Directed and acyclic synaptic connectivity in the human layer 2-3 cortical microcircuit.

The computational capabilities of neuronal networks are fundamentally constrained by their specific connectivity. Previous studies of cortical connectivity have mostly been carried out in rodents; whether the principles established therein also apply to the evolutionarily expanded human cortex is unclear. We studied network properties within the human temporal cortex using samples obtained from brain surgery. We analyzed multineuron patch-clamp recordings in layer 2-3 pyramidal neurons and identified substantial differences compared with rodents. Reciprocity showed random distribution, synaptic strength was independent from connection probability, and connectivity of the supragranular temporal cortex followed a directed and mostly acyclic graph topology. Application of these principles in neuronal models increased dimensionality of network dynamics, suggesting a critical role for cortical computation.

Cortical Thickness Patterns of Cognitive Impairment Phenotypes in Drug-Resistant Temporal Lobe Epilepsy.

OBJECTIVE: In temporal lobe epilepsy (TLE), a taxonomy classifying patients into 3 cognitive phenotypes has been adopted: minimally, focally, or multidomain cognitively impaired (CI). We examined gray matter (GM) thickness patterns of cognitive phenotypes in drug-resistant TLE and assessed potential use for predicting postsurgical cognitive outcomes. METHODS: TLE patients undergoing presurgical evaluation were categorized into cognitive phenotypes. Network edge weights and distances were calculated using type III analysis of variance F-statistics from comparisons of GM regions within each TLE cognitive phenotype and age- and sex-matched healthy participants. In resected patients, logistic regression models (LRMs) based on network analysis results were used for prediction of postsurgical cognitive outcome. RESULTS: A total of 124 patients (63 females, mean age ± standard deviation [SD] = 36.0 ± 12.0 years) and 117 healthy controls (63 females, mean age ± SD = 36.1 ± 12.0 years) were analyzed. In the multidomain CI group (n = 66, 53.2%), 28 GM regions were significantly thinner compared to healthy controls. Focally impaired patients (n = 37, 29.8%) showed 13 regions, whereas minimally impaired patients (n = 21, 16.9%) had 2 significantly thinner GM regions. Regions affected in both multidomain and focally impaired patients included the anterior cingulate cortex, medial prefrontal cortex, medial temporal, and lateral temporal regions. In 69 (35 females, mean age ± SD = 33.6 ± 18.0 years) patients who underwent surgery, LRMs based on network-identified GM regions predicted postsurgical verbal memory worsening with a receiver operating curve area under the curve of 0.70 ± 0.15. INTERPRETATION: A differential pattern of GM thickness can be found across different cognitive phenotypes in TLE. Including magnetic resonance imaging with clinical measures associated with cognitive profiles has potential in predicting postsurgical cognitive outcomes in drug-resistant TLE. ANN NEUROL 2024;95:984-997.

Differential contribution of THIK-1 K+ channels and P2X7 receptors to ATP-mediated neuroinflammation by human microglia.

Neuroinflammation is highly influenced by microglia, particularly through activation of the NLRP3 inflammasome and subsequent release of IL-1ß. Extracellular ATP is a strong activator of NLRP3 by inducing K+ efflux as a key signaling event, suggesting that K+-permeable ion channels could have high therapeutic potential. In microglia, these include ATP-gated THIK-1 K+ channels and P2X7 receptors, but their interactions and potential therapeutic role in the human brain are unknown. Using a novel specific inhibitor of THIK-1 in combination with patch-clamp electrophysiology in slices of human neocortex, we found that THIK-1 generated the main tonic K+ conductance in microglia that sets the resting membrane potential. Extracellular ATP stimulated K+ efflux in a concentration-dependent manner only via P2X7 and metabotropic potentiation of THIK-1. We further demonstrated that activation of P2X7 was mandatory for ATP-evoked IL-1ß release, which was strongly suppressed by blocking THIK-1. Surprisingly, THIK-1 contributed only marginally to the total K+ conductance in the presence of ATP, which was dominated by P2X7. This suggests a previously unknown, K+-independent mechanism of THIK-1 for NLRP3 activation. Nuclear sequencing revealed almost selective expression of THIK-1 in human brain microglia, while P2X7 had a much broader expression. Thus, inhibition of THIK-1 could be an effective and, in contrast to P2X7, microglia-specific therapeutic strategy to contain neuroinflammation.

Defining benchmark outcomes for mesial temporal lobe epilepsy surgery: A global multicenter analysis of 1119 cases.

OBJECTIVE: Benchmarking has been proposed to reflect surgical quality and represents the highest standard reference values for desirable results. We sought to determine benchmark outcomes in patients after surgery for drug-resistant mesial temporal lobe epilepsy (MTLE). METHODS: This retrospective multicenter study included patients who underwent MTLE surgery at 19 expert centers on five continents. Benchmarks were defined for 15 endpoints covering surgery and epilepsy outcome at discharge, 1 year after surgery, and the last available follow-up. Patients were risk-stratified by applying outcome-relevant comorbidities, and benchmarks were calculated for low-risk ("benchmark") cases. Respective measures were derived from the median value at each center, and the 75th percentile was considered the benchmark cutoff. RESULTS: A total of 1119 patients with a mean age (range) of 36.7 (1-74) years and a male-to-female ratio of 1:1.1 were included. Most patients (59.2%) underwent anterior temporal lobe resection with amygdalohippocampectomy. The overall rate of complications or neurological deficits was 14.4%, with no in-hospital death. After risk stratification, 377 (33.7%) benchmark cases of 1119 patients were identified, representing 13.6%-72.9% of cases per center and leaving 742 patients in the high-risk cohort. Benchmark cutoffs for any complication, clinically apparent stroke, and reoperation rate at discharge were ≤24.6%, ≤.5%, and ≤3.9%, respectively. A favorable seizure outcome (defined as International League Against Epilepsy class I and II) was reached in 83.6% at 1 year and 79.0% at the last follow-up in benchmark cases, leading to benchmark cutoffs of ≥75.2% (1-year follow-up) and ≥69.5% (mean follow-up of 39.0 months). SIGNIFICANCE: This study presents internationally applicable benchmark outcomes for the efficacy and safety of MTLE surgery. It may allow for comparison between centers, patient registries, and novel surgical and interventional techniques.

Non-discontinuation of antiseizure medication in seizure-free epilepsy patients.

BACKGROUND AND PURPOSE: In patients with epilepsy and sustained seizure freedom, guidelines recommend considering discontinuation of antiseizure medication (ASM) based on shared decision-making. This study aims to identify factors associated with non-discontinuation of ASM in seizure-free patients. METHODS: Retrospective data from three sites of an academic outpatient clinic were analyzed. Adult patients with epilepsy who have been seizure-free for ≥24 months on ASM monotherapy were included. The primary end-point was non-discontinuation of ASM, defined as no discontinuation or no dose reduction of ≥25% at the last outpatient clinic visit in the ultimate seizure-free interval. Secondary end-points included frequency of discussion on discontinuation attempts between patients and physicians, adherence to ASM discontinuation decisions, and post-discontinuation seizure outcomes. RESULTS: Out of 338 included patients, 81.7% did not discontinue ASM and did not reduce its dose, 11.5% discontinued ASM and 6.8% had a significant dose reduction. Factors independently associated with non-discontinuation of ASM were history of focal to bilateral or generalized tonic-clonic seizures (odds ratio [OR] 2.33, 95% confidence interval [CI] 1.08-5.06), history of breakthrough seizures (OR 3.32, 95% CI 1.10-10.04), history of failed attempts to discontinue or reduce the ASM dose (OR 4.67, 95% CI 1.03-21.11) and higher ASM load at the index visit (OR 6.10, 95% CI 2.09-17.78). Discontinuation attempts were made during the entire period of seizure freedom and were most commonly undertaken ≥10 years after the last seizure. CONCLUSIONS: This study provides insights into factors associated with the shared decision-making process regarding ASM discontinuation in seizure-free patients and highlights the importance of considering individual patient characteristics and seizure history.

Epilepsy with generalized tonic-clonic seizures alone: Electroclinical features and prognostic patterns.

OBJECTIVE: Epilepsy with generalized tonic-clonic seizures alone (GTCA) is a common but poorly characterized idiopathic generalized epilepsy (IGE) syndrome. Hence, we investigated electroclinical features, seizure outcome, and antiseizure medication (ASM) withdrawal in a large cohort of GTCA patients. METHODS: In this multicenter retrospective study, GTCA patients defined according to the diagnostic criteria of the International League Against Epilepsy (2022) were included. We investigated prognostic patterns, drug resistance at the last visit, and ASM withdrawal, along with their prognostic factors. RESULTS: We included 247 patients with a median (interquartile range [IQR]) age at onset of 17 years (13-22) and a median follow-up duration of 10 years (IQR = 5-20). Drug resistance at the last visit was observed in 40 (16.3%) patients, whereas the median latency to achieve 2-year remission was 24 months (IQR = 24-46.5) with a median number of 1 (IQR = 1-2) ASM. During the long-term follow-up (i.e., 202 patients followed ≥5-years after the first ASM trial), 69 (34.3%) patients displayed an early remission pattern and 36 (17.9%) patients displayed a late remission pattern, whereas 16 (8%) and 73 (36.3%) individuals had no-remission and relapsing-remitting patterns, respectively. Catamenial seizures and morning predominance of generalized tonic-clonic seizures (GTCS) independently predicted drug resistance at the last visit according to multivariable logistic regression. Treatment withdrawal was attempted in 63 (25.5%) patients, with 59 (93.7%) of them having at least a 12-month follow-up after ASM discontinuation. At the last visit, 49 (83%) of those patients had experienced GTCS recurrence. A longer duration of seizure freedom was the only factor predicting a higher chance of successful ASM withdrawal according to multivariable Cox regression. SIGNIFICANCE: GTCA could be considered a relatively easily manageable IGE syndrome, with a low rate of drug resistance and a high prevalence of early response to treatment. Nevertheless, a considerable proportion of patients experience relapsing patterns of seizure control, highlighting the need for appropriate counseling and lifestyle recommendations.

German questionnaires assessing quality of life and psycho-social status in people with epilepsy: Reliable change and intercorrelations.

OBJECTIVES: People with epilepsy (PWE) not only suffer from seizures but also from various psycho-social issues containing facets such as social functioning, anxiety, depression or stigmatization, and consequently quality of life. (1) Assessing reliable change of these issues is crucial to evaluate their course and potential treatment effects. As most psycho-social self-report questionnaires have been validated in separate samples, their clinical-socio-demographic differences may limit the comparability and generalizability of the scales' internal consistency, which is important for the reliable change index (RCI). Using a co-normalized approach, we provide the internal consistency and RCIs for a large set of questionnaires targeting quality of life (QOLIE-31-P), depressive symptoms (NDDI-E), anxiety (GAD-7), seizure severity (LSSS), subjective antiseizure medication adverse events (LAEP), stigma, epilepsy-related fear, and restrictions in daily life (PESOS), and subjective cognition (FLei). As for some German versions of these measures, psychometric data is still missing, we also add important information for the German language area. (2) In addition, knowledge about intercorrelations of these constructs is needed to shape questionnaire usage and treatment approaches. We thus investigate associations of these scales and compare weighted and unweighted subscales of the QOLIE-31-P. METHODS: In our prospective study, 202 adult in-patients of the Epilepsy-Center Berlin-Brandenburg with a reliable diagnosis of epilepsy filled out a set of self-report questionnaires between 03/2018 and 03/2021. We calculated Cronbach's α, RCIs, and bivariate intercorrelations and compared the respective correlations of weighted and unweighted scales of the QOLIE-31-P. RESULTS: For most of the scales, good to excellent internal consistency was identified. Furthermore, we found intercorrelations in the expected directions with strong links between scales assessing similar constructs (e.g., QOLIE-31-P Cognition and FLei), but weak relationships between measures for different constructs (e.g., QOLIE-31-P Seizure worry and FLei). The QOLIE-31-P Total score was highly correlated with most of the other scales. Some differences regarding their correlational patterns for weighted and unweighted QOLIE-31-P scales were identified. CONCLUSIONS: Psycho-social constructs share a large amount of common variance, but still can be separated from each other. The QOLIE-31-P Total score represents an adequate measure of general psycho-social burden.

Generalized onset seizures with focal evolution (GOFE) - a largely unknown ictal variation in genetic generalized epilepsies.

PURPOSE: At onset of generalized seizures, focal electroclinical features are commonly seen, while generalized onset seizures with focal evolution (GOFE) are largely unknown bearing the risk of misclassification. METHODS: In two German epilepsy-centers, patients with GOFE documented by video-EEG monitoring (VEM) between 2017 and 2022 were identified retrospectively. In addition to analysis of ictal electroclinical features, detailed epilepsy and family history, response to antiseizure medication (ASM), and findings from neuroimaging were considered. RESULTS: We identified five patients with GOFE, three females, age 14 to 22 years. All patients developed genetic generalized epilepsy in childhood or adolescence, each presenting with two or three generalized seizure types. In each of the five patients, one GOFE was recorded by VEM. At onset, EEG seizure patterns were characterized by generalized spike-wave discharges at 2.5 to 3.5/sec for 9 to 16 s followed by focal evolution of the discharges. Interictally, all patients presented with generalized spike-wave discharges without focal abnormalities. Semiology at onset was behavioral arrest in two patients and generalized increase in tone in one, while two onsets were clinically inapparent. Semiological signs during focal evolution were variable, comprising head and body version, figure 4 sign, unilateral arm clonic activity, and staring with oral automatisms. In one case, focality involved both hemispheres successively. CONCLUSION: Prominent focal semiological features in GOFE carry a high risk of misclassification as focal seizures and epilepsy and thus wrong choice of ASM. This calls for low-threshold VEM if any doubts of focal genesis of seizures exist.

Prognosis and management of acute symptomatic seizures: a prospective, multicenter, observational study.

BACKGROUND: Acute symptomatic epileptic seizures are frequently seen in neurocritical care. To prevent subsequent unprovoked seizures, long-term treatments with antiseizure medications are often initiated although supporting evidence is lacking. This study aimed at prospectively assessing the risk of unprovoked seizure relapse with respect to the use of antiseizure medications. It was hypothesized that after a first acute symptomatic seizure of structural etiology, the cumulative 12-month risk of unprovoked seizure relapse is ≤ 25%. METHODS: Inclusion criteria were age ≥ 18 and acute symptomatic first-ever epileptic seizure; patients with status epilepticus were excluded. Using telephone and mail interviews, participants were followed for 12 months after the acute symptomatic first seizure. Primary endpoint was the occurrence and timing of a first unprovoked seizure relapse. In addition, neuro-intensivists in Germany were interviewed about their antiseizure treatment strategies through an anonymous online survey. RESULTS: Eleven of 122 participants with structural etiology had an unprovoked seizure relapse, resulting in a cumulative 12-month risk of 10.7% (95%CI, 4.7%-16.7%). None of 19 participants with a non-structural etiology had a subsequent unprovoked seizure. Compared to structural etiology alone, combined infectious and structural etiology was independently associated with unprovoked seizure relapse (OR 11.1; 95%CI, 1.8-69.7). Median duration of antiseizure treatment was 3.4 months (IQR 0-9.3). Seven out of 11 participants had their unprovoked seizure relapse while taking antiseizure medication; longer treatment durations were not associated with decreased risk of unprovoked seizure relapse. Following the non-representative online survey, most neuro-intensivists consider 3 months or less of antiseizure medication to be adequate. CONCLUSIONS: Even in case of structural etiology, acute symptomatic seizures bear a low risk of subsequent unprovoked seizures. There is still no evidence favoring long-term treatments with antiseizure medications. Hence, individual constellations with an increased risk of unprovoked seizure relapse should be identified, such as central nervous system infections causing structural brain damage. However, in the absence of high-risk features, antiseizure medications should be discontinued early to avoid overtreatment.

Lipid profile with eslicarbazepine acetate and carbamazepine monotherapy in adult patients with newly diagnosed focal seizures: post hoc analysis of a phase III trial and open-label extension study.

Background: Antiseizure medications can have negative effects on plasma lipid levels. Objectives: To evaluate plasma lipid changes in patients with newly diagnosed focal epilepsy treated with eslicarbazepine acetate (ESL) or controlled-release carbamazepine (CBZ-CR) monotherapy during a phase III, randomized, double-blind (DB) trial and 2 years of ESL treatment in an open-label extension (OLE). Design: Post hoc analysis of a phase III trial and OLE study. Methods: Proportions of patients with elevated levels of total cholesterol and low-density lipoprotein (LDL) cholesterol were assessed at DB baseline, OLE baseline (last visit of DB trial), and end of OLE. Results: A total of 184 patients received ESL monotherapy during the OLE: 96 received ESL monotherapy in the DB trial and 88 patients received CBZ-CR monotherapy. The proportions of patients with elevated total cholesterol and LDL cholesterol increased significantly during the DB trial in those treated with CBZ-CR monotherapy [total cholesterol, +14.9% (p < 0.001); LDL cholesterol, +11.5% (p = 0.012)] but decreased significantly after switching to ESL monotherapy in the OLE [total cholesterol, -15.3% (p = 0.008); LDL cholesterol, -11.1% (p = 0.021)]. No significant changes were observed in those treated with ESL monotherapy during the DB trial and OLE. At the end of the DB trial, between-group differences (ESL-CBZ-CR) in the proportions of patients with elevated total and LDL cholesterol were -13.6% (p = 0.037) and -12.3% (p = 0.061), respectively; at the end of the OLE, these between-group differences were -6.0% (p = 0.360) and -0.6% (p = 1.000), respectively. Conclusion: A lower proportion of patients with newly diagnosed focal epilepsy had increased levels of total and LDL cholesterol, compared to baseline, following monotherapy with ESL versus CBZ-CR; after switching from CBZ-CR to ESL, the proportions of patients with increased levels decreased significantly. Registration: ClinicalTrials.gov NCT01162460/NCT02484001; EudraCT 2009-011135-13/2015-001243-36.

The impact of treatment with either eslicarbazepine acetate or controlled-release carbamazepine on cholesterol levels in patients with newly diagnosed focal epilepsy Patients with epilepsy have an increased risk of having cardiovascular and cerebrovascular diseases (e.g., myocardial infarction and stroke). Treatment with antiseizure medications can have a negative effect on blood cholesterol levels [such as total cholesterol and low-density lipoprotein (LDL) cholesterol], which can further increase the risk of cardiovascular and cerebrovascular diseases. We examined the impact of monotherapy treatment (i.e., treatment with only one antiseizure medication) using either eslicarbazepine acetate (ESL) or a controlled-release formulation of carbamazepine (CBZ-CR) in 184 patients with newly diagnosed focal epilepsy (ESL, 96 patients; CBZ-CR, 88 patients). Patients received monotherapy with ESL or CBZ-CR for approximately 1 year in a phase III clinical trial. After this, the patients could continue into a 2-year extension study during which they all received monotherapy with ESL. We assessed the proportions of patients with elevated levels of total cholesterol and LDL cholesterol at the beginning and end of the phase III trial, and at the end of the extension study. At the beginning of the phase III trial, the proportions of patients with elevated total cholesterol and elevated LDL cholesterol were similar between treatment groups. During the phase III trial, the proportions of patients with elevated total cholesterol and elevated LDL cholesterol increased in those treated with CBZ-CR monotherapy (total cholesterol, +14.9%; LDL cholesterol, +11.5%) but decreased after switching to ESL monotherapy in the extension study (total cholesterol, −15.3%; LDL cholesterol, −11.1%). By contrast, the proportions of patients with elevated levels of total cholesterol and LDL cholesterol remained relatively stable in those treated with ESL monotherapy during the phase III trial and extension study. These findings indicate that ESL monotherapy may be an appropriate treatment option for patients with newly diagnosed focal epilepsy who either already have, or who are at risk of developing, high levels of cholesterol, since this may reduce their likelihood of having cardiovascular and cerebrovascular diseases.

High frequency of cerebrospinal fluid autoantibodies in patients with seizures or epilepsies of unknown etiology.

Introduction: The increasing identification of specific autoantibodies against brain structures allows further refinement of the group of autoimmune-associated epilepsies and affects diagnostic and therapeutic algorithms. The early etiological allocation of a first seizure is particularly challenging, and the contribution of cerebrospinal fluid (CSF) analysis is not fully understood. Methods: In this retrospective study with a mean of 7.8 years follow-up involving 39 well-characterized patients with the initial diagnosis of new-onset seizure or epilepsy of unknown etiology and 24 controls, we determined the frequency of autoantibodies to brain proteins in CSF/serum pairs using cell-based assays and unbiased immunofluorescence staining of unfixed murine brain sections. Results: Autoantibodies were detected in the CSF of 30.8% of patients. Underlying antigens involved glial fibrillary acidic protein (GFAP) and N-methyl-D-aspartate (NMDA) receptors, but also a range of yet undetermined epitopes on neurons, glial and vascular cells. While antibody-positive patients had higher frequencies of cancer, they did not differ from antibody-negative patients with respect to seizure type, electroencephalography (EEG) and cranial magnetic resonance imaging (cMRI) findings, neuropsychiatric comorbidities or pre-existing autoimmune diseases. In 5.1% of patients with seizures or epilepsy of initially presumed unknown etiology, mostly CSF findings resulted in etiological reallocation as autoimmune-associated epilepy. Discussion: These findings strengthen the potential role for routine CSF analysis. Further studies are needed to understand the autoantibody contribution to etiologically unclear epilepsies, including determining the antigenic targets of underlying autoantibodies.

Epileptogenicity of white matter lesions in cerebral small vessel disease: a systematic review and meta-analysis.

BACKGROUND: The epileptogenic properties of white matter lesions (WML) in cerebral small vessel disease (CSVD) are not yet understood. The aim of our systematic review and meta-analysis was to estimate the association between the extent of WML in CSVD and epilepsy, analyze whether these WML are associated with an increased risk of seizure recurrence, and evaluate if treatment with anti-seizure medication (ASM) is justified in first-seizure patients with WML and no cortical lesions. METHODS: Following a pre-registered study protocol (PROSPERO-ID CRD42023390665), we systematically searched Pubmed and Embase for relevant literature comparing WML load between patients with epilepsy and controls as well as studies on seizure recurrence risk and ASM therapy in the presence vs. absence of WML. We calculated pooled estimates using a random effects model. RESULTS: Eleven studies comprising 2983 patients were included in our study. Presence of WML (OR 2.14, 95% CI 1.38-3.33) and presence of relevant WML as assessed by visual rating scales (OR 3.96, 95% CI 2.55-6.16) but not WML volume (OR 1.30, 95% CI 0.91-1.85) were significantly associated with seizures. These results stayed robust in sensitivity analyses restricted to studies on patients with late-onset seizures/epilepsy. Only two studies assessed the association between WML and risk of seizure recurrence with conflicting results. Currently, there are no studies on the efficacy of ASM therapy in the presence of WML in CSVD. CONCLUSIONS: This meta-analysis suggests an association between presence of WML in CSVD and seizures. More research is needed addressing the association between WML and risk of seizure recurrence and ASM therapy focusing on a population of patients with a first unprovoked seizure.

Integration of interictal EEG source localization in presurgical epilepsy evaluation - A single-center prospective study.

OBJECTIVE: To investigate cost in working hours for initial integration of interictal EEG source localization (ESL) into clinical practice of a tertiary epilepsy center, and to examine concordance of results obtained with three different ESL pipelines. METHODS: This prospective study covered the first year of using ESL in the Epilepsy-Center Berlin-Brandenburg. Patients aged ≥14 years with drug-resistant focal epilepsy referred for noninvasive presurgical evaluation were included. Interictal ESL was based on low-density EEG and individual head models. Source maxima were obtained from two freely available software packages and one commercial provider. One physician and computer scientist documented their working hours for setting up and processing ESL. Additionally, a survey was conducted among epilepsy centers in Germany to assess the current role of ESL in presurgical evaluation. RESULTS: Of 40 patients included, 22 (55%) had enough interictal spikes for ESL. The physician's working times decreased from median 4.7 hours [interquartile range 3.9-6.4] in the first third of cases to 2.0 hours [1.9-2.4] in the remaining two thirds; P < 0.01. In addition, computer scientist and physician spent a total of 35.5 and 33.0 working hours on setting up the digital infrastructure, and on training and testing. Sublobar agreement between all three pipelines was 20%, mean measurement of agreement (kappa) 0.13. Finally, the survey revealed that 53% of epilepsy centers in Germany currently use ESL for presurgical evaluation. SIGNIFICANCE: This study provides information regarding expected effort and costs for integration of ESL into an epilepsy surgery program. Low result agreement across different ESL pipelines calls for further standardization.

Domain-specific relationships of subjective and objective cognition in epilepsy.

OBJECTIVE: Many people with epilepsy report subjective cognitive impairment (SCI), i.e., problems with memory, attention, or executive functions, reducing quality of life. Nevertheless, overlap with objective cognitive impairment (OCI) is often weak. One reason may be a domain-specific mismatch between subjective reports and objective tests. We aimed to evaluate relations between SCI and OCI of corresponding domains and to assess whether these differ between persons who over- or underestimate their performance. METHODS: In this prospective, cross-sectional sample of 104 adult inpatients with epilepsy, we performed multiple regression analyses predicting SCI in the domains attention, memory, and executive functions. We tested relationships with measures of psychomotor speed, short-term memory, verbal learning, verbal delayed recall, and word fluency while controlling for age, sex, seizure frequency, structural lesions, mono- versus polytherapy and adverse events of antiseizure medication (ASM), depressive and anxiety symptoms, level of education, and employment status. Furthermore, we tested whether these relationships differed between realistic raters and over- and underestimators. RESULTS: We found domain-specific relations for attention and executive functions for the full sample, explaining a small proportion of variance of SCI (general dominance index = .03 and .004), whereas ASM adverse events and psychological variables were more important predictors. When dividing the sample according to the concordance of SCI and OCI, we found high frequencies of both over- (23%-46%) and underestimation (31%-35%) depending on the domain. The explanatory power of OCI for SCI was stronger within the subgroups compared to the full sample, suggesting nonlinear relationships and different underlying mechanisms for realistic raters, underestimators, and overestimators. SIGNIFICANCE: Domain-specific SCI and OCI are related, and both should be assessed with standardized instruments. These relationships differ between over- and underestimators as well as realistic raters. Based on the concordance of self-ratings and objective measures, tailored counseling and treatment should be offered.

Automatic and manual segmentation of the piriform cortex: Method development and validation in patients with temporal lobe epilepsy and Alzheimer's disease.

The piriform cortex (PC) is located at the junction of the temporal and frontal lobes. It is involved physiologically in olfaction as well as memory and plays an important role in epilepsy. Its study at scale is held back by the absence of automatic segmentation methods on MRI. We devised a manual segmentation protocol for PC volumes, integrated those manually derived images into the Hammers Atlas Database (n = 30) and used an extensively validated method (multi-atlas propagation with enhanced registration, MAPER) for automatic PC segmentation. We applied automated PC volumetry to patients with unilateral temporal lobe epilepsy with hippocampal sclerosis (TLE; n = 174 including n = 58 controls) and to the Alzheimer's Disease Neuroimaging Initiative cohort (ADNI; n = 151, of whom with mild cognitive impairment (MCI), n = 71; Alzheimer's disease (AD), n = 33; controls, n = 47). In controls, mean PC volume was 485 mm3 on the right and 461 mm3 on the left. Automatic and manual segmentations overlapped with a Jaccard coefficient (intersection/union) of ~0.5 and a mean absolute volume difference of ~22 mm3 in healthy controls, ~0.40/ ~28 mm3 in patients with TLE, and ~ 0.34/~29 mm3 in patients with AD. In patients with TLE, PC atrophy lateralised to the side of hippocampal sclerosis (p < .001). In patients with MCI and AD, PC volumes were lower than those of controls bilaterally (p < .001). Overall, we have validated automatic PC volumetry in healthy controls and two types of pathology. The novel finding of early atrophy of PC at the stage of MCI possibly adds a novel biomarker. PC volumetry can now be applied at scale.

Prediction of epilepsy surgery outcome using foramen ovale EEG - A machine learning approach.

INTRODUCTION: Patients with drug-resistant focal epilepsy may benefit from ablative or resective surgery. In presurgical work-up, intracranial EEG markers have been shown to be useful in identification of the seizure onset zone and prediction of post-surgical seizure freedom. However, in most cases, implantation of depth or subdural electrodes is performed, exposing patients to increased risks of complications. METHODS: We analysed EEG data recorded from a minimally invasive approach utilizing foramen ovale (FO) and epidural peg electrodes using a supervised machine learning approach to predict post-surgical seizure freedom. Power-spectral EEG features were incorporated in a logistic regression model predicting one-year post-surgical seizure freedom. The prediction model was validated using repeated 5-fold cross-validation and compared to outcome prediction based on clinical and scalp EEG variables. RESULTS: Forty-seven patients (26 patients with post-surgical 1-year seizure freedom) were included in the study, with 31 having FO and 27 patients having peg onset seizures. The area under the receiver-operating curve for post-surgical seizure freedom (Engel 1A) prediction in patients with FO onset seizures was 0.74 ± 0.23 using electrophysiology features, compared to 0.66 ± 0.22 for predictions based on clinical and scalp EEG variables (p < 0.001). The most important features for prediction were spectral power in the gamma and high gamma ranges. EEG data from peg electrodes was not informative in predicting post-surgical outcomes. CONCLUSION: In this hypothesis-generating study, a data-driven approach based on EEG features derived from FO electrodes recordings outperformed the predictive ability based solely on clinical and scalp EEG variables. Pending validation in future studies, this method may provide valuable post-surgical prognostic information while minimizing risks of more invasive diagnostic approaches.

Subjective cognition is linked to everyday functioning in epilepsy.

OBJECTIVE: Many people with epilepsy (PWE) suffer from reduced everyday functioning such as unemployment, relationship difficulties, or lifestyle limitations. To identify whether subjective cognitive impairment (SCI) is a potential source of these impairments, associations with restrictions of daily life (RDL) and reduced daily activities (DA) were examined. METHODS: In a prospective cross-sectional sample of 316 adult in-patients with epilepsy, multiple regression analyses were calculated predicting RDL and DA. The relationships between these two measures and SCI were controlled for age, sex, seizure frequency, presence of structural lesions, epilepsy duration, mono- vs polytherapy and adverse events of antiseizure medication (ASM), level of depressive and anxiety symptoms, education, and employment. We also checked for an interaction between depressive symptoms and SCI, to evaluate whether patients with more depressive symptoms are more vulnerable for unfavorable associations between SCI and RDL or DA, respectively. General dominance indices (GDIs) were calculated to compare predictors. RESULTS: Substantial SCI was present in 46% of our sample. SCI was independently associated with RDL and DA. Comparison of relative predictor importance revealed that SCI accounted for 23% of the total variance of RDL (GDISCI  = 0.12, R RDL 2  = 50%) and 24% of the total variance of DA (GDISCI  = 0.08, R DA 2  = 32%). SCI was among the two most important predictors in both models. PWE with more depressive symptoms had stronger associations between SCI and RDL or DA, respectively. SIGNIFICANCE: Subjective cognitive impairment represents a frequent concern in PWE and may have detrimental consequences for their everyday life. PWE with depressive symptoms may be at greater risk of unfavorable relationships between SCI and everyday functioning. Exchange and collaboration between professionals offering psychotherapeutic, neuropsychological, and psychosocial interventions are crucial to address the patients' individual needs.

How patients' psycho-social profiles contribute to decision-making in epilepsy surgery: A prospective study.

OBJECTIVE: Identifying factors associated with surgical decision-making is important to understand reasons for underutilization of epilepsy surgery. Neurologists' recommendations for surgery and patients' acceptance of these recommendations depend on clinical epilepsy variables, for example, lateralization and localization of seizure onset zones. Moreover, previous research shows associations with demographic factors, for example, age and sex. Here, we investigate the relevance of patients' psycho-social profile for surgical decision-making. METHODS: We prospectively studied 296 patients from two large German epilepsy centers. Multiple logistic regression analyses were used to investigate variables linked to neurologists' recommendations for and patients' acceptance of surgery or intracranial video-electroencephalographic monitoring. Patients' psycho-social profiles were assessed via self-reports and controlled for various clinical-demographic variables. Model selection was performed using the Akaike information criterion. RESULTS: As expected, models for neurologists' surgery recommendations primarily revealed clinical factors such as lateralization and localization of the seizure onset zone, load with antiseizure medication (ASM), and site of the epilepsy-center. For this outcome, employment was the only relevant psycho-social aspect (odds ratio [OR] = .38, 95% confidence interval [CI] = .13-1.11). In contrast, three of the five relevant predictors for patients' acceptance were psycho-social. Higher odds were found for those with more subjective ASM adverse events (OR = 1.04, 95% CI = .99-1.00), more subjective seizure severity (OR = 1.12, 95% CI = 1.01-1.24), and lower subjective cognitive impairment (OR = .98, 95% CI = .96-1.00). SIGNIFICANCE: We demonstrated the relevance of the patients' psycho-social profile for decision-making in epilepsy surgery, particularly for patients' decisions. Thus, in addition to clinical-demographic variables, patients' individual psycho-social characteristics add to the understanding of surgical decision-making. From a clinical perspective, this calls for individually tailored counseling to assist patients in finding the optimal treatment option.

Real-world data on cannabidiol treatment of various epilepsy subtypes: A retrospective, multicenter study.

OBJECTIVE: Cannabidiol (CBD) is approved for treatment of Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC). Several studies suggest antiseizure effects also beyond these three epilepsy syndromes. METHODS: In a retrospective multicenter study, we analyzed the efficacy and tolerability of CBD in patients with epilepsy at 16 epilepsy centers. RESULTS: The study cohort comprised 311 patients with epilepsy with a median age of 11.3 (0-72) years (235 children and adolescents, 76 adults). Therapy with CBD was off-label in 91.3% of cases due to age, epilepsy subtype, lack of adjunct therapy with clobazam, and/or higher dose applied. CBD titration regimens were slower than recommended, with good tolerability of higher doses particularly in children. Of all patients, 36.9% experienced a reduction in seizure frequency of >50%, independent of their epilepsy subtype or clobazam co-medication. The median observation period was 15.8 months. About one third of all patients discontinued therapy within the observation period due to adverse effects or lack of efficacy. Adverse effects were reported frequently (46.9%). SIGNIFICANCE: Our study highlights that CBD has an antiseizure effect comparable to other antiseizure medications with a positive safety profile independent of the epilepsy subtype. Comedication with clobazam was not associated with a better outcome. Higher doses to achieve seizure frequency reduction were safe, particularly in children. These findings call for further trials for an extended approval of CBD for other epilepsy subtypes and for children <2 years of age.