The clinical utility of ambulatory EEG in childhood

Ambulatory EEG-video

Hospital based EEG recordings have been the norm to assist in the diagnosis and management of patients with unclassified events and known drug resistant epilepsy. Ambulatory EEG (AEEG) is a tool that comes to serve the needs for a portable testing that can be done at home, often with higher accessibility compared to an epilepsy monitoring unit and with lower cost. The current technology provides good quality EEG tracing and can be done with video when needed. In this review we discuss how AEEG should be performed and the preferred indications in which this test may be of utmost help. The advent of ultra-long ambulatory recording may be the future for selected patients as this technology evolves.

Continuous Spike-Waves during Slow Sleep Today: An Update

In the context of childhood epilepsy, the concept of continuous spike-waves during slow sleep (CSWS) includes several childhood-onset heterogeneous conditions that share electroencephalograms (EEGs) characterized by a high frequency of paroxysmal abnormalities during sleep, which have negative effects on the cognitive development and behavior of the child. These negative effects may have the characteristics of a clear regression or of a slowdown in development. Seizures are very often present, but not constantly. The above makes it clear why CSWS have been included in epileptic encephalopathies, in which, by definition, frequent EEG paroxysmal abnormalities have an unfavorable impact on cognitive functions, including socio-communicative skills, causing autistic features, even regardless of the presence of clinically overt seizures. Although several decades have passed since the original descriptions of the electroclinical condition of CSWS, there are still many areas that are little-known and deserve to be further studied, including the EEG diagnostic criteria, the most effective electrophysiological parameter for monitoring the role of the thalamus in CSWS pathogenesis, its long-term evolution, the nosographic location of Landau-Kleffner syndrome, standardized neuropsychological and behavioral assessments, and pharmacological and non-pharmacological therapies.

Proposed Pathway for the Utilization of Pediatric Ambulatory EEG

PURPOSE

The clinical utility of pediatric ambulatory-EEG (A-EEG) has been studied for decades, but limited information exists regarding which variables influence its utility. The authors aimed to evaluate clinical/EEG variables that may influence A-EEG yields and to develop a pathway for A-EEG utilization in children.

METHODS

Single-center retrospective review of A-EEGs performed from July 2019 to January 2021 in a tertiary referral center. The primary outcome was whether the A-EEG test successfully answered the referring physician's clinical question or influenced therapy. When it did, the A-EEG test was deemed useful. Clinical and EEG variables were assessed for their ability to predict utility. Further, the literature review generated 10 relevant prior studies whose details were used to generate a pathway for A-EEG utilization in children.

RESULTS

One hundred forty-two A-EEG studies were included (mean age 8.8 years, 48% male patients, mean A-EEG duration 33.5 hours). Overall, A-EEG was considered useful in 106 children (75%) but heavily influenced by A-EEG indication. Specifically, it was deemed useful for 94% of patients evaluated for electrical status epilepticus in slow-wave sleep, 92% of those evaluated for interictal/ictal burden, and 63% of those undergoing spell classification. The test indication (P < 0.001), a diagnosis of epilepsy (P = 0.02), and an abnormal routine EEG (P = 0.04) were associated with A-EEG test utility, although the multivariate analysis confirmed the test indication as the only independent outcome predictor of A-EEG.

CONCLUSIONS

Pediatric A-EEG is extremely useful for evaluating electrical status epilepticus in slow-wave sleep and interictal/ictal burden and is often helpful for spell classification. Among all clinical and EEG variables analyzed, the test indication was the only independent outcome predictor of obtaining a helpful A-EEG.

Video Ambulatory EEG in Children: A Quality Improvement Study

PURPOSE

We implemented a video ambulatory EEG (VA-EEG) Program as an alternative to inpatient video EEG monitoring for some patients given potential benefits related to quicker access, greater convenience, and lower cost. To evaluate the newly initiated program, we performed a quality improvement study to assess whether VA-EEG yielded studies with interpretable EEG and video quality that generated clinically beneficial data.

METHODS

This was a single-center prospective quality improvement study. We surveyed ordering clinicians, electroencephalographers, and caregivers regarding consecutive children who underwent clinically indicated VA-EEG. The primary outcome was the percentage of VA-EEG studies in which the ordering clinician reported that the study had answered the question of interest.

RESULTS

We evaluated 74 consecutive children selected to undergo clinically indicated VA-EEG by their clinicians and caregivers. Ordering clinicians reported that 77% of studies answered the question of interest. Electroencephalographers reported that the quality of the EEG and video was excellent or adequate in 100% and 92% of patients, respectively. Additionally, 84% of caregivers reported preferring VA-EEG if EEG data were needed in the future.

CONCLUSIONS

Video ambulatory EEG may be an effective diagnostic modality among children selected by clinicians and caregivers to undergo long-term EEG monitoring. Given it is effective as well as convenient, accessible, and lower cost than inpatient EEG monitoring, all of which align with our institution's quality goals, we intend to expand our VA-EEG Program.

Telehealth for patients with rare epilepsies

Recent developments in technology and exigencies of the COVID-19 pandemic have spurred innovations for telehealth in patients with rare epilepsies. This review details the many ways telehealth may be used in the diagnosis and management of rare, pharmacoresistant epilepsy and documents our experience as measured by surveying caregivers of pediatric patients with epilepsy. Most components of the epilepsy evaluation, including history and examination, neuroimaging, and electroencephalogram (EEG) can be performed or reviewed remotely, assuming similar technique and quality of diagnostic studies. Seizure and epilepsy diagnosis is enhanced through the assistance of caregiver smart phone video recordings and 'ambulatory' EEG. Monitoring patient seizure frequency through paper seizure diaries is now increasingly being replaced by electronic diaries in both clinical and research settings. Electronic seizure diaries have numerous advantages such as data durability, increased accessibility, real-time availability, and easier analysis. Telehealth enhances access to specialized epilepsy care, which has been shown to reduce mortality and improve patient compliance and outcomes. Telehealth can also enable evaluation of patients with rare epilepsy in centers of excellence and enhance enrollment in clinical trials. Reducing mortality risk in patients with epilepsy can be accomplished through remote counseling and addressing psychiatric co-morbidities. Findings from surveying caregivers of children with epilepsy treated at Children's National Hospital showed that 54/56 (96.4%) found that not having to commute to the appointment positively contributed to their telemedicine experience. Overall, most respondents had a positive experience with their telemedicine visit. Almost all respondents (98%) were either 'very happy' or 'happy' with their telemedicine visit and their ability to communicate over telemedicine with the provider and either 'very likely' or 'likely' to want to use telemedicine for some future clinic visits. Telehealth in rare epilepsies is feasible and, in many ways, comparable with traditional evaluation and management.

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.

How much time is enough? Establishing an optimal duration of recording for ambulatory video EEG

OBJECTIVE

Ambulatory video EEG allows for extended recording of EEG in the comfort of a patient's home. However, the optimal duration of recording to capture clinical events is yet to be established. The current study uses retrospective analyses to identify an optimal recording duration for at-home video EEG.

METHODS

A retrospective review was performed utilizing an anonymized database of ambulatory video EEG recordings performed between March and September 2020 with a national in-home EEG provider. Only completed assessments with neurologists' reads of raw data were reviewed, resulting in 3644 unique studies divided into three age cohorts: pediatrics (n = 941), adult (n = 2020), and geriatric (n = 683). Cohorts were characterized by assessment yield and time to first typical clinical event, as well as subsequent typical events over duration of recording.

RESULTS

Frequency distributions reveal over half of first events are captured within 12 hours, but longer recording durations capture a much wider majority of both first typical events, as well as the mean number of subsequent events (5 clinical events). In 72 hours, over 97% of first events were observed in adult and geriatric patients, as well as over 95% of the mean number of subsequent events. In children, time to first event was significantly earlier than either adult or geriatric samples, with 98% of first events, and 92.8% of the mean number of subsequent events being observed in 48 hours.

SIGNIFICANCE

These results from a large-scale, national dataset of patients using in-home EEG monitoring suggests recording at least 48 hours in duration for children, and at least 72 hours in duration for adult and geriatric samples, is optimal to maximize the likelihood of observing typical clinical events to facilitate diagnosis.

The Yield of Ambulatory EEG-Video Monitoring

INTRODUCTION

The availability of ambulatory EEG-video monitoring gives an alternative to traditional inpatient EEG-video, but its yield and diagnostic value are not well known. This study evaluates the yield of ambulatory EEG-video for the diagnosis of epilepsy.

METHODS

We retrospectively reviewed the ambulatory EEG-video monitoring data from 200 consecutive and unselected patients aged 12 years and older performed by a single company (RSC Diagnostic Services) between January 2018 and May 2018. Studies were processed by two senior certified long-term monitoring EEG technologists and interpreted by neurologists.

RESULTS

Of the 200 patients, 130 (65%) were women, mean age was 45 years. Mean duration of studies were 76.6 hours (range 23-175 hours). There were 110 studies (55%) with events recorded and 101 (92%) were captured on video. Epileptic events accounted for 17.8% (18/101) of the events captured and 9% (18/200) of our total cohort. Nonepileptic diagnosis accounted for 38% of the total number of patients in study (76/200).

CONCLUSION

Ambulatory EEG-video monitoring may be a useful alternative to inpatient epilepsy monitoring unit, particularly with high clinical suspicion for nonepileptic events.

Ambulatory EEG to Classify the Epilepsy Syndrome

SUMMARY

Recording of interictal epileptiform discharges to classify the epilepsy syndrome is one of the most common indications for ambulatory EEG. Ambulatory EEG has superior sampling compared with standard EEG recordings and advantages in terms of cost-effectiveness and convenience compared with a prolonged inpatient EEG study. Ambulatory EEG allows for EEG recording in all sleep stages and transitional states, which can be very helpful in capturing interictal epileptiform discharges. In the absence of interictal epileptiform discharges or in patients with atypical events, the characterization of an epilepsy syndrome may require recording of the habitual events. Diagnostic ambulatory EEG can be a useful alternative to inpatient video-EEG monitoring in a selected number of patients with frequent events who do not require medication taper or seizure testing for surgical localization.

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

BACKGROUND

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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