Ictal Tachycardia Research Articles

Ictal tachycardia in children with epilepsy

Ictal tachycardia in children with epilepsy

Detection of seizures with ictal tachycardia, using heart rate variability and patient adaptive logistic regression machine learning methods: A hospital-based validation study.

Automated seizure detection of focal epileptic seizures is needed for objective seizure quantification to optimize the treatment of patients with epilepsy. Heart rate variability (HRV)-based seizure detection using patient-adaptive threshold with logistic regression machine learning (LRML) methods has presented promising performance in a study with a Danish patient cohort. The objective of this study was to assess the generalizability of the novel LRML seizure detection algorithm by validating it in a dataset recorded from long-term video-EEG monitoring (LTM) in a Brazilian patient cohort. Ictal and inter-ictal ECG-data epochs recorded during LTM were analyzed retrospectively. Thirty-four patients had 107 seizures (79 focal, 28 generalized tonic-clonic [GTC] including focal-to-bilateral-tonic-clonic seizures) eligible for analysis, with a total of 185.5 h recording. Because HRV-based seizure detection is only suitable in patients with marked ictal autonomic change, patients with >50 beats/min change in heart rate during seizures were selected as responders. The patient-adaptive LRML seizure detection algorithm was applied to all elected ECG data, and results were computed separately for responders and non-responders. The patient-adaptive LRML seizure detection algorithm yielded a sensitivity of 84.8% (95% CI: 75.6-93.9) with a false alarm rate of .25/24 h in the responder group (22 patients, 59 seizures). Twenty-five of the 26 GTC seizures were detected (96.2%), and 25 of the 33 focal seizures without bilateral convulsions were detected (75.8%). The study confirms in a new, independent external dataset the good performance of seizure detection from a previous study and suggests that the method is generalizable. This method seems useful for detecting both generalized and focal epileptic seizures. The algorithm can be embedded in a wearable seizure detection system to alert patients and caregivers of seizures and generate objective seizure counts helping to optimize the treatment of the patients.

De novo ADGRV1 variant in a patient with ictal asystole provides novel clues for increased risk of SUDEP

BackgroundVarious cardiac and autonomic manifestations are frequently reported during seizures. Among the seizure-related arrhythmia, ictal tachycardia is the most common, followed by ictal bradycardia, with ictal asystole being the rarest. The occurrence of ictal asystole may obscure the clinical presentation and delay the diagnosis, representing a life-threatening presentation of epilepsy, with an elevated risk of sudden unexpected death in epilepsy patients (SUDEP). These cardiac abnormalities are being increasingly recognized as the key to elucidating the mechanisms of SUDEP.Case presentationWe present a 35-year-old man with a history of focal-onset seizures with impaired consciousness since his mid-20 s. He developed different types of seizures for 2 years, described as tonic seizure and atonic seizure (drop attack). During such clinical events, he suffered from falls and cardiac arrest. However, thorough cardiac electrophysiology and imaging workup failed to reveal a cardiac etiology. Subsequent video electroencephalograph (EEG) monitoring was performed, and ictal bradycardia and ictal asystole were discovered. A cardiac pacemaker was implanted, and at 3-year follow-up, the patient did not suffer more atonic seizures, or falls. Genetic tests discovered a de novo variant of Adhesion G Protein-Coupled Receptor V1 (ADGRV1), which may provide a clue for the patient’s ictal asystole and the increased risk of SUDEP.ConclusionsConsidering the important impact of ictal bradycardia and asystole on the morbidity and potential mortality of epileptic patients, it is important to simultaneously utilize EEG and electrocardiogram to confirm the diagnosis. This case report highlights the link between the de novo variant of ADGRV1 and the ictal bradycardia/asystole phenotype and implicates the importance of genetic testing in adult epilepsy patients.

Clinical Reasoning: A Young Man With Daily Episodes of Altered Awareness

Stretch syncope is a distinct entity characterized by transient alteration in awareness (TAA) induced by neck hyperextension during stretching. Few cases of stretch syncope have been reported in the literature. Nevertheless, this is a highly relevant diagnosis as it can be easily mistaken for epilepsy for a number of reasons. These include stereotypical motor activity associated with the events, development of ictal tachycardia, and the presence of rhythmic/semirhythmic slowing on EEG in the context of transient cerebral hypoperfusion.We present the case of a young man who was referred to our comprehensive epilepsy center for frequent episodes of TAA. After careful evaluation, the episodes were initially considered to be epileptic. Given that he had negligible clinical response to antiseizure medications, he underwent an experimental protocol at a cardiovascular research laboratory that ultimately confirmed the diagnosis of stretch syncope. The present article describes an approach to the evaluation of TAA and illustrates a typical case of stretch syncope. The importance of considering stretch syncope in the differential diagnosis of TAA is exemplified. Finally, our analyses help elucidate the pathophysiology of this rare entity.

Comparison of traditional and closed loop vagus nerve stimulation for treatment of pediatric drug-resistant epilepsy: A propensity-matched retrospective cohort study

ObjectiveFor epilepsy patients with drug-resistant, unresectable epilepsy, vagus nerve stimulation (VNS) is an option for seizure control. Approximately 40–70% of patients will achieve ≥50% seizure reduction with VNS. New closed loop VNS models detect ictal tachycardia and responsively stimulate the vagus nerve. The effectiveness of closed loop VNS compared to traditional VNS for pediatric epilepsy is unknown. MethodsAn 11-year retrospective electronic medical record review at Children's Hospital of Pittsburgh was performed. Patients with drug-resistant epilepsy who underwent VNS implantation were included. Patients were divided into groups based on VNS model: traditional versus closed loop. Those who transitioned from traditional to closed loop VNS were excluded. Given potential for selection bias, propensity scores matching was utilized to compare traditional to closed loop VNS patients. Patients with focal versus generalized epilepsy were also separately analyzed. The primary outcome was “VNS response”, defined as at least 50% seizure frequency reduction from baseline. ResultsA total of 320 patients were included in this sample. The percentage of matched patients (total n = 220: n = 179 traditional VNS, n = 41 closed loop VNS) who responded to VNS after one year of therapy was 43% for traditional VNS and 39% for closed loop VNS (p = 0.64). After two years of therapy, a higher proportion of closed loop VNS patients than traditional VNS patients responded to VNS among all subgroups, though no differences were statistically significant (p>0.05). Notably, for those with generalized epilepsy, 73% of closed loop patients responded to VNS compared to only 46% of traditional patients (p = 0.10). After two years of VNS therapy, patients were taking approximately the same quantity of antiseizure medications as baseline (change of +0.074 +/- 0.90 ) with no difference between VNS models (p = 0.87). SignificanceAmong pediatric patients with drug-resistant epilepsy, closed loop VNS trends towards a higher rate of VNS response after two years of treatment, especially among generalized epilepsy patients. Neither model of VNS allows patients to reduce antiseizure medication quantity after two years.

Evaluating vagus nerve stimulation treatment with heart rate monitoring in pediatric patients with intractable epilepsy.

Vagus nerve stimulators (VNS) have emerged as an effective treatment modality for pediatric patients suffering from intractable, drug-resistant epilepsy. Newer devices, AspireSR™ Model 106 and the SenTiva™ Model 1000 (VNS TherapyⓇ, LivaNova™), contain an "auto-stimulation" feature that detects ictal tachycardia and transmits pulsations to attenuate seizures. However, the exact benefits of auto-stimulation compared to its risks still merit further exploration. This study evaluates the utility of these specific devices in a heterogeneous population of pediatric and young adult patients with intractable epilepsy. This is a retrospective chart review of 55 patients who underwent either VNS insertion with or without an auto-stimulation-enabled VNS device at a single level four epilepsy center. Seizure frequency, seizure subtype, side effects, and change in anti-seizure medication load both before and after VNS implantations were collected from patient self-reporting at the time of VNS insertion and 12months following implantation. Information regarding output current, auto-stimulation current, duty cycling, and auto-stimulation threshold of the device was obtained from documented VNS interrogation for patients with auto-stimulation-enabled VNS devices. Patients with auto-stimulation-enabled VNS devices had a mean 56.0% (SD = 0.414) seizure frequency reduction 12months post-VNS insertion, while patients without auto-stimulation-enabled VNS devices had a mean 41.6% (SD = 0.456) seizure frequency reduction during the same interval. The mean seizure frequency reduction 12months post-VNS insertion for patients with a SenTiva™ 1000 model was 66.0% (SD = 0.426). For patients with auto-stimulation-enabled VNS devices, post-treatment seizure reduction was significantly correlated with daily auto-stimulation activation (R = 0.432, p = 0.025). This study supports the clinical safety and utility of auto-stimulation-enabled VNS models, specifically the SenTiva™ 1000, in treating pediatric patients with intractable epilepsy of various subtypes and etiologies. Further research is needed to evaluate the sustained impact of auto-stimulation on long-term outcomes (≥ 2years follow-up post-VNS).

Neuromodulation in Intractable Epilepsy Through Responsive Vagal Nerve Stimulation: A Three-Year Retrospective Study at the University of Texas Medical Branch, Galveston.

Background: Vagus nerve stimulation (VNS) functions through neuromodulatory mechanisms to provide quality of life improvements to those with drug-resistant epilepsy. Responsive VNS (rVNS) generators are designed to further reduce seizure burden by detecting ictal tachycardia and aborting seizures soon after their onset. Methods: Electronic medical records were accessed from January 2015 to December 2018 to identify patients with epilepsy managed with rVNS generators. Data were collected on seizure burden before and after rVNS implantation. Seizure burden was compared using t-tests, and monthly seizure reductions were gauged with the McHugh scale. Twenty-seven individuals met inclusion criteria; 10 were eliminated due to prior VNS implantation or undocumented seizure frequencies.Results: The average seizure burden prior to rVNS implantation was 24.78 seizures/month. Following generator placement, the mean seizure frequencies at three months, six months, 12 months, and 18 months were 6.81, 16.57, 5.65, and 5.78 seizures/month, respectively. However, despite documented reductions in the average monthly seizure frequency, we found no statistically significant differences in seizure frequency relative to baseline.Conclusion: While many participants showed individual reductions in seizure burden, this study was unable to definitively conclude that rVNS therapy leads to statistically significant reduction in seizure burden.

Identification of Ictal Tachycardia in Focal Motor- and Non-Motor Seizures by Means of a Wearable PPG Sensor.

Photoplethysmography (PPG) as an additional biosignal for a seizure detector has been underutilized so far, which is possibly due to its susceptibility to motion artifacts. We investigated 62 focal seizures from 28 patients with electrocardiography-based evidence of ictal tachycardia (IT). Seizures were divided into subgroups: those without epileptic movements and those with epileptic movements not affecting and affecting the extremities. PPG-based heart rate (HR) derived from a wrist-worn device was calculated for sections with high signal quality, which were identified using spectral entropy. Overall, IT based on PPG was identified in 37 of 62 (60%) seizures (9/19, 7/8, and 21/35 in the three groups, respectively) and could be found prior to the onset of epileptic movements affecting the extremities in 14/21 seizures. In 30/37 seizures, PPG-based IT was in good temporal agreement (<10 s) with ECG-based IT, with an average delay of 5.0 s relative to EEG onset. In summary, we observed that the identification of IT by means of a wearable PPG sensor is possible not only for non-motor seizures but also in motor seizures, which is due to the early manifestation of IT in a relevant subset of focal seizures. However, both spontaneous and epileptic movements can impair PPG-based seizure detection.

Ictal ECG changes and antiepileptic drug therapy

Abstract Purpose Epileptic seizures may cause severe cardiac arrhythmias. Most people with epilepsy die suddenly and whose death is recognized to a sudden unexpected death in epilepsy (SUDEP). There are controversial reports on the association between polytherapy using antiepileptic drugs and SUDEP. First-line drugs include, in particular, carbamazepine, oxcarbazepine, and lamotrigine, which are sodium channel blockers that may impair heart function. Often a patient requires a combination of antiepileptic drugs Methods 204 patients with epilepsy and were on antiepileptic drugs therapy. The ECG cardiac monitor was implanted in all patients (n=204) and was analyzed together with the preclinical data including age, sex, family history, cardiac risk factors (hypertension, dyslipidemia, diabetes mellitus), heart disease, antiepileptic drug type. Results After a follow-up of 12-month ictal ECG changes (rhythm and conduction disturbances, ST segment abnormalities) were observed in 134 (66%) patients, and only in 70 (34%) – without ictal ECG changes, the average age in these groups was 34,4±9,9 and 36,7±11,8 years (p&amp;gt;0,05). In the group with ictal ECG changes among patients receiving as monotherapy antiepileptic drugs, ictal ECG changes were found in 53.7% of cases, with polytherapy antiepileptic drugs significantly more often – in 71.5% of cases (p&amp;lt;0.05). a reliable association between carbamazepine and changes in sinoatrial and atrioventricular conduction (p=0.01) was significant. In the analyzed group of patients, carbamazepine therapy was also associated with the presence of ictal ST-segment abnormalities (depression/elevation) (p=0.013). A positive association was observed between the administration of oxcarbazepine and development of ictal tachycardia (p=0.04) and ictal right and left bundle branch block, which was observed in 71.4% of cases against the background of oxcarbazepine, significantly more often than with other drugs (p=0.005). Conclusion In agreement with previous publications available in the literature, our results confirm the risk of high-frequency rhythm and conduction disturbances, ST segment abnormalities related to antiepileptic drugs, in particular, carbamazepine and oxcarbazepine and indicates the need of not only cardiological examination before prescribing an antiepileptic drugs, but also a thorough follow-up during the therapy. Patients with ictal ECG changes, primarily rhythm and conduction disturbances, should be under the dynamic control of not only neurologists but also cardiologists and require regular cardiological check-up (ECG, Holter monitoring of the electrocardiogram, echocardiography). Funding Acknowledgement Type of funding source: None

Cardiac arrhythmias and sudden unexpected death in epilepsy: Results of long-term monitoring

Cardiac rhythm and conduction disorders are common in patients with epilepsy and are presumably one of the leading causes of sudden unexpected death. There are only a few published reports on ictal cardiac arrhythmias detected by continuous monitoring, and the majority had a small sample size. The aim of this study was to evaluate the frequency and type of cardiac arrhythmias recorded by an implantable loop recorder in patients with drug-resistant epilepsy. We implanted a subcutaneous loop recorder to 193 patients with drug-resistant epilepsy. Automatic triggers to initiate cardiac rhythm recording were cardiac pauses of >3 seconds and any episodes of bradycardia (≤45 beats/min) or tachycardia (≥150 beats/min). Patients/relatives were instructed to begin peri-ictal rhythm recording by using an external activator device. The follow-up duration was 36 months, with scheduled follow-up visits every 3 months. A total of 6494 electrocardiogram traces were recorded during the median follow-up of 36 months (interquartile range 3-36 months). Ictal heart rhythm and rate changes were detected in 143 patients (74%). The most common finding was ictal sinus tachycardia (66.8%). Sinus bradycardia was observed in 13 patients (6.7%). Three patients had clinically relevant cardiac pauses of >6 seconds, requiring permanent pacemaker implantation. Five patients (2.6%) died suddenly. Ictal heart rhythm and rate changes occur in most of the patients with drug-resistant epilepsy. Clinically relevant cardiac events, related to ictal and postictal periods, are rare. No potentially malignant arrhythmias were detected in patients who died suddenly during the preceding follow-up period.

Vagus nerve stimulation with tachycardia detection provides additional seizure reduction compared to traditional vagus nerve stimulation

PurposeThis study investigates the clinical and cost effectiveness of switching from traditional vagus nerve stimulation (VNS) to responsive VNS (rVNS), which has an additional ictal tachycardia detection and stimulation (AutoStim) mode. MethodsRetrospective chart review was used to collect data from patients with medically refractory epilepsy who underwent generator replacements. Patients with confounding factors such as medication changes were excluded. Vagus nerve stimulation parameters, seizure frequency, and healthcare costs were collected for the 1-year period following generator replacement with the rVNS device. ResultsDocumented seizure frequency was available for twenty-five patients. After implant with rVNS, 28% of patients had an additional ≥50% seizure reduction. There was a significant decrease in the average monthly seizure count (p = 0.039). In patients who were not already free of disabling seizures (n = 17), 41.2% had ≥50% additional seizure reduction. There was no difference in healthcare costs during the 1-year follow-up after the rVNS implant compared with one year prior. ConclusionsIctal tachycardia detection and stimulation provided a significant clinical benefit in patients who were not free of disabling seizures with treatment from traditional VNS. There was no additional increase in healthcare costs during the first year after device replacement.

Investigation of Morphological Variations of Photoplethysmography Signal in Human Epilepsy.

The purpose of this study is to analyse the ictal variations in peripheral blood flow using photoplethysmogram (PPG) and single lead Electrocardiogram (ECG) signals. 11 subjects with 56 partial seizures were recorded with the PPG sensor worn on their left ankles. 6 different features from PPG pulse morphology related to hemodynamics were derived. The seizures were divided into two groups based on the side of the seizure activity. The investigation of ictal variations in features did not show any significant difference between the seizures' lateralizations. The analysis of latencies of ictal changes in the PPG features revealed the PPG pulse amplitude precede the variations in other PPG features including ictal heart rate variability. In addition, analysis of the effect of seizure lengths on ictal variations showed the seizures' lengths have no significant effect on the feature variation rates.Clinical relevance- Analysis of the extracted PPG features and their timing suggest an increase in vascular resistance due to increase in sympathetic tone which occurs prior to the ictal tachycardia. These variations is independent of the seizures' lengths and lateralizations.

Recent Advancement of Technologies and the Transition to New Concepts in Epilepsy Surgery.

Fruitful progress and change have been accomplished in epilepsy surgery as science and technology advance. Stereotactic electroencephalography (SEEG) was originally developed by Talairach and Bancaud at Hôspital Sainte-Anne in the middle of the 20th century. SEEG has survived, and is now being recognized once again, especially with the development of neurosurgical robots. Many epilepsy centers have already replaced invasive monitoring with subdural electrodes (SDEs) by SEEG with depth electrodes worldwide. SEEG has advantages in terms of complication rates as shown in the previous reports. However, it would be more indispensable to demonstrate how much SEEG has contributed to improving seizure outcomes in epilepsy surgery. Vagus nerve stimulation (VNS) has been an only implantable device since 1990s, and has obtained the autostimulation mode which responds to ictal tachycardia. In addition to VNS, responsive neurostimulator (RNS) joined in the options of palliative treatment for medically refractory epilepsy. RNS is winning popularity in the United States because the device has abilities of both neurostimulation and recording of ambulatory electrocorticography (ECoG). Deep brain stimulation (DBS) has also attained approval as an adjunctive therapy in Europe and the United States. Ablative procedures such as SEEG-guided radiofrequency thermocoagulation (RF-TC) and laser interstitial thermal therapy (LITT) have been developed as less invasive options in epilepsy surgery. There will be more alternatives and tools in this field than ever before. Consequently, we will need to define benefits, indications, and limitations of these new technologies and concepts while adjusting ourselves to a period of fundamental transition in our foreseeable future.

Sensor Based Pre-Detection of TLE (Temporal Lobe Epilepsy)

1.Funtional Hb(carries oxygens) ->OXYHAEMOGLOBIN 2.Non Functional Hb(don’t carry oxygen)->Carboxy and MethHb Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through. Deoxygenated (or reduced) hemoglobin absorbs more red light and allows more infrared light to pass through. HbO2-> IR(910nm) Hb->Red Light(660 nm) The project aims at reducing the percentage of people suffering from Epileptic Seizures and dying as a result of SUDEP (Sudden Unexpected death in Epilepsy)by pre-detecting seizure attack at it’s initial stage and thereby making immediate medical care possible. The cost have been minimized in order to make it affordable for all economic groups. The compactness provides easy handling of the device. It inflicts no harm to the environment and the body of the subject concerned. As per the report published by Atlas Epilepsy Care on 2005, Epilepsy is affecting life of more than 50 million people worldwide. 80% of the burden of epilepsy is in the developing world, where in some areas 80–90% of people with epilepsy receive no treatment at all. With continuous expansion of health care market in both developing and developed countries, as per 2017 report Epilepsy Drug market has already reached over 9.5 Billion USD and continue to show exceptional growth.By looking at this stat, this low cost device will create a huge impact to the society and will encourage investor to invest on the product. Most foreseeing revenue will be generated from the Developing countries like India and the estimated revenue impact can only be justified once a working model development is completed. • For some people living with epilepsy, the risk of Sudden Unexpected Death in Epilepsy (SUDEP) is an important concern. SUDEP refers to deaths in people with epilepsy that are not caused by injury, drowning, or other known causes. The exact cause is not known, but these are most possible factors: 1. Breathing 2. Heart rhythm. Complex partial seizures originated from both left and right temporal lobes. Mean seizure duration (+/-SD) was 73 +/- 18 s .Mean Spo2 was 83 +/- 5% (range, 77-91%), occurring an average of 35 +/- 12 s after the onset of the desaturation. Of the 181 seizures from 81 patients with ictal ECGs, 177 seizures (98%) from 77 patients were accompanied by ictal tachycardia(above 100 beats per minute). And only 1 patient was accompanied by ictal bradycardia. HR increases rapidly within 10 seconds before seizure onset and ictus, and typically slows to normal with seizure offset. Common carotid arteries chiefly supply the head and neck region. Each common carotid artery bifurcates into external carotid artery(ECA) and internal carotid artery (ICA).There are two types of Haemoglobin consisted in the blood.

Effect of Intractable Epilepsy on the Physiological Cardiac Performance Parameters and the Serum Levels of Cardiac Fatty Acid Binding Protein in Pediatrics

AbstractBackground: Multiple cardiac changes and various abnor-malities have been linked to epileptic fits. The assessment of cardiac changes and serum biomarkers level are commonly accepted methods to evaluate autonomic disturbances during epileptic fits which is very closely associated with some cardiovascular events especially the sudden unexpected cardiac death.Aim of Study: To evaluate ictal and inter-ictal cardiac changes and plasma levels of heart type fatty acid binding protein (H-FABP) in pediatric patients with treatment resistant epilepsy.Patients and Methods: 32 seizure attacks were recorded in 23 children with intractable seizures. Simultaneous Holter-ECG and video-EEG recordings were done with evaluation of changes in Heart Rate (HR), parameters of Heart Rate Variability (HRV), as well as serum levels of H-FABP as a marker of myocardial ischemia in the ictal and inter-ictal periods and compared with a control group.Results: The recorded HR changes included Ictal Tachy-cardia (IT) (96.87%), Ictal Bradycardia (IB) (3.13%), Prema-ture Atrial Contractions (PAC) (18.75%) and Premature Ventricular Contractions (PVC) (28.13%) in the first post-ictal hour. Significant HR increase was observed in the pre-ictal hour and ictal values compared to basal values and remained high 2 hours post-ictally. Basal HR and serum levels of the H-FABP protein were significantly higher while time domain HRV parameters were significantly lower in the patients compared to controls.Conclusion: Significant cardiac changes may occur even before the seizure onset in cases with intractable epilepsy. The increased levels of H-FABP may indicate the presence of autonomic instability and myocardial ischemia even in asymptomatic patients.

F02. Tachycardia-triggered vagus nerve autostimulation using the AspireSR 106 model in patients with refractory epilepsy: Treatment outcome between de novo implantation and replacement of old models

Vagus nerve stimulation (VNS) therapy with open-loop stimulation has been shown to effectively reduce the frequency or severity of seizures. Manual application of the magnet to trigger extrastimulation at the time of the perceived seizure onset may not be feasible in some patients. The automatic stimulation mode (AutoStim, closed-loop) feature of AspireSR 106 model, triggered by ictal tachycardia (IT), aims to terminate a seizure or to reduce severity. We presented a novel series to further refine the benefit of AutoStim. We retrospectively analyzed seizure frequency, severity, and clinical outcome in 24 adult patients with AspireSR 106 implanted between 8/2015 and 7/2017; 13 were replacements of old models, and 11 de novo implantation. Pre-implantation: all patients failed more than 2 antiepileptics, with more than 3 seizures each month. No severe post-implantation adverse events were reported. 13 patients (5 M/8F, median age 32, mean followup 13.6 months) underwent replacement of old models. Malfunctional VNS were found in 6 patients, only two patients reported less frequent seizures. Near end of service or low battery was reported in 7 patients, none reported changes in seizure frequency, but one patient noted reduced severity. 11 patients (4 M/7F, median age 40, mean followup 8.7 months) were de novo implantation. Prior to implantation, 9 patients were monitored in EMU, of whom 4 were found with IT (identified as 50% HR increases from pre-ictal baseline). IT detected by AspireSR 106 at seizure onset was confirmed by EEG monitoring in one patient post-implantation. While followup, time-stamp data were retrieved in 3 patients and showed 60–70% match rate between IT detection and the reported seizures. Average seizure reduction was 37 ± 11% in all 11 patients. Within this group, 8 patients (4 with IT) reported good seizure control, of whom 5 patients had over 50% reduction in frequency and notable decreases of severity, 3 patients reported dramatic decreases of severity with 13.9% reduction in frequency. One patient elected to turn off AutoStim for 2 months, increased aura frequency was noted during the AutoStim OFF period. The frequency was dramatically decreased after AutoStim was resumed. One patient elected not to turn on the AutoStim feature for 6 months after the implantation. The seizure frequency was reduced ∼40% during the open loop stimulation period. It produced a further 70% reduction in frequency and significantly decreased severity with AutoStim turned on. Our data have suggested that, with pre-implantation monitoring and identification of IT, the combined open- and closed-loop stimulation delivered by AspireSR 106 may exhibit greater efficacy in seizure control. The AutoStim has an acceptable specificity of triggering VNS at seizure onset. The discrepancy between the replacement and de novo group raises the question about best utilization, which should prompt larger studies to confirm the clinical efficacy of AutoStim in different groups.

T58. Automatic seizure detection based on multimodal signal quantification

Introduction Quantitative analysis and automated seizure detection is able to increase efficiency of EEG review. However, acceptance of software assisted review is often low because results are inaccurate in real world patient cohorts and the reason for false detections cannot be deduced. The graphical software tool encevis visualizes detections of fast rhythmic activity and patterns defined by the ACNS critical care EEG terminology. Based on these detections as well as quantitative information of EEG, ECG, and EMG a multimodal seizure detection algorithm was developed. Simple rule based classification is utilized that facilitates easy interpretability. Aim of this work was to assess detection performance of different modalities and patient groups. Methods Our computer algorithm automatically detects seizures including rhythmic EEG patterns that show an increased amplitude compared to baseline. EMG signal is extracted by bandpass filtering EEG (30–60 Hz) to measure line length (LL) for detection of sustained and excessive ictal EMG activity of generalized tonic-clonic seizures (GTCS). High absolute values of LL and an increase of 500% to baseline trigger detections. Heart rate is calculated from ECG signals to detect ictal tachycardia (ITC) with more than 100 beats per minute and an increase of over 30% compared to baseline. To assess sensitivity and false detection rate a retrospective study was conducted including EEG/ECG recordings of 92 patients from two epilepsy monitoring units. Inclusion criteria were an age above 18 and at least one recorded epileptic seizure. EEGs were used without modification or manual editing of any kind. Automatic seizure detection was calculated for all 11,978 h of EEG (min = 23 h, max = 547 h). In total 410 manual seizure annotations were compared to automatic detections to define sensitivity (SE) and false detection in 24 h (FD/24 h). Results Combination of all three seizure detection methods (EMG + ECG + EEG) resulted in SE = 88% with 10.5 FD/24 h on average. By using only EMG based detections 100% of GTCS (n = 49) were found with an average false detection rate of 3.39 FD/24 h. Seizure detection solely based on ECG yielded SE = 31% with 1.35 FD/24 h. Analysis of the temporal lobe epilepsy patients showed SE = 93.3% and 6.75 FD/24 h, the extra temporal lobe patient group resulted in SE = 80% at 15.3 FD/24 h. Conclusion We showed that automatic seizure detection based on multimodal signal quantification can reach high sensitivity. The low false detection rate results in an average of 20 false detections per week than can be validated quickly by using EEG and time synchronized quantitative screens in parallel. By visualizing quantitative information that is the source of automatic seizure detection the interpretability of results is improved. Our proposed approach to automatic EEG analysis will raise efficiency of post hoc analysis compared to the current state of the art.

Platform Session – Electroencephalography/Epilepsy: The neural bases of ictal tachycardia in temporal lobe seizures

Due to limited information from scalp electroencephalographic (EEG) recordings, brain areas driving changes in cardiac rhythm during Temporal lobe (TL) seizures are not clearly identified. Using stereotactic EEG (SEEG) recordings, we aimed at identifying which of the brain regions involved in autonomic control trigger ictal tachycardia. The neural activity of several mesial temporal lobe structures including amygdala, hippocampus, insula, and lateral temporal lobe recorded with SEEG were collected during 37 TL seizures in 9 patients, using indices based on High Frequency Activity (HFA). R-R intervals (RR) monitoring and time-frequency spectral analysis were performed to assess parasympathetic (High frequency power (HF)) and sympathetic (Low frequency/High frequency (LF/HF) ratio) reactivities. Tachycardia was associated with a significant increase in LF/HF ratio and decrease in HF. Autonomic cardiac changes were accompanied by simultaneous SEEG signal changes with an increase in seizure-related HFA in anterior hippocampal formation and amygdala, but not in insula. In our sample, TL seizures are thus accompanied by an early decrease in parasympathetic control of cardiac rhythm and by an increase of sympathetic tone, concomitant to seizure activity in anterior hippocampus and amygdala. These results support a pivotal role of hippocampus and amygdala in tachycardia occurring during TL seizures.

S03. Ictal asystole - A rare presentation of focal epilepsy

Introduction Ictal tachycardia has been frequently observed during temporal lobe seizures. However, Ictal severe bradycardia and asystole are less common and can be associated with serious consequences including risk of sudden death. We present a case of ictal syncope in a woman with recurrent episodes of loss of consciousness and fall. Methods A 69 year old right handed woman presented with one year history of recurrent episodes of loss of consciousness. The patient experienced a number of events when she suddenly develops a funny feeling in her head associated with visual disturbances and followed by loss of awareness and fall. She describes a quick recovery and return to baseline after these episodes. She also reported episodes of rising sensation in her stomach followed by loss of awareness and fall. She denied any prior history of convulsive seizures. She was treated with levetiracetam but continued to experience these episodes. Her brain MRI showed left inferior frontal cavernous angioma that has been seen on previous brain imaging. The patient was admitted to our epilepsy monitoring unit for evaluation of her recurrent spells. Her seizure medication was gradually withdrawn to capture typical events. Her interictal EEG showed bilateral independent temporal slowing and rhythmic delta activity (TIRDA). Results Video EEG evaluation was obtained at our epilepsy monitoring unit. The patient experienced multiple epileptic seizures emanating from the right temporal region and associated with significant bradycardia as well asystole that lasted up to 20 s. Her EEG demonstrated rhythmic right temporal slowing at the onset of her events concurrently associated with bradycardia. This was followed by diffuse severe suppression of background consistent with syncope that correlated with asystole on her EKG. She experienced one seizure that had an onset of right temporal theta seizure discharge and bradycardia and later appeared to have left hemifacial contraction, and then left upper extremity dystonic posturing, before generalization of her seizure. Her case was discussed with our cardiac electrophysiology consult team and she was transferred to the cardiac care unit for pacemaker implantation. Conclusion This case describes an uncommon presentation of recurrent syncope due to temporal lobe seizures that are associated with severe bradycardia and prolonged asystole.

Potentially high-risk cardiac arrhythmias with focal to bilateral tonic-clonic seizures and generalized tonic-clonic seizures are associated with the duration of periictal hypoxemia.

To investigate potentially high-risk cardiac arrhythmias (PHAs) following focal to bilateral tonic-clonic seizures (FBTCSs) and generalized tonic-clonic seizures (GTCSs) and to study the association of PHAs with seizure characteristics and the severity of associated ictal respiratory dysfunction. Electrocardiographic (EKG) and pulse oximetry (SpO2 ) data were recorded concurrently with video-electroencephalographic telemetry in the epilepsy monitoring unit (EMU). One minute of preictal EKG, the ictal EKG, and 2min of ictal/postictal data were reviewed for each seizure. Nonsustained ventricular tachycardia, bradyarrhythmia, and/or sinus pauses were considered as PHAs. FBTCSs/GTCSs with PHAs were compared to those that had only ictal sinus tachycardia. Data from 69 patients with 182 FBTCSs/GTCSs with usable SpO2 and EKG recordings were available. There were 10 FBTCSs/GTCSs in 10 patients with a PHA. The presence of PHAs was not associated with seizure duration or SpO2 nadir. FBTCSs/GTCSs with a PHA were significantly associated with the duration of oxygen desaturation < 90% when compared with FBTCSs/GTCSs with only sinus tachycardia (Mann-Whitney, p=0.042). Desaturation duration of <100s was not significantly associated with occurrence of PHAs (p=0.110) when compared with seizures that had only sinus tachycardia. The odds ratio for occurrence of PHA was 7.86 for desaturation durations ≥ 125s versus desaturations < 125s (p=0.005). The odds ratio increased to 13.09 for desaturation durations ≥ 150s (p<0.001). Preictal and ictal/postictal arrhythmias occurred with focal seizures that did not progress to FBTCSs. Four patients with focal seizures had ictal/postictal PHAs without preictal PHAs. Two of these patients had evidence for prior cardiac disturbance. PHAs following a single FBTCS/GTCS in the EMU are significantly associated with the duration of ictal/postictal hypoxemia. It is possible that FBTCS/GTCS-associated hypoxemia may trigger fatal cardiac arrhythmias in a subset of susceptible patients dying of sudden unexpected death in epilepsy.