Summary
Objective
Defining the roles of heterotopic and normotopic cortex in the epileptogenic networks in patients with nodular heterotopia is challenging. To elucidate this issue, we compared ...heterotopic and normotopic cortex using quantitative signal analysis on stereoelectroencephalography (SEEG) recordings.
Methods
Clinically relevant biomarkers of epileptogenicity during ictal (epileptogenicity index; EI) and interictal recordings (high‐frequency oscillation and spike) were evaluated in 19 patients undergoing SEEG. These biomarkers were then compared between heterotopic cortex and neocortical regions. Seizures were classified as normotopic, heterotopic, or normoheterotopic according to respective values of quantitative analysis (EI ≥0.3).
Results
A total of 1,246 contacts were analyzed: 259 in heterotopic tissue (heterotopic cortex), 873 in neocortex in the same lobe of the lesion (local neocortex), and 114 in neocortex distant from the lesion (distant neocortex). No significant difference in EI values, high‐frequency oscillations, and spike rate was found comparing local neocortex and heterotopic cortex at a patient level, but local neocortex appears more epileptogenic (p < 0.001) than heterotopic cortex analyzing EI values at a seizure level. According to EI values, seizures were mostly normotopic (48.5%) or normoheterotopic (45.5%); only 6% were purely heterotopic. A good long‐term treatment response was obtained in only two patients after thermocoagulation and surgical disconnection.
Significance
This is the first quantitative SEEG study providing insight into the mechanisms generating seizures in nodular heterotopia. We demonstrate that both the heterotopic lesion and particularly the normotopic cortex are involved in the epileptogenic network. This could open new perspectives on multitarget treatments, other than resective surgery, aimed at modifying the epileptic network.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Surgery for spinal cord tumors poses a significant challenge due to the inherent risk of neurological deterioration. Despite being performed at numerous centers, there is an ongoing debate regarding ...the efficacy of pre- and intraoperative neurophysiological investigations in detecting and preventing neurological lesions. This study begins by providing a comprehensive review of the neurophysiological techniques commonly employed in this context. Subsequently, we present findings from a cohort of 67 patients who underwent surgery for intradural tumors. These patients underwent preoperative and intraoperative multimodal somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs), with clinical evaluation conducted three months postoperatively. The study aimed to evaluate the neurophysiological, clinical, and radiological factors associated with neurological outcomes. In univariate analysis, preoperative and intraoperative potential alterations, tumor size, and ependymoma-type histology were linked to the risk of worsening neurological condition. In multivariate analysis, only preoperative and intraoperative neurophysiological abnormalities remained significantly associated with such neurological deterioration. Interestingly, transient alterations in intraoperative MEPs and SSEPs did not pose a risk of neurological deterioration. The machine learning model we utilized demonstrated the possibility of predicting clinical outcome, achieving 84% accuracy.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Focal seizures originating from the temporal lobe are commonly associated with peri‐ictal hypoxemia (PIH). During the course of temporal lobe seizures, epileptic discharges often not only spread ...within various parts of the temporal lobe but also possibly insula and frontal lobe. The link between spatial propagation of the seizure discharges and PIH is still unclear. The present study investigates the involvement of several brain structures including medial temporal structures, temporal pole, anterior insula, and frontal cortex in the occurrence of PIH. Using quantitative indices obtained during SEEG (stereoencephalography) recordings in 38 patients, we evaluated the epileptogenicity, the spatial propagation, and functional connectivity between those structures during seizures leading to PIH. Multivariate statistical analyses of SEEG quantitative indices showed that temporal lobe seizures leading to PIH are characterized by a strong involvement of amygdala and anterior insula during seizure propagation and a more widespread involvement of medial temporal lobe structures, lateral temporal lobe, temporal pole, and anterior cingulate at the end of the seizures. On the contrary, seizure‐onset zone was not associated with PIH occurrence. During seizure propagation, anterior insula, temporal pole, and temporal lateral neocortex activities were correlated with intensity of PIH. Lastly, PIH occurrence was also related to a widespread increase of synchrony between those structures. Those results suggest that PIH occurrence during temporal lobe seizures may be related to the activation of a widespread network of cortical structures, among which amygdala and anterior insula are key nodes.
Focal seizures originating from the temporal lobe are commonly associated with peri‐ictal hypoxemia (PIH). Peri‐ictal hypoxemia is associated with a strong involvement of amygdala and anterior insula during seizure propagation and a more widespread involvement of medial and lateral temporal lobe, temporal pole and frontal lobe at the end of the seizures.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•First study which focus on the association between exposure to ten classes of medicines and the risk of being responsible for a road traffic crash.•Analyses were performed according to the type of ...journey (private, commuting or mission).•Medicines exposure levels were generally lower for drivers during occupational journeys.•Risks were higher on commuting or mission journeys (vs. private journeys) for antiepileptics, psycholeptics, psychoanaleptics and other nervous system drugs.•The implementation of preventive measures about some treatments and diseases in the context of occupational journeys should be developed.
Whereas an increased risk of road traffic crashes has been highlighted as linked to some medicine consumptions, there is no available data on this risk according to the type of journey (private, commuting or mission). Drivers on occupational journey (commuting or mission) are likely to have different coping behaviors related to the use of medicines than drivers on private journey.
The aim of our study was to investigate the association between exposure to ten classes of medicines and the risk of being responsible for a road traffic crash according to the type of journey (private, commuting or mission).
The data used came from three French national databases: the national police database of injurious crashes, the police reports and the national health care insurance database. A total of 179,269 drivers aged between 18 and 65 years old involved in an injurious crash in France between July 2005 and December 2015 were included in the analyses. Logistic regression models stratified by journey were used to estimate the Odds Ratios (OR) and 95 % confidence intervals (95 % CI), adjusted for potential confounding factors.
Medicines exposure levels were generally lower for drivers during occupational journeys, the risk of being responsible for a road traffic crash seems to be higher on commuting or mission journeys than on private journeys for four medicines.
Indeed, for antiepileptics the OR was 1.59 1.01–2.51 for mission journeys, 1.63 1.24–2.15 for commuting journeys, and 1.47 1.25–1.73 for private journey. For psycholeptics the OR was 1.02 0.80–1.28 for mission journey, 1.19 1.03–1.39 for commuting and 1.17 1.08–1.26 for private journey. For psychoanaleptics OR was 1.35 1.02–1.78 for mission journeys, 1.37 1.17–1.60 for commuting journeys and 1.26 1.14–1.40 for private journeys. Finally, for other nervous system drugs OR reached 2.04 1.35–3.07 for mission journeys compared to 1.43 1.21–1.70 for private journeys.
Our results encourage the implementation of preventive measures about some treatments and diseases in the context of occupational journeys.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The incidence of early seizures (occurring within 7 days of stroke onset) after intracerebral haemorrhage reaches 30% when subclinical seizures are diagnosed by continuous EEG. Early seizures might ...be associated with haematoma expansion and worse neurological outcomes. Current guidelines do not recommend prophylactic antiseizure treatment in this setting. We aimed to assess whether prophylactic levetiracetam would reduce the risk of acute seizures in patients with intracerebral haemorrhage.
The double-blind, randomised, placebo-controlled, phase 3 PEACH trial was conducted at three stroke units in France. Patients (aged 18 years or older) who presented with a non-traumatic intracerebral haemorrhage within 24 h after onset were randomly assigned (1:1) to levetiracetam (intravenous 500 mg every 12 h) or matching placebo. Randomisation was done with a web-based system and stratified by centre and National Institutes of Health Stroke Scale (NIHSS) score at baseline. Treatment was continued for 6 weeks. Continuous EEG was started within 24 h after inclusion and recorded over 48 h. The primary endpoint was the occurrence of at least one clinical seizure within 72 h of inclusion or at least one electrographic seizure recorded on continuous EEG, analysed in the modified intention-to-treat population, which comprised all patients who were randomly assigned to treatment and who had a continuous EEG performed. This trial was registered at ClinicalTrials.gov, NCT02631759, and is now closed. Recruitment was prematurely stopped after 48% of the recruitment target was reached due to a low recruitment rate and cessation of funding.
Between June 1, 2017, and April 14, 2020, 50 patients with mild-to-moderate severity intracerebral haemorrhage were included: 24 were assigned to levetiracetam and 26 to placebo. During the first 72 h, a clinical or electrographic seizure was observed in three (16%) of 19 patients in the levetiracetam group versus ten (43%) of 23 patients in the placebo group (odds ratio 0·16, 95% CI 0·03–0·94, p=0·043). All seizures in the first 72 h were electrographic seizures only. No difference in depression or anxiety reporting was observed between the groups at 1 month or 3 months. Depression was recorded in three (13%) patients who received levetiracetam versus four (15%) patients who received placebo, and anxiety was reported for two (8%) patients versus one (4%) patient. The most common treatment-emergent adverse events in the levetiracetam group versus the placebo group were headache (nine 39% vs six 24%), pain (three 13% vs ten 40%), and falls (seven 30% vs four 16%). The most frequent serious adverse events were neurological deterioration due to the intracerebral haemorrhage (one 4% vs four 16%) and severe pneumonia (two 9% vs two 8%). No treatment-related death was reported in either group.
Levetiracetam might be effective in preventing acute seizures in intracerebral haemorrhage. Larger studies are needed to determine whether seizure prophylaxis improves functional outcome in patients with intracerebral haemorrhage.
French Ministry of Health.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Objective
Nodular heterotopias (NHs) are malformations of cortical development associated with drug‐resistant focal epilepsy with frequent poor surgical outcome. The epileptogenic network is complex ...and can involve the nodule, the overlying cortex, or both. Single‐pulse electrical stimulation (SPES) during stereo‐electroencephalography (SEEG) allows the investigation of functional connectivity between the stimulated and responsive cortices by eliciting cortico‐cortical evoked potentials (CCEPs). We used SPES to analyze the NH connectome and its relation to the epileptogenic network organization.
Methods
We retrospectively studied 12 patients with NH who underwent 1 Hz or 0.2 Hz SPES of NH during SEEG. Outbound connectivity (regions where CCEPs were elicited by NH stimulation) and inbound connectivity (regions where stimulation elicited CCEPs in the NH) were searched. SEEG channels were then classified as “heterotopic” (located within the NH), “connected” (located in normotopic cortex and showing connectivity with the NH), and “unconnected.” We used the epileptogenicity index (EI) to quantify implication of channels in the seizure‐onset zone and to classify seizures as heterotopic, normotopic, and normo‐heterotopic.
Results
One hundred thirty‐five outbound and 72 inbound connections were found. Three patients showed connectivity between hippocampus and NH, and seven patients showed strong internodular connectivity. A total of 39 seizures were analyzed: 23 normo‐heterotopic, 12 normotopic, and 4 heterotopic. Logistic regression found that “connected” channels were significantly (p = 8.4e‐05) more likely to be epileptogenic than “unconnected” channels (odds ratio 4.71, 95% confidence interval (CI) 2.17, 10.21) and heterotopic channels were also significantly (p = .024) more epileptogenic than “unconnected” channels (odds ratio 3.29, 95% CI 1.17, 9.23).
Significance
SPES reveals widespread connectivity between NH and normotopic regions. Those connected regions show higher epileptogenicity. SPES might be useful to assess NH epileptogenic network.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract Introduction People with epilepsy may have trouble keeping a job. Certain types of work (working at heights, using machinery, helping dependents, etc.) present risks of accident when the ...seizures occur. Driving restrictions vary in different countries. Medical fitness for work must be assessed on a case-by-case basis, and not according to general standards. With a view to harmonising the practices of occupational physicians, the French Society for Occupational Health has developed recommendations. Method: A taskforce drew up a checklist of parameters to be taken into account in assessing each individual situation. A table was proposed to characterise the risks associated with certain dangerous work situations, with an algorithm to summarise the medical-professional situation. The recommendations were sent to a group of reviewers for their comments. Results The characteristics of epilepsy which make it possible to assess the risk of seizures and the repercussions in the workplace are the syndromic framework, semiological elements of seizures, markers of disease activity, and comorbidities. Favourable factors are also identified. Workplace factors that may favour decompensation from epilepsy include working hours and workload. Occupational situations with a risk of trauma include those involving falls, working at heights, jobs requiring constant vigilance and dangerous machinery. Discussion and Conclusion It is expected that the recommendations will help occupational physicians in assessing individual situations so that people with epilepsy have the best possible chance of keeping their job without risk to their health and persons in their environment.
Predicting the outcome of a comatose or poorly responsive patient is a major issue for intensive care unit teams, in order to give the most accurate information to the family and to choose the best ...therapeutic option. However, determining the level of cortical activity in patients with disorders of consciousness is a real challenge. Reliable criteria are required to help clinicians in the decision-making process, especially in the acute phase of coma. In this paper, we propose recommendations for recording and interpreting electroencephalography and evoked potentials in comatose patients based on the literature and the clinical experience of a group of neurophysiologists trained in the management of comatose patients. We propose methodological guidelines and discuss prognostic value of each test as well as the limitations concerning recording and interpretation. Recommendations for the strategy and timing of neurophysiological assessments are also proposed according to various clinical situations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Stereoelectroencephalography (SEEG) was first developed in the 1950s by Jean Talairach using 2D angiography and a frame-based, orthogonal approach through a metallic grid. Since then, various other ...frame-based and frameless techniques have been described. In this study the authors sought to compare the traditional orthogonal Talairach 2D angiographic approach with a frame-based 3D robotic procedure that included 3D angiographic interoperative imaging guidance. MRI was used for both procedures during surgery, but MRI preplanning was done only in the robotic 3D technique.
All study patients suffered from drug-resistant focal epilepsy and were treated at the same center by the same neurosurgical team. Fifty patients who underwent the 3D robotic procedure were compared to the same number of historical controls who had previously been successfully treated with the Talairach orthogonal procedure. The effectiveness and absolute accuracy, as well as safety, of the two procedures were compared. Moreover, in the 3D robotic group, the reliability of the preoperative MRI to avoid vascular structures was evaluated by studying the rate of trajectory modification following the coregistration of the intraoperative 3D angiographic data onto the preoperative MRI-based trajectory plans.
Effective accuracy (96.5% vs 13.7%) and absolute accuracy (1.15 mm vs 4.00 mm) were significantly higher in the 3D robotic group than in the Talairach orthogonal group. Both procedures showed excellent safety results (no major complications). The rate of electrode modification after 3D angiography was 43.8%, and it was highest for frontal and insular locations.
The frame-based, 3D angiographic, robotic procedure described here provided better accuracy for SEEG implantations than the traditional Talairach approach. This study also highlights the potential safety advantage of trajectory planning using intraoperative frame-based 3D angiography over preoperative MRI alone.
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