Equipment Setup and Artifact Removal for Simultaneous Electroencephalogram and Functional Magnetic Resonance Imaging for Clinical Review in Epilepsy.

Simultaneous electroencephalogram and functional magnetic resonance imaging (EEG-fMRI) is a unique combined technique that provides synergy in the understanding and localization of seizure onset in epilepsy. However, reported experimental protocols for EEG-fMRI recordings fail to address details about conducting such procedures on epilepsy patients. In addition, these protocols are limited solely to research settings. To fill the gap between patient monitoring in an epilepsy monitoring unit (EMU) and conducting research with an epilepsy patient, we introduce a unique EEG-fMRI recording protocol of epilepsy during the interictal period. The use of an MR conditional electrode set, which can also be used in the EMU for a simultaneous scalp EEG and video recording, allows an easy transition of EEG recordings from the EMU to the scanning room for concurrent EEG-fMRI recordings. Details on the recording procedures using this specific MR conditional electrode set are provided. In addition, the study explains step-by-step EEG processing procedures to remove the imaging artifacts, which can then be used for clinical review. This experimental protocol promotes an amendment to the conventional EEG-fMRI recording for enhanced applicability in both clinical (i.e., EMU) and research settings. Furthermore, this protocol provides the potential to expand this modality to postictal EEG-fMRI recordings in the clinical setting.

Focal epilepsies: Update on diagnosis and classification.

Correctly diagnosing and classifying seizures and epilepsies is paramount to ensure the delivery of optimal care to patients with epilepsy. Focal seizures, defined as those that originate within networks limited to one hemisphere, are primarily subdivided into focal aware, focal impaired awareness, and focal to bilateral tonic-clonic seizures. Focal epilepsies account for most epilepsy cases both in children and adults. In children, focal epilepsies are typically subdivided in three groups: self-limited focal epilepsy syndromes (e.g., self-limited epilepsy with centrotemporal spikes), focal epilepsy of unknown cause but which do not meet criteria for a self-limited focal epilepsy syndrome, and focal epilepsy of known cause (e.g., structural lesions-developmental or acquired). In adults, focal epilepsies are often acquired and may be caused by a structural lesion such as stroke, infection and traumatic brain injury, or brain tumors, vascular malformations, metabolic disorders, autoimmune, and/or genetic causes. In addition to seizure semiology, neuroimaging, neurophysiology, and neuropathology constitute the cornerstones of a diagnostic evaluation. Patients with focal epilepsy who become drug-resistant should promptly undergo assessment in an epilepsy center. After excluding pseudo-resistance, these patients should be considered for presurgical evaluation as a means to identify the location and extent of the epileptogenic zone and assess their candidacy for a surgical procedure. The goal of this seminar in epileptology is to summarize clinically relevant information concerning focal epilepsies. This contributes to the ILAE's mission to ensure that worldwide healthcare professionals, patients, and caregivers continue to have access to high-quality educational resources concerning epilepsy.

Impact of the COVID-19 Pandemic on Epilepsy Center Practice in the United States.

BACKGROUND AND OBJECTIVES: Persons with epilepsy, especially those with drug resistant epilepsy (DRE), may benefit from inpatient services such as admission to the epilepsy monitoring unit (EMU) and epilepsy surgery. The COVID-19 pandemic caused reductions in these services within the US during 2020. This article highlights changes in resources, admissions, and procedures among epilepsy centers accredited by the National Association of Epilepsy Centers (NAEC). METHODS: We compared data reported in 2019, prior to the COVID-19 pandemic, and 2020 from all 260 level 3 and level 4 NAEC accredited epilepsy centers. Data were described using frequency for categorical variables and median for continuous variables and were analyzed by center level, center population category, and geographical location. Qualitative responses from center directors to questions regarding the impact from COVID-19 were summarized utilizing thematic analysis. Responses from the NAEC center annual reports as well as a supplemental COVID-19 survey were included. RESULTS: EMU admissions declined 23% (-21,515) in 2020, with largest median reductions in level 3 centers [-55 admissions (-44%)] and adult centers [-57 admissions (-39%)]. The drop in admissions was more substantial in the East North Central, East South Central, Mid Atlantic, and New England US Census divisions. Survey respondents attributed reduced admissions to re-assigning EMU beds, restrictions on elective admissions, reduced staffing, and patient reluctance for elective admission. Treatment surgeries declined by 371 cases (5.7%), with the largest reduction occurring in VNS implantations [-486 cases (-19%)] and temporal lobectomies [-227 cases (-16%)]. All other procedure volumes increased, including a 35% (54 cases) increase in corpus callosotomies. DISCUSSION: In the US, access to care for persons with epilepsy declined during the COVID-19 pandemic in 2020. Adult patients, those relying on level 3 centers for care, and many persons in the eastern half of the US were most affected.

Clinical Neurophysiology Fellowship Program Directors Survey on a Standardized Fellowship Match Process: A Call for Action.

PURPOSE: To survey US Clinical Neurophysiology (CNP) fellowship program directors on the nature of CNP and related training programs, current recruitment cycle, and views for a standardized process. METHODS: A 23-question electronic survey was sent to all 93 US Accreditation Council for Graduate Medical Education-accredited CNP fellowship program directors from December 2020 to January 2021. RESULTS: The response rate was 60%. There was great variability in the number of CNP positions and CNP tracks offered. The following tracks were identified: 48% EEG dominant, 26% EMG dominant, 22% split equally between EEG and EMG, and 2% and 1% were neurophysiologic intraoperative monitoring and autonomic dominant, respectively. Of the responding institutions, 43% offered a second year of training options to CNP fellows, mainly in conjunction with Epilepsy fellowship, which was pursued by 25% of CNP fellows. Many programs indicated flexibility in their design between different CNP tracks or between CNP and other related training programs based on the available candidates. The median percentage of CNP fellowship positions filled over the last 5 years was 80%, and there was great variation in the recruitment timeline across institutions. Overall, 86% of program directors favored a universal timeline and 71% favored a formal match for CNP. The respondents were split between an independent CNP match (39%) and joining the initiatives of affiliate societies on a standardized process (61%). CONCLUSIONS: There is significant heterogeneity in the makeup of the CNP fellowship programs and the recruitment process. The majority of CNP program directors are in favor of standardization of the recruitment process.

United States Epilepsy Center Characteristics: A Data Analysis From the National Association of Epilepsy Centers.

BACKGROUND AND OBJECTIVES: Patients with drug-resistant epilepsy (DRE) may benefit from specialized testing and treatments to better control seizures and improve quality of life. Most evaluations and procedures for DRE in the United States are performed at epilepsy centers accredited by the National Association of Epilepsy Centers (NAEC). On an annual basis, the NAEC collects data from accredited epilepsy centers on hospital-based epilepsy monitoring unit (EMU) size and admissions, diagnostic testing, surgeries, and other services. This article highlights trends in epilepsy center services from 2012 through 2019. METHODS: We analyzed data reported in 2012, 2016, and 2019 from all level 3 and level 4 NAEC accredited epilepsy centers. Data were described using frequency for categorical variables and median for continuous variables and were analyzed by center level and center population category. EMU beds, EMU admissions, epileptologists, and aggregate procedure volumes were also described using rates per population per year. RESULTS: During the period studied, the number of NAEC accredited centers increased from 161 to 256, with the largest increases in adult- and pediatric-only centers. Growth in EMU admissions (41%), EMU beds (26%), and epileptologists (109%) per population occurred. Access to specialized testing and services broadly expanded. The largest growth in procedure volumes occurred in laser interstitial thermal therapy (LiTT) (61%), responsive neurostimulation (RNS) implantations (114%), and intracranial monitoring without resection (152%) over the study period. Corpus callosotomies and vagus nerve stimulator (VNS) implantations decreased (-12.8% and -2.4%, respectively), while growth in temporal lobectomies (5.9%), extratemporal resections (11.9%), and hemispherectomies/otomies (13.1%) lagged center growth (59%), leading to a decrease in median volumes of these procedures per center. DISCUSSION: During the study period, the availability of specialty epilepsy care in the United States improved as the NAEC implemented its accreditation program. Surgical case complexity increased while aggregate surgical volume remained stable or declined across most procedure types, with a corresponding decline in cases per center. This article describes recent data trends and current state of resources and practice across NAEC member centers and identifies several future directions for driving systematic improvements in epilepsy care.

Incident epilepsy in the cognitively normal geriatric population, irrespective of seizure control, impairs quality of life.

PURPOSE OF THE RESEARCH: The geriatric population is the fastest-growing population in the United States and the impact of incident epilepsy on the cognitively intact geriatric population is not well-studied. Understanding how epilepsy affects the elderly is important to improve the quality of treatment and care for our aging population. This study sought to address the impact of incident epilepsy on the perceived Quality of Life (QOL) in cognitively intact elderly using the SF-36 questionnaire. METHODS: Nine hundred and twenty-seven participants were assessed from a community-based cohort. Based on a history of subsequent development of new-onset seizures, participants were divided into two groups, an incident seizure group that developed new-onset seizures after 65 years of age and the control group without incident seizures. Of this, six hundred eleven were analyzed with the SF-36 questionnaire after excluding for cognitive decline and inconsistent medical data. PRINCIPAL RESULTS: Statistically significant differences were found in 9 items on SF-36, involving perception of increased physical disability (p < 0.01; t-test), frailty (p < 0.04; t-test), emotional health limitations (p < 0.03; t-test), anxiety and sadness (p < 0.04; t-test), problems interfering with social activities (p < 0.0001; t-test). No between-group differences were found for demographic variables including age, education, gender, or minority status. Among the 611 subjects who remained cognitively normal across all longitudinal visits, 12 reported a history of new-onset seizures. Ten of these 12 subjects were seizure free as a result of treatment, with only 2 experiencing recent seizures. The incidence of seizures in our population was 300 per 100,000 person years. MAJOR CONCLUSIONS: This study identified the elderly population with incident epilepsy as a subgroup with an unmet health need, and healthcare professionals should address the potential impact of seizures with their geriatric patients to ensure comprehensive care.

Approach to Loss of Consciousness: Distinguishing Epileptic Seizures, Psychogenic Nonepileptic Seizures, and Syncope.

Transient loss of consciousness (TLOC) is a common emergent neurological issue, which can be attributed to syncope, epileptic seizures, and psychogenic nonepileptic seizures. The purpose of this article is to outline an approach to diagnosing the most common etiologies of TLOC by focusing on the importance of the history and physical examination, as well as targeted diagnostic tests.

Artifacts That Can Be Misinterpreted as Interictal Discharges.

It is presumed that the EEG records only cerebral activity. However, frequently it can include other electrical activities, referred to as noise or artifact, which are not of cerebral origin. In the last few decades, evolution in digital technology has greatly improved the ability to record and display interpretable EEG. With the widespread availability of prolonged EEG recording, new artifacts have been described. The addition of concomitant video with audio during recordings has allowed in most instances to determine the source of certain artifacts. One of the challenges of interpreting EEGs consists of identifying artifacts correctly. Some of the EEG artifacts are so distinctive in appearance that the experienced reader can readily identify them. It is not uncommon for normal EEGs to be overinterpreted, especially by inexperienced readers. Failing to identify artifacts correctly can lead to "over reading" a study and doing so can result in misdiagnosis of epilepsy. This in turn can result in inappropriate treatments that ultimately can have serious clinical implications. This review will provide a description of the most commonly encountered artifacts that mimic spike or sharp waves, also referred to as interictal epileptiform discharges. In addition, we will describe troubleshooting approaches to eliminate these artifacts whenever possible. Artifacts that mimic ictal discharges will be reviewed in a different section.

Evaluating an Interdisciplinary EEG Initiative on In-Training Examination EEG-Related Item Scores for Anesthesiology Residents.

PURPOSE: Clinical neurophysiology is an evolving area of medicine with clinical applications in intensive care unit and intraoperative settings, where EEG is used. An interdisciplinary module was implemented over 7 years in one institution to strengthen anesthesiology residents' EEG education. This study researched the module's outcome by evaluating participants' specific performance on EEG-related questions (keywords) through independent testing, i.e., the in-training examinations (ITEs). METHODS: Residency program ITE performance reports from 2002 to 2014 were searched for EEG keyword items. The ITE uses images for assessment. Analysis of variance was used to evaluate differences in the composite performance (mean percent correct on EEG-related keywords) of anesthesiology trainees from their clinical anesthesia year 1 (CA-1) to their clinical anesthesia year 3 (CA-3) who received the education module and compared with those who did not receive the training module, as well as compared with the national average for the corresponding training level. RESULTS: Residents who received the education module (mean percent correct = 83.3%, 95% CI: 74.0-92.7) performed significantly better than residents within the same program who did not receive the module (P = 0.04; mean difference = 22.0%, 95% CI: 1.0-43.0), as well as national residents on the same keywords (P = 0.01; mean difference = 23.4%, 95% CI: 3.9-42.9). Differences between residents who did not receive the module and national residents (matched for same keywords) were not statistically significant (P = 0.983, mean difference = 5.2%, 95% CI: -17.3 to 27.7). CONCLUSIONS: The multidisciplinary education module was effective for the EEG-specific topics as measured by the national ITE examination performance that resulted in sustained learning over time.

Status epilepticus alert reduces time to administration of second-line antiseizure medications.

BACKGROUND: Status epilepticus (SE) is a neurologic emergency with high morbidity and mortality. Delays in SE treatment are common in clinical practice and can be associated with poorer outcomes. Our goal was to determine whether the implementation of an SE alert protocol improves time to administration of a second-line antiseizure medication (ASM) in hospitalized adults. METHODS: We developed and implemented an inpatient SE alert system. A quasiexperimental cohort study was performed. We analyzed all patients aged 18-85 years who were managed at the University of Kentucky Medical Center using the SE alert protocol between March 2015 and June 2017 (n = 19). Controls were the first 20 consecutive patients treated for SE over the same time period, but who were managed with usual care (i.e., without SE alert protocol). RESULTS: Time to administration of a second-line ASM was shorter with the use of the SE alert system (22.21 ± 3.44 minutes) compared to usual care (58.30 ± 6.72 minutes; p < 0.0001). CONCLUSION: Implementation of an SE alert system led to a marked improvement in time to administration of a second-line ASM. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for adult inpatients treated for SE, implementation of an SE alert protocol reduces time to administration of second-line ASM.

Noninvasive seizure prediction using autonomic measurements in patients with refractory epilepsy.

There is resurgent interest in the role played by autonomic dysfunction in seizure generation. Advances in wearable sensors make it convenient to track many autonomic variables in patient populations. This study assesses peri-ictal changes in surrogate measures of autonomic activity for their predictive value in epilepsy patients. We simultaneously recorded fronto-central surface EEG and submental EMG to score vigilance state, intracranial EEG (iEEG) to compute several electrophysiological variables (EV), and measurements (heart rate, blood volume pulse, skin impedance, and skin temperature) relevant to autonomic function (AV) using a wrist-worn sensor from three patients. A naïve Bayes classifier was trained on these features and tested using five-fold cross- validation to determine whether preictal and interictal sleep (or wake) epochs could be distinguished from each other using either AV or EV features. Of 16 EV features, beta power, gamma power (30-45 Hz and 47-75 Hz), line length, and Teager energy showed significant differences for preictal versus interictal sleep (or wake) state in each patient (t test: $p<0.001$). At least one AV was significantly different in each patient for interictal and preictal sleep (or wake) segments ($p<0.001$). Using AV features, the classifier labeled preictal sleep epochs with 84% sensitivity, 79% specificity, and 64% kappa; and 78%, 80% and 55% respectively for preictal wake epochs. Using EV, the classifier labeled preictal sleep epochs with 69% sensitivity, 64% specificity, and 33% kappa; and 15%, 93% and 10% respectively for preictal wake epochs.

Pharmacokinetics and Clinical Utility of Valproic Acid Administered via Continuous Infusion.

INTRODUCTION: Valproic acid is a versatile antiepileptic drug that is often used in the acute care setting. Intravenous valproic acid lends itself well to a continuous infusion as it exhibits a relatively short half-life. We evaluated the pharmacokinetics and clinical efficacy of continuous infusion valproic acid in hospitalized patients with migraine and seizures. METHODS: A retrospective cohort study was performed utilizing information from the medical records of patients receiving an intravenous continuous infusion of valproic acid. Patients were included if they were aged 1 month to 85 years and they received a continuous infusion of valproic acid. Therapeutic response, common adverse effects, and the pharmacokinetic profile of valproic acid were evaluated. RESULTS: Continuous infusion valproic acid led to a concentration within the desired range (50-100 µg/ml) in 83.4% of patients, a rate that was higher in pediatric patients. The clinical response rate was also higher in pediatric patients with seizures or migraines and appeared to be better when the concentration was >75 µg/ml. Analysis of safety parameters suggests similar safety considerations to valproic acid when administered via intermittent infusion. CONCLUSIONS: Continuous infusion valproic acid appears to be a safe, effective, and predictable manner by which to administer valproic acid to pediatric and adult patients admitted to the hospital.

Prior Podcast Experience Moderates Improvement in Electroencephalography Evaluation After Educational Podcast Module.

BACKGROUND: There is continued interest in using technology to enhance medical education and the variables that may affect its success. METHODS: Anesthesiology residents and fourth-year medical students participated in an electroencephalography (EEG) educational video podcast module. A 25-item evaluation tool was administered before any EEG education was provided (baseline), and the podcast was then viewed. Another 25-item evaluation tool was administered after podcast viewing (after podcast). Ten EEG interpretations were completed with a neurophysiologist with an additional 25-item evaluation tool administered after the interpretations (after 10 EEG interpretations). Participants were surveyed concerning technology and podcasting experience before the educational module and their responses to the podcast educational model. Multiple analyses were performed (1) to evaluate differences in improvement in EEG evaluation scores between the podcast module and the standard didactics (control group); and (2) to evaluate potential moderation by technology and the podcast experience on the change in mean EEG evaluation scores from after the podcast module to after 10 EEG interpretations. RESULTS: A total of 21 anesthesiology residents and 12 fourth-year medical students participated. Scores on the 25-item evaluation tool increased with each evaluation time (P ≤ 0.001). Moderation analyses revealed that individuals with more podcast experience (≥4 previous podcasts) had greater increases in scores after a podcast and 10 EEG interpretations compared with individuals with less experience (≤3 previous podcasts) (P = 0.027). Furthermore, compared with a control group with similar baseline characteristics that received only standard didactics without a podcast, those in the podcast group had greater increases in mean EEG evaluation scores between baseline and after 10 EEG interpretations. CONCLUSIONS: In reviewing the improvement in EEG evaluation after a podcast education module, those with more podcast experience achieved greater gains in EEG evaluation scores. For EEG education, those receiving the podcast education module showed greater increases in scores compared with those receiving didactic teaching without podcasting, as measured by change in a mean EEG evaluation scores.

Tonic glutamate in CA1 of aging rats correlates with phasic glutamate dysregulation during seizure.

OBJECTIVE: Characterize glutamate neurotransmission in the hippocampus of awake-behaving rodents during focal seizures in a model of aging. METHODS: We used enzyme-based ceramic microelectrode array technology to measure in vivo extracellular tonic glutamate levels and real-time phasic glutamate release and clearance events in the hippocampus of awake Fischer 344 rats. Local application of 4-aminopyridine (4-AP) into the CA1 region was used to induce focal motor seizures in different animal age groups representing young, late-middle aged and elderly humans. RESULTS: Rats with the highest preseizure tonic glutamate levels (all in late-middle aged or elderly groups) experienced the most persistent 4-AP-induced focal seizure motor activity (wet dog shakes) and greatest degree of acute seizure-associated disruption of glutamate neurotransmission measured as rapid transient changes in extracellular glutamate levels. SIGNIFICANCE: Increased seizure susceptibility was demonstrated in the rats with the highest baseline hippocampal extracellular glutamate levels, all of which were late-middle aged or aged animals. The manifestation of seizures behaviorally was associated with dynamic changes in glutamate neurotransmission. To our knowledge, this is the first report of a relationship between seizure susceptibility and alterations in both baseline tonic and phasic glutamate neurotransmission.

The impact of an interdisciplinary electroencephalogram educational initiative for critical care trainees.

PURPOSE: The purpose of this study is to evaluate the effectiveness of an interdisciplinary electroencephalogram (EEG) educational module for critical care training. Electroencephalogram is increasingly used for diagnosis, monitoring, and treatment decisions in critically ill patients with neurologic and nonneurologic disorders. Continuous EEG monitoring has an expanded role in the intensive care unit as an additional evaluation tool for critically ill patients with altered mental status. MATERIALS AND METHODS: During a neurosurgical intensive care rotation, pulmonary critical care fellows participated in an EEG curriculum covering didactics, clinical exposure, and EEG interpretations. Using 25-question evaluation tools, including EEG interpretations, participants were assessed before EEG instruction and after curriculum completion. RESULTS: Nine fellows completed the pilot study. Evaluation scores increased from 7.56±2.24 to 16.67±2.96 (P<.001). CONCLUSIONS: An interdisciplinary approach was effective for increasing EEG knowledge in critical care fellows as measured by the assessment tools. As an added potential benefit, the pulmonary fellows also learned about sleep disorder-related EEG. This model can be replicated in other institutions for trainees of other specialties interested in critical care.

Education research: evaluating the use of podcasting for residents during EEG instruction: a pilot study.

OBJECTIVE: Educational methods for residents are shifting toward greater learner independence aided by technological advances. A Web-based program using a podcast was created for resident EEG instruction, replacing conventional didactics. The EEG curriculum also consisted of EEG interpretations under the tutelage of a neurophysiologist. This pilot study aimed to objectively evaluate the effectiveness of the podcast as a new teaching tool. METHODS: A podcast for resident EEG instruction was implemented on the Web, replacing the traditional lecture. After Institutional Review Board approval, consent was obtained from the participating residents. Using 25-question evaluation tools, participants were assessed at baseline before any EEG instruction, and reassessed after podcasting and after 10 clinical EEG exposures. Each 25-item evaluation tool contained tracings used for clinical EEG interpretations. Scores after podcast training were also compared to scores after traditional didactic training from a previous study among anesthesiology trainees. RESULTS: Ten anesthesiology residents completed the study. The mean scores with standard deviations are 9.50 ± 2.92 at baseline, 13.40 ± 3.31 (p = 0.034) after the podcast, and 16.20 ± 1.87 (p = 0.019) after interpreting 10 EEGs. No differences were noted between the mean educational tool scores for those who underwent podcasting training compared to those who had undergone traditional didactic training. CONCLUSION: In this pilot study, podcast training was as effective as the prior conventional lecture in meeting the curricular goals of increasing EEG knowledge after 10 EEG interpretations as measured by assessment tools.

The effectiveness of an interdisciplinary approach to EEG instruction for residents(r).

Expanding EEG use calls for education during postgraduate training. We performed a study to see whether an innovative, interdisciplinary approach to EEG instruction for residents achieved curriculum goals of increasing knowledge of EEG use and interpretation. A 45-minute EEG educational module was developed by a clinical neurophysiologist and a neurocritical care anesthesiologist. After institutional review board approval and consent, neurologic surgery residents were evaluated using a 25-question assessment tool before and after the module to assess its impact. This tool included EEG tracing interpretations. Nine of 10 residents completed the study. Assessment tool scores increased from a mean of 12.00 +/- 1.87 before the educational module to 19.67 +/- 2.06 (P < 0.001) after the educational module. This innovative, collaborative approach for EEG instruction of residents using the expertise of a clinical neurophysiologist met the curriculum goals after a 45-minute educational module as measured by the study assessment tool.

Sporadic Creutzfeldt-Jakob disease presenting as nonconvulsive status epilepticus case report and review of the literature.

Creutzfeldt-Jakob disease (CJD) is the most common transmissible human spongiform encephalopathy. Seizures and status epilepticus (SE) are an uncommon finding in CJD. We report a 64-year-old woman with rapid cognitive decline who had electroencephalographic (EEG) changes suggestive of nonconvulsive status epilepticus (NCSE). She was later diagnosed with sporadic CJD (sCJD). We also reviewed the literature for published cases on this topic. MEDLINE was employed to identify all published reports of CJD and SE. We identified 8 references with a total of 12 cases with CJD and NCSE. sCJD should be considered in the differential diagnosis of any patient who presents with rapid cognitive decline and EEG changes consistent with status epilepticus.