iec-2024-eposter-folge-quer-66b4a9fa62f4c635233962.jpg

iec-2024-logo-fussleiste-66b4ac0ccc211506337853.svg

iec-2024-eposter-start-quers2-66b4b6a87c61b926135577.jpg

16th International Epilepsy Colloqium

Associate Professor

Prof. Dr.

Dr. med.

Prof. Dr. med.

Univ.-Prof. Dr. med.

PD Dr.

Long-term effects of epicranial focal cortex stimulation with the EASEE system in pharmacoresistant focal epilepsy

Treatment of drug refractory epilepsy

IntroductionOne third of patients with focal epilepsy are pharmacoresistant, and only some of them are good candidates for epilepsy surgery. Stimulation of the epileptic focus has been reported to effectively reduce seizure frequency using a new epicranially implanted device (EASEE). So far data have been published for a treatment period of 6 months (Schulze-Bonhage et al., JAMA Neurol 2023, 80:588-596). We here for the first time report long-term treatment efficacy over a period of 24 months of this new treatment approach based on the pooled-analysis of two prospective, multicenter, single-arm trials with the implantable EASEE System (EASEE II and PIMIDES I).ObjectivesTo analyze long-term efficacy of epicranial focal cortex stimulation, we here report long-term treatment efficacy over a period of 24 months of this new treatment approach based on the pooled-analysis of two prospective, multicenter, single-arm trials with the implantable EASEE System (EASEE II and PIMIDES I).Materials ane MethodsIn both trials, a total of 33 patients (18 male, 15 female, age 18-75 y, mean age 34.6 y) from seven epilepsy centers in Germany and Belgium were implanted with a neurostimulation system consisting of a pulse generator and a 5-channel electrode array. The system delivers FCS via the stimulation electrode implanted epicranially above the individual epileptic focus region. Outcome data from unblinded stimulation were analyzed based on seizure diaries over a follow-up period of 2 years regarding monthly responder rate (RR: ≥ 50% seizure frequency reduction), monthly seizure frequency (SF), and safety.Results81% of patients initially stimulated choose to continue epicranial focus stimulation for a period of 2 years. The responder rate was 41.4 % (95% CI, 23.5%-61.1%; n=29) at 1 year follow-up and 65.4 % at 2 years follow-up (95% CI, 44.3%-82.8%; n=26).The median monthly seizure frequency decreased from a median baseline of 12/month, to 8/month at 1 year and to 5/month at 1.5 and 2 years follow-up, corresponding to a median seizure frequency reduction by 33% at 12 months follow-up (n=29), and 68% after 18 and 24 months follow-up (n=26).There were no serious adverse events considered related to the neurostimulation procedure also during the prolonged stimulation period.ConclusionsLong-term outcomes suggest that epicranial electrical stimulation of the epileptic focus using the EASEE System is a new treatment approach with pharmacoresistant focal epilepsy with maintained efficacy and excellent tolerability also over a two-year-period.

Poster

PD Dr. med.

Chances and limitations of point of care EEG in the assessment of children with unclear altered mental status in the emergency department

Pediatric epilepsy

Introduction: Rapid diagnosis and treatment are essential in children with altered mental status (ASM). The most important neurological causes are encephalitis and non-convulsive status epilepticus (NCSE). The EEG is an essential part of the diagnosis. A standard EEG (sEEG) poses logistical problems and is time-consuming. A point of care EEG with two channels (poc-EEG) is easy to install in the emergency department, but there is little literature on its feasibility and benefits. We present the preliminary results of a retrospective and prospective study.Aim: To test the feasibility and utility of poc-EEG in differentiating NCSE from other causes in children with ASM in the emergency department.Patients and methods: We recruit all children presenting to the emergency department with unclear ASM. We document the symptoms, the time interval between arrival in the emergency department and installation of the poc-EEG, the bedside poc-EEG findings in the emergency department, the poc-EEG findings by the neuropediatrician on duty on the phone, additional diagnostics performed and the final diagnosis. Case examples are presented.Results: So far, 30 children have been recruited (20 retrospectively and 10 prospectively). The pocEEG could be installed in 14/30 within a maximum of 20 minutes. The pocEEG was unremarkable in 11/30 cases; 17/30 showed rhythmic spike waves and 2/30 showed focal changes. The final diagnoses were: postictal state (n=7), NCSE (n=17), shunt dysfunction (n=1), encephalitis (n=1), psychogenic (n=1), disturbance of consciousness in hypoglycemia (n=1) and unclear (DD psychogenic, DD confusional migraine) (n=2). In the prospective part (n=10), the emergency physician found the pocEEG helpful for diagnosis and therapy in 9/10 of the cases. The poc-EEG findings of the emergency physician and the neuropaediatrician agreed in 6/10 of the cases.Conclusion: The pocEEG can be installed quickly and easily. It can help to detect NCSE in children with an unclear ASM and indirectly indicate the presence of encephalitis.

Prof.

Introducing the Concept of Error Vectors to Improve Source Localization of Epileptic Discharges

Epilepsy surgery

Objective: To optimal estimate, the source location of epileptic discharges (ED) by improving the source localization of ED recorded on simultaneous stereo-EEG/scalp EEG.Methods: Localization error of electrical source imaging (ESI) was evaluated in comparison to known sources of stimulation potentials (SP) by recording simultaneous stereo-EEG and 37-electrode scalp EEG. Error vectors were defined as the directed offset of the ESI-dipole of the SP to the stereo-EEG contacts used for stimulation. Error vectors were applied reversely to the ESI-dipole of interictal ED (IED-dipole).Results: Seven interictal ED (IED) populations (5 temporal from non-lesional patients, 2 prefrontal from patients with suspected FCD) were evaluated (the latter, ictal ED were recorded at the same stereo-EEG contacts). Corrected IED-dipoles were located closer to IED onset contacts on stereo-EEG than uncorrected IED-dipoles (median (IQR): 7.8(2.5) vs 18.7(10.7) mm, P=0.02). For high skull conductivities (skull: skin conductivity ratio of 1:8 &amp; 1:16), all corrected IED-dipoles were located partly in cortex and/or adjacent to focal cortical dysplasia whereas uncorrected dip-ED were located in white matter or CSF (P=0.03). The cortical extent of IED generators, which estimated from corrected IED-dipole was 16.5 (IQR 10.4) cm2. The relationship of stereo-EEG IED amplitude (a) drop with increasing distance (d) from corrected IED-dipole could be modeled as a negative power equation a(d)∝ 1/db (R2=0.87, P&lt;0.01), b ranging from -0.79 to -2.3, median:-1.57.Conclusions: Application of error vectors moves the ESI-dipole of ED to an anatomically and physiologically plausible location.

Impact of VNS Placement on Seizure-Related Emergency Department Visits at 1, 2, and 3 Years Post-Implantation

Introduction: Drug-resistant epilepsy, characterized by the failure of two or more appropriate anti-epileptic medications to achieve seizure freedom, poses significant treatment challenges. Among the neuro-modulating devices used in current epilepsy treatments, vagal nerve stimulation (VNS) is thought to affect cortical activity via projections from the nucleus tractus solitarius to other brainstem nuclei and the cortex. VNS has been FDA-approved since 1997.Objective: This study aims to analyze the impact of VNS implantation on the frequency of seizure-related emergency department (ED) visits at 1, 2, and 3 years post-implantation.Materials &amp; Methods: A single-center retrospective analysis was conducted on patient charts diagnosed with epilepsy and implanted with a VNS device between 2010 and 2023. Of the 128 charts reviewed, 70 were excluded due to missing data, lack of follow-up, or concurrent treatments such as temporal lobectomy. The final analysis included 58 patients. The study compared the number of ED visits one year pre-implantation to those at one, two, and three years post-implantation using the Wilcoxon signed-rank test (p&lt;0.05). Descriptive analyses of quantitative and categorical data were also performed.Results: The average age of epilepsy onset was 16.5 ± 12.4 years, with females constituting 50% of the patient population. The median age at VNS implantation was 36 ± 12.2 years, and the median number of medications at implantation was three. Generalized onset seizures were observed in 41% of patients, focal onset in 22.4%, and both in 6.9%. No significant difference in ED visits was noted between one year pre-implantation and the first year post-implantation (p=0.24) or the second year post-implantation (p=0.06). However, a significant reduction in ED visits was observed in the third year post-implantation compared to baseline (p=0.049). Of the patients, 39 had no ED visits in the year prior to VNS implantation, and most continued to have no ED visits in the subsequent year. Among the 11 patients with at least two ED visits in the year before VNS, most experienced an improvement post-implantation.Conclusion: While no statistical difference in ED visits was observed at one and two years post-VNS implantation, a significant decrease was noted at three years. Patients with two or more ED visits prior to implantation showed significant reductions in ED visits one year post-implantation. The absence of ED visits in a subset of patients raises questions about potential data voids due to follow-ups in other health systems.The study faced limitations due to a lack of documentation on patients seeking care in other health systems and a high loss to follow-up, reducing the study's power. Future research should consider factors such as VNS parameters, age of epilepsy onset, and long-term follow-up data, especially after the introduction of the auto-stimulation function in VNS devices.

Lecture hall 1

Poster session

Short presentations – Stimulation

Poster session
Short presentations – Stimulation

Termin

Vorsitzende

Programm

Poster sessionShort presentations – Stimulation

Termin

Vorsitzende

Programm

Poster session
Short presentations – Stimulation