Challenges and directions in epilepsy diagnostics and therapeutics: Proceedings of the 17th Epilepsy Therapies and Diagnostics Development conference

Substantial efforts are underway toward optimizing the diagnosis, monitoring, and treatment of seizures and epilepsy. We describe preclinical programs in place for screening investigational therapeutic candidates in animal models, with particular attention to identifying and eliminating drugs that might paradoxically aggravate seizure burden. After preclinical development, we discuss challenges and solutions in the design and regulatory logistics of clinical trial execution, and efforts to develop disease biomarkers and interventions that may be not only seizure-suppressing, but also disease-modifying. As disease-modifying treatments are designed, there is clear recognition that, although seizures represent one critical therapeutic target, targeting nonseizure outcomes like cognitive development or functional outcomes requires changes to traditional designs. This reflects our increasing understanding that epilepsy is a disease with profound impact on quality of life for the patient and caregivers due to both seizures themselves and other nonseizure factors. This review examines selected key challenges and future directions in epilepsy diagnostics and therapeutics, from drug discovery to translational application.

Current state of the epilepsy drug and device pipeline

The field of epilepsy has undergone substantial advances as we develop novel drugs and devices. Yet considerable challenges remain in developing broadly effective, well-tolerated treatments, but also precision treatments for rare epilepsies and seizure-monitoring devices. We summarize major recent and ongoing innovations in diagnostic and therapeutic products presented at the seventeenth Epilepsy Therapies & Diagnostics Development (ETDD) conference, which occurred May 31 to June 2, 2023, in Aventura, Florida. Therapeutics under development are targeting genetics, ion channels and other neurotransmitters, and many other potentially first-in-class interventions such as stem cells, glycogen metabolism, cholesterol, the gut microbiome, and novel modalities for delivering electrical neuromodulation.

Reducing Time to Electroencephalography in Pediatric Convulsive Status Epilepticus: A Quality Improvement Initiative

BACKGROUND

Pediatric convulsive status epilepticus (CSE) is a neurological emergency utilizing electroencephalography (EEG) to guide therapeutic interventions. Guidelines recommend EEG initiation within one hour of seizure onset, but logistic and structural barriers often lead to significant delays. We aimed to reduce the time to EEG in pediatric CSE.

METHODS

From 2017 to 2022, we implemented process improvements, including EEG order sets with priority-based timing guidance, technologist workflow changes, a satisfaction survey, and feedback from key stakeholder groups, over five plan-do-study-act (PDSA) cycles. Seizure start time, time of EEG order, and time to EEG initiation were extracted. Time to interpretable EEG was determined from manual review of the EEG tracing.

RESULTS

Time from EEG order to interpretable EEG decreased by nearly 50%, from a median of 90 minutes to 48 minutes. There were clinically and statistically significant improvements in time from EEG order to EEG initiation, time from EEG order to interpretable EEG, and EEG start to interpretable EEG. Ongoing provider education and guidance enabled improvements, whereas a new electronic health care record negatively impacted electronic ordering. EEG technologists reported that they understood the importance of emergent EEG for clinical care and did not find that the new workflow caused excessive disruption.

CONCLUSIONS

Timely access to EEG for pediatric patients with CSE can be improved through clinical processes that use existing devices and that maintain the benefits of full-montage EEG recordings. Similar process improvement efforts may be generalizable to other institutions to increase adherence to guidelines and provide improved care.

Early-Life Epilepsies

Epilepsies are a diverse group of neurological disorders characterized by recurrent seizures. One-third of epilepsies are refractory to standard antiseizure medications. Epilepsy incidence is age-dependent with high incidence in neonates and infants. Epilepsy syndromes are classified based on clinical, electrographic, neuroimaging, age-dependent features of onset and the possibility of remission. Advances in genetic testing technology and improved access to clinical genetic testing, including whole exome sequencing, have facilitated a fundamental shift in gene discovery of monogenetic and polygenetic epilepsy, leading to precision medicine therapy and improved outcomes. Here, we review the self-limited epilepsy syndromes and developmental and epileptic encephalopathies that begin in the neonatal-infantile period with an emphasis on genetic etiology and the shifting landscape of treatment options based on genetic findings. [Pediatr Ann. 2023;52(10):e381-e387.].

Clinical outcomes of pediatric hemispherectomy following unsuccessful subhemispheric resection for refractory epilepsy: a case review study

OBJECTIVE

Epilepsy surgery remains one of the most underutilized procedures in epilepsy despite its proven superiority to other available therapies. This underutilization is greater in patients in whom initial surgery fails. This case series examined the clinical characteristics, reasons for initial surgery failure, and outcomes in a cohort of patients who underwent hemispherectomy following unsuccessful smaller resections for intractable epilepsy (subhemispheric group [SHG]) and compared them to those of a cohort of patients who underwent hemispherectomy as the first surgery (hemispheric group [HG]). The objective of this paper was to determine the clinical characteristics of patients in whom a small, subhemispheric resection failed, who went on to become seizure free after undergoing a hemispherectomy.

METHODS

Patients who underwent hemispherectomy at Seattle Children's Hospital between 1996 and 2020 were identified. Inclusion criteria for SHG were as follows: 1) patients ≤ 18 years of age at the time of hemispheric surgery; 2) initial subhemispheric epilepsy surgery that did not produce seizure freedom; 3) hemispherectomy or hemispherotomy after the subhemispheric surgery; and 4) follow-up for at least 12 months after hemispheric surgery. Data collected included the following: patient demographics; seizure etiology; comorbidities; prior neurosurgeries; neurophysiological studies; imaging studies; and surgical details-plus surgical, seizure, and functional outcomes. Seizure etiology was classified as follows: 1) developmental, 2) acquired, or 3) progressive. The authors compared SHG to HG in terms of demographics, seizure etiology, and seizure and neuropsychological outcomes.

RESULTS

There were 14 patients in the SHG and 51 patients in the HG. All patients in the SHG had Engel class IV scores after their initial resective surgery. Overall, 86% (n = 12) of the patients in the SHG had good posthemispherectomy seizure outcomes (Engel class I or II). All patients in the SHG who had progressive etiology (n = 3) had favorable seizure outcomes, with eventual hemispherectomy (1 each with Engel classes I, II, and III). Engel classifications posthemispherectomy between the groups were similar. There were no statistical differences in postsurgical Vineland Adaptive Behavior Scales Adaptive Behavior Composite scores or postsurgical full-scale IQ scores between groups when accounting for presurgical scores.

CONCLUSIONS

Hemispherectomy as a repeat surgery after unsuccessful subhemispheric epilepsy surgery has a favorable seizure outcome, with stable or improved intelligence and adaptive functioning. Findings in these patients are similar to those in patients who had hemispherectomy as their first surgery. This can be explained by the relatively small number of patients in the SHG and the higher likelihood of hemispheric surgeries to resect or disconnect the entire epileptogenic lesion compared to smaller resections.

Age-specific average head template for typically developing 6-month-old infants

Due to the rapid anatomical changes that occur within the brain structure in early human development and the significant differences between infant brains and the widely used standard adult templates, it becomes increasingly important to utilize appropriate age- and population-specific average templates when analyzing infant neuroimaging data. In this study we created a new and highly detailed age-specific unbiased average head template in a standard MNI152-like infant coordinate system for healthy, typically developing 6-month-old infants by performing linear normalization, diffeomorphic normalization and iterative averaging processing on 60 subjects' structural images. The resulting age-specific average templates in a standard MNI152-like infant coordinate system demonstrate sharper anatomical detail and clarity compared to existing infant average templates and successfully retains the average head size of the 6-month-old infant. An example usage of the average infant templates transforms magnetoencephalography (MEG) estimated activity locations from MEG's subject-specific head coordinate space to the standard MNI152-like infant coordinate space. We also created a new atlas that reflects the true 6-month-old infant brain anatomy. Average templates and atlas are publicly available on our website (http://ilabs.washington.edu/6-m-templates-atlas).

Time Course of Activity in Itch-Related Brain Regions: A Combined MEG–fMRI Study

Functional neuroimaging studies have identified itch-related brain regions. However, no study has investigated the temporal aspect of itch-related brain processing. Here this issue was investigated using electrically evoked itch in ten healthy adults. Itch stimuli were applied to the left wrist and brain activity was measured using magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). In the MEG experiment, the magnetic responses evoked by the itch stimuli were observed in the contralateral and ipsilateral frontotemporal regions. The dipoles associated with the magnetic responses were mainly located in the contralateral (nine subjects) and ipsilateral (eight subjects) secondary somatosensory cortex (SII)/insula, which were also activated by the itch stimuli in the fMRI experiment. We also observed an itch-related magnetic response in the posterior part of the centroparietal region in six subjects. MEG and fMRI data showed that the magnetic response in this region was mainly associated with itch-related activation of the precuneus. The latency was significantly longer in the ipsilateral than that in the contralateral SII/insula, suggesting the difference to be associated with transmission in the callosal fibers. The timing of activation of the precuneus was between those of the contralateral and ipsilateral SII/insula. Other sources were located in the premotor, primary motor, and anterior cingulate cortices (one subject each). This study is the first to demonstrate part of the time course of itch-related brain processing. Combining methods with high temporal and spatial resolution (e.g., MEG and fMRI) would be useful to investigate the temporal aspect of the brain mechanism of itch.