TMEM161B regulates cerebral cortical gyration, Sonic Hedgehog signaling, and ciliary structure in the developing central nervous system.

Sonic hedgehog signaling regulates processes of embryonic development across multiple tissues, yet factors regulating context-specific Shh signaling remain poorly understood. Exome sequencing of families with polymicrogyria (disordered cortical folding) revealed multiple individuals with biallelic deleterious variants in TMEM161B, which encodes a multi-pass transmembrane protein of unknown function. Tmem161b null mice demonstrated holoprosencephaly, craniofacial midline defects, eye defects, and spinal cord patterning changes consistent with impaired Shh signaling, but were without limb defects, suggesting a CNS-specific role of Tmem161b. Tmem161b depletion impaired the response to Smoothened activation in vitro and disrupted cortical histogenesis in vivo in both mouse and ferret models, including leading to abnormal gyration in the ferret model. Tmem161b localizes non-exclusively to the primary cilium, and scanning electron microscopy revealed shortened, dysmorphic, and ballooned ventricular zone cilia in the Tmem161b null mouse, suggesting that the Shh-related phenotypes may reflect ciliary dysfunction. Our data identify TMEM161B as a regulator of cerebral cortical gyration, as involved in primary ciliary structure, as a regulator of Shh signaling, and further implicate Shh signaling in human gyral development.

Multimodal mapping of regional brain vulnerability to focal cortical dysplasia.

Focal cortical dysplasia (FCD) type II is a highly epileptogenic developmental malformation and a common cause of surgically treated drug-resistant epilepsy. While clinical observations suggest frequent occurrence in the frontal lobe, mechanisms for such propensity remain unexplored. Here, we hypothesized that cortex-wide spatial associations of FCD distribution with cortical cytoarchitecture, gene expression and organizational axes may offer complementary insights into processes that predispose given cortical regions to harbour FCD. We mapped the cortex-wide MRI distribution of FCDs in 337 patients collected from 13 sites worldwide. We then determined its associations with (i) cytoarchitectural features using histological atlases by Von Economo and Koskinas and BigBrain; (ii) whole-brain gene expression and spatiotemporal dynamics from prenatal to adulthood stages using the Allen Human Brain Atlas and PsychENCODE BrainSpan; and (iii) macroscale developmental axes of cortical organization. FCD lesions were preferentially located in the prefrontal and fronto-limbic cortices typified by low neuron density, large soma and thick grey matter. Transcriptomic associations with FCD distribution uncovered a prenatal component related to neuroglial proliferation and differentiation, likely accounting for the dysplastic makeup, and a postnatal component related to synaptogenesis and circuit organization, possibly contributing to circuit-level hyperexcitability. FCD distribution showed a strong association with the anterior region of the antero-posterior axis derived from heritability analysis of interregional structural covariance of cortical thickness, but not with structural and functional hierarchical axes. Reliability of all results was confirmed through resampling techniques. Multimodal associations with cytoarchitecture, gene expression and axes of cortical organization indicate that prenatal neurogenesis and postnatal synaptogenesis may be key points of developmental vulnerability of the frontal lobe to FCD. Concordant with a causal role of atypical neuroglial proliferation and growth, our results indicate that FCD-vulnerable cortices display properties indicative of earlier termination of neurogenesis and initiation of cell growth. They also suggest a potential contribution of aberrant postnatal synaptogenesis and circuit development to FCD epileptogenicity.

Seizure control in women with epilepsy undergoing assisted reproductive technology.

The objective of this study was to determine seizure control in women with epilepsy (WWE) undergoing assisted reproductive technology (ART). Through retrospective chart review, WWE undergoing ART were identified. Demographics and details regarding epilepsy type, seizure control, and ART procedures were extracted. Seizure frequency prior to and during ART were compared. We identified 12 WWE, who underwent 29 embryo transfers, resulting in 16 pregnancies and 10 live births. Nine women were seizure-free at least 2 years before fertility treatment, including three with resolved epilepsy. Seven were on antiseizure medications throughout fertility treatment and pregnancy, with only one on polytherapy. Eleven (all with controlled epilepsy or epilepsy in remission) remained seizure-free throughout fertility treatment. One woman with drug-resistant epilepsy continued to have seizures throughout fertility treatment and pregnancy without an exacerbation of seizure frequency. There was no increased seizure frequency associated with fertility treatment and subsequent pregnancy in this small series of WWE. Although this study was statistically underpowered, our results provide some preliminary evidence that ART might not pose a threat to seizure control, but larger, confirmatory studies are necessary.

Later onset focal epilepsy with roots in childhood: Evidence from early learning difficulty and brain volumes in the Human Epilepsy Project.

OBJECTIVE: Visual assessment of magnetic resonance imaging (MRI) from the Human Epilepsy Project 1 (HEP1) found 18% of participants had atrophic brain changes relative to age without known etiology. Here, we identify the underlying factors related to brain volume differences in people with focal epilepsy enrolled in HEP1. METHODS: Enrollment data for participants with complete records and brain MRIs were analyzed, including 391 participants aged 12-60 years. HEP1 excluded developmental or cognitive delay with intelligence quotient <70, and participants reported any formal learning disability diagnoses, repeated grades, and remediation. Prediagnostic seizures were quantified by semiology, frequency, and duration. T1-weighted brain MRIs were analyzed using Sequence Adaptive Multimodal Segmentation (FreeSurfer v7.2), from which a brain tissue volume to intracranial volume ratio was derived and compared to clinically relevant participant characteristics. RESULTS: Brain tissue volume changes observable on visual analyses were quantified, and a brain tissue volume to intracranial volume ratio was derived to compare with clinically relevant variables. Learning difficulties were associated with decreased brain tissue volume to intracranial volume, with a ratio reduction of .005 for each learning difficulty reported (95% confidence interval [CI] = -.007 to -.002, p = .0003). Each 10-year increase in age at MRI was associated with a ratio reduction of .006 (95% CI = -.007 to -.005, p < .0001). For male participants, the ratio was .011 less than for female participants (95% CI = -.014 to -.007, p < .0001). There were no effects from seizures, employment, education, seizure semiology, or temporal lobe electroencephalographic abnormalities. SIGNIFICANCE: This study shows lower brain tissue volume to intracranial volume in people with newly treated focal epilepsy and learning difficulties, suggesting developmental factors are an important marker of brain pathology related to neuroanatomical changes in focal epilepsy. Like the general population, there were also independent associations between brain volume, age, and sex in the study population.

Functional neurological seizures and migraine: A systematic review and case series.

BACKGROUND: The seizure subtype of functional neurological disorder (FND-seizures) is a common neuropsychiatric condition manifesting with episodic epilepsy-like events. Despite the common belief that FND-seizures are precipitated by psychological stressors, neurological disorders may also be triggers. In 1890, Babinski described four cases of FND symptoms associated with migraine attacks. Despite the passing of more than 130 years since this first clinical observation, the relationship between FND-seizures and migraine is not fully elucidated. OBJECTIVES: (1) To complete a systematic review of the literature that investigated potential associations between FND-seizures and migraine and the response of FND seizures to treatment with migraine prophylactic medications (2). To undertake a retrospective study of patients with FND-seizures and migraine, including response to migraine prophylaxis. METHODS: (1) Using PRISMA methods, we completed a systematic review of EMBASE and Scopus databases from inception to March 31, 2021, for literature on FND-seizures and migraine. (2) Our multi-disciplinary team, including subspecialists in psychosomatic medicine, epilepsy, and headache disorders, reviewed consecutive patients diagnosed with FND-seizures and migraine to assess potential causal associations and responses to standard migraine prophylactic medications. RESULTS: (1) The search yielded seven studies from 126 screened manuscripts (N = 1,186 patients with FND-seizures; mean age 38.7 years; 72.6% female). They varied substantially in design, population, diagnostic measures, and outcomes. Nevertheless, all studies found associations between FND-seizures and migraine, which were stronger than those between epileptic seizures and migraine in comparative investigations, but provided limited information on treatment response. (2) In our case series, investigators reached unanimous consensus that migraine attacks triggered FND-seizures in 28/43 (65.1%) patients reviewed (mean age, 38.8 years; 74% female). In 19/26 (73%) patients with adequate follow-up data, treatment with migraine prophylactic medications alone (no behavioral interventions) concomitantly reduced FND-seizure and headache frequency by >50%. CONCLUSION: Our systematic review and case series indicate that migraine attacks may trigger FND-seizures, perhaps more often that currently understood, and suggest that migraine prophylaxis may reduce FND-seizure frequency in such cases. To validate these observations, fully powered prospective investigations are required.

Drug-resistant temporal lobe epilepsy with temporal encephaloceles: How far to resect.

PURPOSE: This study sought to evaluate the impact of surgical extent on seizure outcome in drug-resistant temporal lobe epilepsy (DR-TLE) with temporal encephaloceles (TE). METHODS: This was a single-institution retrospective study of patients who underwent surgery for DR-TLE with TE between January 2008 and December 2020. The impact of surgical extent on seizure outcome was evaluated. In a subset with dominant DR-TLE, the impact of surgical extent on neuropsychometric outcome was evaluated. RESULTS: Thirty-four patients were identified (female, 56%; median age at surgery, 43 years). TE were frequently overlooked on initial magnetic resonance imaging (MRI), with encephaloceles only detected after repeat or expert re-review of MRI, additional multi-modal imaging, or intra-operatively in 31 (91%). Sixteen (47%) underwent limited resections, including encephalocele resection only (n = 5) and encephalocele resection with more extensive temporal corticectomy sparing the amygdala and hippocampus (n = 11). The remainder (n = 18, 53%) underwent standard anterior temporal lobectomy and amygdalohippocampectomy (ATLAH). Limited resection was performed more frequently on the left (12/17 vs. 4/17, p = 0.015). Twenty-seven patients (79%) had a favourable outcome (Engel I/II), and 17 (50%) were seizure-free at the last follow-up (median seizure-free survival of 27.3 months). There was no statistically significant difference in seizure-free outcomes between limited resection and ATLAH. In dominant DR-TLE, verbal memory decline was more likely after ATLAH than limited resection (3/4 vs. 0/9, p = 0.014). CONCLUSION: Expert re-review of imaging and multi-modal advanced imaging improved TE identification. There was no statistical difference in seizure-free outcomes based on surgical extent. Preservation of verbal memory supports limited resection in dominant temporal cases.

Use of second doses of Valtoco® (diazepam nasal spray) across 24 hours after the initial dose for out-of-hospital seizure clusters: Results from a phase 3, open-label, repeat-dose safety study.

OBJECTIVE: An exploratory analysis from a long-term, phase 3, open-label, repeat-dose safety study of diazepam nasal spray for acute treatment of seizure clusters assessed the use of a second dose up to 24 hours after the initial dose and effectiveness in potentially reducing the number of seizures. METHODS: Seizures and doses were recorded in diaries. RESULTS: Of 175 patients enrolled, 163 received ≥1 dose of diazepam nasal spray and were included in the safety population; those patients received a total of 4390 doses for a total of 3853 seizure clusters. Less than half of these patients used a second dose a least once during the study (79 patients [48.5%]), with a total of 485 second doses for seizure clusters (12.6% of all seizure clusters). Among these 79 patients, 33 (41.8%) used only one second dose during the study (range: 1-82). The proportion of seizure clusters treated with a second dose over time was consistently low across 24 h: 0-4 h, 152 (3.9%); 4-6 h, 72 (1.9%); 6-8 h, 39 (1.0%); 8-12 h, 55 (1.4%); 12-16 h, 42 (1.1%); 16-20 h, 42 (1.1%); 20-24 h, 83 (2.2%). Rates of treatment-emergent adverse events (TEAEs) and treatment-related TEAEs occurring within 1 day of a second dose were low (15.2% and 5.1%, respectively). SIGNIFICANCE: Patients with epilepsy may experience seizure clusters lasting up to 24 hours, and little is known about the effectiveness of rescue therapies for that duration. The current labeling of the US Food and Drug Administration (FDA)-approved outpatient treatments for seizure clusters (rectal diazepam, intranasal midazolam, and diazepam nasal spray) allows for a second dose, if needed, for control. These findings support the safety profile of second doses, and the low use supports the effectiveness of diazepam nasal spray across 24 hours.

Practical considerations in epilepsy neurostimulation.

Neuromodulation is a key therapeutic tool for clinicians managing patients with drug-resistant epilepsy. Multiple devices are available with long-term follow-up and real-world experience. The aim of this review is to give a practical summary of available neuromodulation techniques to guide the selection of modalities, focusing on patient selection for devices, common approaches and techniques for initiation of programming, and outpatient management issues. Vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (DBS-ANT), and responsive neurostimulation (RNS) are all supported by randomized controlled trials that show safety and a significant impact on seizure reduction, as well as a suggestion of reduction in the risk of sudden unexplained death in epilepsy (SUDEP). Significant seizure reductions are observed after 3 months for DBS, RNS, and VNS in randomized controlled trials, and efficacy appears to improve with time out to 7 to 10 years of follow-up for all modalities, albeit in uncontrolled follow-up or retrospective studies. A significant number of patients experience seizure-free intervals of 6 months or more with all three modalities. Number and location of epileptogenic foci are important factors affecting efficacy, and together with comorbidities such as severe mood or sleep disorders, may influence the choice of modality. Programming has evolved-DBS is typically initiated at lower current/voltage than used in the pivotal trial, whereas target charge density is lower with RNS, however generalizable optimal parameters are yet to be defined. Noninvasive brain stimulation is an emerging stimulation modality, although it is currently not used widely. In summary, clinical practice has evolved from those established in pivotal trials. Guidance is now available for clinicians who wish to expand their approach, and choice of neuromodulation technique may be tailored to individual patients based on their epilepsy characteristics, risk tolerance, and preferences.

Lack of clinically relevant differences in safety and pharmacokinetics after second-dose administration of intranasal diazepam within 4 h for acute treatment of seizure clusters: A population analysis.

OBJECTIVE: Current diazepam nasal spray labeling requires waiting 4 h before administering a second dose. The objective of the current analyses was to examine safety and pharmacokinetic profiles of second doses of diazepam nasal spray given 0-4 h after the first dose. METHODS: Two datasets were analyzed. The first, a long-term, repeat-dose safety study of diazepam nasal spray, compared rates of treatment-emergent adverse events (TEAEs), serious TEAEs, and treatment-related TEAEs for patients receiving ≥1 second dose ≤4 h versus all second doses >4 h after the first. The second was a population pharmacokinetic analysis using data from three phase 1 studies to model drug exposure when a second dose of diazepam nasal spray was administered across multiple time points (1 min-4 h) following the first dose. RESULTS: In the repeat-dose safety study, a second dose of diazepam nasal spray was administered ≤24 h after the first to treat 485 seizure clusters in 79 patients. Rates of TEAEs were similar between patients receiving ≥1 second dose in ≤4 h (89.5%, n = 38) compared with >4-24 h only (80.5%, n = 41). The most common treatment-related TEAEs were associated with nasal discomfort, which was mild or moderate and transient. There were no reports of respiratory or cardiac depression. The pharmacokinetic simulations of second doses predicted comparable elevations of plasma diazepam concentrations with administrations across a range of intervals after the first dose (1 min-4 h). SIGNIFICANCE: These data indicate that the safety and pharmacokinetic profiles of a second dose of diazepam nasal spray administered within 4 h of the first dose are consistent with those associated with current labeling. This is potentially important for patients with seizure clusters who have a recurrent seizure within 4 h of first treatment and might benefit from immediate retreatment to reduce the risk of progression to status epilepticus.

Musicogenic epilepsy: Expanding the spectrum of glutamic acid decarboxylase 65 neurological autoimmunity.

The objective of this study was to describe serological association of musicogenic epilepsy and to evaluate clinical features and outcomes of seropositive cases. Through retrospective chart review, musicogenic epilepsy patients were identified. Among 16 musicogenic epilepsy patients, nine underwent autoantibody evaluations and all had high-titer glutamic acid decarboxylase 65-immunoglobulin G (GAD65-IgG; >20 nmol·L-1 , serum, normal ≤ .02 nmol·L-1 , eight women). Median GAD65-IgG serum titer was 294 nmol·L-1 (20.3-3005 nmol·L-1 ), and median cerebrospinal fluid titer (n = 4) was 14.7 nmol·L-1 . All patients had temporal lobe epilepsy, and bitemporal epileptiform abnormalities were common. Right temporal lobe seizures were most frequently captured when seizures were induced by music on electroencephalogram (3/4; 75%). Intravenous (IV) methylprednisolone and/or IV Ig (IVIG) was utilized in four patients, with one having greater than 50% reduction. Rituximab (n = 2) and mycophenolate (n = 1) were ineffective. Two patients underwent right temporal lobe resections but continued to have seizures. Vagus nerve stimulation was effective at reducing seizures in one patient by 50%, and an additional patient was seizure-free by avoiding provoking music. Right temporal lobe epilepsy was more common among patients with musicogenic epilepsy when compared to nonmusicogenic GAD65 epilepsies (n = 71, 89% vs. 47%, p = .03). GAD65-IgG should be tested in patients with musicogenic epilepsy, given implications for management and screening for comorbid autoimmune conditions.

Evaluation of diazepam nasal spray in patients with epilepsy concomitantly using maintenance benzodiazepines: An interim subgroup analysis from a phase 3, long-term, open-label safety study.

OBJECTIVE: Diazepam nasal spray (Valtoco), indicated for acute treatment of frequent seizure activity (seizure clusters) in patients with epilepsy ≥6 years of age, is designed to be a rapid, noninvasive, socially acceptable route of administration. This interim analysis evaluated the safety profile of diazepam nasal spray in patients with and without concomitant use of benzodiazepines, with use of a second dose for a seizure cluster as a proxy for effectiveness. METHODS: A long-term, phase 3, open-label safety study enrolled patients with epilepsy who had seizures despite a stable antiseizure medication regimen. RESULTS: Among 175 patients enrolled by October 31, 2019, a total of 158 were treated with diazepam nasal spray (aged 6-65 years; 53.8% female). Of those, 119 (75.3%) received concomitant benzodiazepines (60, chronic; 59, intermittent); 39 (24.7%) did not. Use of a second dose was similar in patients using chronic concomitant benzodiazepines (second dose in 11.1% [144/1299]) and those with no concomitant benzodiazepines (second dose in 10.3% [41/398]). Treatment emergent adverse events (TEAEs) occurred for 80.0% with chronic use of concomitant benzodiazepines and 61.5% without. Cardiorespiratory depression was not reported, and no serious TEAEs were treatment related. Study retention was high: 83.3% in the chronic benzodiazepine group and 76.9% in the no-benzodiazepine group. Findings were similar in a sub-analysis of patients who were (n = 44) or were not (n = 75) taking clobazam. SIGNIFICANCE: This analysis of patients from a long-term study shows a similar safety profile of diazepam nasal spray in patients with and without concomitant benzodiazepines, and consistent with the established profile for diazepam. Use of a single dose of diazepam nasal spray and high study retention rates suggest the effectiveness of diazepam nasal spray in patients irrespective of chronic daily benzodiazepine use. Results were similar in the clobazam sub-analysis. These results support the safety and effectiveness of diazepam nasal spray in patients with concomitant benzodiazepine use.

Final results from a Phase 3, long-term, open-label, repeat-dose safety study of diazepam nasal spray for seizure clusters in patients with epilepsy.

OBJECTIVE: A Phase 3 open-label safety study (NCT02721069) evaluated long-term safety of diazepam nasal spray (Valtoco) in patients with epilepsy and frequent seizure clusters. METHODS: Patients were 6-65 years old with diagnosed epilepsy and seizure clusters despite stable antiseizure medications. The treatment period was 12 months, with study visits at Day 30 and every 60 days thereafter, after which patients could elect to continue. Doses were based on age and weight. Seizure and treatment information was recorded in diaries. Treatment-emergent adverse events (TEAEs), nasal irritation, and olfactory changes were recorded. RESULTS: Of 163 patients in the safety population, 117 (71.8%) completed the study. Duration of exposure was ≥12 months for 81.6% of patients. There was one death (sudden unexpected death in epilepsy) and one withdrawal owing to a TEAE (major depression), both considered unlikely to be related to treatment. Diazepam nasal spray was administered 4390 times for 3853 seizure clusters, with 485 clusters treated with a second dose within 24 h; 53.4% of patients had monthly average usage of one to two doses, 41.7% two to five doses, and 4.9% more than five doses. No serious TEAEs were considered to be treatment related. TEAEs possibly or probably related to treatment (n = 30) were most commonly nasal discomfort (6.1%); headache (2.5%); and dysgeusia, epistaxis, and somnolence (1.8% each). Only 13 patients (7.9%) showed nasal irritation, and there were no relevant olfactory changes. The safety profile of diazepam nasal spray was generally similar across subgroups based on age, monthly usage, concomitant benzodiazepine therapy, or seasonal allergy/rhinitis. SIGNIFICANCE: In this large open-label safety study, the safety profile of diazepam nasal spray was consistent with the established profile of rectal diazepam, and the high retention rate supports effectiveness in this population. A second dose was used in only 12.6% of seizure clusters.

Video quality using outpatient smartphone videos in epilepsy: Results from the OSmartViE study.

BACKGROUND AND PURPOSE: The aim of this study was to evaluate the quality of smartphone videos (SVs) of neurologic events in adult epilepsy outpatients. The use of home video recording in patients with neurological disease states is increasing. Experts interpretation of outpatient smartphone videos of seizures and neurological events has demonstrated similar diagnostic accuracy to inpatient video-electroencephalography (EEG) monitoring. METHODS: A prospective, multicenter cohort study was conducted to evaluate SV quality in patients with paroxysmal neurologic events from August 15, 2015 through August 31, 2018. Epileptic seizures (ESs), psychogenic nonepileptic attacks (PNEAs), and physiologic nonepileptic events (PhysNEEs) were confirmed by video-EEG monitoring. Experts and senior neurology residents blindly viewed cloud-based SVs without clinical information. Quality ratings with regard to technical and operator-driven metrics were provided in responses to a survey. RESULTS: Forty-four patients (31 women, age 45.1 years [r = 20-82]) were included and 530 SVs were viewed by a mean of seven experts and six residents; one video per patient was reviewed for a mean of 133.8 s (r = 9-543). In all, 30 patients had PNEAs, 11 had ESs, and three had PhysNEEs. Quality was suitable in 70.8% of SVs (375/530 total views), with 36/44 (81.8%) patient SVs rated as adequate by the majority of reviewers. Accuracy improved with the presence of convulsive features from 72.4% to 98.2% in ESs and from 71.1% to 95.7% in PNEAs. An accurate diagnosis was given by all reviewers (100%) in 11/44 SVs (all PNEAs). Audio was rated as good by 86.2% of reviewers for these SVs compared with 75.4% for the remaining SVs (p = 0.01). Lighting was better in SVs associated with high accuracy (p = 0.06), but clarity was not (p = 0.59). Poor video quality yielded unknown diagnoses in 24.2% of the SVs reviewed. Features hindering diagnosis were limited interactivity, restricted field of view and short video duration. CONCLUSIONS: Smartphone video quality is adequate for clinical interpretation in the majority of patients with paroxysmal neurologic events. Quality can be optimized by encouraging interactivity with the patient, adequate duration of the SV, and enlarged field of view during videography. Quality limitations were primarily operational though accuracy remained for SV review of ESs and PNEAs.

The effect of weight reduction surgery on the efficacy and tolerability of epilepsy pharmacotherapy.

BACKGROUND: Bariatric surgery is an increasingly utilized procedure among patients with obesity-related medical complications. The impact of bariatric surgery on seizure frequency and antiseizure drug (ASD) levels are not well described. METHODS: We conducted a retrospective chart review of adult patients with a history of epilepsy or seizures undergoing bariatric surgery for morbid obesity from September 1997-September 2019. The median follow-up was 60 months [range 9-220 months]. RESULTS: Forty-six patients with a history of seizures were identified (38 female); 44 patients had recurrent and unprovoked seizures. Seventeen sets of pre- and post-surgery drug concentrations from 14 patients were reviewed. The median age at surgery was 44 years (range, 19-68). Thirty-three patients were prescribed ASDs at the time of bariatric surgery (median 1 drug [range, 1-3]). Laparoscopic Roux-en-Y was performed in 40 patients, and sleeve gastrectomy in 6 patients. Median pre-surgery weight was 120.75 kg (range, 71-230) and BMI 44.4 kg/m2 (range, 34-77.6). Six months following surgery the median weight was 89.5 kg (range, 58.2-202) and BMI 34.2 kg/m2 (range, 24.5-61.9). Nine patients (19.6%) had a worsening of seizure control on long-term follow-up (median 60, range 9-220 months) following bariatric surgery, including five (10.8%) who suffered seizures within 6 months of bariatric surgery. Five patients developed ASD-associated side effects following bariatric surgery including irritability in two patients (levetiracetam and phenytoin) and one patient each suffering from somnolence (phenytoin), hyperammonemic encephalopathy (sodium valproate), and nausea and vomiting (carbamazepine). Subtherapeutic post-surgery drug concentrations were identified in 5 patients and supratherapeutic concentrations in one patient. In the initial 6 months following surgery, ASD doses were increased in five patients and reduced in five. CONCLUSIONS: The majority of patients with epilepsy who undergo bariatric surgery have no change in seizure frequency. However, a significant minority of patients may experience medication side effects or an increase in seizure tendency due to the impact of bariatric surgery on ASD drug absorption and metabolism leading. Pre- and post-surgical serum concentrations should be measured in patients with seizures or epilepsy receiving ASDs.

Lack of observed tolerance to diazepam nasal spray (Valtoco®) after long-term rescue therapy in patients with epilepsy: Interim results from a phase 3, open-label, repeat-dose safety study.

OBJECTIVE: Tolerance is a known consideration for maintenance use of benzodiazepines and other antiseizure drugs; however, clinical experience suggests that tolerance may not be anticipated with long-term intermittent use of benzodiazepines as rescue therapy. Diazepam nasal spray (Valtoco®) is a proprietary intranasal formulation approved for the acute treatment of intermittent, stereotypic episodes of frequent seizure activity (ie, seizure clusters, acute repetitive seizures) in patients with epilepsy aged ≥6 years. Reported here are exploratory analyses investigating whether there was evidence of development of tolerance in an interim analysis of a long-term, phase 3, open-label safety study of diazepam nasal spray. METHODS: Patients and care partners were trained to administer 5, 10, 15, or 20 mg of diazepam nasal spray (age- and weight-based dosing), with a second dose administered 4-12 hours later if needed. A series of analyses were performed to assess evidence of tolerance using 2 equal, adjacent time periods and data for each patient to compare the proportion of events for which second doses of diazepam nasal spray (as a proxy for effectiveness) were administered in period 1 compared with period 2. RESULTS: A total of 175 patients were enrolled at interim cutoff, and 158 were treated with diazepam nasal spray for 3370 seizure-cluster events. For 73.4% of patients, duration of exposure to diazepam nasal spray was ≥12 months. A total of 191 analyses were conducted; the proportion of analyses in which second doses in period 2 were lower than in period 1 was 72.8%. Only 5 analyses showed nominally statistically significant changes (P < 0.05); this is fewer than expected by chance, and these differences were not directionally consistent. There was no safety signal with continued use. CONCLUSIONS: These analyses found no statistical evidence of tolerance with the use of diazepam nasal spray over time based on use of a second dose in an initial period of the study compared with a subsequent period for each patient. These results are in agreement with prior studies of benzodiazepine rescue therapy.

Tau deposition in young adults with drug-resistant focal epilepsy.

OBJECTIVE: To evaluate the presence of tau deposition and pathologic features of chronic traumatic encephalopathy (CTE) in young adult patients treated with focal cortical resections for drug-resistant epilepsy. METHODS: Sixty consecutive patients who had undergone surgical treatment for drug-resistant focal epilepsy between 18 and 45 years of age were identified (2010-2017). Medical records were reviewed to determine clinical factors, including history of head trauma, age at seizure onset, age at surgical resection, seizure type(s) and frequency, imaging findings, and surgical outcome. All formalin-fixed, paraffin-embedded blocks from the surgical specimens from each subject were sectioned and stained with hematoxylin and eosin and antibodies to tau (Thermo Fisher Scientific Clone AT8), and examined blindly for tau pathology, including lesions characteristic of CTE. RESULTS: The median age at resection was 29.5 years (range = 19-45). A history of head trauma was reported in 19 patients. Although none of the patients had pathological findings characteristic of CTE, 23 patients (38%) demonstrated tau-immunoreactive lesions, including neurites, neurofibrillary pretangles, neurofibrillary tangles, subpial tau, and/or glial tau. In 4 of the 23 patients (7% of the cohort; 17% of those with tau pathology), substantial tau burden was identified. Three of these 4 patients had no significant history of head trauma; 1 patient had multiple sports-related concussions. No specific clinical factors correlated with the presence of tau pathology. SIGNIFICANCE: Tau-immunoreactive lesions were found in 38% of 60 patients who underwent a focal cortical resection for drug-resistant focal epilepsy. Diagnostic features of CTE were not detected in any patient; however, the pathological evaluation for CTE was limited to a surgical specimen. The prominent and excessive tau deposition in 23 patients (38%) is abnormal in this age group and warrants further investigation.

De novo mutations in epileptic encephalopathies.

Epileptic encephalopathies are a devastating group of severe childhood epilepsy disorders for which the cause is often unknown. Here we report a screen for de novo mutations in patients with two classical epileptic encephalopathies: infantile spasms (n = 149) and Lennox-Gastaut syndrome (n = 115). We sequenced the exomes of 264 probands, and their parents, and confirmed 329 de novo mutations. A likelihood analysis showed a significant excess of de novo mutations in the ∼4,000 genes that are the most intolerant to functional genetic variation in the human population (P = 2.9 × 10(-3)). Among these are GABRB3, with de novo mutations in four patients, and ALG13, with the same de novo mutation in two patients; both genes show clear statistical evidence of association with epileptic encephalopathy. Given the relevant site-specific mutation rates, the probabilities of these outcomes occurring by chance are P = 4.1 × 10(-10) and P = 7.8 × 10(-12), respectively. Other genes with de novo mutations in this cohort include CACNA1A, CHD2, FLNA, GABRA1, GRIN1, GRIN2B, HNRNPU, IQSEC2, MTOR and NEDD4L. Finally, we show that the de novo mutations observed are enriched in specific gene sets including genes regulated by the fragile X protein (P < 10(-8)), as has been reported previously for autism spectrum disorders.

Obstructive sleep apnea in refractory epilepsy: A pilot study investigating frequency, clinical features, and association with risk of sudden unexpected death in epilepsy.

OBJECTIVE: We aimed to determine the frequency of probable obstructive sleep apnea (pOSA) in refractory epilepsy monitoring unit inpatients and clinical features associated with pOSA, including risk for sudden unexpected death in epilepsy (SUDEP). METHODS: We prospectively recruited 49 consecutive adult patients admitted to the Mayo Clinic Epilepsy Monitoring Unit with focal, generalized, or unclassified epilepsy syndromes. pOSA was identified using oximetric oxyhemoglobin desaturation index (ODI) and the Sleep Apnea-Sleep Disorders Questionnaire (SA-SDQ) and STOP-BAG screening tools. Revised SUDEP Risk Inventory (rSUDEP-7) scores were calculated, and epilepsy patients with and without pOSA were compared with Wilcoxon signed-rank tests. Correlation and regression analyses were utilized to determine relationships between pOSA and rSUDEP-7 scores. RESULTS: Thirty-five percent of patients had pOSA, with a mean ODI of 11.3 ± 5.1/h (range = 5.1-22.8). Patients with pOSA were older and heavier, and more frequently had a focal epilepsy syndrome and longer epilepsy duration, with higher SA-SDQ and STOP-BAG scores (all P < 0.05). Median rSUDEP-7 score was 3 ± 1.4 (range = 0-6). Higher rSUDEP-7 scores were positively correlated with higher ODI (P = 0.036). rSUDEP-7 score ≥ 5 was associated with pOSA by ODI, SA-SDQ, and STOP-BAG questionnaire criteria (P < 0.05). SIGNIFICANCE: Our pilot study identified a high frequency of pOSA in refractory epilepsy monitoring patients, finding that pOSA patients were older and heavier, with higher screening symptoms for sleep apnea and more frequent focal seizures with a longer epilepsy duration. We also found a possible association between OSA and SUDEP risk. Identification and treatment of OSA in patients with epilepsy could conceivably provide a novel approach toward preventing the risk of SUDEP. Future studies with polysomnography are needed to confirm predictive features for OSA in epilepsy populations, and to determine whether OSA is associated with SUDEP risk.

Predictive models in the diagnosis and treatment of autoimmune epilepsy.

OBJECTIVE: To validate predictive models for neural antibody positivity and immunotherapy response in epilepsy. METHODS: We conducted a retrospective study of epilepsy cases at Mayo Clinic (Rochester-MN; Scottsdale-AZ, and Jacksonville-FL) in whom autoimmune encephalopathy/epilepsy/dementia autoantibody testing profiles were requested (06/30/2014-06/30/2016). An Antibody Prevalence in Epilepsy (APE) score, based on clinical characteristics, was assigned to each patient. Among patients who received immunotherapy, a Response to Immunotherapy in Epilepsy (RITE) score was assigned. Favorable seizure outcome was defined as >50% reduction of seizure frequency at the first follow-up. RESULTS: Serum and cerebrospinal fluid (CSF) from 1,736 patients were sent to the Mayo Clinic Neuroimmunology Laboratory for neural autoantibody evaluation. Three hundred eighty-seven of these patients met the diagnostic criteria for epilepsy. Central nervous system (CNS)-specific antibodies were detected in 44 patients. Certain clinical features such as new-onset epilepsy, autonomic dysfunction, viral prodrome, faciobrachial dystonic seizures/oral dyskinesia, inflammatory CSF profile, and mesial temporal magnetic resonance imaging (MRI) abnormalities had a significant association with positive antibody results. A significantly higher proportion of antibody-positive patients had an APE score ≥4 (97.7% vs. 21.6%, p < 0.01). Sensitivity and specificity of an APE score ≥4 to predict presence of specific neural auto-antibody were 97.7% and 77.9%, respectively. In the subset of patients who received immunotherapy (77), autonomic dysfunction, faciobrachial dystonic seizures/oral dyskinesia, early initiation of immunotherapy, and presence of antibodies targeting plasma membrane proteins (cell-surface antigens) were associated with favorable seizure outcome. Sensitivity and specificity of a RITE score ≥7 to predict favorable seizure outcome were 87.5% and 83.8%, respectively. SIGNIFICANCE: APE and RITE scores can aid diagnosis, treatment, and prognostication of autoimmune epilepsy. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

Drug-resistant focal epilepsy in women of childbearing age: Reproduction and the effect of epilepsy surgery.

OBJECTIVE: Women with epilepsy (WWE) have lower birth rates than expected. The reasons for this are multifactorial and involve a complex interaction between reproductive endocrine and psychosocial factors. The effect of epilepsy surgery on reproduction in women with drug-resistant focal epilepsy has not previously been studied. METHODS: Adult women of childbearing age (18-45years old) with drug-resistant focal epilepsy who had undergone a focal cortical resection between 1997 and 2008 at the Mayo Clinic in Rochester, MN were included in the study. Patients who had a history of hysterectomy or tubal ligation or who were menopausal at the time of surgery were excluded. Data on prior pregnancies and births, epilepsy history, surgical treatment, hormonal dysfunction, and socioeconomic status were obtained using a retrospective chart review. Associations between various clinical and demographic variables with changes in pregnancies and births from pre- to postsurgery were assessed using Chi-square or Fisher's exact test for categorical variables and Wilcoxon rank sum test for continuous variables. All tests were 2-sided, and p-values less than 0.05 were considered statistically significant. All analyses were performed using SAS software version 9.2 (SAS INC, Cary NC). RESULTS: One hundred and thirteen women (average age: 30.5years) were included in the study. Average length of follow-up was 5.7years (SD-3.90). Sixty-four patients (57.5%) were nulliparous at the time of surgery. Sixty-one patients (54%) had never been married. Average number of pregnancies per patient prior to surgery was 0.93, and average number of births prior to surgery was 0.73. After surgery, a total of 17 women had a total of 35 pregnancies and 25 births. The average number of pregnancies and births after surgery was 1.27 and 0.96, respectively. Infertility was reported in one patient postoperatively. Patients who were younger at the time of surgery experienced a greater change in the number of pregnancies and births after surgery (p=0.0036 and 0.0060, respectively). Patients who received fewer antiepileptic drug medication trials by the time of surgery also had a greater change in the number of births after surgery (p=0.0362). Seizure onset localization and lateralization, presurgical seizure frequency, age at seizure onset, duration of epilepsy, and postoperative seizure outcome were not statistically significant factors. CONCLUSION: The present retrospective observational study provides additional evidence for the importance of early surgical treatment in women with drug-resistant focal epilepsy. Patients who had received fewer medications prior to surgery were more likely to experience an increase in births following surgery. The significance of these findings requires further investigation but may support a role for earlier surgical intervention in the management of drug-resistant focal epilepsy.