Adverse cognitive effects of antiepileptic pharmacotherapy: Each additional drug matters

Neuropsychology of late-onset epilepsies

In an increasingly ageing society, patients ageing with epilepsy and those with late-onset epilepsies (LOE) represent a challenge for epilepsy care and treatment. Senescence itself bears risks of pathologies which in the form of acute focal damage (e.g. stroke) or slowly progressive degenerative damage can cause seizures and substantial cognitive impairment. There is converging evidence from studies in LOE that cognitive impairments are present from epilepsy onset before treatment is initiated and may even precede the emergence of seizures. This suggests that these impairments (like the seizures) are expressions of the underlying disease. Indeed, both seizures and cognitive impairments can be early indicators of disease conditions which lead to mental decline. Cognitive decline over time poses the challenge of disentangling the interrelation between seizures, treatment effects and underlying disease. This issue must be considered as some of the etiologies for causing neuropsychological decline can be addressed. Medication and active epilepsy can contribute to impairments and their impact may be reversible. Dementia is rare if seizures are what has brought the person to attention, and if this is not accompanied by other slowly developing features (such as cognitive of psychiatric changes). From a neuropsychological point of view choosing the right screening tools or assessments, obtaining the history and timeline of impairments in relation to epilepsy, and most importantly longitudinally following the patients regardless of whether epilepsy is ultimately controlled or not appear essential.

Health-Related Quality of Life and Cognitive Performance During 12-Month Adjunctive Brivaracetam Treatment in Patients with Focal-Onset Seizures: A Prospective, Observational Study in Europe

INTRODUCTION

This analysis aimed to evaluate patient-related outcomes for health-related quality of life (HRQoL) and cognitive performance in patients (≥ 16 years) with focal-onset seizures (FOS), with/without focal to bilateral tonic-clonic seizures, after initiating adjunctive brivaracetam (BRV) in routine clinical practice.

METHODS

A 12-month, prospective, real-world, noninterventional study in nine European countries (EP0077/NCT02687711) was performed. BRV was prescribed per clinical practice and the European Summary of Product Characteristics. The outcomes evaluated were the Patient Weighted Quality of Life in Epilepsy Inventory-Form 31 (QOLIE-31-P), the Clinical and the Patient's Global Impression of Change (CGIC and PGIC, respectively), and EpiTrack®. EpiTrack® scores were categorized into cognitive performance categories (excellent: ≥ 39 points; average: 32-38 points; mildly impaired: 29-31 points; significantly impaired: ≤ 28 points). The change in EpiTrack® score was evaluated [improvement: increase in score of ≥ 4 points; no change: change in score  of - 2 to 3 points (inclusive); worsening: change in score of at least - 3 points].

RESULTS

Full Analysis Set: 541 patients. 46.6% of patients reported a clinically meaningful improvement in QOLIE-31-P total score from baseline to 12 months; the mean change in total score was + 6.2 points (N = 103). Per CGIC (N = 142) and PGIC (N = 148), respectively, 69.0% and 62.8% of patients had improved in overall condition at 12 months versus baseline, while 3.5% and 8.1% had worsened. EpiTrack® categories at 12 months versus baseline showed improved cognitive performance [baseline (N = 142): significantly impaired 49.3%, mildly impaired 14.8%, average 33.1%, excellent 2.8%; 12 months (N = 61): significantly impaired 36.1%, mildly impaired 4.9%, average 52.5%, excellent 6.6%]. At 12 months, 67.2% of patients showed no significant change from baseline in EpiTrack® score, 23.0% had improved, and 9.8% had worsened (N = 61).

CONCLUSION

In patients with predominantly difficult-to-treat FOS, BRV add-on was associated with good HRQoL and cognitive functioning. Cognitive functioning remained stable for 12 months after BRV initiation in most patients; nearly one-quarter experienced significant improvements. At 12 months, 46.6% of patients reported clinically meaningful HRQoL improvements, and most showed an improved overall condition.

Second-Line Medications for Women Aged 10 to 50 Years With Idiopathic Generalized Epilepsy

Importance

Women with idiopathic generalized epilepsy (IGE) face challenges in treatment due to limited options that are both effective and safe.

Objective

To evaluate the effectiveness and safety of substitution monotherapy vs add-on therapy as second-line options for women who might become pregnant with IGE after failure of first-line antiseizure medications (ASMs) other than valproic acid.

Design, Setting, and Participants

Multicenter retrospective comparative effectiveness cohort study at 18 primary, secondary, and tertiary adult and children epilepsy centers across 4 countries, analyzing data from 1995 to 2023. Participants were women aged 10 to 50 years diagnosed with IGE who were prescribed a second line of ASM.

Main Outcomes and Measures

Treatment failure (TF), defined as the replacement or addition of a second ASM due to ineffectiveness, was compared between patients receiving ASM add-on or substitution monotherapy using inverse probability of treatment weighting (IPTW)-adjusted Cox proportional hazards regression. Exploratory analyses were also conducted to assess the effectiveness of individual ASMs and various ASM combinations.

Results

This study included 249 women with a median (IQR) age of 18.0 (15.5-22.0) years. Among them, 146 (58.6%) received an add-on regimen, and 103 (41.4%) received substitution monotherapy. During follow-up, TF occurred in 48 patients (32.9%) receiving add-on therapy and 36 (35.0%) using substitution monotherapy, with no significant differences between groups (IPTW-adjusted hazard ratio [HR], 0.89; 95% CI, 0.53-1.51; P = .69). ASM discontinuation due to ineffectiveness or adverse effects occurred in 36 patients (24.7%) receiving add-on therapy and 29 (28.2%) receiving substitution monotherapy, showing no significant differences (IPTW-adjusted HR, 0.97; 95% CI, 0.57-1.65; P = .92). Rates of ASM discontinuation due to adverse effects only were low in both groups, occurring in 13 patients (9.0%) receiving add-on therapy and 9 (8.7%) receiving a substitution monotherapy. Among add-on regimens other than valproic acid, the combination of levetiracetam and lamotrigine demonstrated a lower risk of TF compared with other combinations with levetiracetam plus other ASM (adjusted HR, 2.41; 95% CI, 1.12-5.17; P = .02) and lamotrigine plus other ASM (adjusted HR, 4.03; 95% CI, 1.73-9.39; P = .001). However, valproic acid remained the most effective second-line ASM when considering individual agents.

Conclusions and relevance

In this comparative effectiveness study of second-line treatment strategies for women with IGE, no significant differences were observed between substitution monotherapy and add-on therapy.

Unveiling distinct representations of P3a in schizophrenia through two-stimulus and three-stimulus auditory oddball paradigms

BACKGROUND

P3a event-related potential (ERP) is considered a potential biomarker for schizophrenia (SZ), can be elicited through both passive two-stimulus and active three-stimulus auditory oddball paradigms. While both types of P3a reflect involuntary attention shifts, the nuanced understanding of what P3a represents in different contexts is important and rarely studied. This study aims to examine correlations between P3a ERPs elicited from different paradigms and associations of each P3a with cognitive function, clinical symptoms, and antipsychotic medication.

METHODS

Our sample included 178 SZ patients and 127 healthy controls (HC). Data on two-stimulus paradigm, three-stimulus oddball paradigm, Chinese version of MATRICS Consensus Cognitive Battery (MCCB), symptom severity, and medication use were collected.

RESULTS

In both paradigms, SZ group's P3a amplitude was significantly reduced compared to HC's (both p < 0.05). P3a evoked by the two-stimulus paradigm and the three-stimulus paradigm were not correlated (r = -0.06, p = 0.661). Three-stimulus paradigm-P3a was significantly correlated with attention/vigilance (r = 0.27, p = 0.017) in SZ, and with working memory (r = 0.39, p = 0.001) and overall MCCB score (r = 0.25, p = 0.042) in HC. Additionally, the two-stimulus paradigm-P3a correlated with olanzapine equivalent antipsychotic dose (r = -0.26, p = 0.022).

CONCLUSIONS

Our findings offer new insights into the role of P3a in clinical research. P3a ERPs from different paradigms may represent functionally distinct components. The context in which the P3a is elicited should be taken into account when discussing its functional or neurocognitive significance.

Cognitive phenotypes in patients with drug-resistant temporal lobe epilepsy: Relationships with cortisol and affectivity

OBJECTIVE

Drug-resistant temporal lobe epilepsy (TLE) is a neurological disorder characterized by cognitive deficits. This study examined whether patients with TLE and different cognitive phenotypes differ in cortisol levels and affectivity while controlling for demographic and clinical variables. Methods: In this cross-sectional study, 79 adults with TLE underwent neuropsychological evaluation in which memory, language, attention/processing speed, executive function, and affectivity were assessed. Six saliva samples were collected in the afternoon to examine the ability of the hypothalamic-pituitary-adrenal (HPA) axis to descend according to the circadian rhythm (C1 to C6). The cortisol area under the curve concerning ground (AUCg) was computed to examine global cortisol secretion.

RESULTS

Three cognitive phenotypes were identified: memory impairment, generalized impairment, and no impairment. The memory-impairment phenotype showed higher cortisol levels at C4, C5, and C6 than the other groups (p = 0.03, η2 = 0.06), higher cortisol AUCg than the generalized-impairment phenotype (p = 0.004, η2 = 0.14), and a significant reduction in positive affectivity after the evaluation (p = 0.026, η2 = 0.11). Higher cortisol AUCg and reductions in positive affectivity were significant predictors of the memory-impairment phenotype (p < 0.001; Cox and Snell R2 = 0.47).

CONCLUSIONS

Patients with memory impairment had a slower decline in cortisol levels in the afternoon, which could be interpreted as an inability of the HPA axis to inhibit itself. Thus, chronic stress may influence hippocampus-dependent cognitive function more than other cognitive functions in patients with TLE.

Neuropsychological morbidity in the First Seizure Clinic: Prominent mood symptoms and memory issues in epilepsy

OBJECTIVE

To examine the neuropsychological morbidity across the spectrum of patients presenting to a First Seizure Clinic, and test the hypothesis that cognitive and psychological compromise is especially prominent in those diagnosed with epilepsy.

METHODS

A sample of 201 patients referred to the Austin Hospital First Seizure Clinic (FSC) underwent cognitive screening via telephone and psychological screening via online questionnaire, all prior to their diagnostic evaluation (and any attendant treatment recommendation) at the FSC. Rates of cognitive (i.e., scores <10th percentile) and psychological impairment (using established clinical cut scores) were compared against 35 demographically matched controls. Cognitive differences were explored between the most frequently encountered patient subgroups (epilepsy, n = 48; first unprovoked seizure, n = 24; acute symptomatic seizure, n = 24; syncope, n = 35) via a multivariate analysis of variance, with diagnostic labels applied retrospectively after a period of follow-up.

RESULTS

People with epilepsy were most likely to show cognitive impairments, particularly in learning and memory, with performances worse than all other FSC groups (F [3127] = 2.44, p = 0.03). Clinically significant depressive symptoms were similarly prevalent in all patient groups, with one in three at risk for Major Depressive Disorder. Elevated anxiety symptoms were common across patient groups; however, not significantly different to controls.

SIGNIFICANCE

Cognitive impairment in epilepsy and mood problems in all FSC groups are detectable via remote screening as early as the first seizure. Learning and memory difficulties are particularly prevalent in new-onset epilepsy and may lend diagnostic information when paired with clinical factors.

PLAIN LANGUAGE SUMMARY

This study explored cognitive and psychological differences between various patient groups attending an Australian First Seizure Clinic. We found that learning and memory abilities were poorer in people with epilepsy than other patient groups including those with non-epileptic seizures, and seizure-mimics (fainting episodes). Therefore, along with standard epilepsy investigations, memory performances could help to predict which patients have epilepsy versus a non-epileptic condition after a first suspected seizure. Further, approximately one in three from each patient group showed high symptoms of depression and anxiety. The findings highlight the importance of evaluating cognition and mood in people with first seizures.

Changes in Response Inhibition, Visual Anticipation and Verbal Fluency During Vagus Nerve Stimulation Therapy in Patients With Drug-Resistant Epilepsy

BACKGROUND

The effect of vagus nerve stimulation (VNS) on cognitive domain of attention and executive functions (AEFs) has not been extensively researched. This study was set up to investigate performance variability on cognitive tests assessing AEFs in drug-resistant epilepsy (DRE) patients receiving VNS therapy during a follow-up of up to 5 years.

METHODS

Thirty-three DRE patients were assessed with the interference, maze, and written verbal fluency tests as a part of EpiTrack screening before and after VNS implantation through repeated follow-ups according to the clinical VNS protocol. A linear mixed-effects model was used to analyse changes in test scores.

RESULTS

Maze performance improved significantly by an average of 0.20 s per month (95% confidence interval (CI): -0.365 to -0.041; p = 0.014). Interference performance improved by an average of 0.05 s per month (p = 0.207) and number of words increased by an average of 0.03 words per month (p = 0.079) on the verbal fluency test. On the maze test, patients with psychiatric comorbidities improved the most (0.52 s/month, p = 0.001), while on the interference test, patients with frontal lobe epilepsy (FLE), those taking 1-2 antiseizure medications (ASMs) and patients with focal to bilateral tonic-clonic seizures improved the most (0.14 s/month, p = 0.005; 0.14 s/month, p = 0.033 and 0.16 s/month, p = 0.087, respectively). For verbal fluency, no clinically meaningful improvement was noted in any of the groups.

CONCLUSION

During the follow-up, maze performance markedly improved, while performance on the interference and verbal fluency tasks remained relatively stable at the group level. Accordingly, visual anticipation and planning improved during VNS therapy whereas response inhibition was unchanged at the group level despite significant enhancements in patients with FLE and those taking 1-2 ASM. Furthermore, the presence of psychiatric comorbidities correlated with even greater improvement on maze performance.

Epilepsy and Neuropsychology

Neuropsychological evaluation is an essential component of clinical care for people with epilepsy and also has a specialized role in predicting cognitive outcome after epilepsy surgery. Neuropsychological research in the field of epilepsy has had a significant impact on our knowledge regarding memory and language systems, lateralization of cognitive functions, and the heterogeneity in cognitive phenotypes among people with epilepsy. Interventions that consider the impact of health disparities, cognition, psychological functioning, individual risk and resilience factors, and modifiable lifestyle factors, are critical for optimizing cognitive functioning, psychological health, and quality of life for people with epilepsy.

Beyond brain injury: Examining the neuropsychological and psychosocial sequelae of post-traumatic epilepsy

OBJECTIVE

This study investigates neuropsychological and psychosocial outcomes in patients with traumatic brain injury (TBI) and post-traumatic epilepsy (PTE) compared to a healthy control group.

METHOD

Utilizing a quasi-experimental cross-sectional design, the research involved patients with TBI and PTE referred from a Taiwanese medical center. An age- and education-matched control group of healthy adults without traumatic injuries was also recruited. The study involved analyzing retrospective medical records and applying a comprehensive suite of neuropsychological tests and psychosocial questionnaires.

RESULTS

Executive function measures revealed significantly reduced performance in both the TBI and PTE groups compared to controls. Specifically, the MoCA scores were lowest in the PTE group, followed by the TBI group, and highest in the controls. Measures of subjective symptomatology showed comparably elevated levels in both the TBI and PTE groups relative to controls.

CONCLUSION

The research suggests that PTE may intensify the difficulties faced by individuals with TBI, but its impact on overall recovery might not be significant, considering the trajectory of the brain injury itself. Notably, the MoCA results indicate that cognitive deficits are more pronounced in PTE patients compared to those with TBI, underscoring the necessity for targeted neuropsychological assessments. Further investigation is essential to explore PTE's broader neuropsychological and psychosocial impacts. These findings advocate for tailored care strategies that address both neuropsychological and psychosocial needs, ensuring comprehensive management of TBI and PTE.

Does epilepsy differentially affect different types of memory?

Despite the recognition that epilepsy can substantially disrupt memory, there are few published accounts of whether and how this disruption varies across different types of memory and/or different types of epilepsy. This review explores four main questions: (1) Are working, episodic and semantic memory differentially affected by epilepsy? (2) Do various types of epilepsy, and their treatment, have different, specifiable effects on memory? (3) Are the usual forms of neuropsychological assessments of memory - many or most designed for other conditions - appropriate for patients with epilepsy? (4) How can research on epilepsy contribute to our understanding of the neuroscience of memory? We conclude that widespread and multifactorial problems are seen in working memory in all patient groups, while patients with temporal lobe epilepsy seem particularly prone to episodic memory deficit, and those with frontal lobe epilepsy to executive function deficits that may in turn impair semantic control. Currently, it is difficult to make individual patient predictions about likely memory deficits based on seizure aetiology and type, but it is possible to guide and tailor neuropsychological assessments in an individualised way. We make recommendations for future directions in validating and optimising neuropsychological assessments, and consider how to approach effective shared decision making about the pros and cons of seizure treatment strategies, especially at crucial educational stages such as adolescence.

Severe memory decline along with unaffected executive functions under 400 mg/day of cenobamate leading to a collapse in school performance

Cenobamate (CNB) is one of the newer antiseizure medications for the treatment of focal-onset seizures. The cognitive profile of CNB is not yet known in detail. Here we present the case of an 18-year-old male high school student with epilepsy who received adjunctive CNB. Under 400 mg/d of CNB in combination with lamotrigine, a neuropsychological reassessment revealed a severe deterioration of the formerly normal episodic memory functions, while executive functions remained unaffected. The de novo memory deficit had already led to a collapse in school performance and he unexpectedly failed to obtain the general qualification for university entrance. Given the beneficial effect of CNB on seizure control, a dose reduction of CNB to 200 mg/d and introduction of valproic acid was performed. This led to a full recovery of objective memory performance. To our knowledge this is the very first report of a dose-dependent, selective and severe decline in episodic memory performance under CNB, potentially impeding academic achievement. The findings call for a cognitive monitoring of CNB which also addresses episodic memory in addition to executive functions. Systematic studies on episodic memory upon CNB treatment would help to appreciate the scope of this apparently reversible adverse effect.

[Memory impairments in temporal lobe epilepsy]

Temporal lobe epilepsy is known to present with various cognitive impairments, among which memory deficits are frequently reported by patients. Memory deficits can be classified into two types: classical hippocampal amnesia, which is characterized by abnormalities detected in neuropsychological assessments, and atypical memory deficits, such as accelerated long-term amnesia and autobiographical memory impairment, which cannot be identified using standard testing methods. These deficits are believed to arise from a complex interplay among structural brain abnormalities, interictal epileptic discharges, pharmacological factors, and psychological states. While fundamental treatments are limited, there are opportunities for interventions such as environmental adjustments and rehabilitation. This review article aims to provide a comprehensive overview of the types, underlying pathophysiology, and intervention methods for memory disorders observed in patients with temporal lobe epilepsy.

Clinical utility of Epitrack for differentiating profiles and patterns of post-surgical change in memory and quality of life in patients with drug-resistant epilepsy

PURPOSE

To assess whether performance in attention and executive functions evaluated with the Epitrack screening tool before surgery can differentiate memory and quality of life (QOL) profiles, and detect different post-surgical change patterns in these variables in patients with epilepsy.

METHODS

This is a longitudinal study. Seventy-seven patients with drug-resistant epilepsy (mean age = 37.91) underwent a neuropsychological assessment before and one year after surgery. Epitrack, a screening tool that exclusively evaluates attention and executive functioning, was administered in the pre-surgical assessment, and verbal and visual memory and QOL were assessed before and after surgery.

RESULTS

Patients with impaired Epitrack performance had poorer verbal and visual memory than those with intact Epitrack performance, regardless of the time point (for all, p < 0.0001). They also showed a post-surgical decline in immediate verbal recall (p = 0.04) and discriminability (p = 0.001). Patients with intact Epitrack performance did not exhibit this decline. Epitrack total score significantly contributed to 13 and 11% of the variance of post-surgical changes in immediate verbal recall and discriminability, respectively. Epitrack groups did not differ in QOL profiles or changes, but post-surgical immediate verbal recall improvements were related to post-surgical QOL improvements.

CONCLUSION

Our findings underline the utility of Epitrack screening tool to detect different patterns of verbal and visual memory dysfunction, as well as to predict post-surgical verbal memory decline in patients with drug-resistant epilepsy. Patients with lower pre-surgical Epitrack scores appear to be at increased risk for post-surgical memory decline.

Changes in overlap of subjective and objective cognition over time in epilepsy surgery candidates

PURPOSE

Subjective and objective cognition often show weak overlap in persons with epilepsy (PWE). Over- as well as underestimation may occur. In particular after epilepsy surgery, objective memory decline is often not subjectively reported. Additionally, studies on how concordance of subjective and objective cognition changes over time are missing. Therefore, we study the extent of concordance in operated and non-operated PWE over time.

METHODS

Candidates for resective epilepsy surgery were assessed between 03/18 and 12/20 (T1) with self-report questionnaires and underwent a neuropsychological examination. For 21 operated as well as 27 non-operated PWE follow-up data was obtained one to three years later (T2). Concordance of attention and memory were compared between groups and time points. Moreover, reliable change was calculated and compared between groups.

RESULTS

Of the total sample, 42 % rated their attention performance realistically and 25 % showed memory concordance. Differences in patterns of over- and underestimation between groups and over time occurred for attention, but not for memory. Overestimation of memory was more frequent in operated than non-operated PWE, especially at T2 (67% vs. 11 %). In the operated group, we mainly observed reliable improvement in subjective cognition and decline in objective memory, whereas non-operated PWE showed more frequently decline of simple attention. Reliable subjective and objective change did not co-occur.

CONCLUSION

Concordance of subjective and objective cognition is low. Over- as well as underestimation may persist over time. Domain-specific perspectives are necessary. Tendencies of operated PWE to develop overestimation of memory after surgery should be considered in neuropsychological interventions.

The role of the adenosine system in epilepsy and its comorbidities

Epilepsy is one of the most serious and common chronic neurological conditions, characterised by recurrent hypersynchronous electrical activity in the brain that lead to seizures. Despite over 50 million people being affected worldwide, only ~70% of people with epilepsy have their seizures successfully controlled with current pharmacotherapy, and many experience significant psychiatric and physical comorbidities. Adenosine, a ubiquitous purine metabolite, is a potent endogenous anti-epileptic substance that can abolish seizure activity via the adenosine A1 G protein-coupled receptor. Activation of A1 receptors decreases seizure activity in animal models, including models of drug-resistant epilepsy. Recent advances have increased our understanding of epilepsy comorbidities, highlighting the potential for adenosine receptors to modulate epilepsy-associated comorbidities, including cardiovascular dysfunction, sleep and cognition. This review provides an accessible resource of the current advances in understanding the adenosine system as a therapeutic target for epilepsy and epilepsy-associated comorbidities. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.

EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.

Impact of Polytherapy on Memory Functioning in Patients With Drug-Resistant Epilepsy: The Role of Attention and Executive Functions

OBJECTIVE

The aim was to examine the effect of polytherapy (i.e., the number of administered anti-seizure medications (ASMs)) on memory, and whether the interaction between the number of ASMs and attentional/executive functioning affect presurgical memory functioning and postsurgical memory changes in patients with drug-resistant epilepsy.

METHODS

Two studies were carried out. Study 1 consisted of a presurgical assessment of 125 adult patients, in which attention/executive function (EpiTrack screening tool) and memory were assessed (cross-sectional study). Of them, 72 patients underwent a second postsurgical evaluation, in which memory was assessed (Study 2). Patients were distributed into groups based on EpiTrack performance and number of ASMs.

RESULTS

The interaction between the number of ASMs and the attentional/executive functioning significantly affected presurgical memory, with patients with impaired EpiTrack performance taking three-four ASMs having poorer scores than patients with intact EpiTrack performance taking three-four ASMs (for all, p < .0001). This interaction also affected postsurgical memory changes, with patients with impaired Epitrack performance taking three-four ASMs having higher postsurgical decline than those with intact Epitrack performance taking three-four ASMs (for all, p < .005). No differences were found in patients taking two ASMs. Furthermore, the number of ASMs was associated with presurgical memory performance and postsurgical memory changes only in patients with impaired EpiTrack performance (for all, p < .05).

CONCLUSIONS

Our findings underline the utility of EpiTrack, together with the clinical information on the number of prescribed ASMs, to corroborate the impact of polytherapy on memory and to optimize the prediction of postsurgical memory changes.

Enhancing Executive Functions in Pediatric Epilepsy: Feasibility and Efficacy of a Computerized Cognitive Training Program

Epilepsy, a prevalent neurological disorder characterized by recurrent seizures, significantly impacts individuals' neurobiological, cognitive, and social lives. This report presents a feasibility study investigating the effects of a computerized cognitive training program on enhancing executive functions, particularly inhibitory control, in children and adolescents with epilepsy. Employing a pre-test-intervention-post-test design, the study involved 26 participants with diverse epileptic syndromes, focusing on those without severe intellectual disabilities. The intervention, based on the CogniFit Inc. platform, consisted of personalized tasks aiming to improve participants' inhibitory skills over 16 weeks, with an average of 40 sessions completed per participant. Results indicated significant improvements in reaction times and error rates in an anti-saccade task, demonstrating enhanced inhibitory control and general performance post-intervention. These findings suggest that targeted cognitive training is a feasible approach to bolster executive functions in young individuals with epilepsy, potentially improving their academic performance, employability, and social interactions. The study underscores the importance of early cognitive interventions in epilepsy management, highlighting the potential for computerized programs to aid in mitigating cognitive deficits associated with the condition.

A Ketogenic Diet may Improve Cognitive Function in Rats with Temporal Lobe Epilepsy by Regulating Endoplasmic Reticulum Stress and Synaptic Plasticity

A ketogenic diet (KD) is often used in the treatment of refractory epilepsy. Many studies have found that it also has a positive impact on cognitive comorbidities, but the specific mechanism remains unclear. In many disease models, endoplasmic reticulum stress (ERS) and synaptic plasticity is considered a new therapeutic target for improving cognitive impairment, and it has become a research focus in recent years. Recently, studies have found that a KD has a certain regulatory effect on both ERS and synaptic plasticity, but this result has not been confirmed in epilepsy. To investigate the effect of a KD on ERS and synaptic plasticity. In this study, a rat model of temporal lobe epilepsy (TLE) induced by lithium chloride-pilocarpine was used. After the model was successfully established, the rats in each group were fed a normal diet or a KD for 28 days, and the effect of a KD on the latency and seizure frequency of spontaneous recurrent seizures (SRSs) was observed via video monitoring. Subsequently, a Morris water maze was used to evaluate the spatial learning and memory abilities of the rats in each group; the ultrastructure of the ER and the synapses of the hippocampus were observed by transmission electron microscopy, and the dendritic spine density of the hippocampus was analysed by Golgi staining. Long-term potentiation (LTP) was used to detect the synaptic plasticity of the rats' hippocampi, and the expression of ERS-related proteins and synapse-related proteins was detected by Western blotting. A KD effectively reduced the frequency of SRSs in rats with TLE and improved their learning and memory impairment. Further investigations found that a KD inhibited the up-regulation of glucose-regulated protein 78, phospho-protein kinase-like ER kinase, phosphorylated α subunit of eukaryotic initiation factor 2, activating transcription factor 4 and C/EBP homologous protein expression in the hippocampi of rats with TLE and protected the ultrastructure of the neuronal ER, suggesting that a KD suppressed excessive ERS induced by epilepsy. Concurrently, we also found that a KD not only improved the synaptic ultrastructure and increased the density of dendritic spines in rats with TLE but also reversed the epilepsy-induced LTP deficit to some extent. More importantly, the expression of postsynaptic density protein 95, synaptotagmin-1 and synaptosomal-associated protein 25 in the hippocampi of rats with epilepsy was significantly increased after KD intervention. The study findings indicate that a KD improves learning and memory impairment in rats with epilepsy, possibly by regulating ERS and synaptic plasticity.

EEG changes induced by meditative practices: State and trait effects in healthy subjects and in patients with epilepsy

The effect of meditation on brain activity has been the topic of many studies in healthy subjects and in patients suffering from chronic diseases. These effects are either explored during meditation practice (state effects) or as a longer-term result of meditation training during the resting-state (trait). The topic of this article is to first review these findings by focusing on electroencephalography (EEG) changes in healthy subjects with or without experience in meditation. Modifications in EEG baseline rhythms, functional connectivity and advanced nonlinear parameters are discussed in regard to feasibility in clinical applications. Secondly, we provide a state-of-the-art of studies that proposed meditative practices as a complementary therapy in patients with epilepsy, in whom anxiety and depressive symptoms are prevalent. In these studies, the effects of standardized meditation programs including elements of traditional meditation practices such as mindfulness, loving-kindness and compassion are explored both at the level of psychological functioning and on the occurrence of seizures. Lastly, preliminary results are given regarding our ongoing study, the aim of which is to quantify the effects of a mindfulness self-compassion (MSC) practice on interictal and ictal epileptic activity. Feasibility, difficulties, and prospects of this study are discussed.

Cognitive and psychological dysfunction is present after a first seizure, prior to epilepsy diagnosis and treatment at a First Seizure Clinic

OBJECTIVE

Neuropsychological comorbidities found in chronic epilepsy have also been reported earlier in the disease course. However, recurrent seizures, antiseizure medication (ASM), and adjustment to a chronic diagnosis remain potential confounds of this literature. It thus remains unclear whether these comorbidities are primary or secondary attributes of epilepsy. To capture individuals as close to disease onset as possible, we studied the cognitive and psychological functioning in adults after their first seizure, yet prior to epilepsy diagnosis and treatment.

METHODS

Using a telehealth-based prospective design, we screened cognition, mood, and anxiety symptoms in adult patients referred to a First Seizure Clinic (FSC), who were over 18 years, English-speaking and not taking ASM. We screened cognition via telephone, and psychological symptoms via online questionnaires, all prior to the patients' diagnostic evaluation. Data were collected on 32 individuals subsequently diagnosed with epilepsy at the FSC, and 30 healthy controls from the community, who were matched to the epilepsy group for age, gender, and education.

RESULTS

A multivariate analysis of variance revealed that the groups differed significantly on combined cognitive measures with a large effect size (F[1,56] = 5.75, p < 0.001, η2 = 0.45). Post-hoc analyses showed that performances on measures of verbal memory, working memory, and executive functions were significantly worse for the newly diagnosed epilepsy group than controls. The epilepsy group also exhibited higher rates of clinically significant depressive and anxiety symptoms.

SIGNIFICANCE

Cognitive and psychological dysfunction is prevalent in people with epilepsy as early as the first seizure event, before the influence of diagnosis, ASM and recurrent seizures. Their neuropsychological profile parallels that seen in chronic epilepsy, showing that this dysfunction is already present at the very onset of the disease. The current study demonstrates the viability of telehealth neuropsychological screening for all new epilepsy cases.

PLAIN LANGUAGE STATEMENT

The results of this study show, using telephone-based cognitive assessment and online questionnaires, that people with newly diagnosed epilepsy can experience problems with their thinking and memory skills, and low mood and anxiety, as early as after their first seizure. These issues are apparent at the very beginning of the disease, before an epilepsy diagnosis is made and before antiseizure medication is commenced, which suggests that they are due to the underlying brain disturbance, rather than the secondary effects of seizures, treatment, or lifestyle changes. Telehealth-screening of thinking skills and mental health for all new epilepsy cases is recommended to promote early management of such problems.

Greater need for treatment optimization in patients with epilepsy initiating adjunctive therapy: Results of a retrospective claims analysis of antiseizure medication drug load in the United States

BACKGROUND

This retrospective, observational study used US claims data to assess changes in antiseizure medication (ASM) drug load for a cohort of patients with epilepsy.

METHODS

Adults (≥18 years) with a diagnosis of epilepsy (ICD-10 code G40.xxx) who started new adjunctive ASM treatment with one of 4 branded (brivaracetam, eslicarbazepine, lacosamide, perampanel) or 4 unbranded (carbamazepine, lamotrigine, levetiracetam, topiramate) ASMs between January 1, 2016 and December 31, 2020 were identified from IBM MarketScan® research databases (primary study population). Patients must have been continuously enrolled 360 days before the start of the new ASM (eligibility period). Follow-up was from the start of new ASM until Day 540 (∼18 months). The primary endpoint was concomitant ASM drug load, which included all ASMs except the new (comparator) ASM. A sensitivity analysis population included adults with epilepsy who were continuously enrolled for ≥ 180 days during at least one calendar year in the study period (2016-2020), whether or not the comparator ASM was new or existing during that period. Total ASM drug load, which included comparator ASM and concomitant ASMs, was assessed in the sensitivity analysis population.

RESULTS

In total, 21,332 patients were included in the primary study population, of which 5767 initiated branded ASMs and 15,565 initiated unbranded ASMs. A total of 392,426 patients were included in the sensitivity analysis population during at least one calendar year 2016-2020. Concomitant ASM drug load increased in the 360 days prior to new ASM start and slightly declined thereafter. Mean concomitant ASM drug load for the primary population was 1.6 (SD 1.8) at new ASM start. Concomitant drug load was higher among those starting branded ASM comparators compared to those starting unbranded comparators. Mean total ASM drug load for patients increased over time and was approximately double for patients exposed to branded ASMs (mean range 2.1 to 2.7) compared to that of patients exposed to any unbranded ASM (mean range 1.0 to 1.3).

CONCLUSION

Concomitant ASM drug load increased prior to addition of new ASM, with higher increases observed among patients starting branded vs unbranded ASMs, followed by slight decreases thereafter. Total drug load increased linearly among all patients. These findings underscore the need for ongoing ASM regimen evaluation and treatment optimization in patients with epilepsy.

Complex executive functions assessed by the trail making test (TMT) part B improve more than those assessed by the TMT part A or digit span backward task during vagus nerve stimulation in patients with drug-resistant epilepsy

Introduction

There is a paucity of clinical studies examining the long-term effects of vagus nerve stimulation (VNS) on cognition, although a recent study of patients with drug-resistant epilepsy (DRE) treated with VNS therapy demonstrated significant improvement in executive functions as measured by the EpiTrack composite score. The present study aimed to investigate performance variability in three cognitive tests assessing executive functions and working memory in a cohort of DRE patients receiving VNS therapy during a follow-up duration of up to 5 years.

Methods

The study included 46 DRE patients who were assessed with the Trail Making Test (TMT) (Parts A and B) and Digit Span Backward (DB) task prior to VNS implantation, 6 months and 12 months after implantation, and yearly thereafter as a part of the clinical VNS protocol. A linear mixed-effects (LME) model was used to analyze changes in test z scores over time, accounting for variations in follow-up duration when predicting changes over 5 years. Additionally, we conducted descriptive analyses to illustrate individual changes.

Results

On average, TMT-A z scores improved by 0.024 units (95% confidence interval (CI): 0.006 to 0.042, p = 0.009), TMT-B z scores by 0.034 units (95% CI: 0.012 to 0.057, p = 0.003), and DB z scores by 0.019 units per month (95% CI: 0.011 to 0.028, p < 0.001). Patients with psychiatric comorbidities achieved the greatest improvements in TMT-B and DB z scores among all groups (0.0058 units/month, p = 0.036 and 0.028 units/month, p = 0.003, respectively). TMT-A z scores improved the most in patients taking 1-2 ASMs as well as in patients with psychiatric comorbidities (0.042 units/month, p = 0.002 and p = 0.003, respectively).

Conclusion

Performance in all three tests improved at the group level during the follow-up period, with the most robust improvement observed in TMT-B, which requires inhibition control and set-switching in addition to the visuoperceptual processing speed that is crucial in TMT-A and working-memory performance that is essential in DB. Moreover, the improvement in TMT-B was further enhanced if the patient had psychiatric comorbidities.

Reductions in concomitant antiseizure medication drug load during adjunctive cenobamate therapy: Post-hoc analysis of a subset of patients from a phase 3, multicenter, open-label study

OBJECTIVE

Many patients with epilepsy require polytherapy, which increases their antiseizure medication (ASM) drug load, a measure that considers the doses of all ASMs a patient is taking. Changes in concomitant ASM drug load after adding cenobamate were evaluated post-hoc in a subset of the open-label, phase 3 study.

METHODS

Patients 18-70 years old with uncontrolled focal seizures taking 1-3 ASMs were enrolled. Total concomitant ASM drug load (not including cenobamate) was calculated by dividing the patient's prescribed dose for each ASM by its defined daily dose, per the World Health Organization, then summing the ratios. Changes in concomitant ASM drug load were measured from baseline in 3-month intervals up to 24 months by both total and class-specific ASM drug load. Subgroups of interest included: older adults (65-70 years), prior epilepsy-related surgery vs none, and baseline seizure frequency < 3 vs ≥ 3 seizures/28 days.

RESULTS

Data from 240 patients were available (mean age 41.8 years, mean baseline drug load 3.57). Following cenobamate initiation, the mean concomitant ASM drug load was reduced by 29.4 % at Month 12 % and 31.8 % at Month 24. Reductions occurred in all assessed ASM drug classes, with the largest reduction in benzodiazepines (55.2 % at Month 24). Each assessed subgroup exceeded a 30 % reduction in concomitant ASM drug load at Month 24. Over 24 months, maintenance of ≥ 50 % response occurred in 89.3 %, 86.4 %, and 90.6 % of patients with low (-0.25 to <0), moderate (-0.59 to -0.25), or high (-3.3 to -0.59) numerical reductions in concomitant ASM drug load from baseline, respectively, compared with 86.0 % in patients with no change in drug load; maintenance of 100 % response occurred in 80.7 %, 84.3 %, and 70.0 % of patients with low, moderate, or high numerical reductions in concomitant ASM drug load, compared with 82.0 % in patients with no change.

CONCLUSIONS

Adding cenobamate led to reduced mean concomitant ASM drug loads during 1 and 2 years of treatment. Reductions occurred regardless of ASM drug class, patient age, or epilepsy disease characteristics and did not impact maintenance of response rates.

Expert opinion on diagnosis and management of epilepsy-associated comorbidities

Apart from seizure freedom, the presence of comorbidities related to neurological, cardiovascular, or psychiatric disorders is the largest determinant of a reduced health-related quality of life in people with epilepsy (PwE). However, comorbidities are often underrecognized and undertreated, and clinical management of comorbid conditions can be challenging. The focus of a comprehensive treatment regimen should maximize seizure control while optimizing clinical management of treatable comorbidities to improve a person's quality of life and overall health. A panel of four European epileptologists with expertise in their respective fields of epilepsy-related comorbidities combined the latest available scientific evidence with clinical expertise and collaborated to provide consensus practical advice to improve the identification and management of comorbidities in PwE. This review provides a critical evaluation for the diagnosis and management of sleep-wake disorders, cardiovascular diseases, cognitive dysfunction, and depression in PwE. Whenever possible, clinical data have been provided. The PubMed database was the main search source for the literature review. The deleterious pathophysiological processes underlying neurological, cardiovascular, or psychiatric comorbidities in PwE interact with the processes responsible for generating seizures to increase cerebral and physiological dysfunction. This can increase the likelihood of developing drug-resistant epilepsy; therefore, early identification of comorbidities and intervention is imperative. The practical evidence-based advice presented in this article may help clinical neurologists and other specialist physicians responsible for the care and management of PwE.

Cognitive and psychiatric adverse events during adjunctive cenobamate treatment in phase 2 and phase 3 clinical studies

OBJECTIVE

Cognitive and psychiatric adverse events in patients with epilepsy are important determinants of therapeutic outcomes and patient quality of life. We assessed the relationship between adjunctive cenobamate treatment and selected cognitive and psychiatric treatment-emergent adverse events (TEAEs) in adults with uncontrolled focal epilepsy.

METHODS

This was a retrospective analysis of pooled populations of patients with focal epilepsy from two phase 2, randomized, double-blind clinical trials; two open-label extensions (OLEs) of those trials; and a long-term, open-label, phase 3 safety study. Occurrence of cognitive and psychiatric TEAEs in patients treated with adjunctive cenobamate or placebo during double-blind treatment were evaluated. Exposure-adjusted incidence rates of the cognitive and psychiatric TEAEs, defined as the number of TEAEs per patient-year of treatment, during up to 7 years of long-term adjunctive cenobamate treatment, were determined in the pooled OLE and phase 3 patient populations.

RESULTS

The pooled randomized trials resulted in a population of 442 patients treated with cenobamate (100 mg/day: n = 108; 200 mg/day: n = 223; 400 mg/day: n = 111) and 216 placebo-treated patients. The combined open-label studies resulted in pooled populations of cenobamate-treated patients ranging from n = 1690 during Year 1 to n = 103 during Year 7. Among cenobamate-treated (all doses) and placebo-treated patients during double-blind treatment, cognitive TEAEs were reported by ≤ 1.9 % (range, 0 %-1.9 %) and ≤ 0.5 % (range, 0 %-0.5 %), respectively, and psychiatric TEAEs by ≤ 3.6 % (range, 0 %-3.6 %) and ≤ 3.2 % (range, 0 %-3.2 %), respectively. During up to 7 years of open-label adjunctive cenobamate treatment, exposure-adjusted incidence rates of cognitive and psychiatric TEAEs were < 0.018 and < 0.038 events per patient-year, respectively. Discontinuation of adjunctive cenobamate due to cognitive or psychiatric TEAEs assessed in this study during double-blind or open-label treatment occurred in ≤ 0.3 % and ≤ 1.7 % of patients, respectively.

CONCLUSIONS

Cognitive and psychiatric TEAEs were reported by similar numbers of cenobamate- and placebo-treated patients during double-blind adjunctive cenobamate treatment (< 4 % of patients), and exposure-adjusted incidence rates of these TEAEs remained low during open-label cenobamate treatment for up to 7 years. Treatment discontinuations due to these TEAEs were rare. The results of this post-hoc analysis indicate that adjunctive cenobamate treatment exhibits a low incidence of cognitive or psychiatric TEAEs in patients with uncontrolled focal seizures.

Prospective study of cenobamate on cognition, affectivity, and quality of life in focal epilepsy

OBJECTIVE

Cenobamate is a recently approved antiseizure medication that proved to be safe and effective in randomized controlled trials. However, little is known about its impact on some areas frequently affected by epilepsy. For this reason, we explored the effects of cenobamate on cognitive performance, as well as on negative affectivity and quality of life in a sample of patients with drug-resistant epilepsy.

METHODS

Two prospective cohort studies were carried out. In Study 1, 32 patients (22 men and 10 women) underwent a baseline (T0) and a short-term (T1) neuropsychological assessment after 3 months of cenobamate administration. In Study 2, 22 patients (16 men and 6 women) from the T1 sample also underwent a baseline and a follow-up evaluation (T2) 6 months after T0.

RESULTS

No significant differences were found in cognitive variables, negative affectivity, and quality of life either in Study 1 or Study 2. Similarly, based on the reliable change index, it was found that most patients showed no changes in these variables.

SIGNIFICANCE

These results suggest that cenobamate is a safe antiseizure medication in terms of cognition, negative affectivity, or quality of life since no adverse events have been found after 3 and 6 months of treatment.

PLAIN LANGUAGE SUMMARY

Cenobamate is a new antiseizure medication. In patients with epilepsy, cenobamate seems to not affect cognition, anxiety, depression, or quality of life.

Longitudinal EpiTrack assessment of executive functions following vagus nerve stimulation therapy in patients with drug-resistant epilepsy

OBJECTIVE

To investigate executive functions and attention with repeated EpiTrack evaluations in a group of DR patients with drug-resistant epilepsy (DRE) receiving vagus nerve stimulation (VNS) during a follow-up duration of up to 5 years.

METHODS

The study involved 33 patients with DRE who were assessed with EpiTrack as a part of the clinical VNS protocol. Evaluations were scheduled prior to VNS implantation and then at 6 months, 12 months, and yearly thereafter. However, the COVID-19 pandemic disrupted follow-up. Therefore, changes in EpiTrack total scores over time were analyzed using a linear mixed-effects (LMEs) model to compensate for the variation in follow-up duration when predicting EpiTrack total score changes over 5 years.

RESULTS

The median follow-up time was 29 months. During each month, the EpiTrack total score was predicted to increase by 0.07 units (95% confidence interval [CI]: 0.01-0.12, P = 0.02), corresponding to a change from a baseline score of 27.3 (severe impairment) to a score of 28.9 (mild impairment) at 2 years and a score of 31.5 (almost normal) at 5 years. In the group of patients with psychiatric comorbidities, the EpiTrack total score increased by 0.14 units per month (P = 0.003), which was 3.5-fold higher than the increase of patients without psychiatric comorbidities. For the patients taking 1-2 antiseizure medications (ASMs), the EpiTrack total score increased by 0.11 units per month (P = 0.005), which was almost quadruple the rate of patients taking 3-4 ASMs.

SIGNIFICANCE

Based on EpiTrack total scores, the LME model predicted a four-point improvement in executive functions among patients with DRE at 5 years after the initiation of VNS, representing a clinically meaningful change. DRE patients with comorbid depression seemed to experience the most cognitive benefits. In addition, better cognitive outcomes were achieved if the patient took less than three ASMs.

PLAIN LANGUAGE SUMMARY

Executive functions and attention may improve during vagus nerve stimulation therapy in patients with drug-resistant epilepsy. Epilepsy patients who have depression or use fewer than three antiseizure medications are likely to benefit cognitively more from the treatment.

Effect of Cenobamate on Cognition in Patients with Drug-Resistant Epilepsy with Focal Onset Seizures: An Exploratory Study

BACKGROUND AND OBJECTIVE

Most second and third generation antiseizure medications (ASMs) are associated with cognitive adverse events, which are a major concern for patients. However, the profile of cognitive adverse events differs between ASMs. This study investigated the effects of cenobamate on cognition in patients with drug-resistant epilepsy (DRE) within the Spanish Expanded Access Program (EAP).

METHODS

This was a retrospective, observational study. Inclusion criteria were age ≥ 18 years, DRE with focal seizures, and availability of cognition assessments and EAP authorization. Data were sourced from the clinical records of patients who took part in the Spanish cenobamate EAP. Primary endpoints included cognition (based on 20 neuropsychological outcomes, including verbal and visuospatial episodic memory, verbal fluency, executive function, working memory, attention, and speed of processing), seizure frequency, and concomitant antiseizure medication (ASM) usage at 6 months.

RESULTS

The study included 20 patients; 10 patients (50%) had daily seizures, 7 (35%) had weekly seizures and 3 (15%) had monthly seizures. The median number of prior antiseizure medications (ASMs) and concomitant ASMs were 10 and 3, respectively. Mean cenobamate doses were 12.5 mg/day at baseline and 191.2 mg/day at 6 months. There was a statistically significant improvement in cognitive scores between baseline and 6 months for two measures of verbal episodic memory (p = 0.0056 and p = 0.0013) and one measure of visuospatial episodic memory (p = 0.011), and a significant worsening in cognitive score for attention (p = 0.030). At 6 months, 14 patients (70%) had a ≥ 50% reduction in seizure frequency, 3 patients (15%) had a ≥ 90% reduction, and 1 patient (5%) was seizure free. There were significant decreases in the mean number of concomitant ASMs (p = 0.0009), the sum of the ratios of prescribing daily dose/daily defined dose (total ratio of DDD) for concomitant ASMs (p < 0.0001), and concomitant ASM drug load (p = 0.038) between baseline and 6 months. Total ratio of DDD was significantly lower at 6 months for perampanel (p = 0.0016), benzodiazepines (p = 0.035), and sodium channel blockers (p = 0.0005) compared with baseline. Based on analysis of covariance, cognitive tests related to verbal or visuospatial episodic memory (e.g., RT of FCSRT, or ROCFT), executive functions (e.g., TMT-B), and processing speed (some 5-Digit Test subtests) appeared to be closely related to the reduction in pharmacological burden rather than the improvement in seizure control.

CONCLUSIONS

Significant improvements in cognition, seizure frequency, and concomitant ASM usage were observed after the introduction of cenobamate in patients with DRE in a real-world setting. Covariance analysis supports the reduction in concomitant ASMs as the most important factor driving cognitive improvements with cenobamate. As this was an exploratory study with an uncontrolled, retrospective design and a low number of patients, further studies are required to confirm the findings.

Migraine - a borderland disease to epilepsy: near it but not of it

BACKGROUND

Migraine and epilepsy are two paroxysmal chronic neurological disorders affecting a high number of individuals and being responsible for a high individual and socioeconomic burden. The link between these disorders has been of interest for decades and innovations concerning diagnosing and treatment enable new insights into their relationship.

FINDINGS

Although appearing to be distinct at first glance, both diseases exhibit a noteworthy comorbidity, shared pathophysiological pathways, and significant overlaps in characteristics like clinical manifestation or prophylactic treatment. This review aims to explore the intricate relationship between these two conditions, shedding light on shared pathophysiological foundations, genetic interdependencies, common and distinct clinical features, clinically overlapping syndromes, and therapeutic similarities. There are several shared pathophysiological mechanisms, like CSD, the likely underlying cause of migraine aura, or neurotransmitters, mainly Glutamate and GABA, which represent important roles in triggering migraine attacks and seizures. The genetic interrelations between the two disorders can be observed by taking a closer look at the group of familial hemiplegic migraines, which are caused by mutations in genes like CACNA1A, ATP1A2, or SCN1A. The intricate relationship is further underlined by the high number of shared clinical features, which can be observed over the entire course of migraine attacks and epileptic seizures. While the variety of the clinical manifestation of an epileptic seizure is naturally higher than that of a migraine attack, a distinction can indeed be difficult in some cases, e.g. in occipital lobe epilepsy. Moreover, triggering factors like sleep deprivation or alcohol consumption play an important role in both diseases. In the period after the seizure or migraine attack, symptoms like speech difficulties, tiredness, and yawning occur. While the actual attack of the disease usually lasts for a limited time, research indicates that individuals suffering from migraine and/or epilepsy are highly affected in their daily life, especially regarding cognitive and social aspects, a burden that is even worsened using antiseizure medication. This medication allows us to reveal further connections, as certain antiepileptics are proven to have beneficial effects on the frequency and severity of migraine and have been used as a preventive drug for both diseases over many years.

CONCLUSION

Migraine and epilepsy show a high number of similarities in their mechanisms and clinical presentation. A deeper understanding of the intricate relationship will positively advance patient-oriented research and clinical work.

Normalization and cross-sectional validation of an extended Adverse Event Profile (E AEP) in a large cohort of patients with epilepsy

PURPOSE

The Liverpool Adverse Event Profile (L AEP) is commonly used in clinical practice and pharmacological trials for the monitoring of side effects of anti-seizure medication (ASM). However potentially unrelated, additional symptoms and normative data should be considered to put patients´ complaints into perspective.

METHODS

An extended 32-item AEP (E AEP) was given to 537 healthy subjects and 1,605 patients with epilepsy as part of the Bonn ASM side effect registry. The tool was factor-analyzed, corrected for age, gender, and repeated application, and related to drug load and individual substances (with N> 100) on item and scale level (total E AEP and its subscales cognition, dizziness, energy, mood, bodily symptoms, aggression, and sexuality).

RESULTS

Compared to non-normalized results, at item level, between one and two-thirds of responses suggesting impairment were found to be unlikely to be related to ASM treatment after normalization. Binary regression analyses revealed differential effects of medication choice, but also of antidepressants and neuroleptics on complaint domains. The explained variance was better for physical than psychological domains. The results reflect both known drug side effects and indications. Patients´ explicit attribution of problems to their medications barely improved the correlation of the E AEP and treatment parameters.

CONCLUSION

Application of a norm-referenced AEP is highly recommended to avoid overestimation of treatment related problems in patients with epilepsy. It allows evaluation on item and scale level for individuals as well as groups in drug trials. Plausible relations to individual drugs and to drug load can be demonstrated. The explanatory power was better for physical than psychological domains. Drug-related complaint patterns reflect known drug side effects (e.g. perampanel and brivaracetam with aggression) as well as drug indications (e.g. lamotrigine for depression). This is likely to be particularly relevant when side effects may have affected treatment decisions. Longitudinal evaluation with repeated application of the E AEP with changes of drug treatment is in progress.

Cognitive effect of antiseizure medications in medial temporal lobe epilepsy

BACKGROUND AND PURPOSE

The specific effects of antiseizure medications (ASMs) on cognition are a rich field of study, with many ongoing questions. The aim of this study was to evaluate these effects in a homogeneous group of patients with epilepsy to guide clinicians to choose the most appropriate medications.

METHODS

We retrospectively identified 287 refractory patients with medial temporal lobe epilepsy associated with hippocampal sclerosis. Scores measuring general cognition (global, verbal and performance IQ), working memory, episodic memory, executive functions, and language abilities were correlated with ASM type, number, dosage and generation (old vs. new). We also assessed non-modifiable factors affecting cognition, such as demographics and epilepsy-related factors.

RESULTS

Key parameters were total number of ASMs and specific medications, especially topiramate (TPM) and sodium valproate (VPA). Four cognitive profiles of the ASMs were identified: (i) drugs with an overall detrimental effect on cognition (TPM, VPA); (ii) drugs with negative effects on specific areas: verbal memory and language skills (carbamazepine), and language functions (zonisamide); (iii) drugs affecting a single function in a specific and limited area: visual denomination (oxcarbazepine, lacosamide); and (iv) drugs without documented cognitive side effects. Non-modifiable factors such as age at testing, age at seizure onset, and history of febrile seizures also influenced cognition and were notably influenced by total number of ASMs.

CONCLUSION

We conclude that ASMs significantly impact cognition. Key parameters were total number of ASMs and specific medications, especially TPM and VPA. These results should lead to a reduction in the number of drugs received and the avoidance of medications with unfavorable cognitive profiles.

Dosage, time, and polytherapy dependent effects of different levetiracetam regimens on cognitive function

OBJECTIVE

Cognitive impairment is a potential drawback of antiseizure medications. This study aimed to evaluate the impact of different levetiracetam drug regimens on cognitive function.

METHODS

A retrospective analysis identified 221 patients diagnosed with seizures who underwent cognitive screening. Patients were categorized into four groups: no medications, non-levetiracetam medications, high and low dose levetiracetam. Composite scores determined low and high levetiracetam groups whereby one point was added for each increment in dosage, duration since uptake, and concurrent anti-seizure medication. Variables known to affect cognition were recorded and classified as demographic, seizure-related, diagnosis-related, and psychopathology. Logistic regression was used to identify variables associated with cognitive scores below cut-off.

RESULTS

Multivariable analysis found being male, non-active in the community, less than 12 years of education, left temporal lobe epilepsy, high seizure frequency, and depression were associated with poor cognitive performance. In a final regression analysis, the high levetiracetam group exhibited a 4.5-fold higher likelihood of scoring below cut-off than the medication-free group (OR 4.5, CI 1.5-13.6, p<.08). Depression (OR 2.1, CI 1.1-3.9, p<.03), being male (OR 2.2, CI 1.1-4.3, p<.02), and not being active in the community (OR 3.8, 1.6-8.7, p <.003) remained significant contributors to the model. Language (p<.05), attention (p<.05), and delayed recall (p<.001) were the most affected cognitive domains.

SIGNIFICANCE

When taken in small doses, for brief periods as monotherapy, levetiracetam minimally influences cognition. At higher doses, as part of long-term seizure management, in conjunction with multiple ASMs, LEV is associated with cognitive impairment.

Epilepsy and sleep characteristics are associated with diminished 24-h memory retention in older adults with epilepsy

OBJECTIVE

Individuals with epilepsy often have memory difficulties, and older adults with epilepsy are especially vulnerable, due to the additive effect of aging. The goal of this study was to assess factors that are associated with 24-h memory retention in older adults with epilepsy.

METHODS

Fifty-five adults with epilepsy, all aged >50 years, performed a declarative memory task involving the recall of the positions of 15 card pairs on a computer screen prior to a 24-h ambulatory electroencephalogram (EEG). We assessed the percentage of encoded card pairs that were correctly recalled after 24 h (24-h retention rate). EEGs were evaluated for the presence and frequency of scalp interictal epileptiform activity (IEA) and scored for total sleep. Global slow wave activity (SWA) power during non-rapid eye movement sleep was also calculated.

RESULTS

Forty-four participants successfully completed the memory task. Two were subsequently excluded due to seizures on EEG. The final cohort (n = 42) had a mean age of 64.3 ± 7.5 years, was 52% female, and had an average 24-h retention rate of 70.9% ± 30.2%. Predictors of 24-h retention based on multivariate regression analysis when controlling for age, sex, and education included number of antiseizure medications (β = -.20, p = .013), IEA frequency (β = -.08, p = .0094), and SWA power (β = +.002, p = .02).

SIGNIFICANCE

In older adults with epilepsy, greater frequency of IEA, reduced SWA power, and higher burden of antiseizure medications correlated with worse 24-h memory retention. These factors represent potential treatment targets to improve memory in older adults with epilepsy.

Trends in referral patterns to presurgical evaluation at a European reference center

PURPOSE

To determine if growing evidence for epilepsy surgery as an early treatment option is reflected in the decrease of latencies between epilepsy onset and referral for presurgical evaluation METHODS: Retrospective analysis of latencies in 1646 patients (children and adults) from the time of epilepsy diagnosis to first presurgical workup in the period from 1999 to 2019 based on electronic patient charts at a tertiary epilepsy center. Time spans 1999-2009 and 2010-2019, prior to and following the ILAE definition of pharmacoresistance, and the role of etiological factors were assessed.

RESULTS

Over the whole period, the mean latency between diagnosis and a presurgical workup was 15.3 y. There was a significant reduction in the latencies between the periods 1999-2009 (16.9 y) and 2010-2019 (13.4 y), (p < 0.0001). In a linear regression analysis, the latency decreased by 2.6 months/year from 17.4 in 1999 to 13.1 y in 2019 (p < 0.001). Subgroup analyses showed significant decreases in latency to presurgical evaluation in patients with hippocampal sclerosis from 24.4 to 19.5 y, in malformations of cortical development from 16.4 to 13.2 y, and in nonlesional patients from 18.1 to 12.8 y, in contrast to patients with MR evidence for brain tumors with similar latencies across time (10.5 vs. 9.5 y, n.s.).

CONCLUSION

The reduction of the time span to a first presurgical evaluation was highly significant over time, yet moderate in its degree. Overall, the aim of early diagnostic evaluation for epilepsy surgery options after established pharmacoresistance was only achieved for a minority of patients.

Cognitive Impairment in MRI-Negative Epilepsy: Relationship between Neurophysiological and Neuropsychological Measures

BACKGROUND

Epileptic patients frequently encounter cognitive impairment. Functions that are mostly affected involve memory, attention, and executive function; however, this is mainly dependent on the location of the epileptic activity. The aim of the present study is to assess cognitive functions in MRI-negative epilepsy patients by means of neurophysiological and neuropsychological measures, as well as study the concept of transient cognitive impairment in patients with epileptiform discharges during EEG acquisition.

METHODS

The patients were enrolled from an outpatient Epilepsy/Clinical Neurophysiology clinic over a time period of 6 months. The study sample comprised 20 MRI-negative epilepsy patients (mean age ± standard deviation (SD), 30.3 ± 12.56 years; age range, 16-60 years; average disease duration, 13.95 years) and 10 age-matched controls (mean age ± SD, 24.22 ± 15.39 years), who were also education-matched (p > 0.05). Patients with epileptogenic lesions were excluded from the study. Informed consent was obtained from all subjects involved in the study. Auditory ERPs and the cognitive screening tool EpiTrack were administered to all subjects.

RESULTS

Latencies of P300 and slow waves were prolonged in patients compared to controls (p < 0.05). The ASM load and patients' performance in the EpiTrack maze subtest were the most significant predictors of P300 latency. A decline in the memory, attention, and speed of information processing was observed in patients with cryptogenic epilepsy compared to age-matched controls, as reflected by P300 latency and EpiTrack scores.

Facial Emotion Recognition in Patients with Juvenile Myoclonic Epilepsy

Previous studies have found facial emotion recognition (FER) impairments in individuals with epilepsy. While such deficits have been extensively explored in individuals with focal temporal lobe epilepsy, studies on individuals with generalized epilepsies are rare. However, studying FER specifically in individuals with juvenile myoclonic epilepsy (JME) is particularly interesting since they frequently suffer from social and neuropsychological difficulties in addition to epilepsy-specific symptoms. Furthermore, recent brain imaging studies have shown subtle microstructural alterations in individuals with JME. FER is considered a fundamental social skill that relies on a distributed neural network, which could be disturbed by network dysfunction in individuals with JME. This cross-sectional study aimed to examine FER and social adjustment in individuals with JME. It included 27 patients with JME and 27 healthy controls. All subjects underwent an Ekman-60 Faces Task to examine FER and neuropsychological tests to assess social adjustment as well as executive functions, intelligence, depression, and personality traits. Individuals with JME performed worse in global FER and fear and surprise recognition than healthy controls. However, probably due to the small sample size, no significant difference was found between the two groups. A potential FER impairment needs to be confirmed in further studies with larger sample size. If so, patients with JME could benefit from addressing possible deficits in FER and social difficulties when treated. By developing therapeutic strategies to improve FER, patients could be specifically supported with the aim of improving social outcomes and quality of life.

Investigating the Impact of Epilepsy on Cognitive Function: A Narrative Review

It has been noted that people who have epilepsy have an increased propensity for cognitive dysfunction. We explored 25 relevant articles on PubMed and Cochrane Library after implementing inclusion criteria. Different factors have been postulated and studied that may cause cognitive dysfunction in these patients; structural brain abnormalities, polypharmacy of antiepileptic medication, and neuropsychiatric disorders are the most common causes. Cognitive assessments such as Montreal Cognitive Assessment (MOCA) and Mini-Mental State Exam (MMSE) are the mainstay tools used to diagnose the degree of cognitive decline, and alterations in EEG (electroencephalogram) parameters have also been noted in people with cognitive decline. The mechanisms and treatments for cognitive decline are still being studied, while attention has also been directed toward preventive and predictive methods. Early detection and treatment of cognitive impairment can help minimize its impact on the patient's quality of life. Regular cognitive assessments are essential for epileptic patients, particularly those on multiple antiepileptic drugs. While proper management of epilepsy and related comorbidities would reduce cognitive decline and improve the overall quality of life for people with epilepsy.

Altered topological properties and their relationship to cognitive functions in unilateral temporal lobe epilepsy

OBJECTIVE

To investigate abnormalities in topological properties in unilateral temporal lobe epilepsy (TLE) with hippocampal sclerosis and their correlations with cognitive functions.

METHODS

Thirty-eight patients with TLE and 19 age- and sex-matched healthy controls (HCs) were enrolled in this research and underwent resting-state functional magnetic resonance imaging (fMRI) examinations. Whole-brain functional networks of participants were constructed based on the fMRI data. Topological characteristics of the functional network were compared between patients with left and right TLE and HCs. Correlations between altered topological properties and cognitive measurements were explored.

RESULTS

Compared with the HCs, patients with left TLE showed decreased clustering coefficient, global efficiency, and local efficiency (E_loc), and patients with right TLE showed decreased E_loc. We found altered nodal centralities in six regions related to the basal ganglia (BG) network or default mode network (DMN) in patients with left TLE and those in three regions related to reward/emotion network or ventral attention network in patients with right TLE. Patients with right TLE showed higher integration (reduced nodal shortest path length) in four regions related to the DMN and lower segregation (reduced nodal local efficiency and nodal clustering coefficient) in the right middle temporal gyrus. When comparing left TLE with right TLE, no significant differences were detected in global parameters, but the nodal centralities in the left parahippocampal gyrus and the left pallidum were decreased in left TLE. The E_loc and several nodal parameters were significantly correlated with memory functions, duration, national hospital seizure severity scale (NHS3), or antiseizure medications (ASMs) in patients with TLE.

CONCLUSIONS

The topological properties of whole-brain functional networks were disrupted in TLE. Networks of left TLE were characterized by lower efficiency; right TLE was preserved in global efficiency but disrupted in fault tolerance. Several nodes with abnormal topological centrality in the basal ganglia network beyond the epileptogenic focus in the left TLE were not found in the right TLE. Right TLE had some nodes with reduced shortest path length in regions of the DMN as compensation. These findings provide new insights into the effect of lateralization on TLE and help us to understand the cognitive impairment of patients with TLE.

Deep Brain Stimulation of the Anterior Nucleus of the Thalamus in Drug-Resistant Epilepsy in the MORE Multicenter Patient Registry

BACKGROUND AND OBJECTIVES

The efficacy of deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) in patients with drug-resistant epilepsy (DRE) was demonstrated in the double-blind Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy randomized controlled trial. The Medtronic Registry for Epilepsy (MORE) aims to understand the safety and longer-term effectiveness of ANT DBS therapy in routine clinical practice.

METHODS

MORE is an observational registry collecting prospective and retrospective clinical data. Participants were at least 18 years old, with focal DRE recruited across 25 centers from 13 countries. They were followed for at least 2 years in terms of seizure frequency (SF), responder rate (RR), health-related quality of life (Quality of Life in Epilepsy Inventory 31), depression, and safety outcomes.

RESULTS

Of the 191 patients recruited, 170 (mean [SD] age of 35.6 [10.7] years, 43% female) were implanted with DBS therapy and met all eligibility criteria. At baseline, 38% of patients reported cognitive impairment. The median monthly SF decreased by 33.1% from 15.8 at baseline to 8.8 at 2 years (p < 0.0001) with 32.3% RR. In the subgroup of 47 patients who completed 5 years of follow-up, the median monthly SF decreased by 55.1% from 16 at baseline to 7.9 at 5 years (p < 0.0001) with 53.2% RR. High-volume centers (>10 implantations) had 42.8% reduction in median monthly SF by 2 years in comparison with 25.8% in low-volume center. In patients with cognitive impairment, the reduction in median monthly SF was 26.0% by 2 years compared with 36.1% in patients without cognitive impairment. The most frequently reported adverse events were changes (e.g., increased frequency/severity) in seizure (16%), memory impairment (patient-reported complaint, 15%), depressive mood (patient-reported complaint, 13%), and epilepsy (12%). One definite sudden unexpected death in epilepsy case was reported.

DISCUSSION

The MORE registry supports the effectiveness and safety of ANT DBS therapy in a real-world setting in the 2 years following implantation.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that ANT DBS reduces the frequency of seizures in patients with drug-resistant focal epilepsy.

TRIAL REGISTRATION INFORMATION

MORE ClinicalTrials.gov Identifier: NCT01521754, first posted on January 31, 2012.

The who, what, when and why of cognitive difficulties in epilepsy

Cognitive complaints are very common in people diagnosed with epilepsy. These difficulties are often another manifestation of the same pathology responsible for seizures. They can be further exacerbated by treatments aimed at seizure control. Other common comorbidities of epilepsy such as low mood and elevated anxiety can also contribute to cognitive complaints. There is surprisingly little overlap between memory complaints and performance on formal memory tests in this population. This article examines the multifactorial and heterogeneous nature of cognitive difficulties in epilepsy and makes the case for the provision of basic psychoeducation as the foundation for all interventions aimed at ameliorating these difficulties in this patient population.

Could thalamic biochemical changes correlate to cognitive impairment in idiopathic generalized epilepsy?

Background

The thalamus is crucial in the development of idiopathic generalized epilepsy (IGE), which could lead to cognitive dysfunctions, according to data from neuropsychology and advanced neuroimaging investigations. This research aimed to measure the metabolic changes in the thalamus and to assess if could be contributed to cognitive impairment in IGE patients. Thirty IGE patients and thirty healthy volunteers with matched ages, genders, and educational levels participated in this cross-sectional case–control research. The IGE patients and controls were evaluated neuropsychologically using Intelligence Quotient (IQ) to assess general cognitive ability, Digit span for attention, Wechsler memory scale (WMS) for verbal memory, cube drawing test for visuospatial memory, Trail making test for executive functions, and Controlled Oral Word Association test (COWAT) for verbal fluency and quantitative multi-voxel MR spectroscopy (MRS) measurements of N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), NAA/Cr, NAA/Cho and Cho/Cr ratios at 1.5 T scanner. The voxels were located over the right and left thalamus.

Results

The IGE patients showed worse cognitive performance in IQ, attention, executive function, and verbal and visuospatial memory domains compared to the controls. The IGE patients exhibited a significantly decrease NAA in the right thalamus (p = 0.004) and a lower NAA/Cr ratio in the left thalamus (p = 0.01). the mean thalamus NAA level exhibited a positive correlation with CDT (r = 0.45, p = P = 0.01), and WMS-R (r = 0.39, p = 0.03) and a negative correlation with trail-making A test (r = 0.42, P = 0.01).

Conclusions

it was concluded that IGE patients exhibited poor cognition which could be attributed to thalamic neurometabolic changes due to impaired thalamic cortical circuits.

The relationship between memory and quality of life is mediated by trait anxiety in patients with temporal lobe epilepsy

PURPOSE

Memory deficits are very frequent in patients with drug-resistant epilepsy, but they predict a small proportion of variance of their quality of life (QOL) in previous studies, possibly due to the lack of consideration of mediating factors of this relationship. This study aimed to examine whether trait anxiety mediates the relationship between memory and QOL in this population, controlling the influence of demographic and seizure-related factors.

METHODS

In this cross-sectional study, 119 adults with drug-resistant temporal lobe epilepsy (TLE) underwent a neuropsychological evaluation, in which memory, anxiety, and QOL were assessed.

RESULTS

In the total sample, better delayed memory had an effect on better QOL indirectly through lower trait anxiety (B = 0.13, SE = 0.06, p = 0.04, ab_cs = 0.13; κ² = 0.18; PM_ind = 0.76). Additionally, delayed memory has not a direct association with QOL (B = 0.04, SE = 0.09, p = 0.64, Cohen's f ² = 0.005; PM_dir = 0.24), and the total effect of delayed memory on QOL tended to reach statistical significance (B = 0.17, SE = 0.10, p = 0.08). The proposed mediation model yielded excellent fit (CFI = 1.00, RMSEA = 0.0001, SRMR = 0.009, and χ² (1) = 0.50, p = 0.48) and explained 38% of the variance of QOL.

CONCLUSION

These findings suggest that trait anxiety is an important factor in understanding the relationship between memory and QOL in patients with TLE, considering the influence of demographic and seizure-related variables, and may have relevant implications for decision-making in this population.

Traditional and Innovative Anti-seizure Medications Targeting Key Physiopathological Mechanisms: Focus on Neurodevelopment and Neurodegeneration

Despite the wide range of compounds currently available to treat epilepsy, there is still no drug that directly tackles the physiopathological mechanisms underlying its development. Indeed, antiseizure medications attempt to prevent seizures but are inefficacious in counteracting or rescuing the physiopathological phenomena that underlie their onset and recurrence, and hence do not cure epilepsy. Classically, the altered excitation/inhibition balance is postulated as the mechanism underlying epileptogenesis and seizure generation. This oversimplification, however, does not account for deficits in homeostatic plasticity resulting from either insufficient or excessive compensatory mechanisms in response to a change in network activity. In this respect, both neurodevelopmental epilepsies and those associated with neurodegeneration may share common underlying mechanisms that still need to be fully elucidated. The understanding of these molecular mechanisms shed light on the identification of new classes of drugs able not only to suppress seizures, but also to present potential antiepileptogenic effects or "disease-modifying" properties.

Association between road traffic accidents and drugs belonging to the antiseizure medications class: A pharmacovigilance analysis in VigiBase

AIMS

Due to their central mechanism of action, antiseizure medications (ASMs) could lead to adverse effects likely to impair driving skills. Their extended use to neuropsychiatric disorders makes it a class of drugs to monitor for their road traffic accidental (RTA) potential. We aimed to assess the reporting association between ASMs and RTAs using the World Health Organization pharmacovigilance database (VigiBase).

METHODS

We performed a disproportionality analysis to compute adjusted reporting odds ratios to evaluate the strength of reporting association between ASMs and RTAs. A univariate analysis using the reporting odds-ratio was used to assess drug-drug interactions between ASMs and RTAs.

RESULTS

There were 1 341 509 reports associated with at least 1 ASM in VigiBase of whom 2.91‰ were RTAs reports. Eight ASMs were associated with higher reporting of RTAs compared to others (ranging from 1.35 [95% confidence interval 1.11-1.64] for lamotrigine to 4.36 [95% confidence interval 3.56-5.32] for cannabis). Eight significant drug-drug interactions were found between ASMs and the onset of RTA, mainly involving CYP450 induction.

CONCLUSION

A significant safety signal between RTAs and some ASMs was identified. Association of several ASMs might further increase the occurrence of RTA. ASMs prescription in patients with identified risk factors of RTA should be considered with caution. Study number: ClinicalTrials.gov, NCT04480996.

Treatment-emergent adverse events and antiseizure medication actual drug load

OBJECTIVE

The correlation between treatment-emergent adverse events (TEAE) and antiseizure medication (ASM) drug load is a controversial topic. Previous studies used daily defined dosage (DDD) to measure drug load. We aim to assess if ASM adjusted to body weight and plasma levels were associated with TEAE.

METHODS

We analyzed clinical visits of a trial on therapeutic drug monitoring in outpatients with epilepsy. TEAE, treatment, and its changes, as well as ASM plasma levels, were recorded at each visit. Each medication level was stratified according to its position in relation to its proposed reference range (below, in the lower half, upper half, or above).

RESULTS

We analyzed 424 visits (151 participants). Treatment-emergent adverse events were reported in 84 (20%) visits. There was no significant difference when comparing visits with TEAE with those without TEAE in terms of ASM drug load (calculated with DDD), corrected for body weight, their changes since the last visit, as well as summed plasma levels compared to reference ranges.

SIGNIFICANCE

Actual drug load seems not to represent a major determinant of TEAE recorded during routine visits, even when accounting thoroughly for the patient's exposure to the treatment. The use of structured questionnaires and neuropsychometric tests may assess more accurately the potential consequences of drug loads.

Drug resistance in idiopathic generalized epilepsies: Evidence and concepts

Although approximately 10%-15% of patients with idiopathic generalized epilepsy (IGE)/genetic generalized epilepsy remain drug-resistant, there is no consensus or established concept regarding the underlying mechanisms and prevalence. This review summarizes the recent data and the current hypotheses on mechanisms that may contribute to drug-resistant IGE. A literature search was conducted in PubMed and Embase for studies on mechanisms of drug resistance published since 1980. The literature shows neither consensus on the definition nor a widely accepted model to explain drug resistance in IGE or one of its subsyndromes. Large-scale genetic studies have failed to identify distinct genetic causes or affected genes involved in pharmacokinetics. We found clinical and experimental evidence in support of four hypotheses: (1) "network hypothesis"-the degree of drug resistance in IGE reflects the severity of cortical network alterations, (2) "minor focal lesion in a predisposed brain hypothesis"-minor cortical lesions are important for drug resistance, (3) "interneuron hypothesis"-impaired functioning of γ-aminobutyric acidergic interneurons contributes to drug resistance, and (4) "changes in drug kinetics"-genetically impaired kinetics of antiseizure medication (ASM) reduce the effectiveness of available ASMs. In summary, the exact definition and cause of drug resistance in IGE is unknown. However, published evidence suggests four different mechanisms that may warrant further investigation.

Neuropsychological performance in patients with focal drug-resistant epilepsy and different factors that affect their performance

Background

Drug-resistant epilepsy (DRE) accounts for nearly 30% of patients with epilepsy, which is associated with high incidence of cognitive comorbidity. The aim of this work was to study the role of neuropsychological assessment in patients with epilepsy, and different factors that affect their performance in patients with multiple factors (focal onset DRE).

Methods

118 patients were recruited from Kasr Alainy hospital, epilepsy outpatient clinic with focal DRE. The patients’ demographic and clinical data were collected, Electroencephalograph (EEG) interictal/ictal (when available), and brain imaging (MRI epilepsy protocol). Neuropsychological assessment by Wechsler Adult Intelligence Scale (WAIS-IV), proposed neurocognitive assessment battery and mood assessment was done. Their performance in neuropsychological assessment was correlated with the collected data. Concordance between different assessment modalities and brain lesion were done.

Results

Among recruited patients, 67.3% of patients showed Full-scale Intelligence Quotient (FSIQ) was less than average. FSIQ score significantly correlated with years of education, and number of anti-seizure medications (ASMs). Neurocognitive assessment battery could achieve cognitive profile of the patients but with poor lateralizing value. Executive function was the most affected cognitive domain. History of status epilepticus significantly affect FSIQ and executive function performance. Fifty-six percent of patients had depression. Among the analyzed factors, FSIQ and lesional brain imaging significantly affected neurocognitive performance of studied patients. Clinical semiology had better concordance in lateralization (74.7%) and localization (69.5%) with brain imaging compared to ictal EEG. Among patients who had ictal EEG recording, 36.4% patients (25% were temporal lobe) had complete concordance, while 38.6% patients had partial concordance.

Conclusions

Among analyzed factors, FSIQ was the most significant determinant of studied population’s neurocognitive performance. Clinical semiology were the best correlated with brain lesion. Complete concordance was best detected at the temporal lobe.