Could the 2017 ILAE and the four-dimensional epilepsy classifications be merged to a new "Integrated Epilepsy Classification"?

Autoimmune-associated epilepsy - a challenging concept

The current International League Against Epilepsy (ILAE) definition and classification guidelines for the first time introduced the category of immune-mediated focal epilepsy in addition to structural, genetic, infectious, and metabolic aetiologies. Moreover, the ILAE Autoimmunity and Inflammation Taskforce recently provided a conceptual framework for the distinction between acute "provoked" seizures in the acute phase of autoimmune encephalitis from chronic "unprovoked" seizures due to autoimmune-associated epilepsy. The first category predominately applies to those autoimmune encephalitis patients with autoantibodies against cell surface neural antigens, in whom autoantibodies are assumed to exert a direct ictogenic effect without overt structural damage. These patients do not exhibit enduring predisposition to seizures after the "acute phase" encephalitis, and thus do not fulfil the definition of epilepsy. The second category applies to those autoimmune encephalitis patients with autoantibodies against intracellular neural antigens and Rasmussen's encephalitis, in whom T cells are assumed to cause epileptogenic effects through immune-inflammation and overt structural damage. These patients do exhibit enduring predisposition to seizures after the "acute phase" of encephalitis and thus fulfil the definition of epilepsy. AAE may result from both, ongoing brain autoimmunity and associated structural brain damage according to the current ILAE definition and classification guideline. We here discuss the difficulties of this concept and suggest an unbiased translationally validated and data-driven approach to predict in an individual encephalitis patient the propensity to develop (or not) AAE and the cognitive and behavioural outcome.

Lateralization of delta band power in magnetoencephalography (MEG) in patients with unilateral focal epilepsy and its relation to verbal fluency

INTRODUCTION

Delta power is a clinically established biomarker for abnormal brain processes. However, in patients with unilateral focal epilepsy (FE) it is still not well understood, how it relates to the epileptogenic zone and to neurocognitive functioning. The aim of the present study was thus to assess how delta power relates to the affected hemisphere, whether lateralization strength differs between the patients, and how changes in delta power correlate with cognitive functioning.

METHOD

We retrospectively studied patients with left (LFE) and right FE (RFE) who had undergone a resting-state magnetoencephalography measurement. We computed global and hemispheric delta power and lateralization indices and examined whether delta power correlates with semantic and letter verbal fluency (former being a marker for language and verbal memory, latter for executive functions) in 26 FE patients (15 LFE, 11 RFE) and 10 healthy controls.

RESULTS

Delta power was increased in FE patients compared to healthy controls. However, the increase across hemispheres was related to the site of the epileptic focus: On group level, LFE patients showed higher delta power in both hemispheres, whereas RFE patients primarily exhibited higher delta power in the ipsilateral right hemisphere. Both groups showed co-fluctuations of delta power between the hemispheres. Besides, delta power correlated negatively only with letter verbal fluency.

CONCLUSION

The findings confirm and provide further evidence that delta power is a marker of pathological activity and abnormal brain processes in FE. Delta power dynamics differ between patient groups, indicating that delta power could offer additional diagnostic value. The negative association of delta power and letter verbal fluency suggests that executive dysfunctions are related to low frequency abnormalities.

One Patient, Three Providers: A Multidisciplinary Approach to Managing Common Neuropsychiatric Cases

BACKGROUND

Neuropsychiatric cases require a multidisciplinary approach for effective management. This paper presented case-based discussions on migraine, dementia, epilepsy, mood disorders, neuralgia, and psychosis from the perspectives of a family physician, neurologist, and psychiatrist. The goal was to highlight the importance of collaboration between healthcare providers in managing these complex cases.

METHODS

The paper was based on the proceedings of the Mediterranean Neuropsychiatry Symposium, where experts from family medicine, neurology, and psychiatry came together for comprehensive case-based discussions. The CARE framework (Case Report, Appraisal, Research, and Education) was developed to guide reporting and evaluation of case reports in clinical practice.

RESULTS

Six cases were presented and discussed, highlighting the importance of a multidisciplinary approach in managing neuropsychiatric cases. The cases included chronic migraine with medication overuse, memory dysfunction with language and behavioral problems, refractory epileptic seizures with subjective sensory symptoms, bipolar affective disorder with normal pressure hydrocephalus, postherpetic neuralgia in a case with bipolar affective disorder, and psychosis with recurrent attacks with the abuse of several substances.

CONCLUSION

A biopsychosocial multidisciplinary approach is essential for managing neuropsychiatric cases effectively on behalf of the patients and public health of the country. The CARE framework can guide the reporting and evaluation of case reports in clinical practice, ensuring that patients receive comprehensive and effective care. Healthcare providers should collaborate to provide the best possible care for patients with complex and multifaceted needs.

Ontology-based feature engineering in machine learning workflows for heterogeneous epilepsy patient records

Biomedical ontologies are widely used to harmonize heterogeneous data and integrate large volumes of clinical data from multiple sources. This study analyzed the utility of ontologies beyond their traditional roles, that is, in addressing a challenging and currently underserved field of feature engineering in machine learning workflows. Machine learning workflows are being increasingly used to analyze medical records with heterogeneous phenotypic, genotypic, and related medical terms to improve patient care. We performed a retrospective study using neuropathology reports from the German Neuropathology Reference Center for Epilepsy Surgery at Erlangen, Germany. This cohort included 312 patients who underwent epilepsy surgery and were labeled with one or more diagnoses, including dual pathology, hippocampal sclerosis, malformation of cortical dysplasia, tumor, encephalitis, and gliosis. We modeled the diagnosis terms together with their microscopy, immunohistochemistry, anatomy, etiologies, and imaging findings using the description logic-based Web Ontology Language (OWL) in the Epilepsy and Seizure Ontology (EpSO). Three tree-based machine learning models were used to classify the neuropathology reports into one or more diagnosis classes with and without ontology-based feature engineering. We used five-fold cross validation to avoid overfitting with a fixed number of repetitions while leaving out one subset of data for testing, and we used recall, balanced accuracy, and hamming loss as performance metrics for the multi-label classification task. The epilepsy ontology-based feature engineering approach improved the performance of all the three learning models with an improvement of 35.7%, 54.5%, and 33.3% in logistics regression, random forest, and gradient tree boosting models respectively. The run time performance of all three models improved significantly with ontology-based feature engineering with gradient tree boosting model showing a 93.8% reduction in the time required for training and testing of the model. Although, all three models showed an overall improved performance across the three-performance metrics using ontology-based feature engineering, the rate of improvement was not consistent across all input features. To analyze this variation in performance, we computed feature importance scores and found that microscopy had the highest importance score across the three models, followed by imaging, immunohistochemistry, and anatomy in a decreasing order of importance scores. This study showed that ontologies have an important role in feature engineering to make heterogeneous clinical data accessible to machine learning models and also improve the performance of machine learning models in multilabel multiclass classification tasks.

Seizures and Epilepsy in Childhood

PURPOSE OF REVIEW

This article highlights basic concepts of seizures and epilepsy in pediatric patients, as well as basic treatment principles for this age group.

RECENT FINDINGS

Epilepsy is the most common neurologic disorder in childhood. Accurate diagnosis is key; in older children, epileptic seizures need to be differentiated from various paroxysmal nonepileptic events, whereas in neonates, the majority of seizures are subclinical (electroencephalographic). Antiseizure medications remain the first-line treatment, but ketogenic diet and epilepsy surgery have also shown positive outcomes and can decrease drug burden. Genetic causes account for approximately 30% of cases, and the recognition of electroclinical syndromes is being replaced by the concept of genetic spectrums. Precision medicine therapies are promising, but wide application in daily practice still has a long way to go. Early access to specialist centers and optimal treatments positively affects prognosis and future neurodevelopment.

SUMMARY

Although novel findings from all fields of research are being incorporated into everyday clinical practice, a better quality of life for children with seizures and epilepsy and their families is the ultimate priority.

Executive deficits in neuropsychological testing differentiate between autoimmune temporal lobe epilepsy caused by limbic encephalitis and temporal lobe epilepsies with non-autoimmune etiologies

OBJECTIVE

Patients with temporal lobe epilepsy caused by autoimmune limbic encephalitis (AI-TLE) clinically resemble patients with temporal lobe epilepsy with non-autoimmune etiologies (NAI-TLE) but have a different prognosis and require specific adjusted therapies. The objective of this study was to investigate whether patients with these forms of TLE can be discerned by means of neuropsychological assessment.

METHODS

Data from 103 patients with TLE (n = 39 with AI-TLE and n = 64 with NAI-TLE, including n = 39 with hippocampal sclerosis [HS] and n = 25 with low-grade epilepsy-associated tumors [LEAT]) and 25 healthy controls who underwent comprehensive neuropsychological assessments were analyzed retrospectively. The neuropsychological characteristics (mean z-scores) were compared between groups using one-way ANOVA, independent-samples t-tests, and discriminant function analysis (DFA).

RESULTS

The groups of patients with TLE showed significantly lower performance in attentional, visuospatial, verbal memory, and nonverbal memory functions compared to the healthy controls. Solely in the domain of executive functions, patients with AI-TLE showed significantly lower performance compared to patients with NAI-TLE regarding cognitive flexibility (p = 0.002) and verbal fluency (p = 0.018). Moreover, the DFA identified cognitive flexibility to be most appropriate to differentiate between patients with AI-TLE and patients with HS. Group membership was correctly predicted through neuropsychological assessment alone in 66.7% of the patients using cross-validation.

SIGNIFICANCE

We were able to identify specific neuropsychological features in our sample of patients with AI-TLE. While all groups of patients with TLE showed the expected TLE-typical memory impairments, significant differences between patients with AI-TLE and NAI-TLE were present only in the cognitive domain of executive functions. This finding facilitates the choice of suitable psychometric tests in clinical routine and, thus, the clinical differential diagnosis between these entities.

Wada test results contribute to the prediction of change in verbal learning and verbal memory function after temporal lobe epilepsy surgery

In recent years, the clinical usefulness of the Wada test (WT) has been debated among researchers in the field. Therefore, we aimed to assess its contribution to the prediction of change in verbal learning and verbal memory function after epilepsy surgery. Data from 56 patients with temporal lobe epilepsy who underwent WT and subsequent surgery were analyzed retrospectively. Additionally, a standard neuropsychological assessment evaluating attentional, learning and memory, visuospatial, language, and executive function was performed both before and 12 months after surgery. Hierarchical linear regression analyses were used to determine the incremental value of WT results over socio-demographic, clinical, and neuropsychological characteristics in predicting postsurgical change in patients' verbal learning and verbal memory function. The incorporation of WT results significantly improved the prediction models of postsurgical change in verbal learning (∆R² = 0.233, p = .032) and verbal memory function (∆R² = 0.386, p = .005). Presurgical performance and WT scores accounted for 41.8% of the variance in postsurgical change in verbal learning function, and 51.1% of the variance in postsurgical change in verbal memory function. Our findings confirm that WT results are of significant incremental value for the prediction of postsurgical change in verbal learning and verbal memory function. Thus, the WT contributes to determining the risks of epilepsy surgery and, therefore, remains an important part of the presurgical work-up of selected patients with clear clinical indications.

Modeling seizures in the Human Phenotype Ontology according to contemporary ILAE concepts makes big phenotypic data tractable

Objective:

The clinical features of epilepsy determine how it is defined, which in turn guides management. Therefore, consideration of the fundamental clinical entities that comprise an epilepsy is essential in the study of causes, trajectories, and treatment responses. The Human Phenotype Ontology (HPO) is used widely in clinical and research genetics for concise communication and modeling of clinical features, allowing extracted data to be harmonized using logical inference. We sought to redesign the HPO seizure subontology to improve its consistency with current epileptological concepts, supporting the use of large clinical data sets in high-throughput clinical and research genomics.

Methods:

We created a new HPO seizure subontology based on the 2017 International League Against Epilepsy (ILAE) Operational Classification of Seizure Types, and integrated concepts of status epilepticus, febrile, reflex, and neonatal seizures at different levels of detail. We compared the HPO seizure subontology prior to, and following, our revision, according to the information that could be inferred about the seizures of 791 individuals from three independent cohorts: 2 previously published and 150 newly recruited individuals. Each cohort’s data were provided in a different format and harmonized using the two versions of the HPO.

Results:

The new seizure subontology increased the number of descriptive concepts for seizures 5-fold. The number of seizure descriptors that could be annotated to the cohort increased by 40% and the total amount of information about individuals’ seizures increased by 38%. The most important qualitative difference was the relationship of focal to bilateral tonic-clonic seizure to generalized-onset and focal-onset seizures.

Valproate but not levetiracetam slows the EEG alpha peak frequency - A pharmaco-EEG study

OBJECTIVE

Studies of the effect of valproate (VPA) on the background EEG have shown varying results. Therefore, we compared the effect of VPA and levetiracetam (LEV) on the EEG alpha peak frequency (APF).

METHODS

We retrospectively examined the APF in resting-state EEG of patients undergoing inpatient video-EEG monitoring (VEM) during withdrawal of VPA or LEV. We assessed APF trends by computing linear fits across individual patients' APF as a function of consecutive days, and correlated the APF and daily antiseizure medication (ASM) doses on a single-patient and group level.

RESULTS

The APF in the VPA-group significantly increased over days with falling VPA doses (p = 0.005, n = 13), but did not change significantly in the LEV-group (p = 0.47, n = 18). APF correlated negatively with daily ASM doses in the VPA-group (average of r = -0.74 ± 0.12 across patients, p = 0.0039), but not in the LEV-group (average of r = -0.17 ± 0.18 across patients, p = 0.4072).

CONCLUSIONS

Our results suggest that VPA treatment slows the APF. This APF reduction correlates with the daily dose of VPA and is not present in LEV treatment.

SIGNIFICANCE

Our study identifies a VPA-related slowing of the APF even in patients without electroencephalographic or overt clinical signs of encephalopathy.

Advantages of methohexital over amobarbital in determining hemispheric language and memory lateralization in the Wada test - A retrospective study

OBJECTIVE

Due to supply shortage, amobarbital, the traditional anesthetic agent in Wada testing, was replaced by methohexital in many epilepsy centers. This study aimed to compare the two barbiturates to identify possible advantages or disadvantages of methohexital as compared to amobarbital with regard to the adequacy of language and memory testing during the Wada test.

METHODS

Data from 75 patients with temporal lobe epilepsy who underwent bilateral Wada tests using either amobarbital (n = 53) or methohexital (n = 22) as part of presurgical work-up were analyzed retrospectively. The two subgroups were compared regarding hemispheric language and memory lateralization results and Wada testing characteristics, and the adequacy of language and memory testing was assessed.

RESULTS

We observed shorter durations of motor-, speech-, and EEG recovery after each injection in patients receiving methohexital compared to amobarbital. In addition, significantly more items could be presented during effective hemispheric inactivation in the methohexital group. Moreover, significant correlations of Wada memory scores with standard neuropsychological memory test scores could be found in the methohexital group.

SIGNIFICANCE

Our findings confirm that methohexital is not only equally suitable for Wada testing but has several advantages over amobarbital. Wada testing can be performed more efficiently and under more constant hemispheric inactivation using methohexital. Furthermore, the adequacy of language and memory testing during the Wada test might be affected by the anesthetic agent used.

SARS-CoV-2-related rapid reorganization of an epilepsy outpatient clinic from personal appointments to telemedicine services: A German single-center experience

INTRODUCTION

When the SARS-CoV-2 pandemic reached Europe in 2020, a German governmental order forced clinics to immediately suspend elective care, causing a problem for patients with chronic illnesses such as epilepsy. Here, we report the experience of one clinic that converted its outpatient care from personal appointments to telemedicine services.

METHODS

Documentations of telephone contacts and telemedicine consultations at the Epilepsy Center Frankfurt Rhine-Main were recorded in detail between March and May 2020 and analyzed for acceptance, feasibility, and satisfaction of the conversion from personal to telemedicine appointments from both patients' and medical professionals' perspectives.

RESULTS

Telephone contacts for 272 patients (mean age: 38.7 years, range: 17-79 years, 55.5% female) were analyzed. Patient-rated medical needs were either very urgent (6.6%, n = 18), urgent (23.5%, n = 64), less urgent (29.8%, n = 81), or nonurgent (39.3%, n = 107). Outpatient service cancelations resulted in a lack of understanding (9.6%, n = 26) or anger and aggression (2.9%, n = 8) in a minority of patients, while 88.6% (n = 241) reacted with understanding, or relief (3.3%, n = 9). Telemedicine consultations rather than a postponed face-to-face visit were requested by 109 patients (40.1%), and these requests were significantly associated with subjective threat by SARS-CoV-2 (p = 0.004), urgent or very urgent medical needs (p = 0.004), and female gender (p = 0.024). Telemedicine satisfaction by patients and physicians was high. Overall, 9.2% (n = 10) of patients reported general supply problems due to SARS-CoV-2, and 28.4% (n = 31) reported epilepsy-specific problems, most frequently related to prescriptions, or supply problems for antiseizure drugs (ASDs; 22.9%, n = 25).

CONCLUSION

Understanding and acceptance of elective ambulatory visit cancelations and the conversion to telemedicine consultations was high during the coronavirus disease 2019 (COVID-19) lockdown. Patients who engaged in telemedicine consultations were highly satisfied, supporting the feasibility and potential of telemedicine during the COVID-19 pandemic and beyond.

Assessing Cognitive Change and Quality of Life 12 Months After Epilepsy Surgery-Development and Application of Reliable Change Indices and Standardized Regression-Based Change Norms for a Neuropsychological Test Battery in the German Language

Objective

The establishment of patient-centered measures capable of empirically determining meaningful cognitive change after surgery can significantly improve the medical care of epilepsy patients. Thus, this study aimed to develop reliable change indices (RCIs) and standardized regression-based (SRB) change norms for a comprehensive neuropsychological test battery in the German language.

Methods

Forty-seven consecutive patients with temporal lobe epilepsy underwent neuropsychological assessments, both before and 12 months after surgery. Practice-effect-adjusted RCIs and SRB change norms for each test score were computed. To assess their usefulness, the presented methods were applied to a clinical sample, and binary logistic regression analyses were conducted to model the odds of achieving improvement in quality of life (QOL) after surgery.

Results

The determined RCIs at 90% confidence intervals and the SRB equations for each test score included in the test battery are provided. Cohen’s kappa analyses revealed a moderate mean agreement between the two measures, varying from slight to almost perfect agreement across test scores. Using these measures, a negative association between improvement in QOL and decline in verbal memory functions after surgery was detected (adjusted odds ratio = 0.09, p = 0.006).

Significance

To the best of our knowledge, this study is the first to develop RCIs and SRB change norms necessary for the objective determination of neuropsychological change in a comprehensive test battery in the German language, facilitating the individual monitoring of improvement and decline in each patients’ cognitive functioning and psychosocial situations after epilepsy surgery. The application of the described measures revealed a strong negative association between improvement in QOL and decline in verbal memory functions after surgery.

Risk incidence of fractures and injuries: a multicenter video-EEG study of 626 generalized convulsive seizures

OBJECTIVE

To evaluate the incidence and risk factors of generalized convulsive seizure (GCS)-related fractures and injuries during video-EEG monitoring.

METHODS

We analyzed all GCSs in patients undergoing video-EEG-monitoring between 2007 and 2019 at epilepsy centers in Frankfurt and Marburg in relation to injuries, falls and accidents associated with GCSs. Data were gathered using video material, EEG material, and a standardized reporting form.

RESULTS

A total of 626 GCSs from 411 patients (mean age: 33.6 years; range 3-74 years; 45.0% female) were analyzed. Severe adverse events (SAEs) such as fractures, joint luxation, corneal erosion, and teeth loosening were observed in 13 patients resulting in a risk of 2.1% per GCS (95% CI 1.2-3.4%) and 3.2% per patient (95% CI 1.8-5.2%). Except for a nasal fracture due to a fall onto the face, no SAEs were caused by falls, and all occurred in patients lying in bed without evidence of external trauma. In seven patients, vertebral body compression fractures were confirmed by imaging. This resulted in a risk of 1.1% per GCS (95% CI 0.5-2.2%) and 1.7% per patient (95% CI 0.8-3.3%). These fractures occurred within the tonic phase of a GCS and were accompanied by a characteristic cracking noise. All affected patients reported back pain spontaneously, and an increase in pain on percussion of the affected spine section.

CONCLUSIONS

GCSs are associated with a substantial risk of fractures and shoulder dislocations that are not associated with falls. GCSs accompanied by audible cracking, and resulting in back pain, should prompt clinical and imaging evaluations.

Towards a pragmatic epilepsy classification: Future considerations

The Integrated Epilepsy Classification was recently proposed to merge the 2017 International League Against Epilepsy classification and the four-dimensional epilepsy classification updated in 2019. The efforts in developing the concept of an Integrated Epilepsy Classification scheme are encouraging. However, consideration of brain age, validation in contexts that differ in socioeconomic status and with poor healthcare infrastructure, and incorporation of a team-based approach are necessary. These advancements allow for better clinical management of people with epilepsy and empower people with epilepsy globally.