Depth versus surface: A critical review of subdural and depth electrodes in intracranial electroencephalographic studies.

Intracranial electroencephalographic (IEEG) recording, using subdural electrodes (SDEs) and stereoelectroencephalography (SEEG), plays a pivotal role in localizing the epileptogenic zone (EZ). SDEs, employed for superficial cortical seizure foci localization, provide information on two-dimensional seizure onset and propagation. In contrast, SEEG, with its three-dimensional sampling, allows exploration of deep brain structures, sulcal folds, and bihemispheric networks. SEEG offers the advantages of fewer complications, better tolerability, and coverage of sulci. Although both modalities allow electrical stimulation, SDE mapping can tessellate cortical gyri, providing the opportunity for a tailored resection. With SEEG, both superficial gyri and deep sulci can be stimulated, and there is a lower risk of afterdischarges and stimulation-induced seizures. Most systematic reviews and meta-analyses have addressed the comparative effectiveness of SDEs and SEEG in localizing the EZ and achieving seizure freedom, although discrepancies persist in the literature. The combination of SDEs and SEEG could potentially overcome the limitations inherent to each technique individually, better delineating seizure foci. This review describes the strengths and limitations of SDE and SEEG recordings, highlighting their unique indications in seizure localization, as evidenced by recent publications. Addressing controversies in the perceived usefulness of the two techniques offers insights that can aid in selecting the most suitable IEEG in clinical practice.

Hippocampal sclerosis and temporal lobe epilepsy following febrile status epilepticus: The FEBSTAT study.

OBJECTIVE: This study was undertaken to determine whether hippocampal T2 hyperintensity predicts sequelae of febrile status epilepticus, including hippocampal atrophy, sclerosis, and mesial temporal lobe epilepsy. METHODS: Acute magnetic resonance imaging (MRI) was obtained within a mean of 4.4 (SD = 5.5, median = 2.0) days after febrile status on >200 infants with follow-up MRI at approximately 1, 5, and 10 years. Hippocampal size, morphology, and T2 signal intensity were scored visually by neuroradiologists blinded to clinical details. Hippocampal volumetry provided quantitative measurement. Upon the occurrence of two or more unprovoked seizures, subjects were reassessed for epilepsy. Hippocampal volumes were normalized using total brain volumes. RESULTS: Fourteen of 22 subjects with acute hippocampal T2 hyperintensity returned for follow-up MRI, and 10 developed definite hippocampal sclerosis, which persisted through the 10-year follow-up. Hippocampi appearing normal initially remained normal on visual inspection. However, in subjects with normal-appearing hippocampi, volumetrics indicated that male, but not female, hippocampi were smaller than controls, but increasing hippocampal asymmetry was not seen following febrile status. Forty-four subjects developed epilepsy; six developed mesial temporal lobe epilepsy and, of the six, two had definite, two had equivocal, and two had no hippocampal sclerosis. Only one subject developed mesial temporal epilepsy without initial hyperintensity, and that subject had hippocampal malrotation. Ten-year cumulative incidence of all types of epilepsy, including mesial temporal epilepsy, was highest in subjects with initial T2 hyperintensity and lowest in those with normal signal and no other brain abnormalities. SIGNIFICANCE: Hippocampal T2 hyperintensity following febrile status epilepticus predicted hippocampal sclerosis and significant likelihood of mesial temporal lobe epilepsy. Normal hippocampal appearance in the acute postictal MRI was followed by maintained normal appearance, symmetric growth, and lower risk of epilepsy. Volumetric measurement detected mildly decreased hippocampal volume in males with febrile status.

Electroclinical features of myoclonic-tonic and spasm-tonic seizures in childhood.

Myoclonic-tonic (MT) and spasm-tonic (ST) seizures represent distinctive features in late infantile epileptic encephalopathy (LIEE). This commentary aims to delineate the electroclinical characteristics of MT and ST seizures, setting them apart from other seizure types. Our analysis encompasses 211 ST and MT seizures observed in 31 patients diagnosed with LIEE, providing a comprehensive overview of video-EEG features and polygraphic signatures. In MT seizures, EEG findings reveal a high-voltage diffuse spike/polyspike and wave discharge, often succeeded by diffuse electrodecrements. The amplitude-integrated EEG (aEEG) signature is described as a "reversed checkmark." Conversely, ST seizures exhibit EEG findings such as a vertex positive deflection after a slow-wave and relative electrodecrement, with intermixed epileptiform discharges. In comparison to MT seizures, polygraphic characteristics in ST seizures appear more distinct, featuring a brief rhomboid shape corresponding to the spasm, followed by a lengthier rectangular shape indicative of the tonic phase of the ST seizure. While the pathophysiology of ST and MT seizures remains inadequately understood, their concurrent occurrence and association with other seizure types (tonic, epileptic spasm, myoclonic) within the temporal context of LIEE and other epileptic encephalopathies prompt us to anticipate advancements in our understanding through future research. We hope that this study serves as a foundation for unraveling these complexities in the times to come.

Portable Headband Electroencephalogram in the Detection of Absence Epilepsy.

The accuracy of headband electroencephalogram (EEG) was compared to traditional EEG in pediatric patients with absence epilepsy. This study enrolled 10 patients with previously diagnosed absence epilepsy and examined the concordance of headband EEG and traditional EEG in the follow-up EEG of treated absence epilepsy. The study found a concordant result in 80% of cases providing a signal that absence epilepsy is an effective target for headband EEG. The study showcases a need for further research in headband EEG technology and continued improvements in technology.

Late infantile epileptic encephalopathy: A distinct developmental and epileptic encephalopathy syndrome.

OBJECTIVE: Within the spectrum of developmental and epileptic encephalopathy (DEE), there are a group of infants with features that are distinct from the well-recognized syndromes of early infantile developmental and epileptic encephalopathy (EIDEE), infantile epileptic spasm syndrome (IESS), and Lennox-Gastaut syndrome (LGS). We refer to this condition as late infantile epileptic encephalopathy (LIEE). Our objective was to highlight the characteristics of this group by analyzing patients who exhibit prototypical features. METHODS: From July 2022 to May 2023, we searched for LIEE features in pediatric patients who underwent epilepsy follow-up at the University of Chicago Comer Children's Hospital. RESULTS: Out of 850 patients evaluated, thirty patients (3.5%) were identified with LIEE based on electroclinical characteristics. These patients had an average onset of epilepsy at 6.8 months and an average onset of LIEE features at 18.1 months. The epilepsy etiology was most commonly genetic and metabolic (50%), followed by congenital cortical malformations (23%), acquired structural abnormalities (20%), and unknown (7%). The predominant seizure types were myoclonic-tonic (70%), spasm-tonic (50%), epileptic spasms (47%), tonic (43%), and myoclonic (43%) seizures. All patients reported a history of either spasm-tonic or myoclonic-tonic seizures in addition to other types. All patients had EEGs showing discontinuity, electrodecrements, or both along with diffuse slowing, background voltages between 100 and 300 µV, and superimposed multifocal, diffuse epileptiform discharges. Every patient, except one, fulfilled the definition of drug-resistant epilepsy, and all reported either moderate-to-severe or severe developmental delay. SIGNIFICANCE: Late infantile epileptic encephalopathy (LIEE) is characterized by several unique clinical and electrographic features. Typically, LIEE manifests in patients during the second year of life and occurs before two years of age, hence late infantile onset. The condition is commonly observed in infants with symptomatic epilepsy. Myoclonic-tonic and spasm-tonic seizures are the quintessential seizure types. The inter-ictal EEG exhibits more organization and lower voltages than seen with hypsarrhythmia and lacks the defining EEG characteristics of EIDEE, IESS, or LGS. We propose that LIEE is a distinct electroclinical syndrome within the spectrum of developmental and epileptic encephalopathies.

Pediatric epilepsy syndromes with associated developmental impairment.

In 2022, the International League Against Epilepsy revised their classification of epilepsy syndromes for clinicians to better understand the relationships between different epilepsy syndromes, their underlying causes, and their associated developmental and behavioral features. This review highlights portions of the current classification with an emphasis on epilepsy syndromes that readily present with developmental challenges and provides a unique framework, based on electroencephalography, to easily identify and understand these syndromes. Included in this review are a helpful categorization scheme with visual aid, descriptions of updated epilepsy syndromes, figures of relevant identifiers of syndrome and information regarding future directions toward treatment and research. Covered syndromes include developmental and epileptic encephalopathy, Dravet syndrome, Rasmussen syndrome, and infantile epileptic spasm syndrome, among others. WHAT THIS PAPER ADDS: The revised epilepsy syndrome classification by the International League Against Epilepsy aims to improve the outcomes for children with epilepsy. The electroencephalography features of epilepsy syndromes are grouped based on a categorization model. This model allows clinicians to understand overlapping phenotypes and aid with both identification and diagnosis.

Tandem pediatric neurosurgery: treatment of synostosis and intractable epilepsy. Illustrative case.

BACKGROUND: Hemispherectomy is a surgical procedure reserved for hemispheric intractable epilepsy. Sagittal craniosynostosis is a congenital disorder treated with open or endoscope-assisted approaches for synostosis correction. These procedures are not commonly performed in the same setting. OBSERVATIONS: In this report, the authors present a 6-month-old female with sagittal craniosynostosis, hemimegalencephaly, and intractable epilepsy who underwent a left hemispherotomy with open sagittal synostosis correction followed by cranial molding orthosis therapy. LESSONS: The report highlights the technical nuances of the procedure, but also discusses the possible genetic disorder responsible for both conditions, megalencephaly-capillary malformation syndrome.

Residency Training: A Practical Guide for Medical Students who are Planning a Future in Child Neurology.

At the time of graduation from medical school, medical students have been exposed primarily to adult neurology and have limited exposure to child neurology. Child neurology is a unique field that encompasses caring for children with neurological conditions ranging from routine to rare. There are many opportunities for a variety of unique careers in child neurology including both in the inpatient and outpatient setting. This article aims to provide practical advice for the medical student interested in child neurology to best prepare for a successful match and rewarding career.

Motor seizure semiology.

Motor semiology is a major component of epilepsy evaluation, which provides essential information on seizure classification and helps in seizure localization. The typical motor seizures include tonic, clonic, tonic-clonic, myoclonic, atonic, epileptic spasms, automatisms, and hyperkinetic seizures. Compared to the "positive" motor signs, negative motor phenomena, for example, atonic seizures and Todd's paralysis are also crucial in seizure analysis. Several motor signs, for example, version, unilateral dystonia, figure 4 sign, M2e sign, and asymmetric clonic ending, are commonly observed and have significant clinical value in seizure localization. The purpose of this chapter is to review the localization value and pathophysiology associated with the well-defined motor seizure semiology using updated knowledge from intracranial electroencephalographic recordings, particularly stereoelectroencephalography.

When in doubt, return to fundamentals (seizure semiology).

This case of drug resistant focal epilepsy highlights several invaluable teaching points. Hypotheses grounded in seizure semiology provide the best framework to ensure accurate interpretation of diagnostic testing. Without a hypothesis, information gathered from tests can be difficult to linearly piece together and can lead to poor patient outcomes. The case also provides a real-world conundrum of discordant test results that were ultimately rectified by re-visiting the initial hypothesis and cross-testing. Perinatal stroke continues to be a common etiology of drug resistant epilepsy. Patients can achieve seizure freedom and good quality of life with appropriate workup and in appropriate cases, surgery.

Modified Atkins diet in children with epilepsy with eyelid myoclonia (Jeavons syndrome).

BACKGROUND: Epilepsy with eyelid myoclonia(EEM) or Jeavons syndrome is considered a genetic generalized epilepsy with a typical age of onset in childhood. Many types of seizures can be observed, including eyelid myoclonia, absence, generalized tonic-clonic, and myoclonic seizures. Seizures tend to be difficult to control requiring polypharmacy treatment or become drug-resistant. Dietary therapy, particularly with Modified Atkins Diet (MAD), as a treatment of seizures in this syndrome has rarely been studied. We report efficacy and tolerability of MAD in children with epilepsy with eyelid myoclonia. METHODS: We reviewed medical records of children with EEM treated at the University of Chicago Ketogenic Diet program from 2017 to 2022. Patient's demography, seizure characteristics, EEG findings, response to treatment, and adverse effects were reviewed. RESULT: Six patients with EEM were identified. Average age of seizure onset was 6 (2-11) years and an average age when the MAD started was 10.7 (6-15) years. All patients were started on MAD and completed at least 6 months on the diet at the time of report. An average of 4 (0-9) anti-seizure medications (ASM) had been tried prior to the MAD. All patients achieved ketosis with an average level of serum beta-hydroxybutyrate of 1.9 (1.03-3.61) mmol/L. At the 6-month follow-up visit, all patients (100%) experienced a greater than 50% seizure reduction, 3/6 patients (50%) had more than 90% seizure reduction, 1/6 patients (17%) became seizure-free. All seizure types demonstrated a greater than 80% reduction in frequency.Absence and myoclonic seizures showed the greatest reduction with 100% seizure reduction. Eyelid myoclonia and generalized tonic-clonic seizures showed more than 80% seizure reduction.Moreover, all patients reported improvement in alertness, mood, and concentration. Initial weight loss and mild gastrointestinal disturbances were reported in 2/6 patients (33%) and corrected with dietary adjustment. CONCLUSION: The Modified Atkins Diet has shown to be effective and welltolerated for children with EEM in our study. Cognitive improvement has also been subjectively reported in all patients. Adverse effects are tolerable and correctable. The MAD, therefore, may be considered as a treatment option for patients with epilepsy with eyelid myoclonia.

Clinical presentation and evaluation of epilepsy with eyelid myoclonia: Results of an international expert consensus panel.

OBJECTIVE: The objective of this study was to determine areas of consensus among an international panel of experts for the clinical presentation and diagnosis of epilepsy with eyelid myoclonia (EEM; formerly known as Jeavons syndrome) to improve a timely diagnosis. METHODS: An international steering committee was convened of physicians and patients/caregivers with expertise in EEM. This committee summarized the current literature and identified an international panel of experts (comprising 25 physicians and five patients/caregivers). This international expert panel participated in a modified Delphi process, including three rounds of surveys to determine areas of consensus for the diagnosis of EEM. RESULTS: There was a strong consensus that EEM is a female predominant generalized epilepsy syndrome with onset between 3 and 12 years of age and that eyelid myoclonia must be present to make the diagnosis. There was a strong consensus that eyelid myoclonia may go unrecognized for years prior to an epilepsy diagnosis. There was consensus that generalized tonic-clonic and absence seizures are typically or occasionally seen in patients. There was a consensus that atonic or focal seizures should lead to the consideration of reclassification or alternate diagnoses. There was a strong consensus that electroencephalography is required, whereas magnetic resonance imaging is not required for diagnosis. There was a strong consensus to perform genetic testing (either epilepsy gene panel or whole exome sequencing) when one or a combination of factors was present: family history of epilepsy, intellectual disability, or drug-resistant epilepsy. SIGNIFICANCE: This international expert panel identified multiple areas of consensus regarding the presentation and evaluation of EEM. These areas of consensus may be used to inform clinical practice to shorten the time to the appropriate diagnosis.

Management of epilepsy with eyelid myoclonia: Results of an international expert consensus panel.

OBJECTIVE: There are limited data about the treatment and management of epilepsy with eyelid myoclonia (EEM). The objective of this study was to determine areas of consensus among an international panel of experts for the management of EEM (formerly known as Jeavons syndrome). METHODS: An international steering committee was convened of physicians and patients/caregivers with expertise in EEM. This committee summarized the current literature and identified an international panel of experts (comprising 25 physicians and five patients/caregivers). This panel participated in a modified Delphi process, including three rounds of surveys to determine areas of consensus for the treatment, other areas of management, and prognosis for EEM. RESULTS: There was a strong consensus for valproic acid as the first-line treatment, with levetiracetam or lamotrigine as preferable alternatives for women of childbearing age. There was a moderate consensus that ethosuximide and clobazam are also efficacious. There was a strong consensus to avoid sodium channel-blocking medications, except for lamotrigine, as they may worsen seizure control. There was consensus that seizures typically persist into adulthood, with remission occurring in <50% of patients. There was less agreement about other areas of management, including dietary therapy, lens therapy, candidacy for driving, and outcome. SIGNIFICANCE: This international expert panel identified multiple areas of consensus regarding the optimal management of EEM. These areas of consensus may inform clinical practice to improve the management of EEM. In addition, multiple areas with less agreement were identified, which highlight topics for further research.

The devil is in the details: Understanding how misinformation regarding epilepsy manifests in TikTok videos.

OBJECTIVE: This study sought to understand the amount of misinformation surrounding epilepsy on the social media platform, TikTok. METHODS: Videos from TikTok were searched using keyword "epilepsy." In all, 109 videos were categorized as personal experience videos, event videos, or educational videos. Misinformation surrounding each video was analyzed by two independent reviewers. The number of videos and views of each were tracked. RESULTS: Event videos garnered the most attention (80% of total views). Of the event videos, 26/47 contained misinformation in the form of calling a nonepileptic event an epileptic seizure (55%). Videos of nonepileptic events labeled as epileptic seizures amassed 109 956 400 views. SIGNIFICANCE: This novel study quantifies the amount of misinformation regarding epilepsy on the social media platform, TikTok. The results showcase that misinformation is very prevalent on the application. Most of the misinformation consists of the mislabeling of nonepileptic events as epileptic seizures. Physicians should be aware of cardinal features of nonepileptic events to better treat patients. The medical community must understand the type of misinformation people are exposed to in order to educate patients appropriately.

Core Features Differentiate Dravet Syndrome from Febrile Seizures.

An 11-month-old girl with febrile seizures and first unprovoked seizures was evaluated in the hospital. Relevant history included developmental delay and strong family history of febrile seizures and migraines. A routine electroencephalogram was performed and was abnormal due to the presence of a slowed posterior dominant rhythm, generalized spike-wave discharges, and multifocal sharp waves. The findings were concerning for a developmental and epileptic encephalopathy. Given the concern for a developmental and epileptic encephalopathy, a next generation sequence epilepsy gene panel was ordered which identified a pathogenic variant in SCN1A. The clinical history, electroencephalogram, and pathogenic variant were compatible with a diagnosis of Dravet syndrome. This Grand Rounds manuscript highlights the thought process, evaluation, differential diagnosis, treatment, and prognosis in Dravet syndrome.

A comprehensive narrative review of epilepsy with eyelid myoclonia.

Epilepsy with eyelid myoclonia (EEM) is a generalized epilepsy syndrome with childhood-onset and 2:1 female predominance that consists of: 1. eyelid myoclonia with or without absence seizures, 2. eye closure induced seizures or EEG paroxysms, 3. clinical or EEG photosensitivity. While eyelid myoclonia is the disease hallmark, other seizure types, including absence seizures and generalized tonic-clonic seizures, may be present. It is thought to have a genetic etiology, and around one-third of patients may have a positive family history of epilepsy. Recently, specific genetic mutations have been recognized in a minority patients, including in SYNGAP1, NEXMIF, RORB, and CHD2 genes. There are no randomized controlled trials in EEM, and the management literature is largely restricted to small retrospective studies. Broad-spectrum antiseizure medications such as valproate, levetiracetam, lamotrigine, and benzodiazepines are typically used. Seizures typically persist into adulthood, and drug-resistant epilepsy is reported in over 50%.

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.