Heartbeat evoked potentials and autonomic arousal during dissociative seizures: insights from electrophysiology and neuroimaging.

Introduction: Dissociative seizures often occur in the context of dysregulated affective arousal and entail dissociative symptoms such as a disintegration of bodily awareness. However, the interplay between affective arousal and changes in interoceptive processing at the onset of dissociative seizures is not well understood. Methods: Using retrospective routine data obtained from video-electroencephalography telemetry in a university hospital epilepsy monitoring unit, we investigate ictal changes in cardiac indices of autonomic arousal and heartbeat evoked potentials (HEPs) in 24 patients with dissociative seizures. Results: Results show autonomic arousal during seizures with increased heart rate and a shift towards sympathetic activity. Compared with baseline, ictal HEP amplitudes over central and right prefrontal electrodes (F8, Fz) were significantly less pronounced during seizures, suggesting diminished cortical representation of interoceptive information. Significant correlations between heart rate variability measures and HEPs were observed at baseline, with more sympathetic and less parasympathetic activity related to less pronounced HEPs. Interestingly, these relationships weakened during seizures, suggesting a disintegration of autonomic arousal and interoceptive processing during dissociative seizures. In a subgroup of 16 patients, MRI-based cortical thickness analysis found a correlation with HEP amplitudes in the left somatosensory association cortex. Conclusions: These findings possibly represent an electrophysiological hint of how autonomic arousal could negatively impact bodily awareness in dissociative seizures, and how these processes might be related to underlying brain structure.

A multicenter randomized controlled feasibility trial of a digital self-management intervention for adults with epilepsy.

OBJECTIVE: Self-management interventions may enhance health-related quality of life (HRQoL) in epilepsy. However, several barriers often impair their implementation in the real world. Digital interventions may help to overcome some of these barriers. Considering this, the Helpilepsy Plus Prototype was developed as a prototype smartphone-delivered self-care treatment program for adults with epilepsy. METHODS: The 12-week Helpilepsy Plus Prototype was evaluated through a randomized controlled feasibility trial with a waiting-list control (WLC) group. Outcome measurement at baseline and at 12 weeks assessed adherence to the prototype intervention and changes in epilepsy-related outcomes. The primary endpoint was patient autonomy measured with EASE, and secondary endpoints included HRQoL measured with QOLIE-31, health literacy measured with HLQ, anxiety, and depression symptoms measured with HADS. Semi-structured interviews were conducted with a heterogeneous sample of participants to assess user-friendliness and usefulness. The prototype program was delivered through the Neuroventis Platform (Neuroventis, BV, Overijse, Belgium), a certified medical device (under EU/MDD Class I, and EU/MDR grace period). RESULTS: Ninety-two patients were included (46 in the intervention group, 46 in WLC). Most participants (63%, 58/92 women, median age 30 years) had pharmacoresistant epilepsy (61%, 56/92). Only 22% of participants (10/46) in the intervention group completed at least half of all intervention sessions. No significant differences between the intervention group and WLC were observed. Although there was a larger proportion of patients in the intervention group with meaningful improvements in HRQoL compared to WLC (19/46 versus 11/46), the difference was not significant (p = 0.119). Qualitative feedback showed that participants would appreciate more personalization, such as adaptation of the content to their current epilepsy knowledge level, a more interactive interface, shorter text sections, and interaction through reminders and notifications. SIGNIFICANCE: Digital interventions should allow sufficient scope for personalization and interaction to increase patient engagement and enable benefits from self-care apps. Feedback loops allow the participatory development of tailored interventions. PLAIN LANGUAGE SUMMARY: In this study, we investigated the effectiveness of an app-based self-help intervention. Study participants were either randomly assigned to a group that had access to the app or a group that received access to the app after the end of the study. Although a larger proportion of participants in the intervention group showed a relevant improvement in quality of life, the difference between the two groups was not statistically significant. Less than one-fifth of participants in the intervention group attended at least half of all intervention sessions; patient feedback showed that patients required more personalization and interactive options.

Standardized hierarchical adaptive Lp regression for noise robust focal epilepsy source reconstructions.

OBJECTIVE: To investigate the ability of standardization to reduce source localization errors and measurement noise uncertainties for hierarchical Bayesian algorithms with L1- and L2-norms as priors in electroencephalography and magnetoencephalography of focal epilepsy. METHODS: Description of the standardization methodology relying on the Hierarchical Bayesian framework, referred to as the Standardized Hierarchical Adaptive Lp-norm Regularization (SHALpR). The performance was tested using real data from two focal epilepsy patients. Simulated data that resembled the available real data was constructed for further localization and noise robustness investigation. RESULTS: The proposed algorithms were compared to their non-standardized counterparts, Standardized low-resolution brain electromagnetic tomography, Standardized Shrinking LORETA-FOCUSS, and Dynamic statistical parametric maps. Based on the simulations, the standardized Hierarchical adaptive algorithm using L2-norm was noise robust for 10 dB signal-to-noise ratio (SNR), whereas the L1-norm prior worked robustly also with 5 dB SNR. The accuracy of the standardized L1-normed methodology to localize focal activity was under 1 cm for both patients. CONCLUSIONS: Numerical results of the proposed methodology display improved localization and noise robustness. The proposed methodology also outperformed the compared methods when dealing with real data. SIGNIFICANCE: The proposed standardized methodology, especially when employing the L1-norm, could serve as a valuable assessment tool in surgical decision-making.

Dissociative seizures in the emergency room: room for improvement.

BACKGROUND: Dissociative seizures, also known as functional or psychogenic non-epileptic seizures, account for 11%-27% of all emergency seizure presentations. Misdiagnosis as epileptic seizures is common and leads to ineffective and potentially harmful treatment escalations. We assess the potential for diagnostic improvement at different stages of emergency workup and estimate the utility of benzodiazepines. METHODS: A retrospective study of all emergency presentations with a discharge diagnosis of acute dissociative seizures seen at a university hospital 2010-2022 was performed to assess clinical characteristics and emergency decision-making. RESULTS: Among 156 patients (73% female, median 29 years), 15% presented more than once for a total of 203 presentations. Half of seizures were ongoing at first medical contact; prolonged seizures and clusters were common (23% and 24%). Diagnostic accuracy differed between on-site emergency physicians and emergency department neurologists (12% vs 52%). Typical features such as eye closure, discontinuous course and asynchronous movements were common. Benzodiazepines were given in two-thirds of ongoing seizures, often in high doses and preferentially for major hyperkinetic semiology. Clinical response to benzodiazepines was mixed, with a minority of patients remaining either unaffected (16%) or becoming critically sedated (13%). A quarter of patients given benzodiazepines by emergency medical services were admitted to a monitoring unit, 9% were intubated. CONCLUSIONS: Improved semiological assessment could reduce early misdiagnosis of dissociative seizures. Although some seizures seem to respond to benzodiazepines, critical sedation is common, and further studies are needed to assess the therapeutic ratio.

The relationship of action, affect, and metacognition in functional seizures.

INTRODUCTION: Metacognition provides a lens through which individuals experience, interpret, and respond to their affective states and behavior; it might thus influence complex neuropsychiatric conditions such as functional seizures - events characterized by states of heightened affective arousal and the disinhibition of prepotent behavior. In this pilot study, we aimed to establish a better understanding of the role of metacognition in functional seizures and its relationship to affective arousal and behavioral disinhibition (i.e., problems in suppressing prepared behavior). We hypothesized that affective arousal is related to higher behavioral disinhibition as well as slower reaction times, that affect and action (performing vs. not performing a movement) are related to memory and metacognition, and that metacognition is related to illness characteristics. METHODS: We used a combination of an emotional go/no-go and a metacognitive recognition task with affectively valenced and neutral images in 18 patients with functional seizures. We compared markers of behavioral inhibition as well as indices for memory and metacognitive performance between affective (vs. neutral) and action/go (vs. inhibition/no-go) conditions. RESULTS: Contrary to our hypothesis, behavioral disinhibition was not different between conditions. However, we found slower reaction times for affectively valenced stimuli. Memory performance and metacognition were better for affectively valenced pictures and for pictures used in go trials (i.e., associated with action/performing the movement). Illness factors (illness duration, seizure frequency, levels of self-reported anxiety) were correlated with aspects of metacognition. CONCLUSIONS: This pilot study offers first insights into alterations in metacognition related to action and affect in patients with functional seizures; specifically, that affectively valenced stimuli and active engagement are related to enhanced memory and metacognition. This relationship was also found with respect to illness factors. These results provide insight into potentially underlying pathomechanisms, although the lack of a control group limits evaluating the specificity of these findings.

Validating EEG source imaging using intracranial electrical stimulation.

Electrical source imaging is used in presurgical epilepsy evaluation and in cognitive neurosciences to localize neuronal sources of brain potentials recorded on EEG. This study evaluates the spatial accuracy of electrical source imaging for known sources, using electrical stimulation potentials recorded on simultaneous stereo-EEG and 37-electrode scalp EEG, and identifies factors determining the localization error. In 11 patients undergoing simultaneous stereo-EEG and 37-electrode scalp EEG recordings, sequential series of 99-110 biphasic pulses (2 ms pulse width) were applied by bipolar electrical stimulation on adjacent contacts of implanted stereo-EEG electrodes. The scalp EEG correlates of stimulation potentials were recorded with a sampling rate of 30 kHz. Electrical source imaging of averaged stimulation potentials was calculated utilizing a dipole source model of peak stimulation potentials based on individual four-compartment finite element method head models with various skull conductivities (range from 0.0413 to 0.001 S/m). Fitted dipoles with a goodness of fit of ≥80% were included in the analysis. The localization error was calculated using the Euclidean distance between the estimated dipoles and the centre point of adjacent stimulating contacts. A total of 3619 stimulation locations, respectively, dipole localizations, were included in the evaluation. Mean localization errors ranged from 10.3 to 26 mm, depending on source depth and selected skull conductivity. The mean localization error increased with an increase in source depth (r(3617) = [0.19], P = 0.000) and decreased with an increase in skull conductivity (r(3617) = [-0.26], P = 0.000). High skull conductivities (0.0413-0.0118 S/m) yielded significantly lower localization errors for all source depths. For superficial sources (<20 mm from the inner skull), all skull conductivities yielded insignificantly different localization errors. However, for deeper sources, in particular >40 mm, high skull conductivities of 0.0413 and 0.0206 S/m yielded significantly lower localization errors. In relation to stimulation locations, the majority of estimated dipoles moved outward-forward-downward to inward-forward-downward with a decrease in source depth and an increase in skull conductivity. Multivariate analysis revealed that an increase in source depth, number of skull holes and white matter volume, while a decrease in skull conductivity independently led to higher localization error. This evaluation of electrical source imaging accuracy using artificial patterns with a high signal-to-noise ratio supports its application in presurgical epilepsy evaluation and cognitive neurosciences. In our artificial potential model, optimizing the selected skull conductivity minimized the localization error. Future studies should examine if this accounts for true neural signals.

Teaching distinguishing semiological features improves diagnostic accuracy of seizure-like events by emergency physicians.

BACKGROUND: Misdiagnosis of seizure-like events (SLE) in emergency situations is common. Here, we evaluate whether a single, video-based lesson highlighting distinguishing semiological features can improve the diagnostic accuracy of emergency physicians for epileptic seizures (ES), psychogenic non-epileptic seizures (PNES) and syncopes (SY). METHODS: 40 emergency physicians (24 anesthetists, nine surgeons and seven internal medicine specialists by primary specialty) participated in a prospective trial on the diagnostic accuracy of SLE. They assessed video-displayed SLE at two time points: before and after a lecture on distinguishing semiological features. In the lecture, semiological features were demonstrated using patient videos, some were acted by the instructor in addition. The increase in correct diagnoses and recognition of distinguishing semiological features were analyzed. RESULTS: Before the lesson, 45% of 200 SLE-ratings were correct: 15% of SY (n = 40), 30% of PNES (n = 40), 59% of ES (n = 120, focal to bilateral tonic-clonic seizures (FBTCS) 87.5% (n = 40), focal impaired aware seizures (FIAS) 45% (n = 80)). Semiology teaching increased both the rate of correct diagnoses of SLE to overall 79% (p < 0.001) (ES 91% (p < 0.001), FBCTS 98% (n.s.), FIAS 88% (p < 0.001), PNES 88% (p < 0.001), SY 35% (p < 0.001)), and the number of recognized distinguishing semiological features. We identified several semiological features with high entity specific positive predictive values (> 0.8). CONCLUSIONS: A single 45-min video-based lesson highlighting distinguishing semiological features improves the diagnostic accuracy of ES, PNES and SY by emergency physicians. We expect that including this aspect into the curriculum of emergency physicians will lead to better individual patient treatment in pre-hospital medicine and more appropriate subsequent use of clinical resources.

Brain tumor related epilepsy: pathophysiological approaches and rational management of antiseizure medication.

BACKGROUND: Brain tumor related epilepsy (BTRE) is a common complication of cerebral tumors and its incidence is highly dependent on the type of tumor, ranging from 10-15% in brain metastases to > 80% in low grade gliomas. Clinical management is challenging and has to take into account aspects beyond the treatment of non-tumoral epilepsy. MAIN BODY: Increasing knowledge about the pathophysiology of BTRE, particularly on glutamatergic mechanisms of oncogenesis and epileptogenesis, might influence management of anti-tumor and BTRE treatment in the future. The first seizure implies the diagnosis of epilepsy in patients with brain tumors. Due to the lack of prospective randomized trials in BTRE, general recommendations for focal epilepsies currently apply concerning the initiation of antiseizure medication (ASM). Non-enzyme inducing ASM is preferable. Prospective trials are needed to evaluate, if AMPA inhibitors like perampanel possess anti-tumor effects. ASM withdrawal has to be weighed very carefully against the risk of seizure recurrence, but can be achievable in selected patients. Permission to drive is possible for some patients with BTRE under well-defined conditions, but requires thorough neurological, radiological, ophthalmological and neuropsychological examination. CONCLUSION: An evolving knowledge on pathophysiology of BTRE might influence future therapy. Randomized trials on ASM in BTRE with reliable endpoints are needed. Management of withdrawal of ASMs and permission to drive demands thorough diagnostic as well as neurooncological and epileptological expertise.

German translation and validation of the brief Epilepsy Anxiety Survey Instrument (brEASI).

BACKGROUND: Anxiety disorders remain undiagnosed in routine clinical practice in up to two thirds of affected patients with epilepsy despite their significant impact on medical and psychosocial outcomes. The study objective was to translate and validate the German 8-item "brief Epilepsy Anxiety Survey Instrument" (brEASI) to facilitate effective screening for the presence of anxiety disorders in German-speaking patients. METHODS: After expert translation into German, the brEASI was completed by consecutive adult inpatients with epilepsy hospitalized for seizures at an academic reference epilepsy center. Patients also completed the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), the Generalized Anxiety Disorder scale (GAD-7) for external validity, and underwent a standardized interview (Mini-DIPS-OA) as a gold standard to determine the presence of an ICD-10 anxiety disorder (generalized anxiety disorder (GAD), panic disorder, agoraphobia, and social phobia). Receiver operating characteristics (ROC) were calculated to determine the diagnostic accuracy of the brEASI, including the associated area under the curve (AUC) statistics to determine the potential of the brEASI to identify ICD-10 anxiety disorders diagnosed by interview. For comparative purposes, these analyses were also conducted for the GAD-7. RESULTS: Of 80 recruited adult inpatients with epilepsy, 18 (23 %) were found to have a current anxiety disorder through standardized interview. In this study, both brEASI and GAD-7 showed a better diagnostic performance at a cutoff of >5 than at the previously reported cutoff values of >6 and >9, respectively. The AUC of the German brEASI was outstanding (AUC = 0.90, 95 % confidence interval (CI) = 0.82-0.96) for detecting all anxiety disorders and excellent for detecting non-GAD disorders (AUC = 0.85, CI = 0.76-0.92) at a cutoff of >5. At this optimal cutoff of >5 the brEASI demonstrated better sensitivity and specificity (89 % and 84 %) for identifying anxiety disorders than the GAD-7 (83 % and 74 %). The final German version of the brEASI is free to download at https://www.v-neuro.de/veroeffentlichungen/. CONCLUSION: The German version of the brEASI represents a valid and reliable epilepsy-specific anxiety screening instrument. A positive screening result should be followed by further diagnostic procedures. Appropriate therapeutic steps should be initiated if the presence of an anxiety disorder or other psychiatric disorders is confirmed.

Point-of-Care Testing Using a Neuropsychology Pocketcard Set: A Preliminary Validation Study.

Neurocognitive screening instruments usually require printed sheets and additional accessories, and can be unsuitable for low-threshold use during ward rounds or emergency workup, especially in patients with motor impairments. Here, we test the utility of a newly developed neuropsychology pocketcard set for point-of-care testing. For aphasia and neglect assessment, modified versions of the Language Screening Test and the Bells Test were validated on 63 and 60 acute stroke unit patients, respectively, against expert clinical evaluation and the original pen-and-paper Bells Test. The pocketcard aphasia test achieved an excellent area under the curve (AUC) of 0.94 (95% CI: 0.88−1, p < 0.001). Using an optimal cut-off of ≥2 mistakes, sensitivity was 91% and specificity was 81%. The pocketcard Bells Task, measured against the clinical neglect diagnosis, achieved higher sensitivity (89%) and specificity (88%) than the original paper-based instrument (78% and 75%, respectively). Separately, executive function tests (modified versions of the Trail Making Test [TMT] A and B, custom Stroop color naming task, vigilance 'A' Montreal Cognitive Assessment item) were validated on 44 inpatients with epilepsy against the EpiTrack® test battery. Pocketcard TMT performance was significantly correlated with the original EpiTrack® versions (A: r = 0.64, p < 0.001; B: r = 0.75, p < 0.001). AUCs for the custom Stroop task, TMT A and TMT B for discriminating between normal and pathological EpiTrack® scores were acceptable, excellent and outstanding, respectively. Quick point-of-care testing using a pocketcard set is feasible and yields diagnostically valid information.

Cortical thickness in default mode network hubs correlates with clinical features of dissociative seizures.

BACKGROUND: Dissociative seizures (DS) are a common subtype of functional neurological disorder (FND) with an incompletely understood pathophysiology. Here, gray matter variations and their relationship to clinical features were investigated. METHODS: Forty-eight patients with DS without neurological comorbidities and 43 matched clinical control patients with syncope with structural brain MRIs were identified retrospectively. FreeSurfer-based cortical thickness and FSL FIRST-based subcortical volumes were used for quantitative analyses, and all findings were age and sex adjusted, and corrected for multiple comparisons. RESULTS: Groups were not statistically different in cortical thickness or subcortical volumes. For patients with DS, illness duration was inversely correlated with cortical thickness of left-sided anterior and posterior cortical midline structures (perigenual/dorsal anterior cingulate cortex, superior parietal cortex, precuneus), and clusters at the left temporoparietal junction (supramarginal gyrus, postcentral gyrus, superior temporal gyrus), left postcentral gyrus, and right pericalcarine cortex. Dissociative seizure duration was inversely correlated with cortical thickness in the left perigenual anterior cingulate cortex, superior/middle frontal gyri, precentral gyrus and lateral occipital cortex, along with the right isthmus-cingulate and posterior-cingulate, middle temporal gyrus, and precuneus. Seizure frequency did not show any significant correlations. CONCLUSIONS: In patients with DS, illness duration inversely correlated with cortical thickness of left-sided default mode network cortical hubs, while seizure duration correlated with left frontopolar and right posteromedial areas, among others. Etiological factors contributing to neuroanatomical variations in areas related to self-referential processing in patients with DS require more research inquiry.

Validating EEG, MEG and Combined MEG and EEG Beamforming for an Estimation of the Epileptogenic Zone in Focal Cortical Dysplasia.

MEG and EEG source analysis is frequently used for the presurgical evaluation of pharmacoresistant epilepsy patients. The source localization of the epileptogenic zone depends, among other aspects, on the selected inverse and forward approaches and their respective parameter choices. In this validation study, we compare the standard dipole scanning method with two beamformer approaches for the inverse problem, and we investigate the influence of the covariance estimation method and the strength of regularization on the localization performance for EEG, MEG, and combined EEG and MEG. For forward modelling, we investigate the difference between calibrated six-compartment and standard three-compartment head modelling. In a retrospective study, two patients with focal epilepsy due to focal cortical dysplasia type IIb and seizure freedom following lesionectomy or radiofrequency-guided thermocoagulation (RFTC) used the distance of the localization of interictal epileptic spikes to the resection cavity resp. RFTC lesion as reference for good localization. We found that beamformer localization can be sensitive to the choice of the regularization parameter, which has to be individually optimized. Estimation of the covariance matrix with averaged spike data yielded more robust results across the modalities. MEG was the dominant modality and provided a good localization in one case, while it was EEG for the other. When combining the modalities, the good results of the dominant modality were mostly not spoiled by the weaker modality. For appropriate regularization parameter choices, the beamformer localized better than the standard dipole scan. Compared to the importance of an appropriate regularization, the sensitivity of the localization to the head modelling was smaller, due to similar skull conductivity modelling and the fixed source space without orientation constraint.

Diagnostic challenges in patients with temporal lobe seizures and features of autoimmune limbic encephalitis.

BACKGROUND AND PURPOSE: Consensus criteria for autoimmune limbic encephalitis (ALE) allow for a diagnosis even without neuronal antibodies (Abs), but it remains unclear which clinical features should prompt neuronal Ab screening in temporal lobe epilepsy patients. The aim of the study was to investigate whether patients with temporal lobe seizures associated with additional symptoms or signs of limbic involvement may harbor neuronal Abs, and which clinical features should prompt neuronal Ab screening in these patients. METHODS: We identified 47 patients from a tertiary epilepsy center with mediotemporal lobe seizures and additional features suggestive of limbic involvement, including either memory deficits, psychiatric symptoms, mediotemporal magnetic resonance imaging (MRI) hyperintensities or inflammatory cerebrospinal fluid (CSF). Neuronal Ab testing was carried out at two independent reference laboratories (Bielefeld-Bethel, Germany, and Barcelona, Spain). All brain MRI scans were assessed by two reviewers independently. RESULTS: Temporal lobe seizures were accompanied by memory deficits in 35/46 (76%), psychiatric symptoms in 27/42 (64%), and both in 19/42 patients (45%). Limbic T2/fluid-attenuated inversion recovery signal hyperintensities were found in 26/46 patients (57%; unilateral: n = 22, bilateral: n = 4). Standard CSF studies were abnormal in 2/37 patients (5%). Neuronal Abs were confirmed in serum and/or CSF in 8/47 patients (17%) and were directed against neuronal cell-surface targets (leucine-rich glioma inactivated protein 1: n = 1, contactin-associated protein-2: n = 1, undetermined target: n = 3) or glutamic acid decarboxylase in its 65-kD isoform (n = 3, all with high titers). Compared to Ab-negative patients, those who harbored neuronal Abs were more likely to have uni- or bilateral mediotemporal MRI changes (8/8, 100% vs. 18/38, 47%; p = 0.01, Fisher's exact test). CONCLUSIONS: In patients with temporal lobe seizures and additional limbic signs, 17% had neuronal Abs affirming ALE diagnosis. Mediotemporal MRI changes were found in all Ab-positive cases and had a positive likelihood ratio of 2.11 (95% confidence interval 1.51-2.95).

Enhancing Safety in Epilepsy Surgery (EASINESS): Study Protocol for a Retrospective, Multicenter, Open Registry.

Introduction: Optimizing patient safety and quality improvement is increasingly important in surgery. Benchmarks and clinical quality registries are being developed to assess the best achievable results for several surgical procedures and reduce unwarranted variation between different centers. However, there is no clinical database from international centers for establishing standardized reference values of patients undergoing surgery for mesial temporal lobe epilepsy. Design: The Enhancing Safety in Epilepsy Surgery (EASINESS) study is a retrospectively conducted, multicenter, open registry. All patients undergoing mesial temporal lobe epilepsy surgery in participating centers between January 2015 and December 2019 are included in this study. The patient characteristics, preoperative diagnostic tools, surgical data, postoperative complications, and long-term seizure outcomes are recorded. Outcomes: The collected data will be used for establishing standardized reference values ("benchmarks") for this type of surgical procedure. The primary endpoints include seizure outcomes according to the International League Against Epilepsy (ILAE) classification and defined postoperative complications. Discussion: The EASINESS will define robust and standardized outcome references after amygdalohippocampectomy for temporal lobe epilepsy. After the successful definition of benchmarks from an international cohort of renowned centers, these data will serve as reference values for the evaluation of novel surgical techniques and comparisons among centers for future clinical trials. Clinical trial registration: This study is indexed at clinicaltrials.gov (NT 04952298).

Screening for Psychiatric Comorbidities and Psychotherapeutic Assessment in Inpatient Epilepsy Care: Preliminary Results of an Implementation Study.

Background: Anxiety and depression remain underdiagnosed in routine clinical practice in up to two thirds of epilepsy patients despite significant impact on medical and psychosocial outcome. Barriers to adequate mental health care for epilepsy and/or psychogenic non-epileptic seizures (PNES) include a lack of integrated mental health specialists and standardized procedures. This naturalistic study outlines the procedures and outcome of a recently established psychotherapeutic service. Methods: Routine screening included the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E, cut-off value > 13) and Generalized Anxiety Disorder scale (GAD-7, cut-off value > 5). Positively (above cut-off in at least one questionnaire) screened patients were seen for a standardized interview for mental health disorders and the development of a personalized treatment plan. PNES patients were seen irrespective of their screening score. Resources were provided to support self-help and access to psychotherapy. Patients were contacted 1 month after discharge to evaluate adherence to therapeutic recommendations. Results: 120 patients were screened. Overall, 56 of 77 positively screened patients (77%) were found to have a psychiatric diagnosis through standardized interview. More epilepsy patients with an anxiety disorder had previously been undiagnosed compared to those with a depressive episode (63% vs. 30%); 24 epilepsy patients (62%) with a psychiatric comorbidity and 10 PNES patients (59%) were not receiving any mental health care. At follow-up, 16/17 (94%) epilepsy patients and 7/7 PNES patients without prior psychiatric treatment were adhering to therapeutic recommendations. Conclusion: Integrating mental health specialists and establishing standardized screening and follow-up procedures improve adherence to mental health care recommendations in epilepsy and PNES patients.

Factors influencing the detection of treatable epileptogenic lesions on MRI. A randomized prospective study.

BACKGROUND: To prospectively analyze factors associated with detecting epileptogenic lesions on MRI within the work-sharing process of neurologists, epileptologists, radiologists and neuroradiologists. METHODS: We assembled four sets of six MRI scans, each set representing five typical epileptogenic lesions (hippocampal sclerosis or limbic encephalitis; focal cortical dysplasias; periventricular nodular or other heterotopias; long-term epilepsy associated tumors; gliotic scar, hemosiderin or cavernoma), and non - lesional epilepsy. At professional conferences, we invited neurologists, epileptologists, radiologists, and neuroradiologists to read two out of four MRI sets, one of which was presented with a clinical focus hypothesis. Participants were randomly assigned to MRI sets. Effects of examiners' specialty, duration of training and professional experience on detection rate of epileptogenic lesions were investigated. RESULTS: Fourty-eight neurologists, 22 epileptologists, 20 radiologists and 21 neuroradiologists read 1323 MRI scans. Overall, 613 of 1101 (55.7%) epileptogenic lesions were detected. Long-term epilepsy associated tumors (182/221, 82.4%) were found more frequently than gliotic scar, hemosiderin or cavernoma (157/220, 71.4%), hippocampal sclerosis or limbic encephalitis (141/220, 64.1%), nodular heterotopia (68/220, 30.9%) and focal cortical dysplasias (65/220, 29.5%, p < 0.001). Provision of a focus hypothesis improved the detection of hippocampal sclerosis or limbic encephalitis (86/110, 78.2% vs 55/110, 50%, p < 0.001) and focal cortical dysplasias (40/110, 36.4% vs 25/110, 22.7%, p = 0.037). Neuroradiologists and epileptologists were more likely than radiologists and neurologists to be amongst the most successful readers. In multivariable analysis, type of epileptogenic lesion, specialty of MRI reader, and provision of focus hypothesis predicted correct identification of epileptogenic lesions. CONCLUSIONS: Epileptogenic lesions are often not recognized on MRI even by expert readers. Their detection can be improved by providing a focus hypothesis. These results stress the need for training in the MRI characteristics of epilepsy - specific pathology, and, most importantly, interdisciplinary communication between neurologists/epileptologists and (neuro)radiologists to improve detection of epileptogenic lesions.

External validation of automated focal cortical dysplasia detection using morphometric analysis.

OBJECTIVE: Focal cortical dysplasias (FCDs) are a common cause of drug-resistant focal epilepsy but frequently remain undetected by conventional magnetic resonance imaging (MRI) assessment. The visual detection can be facilitated by morphometric analysis of T1-weighted images, for example, using the Morphometric Analysis Program (v2018; MAP18), which was introduced in 2005, independently validated for its clinical benefits, and successfully integrated in standard presurgical workflows of numerous epilepsy centers worldwide. Here we aimed to develop an artificial neural network (ANN) classifier for robust automated detection of FCDs based on these morphometric maps and probe its generalization performance in a large, independent data set. METHODS: In this retrospective study, we created a feed-forward ANN for FCD detection based on the morphometric output maps of MAP18. The ANN was trained and cross-validated on 113 patients (62 female, mean age ± SD =29.5 ± 13.6 years) with manually segmented FCDs and 362 healthy controls (161 female, mean age ± SD =30.2 ± 9.6 years) acquired on 13 different scanners. In addition, we validated the performance of the trained ANN on an independent, unseen data set of 60 FCD patients (28 female, mean age ± SD =30 ± 15.26 years) and 70 healthy controls (42 females, mean age ± SD = 40.0 ± 12.54 years). RESULTS: In the cross-validation, the ANN achieved a sensitivity of 87.4% at a specificity of 85.4% on the training data set. On the independent validation data set, our method still reached a sensitivity of 81.0% at a comparably high specificity of 84.3%. SIGNIFICANCE: Our method shows a robust automated detection of FCDs and performance generalizability, largely independent of scanning site or MR-sequence parameters. Taken together with the minimal input requirements of a standard T1 image, our approach constitutes a clinically viable and useful tool in the presurgical diagnostic routine for drug-resistant focal epilepsy.

Microstructural integrity of affective neurocircuitry in patients with dissociative seizures is associated with emotional task performance, illness severity and trauma history.

PURPOSE: To identify variations in white matter tract integrity related to behavioural control in response to emotional stimuli in patients with dissociative seizures (DS) and healthy controls (HC), and examine associations with illness characteristics and psychological trauma history. METHODS: Twenty DS patients and 20 HC completed an emotional go/no-go task and questionnaires, and then underwent diffusion tensor imaging (DTI). RESULTS: Patients had higher false alarm rates in response to negative emotional stimuli than HC. Task performance was correlated with self-reported difficulties in emotional awareness and regulation in everyday life. White matter analysis using tract-based spatial statistics revealed no between-group differences. In patients, fractional anisotropy (FA) in the right uncinate fasciculus, right and left fornix/stria terminalis, and corpus callosum were correlated with task performance. Similar results were found for radial diffusivity (RD), but not mean (MD) or axial diffusivity (AD). In HC, task performance was associated with AD and RD of fewer and smaller clusters in the corpus callosum and right fornix/stria terminalis, and none for FA or MD. Probabilistic tractography of thus identified tracts revealed that mean FA values were correlated with illness parameters (right fornix/stria terminalis with age at onset; posterior corpus callosum with seizure frequency), and psychological trauma history (traumatic experiences during adolescence with anterior corpus callosum). CONCLUSIONS: Patients with DS show impaired behavioural control in response to emotional stimuli. Microstructural variations in task-related neurocircuitry show associations with illness parameters and psychological trauma history. Future studies using psychiatric controls should examine the specificity of these findings.

SpikeDeep-classifier: a deep-learning based fully automatic offline spike sorting algorithm.

Objective.Advancements in electrode design have resulted in micro-electrode arrays with hundreds of channels for single cell recordings. In the resulting electrophysiological recordings, each implanted electrode can record spike activity (SA) of one or more neurons along with background activity (BA). The aim of this study is to isolate SA of each neural source. This process is called spike sorting or spike classification. Advanced spike sorting algorithms are time consuming because of the human intervention at various stages of the pipeline. Current approaches lack generalization because the values of hyperparameters are not fixed, even for multiple recording sessions of the same subject. In this study, a fully automatic spike sorting algorithm called 'SpikeDeep-Classifier' is proposed. The values of hyperparameters remain fixed for all the evaluation data.Approach.The proposed approach is based on our previous study (SpikeDeeptector) and a novel background activity rejector (BAR), which are both supervised learning algorithms and an unsupervised learning algorithm (K-means). SpikeDeeptector and BAR are used to extract meaningful channels and remove BA from the extracted meaningful channels, respectively. The process of clustering becomes straight-forward once the BA is completely removed from the data. Then, K-means with a predefined maximum number of clusters is applied on the remaining data originating from neural sources only. Lastly, a similarity-based criterion and a threshold are used to keep distinct clusters and merge similar looking clusters. The proposed approach is called cluster accept or merge (CAOM) and it has only two hyperparameters (maximum number of clusters and similarity threshold) which are kept fixed for all the evaluation data after tuning.Main results.We compared the results of our algorithm with ground-truth labels. The algorithm is evaluated on data of human patients and publicly available labeled non-human primates (NHPs) datasets. The average accuracy of BAR on datasets of human patients is 92.3% which is further reduced to 88.03% after (K-means + CAOM). In addition, the average accuracy of BAR on a publicly available labeled dataset of NHPs is 95.40% which reduces to 86.95% after (K-mean + CAOM). Lastly, we compared the performance of the SpikeDeep-Classifier with two human experts, where SpikeDeep-Classifier has produced comparable results.Significance.The SpikeDeep-Classifier is evaluated on the datasets of multiple recording sessions of different species, different brain areas and different electrode types without further retraining. The results demonstrate that 'SpikeDeep-Classifier' possesses the ability to generalize well on a versatile dataset and henceforth provides a generalized and fully automated solution to offline spike sorting.Clinical trial registration numberThe clinical trial registration number for patients implanted with the Utah array isNCT 01849822.For the epilepsy patients, approval from the local ethics committee at the Ruhr-University Bochum, Germany, was obtained prior to implantation. The Clinical trial registration number for the epilepsy patients implanted with microwires is16-5670.

Suggestive seizure induction for inpatients with suspected psychogenic nonepileptic seizures.

OBJECTIVE: To determine the utility of suggestive seizure induction for inpatient work-up of suspected psychogenic nonepileptic seizures (PNES). METHODS: Prospective study of epilepsy center inpatient admissions with suspected PNES. Patients were randomized to undergo suggestive induction first (group A) and then, if necessary, long-term video-electroencephalography (EEG) monitoring, or vice versa (group B). Diagnostic pathways were compared. Potential clinical predictors for diagnostic success were evaluated. RESULTS: Length of in-hospital stay did not significantly differ between groups. Suspicion of PNES was confirmed in 43 of 77 (56%) patients, evenly distributed between group A (22 of 39) and group B (21 of 38). In nine patients, recorded habitual seizures were epileptic and in 25 cases, no diagnostic event could be recorded. Diagnosis of PNES was ascertained primarily by recording a typical seizure through suggestive induction in 24 patients and through long-term monitoring in 19 patients. In group A (induction first), monitoring was not deemed necessary in 21% of cases. In group B (monitoring first), 13% would have remained inconclusive without suggestive induction. Patients who reported triggers to their habitual seizures were not more likely to have spontaneous or provoked PNES during monitoring or suggestive inducion, respectively. Patients with subjective seizure prodromes (auras) were significantly more likely to have a PNES during suggestive induction than those without (odds ratio [OR] 3.4, 95% confidence interval [CI] 1.1-10.4). There was no significant difference in seizure frequency between patients with spontaneous PNES during long-term monitoring and those with nondiagnostic monitoring sessions. SIGNIFICANCE: Our results support the notion that suggestive seizure induction can reduce the number of inconclusive inpatient workups, and can obviate resource-intensive long-term monitoring in one fifth of cases. Patients who are aware of prodromes might have a higher chance of having seizures induced through suggestion.