading to improved seizure control. Overall, 32.9% of the cohort received epilepsy surgery. The complication rate was 5.06%, characterized largely by musculoskeletal pain secondary to clinical seizure activity, with no mortality observed. In the first month following VEM 2.5% of patients received emergency-room admission for seizure clustering.

CONCLUSIONS

VEM with combined sleep deprivation and protocolized rapid AED withdrawal is a safe and effective investigative technique with no adverse long-term sequelae. It is a reliable strategy for therapeutic planning and can be used to determine candidacy for surgical treatment.

How to establish causality in epilepsy surgery

Focality in electro-clinical or neuroimaging data often motivates epileptologists to consider epilepsy surgery in patients with medically-uncontrolled seizures, while not all focal findings are causally associated with the generation of epileptic seizures. With the help of Hill's criteria, we have discussed how to establish causality in the context of the presurgical evaluation of epilepsy. The strengths of EEG include the ability to determine the temporal relationship between cerebral activities and clinical events; thus, scalp video-EEG is necessary in the evaluation of the majority of surgical candidates. The presence of associated ictal discharges can confirm the epileptic nature of a particular spell and whether an observed neuroimaging abnormality is causally associated with the epileptic seizure. Conversely, one should be aware that scalp EEG has a limited spatial resolution and sometimes exhibits propagated epileptiform discharges more predominantly than in situ discharges generated at the seizure-onset zone. Intraoperative or extraoperative electrocorticography (ECoG) is utilized when noninvasive presurgical evaluation, including anatomical and functional neuroimaging, fails to determine the margin between the presumed epileptogenic zone and eloquent cortex. Retrospective as well as prospective studies have reported that complete resection of the seizure-onset zone on ECoG was associated with a better seizure outcome, but not all patients became seizure-free following such resective surgery. Some retrospective studies suggested that resection of sites showing high-frequency oscillations (HFOs) at >80Hz on interictal or ictal ECoG was associated with a better seizure outcome. Others reported that functionally-important areas may generate HFOs of a physiological nature during rest as well as sensorimotor and cognitive tasks. Resection of sites showing task-related augmentation of HFOs has been reported to indeed result in functional loss following surgery. Thus, some but not all sites showing interictal HFOs are causally associated with seizure generation. Furthermore, evidence suggests that some task-related HFOs can be transiently suppressed by the prior occurrence of interictal spikes. The significance of interictal HFOs should be assessed by taking into account the eloquent cortex, seizure-onset zone, and cortical lesions. Video-EEG and ECoG generally provide useful but still limited information to establish causality in presurgical evaluation. A comprehensive assessment of data derived from multiple modalities is ultimately required for successful management.

Clinical and ictal characteristics of infantile seizures: EEG correlation via long-term video EEG monitoring

PURPOSE

The semiology of infantile seizures often shows different characteristics from that of adults. We performed this study to describe clinical and ictal characteristics of infantile seizures at less than two years of age.

METHODS

A retrospective study was done for infants with epilepsy (ages: 1-24months) who underwent long-term video electroencephalography (EEG) monitoring at Samsung medical center between November 1994 and February 2012. We analyzed the clinical and ictal characteristics of the 56 cases from 51 patients.

RESULTS

In 69% of the patients, the seizure onset was before six months of age and the etiology was symptomatic in one third of the patients. Twelve seizure types were identified; spasms (24%), unilateral motor seizures (18%), and generalized tonic seizures (15%) were the three frequent types of seizure. All partial seizures were well correlated with the partial-onset ictal EEG, however 19.4% (7/36) of clinically generalized seizures revealed partial-onset ictal EEG. About one-thirds (4/11) of generalized tonic seizures had its ictal onset on unilateral or bilateral frontal areas and two out of seven generalized myoclonic seizures showed unilateral frontal rhythmic activities. Hypomotor seizures mainly arose from the temporal areas and hypermotor seizures from the frontal regions.

CONCLUSIONS

Even though most of the seizure semiology of infants is well correlated with ictal EEG, some of the generalized tonic seizures or myoclonic seizures revealed partial-onset ictal EEG suggesting localized epileptic focus. Accurate definition of seizures via video EEG monitoring is necessary for proper management of seizures in infancy, especially in some clinically generalized seizures.

Predictors of seizure occurrence in children undergoing pre-surgical monitoring

PURPOSE

Long-Term-Monitoring (LTM) is a valuable tool for seizure localization/lateralization among children with refractory-epilepsy undergoing pre-surgical-monitoring. The aim of this study was to examine the factors predicting occurrence of single/multiple seizures in children undergoing pre-surgical monitoring in the LTM unit.

METHODS

Chart review was done on 95 consecutive admissions on 92 children (40 females) admitted to the LTM-unit for pre-surgical workup. Relationship between occurrence of multiple (≥ 3) seizures and factors such as home seizure-frequency, demographics, MRI-lesions/seizure-type and localization/AED usage/neurological-exam/epilepsy-duration was evaluated by logistic-regression and survival-analysis. Home seizure-frequency was further categorized into low (up-to 1/month), medium (up-to 1/week) and high (>1/week) and relationship of these categories to the occurrence of multiple seizures was evaluated. Mean length of stay was 5.24 days in all 3 groups.

RESULTS

Home seizure frequency was the only factor predicting the occurrence of single/multiple seizures in children undergoing presurgical workup. Other factors (age/sex/MRI-lesions/seizure-type and localization/AED-usage/neurological-exam/epilepsy-duration) did not affect occurrence of single/multiple seizures or time-to-occurrence of first/second seizure. Analysis of the home-seizure frequency categories revealed that 98% admissions in high-frequency, 94% in the medium, and 77% in low-frequency group had at-least 1 seizure recorded during the monitoring. Odds of first-seizure increased in high vs. low-frequency group (p=0.01). Eighty-nine percent admissions in high-frequency, 78% in medium frequency, versus 50% in low-frequency group had ≥ 3 seizures. The odds of having ≥ 3 seizures increased in high-frequency (p=0.0005) and in medium-frequency (p=0.007), compared to low-frequency group. Mean time-to-first-seizure was 2.7 days in low-frequency, 2.1 days in medium, and 2 days in high-frequency group. Time-to-first-seizure in high and medium-frequency was less than in low-frequency group (p<0.0014 and p=0.038).

CONCLUSION

Majority of the admissions (92%) admitted to the LTM-unit for pre-surgical workup had at-least one seizure during a mean length of stay of 5.24 days. Home seizure-frequency was the only predictor influencing occurrence of single/multiple seizures in the LTM unit. Patients with low seizure-frequency are at risk for completing the monitoring with less than the optimum number (<3) of seizures captured.

Utility and safety of prolonged video-EEG monitoring in a tertiary pediatric epilepsy monitoring unit

Prolonged video-EEG (vEEG) monitoring helps characterize paroxysmal events and epilepsy. There is limited literature in pediatrics describing the safety and utility of vEEG. We retrospectively reviewed 454 pediatric epilepsy monitoring unit admissions over two years. Final event diagnoses, duration of seizures, and medical complications were analyzed. Two hundred twenty admissions (48.4%) captured epileptic seizures, 150 (33.0%) captured nonepileptic events, and 84 (18.5%) failed to capture any events. Medical complications were seen in 4 patients (1.8%) with no long-term complications. Seventeen episodes of status epilepticus occurred in 13 patients. This constituted 2.9% of all admissions and 5.9% of admissions with epileptic seizures. The median duration of status was 26 min, and three patients required transfer to the pediatric intensive care unit. Video-EEG monitoring had a high yield in capturing events and differentiating epileptic from nonepileptic events. Our pediatric patients experienced greater risk of status epilepticus but lesser risk of injury.

Prevalence of epileptic and nonepileptic events after pediatric traumatic brain injury

Though posttraumatic epilepsy (PTE) is a prominent sequela of traumatic brain injury (TBI), other nonepileptic phenomena also warrant consideration. Within two UCLA pediatric TBI cohorts, we categorized five spell types: 1) PTE; 2) Epilepsy with other potential etiologies (cortical dysplasia, primary generalized); 3) Psychopathology; 4) Behavior misinterpreted as seizures; and 5) Other neurologic events. The two cohort subsets differed slightly in injury severity, but they were otherwise similar. Overall, PTE occurred in 40%, other epilepsy etiologies in 14%, and nonepileptic spells collectively in 46%. Among children with spells, PTE was associated with severe TBI (p=0.001), whereas psychopathology (p=0.014) and epilepsy with other etiologies (p=0.006) were associated with milder TBI severity. Posttraumatic epilepsy (p=0.002) and misinterpreted behavior (p=0.049) occurred with younger injury age. Psychopathology (p=0.020) and other neurologic events (p=0.002) occurred with older injury age. In evaluating possible PTE, clinicians should maintain a broad differential diagnosis to prevent misdiagnosis and inappropriate treatment.

Childhood paroxysmal nonepileptic events

We aimed to determine the types and clinical characteristics of paroxysmal nonepileptic events (PNEs) in children. During a 13-year period, 765 patients underwent long-term video-EEG monitoring, and 95 (12.4%) of them were identified to have PNEs. The most common diagnoses were conversion disorder, parasomnias, staring spells, movement disorders, and hypnic jerks. Paroxysmal nonepileptic events originated from physiologic or organic (43.2%) and psychogenic (56.8%) causes. Mean delay in diagnosis was 3.1 years. Mean ages at diagnosis were 8.8 and 13.8 years in physiologic or organic and psychogenic groups, respectively. A marked female predominance was seen in the psychogenic group, whereas males slightly predominated in the physiologic or organic group. In the physiologic or organic group, events were less frequent, longer in duration, and commonly manifested as subtle motor activity, whereas subtle and prominent motor activities were encountered equally in both groups. Concomitant epilepsy was present in 10.5% of the patients. Differences in clinical characteristics may be helpful in differentiating physiologic or organic PNEs in children from psychogenic PNEs.

Paroxysmal nonepileptic events in pediatric patients confirmed by long-term video-EEG monitoring--Single tertiary center review of 143 patients

The purpose of the study was to evaluate the clinical characteristics of paroxysmal nonepileptic events (PNEs) in pediatric patients. Reports of 1108 patients who underwent long-term video-EEG monitoring at Seoul National University Children's Hospital were reviewed retrospectively. One hundred forty-three (12.9%) patients were diagnosed as having PNEs. The most common type of PNE was staring. Staring, tonic posturing, sleep myoclonus, and sleep-related disorders were more common in patients younger than 6 years old. Psychogenic nonepileptic seizure was the most common PNE in patients older than 6 years. Patients who were younger than 6 years old showed shorter disease duration and more varied types of PNEs when compared to older patients (6 years old or older). Presence of epilepsy was not significantly related to clinical difference in PNEs. In patients with developmental delay, staring and tonic posture were significantly more frequent than patients without developmental delay. Thirty-two patients without concurrent epilepsy were misdiagnosed with epilepsy, and AEDs were discontinued after the correct diagnosis of PNEs. Whenever the diagnosis of paroxysmal abnormal behavior is uncertain, correct diagnosis should be made using long-term video-EEG monitoring, especially in younger pediatric patients and patients with developmental delay.

Usefulness of Video-EEG monitoring in patients with drug-resistant epilepsy

OBJECTIVE

To evaluate the characteristics of patients on whom long-term Video-EEG monitoring is performed in a specialist centre and to assess its suitability to study refractory epilepsy patients.

METHODS

A prospective analysis and study of Video-EEG monitoring was performed in a series of 100 refractory epilepsy patients from a single centre. The analysis included demographic data, the time until the first seizure, the methods used to provoke seizures, and the outcome (usefulness, change in the management, pharmacological and surgical improvement). A subgroup analysis based on diagnosis was performed.

RESULTS

The study was performed mainly on young people (mean 34.4 years) and the first seizure appeared in a mean of 30hours, requiring most of the patients to withdraw the medication. Nevertheless, there were no cases of status epilepticus. The usefulness of the test was high in all the groups. The management was changed in 65% of the patients with pharmacological and surgical improvement.

CONCLUSION

Long-term Video-EEG monitoring is a suitable test to study refractory epilepsy patients. The main problem in our country is accesibility.

Recognition of child abuse in the epilepsy monitoring unit

Despite being underreported and underrecognized, child maltreatment is one of the most common causes of childhood morbidity and mortality. The epilepsy monitoring unit is especially amenable for identification of those at risk because it involves direct observation of behavior for days at a time. Although nonepileptic events may suggest psychosocial etiologies, we describe a case where the diagnosis of child maltreatment was made when no habitual events were recorded in the epilepsy monitoring unit.

Nonepileptic paroxysmal events in a pediatric population

Nonepileptic paroxysmal events in children are common, and may be more diverse in etiology than those seen in adults. We determined the types of nonepileptic events that are most prominent in the pediatric population, and stratified those events by age group. Ninety-four of 416 pediatric patients monitored during a 3-year period (23%) were found to have had nonepileptic events. Thirty-eight percent of these children were diagnosed with psychogenic nonepileptic seizures, and 72% of those were adolescents. In children younger than 5 years of age, behavioral events and parasomnias were the most common mimickers of epilepsy. Other events, including stereotyped movements and myoclonus, were also diagnosed. We suggest that children with refractory paroxysmal events should be considered for early inpatient monitoring.

Safety and yield of early cessation of AEDs in video-EEG telemetry and outcomes

BACKGROUND

Video-electroencephalography (VEEG) telemetry is the simultaneous recording of ictal and interictal EEG pattern and paroxysmal behavior to investigate the nature of paroxysmal events.

METHODS

This is a prospective study performed to asses the safety and yield of early discontinuation of antiepileptic drugs (AEDs) in the telemetry unit. Over a 2.5-year period, 50 patients that met the indications for VEEG monitoring were admitted by an epileptologist to neuro-observation units with continuous monitoring, nursing coverage and EEG technicians support during working hours and on-call thereafter. In most cases AEDs (except Phenobarbital) were discontinued in 24h. We prospectively assessed the yield and safety of the telemetry investigation as well as epilepsy surgery outcomes.

RESULTS

Our monitoring answered the study question in 88% of the patients. The question was not answered in 12% of cases due to the lack of recorded events. Our results changed the management in 74% of cases and potentially improved quality of life by decreasing the AEDs consumption and number of seizures per month. Over all, 22% received epilepsy surgery and became either seizure free or their seizures became non-disabling. Our method significantly decreased the duration of hospital admission for monitoring and minimal complications occurred only in 8% of patients.

CONCLUSIONS

In conclusion, our method for short VEEG monitoring has a high yield for diagnosis, minimal complications and is cost effective. These qualities, together with good surgery results validate our method for the investigation and treatment of refractory seizure cases.

A prospective study on the cost-effective utilization of long-term inpatient video-EEG monitoring in a developing country

To investigate diagnostic value, therapeutic benefit and cost-effective utilization of video-EEG monitoring (VEM) in a comprehensive epilepsy program in a developing country. The authors prospectively recruited all patients who underwent long-term (> or =3 hours) inpatient VEM during a 10-month period. The cohort was followed to gather information about the proportion of patients in whom long-term management was altered by VEM and resultant impact on direct health care costs. Out of 143 study subjects (median age 22 years), 102 (71.3%) were referred for presurgical evaluation. The median duration of VEM was 61 hours, and median number of events recorded per patient was 3. Video-EEG monitoring helped to clarify the epilepsy syndromic diagnosis in 123 of 132 (93.2%) patients referred with the diagnosis of epileptic seizures. Video-EEG monitoring confirmed coexistent complex partial seizures in 4 of 11 (36.4%) patients with a referral diagnosis of psychogenic nonepileptic events. During mean follow-up period of 2.2 years, 48 patients (33.6%) underwent epilepsy surgery. A significant decrease in antiepileptic drug polytherapy, and minimization in recurring direct medical and nonmedical costs occurred. In addition to immediate diagnostic usefulness, VEM contributes significantly to long-term therapeutic and economic benefits for patients with difficult to diagnose and treat paroxysmal events.