Summary: Purpose: Cardiac asystole provoked by epileptic seizures is a rare but important complication in epilepsy and is supposed to be relevant to the pathogenesis of sudden unexplained death in epilepsy (SUDEP). We sought to determine the frequency of this complication in a population of patients with medically intractable epilepsy and to analyze the correlation between EEG, electrocardiogram (ECG), and clinical features obtained from long‐term video‐EEG monitoring.Methods: Retrospective analysis of the clinical records of hospitalized patients from May 1992 to June 2001 who underwent long‐term video‐/EEG monitoring.Results: Of a total of 1,244 patients, five patients had cardiac asystole in the course of ictal events. In these patients, 11 asystolic events, between 4 and 60 s long in a total of 19 seizures, were registered. All seizures had a focal origin with simple partial seizures (n = 13), complex partial seizures (n = 4), and secondarily generalized seizures (n = 2). One patient showed the longest asystole ever reported (60 s) because of a seizure. Cardiac asystole occurred in two patients with left‐sided temporal lobe epilepsy (TLE) and in three patients with frontal lobe epilepsy (FLE; two left‐sided, one bifrontal). Two patients reported previous cardiac disease, but only one had a pathologic ECG by the time of admission. Two patients had a simultaneous central ictal apnea during the asystole. None of the patients had ongoing deficits due to the asystole.Conclusions: These findings confirm that seizure‐induced asystole is a rare complication. The event appeared only in focal epilepsies (frontal and temporal) with a lateralization to the left side. A newly diagnosed or known cardiac disorder could be a risk factor for ictal asystole. Abnormally long postictal periods with altered consciousness might point to reduced cerebral perfusion during the event because of ictal asystole. Central ictal apnea could be a frequent associated phenomenon.
In patients with pharmaco-resistant focal epilepsies investigated with intracranial electroencephalography (iEEG), direct electrical stimulations of a cortical region induce cortico-cortical evoked potentials (CCEP) in distant cerebral cortex, which properties can be used to infer large scale brain connectivity. In 2013, we proposed a new probabilistic functional tractography methodology to study human brain connectivity. We have now been revisiting this method in the F-TRACT project (f-tract.eu) by developing a large multicenter CCEP database of several thousand stimulation runs performed in several hundred patients, and associated processing tools to create a probabilistic atlas of human cortico-cortical connections. Here, we wish to present a snapshot of the methods and data of F-TRACT using a pool of 213 epilepsy patients, all studied by stereo-encephalography with intracerebral depth electrodes. The CCEPs were processed using an automated pipeline with the following consecutive steps: detection of each stimulation run from stimulation artifacts in raw intracranial EEG (iEEG) files, bad channels detection with a machine learning approach, model-based stimulation artifact correction, robust averaging over stimulation pulses. Effective connectivity between the stimulated and recording areas is then inferred from the properties of the first CCEP component, i.e. onset and peak latency, amplitude, duration and integral of the significant part. Finally, group statistics of CCEP features are implemented for each brain parcel explored by iEEG electrodes. The localization (coordinates, white/gray matter relative positioning) of electrode contacts were obtained from imaging data (anatomical MRI or CT scans before and after electrodes implantation). The iEEG contacts were repositioned in different brain parcellations from the segmentation of patients' anatomical MRI or from templates in the MNI coordinate system. The F-TRACT database using the first pool of 213 patients provided connectivity probability values for 95% of possible intrahemispheric and 56% of interhemispheric connections and CCEP features for 78% of intrahemisheric and 14% of interhemispheric connections. In this report, we show some examples of anatomo-functional connectivity matrices, and associated directional maps. We also indicate how CCEP features, especially latencies, are related to spatial distances, and allow estimating the velocity distribution of neuronal signals at a large scale. Finally, we describe the impact on the estimated connectivity of the stimulation charge and of the contact localization according to the white or gray matter. The most relevant maps for the scientific community are available for download on f-tract. eu (David et al., 2017) and will be regularly updated during the following months with the addition of more data in the F-TRACT database. This will provide an unprecedented knowledge on the dynamical properties of large fiber tracts in human.
Background: Following stroke, acute symptomatic seizures (manifestation within seven days) and epilepsy, i.e. occurrence of at least one unprovoked seizure (manifestation after more than seven days), are reported in 3-6% and up to 12% of patients, respectively. Incidence of acute symptomatic seizures is higher in intracranial haemorrhage (10-16%) than in ischaemic stroke (2-4%). Acute symptomatic seizures and unprovoked seizure may be associated with unfavourable functional outcome and increased mortality. In view of the clinical relevance, the European Stroke Organisation has issued evidence-based guidelines on the management of post-stroke seizures and epilepsy. Method: A writing committee of six clinicians and researchers from five European countries and Israel identified seven questions relating to prevention of (further) post-stroke seizures and epilepsy and to amelioration of functional outcome and prevention of mortality. Recommendations are based on findings in randomised controlled trials and observational studies using the grading of recommendations assessment, development and evaluation approach. Results: In the absence of adequately powered randomised controlled trials, evidence for all recommendations is very low. Based on findings in observational studies, some weak recommendations have been made. In most instances, we suggest not to administer antiepileptic drugs. Due to high incidence of seizure recurrence after one post-stroke unprovoked seizure, secondary antiepileptic drugs prophylaxis needs to be considered. Conclusion: Due to very low evidence, these guidelines only give some weak recommendations on prevention of occurrence and recurrence of post-stroke acute symptomatic seizures and unprovoked seizure. Adequately powered randomised controlled trials are required to assess interventions for post-stroke seizure management.
Aims. The COVID‐19 pandemic shook European healthcare systems, with unavoidable gaps in the management of patients with chronic diseases. We describe the impact of the pandemic on epilepsy care in three tertiary epilepsy centres from Spain and Italy, the most affected European countries. Methods. The three epilepsy centres, members of the European EpiCARE network, manage more than 5,700 people with epilepsy. In Bologna and Barcelona, the hospitals housing the epilepsy centres were fully converted into COVID‐19 units. We describe the reorganization of the clinics and report on the frequency of SARS‐CoV‐2 in people with epilepsy as well as the frequency of seizures in patients admitted to the COVID units. Finally, we elaborate on critical issues regarding the second phase of the pandemic. Results. The activities related to epilepsy care were reduced to less than 10% and were deprioritized. Discharges were expedited and elective epilepsy surgeries, including vagal nerve stimulator implantations, cancelled. Hospitalizations and EEG examinations were limited to emergencies. The outpatient visits for new patients were postponed, and follow‐up visits mostly managed by telehealth. Antiseizure medication weaning plans and changes in vagal nerve stimulator settings were halted. Among the 5,700 people with epilepsy managed in our centres, only 14 tested positive for SARS‐CoV‐2, without obvious impact on their epilepsy. None of the 2,122 patients admitted to COVID units experienced seizures among the early symptoms. Conclusion. Epilepsy care was negatively impacted by the pandemic, irrespective of COVID‐19 epidemiology or conversion of the hospital into a COVID‐19 centre. The pandemic did not silence the needs of people with epilepsy, and this must be considered in the planning of the second phase.
Theoretical models of episodic memory have proposed that retrieval depends on interactions between the hippocampus and neocortex, where hippocampal reinstatement of item-context associations drives neocortical reinstatement of item information. Here, we simultaneously recorded intracranial EEG from hippocampus and lateral temporal cortex (LTC) of epilepsy patients who performed a virtual reality spatial navigation task. We extracted stimulus-specific representations of both item and item-context associations from the time-frequency patterns of activity in hippocampus and LTC. Our results revealed a double dissociation of representational reinstatement across time and space: an early reinstatement of item-context associations in hippocampus preceded a later reinstatement of item information in LTC. Importantly, reinstatement levels in hippocampus and LTC were correlated across trials, and the quality of LTC reinstatement was predicted by the magnitude of phase synchronization between hippocampus and LTC. These findings confirm that episodic memory retrieval in humans relies on coordinated representational interactions within a hippocampal-neocortical network.
Our series describes a so far not well-recognized autoimmune association of pilomotor seizures to limbic encephalitis. This etiology should be ruled out through a comprehensive diagnostic work-up even in cases of long-lasting TLE with typical hippocampal atrophy on MRI.
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