Focal Discharges Research Articles

The Agreement Between Long-Term Monitoring by Electroencephalography and Magnetic Resonance Imaging in Paediatric Seizure

Background: Demonstration of high agreement between structural abnormalities identified on magnetic resonance imaging (MRI) and physiologic abnormalities identified on electroencephalography (EEG) could benefit the assessment of epileptic focus in childhood seizures. Objectives: The present study aimed to assess the agreement between abnormal findings on brain MRI and long-term monitoring (LTM) by EEG as the standard protocol in children with abnormal focal epileptic discharges in LTM. Methods: This cross-sectional study was performed on 95 children who suffered from seizures with evidence of focal epileptic discharges in LTM who were referred to the Children's Medical Center in 2017. All patients were also concurrently evaluated by MRI. All MRIs were evaluated twice, before and after receiving the EEG results. Results: In this study, 59 out of 95 patients with abnormal LTM had concurrently abnormal MRI findings. The diagnostic agreement between the MRI and LTM in discovering abnormal findings was found to be high (86.4%) with a kappa correlation coefficient equal to 0.79. Conclusions: About two-thirds of patients with abnormal LTM findings had concurrent abnormal MRI features with high agreement between the two. Thus, MRI and EEG can be valuable in predicting epileptic focus in drug-resistant patients who need surgery.

Enhanced sensitivity of electrocorticography during awake craniotomy using a novel circular grid electrode.

Awake craniotomy with intraoperative functional brain mapping (FBM) bedside neurological testing is an important technique used to optimize resective brain surgeries near eloquent cortex. Awake craniotomy performed with electrocorticography (ECoG) and direct electrical stimulation (DES) for FBM can delineate eloquent cortex from lesions and epileptogenic regions. However, current electrode technology demonstrates spatial limitations. Our group has developed a novel circular grid with the goal of improving spatial recording of ECoG to enhance detection of ictal and interictal activity. This retrospective study was approved by the institutional review board at Mayo Clinic Florida. We analyzed patients undergoing awake craniotomy with ECoG and DES and compared ECoG data obtained using the 22 contact circular grid to standard 6 contact strip electrode. We included 144 cases of awake craniotomy with ECoG, 73 using circular grid and 71 with strip electrode. No significant differences were seen regarding preoperative clinical and demographic data, duration of ECoG recording (p = 0.676) and use of DES (p = 0.926). Circular grid was more sensitive in detecting periodic focal epileptiform discharges (PFEDs) (p = 0.004), PFEDs plus (p = 0.032), afterdischarges (ADs) per case (p = 0.022) at lower minimum (p = 0.012) and maximum (p < 0.0012) intensity stimulation, and seizures (p = 0.048). PFEDs (p < 0.001), PFEDs plus (p < 0.001), and HFOs (p < 0.001) but not ADs (p = 0.255) predicted electrographic seizures. We demonstrate higher sensitivity in detecting ictal and interictal activity on ECoG during awake craniotomy with a novel circular grid compared to strip electrode, likely due to better spatial sampling during ECoG. We also found association between PFEDs and intraoperative seizures.

Tuberozinės sklerozės kompleksas ir epilepsija. Literatūros apžvalga

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterized by the presence of benign tumors in many organs. The pathogenic mutation is found in either the TSC1 or TSC2 tumor suppressor genes. The presence of cortical or subcortical tubers is associated with focal epileptiform discharges on the electroencephalogram and subclinical seizures prior to the onset of clinical seizures. It is known that epileptic seizures in tuberous sclerosis are very resistant to the treatment, therefore, developmental delay usually occurs. In the last decade, more attention has been paid to early recognition and control of seizures (with vigabatrin or everolimus) in tuberous sclerosis complex, as this is highly correlated with improved developmental and neurological outcomes.The article reviews epilepsy and preventive antiepileptic treatment for tuberous sclerosis complex.

The differing effects of sleep on ictal and interictal network dynamics in drug-resistant epilepsy.

Sleep has important influences on focal interictal epileptiform discharges (IEDs), and the rates and spatial extent of IEDs are increased in non-rapid eye movement (NREM) sleep. In contrast, the influence of sleep on seizures is less clear and its effects on seizure topography are poorly documented. We evaluated the influences of NREM sleep on ictal spatiotemporal dynamics and contrasted these with interictal network dynamics. We included patients with drug-resistant focal epilepsy who underwent continuous intracranial EEG with depth electrodes. Patients were selected if they had 1-3 seizures from each vigilance state, wakefulness and NREM sleep, within a 48-hour window and under the same anti-seizure medication. A 10-min epoch of the interictal iEEG was selected per state, and IEDs were detected automatically. Twenty-five patients (13 females; 32.5±7.1 years) were included. The seizure onset pattern, duration, spatiotemporal propagation and latency of ictal high-frequency activity did not differ significantly between wakefulness and NREM sleep (all p>0.05). In contrast, IED rates and spatial distribution were increased in NREM compared to wakefulness (p<0.001, Cliff's d=0.48 and 0.49). The spatial overlap between vigilance states was higher for seizures (57.1±40.1%) than IEDs (41.7±46.2%) (p=0.001, Cliff's d=0.51). In contrast to its effects on IEDs, NREM sleep does not affect ictal spatiotemporal dynamics. This suggests that once the brain surpasses the seizure threshold, it will follow the underlying epileptic network irrespective of the vigilance state. These findings offer valuable insights into neural network dynamics in epilepsy and have important clinical implications for localizing seizure foci. This article is protected by copyright. All rights reserved.

Absence seizures in lesion-related epilepsy

BackgroundIn the new International League Against Epilepsy (ILAE) classification of seizure types, generalized seizures such as absence seizures (ASs) may originate from a focal point and rapidly spread to the bilaterally distributed brain network. Increasing evidence from animal and clinical studies has indicated that focal changes may occur prior to ASs; however, the relationship of ASs with epileptogenic lesions remains unclear.MethodsWe retrospectively collected and analyzed the clinical, imaging, and electrophysiological data of 16 patients who had ASs and structural lesions with seizure-free outcomes after lesion resection.ResultsIn semiology analysis, nine patients displayed focal onset; only two patients showed simple ASs, and seizure types other than ASs were observed in the remaining patients. On ictal electroencephalography (EEG), four patients showed bilateral synchronous symmetric 3 Hz generalized spike-wave discharges (GSWDs), and the remaining patients showed bilateral 1.5–2.5 Hz GSWDs. Moreover, most patients (13/16, 81.3%) exhibited focal features in addition to ASs, while interictal EEG was the same in 12 patients. Furthermore, on stereoelectroencephalogram (SEEG), 2/5 patients showed focal discharges before bilateral burst GSWDs. Additionally, all patients had structural lesions on imaging. In four typical AS patients, the lesions were located in deep brain regions. Notably, in 9 patients (9/16, 56%), the lesions were located in the posterior cortex. All patients underwent lesion resection and had seizure-free outcomes during follow-up, and intelligence quotient (IQ) also improved by 10.71 ± 3.90 one year after surgery.ConclusionsPatients with lesion-related epilepsy may present with ASs that have a focal onset and are associated with good surgical outcomes.

Heterogeneity of clinical features, EEG and brain imaging findings in anti-leucine-rich glioma-inactivated protein 1 autoimmune encephalitis: a retrospective case series study and review of the literature

BackgroundAnti-leucine-rich glioma-inactivated 1 (LGI-1) autoimmune encephalitis (AE), characterized by rapid decline of memory, seizures, and neuropsychiatric abnormalities, is a rare but devastating disorder. Early diagnosis and treatment are essential to prevent long-term sequelae. In this report, we provide a detailed description of clinical characteristics, laboratory test results, imaging, and electroencephalography (EEG) findings, as well as treatment responses of eight patients with anti-LGI-1 AE treated at our center.Case presentationAt the onset, all eight patients presented with confusion/memory deterioration, seizures (including faciobrachial dystonic seizures or other types of seizure), and behavioral changes such as hallucination, paranoia, and anxiety. Four patients were found with severe hyponatremia. Anti-LGI1 antibodies were detected in the cerebrospinal fluid and/or serum of all patients. For patients with faciobrachial dystonic seizures, no discernible scalp EEG change was detected, while EEG recording of patients experiencing other types of seizure showed focal slowing, focal epileptiform discharges, and focal onset seizures. All patients showed abnormal brain magnetic resonance imaging signals, mainly involving the mesial temporal lobe and the hippocampus. In addition, one patient also experienced fulminant cerebral edema during the acute phase of the illness. All patients received immunotherapy and anti-seizure medications and achieved good seizure control. Nevertheless, these patients continued to experience cognitive impairment during their long-term follow-ups.ConclusionsThe care of anti-LGI1 AE patients requires rapid evaluation, prompt initiation of immunotherapy, and long-term follow-up. The long-term presence of neurocognitive complications observed in these patients underline the importance of developing reliable biomarkers that can distinguish between different subtypes of this disease with heterogeneous clinico-electrographico-radiological features. Further research is needed to understand the molecular mechanisms underlying the heterogeneity, in order to facilitate development of more effective treatments for anti-LGI1 AE.

Relationship Between Electroencephalography and Seizure Outcome in Typical Absence Seizures in Children

BackgroundTypical absence seizures (TAS) are seen in idiopathic generalized epilepsy. Electroencephalography (EEG) contributes to syndrome characterization and counseling in an area where genetics does not currently play a significant role. Prominent interictal EEG findings are seen in juvenile absence epilepsy (JAE) and are thus thought to be associated with less favorable outcome in any TAS case despite lack of evidence. Our study evaluates EEG findings and their association with seizure outcomes in children with TAS. MethodsRetrospective cohort study of 123 children over 10 years with extensive EEG analysis and medical record review. Phone interviews ascertained longer-term outcomes. EEG reviewers were unaware of outcomes. ResultsTotal cohort included 123 children with phone review completed in 98. Median follow-up was 5 years 9 months. Seizure freedom was seen in 59% off antiseizure medicines (ASMs). Interictal findings included focal discharges in 29%, fragments of spike-wave (SW) discharges in 82.1%, and generalized interictal discharges in 63.4%. Interictal SW was more likely in those who slept (100%, 18 of 18) versus those who did not (57%, 60 of 105) (P < 0.001). Outcome analysis found no associations between focal or generalized interictal findings and seizure freedom, relapse off ASM, occurrence of other seizure types, or response to first ASM. ConclusionFocal and generalized interictal EEG discharges are common in children with TAS and are not associated with poorer outcomes. These interictal findings were traditionally associated with JAE rather than childhood absence epilepsy and were thus believed to be associated with potentially poorer outcome, which is probably not the case.

Predictive factors for successful vagus nerve stimulation in patients with refractory epilepsy: real-life insights from a multicenter study.

Vagus nerve stimulation (VNS) therapy is an established treatment for patients with drug-resistant epilepsy that reduces seizure frequency by at least 50% in approximately half of patients; however, the characteristics of the patients with the best response have not yet been identified. Thus, it is important to identify the profile of patients who would have the best response to guide early indications and better patient selection. This retrospective study evaluated vagus nerve stimulation (VNS) as an adjuvant therapy for patients with drug-resistant epilepsy from six epilepsy centers in Brazil. Data from 192 patients aged 2-66 years were analyzed, and all patients received at least 6 months of therapy to be included. Included patients were aged 2-66 years (25.6 ± 14.3), 105 (54.7%) males and 87 (45.8%) females. Median follow-up interval was 5 years (range, 2005-2018). Overall, the response rate (≥50% seizure reduction) after VNS implantation was 65.6% (126/192 patients). Most patients had 50-90% seizure reduction (60.9%) and nine patients became seizure-free. There were no serious complications associated with VNS implantation. The rate of a ≥ 50% seizure reduction response was significantly higher in patients with no history of neurosurgery. The presence of focal without generalized seizures and focal discharges on interictal EEG was associated with better response. Overall, etiological predictors of a better VNS response profile were tumors while a worse response to VNS was related to the presence of vascular malformations and Lennox-Gastaut Syndrome. We observed an association between a better response to VNS therapy no history of neurosurgery, focal interictal epileptiform activity, and focal seizure pattern. Additionally, it is important to highlight that age was not a determinant factor of the response, as children and adults had similar response rates. Thus, VNS therapy should be considered in both adults and children with DRE.

SCAF4 variants associated with focal epilepsy accompanied by multisystem disorders

PurposeThe SCAF4 gene encodes serine/arginine-related carboxyl-terminal domain-associated factor 4, which is highly expressed in the brain and potentially affects neurodevelopment. However, the functional significance of SCAF4 variants in human diseases remains unknown. MethodsTrio-based whole-exome sequencing was performed in three individuals with focal epilepsy. Bioinformatics tools were used to assess the pathogenicity of SCAF4 variants. Knockout scaf4a/b zebrafish were created using CRISPR-Cas9 used to validate the phenotype. ResultsSCAF4 variants were identified in three individuals from three unrelated families with focal epilepsy. All patients had focal seizures and focal discharges on EEG recordings, with intellectual disability or motor retardation, skeletal abnormalities, and one had cryptorchidism. However, no recurrence was observed after short-term ASMs treatment. The identified SCAF4 variants included two nonsense variants and one compound heterozygous variant, consisting of a missense and an in-frame variant. A low frequency of SCAF4 variants was observed in gnomAD in this study. Computational modelling has suggested that missense variants lead to functional impairments. In zebrafish, abnormal epileptiform signals, skeletal development, and neurodevelopment have been found in scaf4a/b knockout compared to wild-type zebrafish. ConclusionThese results indicate that SCAF4 is associated with focal epilepsy accompanied by multisystem disorders. Otherwise, the management of patients with SCAF4 variants requires more attention to multisystem involvement.

Spike count and morphology in the classification of epileptiform discharges.

The purpose of this study is to investigate the impact of Bergen Epileptiform Morphology Score (BEMS) and interictal epileptiform discharge (IED) candidate count in EEG classification. We included 400 consecutive patients from a clinical SCORE EEG database during 2013-2017 who had focal sharp discharges in their EEG, but no previous diagnosis of epilepsy. Three blinded EEG readers marked all IED candidates. BEMS and IED candidate counts were combined to classify EEGs as epileptiform or non-epileptiform. Diagnostic performance was assessed and then validated in an external dataset. Interictal epileptiform discharge (IED) candidate count and BEMS were moderately correlated. The optimal criteria to classify an EEG as epileptiform were either one spike at BEMS > = 58, two at > = 47, or seven at > = 36. These criteria had almost perfect inter-rater reliability (Gwet's AC1 0.96), reasonable sensitivity of 56-64%, and high specificity of 98-99%. The sensitivity was 27-37%, and the specificity was 93-97% for a follow-up diagnosis of epilepsy. In the external dataset, the sensitivity for an epileptiform EEG was 60-70%, and the specificity was 90-93%. Quantified EEG spike morphology (BEMS) and IED candidate count can be combined to classify an EEG as epileptiform with high reliability but with lower sensitivity than regular visual EEG review.

Peri-ictal EEG in infants with PRRT2-related self-limited infantile epilepsy.

Pathogenic PRRT2 variants cause self-limited (familial) infantile epilepsy (SeLIE), which is responsive to sodium channel blocking antiseizure medications. The interictal EEG is typically normal. We describe a cohort of infants with PRRT2-related SeLIE with striking peri-ictal EEG abnormalities. We included all infants diagnosed with PRRT2-related SeLIE during July 2020 to November 2021 at the Royal Children's Hospital, Melbourne. Clinical features and results of aetiologic investigations were collected from electronic medical records. All EEGs were reviewed independently by two epileptologists. Ten infants presented with focal seizures at a median age of 5 months (range: 3-6 months). Eight had a family history of epilepsy, paroxysmal kinesigenic dyskinesia (PKD) or hemiplegic migraine. Seven of the eight infants with an EEG performed within 24 h of the most recent seizure had epileptiform discharges. Their EEGs showed focal sharp waves, spikes, polyspikes or fast activity independently over the left and right temporo-occipital regions. Conversely, the two infants with last known seizure greater than 24 h prior to their EEG had no epileptiform discharges. Oxcarbazepine was commenced in two infants and was effective. Eight infants were initially treated with levetiracetam, and all were subsequently switched to oxcarbazepine due to ongoing seizures or side effects. Posterior polymorphic focal epileptiform discharges on a peri-ictal EEG recording are a feature of PRRT2-related SeLIE. This finding, particularly in the presence of a family history of infantile epilepsy, PKD or hemiplegic migraine, suggests a diagnosis of PRRT2-related SeLIE and has important treatment implications.

Recognition and epileptology of protracted CLN3 disease.

This study was undertaken to analyze phenotypic features of a cohort of patients with protracted CLN3 disease to improve recognition of the disorder. We analyzed phenotypic data of 10 patients from six families with protracted CLN3 disease. Haplotype analysis was performed in three reportedly unrelated families. Visual impairment was the initial symptom, with onset at 5-9 years, similar to classic CLN3 disease. Mean time from onset of visual impairment to seizures was 12 years (range = 6-41 years). Various seizure types were reported, most commonly generalized tonic-clonic seizures; focal seizures were present in four patients. Progressive myoclonus epilepsy was not seen. Interictal electroencephalogram revealed mild background slowing and 2.5-3.5-Hz spontaneous generalized spike-wave discharges. Additional interictal focal epileptiform discharges were noted in some patients. Age at death for the three deceased patients was 31, 31, and 52 years. Molecular testing revealed five individuals were homozygous for c.461-280_677 + 382del966, the "common 1-kb" CLN3 deletion. The remaining individuals were compound heterozygous for various combinations of recurrent pathogenic CLN3 variants. Haplotype analysis demonstrated evidence of a common founder for the common 1-kb deletion. Dating analysis suggested the deletion arose approximately 1500 years ago and thus did not represent cryptic familial relationship in this Australian cohort. We highlight the protracted phenotype of a disease generally associated with death in adolescence, which is a combined focal and generalized epilepsy syndrome with progressive neurological deterioration. The disorder should be suspected in an adolescent or adult patient presenting with generalized or focal seizures preceded by progressive visual loss. The common 1-kb deletion has been typically associated with classic CLN3 disease, and the protracted phenotype has not previously been reported with this genotype. This suggests that modifying genetic factors may be important in determining this somewhat milder phenotype and identification of these factors should be the subject of future research.

EEG Findings in a Pediatric Patient with 3q29 Microdeletion Syndrome (P13-1.005)

<h3>Objective:</h3> 3q29 microdeletion syndrome is a rare genetic disorder which results from interstitial microdeletion of a segment on the long arm of chromosome 3. The syndrome is characterized by neurodevelopmental and psychiatric manifestations including intellectual disability, autism spectrum disorder, anxiety, executive function deficits, and psychosis/schizophrenia. Systemic manifestations include ocular issues, gastrointestinal disorders, dental anomalies, and congenital heart defects. <h3>Background:</h3> We present a 7-year-old boy with a history of intellectual disability including delayed speech and fine motor abilities, and autism spectrum disorder, who presented with frequent and new onset of complete behavioral arrest, staring, grunting and pulling movements lasting several minutes that were described by his teachers. Spells did not progress to tonic-clonic activity and were not associated with urine loss. His physical examination revealed down slanted eyes, epicanthal folds, wide mouth, long and thin philtrum, thin upper lip and axial and appendulicar tone were decreased. EEG while off ASM revealed excessive beta activity of the background, frontally dominant generalized spike/polyspike and wave discharges, and focal spike/polyspike and wave activity seen independently over the left and right frontocentral regions. MRI showed reduced cerebral white matter hemispheric volume involving the frontoparietal lobes with no obvious seizure focus. He was subsequently started on levetiracetam, which resulted in a cessation of staring spells. <h3>Design/Methods:</h3> NA <h3>Results:</h3> NA <h3>Conclusions:</h3> Seizures have been reported in 13% of patients with 3q29 microdeletion syndrome and are generally mild and responsive to ASM. Previously reported EEG abnormalities in patients with 3q29 microdeletion syndrome include focal epileptiform discharges in the left occipital region and slow waves in the frontotemporal regions. To our knowledge, generalized spike/polyspike wave activity has not previously been reported in this syndrome. Whether the independent focal frontocentral epileptiform discharges represent a forme fruste of the generalized discharges, or the latter represent a rapid secondary bisynchrony phenomenon, remains to be determined. <b>Disclosure:</b> Dr. Sheikh has nothing to disclose. Dr. Nascimento has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Zogenix. The institution of Dr. Nascimento has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biocodex. Dr. Nascimento has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for AAN. The institution of Dr. Nascimento has received research support from Zogenix. The institution of Dr. Nascimento has received research support from Biocodex. The institution of Dr. Nascimento has received research support from Greenwich. Dr. Nascimento has received publishing royalties from a publication relating to health care. Dr. Nascimento has a non-compensated relationship as a Editorial Team Member with Neurology RFS that is relevant to AAN interests or activities. Dr. Nascimento has a non-compensated relationship as a Production Team with Neurology Podcast that is relevant to AAN interests or activities. Dr. Waite has nothing to disclose. Dr. Lam has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sage Therapeutics. Dr. Lam has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Neurona Therapeutics. Dr. Lam has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Cognito Therapeutics. The institution of Dr. Lam has received research support from Sage Therapeutics.

Auras in Persons with Focal and Generalized Epilepsy: Types and Patient Numbers from a Tertiary Level Epilepsy Center (P12-1.001)

<h3>Objective:</h3> We aimed to identify types and frequency of auras in patients with focal and generalized epilepsy. <h3>Background:</h3> The present-day knowledge of auras in persons with epilepsy (PWE) suggests a variety of experiences before seizure onset. A multitude of studies correlate them with focal epilepsy, although auras experienced by patients with generalized epilepsy have also been frequently reported. <h3>Design/Methods:</h3> This was a cross-sectional retrospective data analysis of 1505 PWE. We included patients who were diagnosed clinically as focal or generalized epilepsy along with corresponding changes on EEG and/or Long-Term Monitoring Evaluation (LTME). All patients in the study were inquired about consistent subjective feelings before seizure onset and these were classified as auras. <h3>Results:</h3> The database consists of 1505 patients out of which 1176 are diagnosed with focal and 253 diagnosed with generalized epilepsy. These patients were 47.2% male and 52.8% female, mean age 41.09±22.07 years. Available EEG/LTME results with focal discharges were seen in 214/1176 (18.1%) patients with focal epilepsy and generalized discharges in 127/253 (50%) patients with a diagnosis of generalized epilepsy. Auras were found to be more common in patients in the focal epilepsy (27%) than generalized epilepsy (16%). Most common auras reported in focal epilepsy included feeling of confusion (21%), visual symptoms (18%) and somatosensory (11%). In generalized epilepsy, non-specific auras were most commonly noted including, feeling of confusion (30%), dizziness (25%) and somatosensory (10%). Vague and non-descript auras were reported in 19% of patients with focal epilepsy and 25% of those with generalized epilepsy. <h3>Conclusions:</h3> Approximately one-third of patients with EEG confirmed diagnosis of focal epilepsy experience auras. Although less frequently, generalized epilepsy patients also report auras. Use of standardized terminology for identifying auras might help address the variations reported. More studies are needed to identify the electrophysiological phenomena associated with them. <b>Disclosure:</b> Mr. Asghar has nothing to disclose. Dr. Naz has nothing to disclose. Dr. Ramsey-Williams has nothing to disclose. Dr. Sheikh has nothing to disclose. Dr. Saleem has nothing to disclose. Dr. Pervez has nothing to disclose. Dr. Ali has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for ABPN. Dr. Riaz has nothing to disclose.

Deep learning-based automated detection and multiclass classification of focal interictal epileptiform discharges in scalp electroencephalograms

Detection and spatial distribution analyses of interictal epileptiform discharges (IEDs) are important for diagnosing, classifying, and treating focal epilepsy. This study proposes deep learning-based models to detect focal IEDs in electroencephalography (EEG) recordings of the frontal, temporal, and occipital scalp regions. This study included 38 patients with frontal (n = 15), temporal (n = 13), and occipital (n = 10) IEDs and 232 controls without IEDs from a single tertiary center. All the EEG recordings were segmented into 1.5-s epochs and fed into 1- or 2-dimensional convolutional neural networks to construct binary classification models to detect IEDs in each focal region and multiclass classification models to categorize IEDs into frontal, temporal, and occipital regions. The binary classification models exhibited accuracies of 79.3–86.4%, 93.3–94.2%, and 95.5–97.2% for frontal, temporal, and occipital IEDs, respectively. The three- and four-class models exhibited accuracies of 87.0–88.7% and 74.6–74.9%, respectively, with temporal, occipital, and non-IEDs F1-scores of 89.9–92.3%, 84.9–90.6%, and 84.3–86.0%; and 86.6–86.7%, 86.8–87.2%, and 67.8–69.2% for the three- and four-class (frontal, 50.3–58.2%) models, respectively. The deep learning-based models could help enhance EEG interpretation. Although they performed well, the resolution of region-specific focal IED misinterpretations and further model improvement are needed.

Seizures in Neurosarcoidosis (P9-5.011)

<h3>Objective:</h3> To determine how seizures impact the management of neurosarcoidosis and affect long-term outcomes. <h3>Background:</h3> Though neurosarcoidosis can injure the cerebral cortex via several mechanisms, seizures are uncommonly reported as a clinical manifestation of the disease (4–15%) and have been previously associated with a more severe course. <h3>Design/Methods:</h3> Patients with a diagnosis of neurosarcoidosis were included in this retrospective cohort analysis if seizures were a clinical manifestation of their disease. <h3>Results:</h3> Seizures were present in 26/216 (12.0%) patients and were an initial manifestation of neurosarcoidosis in 11/26 (42.3%). None had a pre-existing seizure disorder. Semiologies were reported in 23: generalized in 12/23 (52.2%), focal in 9/23 (39.1%), and both in 2/23 (8.7%). Status epilepticus occurred in 6/26 (23.1%); 2 (7.7%) were intubated. MRIs were obtained in 25 with cerebral parenchymal lesions (18/25, 72.0%) being the most common radiographic accompaniment, followed by leptomeningitis (13/25, 52.0%) and pachymeningitis (10/25, 40.0%). EEGs showed focal slowing in 12/19 (63.1%), focal epileptiform discharges in 5/19 (26.3%), no abnormalities in 4/19 (21.1%), generalized slowing in 2/19 (10.5%), and epileptiform discharges of unclear distribution in 1/19 (5.3%). No patients had generalized epileptiform discharges. Seizures were controlled in 22/26 (84.6%) compliant with antiseizure medicines (ASMs). Most (18/26, 69.2%) required only 1 medicine for control with levetiracetam being beneficial in 22/22 (100%) trialed. 17/25 (68.0%) had 6 or fewer lifetime seizures. 2/26 (7.7%) were ultimately weaned off ASMs. 13/26 (50.0%) required two or more lines of immunosuppression, all of whom received biologic treatments. The average last mRS was 2.0. No patients died as a result of seizures. Median follow-up of 68.4 months. <h3>Conclusions:</h3> Seizures in neurosarcoidosis occur most commonly with cerebral parenchymal lesions and are relatively easy to control with ASMs, but the accompanying neuroinflammation is often challenging to treat with a high reliance on biologic therapies for management. <b>Disclosure:</b> Dr. Ngo has nothing to disclose. Dr. Hutto has nothing to disclose.

Nichtläsionelle Epilepsie – ein Fallbericht aus der Erwachsenen-Neurologie

AbstractWe report the case of a patient with nonlesional, pharmacoresistant epilepsy. Bilateral synchronous discharges as well as focal discharges were identified on electroencephalogram (EEG). After non-invasive and invasive presurgical evaluation, a probable epileptogenic zone was identified with concordant results of focal origin involvement of the left temporal pole. Resective epilepsy surgery provided seizure freedom (last follow-up at 12 months). The case nicely illustrates that bilateral synchronous discharges or/and a lack of lesions on neuroimaging are not contraindications to presurgical evaluation of epilepsy, which on the contrary should be offered to all patients with pharmacoresistant epilepsy. The case also illustrates the importance of combining electrophysiological, imaging, and neuropsychological information to guide intracranial EEG placement and improve postsurgical outcome.

Post-traumatic epilepsy in Cameroon: a retrospective study in a referral hospital

BackgroundPost-traumatic epilepsy is defined as the onset of at least one seizure beyond the first week following a traumatic brain injury (TBI). High prevalence of TBI in our setting may contribute to the burden of epilepsy in adult population. This is a retrospective review of medical records of patients admitted from January 1st, 2010 to December 31st, 2019) at Douala General Hospital. We included patients aged ≥ 18 years with seizure onset at least one week after TBI. Incomplete files and previously known epilepsy were excluded. Data on sociodemography, clinical and para-clinical features, treatment and outcome were analysed using R software version 36.2.ResultsWe finally included 65 patients with post-traumatic epilepsy among 993 medical records of epilepsy. The mean age was 35.1 ± 12.6 years, with 64.6% of male. Road traffic accident was the main aetiology of brain trauma (78.5%), resulting in haemorrhagic contusions (21.5%), sub-dural haematoma (15.4%), and diffuse axonal lesions (15.4%) mainly. Seizure onset was within 2 years post-trauma in 73.8% of cases. Generalized tonic–clonic seizures were the commonest seizure’s type. Electroencephalogram was abnormal in 81%, including 47% of focal discharges. Antiepileptic drugs were mainly sodium valproate, carbamazepine, and phenobarbital. Seizure freedom was obtained in 67.7% of cases.ConclusionsPost-traumatic epilepsy is a heterogeneous, frequent and often disabling complication of traumatic brain injury. Road traffic accident is the main cause of brain trauma. It affects a young and active population. About half of cases presented GTCS. With antiepileptic drugs, more than two-thirds of patients become seizure-free.

The diagnostic value of electroencephalography in pediatric patients presenting with syncope Running title: The yield of electroencephalography in pediatric syncope

Aim: In the investigation of the diagnosis of pediatric syncope, it was aimed to evaluate the rate of abnormal EEG findings and the diagnostic yield of the EEG in the electroencephalography (EEG) taken following their neurological examination. Materials and Methods: EEG records of 332 patients younger than 18 years of age who presented to the pediatric neurology outpatient clinic with syncope were retrospectively analyzed. The EEG results were classified as normal and abnormal. Based on the abnormal EEG results, four subgroups were formed as focal epileptiform discharge, generalized epileptiform discharge, focal slowing and generalized slowing. Abnormal EEG results were categorized according to age and gender. Results: Of the cases included in the study, 195 (58.7%) were female and 137 (41.3%) were male. The mean age of the patients was calculated as 12.67±3.21 years. Analysis of the EEG results revealed that 92.5% were normal and 7.53% were abnormal. The most common abnormal EEG finding was focal slowing, which was detected in 12 (3.6%) patients, followed by focal epileptiform discharge which was detected in eight (2.4%) and generalized epileptiform discharge which was detected in five (1.5%) patients. Conclusion: EEG should not be routinely performed to evaluate the diagnosis of pediatric syncope. Therefore, EEG should be performed only on patients to be selected based on their medical history and the results of their neurological examination. In this way, it will be possible to derive more benefits out of EEG and to reduce the associated medical costs.

Isolated Unilateral EEG Findings in Juvenile Myoclonic Epilepsy: A Case Report

Juvenile myoclonic epilepsy (JME) has well-defined clinical and electrophysiological features. On the other hand, large case series have shown that focal and asymmetrical discharges may accompany generalized epileptiform activities in JME. Although it is known that these non-generalized electrophysiological findings do not exclude the diagnosis of this syndrome, some findings may create confusion in the differential diagnosis. In this case report, a case of JME with electroencephalographic findings characterized by isolated unilateral epileptiform activities without typical generalized discharges was discussed. The current case clinically presented with involuntary jerk movements in the bilateral upper extremities. It has been determined that these movements are uni/bilateral myoclonic beats based on home video recordings. Metabolic, toxic and structural problems were excluded in the investigations for the etiology of myoclonus. In the electrophysiological examination performed for epileptic processes, epileptiform discharges localized to the isolated right hemisphere were observed. JME was considered primarily due to clinical findings in the patient, and effective seizure control was achieved in a 4-year follow-up under anti-seizure treatment. The peculiarity of the case is the presence of electrophysiology recordings of isolated unilateral epileptiform activity during the 4-year follow-up period. It should be emphasized that there is no case of JME diagnosed with isolated unilateral epileptiform activity in the absence of generalized spike-slow waves or multiple spike-slow waves in the literature.