Centromedian region thalamic responsive neurostimulation mitigates idiopathic generalized and multifocal epilepsy with focal to bilateral tonic-clonic seizures.

OBJECTIVE: Although >30% of epilepsy patients have drug-resistant epilepsy (DRE), typically those with generalized or multifocal disease have not traditionally been considered surgical candidates. Responsive neurostimulation (RNS) of the centromedian (CM) region of the thalamus now appears to be a promising therapeutic option for this patient population. We present outcomes following CM RNS for 13 patients with idiopathic generalized epilepsy (IGE) and eight with multifocal onsets that rapidly generalize to bilateral tonic-clonic (focal to bilateral tonic-clonic [FBTC]) seizures. METHODS: A retrospective review of all patients undergoing bilateral CM RNS by the senior author through July 2022 were reviewed. Electrodes were localized and volumes of tissue activation were modeled in Lead-DBS. Changes in patient seizure frequency were extracted from electronic medical records. RESULTS: Twenty-one patients with DRE underwent bilateral CM RNS implantation. For 17 patients with at least 1 year of postimplantation follow-up, average seizure reduction from preoperative baseline was 82.6% (SD = 19.0%, median = 91.7%), with 18% of patients Engel class 1, 29% Engel class 2, 53% Engel class 3, and 0% Engel class 4. There was a trend for average seizure reduction to be greater for patients with nonlesional FBTC seizures than for other patients. For patients achieving at least Engel class 3 outcome, median time to worthwhile seizure reduction was 203.5 days (interquartile range = 110.5-343.75 days). Patients with IGE with myoclonic seizures had a significantly shorter time to worthwhile seizure reduction than other patients. The surgical targeting strategy evolved after the first four subjects to achieve greater anatomic accuracy. SIGNIFICANCE: Patients with both primary and rapidly generalized epilepsy who underwent CM RNS experienced substantial seizure relief. Subsets of these patient populations may particularly benefit from CM RNS. The refinement of lead targeting, tuning of RNS system parameters, and patient selection are ongoing areas of investigation.

Deep net detection and onset prediction of electrographic seizure patterns in responsive neurostimulation.

OBJECTIVE: Managing the progress of drug-resistant epilepsy patients implanted with the Responsive Neurostimulation (RNS) System requires the manual evaluation of hundreds of hours of intracranial recordings. The generation of these large amounts of data and the scarcity of experts' time for evaluation necessitate the development of automatic tools to detect intracranial electroencephalographic (iEEG) seizure patterns (iESPs) with expert-level accuracy. We developed an intelligent system for identifying the presence and onset time of iESPs in iEEG recordings from the RNS device. METHODS: An iEEG dataset from 24 patients (36 293 recordings) recorded by the RNS System was used for training and evaluating a neural network model (iESPnet). The model was trained to identify the probability of seizure onset at each sample point of the iEEG. The reliability of the net was assessed and compared to baseline methods, including detections made by the device. iESPnet performance was measured using balanced accuracy and the F1 score for iESP detection. The prediction time was assessed via both the error and the mean absolute error. The model was evaluated following a hold-one-out strategy, and then validated in a separate cohort of 26 patients from a different medical center. RESULTS: iESPnet detected the presence of an iESP with a mean accuracy value of 90% and an onset time prediction error of approximately 3.4 s. There was no relationship between electrode location and prediction outcome. Model outputs were well calibrated and unbiased by the RNS detections. Validation on a separate cohort further supported iESPnet applicability in real clinical scenarios. Importantly, RNS device detections were found to be less accurate and delayed in nonresponders; therefore, tools to improve the accuracy of seizure detection are critical for increasing therapeutic efficacy. SIGNIFICANCE: iESPnet is a reliable and accurate tool with the potential to alleviate the time-consuming manual inspection of iESPs and facilitate the evaluation of therapeutic response in RNS-implanted patients.

Responsive neurostimulation of the thalamus improves seizure control in idiopathic generalised epilepsy: initial case series.

OBJECTIVES: Up to 40% of patients with idiopathic generalised epilepsy (IGE) are drug resistant and potentially could benefit from intracranial neuromodulation of the seizure circuit. We present outcomes following 2 years of thalamic-responsive neurostimulation for IGE. METHODS: Four patients with pharmacoresistant epilepsy underwent RNS System implantation in the bilateral centromedian (CM) nucleus region. Electrophysiological data were extracted from the clinical patient data management system and analysed using a specialised platform (BRAINStim). Postoperative visualisation of electrode locations was performed using Lead-DBS. Seizure outcomes were reported using the Engel scale. RESULTS: Patients experienced a 75%-99% reduction in seizure frequency with decreased seizure duration and severity (Engel class IB, IC, IIA and IIIA), as well as significant improvements in quality of life. Outcomes were durable through at least 2 years of therapy. Detection accuracy for all patients overall decreased over successive programming epochs from a mean of 96.5% to 88.3%. Most electrodes used to deliver stimulation were located in the CM (7/10) followed by the posterior dorsal ventral lateral (2/2), posterior ventral posterior lateral (3/4) and posterior ventral ventral lateral (2/3). In all patients, stimulation varied from 0.2 to 2.0 mA and amplitude only increased over successive epochs. The raw percentage of intracranial electroencephalography recordings with stimulations delivered to electrographic seizures was 24.8%, 1.2%, 7.6% and 8.8%. CONCLUSION: Closed-loop stimulation of the CM region may provide significant improvement in seizure control and quality of life for patients with drug-resistant IGE. Optimal detection and stimulation locations and parameters remain an active area of investigation for accelerating and fine-tuning clinical responses.

Preferences and experiences of women with epilepsy regarding sexual and reproductive healthcare provision.

RATIONALE: Women with epilepsy (WWE) have unique disease-specific considerations regarding their sexual and reproductive health (SRH), which impact decision-making around pregnancy and contraception. Understanding their perspectives, preferences, and experiences regarding SRH care contributes to optimizing patient-centered clinical practice. METHODS: We conducted individual semi-structured interviews with WWE aged 18-45 years, exploring their SRH care experiences and preferences. We audio-recorded and transcribed all interviews. Two coders used both inductive and deductive strategies to perform thematic analysis and identify key themes and representative quotes. RESULTS: Twenty WWE completed interviews (median age 23 years; range 18-43 years). Key themes included: 1) SRH counseling from neurologists often did not occur, was limited in scope, or contained misinformation, especially during adolescence and early adulthood. In particular, participants felt that they received poor counseling about contraception, fertility, folic acid, and teratogenic medications, which impacted their reproductive decision-making. 2) WWE report fragmented care between their neurologist and other SRH providers. 3) WWE prefer that their neurologists initiate routine comprehensive discussions about SRH. 4) Conversations about SRH should begin in adolescence and include private confidential discussions between neurologists and WWE. 5) Successful SRH conversations between neurologists and WWE involve detailed information, reassurance, and support for the patient's reproductive goals. CONCLUSION: WWE desire comprehensive, coordinated counseling and care regarding SRH and epilepsy, and often experience suboptimal SRH care. Better understanding of the SRH needs, preferences, and experiences of WWE will help inform interventions to optimize patient-centered SRH counseling and care by healthcare professionals, especially during adolescence.

Concurrent brain-responsive and vagus nerve stimulation for treatment of drug-resistant focal epilepsy.

OBJECTIVE: Clinical trials of a brain-responsive neurostimulator, RNS® System (RNS), excluded patients with a vagus nerve stimulator, VNS® System (VNS). The goal of this study was to evaluate seizure outcomes and safety of concurrent RNS and VNS stimulation in adults with drug-resistant focal-onset seizures. METHODS: A retrospective multicenter chart review was performed on all patients with an active VNS and RNS who were treated for a minimum of 6 months with both systems concurrently. Frequency of disabling seizures at baseline before RNS, at 1 year after RNS placement, and at last follow-up were used to calculate the change in seizure frequency after treatment. Data on adverse events and complications related to each device were collected. RESULTS: Sixty-four patients from 10 epilepsy centers met inclusion criteria. All but one patient received RNS after VNS. The median follow-up time after RNS implantation was 28 months. Analysis of the entire population of patients with active VNS and RNS systems revealed a median reduction in seizure frequency at 1 year post-RNS placement of 43% with a responder rate of 49%, and at last follow-up a 64% median reduction with a 67% responder rate. No negative interactions were reported from the concurrent use of VNS and RNS. Stimulation-related side-effects were reported more frequently in association with VNS (30%) than with RNS (2%). SIGNIFICANCE: Our findings suggest that concurrent treatment with VNS and RNS is safe and that the addition of RNS to VNS can further reduce seizure frequency.

Sexual and reproductive health concerns of women with epilepsy beginning in adolescence and young adulthood.

BACKGROUND: Women with epilepsy (WWE) have potentially unique concerns regarding their sexual and reproductive health (SRH). Prior studies of WWE have focused narrowly on pregnancy and preconception experiences, and have not addressed concerns of nulliparous adolescent and young adult women not actively seeking pregnancy. METHODS: We conducted individual semi-structured interviews with WWE 18-45 years of age. We sampled to maximize diversity of age and parity, and intentionally included many adolescent and young adult nulliparous women not actively planning pregnancy. Interviews broadly addressed participants' SRH concerns and experiences. Interviews were audio-recorded and transcribed. Two coders performed qualitative analysis using thematic analysis with deductive and inductive approaches. RESULTS: Twenty WWE (median age 23 years, range 18-43 years) completed interviews. Twelve were nulliparous, six had children, one had a history of miscarriage only, and two were currently pregnant. WWE's narratives revealed significant concerns about family planning and reproductive health in the context of epilepsy, including: 1) seizures endangering pregnancies and children 2) teratogenic effects of antiseizure medication, 3) heritability of epilepsy, 4) antiseizure medication and epilepsy impacting fertility, and 5) interactions between antiseizure medication and contraception. CONCLUSION: WWE, including nulliparous adolescent and young adult women who are not actively planning pregnancy, have significant concerns about how their epilepsy interacts with SRH. SRH counseling for WWE should begin during adolescence and be incorporated into the transition process from pediatric to adult healthcare. Insights from WWE may aid in the creation of relevant patient-facing educational resources as well as provider-facing training and tools to meaningfully support the reproductive decision-making of WWE throughout their childbearing years.

Comparison of medial distal tibial angle in EOS imaging and weightbearing X-ray.

BACKGROUND: The medial distal tibial angle (MDTA) is used for measurement of ankle alignment. Standard to measure MDTA is weightbearing mortise view. EOS imaging becomes more popular for limb alignment analysis using low-dose radiation. As MDTA might vary in EOS, comparison between both radiographic techniques has been performed. METHODS: MDTA was compared between both techniques in 43 cases by defining the mechanical tibial axis in different ways (X-ray low, EOS low, EOS high). For each method MDTA, intra- and interobserver reliability has been compared. RESULTS: The correlation between the different methods were measured by ICC (intraclass coefficient) and were ICC 0.86 (X-ray low/EOS low), ICC 0.85 (X-ray low/EOS high) and ICC 0.97 (EOS low/EOS high). Intra- and interobserver reliability were in each case ICC > 0.95. CONCLUSION: ICC showed a substantial to excellent agreement between all methods. EOS is appropriate to determine MDTA and can be used for assessment of coronar deformities of the distal tibia.

Outcomes in three cases after brivaracetam treatment during pregnancy.

BACKGROUND: Use of certain antiseizure drugs (ASDs) during pregnancy increases the risk of major congenital malformations, while less is known about newer ASDs. Based on the safety of levetiracetam, brivaracetam may be similarly safe in pregnancy; however, no cases have been published to date. AIMS OF THE STUDY: We retrospectively identified three women with epilepsy treated with brivaracetam during pregnancy and described the maternal and neonatal outcomes. METHODS: We reviewed the patients' medical records as well as the linked medical records of their infants to identify complications during pregnancy and delivery, neonatal complications, and evidence of major/minor congenital malformations. RESULTS: Our series included one woman with idiopathic generalized epilepsy and two women with focal epilepsy (brivaracetam doses ranging from 50 to 200 mg daily). One patient with focal epilepsy experienced breakthrough seizures, and lamotrigine was added to brivaracetam. The other women had no neurologic complications during pregnancy. All three women had full-term deliveries without significant complications. Three healthy infants were born with Apgar scores of 9 and 9 and no major congenital malformations. Three minor congenital malformations were observed in two infants. CONCLUSIONS: While the absence of major congenital malformations in these cases is encouraging, further data are needed to determine the safety of brivaracetam in pregnancy.

Diagnostic accuracy of paroxysmal spells: Clinical history versus observation.

Our goal was to evaluate how accurate neurologists are at differentiating between different paroxysmal events based on clinical history versus observation of the spell in question. Forty-seven neurologists reviewed 12 clinical histories and videos of recorded events of patients admitted in the Epilepsy Monitoring Unit (EMU). They were asked to diagnose events as epileptic seizures, non-epileptic behavioral spells (NEBS), or other physiologic events as well as rate their confidence in their diagnosis. The median diagnostic accuracy for all paroxysmal events was 67% for clinical history and 75% for observation (p=.001). This was largely due to the difference in accuracy within the subgroup of patients with NEBS (67% history vs. 83% observation, p<.001). There were trends for higher diagnostic accuracy and increased inter-rater agreement with higher levels of training. Physicians with higher levels of training were more confident with diagnosis based on observation. In summary, reviewing videos of paroxysmal spells may improve diagnostic accuracy and enhance the evaluation of patients. Neurologists at all levels of training should encourage the recording and review of videos of recurrent spells to aid in medical decision-making especially when there is high concern that the spells in question are NEBS.

Hippocampal barques and their manifestation as 14&6 Hz positive spikes during sleep.

OBJECTIVE: This study investigates variations in hippocampal barque occurrence during sleep and compares findings to respective variations of their scalp manifestation as 14&6/sec positive spikes. METHODS: From 11 epilepsy patients, 12 non-epileptogenic hippocampi with barques were identified for this study. Using the first seizure-free whole-night sleep stereo-encephalography (sEEG) recording, we performed sleep staging and measured the occurrence of barques and 14&6/sec positive spikes variants. RESULTS: Hippocampal barques (total count: 9,183; mean count per record: 765.2 ± 251.2) occurred predominantly during non-rapid eye movement (NREM) II sleep (total: 5,744; mean: 478.6 ± 176.1; 62.2 ± 6.0%) and slow-wave sleep (SWS) (total: 2,950; mean: 245.83 ± 92.9; 32.0 ± 6.2%), with rare to occasional occurrence in NREM I (total: 85; mean: 7.0 ± 2.8; 0.9 ± 0.4%), rapid eye movement (REM) (total: 153; mean: 12.75 ± 4.0; 1.7 ± 0.6) and wakefulness (total: 251; mean: 20.9 ± 6.3; 2.9 ± 0.9%). Barque rate increased during SWS (mean: 2.7 ± 1.0 per min) compared to NREM II (2.2 ± 1.0 per min) and other states (wakefulness: 0.1 ± 0.0 per min; NREM I: 0.3 ± 0.1 per min; REM: 0.1 ± 0.0 per min). The 14&6/sec positive spikes variant (total count: 2,406; mean: 343.7 ± 106.7) was present in NREM II (total: 2,059; mean: 249.1 ± 100.2, 84.9 ± 3.6%) and SWS (total: 347; mean: 49.5 ± 12.8, 15.0 ± 3.6%) stages, and absent from the rest of sleep and wakefulness. While all 14&6/sec positive spikes correlated with barques, only 44.7 ± 6.1% of barques manifested as 14&6/sec positive spikes. CONCLUSIONS: Hippocampal barques are predominant in NREM II and SWS, and tend to increase their presence during SWS. Their scalp manifestation as 14&6/sec positive spikes is confounded by wakefulness, REM and NREM I stages, and "masked" by the co-occurrence of NREM II and SWS slow waves, and overlapping reactive micro-arousal elements. SIGNIFICANCE: Our study highlighted the overnight profile of hippocampal barques, in relation to the respective profile of their scalp manifestation, the 14&6/sec positive spikes variant.

Specific afterdischarge properties can enhance the clinical utility of electrical stimulation mapping during intracranial monitoring.

OBJECTIVE: Extraoperative electrical cortical stimulation (ECS) facilitates defining the seizure onset zone (SOZ) and eloquent cortex. The clinical relevance of stimulation-induced afterdischarges (ADs) is not well defined. METHODS: Fifty-five patients who underwent intracranial electroencephalogram evaluations with ECS were retrospectively identified. ADs were identified in these recordings and categorized by pattern, location, and association with stimulation-induced seizures. RESULTS: ADs were generated in 1774/9285 (19%) trials. Rhythmic spikes and irregular ADs within the stimulated bipolar contact pair were predictive of location within the SOZ compared to non-epileptogenic/non-irritative cortex (rhythmic spikes OR 2.24, p = 0.0098; irregular OR 1.39; p = 0.013). ADs immediately preceding stimulated seizures occurred at lower stimulation intensity thresholds compared to other stimulations (mean 2.94 ± 0.28 mA vs. 4.16 ± 0.05 mA respectively; p = 0.0068). CONCLUSIONS: Changes in AD properties can provide clinically relevant data in extraoperative stimulation mapping. SIGNIFICANCE: Although not exclusive to the SOZ, the generation of rhythmic spikes may suggest that a stimulation location is within the SOZ, while decreased stimulation intensity thresholds eliciting ADs may alert clinicians to a heightened probability of seizure generation with subsequent stimulation.

Development of a stereo-EEG based seizure matching system for clinical decision making in epilepsy surgery.

Objective.The proportion of patients becoming seizure-free after epilepsy surgery has stagnated. Large multi-center stereo-electroencephalography (SEEG) datasets can allow comparing new patients to past similar cases and making clinical decisions with the knowledge of how cases were treated in the past. However, the complexity of these evaluations makes the manual search for similar patients impractical. We aim to develop an automated system that electrographically and anatomically matches seizures to those in a database. Additionally, since features that define seizure similarity are unknown, we evaluate the agreement and features among experts in classifying similarity.Approach.We utilized 320 SEEG seizures from 95 consecutive patients who underwent epilepsy surgery. Eight international experts evaluated seizure-pair similarity using a four-level similarity score. As our primary outcome, we developed and validated an automated seizure matching system by employing patient data marked by independent experts. Secondary outcomes included the inter-rater agreement (IRA) and features for classifying seizure similarity.Main results.The seizure matching system achieved a median area-under-the-curve of 0.76 (interquartile range, 0.1), indicating its feasibility. Six distinct seizure similarity features were identified and proved effective: onset region, onset pattern, propagation region, duration, extent of spread, and propagation speed. Among these features, the onset region showed the strongest correlation with expert scores (Spearman's rho = 0.75,p< 0.001). Additionally, the moderate IRA confirmed the practicality of our approach with an agreement of 73.9% (7%), and Gwet's kappa of 0.45 (0.16). Further, the interoperability of the system was validated on seizures from five centers.Significance.We demonstrated the feasibility and validity of a SEEG seizure matching system across patients, effectively mirroring the expertise of epileptologists. This novel system can identify patients with seizures similar to that of a patient being evaluated, thus optimizing the treatment plan by considering the results of treating similar patients in the past, potentially improving surgery outcome.

Prognostic value of the 5-SENSE Score to predict focality of the seizure-onset zone as assessed by stereoelectroencephalography: a prospective international multicentre validation study.

Introduction: Epilepsy surgery is the only curative treatment for patients with drug-resistant focal epilepsy. Stereoelectroencephalography (SEEG) is the gold standard to delineate the seizure-onset zone (SOZ). However, up to 40% of patients are subsequently not operated as no focal non-eloquent SOZ can be identified. The 5-SENSE Score is a 5-point score to predict whether a focal SOZ is likely to be identified by SEEG. This study aims to validate the 5-SENSE Score, improve score performance by incorporating auxiliary diagnostic methods and evaluate its concordance with expert decisions. Methods and analysis: Non-interventional, observational, multicentre, prospective study including 200 patients with drug-resistant epilepsy aged ≥15 years undergoing SEEG for identification of a focal SOZ and 200 controls at 22 epilepsy surgery centres worldwide. The primary objective is to assess the diagnostic accuracy and generalisability of the 5-SENSE in predicting focality in SEEG in a prospective cohort. Secondary objectives are to optimise score performance by incorporating auxiliary diagnostic methods and to analyse concordance of the 5-SENSE Score with the expert decisions made in the multidisciplinary team discussion. Ethics and dissemination: Prospective multicentre validation of the 5-SENSE score may lead to its implementation into clinical practice to assist clinicians in the difficult decision of whether to proceed with implantation. This study will be conducted in accordance with the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans (2014). We plan to publish the study results in a peer-reviewed full-length original article and present its findings at scientific conferences. Trial registration number: NCT06138808.

The endoscopic anterior transmaxillary temporal pole approach for mesial temporal lobe epilepsies: a feasibility study.

OBJECTIVE: In mesial temporal lobe epilepsy (MTLE), the ideal surgical approach to achieve seizure freedom and minimize morbidity is an unsolved question. Selective approaches to mesial temporal structures often result in suboptimal seizure outcomes. The authors report the results of a pilot study intended to evaluate the clinical feasibility of using an endoscopic anterior transmaxillary (eATM) approach for minimally invasive management of MTLEs. METHODS: The study is a prospectively collected case series of four consecutive patients who underwent the eATM approach for the treatment of MTLE and were followed for a minimum of 12 months. All participants underwent an epilepsy workup and surgical care at a tertiary referral comprehensive epilepsy center and had medically refractory epilepsy. The noninvasive evaluations and intracranial recordings of these patients confirmed the presence of anatomically restricted epileptogenic zones located in the mesial temporal structures. Data on seizure freedom at 1 year, neuropsychological outcomes, diffusion tractography, and adverse events were collected and analyzed. RESULTS: By applying the eATM technique and approaching the far anterior temporal lobe regions, mesial-basal resections of the temporal polar areas and mesial temporal structures were successfully achieved in all patients (2 with left-sided approaches, 2 with right-sided approaches). No neurological complications or neuropsychological declines were observed. All 4 patients achieved Engel class Ia outcome up to the end of the follow-up period (19, 15, 14, and 12 months). One patient developed hypoesthesia in the left V2 distribution but there were no other adverse events. The low degree of white matter injury from the eATM approach was analyzed using high-definition fiber tractography in 1 patient as a putative mechanism for preserving neuropsychological function. CONCLUSIONS: The described series demonstrates the feasibility and potential safety profile of a novel approach for medically refractory MTLE. The study affirms the feasibility of performing efficacious mesial temporal lobe resections through an eATM approach.

Does immune suppression during stress occur to promote physical performance?

Two adaptationist hypotheses have been proposed to explain why stress, particularly elevation of stress hormones (i.e. glucocorticoids), tends to suppress immune functions. One is that immune suppression represents efforts to minimize autoimmune responses to self-antigens released as organisms cope with stressors (i.e. the autoimmune-avoidance hypothesis). The other is that immune suppression occurs to promote a shunting of resources to life processes more conducive to survival of the stressor (i.e. the re-allocation hypothesis). Here in wild-caught house sparrows (Passer domesticus), we tested the second hypothesis, asking whether sustained elevation of baseline glucocorticoids, due to captivity, caused a greater rate of decline in immune functions than flight performance. A greater decline in immune functions than flight performance would support the re-allocation hypothesis. As in previous studies, we found that captivity tended to alter baseline corticosterone, suggesting that house sparrows experience captivity as a stressor. Captivity also affected several constitutive and induced innate immune metrics: bacterial (Escherichia coli) killing activity of blood and oxidative burst of leukocytes both changed in a manner consistent with immune disregulation. In contrast, breast muscle size and vertical flight (hovering) duration improved over captivity. Collectively, these changes provide indirect support for the re-allocation hypothesis, although within individuals, changes in immune and physical performance were unrelated.

Interictal SEEG Resting-State Connectivity Localizes the Seizure Onset Zone and Predicts Seizure Outcome.

Localization of epileptogenic zone currently requires prolonged intracranial recordings to capture seizure, which may take days to weeks. The authors developed a novel method to identify the seizure onset zone (SOZ) and predict seizure outcome using short-time resting-state stereotacticelectroencephalography (SEEG) data. In a cohort of 27 drug-resistant epilepsy patients, the authors estimated the information flow via directional connectivity and inferred the excitation-inhibition ratio from the 1/f power slope. They hypothesized that the antagonism of information flow at multiple frequencies between SOZ and non-SOZ underlying the relatively stable epilepsy resting state could be related to the disrupted excitation-inhibition balance. They found flatter 1/f power slope in non-SOZ regions compared to the SOZ, with dominant information flow from non-SOZ to SOZ regions. Greater differences in resting-state information flow between SOZ and non-SOZ regions are associated with favorable seizure outcome. By integrating a balanced random forest model with resting-state connectivity, their method localized the SOZ with an accuracy of 88% and predicted the seizure outcome with an accuracy of 92% using clinically determined SOZ. Overall, this study suggests that brief resting-state SEEG data can significantly facilitate the identification of SOZ and may eventually predict seizure outcomes without requiring long-term ictal recordings.

EEG Findings in Coronavirus Disease.

PURPOSE: Neurologic manifestations of coronavirus disease (COVID-19) such as encephalopathy and seizures have been described. To our knowledge, detailed EEG findings in COVID-19 have not yet been reported. This report adds to the scarce body of evidence. METHODS: We identified eight COVID-19 positive patients who underwent EEG monitoring in our hospital system. RESULTS: EEGs were most commonly ordered for an altered level of consciousness, a nonspecific neurologic manifestation. We observed generalized background slowing in all patients and generalized epileptiform discharges with triphasic morphology in three patients. Focal electrographic seizures were observed in one patient with a history of focal epilepsy and in another patient with no such history. Five of eight patients had a previous diagnosis of epilepsy, suggesting that pre-existing epilepsy can be a potential risk factor for COVID-19-associated neurological manifestations. Five of eight patients who underwent EEG experienced a fatal outcome of infection. CONCLUSIONS: Our findings underscore previous observations that neurologic manifestations are common in severe cases. COVID-19 patients with epilepsy may have an increased risk of neurological manifestations and abnormal EEG.

Barques are generated in posterior hippocampus and phase reverse over lateral posterior hippocampal surface.

OBJECTIVE: To investigate whether barques can be localized across the hippocampal longitudinal axis with sufficient specificity. METHODS: We identified 51 focal epilepsy patients implanted with a minimum of two electrodes - unilateral anterior and posterior - in either hippocampus. We used visual inspection of the intracranial electroencephalogram (iEEG) and 3D brain volume spectrum-based statistical parametric mapping (SPM) to localize barques. RESULTS: In 18/51 patients (35.29%), barques were identified in 22/70 (31.42%) hippocampi. In all hippocampi (100%), barques were present in the posterior hippocampus, while 9 (40.90%) showed concurrent non-independent barque activity anteriorly (P < 0.0001). Statistical parametric mapping confirmed the posterior barque localization, with significant differences in t-values (t(27) = 8.08, P < 0.0001) and z-scores (t(24) = 6.85, P < 0.0001) between anterior and posterior hippocampal barque activity. Posterior lateral extrahippocampal contacts demonstrated phase reversals of positive polarity during barque activity (P = 0.0092, compared to anterior extrahippocampal contacts). CONCLUSIONS: This study highlights the posterior hippocampal predominance of barques. Our findings are concordant with the posterior distribution of the scalp manifestation of barques as "14&6/sec positive spikes". The posterio-lateral hippocampal barque phase reversal can explain the positive polarity of scalp 14&6/sec spikes. SIGNIFICANCE: Understanding the properties of barques is critical for the iEEG interpretation in epilepsy surgery evaluations that include the hippocampus.

Intracranial monitoring contributes to seizure freedom for temporal lobectomy patients with nonconcordant preoperative data.

OBJECTIVE: The question of whether a patient with presumed temporal lobe seizures should proceed directly to temporal lobectomy surgery versus undergo intracranial monitoring arises commonly. We evaluate the effect of intracranial monitoring on seizure outcome in a retrospective cohort of consecutive subjects who specifically underwent an anterior temporal lobectomy (ATL) for refractory temporal lobe epilepsy (TLE). METHODS: We performed a retrospective analysis of 85 patients with focal refractory TLE who underwent ATL following: (a) intracranial monitoring via craniotomy and subdural/depth electrodes (SDE/DE), (b) intracranial monitoring via stereotactic electroencephalography (sEEG), or (c) no intracranial monitoring (direct ATL-dATL). For each subject, the presurgical primary hypothesis for epileptogenic zone localization was characterized as unilateral TLE, unilateral TLE plus (TLE+), or TLE with bilateral/poor lateralization. RESULTS: At one-year and most recent follow-up, Engel Class I and combined I/II outcomes did not differ significantly between the groups. Outcomes were better in the dATL group compared to the intracranial monitoring groups for lesional cases but were similar in nonlesional cases. Those requiring intracranial monitoring for a hypothesis of TLE+had similar outcomes with either intracranial monitoring approach. sEEG was the only approach used in patients with bilateral or poorly lateralized TLE, resulting in 77.8% of patients seizure-free at last follow-up. Importantly, for 85% of patients undergoing SEEG, recommendation for ATL resulted from modifying the primary hypothesis based on iEEG data. SIGNIFICANCE: Our study highlights the value of intracranial monitoring in equalizing seizure outcomes in difficult-to-treat TLE patients undergoing ATL.

Development and Validation of the 5-SENSE Score to Predict Focality of the Seizure-Onset Zone as Assessed by Stereoelectroencephalography.

Importance: Stereoelectroencephalography (SEEG) has become the criterion standard in case of inconclusive noninvasive presurgical epilepsy workup. However, up to 40% of patients are subsequently not offered surgery because the seizure-onset zone is less focal than expected or cannot be identified. Objective: To predict focality of the seizure-onset zone in SEEG, the 5-point 5-SENSE score was developed and validated. Design, Setting, and Participants: This was a monocentric cohort study for score development followed by multicenter validation with patient selection intervals between February 2002 to October 2018 and May 2002 to December 2019. The minimum follow-up period was 1 year. Patients with drug-resistant epilepsy undergoing SEEG at the Montreal Neurological Institute were analyzed to identify a focal seizure-onset zone. Selection criteria were 2 or more seizures in electroencephalography and availability of complete neuropsychological and neuroimaging data sets. For validation, patients from 9 epilepsy centers meeting these criteria were included. Analysis took place between May and July 2021. Main Outcomes and Measures: Based on SEEG, patients were grouped as focal and nonfocal seizure-onset zone. Demographic, clinical, electroencephalography, neuroimaging, and neuropsychology data were analyzed, and a multiple logistic regression model for developing a score to predict SEEG focality was created and validated in an independent sample. Results: A total of 128 patients (57 women [44.5%]; median [range] age, 31 [13-58] years) were analyzed for score development and 207 patients (97 women [46.9%]; median [range] age, 32 [16-70] years) were analyzed for validation. The score comprised the following 5 predictive variables: focal lesion on structural magnetic resonance imaging, absence of bilateral independent spikes in scalp electroencephalography, localizing neuropsychological deficit, strongly localizing semiology, and regional ictal scalp electroencephalography onset. The 5-SENSE score had an optimal mean (SD) probability cutoff for identifying a focal seizure-onset zone of 37.6 (3.5). Area under the curve, specificity, and sensitivity were 0.83, 76.3% (95% CI, 66.7-85.8), and 83.3% (95% CI, 72.30-94.1), respectively. Validation showed 76.0% (95% CI, 67.5-84.0) specificity and 52.3% (95% CI, 43.0-61.5) sensitivity. Conclusions and Relevance: High specificity in score development and validation confirms that the 5-SENSE score predicts patients where SEEG is unlikely to identify a focal seizure-onset zone. It is a simple and useful tool for assisting clinicians to reduce unnecessary invasive diagnostic burden on patients and overutilization of limited health care resources.