Super-selective Wada test for pre-surgical leg motor function assessment: A case report

INTRODUCTION

Wada test is well-known to assess lateralization of memory and language functions; however, super-selective Wada (ss-Wada) to evaluate motor leg function is rare. We present a ss-Wada test within the anterior cerebral artery (ACA) to assess the motor function of the leg.

METHODS

Retrospective chart review.

RESULTS

Comprehensive phase-I/II surgical evaluation revealed an ictal focus around the left post-central gyrus with immediate involvement around the left para-central regions. To avoid potential right leg motor dysfunction with the surgery, the patient underwent a ss-Wada procedure. Angiography revealed bilateral ACAs were supplied by the left A1 segment. Super-selective microcatheter injection of amobarbital into the left ACA was performed to avoid cross-filling the contralateral ACA. The ss-Wada test confirmed no right leg motor impairment. Afterward, a craniotomy with direct cortical stimulation confirmed that the left-sided ictal/peri-ictal zone had no clear leg motor function. The patient underwent disconnection of that region and remained seizure-free at 10-month post-op follow-up without any motor or sensory deficits in the right limbs.

CONCLUSION

This case demonstrates the proof of concept for ss-Wada in assessing lower extremity motor function. The ss-Wada procedure accurately predicted no motor deficits in the right leg, consistent with preserved motor function post-surgery.

Responsive neurostimulation of thalamic nuclei for regional and multifocal drug-resistant epilepsy in children and young adults

OBJECTIVE

Responsive neurostimulation (RNS) is a US FDA-approved form of neuromodulation to treat patients with focal-onset drug-resistant epilepsy (DRE) who are ineligible for or whose condition is refractory to resection. However, the FDA approval only extends to use in patients with one or two epileptogenic foci. Recent literature has shown possible efficacy of thalamic RNS in patients with Lennox-Gastaut syndrome and multifocal epilepsy. The authors hypothesized that RNS of thalamic nuclei may be effective in seizure reduction for patients with multifocal or regionalized-onset DRE.

METHODS

The authors performed a retrospective chart review of all patients who had an RNS device managed at Texas Children's Hospital between July 2016 and September 2023, with at least one active electrode in the thalamic nuclei and ≥ 12 months of postimplantation follow-up. Information conveyed by the patient or their caregiver provided data on the change in the clinical seizure frequency, quality of life (QOL), and seizure severity between the preimplantation baseline visit and the last office visit (LOV).

RESULTS

Thirteen patients (ages 8-24 years) were identified with active RNS leads in thalamic nuclei (11 centromedian and 2 anterior nucleus). At LOV, 46% of patients reported 50%-100% clinical seizure reduction (classified as responders), 15% reported 25%-49% reduction, and 38% reported < 25% reduction or no change. Additionally, 42% of patients reported subjective improvement in QOL and 58% reported improved seizure severity. Patients with focal cortical dysplasia (FCD) responded strongly: 3 of 5 (60%) reported ≥ 80% reduction in seizure burden and improvement in seizure severity and QOL. Patients with multifocal epilepsy and bilateral thalamocortical leads also did well, with all 3 reporting ≥ 50% reduction in seizures.

CONCLUSIONS

RNS of thalamic nuclei shows promising results in reducing seizure burden for patients with multifocal or regional-onset DRE, particularly in a bilateral thalamocortical configuration or when addressing an underlying FCD.

Vagus nerve stimulation and heart rate variability: A scoping review of a somatic oscillatory signal

The goal of this review is to synthesize the literature on vagus nerve stimulator (VNS)-related changes in heart rate variability (HRV) in patients with drug-resistant epilepsy (DRE) and assess the role of these changes in seizure relief. A scoping literature review was performed with the following inclusion criteria: primary articles written in English, involved implantable VNS in humans, and had HRV as a primary outcome. Twenty-nine studies were retrieved, however with considerable heterogeneity in study methods. The overall depression in HRV seen in DRE patients compared to healthy controls persisted even after VNS implant, indicating that achieving "healthy" HRV is not necessary for VNS therapeutic success. Within DRE patients, changes in frequency domain parameters six months after VNS implant returned to baseline after a year. The mechanism of how VNS reduces seizure burden does not appear to be significantly related to alterations in baseline HRV. However, the subtlety of sympathetic/parasympathetic signaling likely requires a more structured approach to experimental and analytic techniques than currently found in the literature.

Efficacy of vagus nerve stimulation in managing drug-resistant absence epilepsy syndromes

PURPOSE

Around 11% of patients with absence epilepsy develop drug-resistant absence epilepsy (DRAE), and are at increased risk for developing psychiatric and neurologic comorbidities. Current therapeutic options for DRAE are limited. The purpose of this study was to assess the efficacy of vagus nerve stimulation (VNS) in treating DRAE.

METHODS

Our institution maintains a database of patients who received VNS between 2010 and 2022. We identified DRAE patients who were <18 years of age at seizure onset, were electro-clinically diagnosed with an absence epilepsy syndrome (childhood absence, juvenile absence, or Jeavons Syndrome) by an epileptologist, and had normal brain imaging. The primary outcome measure was post-VNS absence seizure frequency.

RESULTS

Twenty-six patients (M/F:14/12) were identified. Median age at seizure onset was 7 years (IQR 4-10) and patients experienced seizures for 6 years (IQR 4.3-7.6) before VNS. After VNS, the median absence seizure frequency reduced to 1.5 days (IQR 0.1-3.5) per week from 7 days (IQR 7-7), a 66% reduction seizure frequency. VNS responder rate was 80%, and seven patients achieved seizure freedom. There was no significant effect on VNS efficacy between the time from DRAE diagnosis to VNS placement (p = 0.067) nor the time from first seizure onset to VNS implant (p = 0.80). The median follow-up duration was 4.1 years (IQR 2.4-6.7), without any significant association between follow-up duration and VNS efficacy (r2=0.023) CONCLUSIONS: VNS is effective in managing DRAE. The responder rate was 80%; seizure improvement was independent of age at both seizure onset and latency to VNS after meeting DRAE criteria.

Pediatric neuromodulation for drug-resistant epilepsy: Survey of current practices, techniques, and outcomes across US epilepsy centers

Neuromodulation via Responsive Neurostimulation (RNS) or Deep Brain Stimulation (DBS) is an emerging treatment strategy for pediatric drug-resistant epilepsy (DRE). Knowledge gaps exist in patient selection, surgical technique, and perioperative care. Here, we use an expert survey to clarify practices. Thirty-two members of the Pediatric Epilepsy Research Consortium were surveyed using REDCap. Respondents were from 17 pediatric epilepsy centers (missing data in one): Four centers implant RNS only while 13 implant both RNS and DBS. Thirteen RNS programs commenced in or before 2020, and 10 of 12 DBS programs began thereafter. The busiest six centers implant 6-10 new RNS devices per year; all DBS programs implant <5 annually. The youngest RNS patient was 3 years old. Most centers (11/12) utilize MP2RAGE and/or FGATIR sequences for planning. Centromedian thalamic nuclei were the unanimous target for Lennox-Gastaut syndrome. Surgeon exposure to neuromodulation occurred mostly in clinical practice (14/17). Clinically significant hemorrhage (n = 2) or infection (n = 3) were rare. Meaningful seizure reduction (>50%) was reported by 81% (13/16) of centers. RNS and DBS are rapidly evolving treatment modalities for safe and effective treatment of pediatric DRE. There is increasing interest in multicenter collaboration to gain knowledge and facilitate dialogue. PLAIN LANGUAGE SUMMARY: We surveyed 32 pediatric epilepsy centers in USA to highlight current practices of intracranial neuromodulation. Of the 17 that replied, we found that most centers are implanting thalamic targets in pediatric drug-resistant epilepsy using the RNS device. DBS device is starting to be used in pediatric epilepsy, especially after 2020. Different strategies for target identification are enumerated. This study serves as a starting point for future collaborative research.

A Comprehensive Examination of Clinical Characteristics and Determinants of Long-Term Outcomes in Pediatric Cerebral Sinus Venous Thrombosis

BACKGROUND

To analyze the clinical and neuroimaging features, risk factors, treatment choices, and long-term clinical outcomes in children with cerebral sinus venous thrombosis (CSVT).

METHODS

This is a retrospective cohort study of children diagnosed with CSVT between 2002 and 2018 at Texas Children's Hospital.

RESULTS

A total of 183 children (male: 62.3%) with CSVT were included. The average presenting age was 7.7 years (S.D.: 5.6). The mean follow-up duration was 33.7 months (S.D.: 38.6). The most common presenting clinical feature was headache (36.6%). Head and neck infections other than meningitis (36.6%) were the most common risk factors. Prevalent neurological examination findings included motor deficit (21.3%) and altered mental status (AMS, 20.2%). Neuroimaging features included hemorrhagic infarction (19.6%), ischemic infarction (8.2%), and intracranial hemorrhage without infarction (5.5%). The most common site of thrombosis was the superior sagittal sinus (37.2%), with 78.2% of patients demonstrating involvement of multiple sinuses. Treatment of choice was low-molecular-weight heparin in 69.4% of patients. Factors associated with worse clinical outcomes included head and neck infections, malignancy (other than hematologic), cardiac disease, and recent surgery; seizure and dehydration on initial presentation; motor abnormalities and AMS on initial examination; ischemic infarct only; and involvement of vein of Trolard on neuroimaging. Thrombus condition on repeat imaging, receiving any anticoagulant/antithrombotic treatment, treatment duration, or follow-up duration was not associated with severity of long-term outcome.

CONCLUSIONS

CSVT may lead to unfavorable long-term outcomes in a remarkable portion of pediatric patients. Thus, a high index of suspicion and early and appropriate management of pediatric CSVT is imperative.

A multi-center comparison of surgical techniques for corpus Callosotomy in pediatric drug-resistant epilepsy

OBJECTIVES

Corpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug-resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi-institutional epilepsy surgery database to characterize the use of CC across participating centers.

METHODS

Data were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0-18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically.

RESULTS

Eighty-three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0-9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1-20) and 10.46 (.2-20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini-craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow-up was 12.8 months (range 1-39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant.

SIGNIFICANCE

CC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less-invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.

Epilepsy surgery in children with genetic etiologies: A prospective evaluation of current practices and outcomes

OBJECTIVE

This study assesses current practices and outcomes of epilepsy surgery in children with a genetic etiology. It explores the pre-surgical workup, types of surgeries, and post-surgical outcomes in a broad array of disorders.

METHODS

Patients ≤18 years who completed epilepsy surgery and had a known genetic etiology prior to surgical intervention were extrapolated from the Pediatric Epilepsy Research Consortium (PERC) surgery database, across 18 US centers. Data were assessed univariably by neuroimaging and EEG results, genetic group (structural gene, other gene, chromosomal), and curative intent. Outcomes were based on a modified International League Against Epilepsy (ILAE) outcome score.

RESULTS

Of 81 children with genetic epilepsy, 72 % had daily seizures when referred for surgery evaluation, which occurred a median of 2.2 years (IQR 0.3, 5.2) after developing drug resistance. Following surgery, 68 % of subjects had >50 % seizure reduction, with 33 % achieving seizure freedom [median follow-up 11 months (IQR 6, 17). Seizure freedom was most common in the monogenic structural group, but significant palliation was present across all groups. Presence of a single EEG focus was associated with a greater likelihood of seizure freedom (p=0.02).

SIGNIFICANCE

There are meaningful seizure reductions following epilepsy surgery in the majority of children with a genetic etiology, even in the absence of a single structural lesion and across a broad spectrum of genetic causes. These findings highlight the need for expedited referral for epilepsy surgery and support of a broadened view of which children may benefit from epilepsy surgery, even when the intent is palliative.

Externalization of an infected vagus nerve stimulator generator without a break in anti-seizure therapy: a technical note

INTRODUCTION

Vagus nerve stimulation (VNS) is a widely used treatment for drug-resistant epilepsy. An infection of the VNS generator pocket occurs in 3-8% of cases. Current standard of care requires the removal of the device, antibiotic therapy, and then replacement of the device. The consequential break in VNS therapy leaves patients highly susceptible to seizures.

METHODS

Retrospective case report.

RESULTS

The externalized generator continued to provide electroceutical coverage of the patient's seizures while the pocket was sterilized with IV antibiotics as well as betadine and local antibiotics. The externalized generator was kept safe against the patient's chest with ioban and an entriely new system was implanted on post-externalization day 5. The patient is now 7 months post-operative and without any evidence of infection.

CONCLUSIONS

We report successful management of an infected VNS generator with externalization and short interval replacement of the entire system without any break in anti-seizure therapy.

Leveraging ChatGPT in the Pediatric Neurology Clinic: Practical Considerations for Use to Improve Efficiency and Outcomes

BACKGROUND

Artificial intelligence (AI) is progressively influencing healthcare sectors, including pediatric neurology. This paper aims to investigate the potential and limitations of using ChatGPT, a large language model (LLM) developed by OpenAI, in an outpatient pediatric neurology clinic. The analysis focuses on the tool's capabilities in enhancing clinical efficiency, productivity, and patient education.

METHOD

This is an opinion-based exploration supplemented with practical examples. We assessed ChatGPT's utility in administrative and educational tasks such as drafting medical necessity letters and creating patient educational materials.

RESULTS

ChatGPT showed efficacy in streamlining administrative work, particularly in drafting administrative letters and formulating personalized patient education materials. However, the model has limitations in performing higher-order tasks like formulating nuanced differential diagnoses. Additionally, ethical and legal concerns, including data privacy and the potential dissemination of misinformation, warrant cautious implementation.

CONCLUSIONS

The integration of AI tools like ChatGPT in pediatric neurology clinics has demonstrated promising results in boosting efficiency and patient education, despite present limitations and ethical concerns. As technology advances, we anticipate future applications may extend to more complex clinical tasks like precise differential diagnoses and treatment strategy guidance. Careful, patient-centered implementation is essential for leveraging the potential benefits of AI in pediatric neurology effectively.

Use of video alone for differentiation of epileptic seizures from non-epileptic spells: A systematic review and meta-analysis

INTRODUCTION

Review of videos (without electroencephalography) to differentiate epileptic seizures (ES) from non-epileptic spells (NES) may be helpful where epilepsy monitoring is not feasible. Previous studies of video-based diagnosis have suffered from variable accuracy, sensitivity, and specificity.

METHODS

We systematically reviewed relevant literature in PubMed, Embase, and Web of Science from inception to September 2022, identifying articles that reported on the video-based diagnosis of ES and NES. In primary analysis, for each study, the most expert group was chosen when different groups of reviewers classified the videos (e.g., epilepsy specialists and general neurologists). In secondary analysis, we compared the diagnostic accuracy of different expertise levels (e.g., epileptologists, general neurologists, residents, medical students). Meta-analysis was performed to obtain pooled estimates of reliability measures.

RESULTS

From 5245 articles identified, 13 met the inclusion criteria, with cumulative data from 683 patients (696 videos) reviewed by 95 independent reviewers in primary analysis. Video alone had a strong ability to differentiate ES from NES as evidenced by the following metrics- area under the curve- 0.9 (considered "outstanding"), sensitivity- 82.2% (95% Confidence Interval [C.I], 80.2%-84.0%), specificity- 84.7% (C.I., 82.8%-86.5%), and diagnostic odds ratio- 24.7 (C.I., 11.5-52.9). The secondary analysis showed reviewer-dependent accuracy with epileptologists showing the highest accuracy (DOR 81.2, C.I., 90.0%-94.6%).

CONCLUSIONS

Video alone has reliable diagnostic performance for differentiating ES from NES. Meta-analysis limitations include inter-study heterogeneity including variable video quality and reviewer expertise. Combined video-EEG remains the gold standard for the diagnosis of epilepsy and NES.

Responsive Neurostimulation for the Treatment of Children With Drug-Resistant Epilepsy in Tuberous Sclerosis Complex

BACKGROUND

To review seizure outcomes in children with tuberous sclerosis complex (TSC) and drug-resistant epilepsy (DRE) treated with the responsive neurostimulation (RNS) System.

METHODS

We retrospectively reviewed children (<21 years old) with TSC implanted with the RNS System at Texas Children's Hospital between July 2016 and May 2022.

RESULTS

Five patients meeting the search criteria were identified (all female). The median age of the RNS implantation was 13 years (range: 5 to 20 years). The median epilepsy duration before the RNS implantation was 13 years (range: 5 to 20 years). Surgeries before RNS implantation included vagus nerve stimulator placement (n = 2), left parietal resection (n = 1), and corpus callosotomy (n = 1). The median number of antiseizure medications tried before RNS was 8 (range: 5 to 12). The rationale for the RNS System implantation included seizure onset in eloquent cortex (n = 3) and multifocal seizures (n = 2). The maximum current density for each patient ranged between 1.8 and 3.5 μC/cm², with an average daily stimulation of 2240 (range: 400 to 4200). There was an 86% median seizure reduction (range 0% to 99%) at a median follow-up duration of 25 months (range: 17 to 25 months). No patient experienced implantation or stimulation-related complications.

CONCLUSIONS

We observed a favorable improvement in seizure frequency in pediatric patients with DRE secondary to TSC treated with the RNS System. The RNS System may be a safe and effective treatment for DRE in children with TSC.

Seizure control during spontaneous battery failure with responsive neurostimulation

OBJECTIVE

We examined seizure control during spontaneous responsive neurostimulation (RNS) battery failure to investigate the persistent benefits of RNS in the absence of neurostimulation. We hypothesized that the loss of direct RNS does not immediately result in seizure worsening.

METHODS

Patients with RNS battery failure between August 2019 and December 2020 at a single institution were studied. During periods of battery depletion, the RNS device does not store any electrocorticography records, so we used a telephone-based survey and chart review to assess seizure control during battery depletion.

RESULTS

Eight of 10 eligible participants responded to the survey, with a mean duration of battery failure of 36 days (range: 10-219 days). During battery depletion, one patient reported decreased seizures and five reported no changes in seizure frequency. Only two patients reported increased seizure frequency.

SIGNIFICANCE

The benefits of RNS treatment may outlast the immediate effects of direct neurostimulation, lending support to the notion of persistent neuroplasticity. Larger studies should confirm our preliminary findings.

Responsive Neurostimulation in Drug-Resistant Pediatric Epilepsy: Findings From the Epilepsy Surgery Subgroup of the Pediatric Epilepsy Research Consortium

BACKGROUND

Responsive neurostimulation (RNS), a closed-loop intracranial electrical stimulation system, is a palliative surgical option for patients with drug-resistant epilepsy (DRE). RNS is approved by the US Food and Drug Administration for patients aged ≥18 years with pharmacoresistant partial seizures. The published experience of RNS in children is limited.

METHODS

This is a combined prospective and retrospective study of patients aged ≤18 years undergoing RNS placement. Patients were identified from the multicenter Pediatric Epilepsy Research Consortium Surgery Registry from January 2018 to December 2021, and additional data relevant to this study were retrospectively collected and analyzed.

RESULTS

Fifty-six patients received RNS during the study period. The mean age at implantation was 14.9 years; the mean duration of epilepsy, 8.1 years; and the mean number of previously trialed antiseizure medications, 4.2. Five patients (9%) previously trialed dietary therapy, and 19 patients (34%) underwent prior surgery. Most patients (70%) underwent invasive electroencephalography evaluation before RNS implantation. Complications occurred in three patients (5.3%) including malpositioned leads or transient weakness. Follow-up (mean 11.7 months) was available for 55 patients (one lost), and four were seizure-free with RNS off. Outcome analysis of stimulation efficacy was available for 51 patients: 33 patients (65%) were responders (≥50% reduction in seizure frequency), including five patients (10%) who were seizure free at follow-up.

CONCLUSIONS

For young patients with focal DRE who are not candidates for surgical resection, neuromodulation should be considered. Although RNS is off-label for patients aged <18 years, this multicenter study suggests that it is a safe and effective palliative option for children with focal DRE.

Child Neurology: Hemiconvulsion-Hemiplegia-Epilepsy Syndrome in the Setting of COVID-19 Infection and Multisystem Inflammatory Syndrome

Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome is a rare pediatric epilepsy syndrome characterized by prolonged focal febrile convulsive status epilepticus with unilateral hemispheric cerebral edema, followed by the subsequent development of hemiplegia, global atrophy of the affected hemisphere, and epilepsy. The pathophysiology of HHE syndrome remains poorly understood though is clearly multifactorial. Factors thus far implicated are hyperthermia, proinflammatory state, and cytotoxic edema from prolonged ictal activity. Prognosis is variable, from the resolution of hemiplegia and seizures to permanent hemiparesis and refractory epilepsy. We describe a 2-year-old boy who presented with superrefractory focal status epilepticus in the setting of acute coronavirus infectious disease-2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C). He had right-sided hemiplegia on neurologic examination, and an MRI examination of the brain showed left cerebral hemispheric edema consistent with HHE syndrome. Our case represents the first report in the literature on HHE syndrome in the setting of acute COVID-19 and MIS-C.

Predictive value of video alone in diagnosis of epileptic vs paroxysmal nonepileptic events in children

OBJECTIVE

Previous studies examined the use of video-based diagnosis and the predictive value of videos for differentiation of epileptic seizures (ES) from paroxysmal nonepileptic events (PNEE) in the adult population. However, there are no such published studies strictly on the pediatric population. Using video-EEG diagnosis as a gold standard, we aimed to determine the diagnostic predictive value of videos of habitual events with or without additional clinical data in differentiating the PNEE from ES in children.

METHODS

Consecutive admissions to our epilepsy monitoring unit between June 2020 and December 2020 were analyzed for events of interest. Four child neurologists blinded to the patient's diagnosis formulated a diagnostic impression based upon the review of the video alone and again after having access to basic clinical information, in addition to the video. Features of the video which helped to make a diagnosis were identified by the reviewers as a part of a survey.

RESULTS

A total of 54 patients were included (ES n = 24, PNEE n = 30). Diagnostic accuracy was calculated for each reviewer and combined across all the ratings. Diagnostic accuracy by video alone was 74.5% (sensitivity 80.8%, specificity 66.7%). Providing reviewers with basic clinical information in addition to the videos significantly improved diagnostic accuracy compared to viewing the videos alone. Inter-rater reliability between four reviewers based on the video alone showed moderate agreement (κ = 0.51) and unchanged when additional clinical data were presented (κ = 0.51). The ES group was significantly more likely to demonstrate changes in facial expression, generalized stiffening, repetitive eye blinks, and eye deviation when compared with the PNEE group, which was more likely to display bilateral myoclonic jerking.

CONCLUSIONS

Video review of habitual events by Child Neurologists may be helpful in reliably distinguishing ES from PNEE in children, even without included clinical information.

Sub-scalp electroencephalography: A next-generation technique to study human neurophysiology

Sub-scalp electroencephalography (ssEEG) is emerging as a promising technology in ultra-long-term electroencephalography (EEG) recordings. Given the diversity of devices available in this nascent field, uncertainty persists about its utility in epilepsy evaluation. This review critically dissects the many proposed utilities of ssEEG devices including (1) seizure quantification, (2) seizure characterization, (3) seizure lateralization, (4) seizure localization, (5) seizure alarms, (6) seizure forecasting, (7) biomarker discovery, (8) sleep medicine, and (9) responsive stimulation. The different ssEEG devices in development have individual design philosophies with unique strengths and limitations. There are devices offering primarily unilateral recordings (24/7 EEG^TM SubQ, Neuroview^TM, Soenia® UltimateEEG™), bilateral recordings (Minder™, Epios™), and even those with responsive stimulation capability (EASEE®). We synthesize the current knowledge of these ssEEG systems. We review the (1) ssEEG devices, (2) use case scenarios, (3) challenges and (4) suggest a roadmap for ideal ssEEG designs.

Seizure control during the COVID-19 pandemic: Correlating Responsive Neurostimulation System data with patient reports

Objective

To understand the impact of the Coronavirus Disease-2019 (COVID-19) pandemic on seizure frequency in persons with epilepsy with a Responsive Neurostimulation (RNS) system implanted.

Methods

Weekly long episode counts (LEC) were used as a proxy for seizures for six months pre-COVID-19 and during the COVID-19 period. Telephone surveys and chart reviews were conducted to assess patient mental health during the pandemic. The change in LEC between the two time periods was correlated to reported stressors.

Results

Twenty patients were included. Comparing the pre-COVID-19 period to the COVID-19 period, we found that only 5 (25%) patients had increased seizures, which was positively correlated with change in anti-seizure medications (ASM, p = 0.03) and bitemporal seizures (p = 0.03). Increased seizures were not correlated to anxiety (p = 1.00), depression (p = 0.58), and sleep disturbances (p = 1.00). The correlation between RNS-detected and patient-reported seizures was poor (p = 0.32).

Conclusions

Most of our patients did not have an increase in seizures following the COVID-19 pandemic. Changes in ASM and bitemporal seizures were positively correlated to increased LEC. There was no correlation between pandemic-related stress and seizures in those found to have increased seizures.

Significance

This is the first study correlating RNS-derived objective LECs with patient self-reports and potential seizure risk factors during the COVID-19 pandemic.

Comparison of Surgical Outcomes in Individuals With Hypothalamic Hamartoma Alone or With Other Potentially Epileptogenic Focal Lesions

BACKGROUND

Hypothalamic hamartoma is a rare condition associated with refractory seizures. It can occur in isolation or with additional epileptogenic lesions. The aim of this study was to investigate the effects of additional potentially epileptogenic lesions on surgical outcomes in individuals with hypothalamic hamartoma.

METHODS

We conducted a chart review of 112 patients with hypothalamic hamartoma who underwent magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy targeted to the hypothalamic hamartoma. We compared surgical outcomes after at least six months of postoperative follow-up (N = 65) between patients with hypothalamic hamartoma alone and those with hypothalamic hamartoma plus additional potentially epileptogenic lesions.

RESULTS

Sixteen out of 112 (14%) patients had additional epileptogenic lesions, including focal cortical dysplasia, gray matter heterotopia, and polymicrogyria. Ten out of 16 patients with additional lesions and 55 out of 96 patients with hypothalamic hamartoma alone had more than six months of follow-up and are included in the outcome analysis. Mean follow-up in these patients is 21.5 ± 17.3 months (standard deviation, range: 7.3-76.8 months) for patients with hypothalamic hamartoma alone and 16.1 ± 15.0 months (standard deviation, range: 6.6-58.2 months) for those with hypothalamic hamartoma plus additional epileptogenic lesions. Fewer patients with hypothalamic hamartoma plus other lesions had Engel class I/II outcomes than patients with hypothalamic hamartoma alone (5/10 [50%] vs 46/55 [83.6%]; P = 0.031).

CONCLUSIONS

MRI-guided laser interstitial thermal therapy remains an effective treatment option for patients with hypothalamic hamartoma. However, the outcome of surgical procedures targeted to the hypothalamic hamartoma may be less favorable in patients who have hypothalamic hamartoma coexisting with other potentially epileptogenic focal lesions. Thus, an additional surgical workup is warranted for these patients who have failed surgical treatment of hypothalamic hamartoma.

Clinical Profile and Long-Term Outcomes in Pediatric Cavernous Sinus Thrombosis

BACKGROUND

Pediatric cavernous sinus thrombosis (CST) is a rare condition with limited data regarding its clinical characteristics and long-term outcomes. The objective of this study was to describe the clinical and radiologic features, diagnostic evaluation, management, and long-term prognosis and to identify clinical variables associated with long-term outcomes in pediatric CST.

METHODS

A retrospective chart review of patients younger than 18 years diagnosed with a CST between 2004 and 2018 at a single center was conducted.

RESULTS

We identified 16 (M:F = 10:6) children with CST with a mean age of 7.6 years (10 days to 15 years) and average follow-up duration of 29 months (3 weeks to 144 months). The most common symptom and examination finding at presentation was eyelid swelling (n = 8). Six patients had bilateral CST. The most common etiologies were sinusitis (n = 5) and orbital cellulitis (n = 5). Treatments included antibiotics (n = 14), anticoagulation (n = 11), and surgery (n = 5). Only one patient died due to intracranial complications. Twelve patients had a normal examination at follow-up. None of the clinical variables including age (P = 0.14), gender (P = 0.09), use of antibiotics (P = 1.00) or anticoagulation (P = 1.00), surgery (P = 0.28), parenchymal abnormalities (P = 0.30), additional cerebral venous thrombosis (P = 0.28), and early versus late commencing of anticoagulation (P = 1.00) were significant when comparing patients with full/partial resolution versus those with no resolution of thrombosis on follow-up neuroimaging.

CONCLUSIONS

Our study is one of the largest cohorts with the longest follow-up data for the pediatric CST. Most of our patients had favorable outcomes at follow-up. We found no statistical difference between clinical variables when comparing patients with full/partial resolution versus those with no resolution of thrombosis on follow-up neuroimaging.

Frequency, Predictors, and Outcome of Seizures in Patients With Myelomeningocele: Single-Center Retrospective Cohort Study

To determine the frequency, predictors, and outcomes of seizures in patients with myelomeningocele, we retrospectively analyzed the data from patients with myelomeningocele followed longitudinally at a single center from 1975 to 2013. We identified a total of 122 patients (61% female). The mean follow-up duration was 11.1 years (minimum-maximum = 0-34.5 years, SD = 8.8, median = 9.1 years). A total of 108 (88.5%) patients had hydrocephalus, and 98 (90.7%) of those patients required a ventriculoperitoneal shunt procedure. Twenty-four (19.7%) patients manifested with seizures, 23 of whom had hydrocephalus. The average age of seizure onset was 4.8 years (median 2 years of age). Falx dysgenesis (P = .004), lumbar myelomeningocele (P = .007), and cortical atrophy (P = .028) were significantly associated with epileptic seizure development. The average seizure-free period at the last follow-up in patients with a history of myelomeningocele and seizures was 8.1 years. We conclude that myelomeningocele patients with seizures have an overall good prognosis with considerable long-term seizure freedom.

Epileptic Spasms in a Large Hypothalamic Hamartoma Cohort

INTRODUCTION

Hypothalamic hamartoma is rarely associated with epileptic spasms. We describe epileptic spasms in a large cohort of hypothalamic hamartoma patients.

METHODS

We performed a retrospective chart review between March 2011 and March 2020 to identify patients with hypothalamic hamartoma and epilepsy.

RESULTS

We identified 114 patients with hypothalamic hamartoma and epilepsy, only 3 male patients (2.6%) also had epileptic spasms. The epileptic spasms developed between 6 and 18 months of age. Epileptic spasms resolved with oral prednisolone in 1 and with vigabatrin in the second patient. The third patient continued epileptic spasms despite multiple antiepileptic drugs and partial resection of hypothalamic hamartoma. All 3 patients underwent laser-ablation of hypothalamic hamartoma at the age of 14, 29, and 63 months. The seizure burden decreased by 100%, 84%, and 93% at follow-up (3-47 months).

CONCLUSIONS

Epileptic spasms are rare in hypothalamic hamartoma patients and early laser-ablation could potentially treat epileptic spasms and all other seizure types associated with hypothalamic hamartoma.

Challenges in the Transition of Care Process for Patients with Dravet and Lennox–Gastaut Syndromes

Epileptic encephalopathies such as Dravet syndrome (DS) and Lennox–Gastaut syndrome (LGS) present unique challenges in the transition of care not only for the providers but also for the patients and families. Some of these challenges include the complexity of disease process, differences in medication management between children and adults, high incidence of comorbidities such as psychosocial issues, a lack of structured transition process from pediatric to adult care, and the lack of parental knowledge and reluctance to transition to an adult provider. Improving transition readiness and transfer of care are essential to long-term management and continuity of care. Studies show that patients/families who possess transition readiness skills have better health outcomes. Furthermore, participation in a structured transition intervention has been shown to improve transition readiness and utilization of ambulatory care in the adult setting. Reported benefits of implementation of transition planning include increased self-esteem, improved health literacy, fewer emergency room visits, decreased hospitalizations and comorbidities, and fewer school absences. Nevertheless, there is a lack of evidenced-based, family/patient-centered transition model of care. This review's primary goal is to provide an overview of challenges in the transition of care and recommendations for an ideal transition for patients with DS and LGS.

Metabolomics of mammalian brain reveals regional differences

Background

The mammalian brain is organized into regions with specific biological functions and properties. These regions have distinct transcriptomes, but little is known whether they may also differ in their metabolome. The metabolome, a collection of small molecules or metabolites, is at the intersection of the genetic background of a given cell or tissue and the environmental influences that affect it. Thus, the metabolome directly reflects information about the physiologic state of a biological system under a particular condition. The objective of this study was to investigate whether various brain regions have diverse metabolome profiles, similarly to their genetic diversity. The answer to this question would suggest that not only the genome but also the metabolome may contribute to the functional diversity of brain regions.

Methods

We investigated the metabolome of four regions of the mouse brain that have very distinct functions: frontal cortex, hippocampus, cerebellum, and olfactory bulb. We utilized gas- and liquid- chromatography mass spectrometry platforms and identified 215 metabolites.

Results

Principal component analysis, an unsupervised multivariate analysis, clustered each brain region based on its metabolome content, thus providing the unique metabolic profile of each region. A pathway-centric analysis indicated that olfactory bulb and cerebellum had most distinct metabolic profiles, while the cortical parenchyma and hippocampus were more similar in their metabolome content. Among the notable differences were distinct oxidative-anti-oxidative status and region-specific lipid profiles. Finally, a global metabolic connectivity analysis using the weighted correlation network analysis identified five hub metabolites that organized a unique metabolic network architecture within each examined brain region. These data indicate the diversity of global metabolome corresponding to specialized regional brain function and provide a new perspective on the underlying properties of brain regions.

Conclusion

In summary, we observed many differences in the metabolome among the various brain regions investigated. All four brain regions in our study had a unique metabolic signature, but the metabolites came from all categories and were not pathway-centric.

Electronic supplementary material

The online version of this article (10.1186/s12918-018-0644-0) contains supplementary material, which is available to authorized users.

Quantitative Assessment of HER-2/Neu Protein Concentration in Breast Cancer by Enzyme-Linked Immunosorbent Assay

Purpose

The HER-2/neu protein (p185) has become a promising target for antibody therapy in breast cancer. We tested the feasibility of a quantitative approach for HER-2/neu testing based on the analysis of tumor tissue extracts by an enzyme-linked immunosorbent assay (ELISA).

Experimental design

Tumor tissue extracts of primary human breast cancers (n=124) were prepared using a triton-based buffer. HER-2/neu concentration was quantified by ELISA. Paraffin-embedded tissue sections of the same tumors were analyzed by immunohistochemical staining applying the monoclonal HER-2/neu antibody TAB 250 (n=124) and by chromogenic in situ hybridization (CISH) (n=73).

Results

Concentrations of p185 in tissue extracts determined by ELISA varied from 1 to 927 ng per mg protein with a median of 25 ng/mg protein, whereas normal breast tissue showed values from 0.4 to 5.5 ng/mg with a median of 2.2 ng/mg (p<0.0001, Mann-Whitney U test). A significant correlation between p185 concentration and immunohistochemical staining was observed (p<0.0001, Kruskal-Wallis test). In addition, p185 concentration measured by ELISA was correlated with the degree of HER-2/neu gene amplification determined by CISH. HER-2/neu-amplified tumors had significantly higher p185 concentrations (median value 181 ng/mg protein) than non-amplified tumors (median value 20 ng/mg; p<0.0001, Mann-Whitney U test).

Conclusions

ELISA-based measurement of HER-2/neu protein concentration in breast cancer tissue extracts is feasible and provides quantitative results for p185 protein concentrations that correlate closely with HER-2/neu immunoscore and gene amplification.

Abstract P5-04-03: Palbociclib synergizes with autophagy inhibitors to induce senescence in breast cancer

This abstract was withdrawn by the authors.

Abstract P6-12-09: Targeting deregulated cyclin E in inflammatory breast cancer via sequential combination therapy

Inflammatory breast cancer (IBC) is a rare, highly aggressive form of breast cancer, accounting for 2-5% of all breast cancers in the US and 10% of breast cancer deaths. Unfortunately, until recently this disease has not been studied extensively at the molecular/cellular level despite the compelling unmet need to develop more effective therapies. In spite of receiving aggressive multidisciplinary therapy (anthracycline-taxane-based neoadjuvant chemotherapy, modified-radical-mastectomy and adjuvant radiation therapy), only about 40% of IBC patients survive 5 years. The goal of this project is to identify new targets that can be exploited pharmacologically either in combination with current therapies or with other novel agents.

Previous work has identified tumor-specific low molecular weight forms of cyclin E, termed LMW-E, that are preferentially found in triple negative breast cancers (TNBC) and serve as a poor prognostic biomarker. As a result of cleavage, LMW-E preferentially accumulates in the cytoplasm where it exerts its pleiotropic oncogenic functions including deregulating the cell cycle. Furthermore, we have shown that TNBC cells harboring LMW-E are sensitive to CDK inhibitors.

To establish the clinical relevance of targeting the cyclin E/CDK2 axis in IBC, a pilot study was performed to determine the incidence of LMW-E. We performed IHC on 11 post-chemotherapy surgical specimens from MDACC. All tumors expressed cyclin E, 8 of which had predominantly cytoplasmic staining, indicative of LMW-E expression. These results are now being validated in a larger cohort of samples. These promising preliminary results led us to perform in vitro experiments to determine sensitivity to CDK2 inhibitors and characterize cell cycle profiles.

Similar to non-IBC breast cancers, IBC tumors can be ER-positive, TNBC or HER2-overexpressing; however, there are only TN-IBC or HER2+ cell lines. We utilized 2 cell lines for these studies, one of which is TN-IBC, the other of which is ER-negative and HER2-overexpressing. These cell lines were treated with a panel of CDK inhibitors to evaluate their sensitivity in both short-term and long-term assays. The long-term assay we developed called the high-throughput survival assay was used to examine combinations of agents for potential synergies using isobologram analysis. We have demonstrated chemotherapy-specific synergistic cell death when cells are first treated with CDK inhibitor in IBC and non-IBC cell lines.

Using flow cytometry, we have demonstrated that CDK inhibitors induce a G2/M arrest, which is further increased by sequential treatment with chemotherapy. Furthermore, combination treatment leads to cell death, as measured by sub-G1 DNA content.

Taken together, these studies provide solid evidence that targeting CDK2 is a promising strategy in treating IBC tumors that express cyclin E. Beyond these early pre-clinical advances, however, we demonstrated clear sequence-specificity for certain pairs of drugs, implying that future clinical studies should be designed taking into account the mechanism of action of cell cycle targeting drugs.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-12-09.

P5-03-01: Cytoplasmic Cyclin E and P-CDK2 Expression in Triple Negative Breast Carcinomas Measured by Immunohistochemistry Correlates with Poor Outcome

Background: Triple negative breast carcinomas (TNBCs) are aggressive malignancies that lack effective therapeutic targets but express low molecular isoforms of cyclin E (LMW-E). These LMW-E, generated primarily from NH2-terminal elastase cleavage of full length cyclin E (EL), preferentially accumulate in the cytoplasm of cancer cells. Using a transgenic mouse model system, our laboratory has recently shown that cyclin-dependent kinase 2 (CDK2) is required for LMW-E-mediated mammary tumorigenesis. These results lead us to hypothesize that immunohistochemical cytoplasmic detection of LMW-E and phospho-CDK2 in TNBC provides a valuable screening tool for those patients most likely to have a poor prognosis who could then be treated with anti-CDK2 therapy currently clinically available. Material and Methods: Tissue micro-arrays from 168 TNBC patients were IHC stained for cyclin E and p-CDK2. Cyclin E staining intensity and percentage of positivity were evaluated both in the nucleus and cytoplasm of cancer cells and four different phenotypes of cyclin E were distinguished with respect to predominant nuclear or cytoplasmic localization of staining: cyclin E negative, predominantly nuclear, both nuclear and cytoplasmic and predominantly cytoplasmic. p-CDK2 IHC was achived using an antibody, which recognizes phospho-threonine 160 on CDK2. Immunoreactive scores were determined by multiplying the intensity with the extent of staining of nuclei and cytoplasm. We sought correlations between different cyclin E and p-CDK2 expression patterns and disease-free survival (DFS). Results: Cytoplasmic cyclin E accumulation on IHC of TNBCs correlated with poor outcome. Within the median follow up of 7.3 years tumors with both nuclear and cytoplasmic cyclin E expression demonstrated higher recurrence rate compared to entirely negative for cyclin E (p=0.0117). In contrast patients with exclusively nuclear cyclin E showed only a trend toward decreased DFS compared to patients with cyclin E negative tumors (p=0.0896). Furthermore we identified the new phenotype of cyclin E immunoreactivity, which is characterized by negative nucleus and positive cytoplasmic staining. This phenotype was the most significantly associated with poor DFS compared to cyclin E negative phenotype (p=0.0026) and as the only one distinguished at high risk of early recurrence among TNBC patient without axillary nodes involvement (p=0.0105). The expression of p-CDK2 was significantly higher in this phenotype than the cytoplasmic cyclin E.negative tumors. High p-CDK2 tumors were also correlated to worse DFS then p-CDK2 low tumors (P=0.019). Lastly, our analyses revealed that tumors positive for both cytoplasmic cyclin E and p-CDK2 had higher recurrence rate compared to negative for both or positive for one of them (p=0.003).

Discussion: Cytoplasmic cyclin E may help to predict recurrence, especially in early stage, node negative TNBCs. We present a new concept in assessing cyclin E expression. Poor outcome due to TNBCs overexpressing LMW-E provide a rationale to investigate the treatment strategies that could specifically target high LMW-E tumors. These patients could particularly benefit from treatment with CDK2 inhibitors.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-03-01.