Frontal Seizures Research Articles

Functional seizures and their mimics: a retrospective service review of cases from a tertiary video telemetry database

ObjectiveIdentify the proportion of patients referred with putative functional seizures (FS) that were subsequently re-diagnosed as epileptic seizures (ES), or an alternative diagnosis, following video telemetry EEG (VTEEG). In addition,...

Nocturnal frontal opercular seizures masquerading as catathrenia: a case report and review of the literature

Nocturnal frontal opercular seizures masquerading as catathrenia: a case report and review of the literature

41 Characterizing the Cognitive Profile of Pediatric Insular Epilepsy

Objective:Little research exists characterizing the neuropsychological profile of pediatric insular epilepsy. Accurate diagnosis of insular epilepsy is challenging due to difficulties localizing deep brain structures with current non-invasive neurodiagnostic tools, as well as seizure semiology that may mimic temporal, frontal, and parietal seizures for this patient population [1]. Therefore, we investigated trends across neuropsychological data to help characterize the cognitive profile of pediatric insular epilepsy. This is important because studies that could accurately characterize insular epilepsy into cognitive phenotypes could potentially provide supporting evidence for insular localization during epilepsy surgery work-up. The insula is situated underneath the temporal, parietal, and frontal opercula, and has a number of diffuse projections to key brain structures involved in language, executive functioning, motor coordination, and sensory function [2]. Therefore, we hypothesized that children with insular epilepsy will demonstrate particular weaknesses in language and executive functioning skills.Participants and Methods:Retrospective medical records review identified 19 children with insular epilepsy who completed neuropsychological assessment (Age: M=8.2 years, SD=3.4) at Boston Children’s Hospital. Insular epilepsy was defined by ictal insular localization on long-term monitoring EEG. The current sample includes 59% males and 41% females. The majority of participants (69%) had left sided lateralization and more than one seizure type (63%). MRI findings were widely distributed across frontal, temporal, and multiple lobes as well as insular and perisylvian brain regions. A lesion was identified on MRI findings for most participants (63%).Results:Descriptive analyses showed that overall IQ (FSIQ: M=84, SD=12, range=68-102) fell in the Low Average range. Verbal and visual reasoning skills were equally developed in the Low Average range (VIQ: M=88, SD=12, range=70-104; PIQ: M=88, SD=16, range=53-117). Participants exhibited lower performance on speeded expressive language measures, including measures of phonemic fluency (M=5.5, SD=1.5, range=2-8) and semantic fluency (M=6.7, SD=2.5, range=3-11). With regard to executive functioning, reduced cognitive flexibility was observed on D-KEFS Trail Making Test (Trial 4, Number-Letter Switching: M=5.9, SD=4.9, range=1-12). Additionally, working memory skills fell in the Below Average range (WMIQ: M=77, SD=8.5, range=67-88).Conclusions:Our results indicate that pediatric patients with insular epilepsy present with reduced scores across aspects of speeded expressive language and executive functioning, including working memory and cognitive flexibility. Additional research is needed to replicate these preliminary findings with a larger sample size and determine whether these trends in cognitive profile would help with seizure localization. Future research should investigate whether insular epilepsy has a clearly identifiable and distinct cognitive phenotype that could be helpful in differential diagnostic workup.

Pregnancy Seizure Outcomes for Epilepsy Patients with Catamenial Seizure Exacerbation (P8-1.011)

<h3>Objective:</h3> To assess the risk of increased seizure frequency during pregnancy/early postpartum for patients with a catamenial seizure exacerbation pattern (CSEP) <h3>Background:</h3> Prior studies demonstrated that seizure frequency is mostly stable during pregnancy/early postpartum when therapeutic drug monitoring is performed. Yet, clinical factors - seizure frequency in the 9 months preconception, epilepsy type, ASM regimen and, in one prior study, CSEP - may influence seizure outcomes. <h3>Design/Methods:</h3> Clinical data was collected in a longitudinal prospective database of pregnant women with epilepsy at Brigham and Women’s Hospital. Within each participant, baseline seizure frequency was calculated for the 9 months preconception, and it was determined if seizure frequency increased during pregnancy or the postpartum period. CSEP was determined retrospectively by chart review. Associations between categorical variables were evaluated using the Fisher-Exact test. <h3>Results:</h3> Ninety-nine patients contributing 114 pregnancies were included from 2013–2018. 24 patients contributing 24 pregnancies were determined to have a CSEP (probable n=17 and possible n=7), 29.2% with generalized and 70.8% with focal epilepsy. Only 50% of CSEP group had been seizure free in the 9 months preconception versus 71.7% in the entire cohort; yet, only 16.7% were on polytherapy. The rate of seizure worsening was not significantly different for CSEP group versus the entire cohort during pregnancy (20.8% vs 15.8%) and postpartum (5.3% vs 9.8%). As previously reported, frontal lobe epilepsy was a risk factor: 50.0% of CSEP patients with frontal lobe epilepsy experienced seizure worsening in pregnancy vs 52.9% of all frontal lobe epilepsy patients. <h3>Conclusions:</h3> CSEP patients have a similar risk of seizure worsening in pregnancy/early postpartum to all patients with epilepsy, despite the worse preconception seizure baseline and a lower rate of polytherapy than expected. CSEP does not mediate the high risk of seizure worsening during pregnancy for frontal lobe epilepsy. <b>Disclosure:</b> The institution of Dr. Voinescu has received research support from NIH. Dr. Voinescu has received personal compensation in the range of $500-$4,999 for serving as a Speaker with Neurodiem. Dr. Voinescu has received personal compensation in the range of $500-$4,999 for serving as a Speaker with Physicians’ Education Resouce. Dr. Voinescu has received personal compensation in the range of $500-$4,999 for serving as a Speaker with American Epilepsy Society. Dr. Voinescu has a non-compensated relationship as a Board Member and Chair with My Epilepsy Story that is relevant to AAN interests or activities. Dr. Voinescu has a non-compensated relationship as a Speaker with Epilepsy Foundation that is relevant to AAN interests or activities. Dr. Voinescu has a non-compensated relationship as a Grant Reviewer with Epilepsy Ireland that is relevant to AAN interests or activities. Dr. Voinescu has a non-compensated relationship as a Grant Reviewer with American Epilepsy Society that is relevant to AAN interests or activities. Dr. Voinescu has a non-compensated relationship as a Member of Scientific Advisory Committee with North American AED Pregnancy Registry that is relevant to AAN interests or activities. Dr. Lemus Esquivel has nothing to disclose. Dr. Liu has nothing to disclose. Mrs. Allien has nothing to disclose. Dr. Pennell has received personal compensation in the range of $0-$499 for serving as an officer or member of the Board of Directors for American Epilepsy Society. The institution of Dr. Pennell has received research support from NIH. The institution of an immediate family member of Dr. Pennell has received research support from Department of Defense. The institution of an immediate family member of Dr. Pennell has received research support from Environmental Protection Agency. The institution of an immediate family member of Dr. Pennell has received research support from NIH. The institution of an immediate family member of Dr. Pennell has received research support from Advanced Energy Consortium. Dr. Pennell has received publishing royalties from a publication relating to health care.

449 Stereoencephalography of Centromedian Thalamus Reveals Distinct Patterns of Thalamocortical Synchrony Across Seizure Onset Zones

INTRODUCTION: Thalamic nuclei are increasingly used targets for study and therapeutic modulation in drug-resistant epilepsy (DRE). Centromedian nucleus of thalamus (CMN) is relatively understudied despite known widespread connectivity and previous reports suggesting a role in both generalized and multifocal epilepsies. METHODS: The clinical and electrographic data of 13 consecutive patients who had at least one sEEG electrode sampling CMN were included. Electrographic seizures were visually analyzed for thalamic activity changes at seizure onset (SO), maintenance (SM), and end (SE) periods. Recordings were quantitatively assessed using a measure of sEEG signal interdependency (non-linear regression coefficient, h2) to compare thalamocortical synchrony at SO and SE periods. All analyses were performed using AnyWave software. RESULTS: Eighty focal-onset seizures (median 4, range 1-19 per patient) were captured and included in analysis. SOZs were mesial temporal (33%), neocortical temporal (23%), frontal (29%), and non-frontal extratemporal (15%). Median seizure length was 78 (IQR 25-133) seconds. In 74% of seizures, a change in thalamic activity was visually perceptible during the seizure with a median latency of 5 (IQR 2-9) seconds. A low voltage fast activity pattern predominantly in the alpha band was most commonly seen during SO. When thalamic activity changed during SM, a rhythmic spike-wave pattern was most often seen. Rhythmic waves predominantly in the delta band were the most common pattern of activity at SE. Average thalamocortical h2 values in the SE period were significantly higher than the SO period (Kruskal-Wallis p &lt; 0.0001). Mesial temporal, temporal, and frontal seizures demonstrated significant increases in thalamocortical synchronization while non-frontal extratemporal seizures did not. CONCLUSIONS: Consistent dynamic ictal patterns can be visualized within CMN thalamus using sEEG recordings. Bidirectional signal synchronization peaks during the SE period and may be involved in seizure termination.

Post-ictal Rhythmic Thalamic Activity of the Centromedian Nucleus.

Deep brain stimulation of the centromedian nucleus of the thalamus (CMN) to treat drug-resistant epilepsy has been of interest for decades. However, little is known about the electrophysiological activity of the CMN during seizures. We describe a novel CMN EEG finding associated with seizure: post-ictal rhythmic thalamic activity. Five patients with drug-resistant epilepsy of unknown etiology with focal onset seizures underwent stereoelectroencephalography monitoring as part of evaluation for potential resective surgery or neuromodulation. Two patients had previously undergone complete corpus callosotomy and vagus nerve stimulation. A standardized plan for implantation included targets in the bilateral CMN. Each patient had frontal onset seizures, and two patients had additional insular, parietal, or mesial temporal onset seizures. Contacts of CMN were involved synchronously or rapidly after onset in most recorded seizures, particularly those with frontal onset. Focal onset hemiclonic and bilateral tonic-clonic seizures spread to involve cortical contacts with high-amplitude rhythmic spiking followed by abrupt offset with diffuse voltage attenuation. A post-ictal rhythmic 1.5 to 2.5 Hz delta frequency pattern, post-ictal rhythmic thalamic activity, emerged in CMN contacts amid the suppression of background activity in cortical contacts. In the two patients with corpus callosotomy, unilateral seizure spread and ipsilateral post-ictal rhythmic thalamic activity were observed. We observed post-ictal rhythmic thalamic activity in five patients with stereoelectroencephalography monitoring of the CMN with convulsive seizures. This rhythm appears late in ictal evolution and may signal an important role of the CMN in seizure termination. Furthermore, this rhythm may help identify CMN involvement in the epileptic network.

Teaching NeuroImage: Ictal Pouting Associated With Focal Cortical Dysplasia and Frontal Seizures on Stereotactic Depth Electrode EEG.

Teaching NeuroImage: Ictal Pouting Associated With Focal Cortical Dysplasia and Frontal Seizures on Stereotactic Depth Electrode EEG.

Auditory verbal hallucination can be evoked by prefrontal epileptic seizure

Auditory verbal hallucinations (AVHs) have been reported in neocortical temporal epileptic seizures and have been considered highly associated with implication of auditory cortex by epileptic discharges or electrical stimulation. Herein, we report two rare frontal epilepsy cases in which AVHs featured the habitual seizures. The epileptogenic zones of these two patients were localized in the dorsal and orbitomedial prefrontal cortex, respectively by stereoelectroencephalography (SEEG) monitoring. Comparing with the AVHs in schizophrenia, we postulated that the phenomenological similarities between the two sets of AVHs imply homology in mechanisms. Ictal SEEG confirmed that the wide involvement of prefrontal–cingulate–auditory cortical network by low-voltage fast activity corresponded the occurrence with AVHs during frontal epileptic seizures. Electrical stimulation study of one of the two cases highlighted the causal role of prefrontal–cingulate cortex in the emergence of AVHs. Based on our clinical observation, SEEG findings, and electrical cortical stimulation, we supposed that wide implication of prefrontal–cingulate–auditory cortical network during epileptic seizure underlie the emergence of AVHs, and further hypothesized that AVHs could be yielded by transient deficit of self-monitoring for inner speech in focal epileptic seizures.

The β2V287L nicotinic subunit linked to sleep-related epilepsy differently affects fast-spiking and regular spiking somatostatin-expressing neurons in murine prefrontal cortex.

Mutant subunits of the neuronal nicotinic ACh receptor (nAChR) can cause Autosomal Dominant Sleep-related Hypermotor Epilepsy (ADSHE), characterized by frontal seizures during non-rapid eye movement (NREM) sleep. We studied the cellular bases of the pathogenesis in brain slices from mice conditionally expressing the ADSHE-linked β2V287L nAChR subunit. β2V287L mice displayed minor structural alterations, except for a ~10% decrease of prefrontal cortex thickness. However, they showed a substantial decrease of the excitatory input to layer V fast-spiking (FS) interneurons, despite a concomitant increase in the number of glutamatergic terminals around the cell soma. Hence, prefrontal hyperexcitability may depend on a permanent impairment of surround inhibition. The effect disappeared when β2V287L was silenced until postnatal day 15th, suggesting that the transgene selectively affects the maturation of glutamatergic synapses on FS neurons. The other main population of interneurons in layer V was constituted by somatostatin-expressing regular spiking cells. When tested with 10µM nicotine, these displayed larger somatic nicotinic currents in transgenic mice. Thus, during wakefulness, activation of β2V287L-containing nAChRs by the high cholinergic tone may counteract hyperexcitability by promoting local inhibition by somatostatin-expressing cells and decreasing the effect of glutamatergic deficit in FS neurons. This interpretation was tested in networks disinhibited by 2μM bicuculline. Slices expressing β2V287L were more susceptible to develop synchronized activity in the absence of nicotine. Addition of the drug boosted excitability in the controls, but had little effect in β2V287L. Our findings suggest why NREM sleep favors ADSHE seizures and nicotine can be palliative in patients.

Sequential Semiology of Seizures and Brain Perfusion Patterns in Patients with Drug-Resistant Focal Epilepsies: A Perspective from Neural Networks.

Ictal semiology and brain single-photon emission computed tomography have been performed in approaching the epileptogenic zone in drug-resistant focal epilepsies. The authors aim to describe the brain structures involved in the ictal and interictal epileptogenic network from sequential semiology and brain perfusion quantitative patterns analysis. A sequential representation of seizures was performed (n = 15). A two-level analysis (individual and global) was carried out for the analysis of brain perfusion quantification and estimating network structures from the perfusion indexes. Most of the subjects started with focal seizures without impaired consciousness, followed by staring, automatisms, language impairments and evolution to a bilateral tonic-clonic seizure (temporal lobe and posterior quadrant epilepsy). Frontal lobe epilepsy seizures continued with upper limb clonus and evolution to bilateral tonic-clonic. The perfusion index of the epileptogenic zone ranged between 0.439–1.362 (mesial and lateral structures), 0.826–1.266 in dorsolateral frontal structures and 0.678–1.507 in the occipital gyrus. The interictal epileptogenic network proposed involved the brainstem and other subcortical structures. For the ictal state, it included the rectus gyrus, putamen and cuneus. The proposed methodology provides information about the brain structures in the neural networks in patients with drug-resistant focal epilepsies.

Frontal lobe seizures: overview and update.

Frontal lobe seizures (FLS) are debilitating for patients, highly diverse and often challenging for clinicians to evaluate. Frontal lobe epilepsy is the second most common localization for focal epilepsy, and if pharmacoresistant, can be amenable to resective surgery. Detailed study of frontal seizure semiology in conjunction with careful anatomical and electrophysiological correlation based on intracerebral recording with stereoelectroencephalography (SEEG) has allowed demonstration that ictal motor semiology reflects a hierarchical rostro-caudal axis of frontal lobe functional organization, thus helping with presurgical localization. Main semiological features allowing distinction between different frontal sublobar regions include motor signs and emotional signs. Frontal lobe seizure semiology also represents a valuable source of in vivo human behavioral data from a neuroscientific perspective. Advances in defining underlying etiologies of FLE are likely to be crucial for appropriate selection and exploration of potential surgical candidates, which could improve upon current surgical outcomes. Future research on investigating the genetic basis of epilepsies and relation to structural substrate (e.g. focal cortical dysplasia) and seizure organization and expression, could permit a "genotype-phenotype" approach that could be complementary to anatomical electroclinical correlations in better defining the spectrum of FLS. This could help with optimizing patient selection and prognostication with regards to therapeutic choices.

A comparative study of AI systems for epileptic seizure recognition based on EEG or ECG.

The majority of studies for automatic epileptic seizure (ictal) detection are based on electroencephalogram (EEG) data, but electrocardiogram (ECG) presents a simpler and more wearable alternative for long-term ambulatory monitoring. To assess the performance of EEG and ECG signals, AI systems offer a promising way forward for developing high performing models in securing both a reasonable sensitivity and specificity. There are crucial needs for these AI systems to be developed with more clinical relevance and inference generalization. In this work, we implement an ECG-specific convolutional neural network (CNN) model with residual layers and an EEG-specific convolutional long short-term memory (ConvLSTM) model. We trained, validated, and tested these models on a publicly accessible Temple University Hospital (TUH) dataset for reproducibility and performed a non-patient-specific inference-only test on patient EEG and ECG data of The Royal Prince Alfred Hospital (RPAH) in Sydney, Australia. We selected 31 adult patients to balance groups with the following seizure types: generalized, frontal, frontotemporal, temporal, parietal, and unspecific focal epilepsy. Our tests on both EEG and ECG of these patients achieve an AUC score of 0.75. Our results show ECG outperforms EEG with an average improvement of 0.21 and 0.11 AUC score in patients with frontal and parietal focal seizures, respectively.Clinical relevance-Prior research has demonstrated the value of using ECG for seizure documentation. It is believed that specific epileptic foci (seizure origin) may involve network inputs to the autonomic nervous system. Our result indicates that ECG could outperform EEG for individuals with specific seizure origin, particularly in the frontal and parietal lobes.

Experience and consensus on stimulation of the anterior nucleus of thalamus for epilepsy.

Deep brain stimulation of the anterior nuclei of thalamus (ANT-DBS) is effective for reduction of seizures, but little evidence is available to guide practitioners in the practical use of this therapy. In an attempt to fill this gap, a questionnaire with 37 questions was circulated to 578clinicians who were either engaged in clinical trials of or known users of DBS for epilepsy, with responses from 141, of whom 58.2% were epileptologists and 28.4% neurosurgeons. Multiple regions of the world were represented. The survey found that the best candidates for DBS were considered those with temporal or frontal seizures, refractory to at least two medicines. Motivations for renewing therapy upon battery depletion were reduced convulsive, impaired awareness, and severe seizures and improved quality of life. Targeting of leads mainly was by magnetic resonance imaging, sometimes with intraoperative imaging or microelectrode recording. The majority used transventricular approaches. Stimulation parameters mostly imitated the SANTE study parameters, except for initial stimulation amplitudes in the 2-3-V or -mA range, versus 5V in the SANTE study. Stimulation intensity was most often increased or reduced, respectively, for lack of efficacy or side effects, but changes in active contacts, cycle time, and pulse duration were also employed. Mood or memory problems or paresthesias were the side effects most responsible for adjustments. Off-label sites stimulated included centromedian thalamus, hippocampus, neocortex, and a few others. Several physicians used DBS in conjunction with vagus nerve stimulation or responsive neurostimulation, although our study did not track efficacy for combined use. Experienced users varied more from published parameters than did inexperienced users. In conclusion, surveys of experts can provide Class IV evidence for the most prevalent practical use of ANT-DBS. We present a flowchart for one protocol combining common practices. Controlled comparisons will be needed to choose the best approach.

WITHDRAWN

TOPIC: Sleep Disorders TYPE: Fellow Case Reports INTRODUCTION: Vagal nerve stimulation (VNS), which was approved by the FDA in 1997, has been used to treat refractory partial and complex seizures in patients with epilepsy. In this case report, we describe an important adverse effect of vagal nerve efferent stimulation to upper airway structures. Multiple studies have shown that VNS can induce or worsen obstructive sleep apnea (OSA). For treating patients with VNS-induced OSA, manufacturers suggest decreasing VNS frequency and increasing the cycle off time. However, this recommendation rarely provides successful results. Here, we illustrate a case of a woman with VNS-induced OSA and show how small adjustments to VNS current and pulse width parameters can significantly reduce the effects of VNS-induced obstructive respiratory events during a PAP titration without breakthrough seizures. CASE PRESENTATION: The patient is a 52-year-old woman who had a vagal nerve stimulator placed in 1998 for refractory left frontal lobe focal seizures. She presented to the sleep medicine clinic for excessive daytime sleepiness, non-refreshing sleep, and reports of loud snoring. Her symptoms were present despite adequate sleep hygiene and a consistent 8.5 hours of sleep each night. A split night study revealed an apnea-hypopnea index (AHI) of 32.8 with predominant obstructive hypopneas and occasional obstructive apneas. Her obstructive respiratory events occurred coincidentally in sequence with 30 seconds of electromyography (EMG) chin tone every 108 seconds. Subsequent, bilevel positive airway pressure (BPAP) titration was unsuccessful. The patient's neurologist was notified of the sleep study findings and the patient's VNS was adjusted. The output current, pulse width, magnet current, and a magnet pulse bandwidth were reduced. All other parameters remained unchanged including frequency and cycle time. On her subsequent BPAP titration, her OSA was successfully controlled at a BPAP pressure of 23/19 cm H2O, with a residual AHI of 0. On follow-up, the patient was adherent to her BPAP therapy with subjective improvement in quality of her sleep. The patient did not have breakthrough seizures over one year with the decrease in current and pulse width settings on her VNS. She averaged 5.5 hours of BPAP use each night with 73% of days used over one year. DISCUSSION: In this case report, we have outlined a successful BPAP titration with minor adjustments in VNS parameters in a patient with epilepsy and severe OSA. The success of this BPAP titration was likely facilitated by the reduction in VNS output current and pulse bandwidth, which reduced the efferent motor nerve stimulation of upper airway structures. CONCLUSIONS: This case demonstrates how adjustment of specific VNS parameters may potentially provide an alternative to the recommended adjustment in frequency and cycle times; however, this strategy will ultimately need to be tested and closely monitored in more patients. REFERENCE #1: Howland RH. Vagus Nerve Stimulation. Curr Behav Neurosci Rep. 2014;1(2):64-73. REFERENCE #2: Parhizgar F, Nugent K, Raj R. Obstructive sleep apnea and respiratory complications associated with vagus nerve stimulators. J Clin Sleep Med. 2011 Aug 15;7(4):401-7. REFERENCE #3: Ebben MR; Sethi NK; Conte M; Pollak CP; Labar D. Vagus nerve stimulation, sleep apnea, and CPAP titration. J Clin Sleep Med. 2008;4(5):471–473. DISCLOSURES: No relevant relationships by Jovica Veljanovski, source=Web Response No relevant relationships by Joshua Won, source=Web Response

Anticonvulsant dopamine type 2 receptor agonist activates inhibitory parvalbumin interneurons.

Dopamine type 2 receptor (D2R) agonists have anticonvulsant effect, whereas D2R antagonists increase seizure risk, but the mechanism of this action has not been delineated. We tested whether D2R agonists activate parvalbumin (PV)-containing inhibitory interneurons to suppress seizures. We treated frontal lobe onset seizures with a D2R agonist sumanirole, and it suppressed seizures. We used activity reporter TRAP2mice and found that injection of D2R agonist led to extensive activation of PV interneurons in the cortex and striatum ipsilateral to the seizure focus. D2R agonists activate PV interneurons, which in turn inhibit principal neurons, potentially explaining their anticonvulsant effect.

P3. Significance of intracranial EEG parameters in prediction of seizure freedom

Introduction. In patients with focal drug-resistant epilepsy (DRE), intracranial electroencephalography (iEEG) with subdural electrodes (SDE) is used to delineate the seizure onset zone (SOZ) and to distinguish eloquent cortex areals, if non-invasive diagnostics did not yield conclusive results. Previous studies have shown ambiguous findings on the significance of iEEG parameters with respect to prediction of seizure freedom after resective epilepsy surgery. Most studies focused on subgroups of patients, such as those with frontal or temporal lobe epilepsy, or on some iEEG parameters, only. To that end, we comprehensively analyzed the significance of several iEEG parameters in one set of consecutive patients with DRE. Methods. All patients who had undergone invasive monitoring with SDE between 2005 and 2015 at our tertiary epilepsy center were included in this study 1 . We retrospectively analyzed iEEG parameters including seizure onset pattern (SOP), size of SOZ, latency to EEG seizure propagation and latency from clinical to EEG seizure onset. Furthermore, we assessed associations with post-operative seizure freedom, histopathology und brain region of SOZ. Results. Eighty-one patients (34 female) with 324 seizures were assessed. Low-voltage fast activity (LVFA, 37%) and sharp activity < 13 Hz (30%) were the most frequent SOPs. Focal SOZ (≤2 cm) was the only iEEG parameter independently associated with 1-year post-operative seizure freedom (OR 4.1, 95% CI 1.433–11.679). While no SOP was linked to specific histopathologies, LVFA was associated with temporal neocortical SOZ ( p < 0.01). Median latencies to EEG seizure propagation were significantly longer ( p < 0.001) in seizures originating from temporo-mesial SOZ (median 16.0 s) compared with temporo-neocortical (median 8.0 s) and frontal seizure onset (median 5.5 s). Also, latencies from clinical to EEG seizure onset were significantly longer ( p < 0.001) in seizures from temporo-mesial SOZ (median −20.0 s) compared with temporo-neocortical (median −12.0 s) and frontal seizure onset (median −6.0 s). Discussion. A focal EEG seizure onset but no specific SOP predicted seizure freedom after surgery. Also, different SOPs could be generated by the same histopathology and vice versa, putting clinical significance of SOPs into question. LVFA was associated with temporal neocortical seizure onset, possibly indicating a close-by seizure generator. Longer latencies until seizure spread and clinical signs or symptoms in seizures originating from temporo-mesial SOZ may be explained by inhibitory circuits in the hippocampus. Reference 1. Steinbart D, Steinbrenner M, Oltmanns F, Holtkamp M. Prediction of seizure freedom after epilepsy surgery – critical reappraisal of significance of intracranial EEG parameters. Clin Neurophysiol. 2020;131(11):2682-2690. doi:https://doi.org/10.1016/j.clinph.2020.08.018

Activation of the basal ganglia and indirect pathway neurons during frontal lobe seizures

There are no detailed descriptions of neuronal circuit active during frontal lobe motor seizures. Using activity reporter mice, local field potential recordings, tissue clearing, viral tracing, and super-resolution microscopy, we found neuronal activation after focal motor to bilateral tonic-clonic seizures in the striatum, globus pallidus externus, subthalamic nucleus, substantia nigra pars reticulata and neurons of the indirect pathway. Seizures preferentially activated dopamine D2 receptor-expressing neurons over D1 in the striatum, which have different projections. Furthermore, the D2 receptor agonist infused into the striatum exerted an anticonvulsant effect. Seizures activate structures via short and long latency loops, and anatomical connections of the seizure focus determine the seizure circuit. These studies, for the first time, show activation of neurons in the striatum, globus pallidus, subthalamic nucleus, and substantia nigra during frontal lobe motor seizures on the cellular level, revealing a complex neuronal activation circuit subject to modulation by the basal ganglia.

Different faces of frontal lobe epilepsy: The clinical, electrophysiologic, and imaging experience of a tertiary center

ObjectiveFrontal lobe epilepsy (FLE) is the second most common epilepsy among drug-resistant focal epilepsies. Semiologic and electrophysiologic features of FLE present some difficulties because frontal lobe seizures are brief, accompanied by complex motor activities and emotional signs. The rich connectivity of the frontal lobe with other areas leads to the rapid and widespread propagation of seizure activity, which contribute to the difficulty of evaluating the semiologic and EEG patterns of the seizure. In this study, we investigated semiologic, interictal, ictal, and postictal EEG characteristics; the imaging data of patients with FLE and the possible contribution of these data to localization and lateralization of seizures. Materials and methodsThe medical records of patients who were diagnosed as having FLE between 2010 and 2019 in our clinic were evaluated retrospectively. The diagnosis of FLE was considered either when patients had a structural lesion in the frontal region or seizure semiology and EEG characteristics were compatible with FLE. Clinical, electrophysiologic, and imaging features were investigated in these patients. ResultsWe have evaluated 146 seizures in 36 patients (17 lesional and 19 non-lesional according to MRI). There were 110 focal motor or nonmotor seizures, 18 bilateral tonic-clonic seizures, and 18 subclinical seizures. There were 16 patients with aura. The most common semiologic feature was hyperkinetic movements. Among the interictal EEGs, 30.5 % included focal anomalies. Among the ictal EEGs, 69.1 % were non-localizing or lateralizing. The most common ictal pattern was rhythmic theta activity (21.2 %). In four patients, who had non-localizing or lateralizing EEG, the postictal EEG was informative. Our study showed a low percentage of localized FDG-PET, which, however, involved visual analysis. ConclusionOur results support the previously known difficulties in the determination of the epileptogenic zone of FLE. Semiologic and electrophysiologic correlation studies, longer postictal records, and quantitative analysis of FDG-PET may contribute to a better characterization of the disease.

Post-Acute Sequelae of SARS-Cov-2 Infection Associating Peripheral, Autonomic and Central Nervous System Disturbances: Case Report and Review of the Literature

Aim: To describe post-infectious neurological aspects of COVID-19 in a patient with progressive post-infectious peripheral (PNS), autonomic (ANS) and central nervous system (CNS) involvement due to SARS-CoV-2 infection. Background and Purpose: A variety of neurological manifestations have been described in association with Covid-19, however, progressive multisystem neurological aspects have not been described. Methods: A case report detailing the history, examination, and infectious serology associated with SARS-CoV-2, and subsequent neurodiagnostic laboratory testing and treatment. Results: Neurodiagnostic laboratory studies showed large-fiber demyelinating sensorimotor and painful small fiber sensory polyneuropathy, orthostatic hypotension, and hypometabolism of bilateral anterior and mesial temporal lobes with a possible frontal seizure focus. Treatment was initiated with high-dose immune globulin therapy. Conclusions: The combination of PNS, ANS and CNS involvement in this patient was associated with post-infectious acquired immunity to SARS-CoV-2.

Clinical and electrographic features of persistent seizures and status epilepticus associated with anti-NMDA receptor encephalitis (anti-NMDARE).

Based on a multicenter cohort of people with anti-NMDA receptor encephalitis (anti-NMDARE), we describe seizure phenotypes, electroencephalographic (EEG) findings, and anti-seizure treatment strategies. We also investigated whether specific electrographic features are associated with persistent seizures or status epilepticus after acute presentation. In this retrospective cohort study, we reviewed records of children and adults with anti-NMDARE between 2010 and 2014 who were included in the Rare Epilepsy of New York City database, which included the text of physician notes from five academic medical centers. Clinical history (e.g., seizure semiology) and EEG features (e.g., background organization, slowing, epileptiform activity, seizures, sleep architecture, extreme delta brush) were abstracted. We compared clinical features associated with persistent seizures (ongoing seizures after one month from presentation) and status epilepticus, using bivariate and multivariable analyses. Among the 38 individuals with definite anti-NMDARE, 32 (84%) had seizures and 29 (76%) had seizures captured on EEG. Electrographic-only seizures were identified in five (13%) individuals. Seizures started at a median of four days after initial symptoms (IQR: 3-6 days). Frontal lobe-onset focal seizures were most common (n=12; 32%). Most individuals (31/38; 82%) were refractory to anti-seizure medications. Status epilepticus was associated with younger age (15 years [9-20] vs. 23 years [18-27]; p=0.04) and Hispanic ethnicity (30 [80%] vs. 8 [36%]; p=0.04). Persistent seizures (ongoing seizures after one month from presentation) were associated with younger age (nine years [3-14] vs. 22 years [15-28]; p<0.01). Measured electrographic features were not associated with persistent seizures. Seizures associated with anti-NMDARE are primarily focal seizures originating in the frontal lobes. Younger patients may be at increased risk of epileptogenesis and status epilepticus. Continuous EEG monitoring helps identify subclinical seizures, but specific EEG findings may not predict the severity or persistence of seizures during hospitalization.