75. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie

Vorsitz

Prof. Dr.

Prof.

Interictal epileptiform discharges in the hippocampus are biomarkers of memory dysfunction in epilepsy and Alzheimer's disease

Funktionelle Neurochirurgie und Schmerz 

Interictale Spikes im Hippocampus als Biomarker für Gedächtnisstörungen für Epilepsie und Alzheimer Demenz

Cognitive impairment is common in patients with epilepsy (PWE) and can severely affect the quality of life. Interictal epileptiform discharges (IEDs) are transient abnormal electrophysiological events happening between seizures associated with transient cognitive impairment in PWE and observed in patients and rodents with Alzheimer"s disease (AD). IEDs interfere with physiologic oscillations during sleep that are necessary for memory consolidation, specifically hippocampal sharp-wave ripples (SPW-Rs) and cortical spindles. Recently we demonstrated a negative effect of IEDs on memory consolidation and hippocampal SWRs in the hippocampal CA1 region in an AD mouse model. Here we aim to characterize the negative impact of IEDs in other hippocampal subfields as well as their clinical relevance.We compared the spread of IEDs their impact on neuronal firing in the hippocampus in two distinct settings. First, we investigated hippocampal and parahippocampal IEDs in epilepsy patients implanted with combined micro/macrowire intracranial EEG electrodes for surgical resection planning, including patients with temporal (n=8) and extratemporal (n=7) epilepsy focus. Next, we obtained high-density recordings from the entire dorsal hippocampus (1024 Channel, SiNAPS Probes, Neuronexus) from adult AD transgenic mice (APP/S1, n=5).We observed IEDs in the hippocampus of epilepsy patients with temporal and frontal lobe foci and in AD mice, independent of seizure generation or seizure onset zone. SWRs were only detected on electrodes in the CA1 and CA2 regions in all rodents and only in a subset of patients, possibly because of location of the recording electrode outside the CA1/CA2 region. By contrast IEDs were easily detected in the human microwire recordings. IEDs showed similar local field potential features and waveforms in both subject groups, and quickly generalized across channels, leading to global supression of neuronal firing rates, that could be associated with interruption of physiologic signaling. The high-density rodent recordings demonstrated that the IED spread respected anatomical pathways.We propose that IEDs may be a suitable biomarker for treatment of memory disorders in epilepsy and Alzheimer's Disease by targeted closed-loop stimulation, because of their impact on neuronal firing and easy detection.

Abstractvortrag | Abstract talk

PD Dr.

Prof. Dr. med.

Seizure outcome after epilepsy surgery for ganglioglioma – A multicenter analysis

Anfallsoutcome nach Epilepsiechirurgie für Gangliogliomen – eine multizentrische Analyse

Gangliogliomas are the most frequent glioneuronal tumors causing drug-resistant epilepsy. We investigated a large series of gangliogliomas with a focus on predictors for epilepsy outcomes.We identified 201 patients with a history of pharmacoresistant epilepsy and a confirmed ganglioglioma after epilepsy surgery. Data were obtained at three large epilepsy centers in Germany. Relevant clinical data and follow-up information were retrospectively extracted from patients" records.A total of 201 tumors presented with an accumulation of temporal location (n=159, 87%) and a balanced gender distribution (female n=99 49%). Epilepsy onset showed a median age of 13 years (6-19), and epilepsy surgery was performed at a median age of 22 years (15.0-34.8). At the last available follow-up, 147 (76 %) patients were seizure-free (ILAE 1). In 21 patients, ganglioglioma was associated with hippocampus sclerosis as well, which was addressed during the surgical resection but did not influence the final seizure outcome. Complete resection of the tumor could be achieved in 71.4% of the patients and showed a positive trend to influence the final seizure outcome (p=0.08). Molecular analysis revealed that only gangliogliomas harboring BRAFV600E mutations recurred during follow-up (p=0.04). Of note, tumor recurrence was the only clinical feature associated with a higher chance of seizure recurrence as well (p=0.007). Gangliogliomas are highly epileptogenic glioneuronal tumors. Surgery is an effective option to treat tumor-associated epilepsy, showing excellent seizure outcomes in 76% of the patients. Tumor recurrence was the only predictor associated with poor seizure outcome, and molecular analysis for BRAFV600E might help better stratify the patients at risk for recurrence.

Virtual reality (VR) augmented functional neuronavigation in pediatric epilepsy surgery: Does it facilitate resection, reduce complications, or improve seizure outcome?

Durch virtuelle Realität verstärkte funktionelle Neuronavigation für pediatrische Epilepsiechirurgie: Erleichtert es die Resektion, reduziert es Komplikationen oder verbessert es die Anfallsfreiheit?

Virtual reality (VR) is increasingly being used to improve surgical planning and assist in real time surgical procedures. A retrospective investigation was conducted to investigate its role in pediatric epilepsy surgery at our institution.Functional neuronavigation using multimodal imaging data (fMRI, DTI-tractography, PET, SPECT, sEEG) were used to augment the surgical navigation by transferring 3D imaging reconstructions as VR maps into the surgical microscope during surgery. Additionally, a navigated suction tool used for surgery was displayed in the virtual reality display and used for orientation during surgery. Real time augmentation of the surgery was performed using this dynamic VR information.Altogether, 43 patients (17 female, 0-18 yrs, mean 9 yrs) were operated between 10/2020 and 10/2023 and fulfilled all inclusion criteria. 26 patients (60.5%) had an extra-temporal and 17 (39.5%) a temporal seizure origin. Preoperative MRI studies were negative in 11 patients (25.6%), which necessitated implantation of depth electrodes before resection. Advantages of VR augmentation comprised: 1. on-line targeting of the lesions, 2. avoiding injury of eloquent structures, 3. contour-guided resection of lesions even in cases with unclear visual delineation, and 4. estimation of the resection amount at the end of surgery. Altogether, of 25 patients with a follow up of over one year, 83% displayed a favorable seizure outcome with ILAE 1 (75% ILAE 1a). One patient was found to have postoperative hemianopia, but no complications leading to surgical revision were encountered. VR augmented microscope resection facilitated targeting and removal of lesional as well as non-lesional (sEEG guided) epileptogenic zones in pediatric epilepsy surgery with low morbidity and a remarkably good seizure outcome.

Dr.med.

Dr. Dr.

Beyond the lesion: stereoelectroencephalography (SEEG) evaluation and predictors for post-operative seizure outcome in resective epilepsy surgery

Jenseits der Läsion: Stereoelektroenzephalographie (SEEG)-Evaluation und Prädiktoren für das postoperative Anfallsoutcome nach resektiver Epilepsiechirurgie

It is often assumed that patients with refractory epilepsy requiring invasive pre-surgical evaluation using stereoelectroencephalography (SEEG) prior to epilepsy surgery have a lower chance of achieving seizure freedom postoperatively. However, some predictors have been proposed, and their impact on postoperative seizure freedom is controversially discussed. The aim of this study is to identify factors in patients undergoing invasive pre-surgical evaluation that influence postoperative seizure outcomes following resective epilepsy surgery.In this retrospective single-center study, we included all patients with pharmacoresistant epilepsy who underwent resective epilepsy surgery following invasive pre-surgical evaluation using SEEG between 2012 and 2022. Seizure outcome was determined according to the ILAE classification with a follow-up of at least one year after the epilepsy surgery. Patients were divided into two groups according to their postoperative seizure outcomes: seizure-free (SF) and not seizure-free (non-SF). Both groups were analyzed and compared regarding factors determining seizure outcome.83(72.8%) of a total of 114 patients were seizure-free (SF) and 31(27.2%) were not seizure-free (non-SF) after epilepsy surgery. The comparison of both groups shows that patient characteristics such as age at surgery, sex, BMI, and ASA-score statistically had no impact on post-operative seizure outcome. Univariate analysis revealed that non-lesional MRI scan prior to evaluation (p=0.002), detected peri-operative complications according to MRI scan after completing the SEEG monitorung (p=0.006) and selective amygdalo-hippocampectomy as chosen resective approach (p=0.010) was significantly more often associated with a non-seizure-free outcome. Multivariate analysis revealed the non-lesional MRI scan (p=0.008, OR 6.4, CI 95% 1.6-25.4) and post-operative complications depicted on MRI scan during the SEEG evaluation (p=0.024, OR 8.2, CI 95% 1.0-8.5) as independent risk factors for the non-seizure-free outcome.In this study, we demonstrate that patients with a non-lesional MRI, who were pre-surgically evaluated using SEEG and had an identified epileptogenic focus, showed a significantly higher risk of not achieving seizure freedom following resective epilepsy surgery. Furthermore, the detection of peri-operative complications in the MRI scan following the completion of the SEEG evaluation was a statistically significant predictor of non-seizure-free outcome.

MUDr.

Dr. med. univ.

Long-Term impact of hypoglossal nerve stimulation on quality of life and mood in obstructive sleep apnea

Langzeitauswirkungen der Stimulation des Hypoglossusnervs auf Lebensqualität und Stimmungslage bei obstruktiver SchlafapnoeLong

Obstructive sleep apnea is associated with significant morbidity and mortality. Poor sleep quality has a significant impact on the patient's quality of life and mental health. Hypoglossal nerve stimulation (HNS) represents a neurosurgical option for individuals who exhibit inadequate responses to standard treatment. Although the positive effects of nerve stimulation on objective measures such as the apnea-hypopnea index (AHI) have been observed, the long-term effects on quality of life and mood have not yet been investigated.A single-center prospective analysis including twelve patients undergoing unilateral HNS (Inspire Medical Systems, Inc, Maple Grove, Minnesota) was performed between 2020 and 2024. All participants were assessed using the Becks Depression Inventory score (BDI-II) for mood evaluation, and the Quality-of-Life Scale questionnaire (QoL) at baseline, six months, and more than two years after stimulator activation. Patients were dichotomously stratified based on the degree of treatment success, defined as achieving a postoperative AHI of ≤ 20 events/h, with a reduction of at least 50% compared to baseline.All participants completed the six-month follow-up, while three patients were lost to follow-up at over 2 years. The average follow-up time was 30.8 months. Five out of twelve patients were classified as non-responders. Mean BDS-II scores were 0.77, 0.49, and 0.42 (p < 0.05), and mean QoL scores were 4.93, 4.84, and 5.2 at the respective time points. Noteworthy differences in the QoL domain were seen in autonomy, family relationships, and close friends. In the BDS-II domain, significant improvements were noted in change in sleep habits, irritability, and suicidal thoughts, among others. Non-responders exhibited elevated BDI-II scores in 18/21, 20/21, and 17/21 categories, and demonstrated higher dissatisfaction rates in 13/16, 8/16, and 11/16 cases at the respective follow-up points.Apart from measurable parameters such as AHI, there is a positive influence of HNS on the quality of life, particularly with more positive outcomes observed over a two-year period. As a subgroup, responders consistently exhibited higher satisfaction levels and lower BDI-II scores at all follow-up points. A slower or poorer response in satisfaction and mood should not be prematurely interpreted as treatment failure. Instead, the enhancement and restoration of quality of life seem to unfold gradually in the long-term trajectory.

Dr. med.

Hypoglossal nerve stimulation as an alternative in the therapy of obstructive sleep apnea

Periphere Nerven

Hypoglossus nerv Stimulation als Alternative in der Therapie der Obstructiven Schlafapnoe

Due to the very poor therapy acceptance and the side effects of CPAP therapy in obstructive sleep apnea, there is a great need for alternatives. Hypoglossal stimulation represents a new therapy option that has been available since 2016. In this study, we would like to present our initial results from 53 patients with implanted hypoglossal stimulators.In the period from August 2016 to December 2023, we were able to evaluate the data from 52 patients with respiratory sensor-triggered hypoglossal stimulators that were implanted by us. The pre- and postoperative AHI was determined using polygraphy and polysomnography, the pre- and postoperative daytime sleepiness using the Epworth Sleepiness Scale (ESS) and patient satisfaction were determined.In 48 out of 52 patients (92.3%), we observed a reduction in AHI under stimulation by over 60%. Four patients did not tolerate this therapy or did not use it regularly. Twenty-six patients (47.3%) achieved a reduction in AHI of over 80% from the baseline value. Regarding daytime sleepiness, there was an average reduction in the ESS score from 10 to 6.5. The subjectively reported satisfaction with sleep improved by 66.3% in 43 evaluable patients.Stimulating the hypoglossal nerve for the treatment of OSA (obstructive sleep apnea) provides a viable alternative to CPAP/PAP therapy. With strict indications, an acceptable reduction in AHI (apnea-hypopnea index) can be achieved. Daytime sleepiness is effectively treated, and the subjectively perceived sleep quality improves. This is a new and emerging technology with the potential to replace PAP therapy in the coming years.

Session 21
Funktionelle Neurochirurgie – Epilepsie

Termin

Vorsitz

Thema

Programm

Session 21Funktionelle Neurochirurgie – Epilepsie

Termin

Vorsitz

Thema

Programm

Session 21
Funktionelle Neurochirurgie – Epilepsie