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.

US Generic Antiseizure Medication Supply Chain: Observations from Analysis of US Government Databases.

BACKGROUND: Generic drug manufacturing has shifted away from the U.S. in the last few decades. The medication supply chain, from manufacturers to resellers, has become increasingly globalized and complex. This has led to bottlenecks in their manufacture resulting in medication shortages. Review of this process as it pertains to antiseizure medications (ASM) shows gaps in our comprehension of its complexities. Understanding these processes will be essential for preventing medication shortages. OBJECTIVES: The aim of this research is to examine the generic ASM supply with an emphasis on production, labeling, and repackaging. METHODS: Data from the United States Food and Drug Administration (FDA) and the National Library of Medicine (NLM) website DailyMed was used to evaluate supply chain details to gather information on antiseizure medication formulations, manufacturing locations, and labeling. RESULTS: Out of 3142 ASM-related active National Drug Code (NDC-9) codes, 2663 NDC-9 codes with Abbreviated New Drug Application (ANDA) status were included in the analysis. Most (94.8 %) were enteral, with only 5.2 % being parenteral (intravenous and intramuscular route). We identified the manufacturing country for 82 % of these codes, corresponding to 306 unique ANDA numbers. 119 manufacturing sites in 12 countries produce generic ASM Finished Dosage Forms (FDF): 103 for enteral and 21 for parenteral. India is the main producer of enteral ASM FDFs with 49 sites, followed by the US with 36. Regarding parenteral formulation, five countries had 21 unique manufacturing locations. 42 % of the 103 enteral ASM FDFs manufacturing sites produced multiple ASM FDFs, with one facility making eight distinct ASMs. 34.4 % of facilities were associated with over 3 ANDAs, and 15.1 % with more than 5. 22.7 % of ANDAs lacked a manufacturing facility identifier. Repackaged ASM FDFs constituted 48 % of NDC-9 s. Gabapentin and pregabalin were the most common oral ASMs. CONCLUSIONS: India is the major source for generic ASM FDFs manufacturing, leading to concerns about overall supply dependency on that country. There is a paucity of facilities for the global supply of parenteral ASM FDFs. There is missing data for many NDC-9 codes emphasizing urgency for transparency in the supply chain.

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.

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.

Papilledema in Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP): A Pediatric Case and Review of the Literature.

OBJECTIVE: To analyze the available literature on papilledema in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), report the first detailed pediatric case, and explore the underlying pathophysiology. METHODS: First, we conducted a comprehensive literature review of all cases of papilledema in CIDP. Next, we reviewed each case, incorporating only those including cerebrospinal fluid analysis into the results. Finally, we present our pediatric patient. RESULTS: Our literature review yielded a total of 9 adult and no pediatric cases. Cerebrospinal fluid protein and opening pressures were elevated in all cases. They were also elevated in our pediatric case. CONCLUSION: Prolonged periods of active immune-mediated inflammation is likely a cause of papilledema in adult CIDP, and possibly also in our pediatric case.