Monitoring the cognitive effects of antiepileptic pharmacotherapy--approaching the individual patient

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.

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.

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.

Value of drug level concentrations of brivaracetam, lacosamide, and perampanel in care of people with epilepsy

OBJECTIVE

The aim of this study was to determine whether clinical efficacy and reported adverse effects (AEs) of the newer antiseizure medications (ASMs) brivaracetam (BRV), lacosamide (LCM), and perampanel (PER) have been associated with plasma levels of these ASMs. We also investigated whether plasma levels outside the reference range has led to dose adjustments.

METHODS

Plasma levels of 300 people with epilepsy (PWE) seen at our tertiary epilepsy center were determined by liquid chromatography-tandem mass spectrometry. PWE received BRV (n = 100), LCM (n = 100), or PER (n = 100), in most cases in polytherapy. Demographic and clinical data were retrospectively analyzed and related to plasma levels. Clinical efficacy of BRV, LCM, or PER was assessed retrospectively by comparing seizure frequency at the time of current blood draw with seizure frequency at the time of first administration. AEs were also recorded and, if reported, compared retrospectively with the time of first administration.

RESULTS

No significant associations were found between plasma levels of BRV, LCM, or PER and seizure freedom (BRV, p = 1.000; LCM, p = .243; PER, p = .113) or responder status (BRV, p = .118; LCM, p = .478; PER, p = .069) at presentation. There was also no pattern between plasma levels and the occurrence of AEs. In the majority of cases, drug levels outside the reference ranges have not led to adjustments in the daily doses of BRV (93.5%), LCM (93.9%), or PER (89.1%).

SIGNIFICANCE

Plasma levels at a given time point did not allow conclusions to be drawn about seizure control or the occurrence of AEs. Our findings indicate that efficacy and tolerability cannot be predicted based on averaged data from a single plasma measurement due to high interindividual variability. Instead, individual reference values should be established when sufficient clinical data are available, in line with the 2008 International League Against Epilepsy position paper on therapeutic drug monitoring.

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.

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.

Hippocampal ΔFosB expression is associated with cognitive impairment in a subgroup of patients with childhood epilepsies

Epilepsy is a chronic neurological disorder characterized by recurrent seizures, and is often comorbid with other neurological and neurodegenerative diseases, such as Alzheimer's disease (AD). Patients with recurrent seizures often present with cognitive impairment. However, it is unclear how seizures, even when infrequent, produce long-lasting deficits in cognition. One mechanism may be seizure-induced expression of ΔFosB, a long-lived transcription factor that persistently regulates expression of plasticity-related genes and drives cognitive dysfunction. We previously found that, compared with cognitively-intact subjects, the activity-dependent expression of ΔFosB in the hippocampal dentate gyrus (DG) was increased in individuals with mild cognitive impairment (MCI) and in individuals with AD. In MCI patients, higher ΔFosB expression corresponded to lower Mini-Mental State Examination scores. Surgically resected DG tissue from patients with temporal lobe epilepsy also showed robust ΔFosB expression; however, it is unclear whether ΔFosB expression also corresponds to cognitive dysfunction in non-AD-related epilepsy. To test whether DG ΔFosB expression is indicative of cognitive impairment in epilepsies with different etiologies, we assessed ΔFosB expression in surgically-resected hippocampal tissue from 33 patients with childhood epilepsies who had undergone Wechsler Intelligence Scale for Children (WISC) testing prior to surgery. We found that ΔFosB expression is inversely correlated with Full-Scale Intelligence Quotient (FSIQ) in patients with mild to severe intellectual disability (FSIQ < 85). Our data indicate that ΔFosB expression corresponds to cognitive impairment in epilepsies with different etiologies, supporting the hypothesis that ΔFosB may epigenetically regulate gene expression and impair cognition across a wide range of epilepsy syndromes.

A review of cognitive and behavioral outcomes of Brivaracetam

Anti-seizure medications (ASMs) can cause cognitive or behavioral adverse drug reactions, which is an important consideration when selecting an appropriate ASM. Brivaracetam (BRV) is a newer synaptic vesicle protein 2A ligand, which is expected to result in fewer neuropsychiatric adverse effects due to its mechanism of action. To understand the impact of BRV on cognition and behavior compared with other ASMs, we conducted a review of the literature using the Cochrane Library, PubMed/MEDLINE, and Embase. After the screening process, a total of two animal studies, one randomized controlled trial, one pooled analysis of clinical trials, one controlled study, and nine observational studies were included. The animal studies showed that BRV did not worsen cognitive or behavioral performance in rodents. The human studies showed that BRV was associated with fewer cognitive adverse events compared with other second- or third-generation ASMs. In addition, BRV was less associated with behavioral disturbance than levetiracetam. In summary, this review revealed that BRV has a limited impact on cognition and behavior. For patients who are intolerant to levetiracetam and have levetiracetam-related behavioral side effects, switching to BRV could be beneficial. However, heterogeneity between studies resulted in low-quality of evidence, and further trials are needed to confirm the findings.

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.

Gene therapy for epilepsy

On-demand inhibition of neuronal activity reduced spontaneous seizures in mice

The burden of epilepsy and unmet need in people with focal seizures

BACKGROUND

Epilepsy is one of the most common neurological conditions worldwide. As a chronic condition, epilepsy imposes a significant burden on people with epilepsy and society. We aimed to assess the burden and unmet need of individuals with epilepsy and their caregivers, focusing on focal seizures, the main type of seizure in adults and children.

METHODS

A targeted evidence review of the burden of epilepsy, focusing on focal seizures, was conducted to identify articles reporting: epidemiology, mortality, morbidity, quality of life (QoL), and costs.

RESULTS

Focal seizures affect up to ∼61% of people with epilepsy. They are associated with an increased risk of injury and premature death than the general population. People with epilepsy also have high comorbidity, particularly depression, anxiety, and cognitive impairments. Higher seizure frequency, adverse treatment events, and employment concerns reduce QoL. A reduction in caregivers' QoL is also often reported. Epilepsy requires long-term treatment accounting for high individual costs. Hospitalizations and antiseizure medications (ASMs) are the leading cost drivers of inpatient management and indirect costs with high unemployment rates, particularly in drug-resistant populations. Despite the advent of new treatments, a high unmet need remains unaddressed; approximately 40% of people with epilepsy are drug-resistant, further increasing the risks associated with epilepsy.

CONCLUSIONS

Our findings highlight a substantial burden of illness and unmet needs in individuals with focal seizures, especially those with drug-resistant epilepsy. Suboptimal treatment options negatively impact QoL and, consequently, a sizeable economic burden indicating the need for new treatments and prioritizing this condition.

Effect of Anti-seizure Medications on Functional Anatomy of Language: A Perspective From Language Functional Magnetic Resonance Imaging

Background

In epilepsy, cognitive difficulties are common, partly a consequence of anti-seizure medications (ASM), and cognitive side-effects are often considered to be more disabling than seizures and significantly affect quality of life. Functional MRI during verbal fluency tasks demonstrated impaired frontal activation patterns and failed default mode network deactivation in people taking ASM with unfavourable cognitive profiles. The cognitive effect of ASMs given at different dosages in monotherapy, or in different combinations, remains to be determined.

Methods

Here, we compared the effects of different drug loads on verbal fluency functional MRI (fMRI) in people (i) taking dual therapy of ASMs either considered to be associated with moderate (levetiracetam, lamotrigine, lacosamide, carbamazepine/oxcarbazepine, eslicarbazepine, valproic acid; n = 119, 56 females) or severe (topiramate, zonisamide) side-effects; n = 119, 56 females), (ii) taking moderate ASMs in either mono-, dual- or triple-therapy (60 subjects in each group), or (iii) taking different dosages of ASMs with moderate side-effect profiles (n = 180). “Drug load” was defined as a composite value of numbers and dosages of medications, normalised to account for the highest and lowest dose of each specific prescribed medication.

Results

In people taking “moderate” ASMs (n = 119), we observed higher verbal-fluency related to left inferior frontal gyrus and right inferior parietal fMRI activations than in people taking “severe” ASMs (n = 119). Irrespective of the specific ASM, people on monotherapy (n = 60), showed greater frontal activations than people taking two (n = 60), or three ASMs (n = 60). People on two ASMs showed less default mode (precuneus) deactivation than those on monotherapy. In people treated with “moderate” ASMs (n = 180), increased drug load correlated with reduced activation of language-related regions and the right piriform cortex.

Conclusion

Our study delineates the effects of polytherapy and high doses of ASMs when given in monotherapy on the functional anatomy of language. Irrespective of the cognitive profile of individual ASMs, each additional ASM results in additional alterations of cognitive activation patterns. Selection of ASMs with moderate cognitive side effects, and low doses of ASMs when given in polytherapy, could reduce the cognitive effect.

Cognitive reawakening and improved quality of life achieved after discontinuing 16 years of anti-seizure treatment with topiramate

A 42-year-old female patient with epilepsy and a co-morbid migraine suffered from the severe cognitive side effects of topiramate (TPM) for more than 16 years with detrimental consequences for her daily functioning, career, and social interaction. Even a prodromal stage of dementia was suggested, giving rise to fears of developing a neurodegenerative disease. Recently, cognitive monitoring of attention and executive function before and after withdrawal of TPM revealed a significant recovery from the severe negative cognitive side effects of the long-standing and inefficacious antiseizure medication (ASM). Whereas the side effects were reversible after cessation, their consequences for the patient`s biography were permanent. A considerable increase in quality of life, however, was observed without TPM and family members were impressed by the improvements. This case illustrates the potentially severe consequences of negative cognitive side effects which affect daily functioning, career and social life, thus underscoring the importance of being knowledgeable of the potential cognitive risks when prescribing an ASM. Because cognitive side effects may not depend solely on ASM choice and drug load, but also on individual idiosyncratic intolerances, and patients might stay on their treatment for many years, cognitive monitoring is highly recommended.

Evaluation of a Rapid Topiramate Titration Scheme for the Early Detection of Cognitive Side Effects

BACKGROUND

Topiramate (TPM) is effective for treating epilepsy, but executive dysfunction is a common side effect that could significantly affect everyday life. Additionally, previous studies have suggested that patients might be unaware of these changes.

OBJECTIVE

To evaluate a rapid TPM titration scheme for the early detection of adverse cognitive side effects.

METHODS

In this retrospective study, we assessed changes in objective cognitive performance (EpiTrack^®) after rapidly titrating TPM (50 mg per day during an inpatient stay) in 49 epilepsy patients and compared those results with an outpatient control group that underwent the recommended standard titration (n = 23 with 25-50 mg per week).

RESULTS

Using Bayesian statistics, analyses revealed decisive evidence of a negative effect on cognitive performance when TPM was introduced (BF 31480000000) independent of the titration speed (BF 0.739). When using a fast titration rate, deficits in executive function increased from a baseline of 53.1 to 73.5% at follow-up, and 55.1% experienced a statistically significant intraindividual decline. When using the standard titration scheme, impairments increased from 52.2 to 65.2%, with an intraindividual deterioration found in 52.2% of the patients.

CONCLUSION

Physicians might be able to detect adverse cognitive side effects sooner in epilepsy patients if TPM is administered using a faster titration rate while applying repeated cognitive assessments within days. This approach might help prevent any unnoticed intolerance and eventual negative consequences for the patient. Therefore, we recommend monitoring early on for adverse changes instead of withholding a potentially effective treatment option because of anticipated side effects.

The impact of perampanel on cognition: A systematic review of studies employing standardized tests in patients with epilepsy

This systematic review was conducted to reveal the cognitive effects of perampanel (PER) as assessed by objective standardized neuropsychological measures in patients with epilepsy. A systematic literature search was performed in PubMed. In addition we cross-checked a list of relevant studies (based on a ProQuest search) provided by Eisai GmbH. Eligibility criteria were (1) group studies reporting the cognitive outcome of treatment with PER in patients with epilepsy (2) which employed objective cognitive tests and (3) were published in English. Of the 56 initially retrieved records, 9 eligible studies were included in the qualitative synthesis. Two studies were based on the very same sample. Altogether the included studies analyzed a total of 241 patients (46% pediatric) with adjunctive PER. All studies were longitudinal with assessments before and after introduction of PER (up to 5 follow-ups and observation intervals of up to 1 year). Two studies were retrospective, 6 lacked a control condition. Neuropsychological assessments varied in extent and test selection. Overall no systematic cognitive deteriorations or improvements after introduction of PER have been reported across the analyzed studies. The only randomized placebo-controlled trial found a transient worsening in attention and speed of memory at the 19-week follow-up, and in addition a late decline in another parameter of attention at the final 52-week follow-up. This systematic review on the objective cognitive effects of PER suggests an overall neutral cognitive profile of PER with no systematic cognitive deteriorations or improvements. More controlled studies on the cognitive effects of PER would be appreciated.

Neurobehavioural comorbidities of epilepsy: towards a network-based precision taxonomy

Cognitive and behavioural comorbidities are prevalent in childhood and adult epilepsies and impose a substantial human and economic burden. Over the past century, the classic approach to understanding the aetiology and course of these comorbidities has been through the prism of the medical taxonomy of epilepsy, including its causes, course, characteristics and syndromes. Although this 'lesion model' has long served as the organizing paradigm for the field, substantial challenges to this model have accumulated from diverse sources, including neuroimaging, neuropathology, neuropsychology and network science. Advances in patient stratification and phenotyping point towards a new taxonomy for the cognitive and behavioural comorbidities of epilepsy, which reflects the heterogeneity of their clinical presentation and raises the possibility of a precision medicine approach. As we discuss in this Review, these advances are informing the development of a revised aetiological paradigm that incorporates sophisticated neurobiological measures, genomics, comorbid disease, diversity and adversity, and resilience factors. We describe modifiable risk factors that could guide early identification, treatment and, ultimately, prevention of cognitive and broader neurobehavioural comorbidities in epilepsy and propose a road map to guide future research.

Effect of long-term administration of clonazepam, carbamazepine, and valproate on cognitive, psychological, and personality changes in adult epilepsy: a case–control study

Background

Epilepsy can be treated with antiepileptic drugs (AEDs) which may have psychiatric and behavioral side effects. Additionally, the availability of new AEDs has increased, and our understanding of variability to combinations of several AEDs has evolved. Based on the treatment outcomes of carbamazepine, valproate, and clonazepam, this study aims to compare the cognitive function, personality, and psychological issues associated with these drugs and evaluate seizure-related factors related to them. Only 139 participants were included. Clonazepam was used as an add-on antiepileptic drug. Participants were categorized into five groups: group 1, carbamazepine; group 2, valproate; group 3, carbamazepine and clonazepam; group 4, valproate and clonazepam; and group 5, epileptic patients without AED. All participants were assessed using the Wechsler Adult Intelligence Scale (WAIS), Structured Interview for the Five-Factor Personality Model (SIFFM), Hamilton Anxiety and Depression Rating Scale, and Minnesota Multiphasic Personality Inventory-2 (MMPI-2).

Results

In the WAIS, group 1 had the worst mean of verbal intelligence quotient (IQ). Moreover, group 3 was more vulnerable in symptomatic response in all subscales of MMPI-2 except the masculinity–femininity subscale and a high percentage in moderate severity of anxiety and depression in the Hamilton scales.

Conclusions

The use of clonazepam and carbamazepine might increase the incidence of behavioral problems especially increased severity of anxiety and depression and decreased performance IQ compared with either clonazepam or carbamazepine alone. Moreover, patients with carbamazepine treatment might have more personality changes and lowered verbal IQ than others.

Predictive factors of postoperative outcome in the elderly after resective epilepsy surgery

OBJECTIVE

To evaluate the efficiency of resective epilepsy surgery (RES) in patients over 50 years and determine prognostic factors.

RESULTS

Over the 147 patients over 50 years (54.9±3.8 years [50-69]) coming from 8 specialized French centres for epilepsy surgery, 72.1%, patients were seizure-free and 91.2% had a good outcome 12 months after RES. Seizure freedom was not associated with the age at surgery or duration of epilepsy. In multivariate analysis, seizure freedom was associated with MRI and neuropathological hippocampal sclerosis (HS) (P=0.009 and P=0.028 respectively), PET hypometabolism (P=0.013), temporal epilepsy (P=0.01). On the contrary, the need for intracranial exploration was associated with a poorer prognosis (P=0.001). Postoperative number of antiepileptic drugs was significantly lower in the seizure-free group (P=0.001). Neurological adverse event rate after surgery was 21.1% and 11.7% of patients had neuropsychological adverse effects overall transient.

CONCLUSIONS

RES is effective procedure in the elderly. Even safe it remains at higher risk of complication and population should be carefully selected. Nevertheless, age should not be considered as a limiting factor, especially when good prognostic factors are identified.

Drug load and memory during intracarotid amobarbital procedure in epilepsy

BACKGROUND

Anti-seizure medications (ASMs) have been related to poor cognitive function, but their relationship with intracarotid amobarbital procedure (IAP) results remains unclear.

AIMS OF THE STUDY

To elucidate whether the number and drug load of ASMs are associated with memory scores of the IAP and the neuropsychological assessment.

METHODS

Fifty-nine adult patients with drug-resistant epilepsy (mean age = 36.1, SD = 11.6) underwent bilateral IAP (with drawings and words as memory items) and a neuropsychological assessment to assess the risk of post-surgical memory decline. Total ASM drug load was calculated by summing the daily dose/defined daily dose ratio of every ASM of each patient. Pearson's correlations and hierarchical regressions were computed.

RESULTS

Total IAP memory score was associated with total ASM drug load (r = -0.30, p = 0.02) and seizure frequency (r = -0.25, p = 0.05). After controlling clinical variables, total ASM drug load explained 16% of the variance of total IAP memory score. This relationship was especially prominent in patients with left hemisphere focus (r = -0.33, p = 0.04). The number of current ASMs was not related to IAP memory score (r = -0.16, p = 0.24). The number or drug load of ASMs were not related to neuropsychological assessment results (for all, p > 0.07).

CONCLUSIONS

Our findings suggest that total drug load can be a confounding variable in the IAP memory performance that could explain, at least in part, the reverse asymmetries reported in different studies.

Multiple-brain systems dynamically interact during tonic and phasic states to support language integrity in temporal lobe epilepsy

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Unique brain dynamics occur during language task in left temporal lobe epilepsy (TLE).

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Multiple brain systems interact to implement compensated language status in TLE.

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Tonic/rest dynamics exert influence and may prime the level of phasic/task dynamics.

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Multi-network integrations are compensatory in patients with lower language skills.

An epileptogenic focus in the dominant temporal lobe can result in the reorganization of language systems in order to compensate for compromised functions. We studied the compensatory reorganization of language in the setting of left temporal lobe epilepsy (TLE), taking into account the interaction of language (L) with key non-language (NL) networks such as dorsal attention (DAN), fronto-parietal (FPN) and cingulo-opercular (COpN), with these systems providing cognitive resources helpful for successful language performance.

We applied tools from dynamic network neuroscience to functional MRI data collected from 23 TLE patients and 23 matched healthy controls during the resting state (RS) and a sentence completion (SC) task to capture how the functional architecture of a language network dynamically changes and interacts with NL systems in these two contexts.

We provided evidence that the brain areas in which core language functions reside dynamically interact with non-language functional networks to carry out linguistic functions. We demonstrated that abnormal integrations between the language and DAN existed in TLE, and were present both in tonic as well as phasic states. This integration was considered to reflect the entrainment of visual attention systems to the systems dedicated to lexical semantic processing. Our data made clear that the level of baseline integrations between the language subsystems and certain NL systems (e.g., DAN, FPN) had a crucial influence on the general level of task integrations between L/NL systems, with this a normative finding not unique to epilepsy. We also revealed that a broad set of task L/NL integrations in TLE are predictive of language competency, indicating that these integrations are compensatory for patients with lower overall language skills.

We concluded that RS establishes the broad set of L/NL integrations available and primed for use during task, but that the actual use of those interactions in the setting of TLE depended on the level of language skill. We believe our analyses are the first to capture the potential compensatory role played by dynamic network reconfigurations between multiple brain systems during performance of a complex language task, in addition to testing for characteristics in both the phasic/task and tonic/resting state that are necessary to achieve language competency in the setting of temporal lobe pathology. Our analyses highlighted the intra- versus inter-system communications that form the basis of unique language processing in TLE, pointing to the dynamic reconfigurations that provided the broad multi-system support needed to maintain language skill and competency.

Fenfluramine as antiseizure medication for epilepsy

Fenfluramine hydrochloride has classically been described as acting pharmacologically through a serotonergic mechanism. Therefore, it was initially used as an anorectic drug, given that impaired serotonin homeostasis may be associated with increased food intake. Although positive results were documented, cardiovascular concerns resulted in its temporary withdrawal. Nevertheless, a novel role in patients with epilepsy was later suggested by isolated clinical observations. The wide application of genetic testing allowed the classification (predominantly as Dravet syndrome) of patients in whom benefit was seen, while with the development of zebrafish models, its antiepileptic properties were confirmed at a molecular level. Data from randomized clinical trials have shown a beneficial effect of fenfluramine, as an adjunct therapy, on seizure control for children with Dravet syndrome, though there is still uncertainty about the impact on neurodevelopment in these patients. No signs of heart valve disease have been documented to date. Long-term and appropriately designed clinical studies will verify whether fenfluramine is a therapeutic agent of high importance, living up to the promise shown so far. What this paper adds Fenfluramine is a very promising repurposed therapy specifically for seizures in Dravet syndrome. The long-term effect of fenfluramine on neurodevelopmental prognosis requires further investigation.

Prevalence and Factors Influencing Visual Memory Dysfunction among Epilepsy Patients-A Single-Center Study

Background

Epilepsy is associated with cognitive impairment due to the disease itself or side-effects of antiepileptic drugs.

Objective

We aimed to study the prevalence of visual memory dysfunction among epilepsy patients and identify the predictors that could contribute to the impairment.

Materials and Methods

This was a cross-sectional study. We analyzed 250 patients with epilepsy from neurology clinic at our tertiary center. Assessment of visual memory was done using Wechsler Memory Scale-IV (WMS-IV) with scores from subsets of visual reproduction I, II and designs I, II contributing to visual memory index (VMI) score. The correlation between continuous variables was analyzed using Pearson correlation; whereas the VMI scores of different factors were analyzed via a 1-way ANOVA test. The statistical significance was set at P < 0.05.

Results

The prevalence of visual memory dysfunction in our epilepsy population was 37.2%. Analysis of individual predictors showed that older patients, lower educational level, combined generalized and focal types of epilepsy, longer duration of epilepsy, greater number of antiepileptic drugs (AEDs) used, and abnormal neuroimaging contributed to poor visual memory. Multiple logistic regression analysis showed that educational level, types of epilepsy, and the number of AEDs used were significant predictors for visual memory impairment.

Conclusion

Visual memory dysfunction in patients with epilepsy was due to manifold confounding factors. Our findings enabled us to identify patients with visual memory dysfunction and modifiable factors that contribute to it. WMS-IV is a suitable assessment tool to determine visual memory function, which can help clinicians to optimize the patients' treatment.

Neurocognitive Effects of Antiseizure Medications in Children and Adolescents with Epilepsy

Impairments in cognition are common in epilepsy and may be caused or exacerbated by antiseizure medications (ASMs). Positive effects on cognition may also be seen with some ASMs. Cognitive outcomes are of particular concern in children who may be at an increased risk of cognitive adverse effects of treatment. A comprehensive literature search was conducted in PubMed in order to evaluate the evidence for cognitive changes associated with treatment with ASMs in paediatric epilepsy patients. The ASMs considered were those in the current edition of the British National Formulary (BNF). For most ASMs, remarkably few studies providing robust data on cognitive effects in paediatric patients were identified. The available evidence suggests cognitive impairments may be associated with treatment with phenobarbital. Topiramate and phenytoin are also associated with negative effects on cognition, in particular word-finding difficulties and other language deficits with topiramate, but there are few data available specifically on children. Lamotrigine, levetiracetam and fenfluramine are associated with improvements in some cognitive domains, although it is unclear whether these effects are directly attributable to the medications or are a result of improvements in seizures. Neutral effects on cognition (no substantial evidence of worsening) were suggested for carbamazepine, everolimus, lacosamide, oxcarbazepine, perampanel and valproate. There is limited data for cannabidiol, clobazam, eslicarbazepine acetate, ethosuximide, rufinamide, vigabatrin and zonisamide, although the available evidence suggests these drugs are not associated with severe cognitive impairment. There was too little information to reach conclusions about the effects of brivaracetam, felbamate, gabapentin, pregabalin, retigabine, stiripentol or tiagabine.

Associating executive dysfunction with behavioral and socioemotional problems in children with epilepsy. A systematic review

As children with epilepsy may have a number of learning and behavioral problems, it is important that insight into the underlying neurocognitive differences in these children, which may underlie these areas of challenge is gained. Executive function (EF) problems particularly are associated with specific learning abilities as well as behavioral problems. We aim to review systematically the current status of empirical studies on the association between EF problems and behavior and socioemotional problems in children with epilepsy. After search, 26 empirical studies were identified, most of them of moderate quality. Overall, attention problems were the most reported cognitive deficit in test assessment and the most reported problem by parents. In 54% of the studies, children with epilepsy scored below average compared to controls/normative samples on different aspects of EF. Most studies reported behavior problems, which ranged from mild to severe. Forty-two percent of the studies specifically reported relationships between EF deficits and behavioral problems. In the remaining studies, below average neuropsychological functioning seemed to be accompanied by above average reported behavioral problems. The association was most pronounced for cognitive control and attention in relation to externalizing behavior problems. This cognitive control is also associated with social functioning. Relevant epilepsy variables in this relationship were early age at onset and high seizure frequency.Future research should distinguish specific aspects of EF and take age into account, as this provides more insight on the association between EF and behavior in pediatric epilepsy, which makes it possible to develop appropriate and early intervention.

Epilepsy and pregnancy: What should the neurologists do?

Epilepsy is one of the most common chronic disorders affecting women of childbearing age. Unfortunately, many women with epilepsy (WWE) still report not receiving key information about pregnancy. They obviously need information about epilepsy and pregnancy prior to conception with a particular emphasis on effective birth control (i.e. contraception), necessity to plan pregnancy, antiepileptic drugs optimization, and folate supplementation. The risks associated with use of antiepileptic drugs during pregnancy have to be balanced against fetal and maternal risks associated with uncontrolled seizures. This report reviews evidence-based counseling and management strategies concerning maternal and fetal risks associated with seizures, teratogenic risks associated with antiepileptic drug exposure with a special emphasis on developmental and behavioural outcomes of children exposed to intra utero antiepileptic drugs.

EpiTrack is a feasible tool for assessing attention and executive functions in patients with refractory epilepsy

OBJECTIVE

The purpose of this cross-sectional retrospective study was to utilize EpiTrack to assess cognitive performance within the domain of attention and executive functions in patients with refractory epilepsy in consideration for treatment interventions either with antiepileptic drug (AED) changes and/or neuromodulation therapies. We also aimed to identify the relevant clinical and treatment factors possibly affecting EpiTrack performance.

METHODS

The patient group consisted of 95 consecutive refractory epilepsy patients who were evaluated with EpiTrack. Based on their EpiTrack performance, the patients could be categorized as cognitively unimpaired, mildly, or severely impaired. The patients were also divided into three groups based on the planned treatment modification: AED group (n = 38) with only AED treatment, vagal nerve stimulation (VNS) group (n = 40) and deep-brain stimulation (DBS) group (n = 17). However, the effect of planned interventions was not the subject of this study. We retrospectively reviewed the medical records for detailed clinical characterization.

RESULTS

EpiTrack performance was severely impaired in 48 (50.5%), mildly impaired in 22 (23.2%) and unimpaired in 25 (26.3%) of the patients. The DBS group had significantly lower EpiTrack scores (mean (SD) and median, 25.5 (4.81) and 27.0, respectively) compared to the AED group (28.6 (6.2) and 30.0, respectively, p = 0.049). Sixty-three (66.3%) of the whole study population had more than 2 AEDs. When comparing EpiTrack scores between patient groups based on the number of AEDs administered, there was a trend toward better performance in EpiTrack with 2 AEDs as compared to 3-4 AEDs.

CONCLUSIONS

Deficits in attention and executive functions were frequent among patients with refractory epilepsy. Deficits were evident in all three treatment groups being most severe in the DBS group reflecting the patient selection. Furthermore, the effect of AED burden on executive functions was remarkable since two thirds of the patients had more than two AEDs and the deficits were more prominent among those with a higher AED burden. These results highlight the benefits of a feasible screening tool such as EpiTrack for assessing attention and executive functions when optimizing the treatment effects of neurostimulation therapies on cognition, and when evaluating the impacts of the AED burden.

Specific B- and T-cell populations are associated with cognition in patients with epilepsy and antibody positive and negative suspected limbic encephalitis

OBJECTIVE

Neuropsychological impairments are major symptoms of autoimmune limbic encephalitis (LE) epilepsy patients. In LE epilepsy patients with an autoimmune response against intracellular antigens as well as in antibody-negative patients, the antibody findings and magnetic resonance imaging pathology correspond poorly to the clinical features. Here, we evaluated whether T- and B-cells are linked to cognitive impairment in these groups.

METHODS

In this cross-sectional, observational, case-controlled study, we evaluated 106 patients with adult-onset epilepsies with a suspected autoimmune etiology. We assessed verbal and visual memory, executive function, and mood in relation to the presence or absence of known auto-antibodies, and regarding T- and B-cell activity as indicated by flow cytometry (fluorescence-activated cell sorting = FACS, peripheral blood = PB and cerebrospinal fluid = CSF).

RESULTS

56% of the patients were antibody-negative. In the other patients, auto-antibodies were directed against intracellular antigens (GAD65, paraneoplastic: 38%), or cellular surface antigens (LGI1/CASPR2/NMDA-R: 6%). Excluding LGI1/CASPR2/NMDA-R, the groups with and without antibodies did not differ in disease features, cognition, or mood. CD4+ T-cells and CD8+ T-cells in blood and CD4+ T-cells in CSF were prominent in the auto-antibody positive group. Regression analyses indicated the role education, drug load, amygdala and/or hippocampal pathology, and CD4+ T-cells play in verbal memory and executive function. Depressed mood revealed no relation to flow cytometry results.

CONCLUSION

Our results indicate a link between T- and B-cell activity and cognition in epilepsy patients with suspected limbic encephalitis, thus suggesting that flow cytometry results can provide an understanding of cognitive impairment in LE patients with autoantibodies against intracellular antigens.

Cognitive profiles in patients with epileptic and nonepileptic seizures evaluated using a brief cognitive assessment tool

BACKGROUND

There is a need for the development of brief tools to screen for cognitive impairments in epilepsy patients in order to prioritize and direct formal comprehensive cognitive testing. Yet, shorter cognitive screening tools are limited in their breadth of cognitive domains or have not been intensively studied on an epilepsy population. This study used a brief cognitive screening tool in order to compare cognitive profiles between patients with epilepsy and those with nonepileptic seizures.

METHODS

Patients admitted to the Royal Melbourne Hospital video-EEG monitoring unit between 2005 and 2017 were included. Patients were categorized according to seizure etiology (epileptic, psychogenic or other nonepileptic seizures), epilepsy syndrome (focal or generalized; temporal lobe (TLE) or extra-temporal lobe epilepsy (ETLE)), seizure frequency, and anti-seizure medications (ASMs). Attention, visuoconstructional, memory, executive, and language functioning were assessed with the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). General linear mixed models were computed to investigate cognitive profiles according to diagnostic group and other clinicodemographic variables.

RESULTS

800 patients were included in the analysis (61% female and 39 % male, median age 36 years). Patients with both epileptic seizures and psychogenic seizures (n = 25) had the lowest total scores on NUCOG, followed by patients with epileptic seizures (n = 411), psychogenic seizures (n = 185), and nonepileptic seizures (n = 179, p = 0.002). Specifically, patients with epileptic seizures performed worse than those with nonepileptic seizures in the executive, language, and memory domain, and had lower language domain scores than those with psychogenic seizures. Patients with bilateral TLE had poorer performance than those with unilateral TLE, particularly for memory function. Specific ASMs and polypharmacy but not seizure frequency had a negative effect on cognition (p < 0.001). NUCOG scores did not differ between focal and generalized epilepsies, or between TLE and ETLE.

CONCLUSION

The NUCOG differentiated cognitive profiles in patients with uncontrolled seizures due to different etiologies. Bilateral TLE and medication adversely affected cognitive performance, and overall patients with epilepsy performed worse than those with nonepileptic seizures. These results provide further evidence for sensitivity of the NUCOG for detecting cognitive impairment in patients with seizure disorders.

Fatigue and cognitive functions in epilepsy: A review of the literature

Epilepsy is a common neurological disorder affecting people of all ages and inducing cognitive impairments. While research has advanced in terms of neuropsychological enquiries of the various epileptic syndromes, the understanding of more complex and ill-defined phenomena such as fatigue is still unclear for epilepsy. It is suggested that fatigue is not just physical, but there can also be a cognitive element to it. Although studies in other conditions have been able to identify a relationship between fatigue and particular cognitive components, similar evidence is sparse in patients with epilepsy. This review is an attempt to gather, analyze, integrate, and critically discuss available information on fatigue and its rapport with various aspects of epilepsy, particularly focusing on cognition. Future directions are discussed urging researchers to target cognitive components of fatigue.

One-Year Analysis of Risk Factors Associated With Cognitive Impairment in Newly Diagnosed Epilepsy in Adults

Cognitive impairment (CI) occurs in people with epilepsy, affecting their quality of life. This study aimed to identify factors associated with CI in adult patients with newly diagnosed epilepsy. Additionally, we sought to determine whether any particular cognitive function is impaired predominantly by anti-seizure medications or by other factors. We enrolled 229 patients with newly diagnosed epilepsy and 191 participants were followed up for 1 y. We used the Montreal Cognitive Assessment as a tool to quantify CI. The sub-item scores were also collected to assess whether any aspects of CI are predominantly affected by anti-seizure medication treatment. Subjective memory decline due to anti-seizure medications was also recorded. One-hundred-and-two participants (44.5%) had CI onset before anti-seizure medication treatment. Aging, low education level, stroke or brain surgery etiology, and anxious symptoms were identified as risk factors for CI before anti-seizure medications use. Brain surgery for the young, anxious status for the middle-aged, and depressive status for the elderly were risk factors for CI at different ages. The elderly PWE had worse memory than the others. PWE with TLE had worse cognition, especially in memory and naming. The overall impact of anti-seizure medications on cognition was mild. Refractory epilepsy was a predictor of cognitive decline. Subjective memory decline was predicted by high-risk treatment and by a finding of refractory epilepsy. Clarifying the risk factors for CI can help the physician to assess the probable risk of CI for each individual before the start of anti-seizure medication treatment, which may lead to better compliance.

Cognitive disorders in epilepsy II: Clinical targets, indications and selection of test instruments

This is the second of two narrative reviews on cognitive disorders in epilepsy (companion manuscript: Cognitive disorders in epilepsy I: Clinical experience, real-world evidence and recommendations). Its focus is on the clinical targets, indications, and the selection of neuropsychological test instruments. Cognitive assessment has become an essential tool for the diagnosis and outcome control in the clinical management of epilepsy. The diagnostics of basic and higher brain functions can provide valuable information on lateralized and localized brain dysfunctions associated with epilepsy, its underlying pathologies and treatment. In addition to the detection or verification of deficits, neuropsychology reveals the patient's cognitive strengths and, thus, information about the patient reserve capacities for functional restitution and compensation. Neuropsychology is an integral part of diagnostic evaluations mainly in the context of epilepsy surgery to avoid new or additional damage to preexisting neurocognitive impairments. In addition and increasingly, neuropsychology is being used as a tool for monitoring of the disease and its underlying pathologies, and it is suited for the quality and outcome control of pharmacological or other non-invasive medical intervention. This narrative review summarizes the present state of neuropsychological assessments in epilepsy, reveals diagnostic gaps, and shows the great need for education, homogenization, translation and standardization of instruments.

Do interictal EEG findings reflect cognitive function in juvenile myoclonic epilepsy?

PURPOSE

This study investigated the relationship between frontal lobe cognitive function and frontal focal electroencephalography (EEG) findings in patients with juvenile myoclonic epilepsy (JME).

METHODS

The study enrolled 60 patients diagnosed with JME and followed at the Epilepsy Outpatient Clinic of the University of Health Sciences, Bakırkoy Psychiatric Hospital, and 30 healthy volunteers. Demographic and clinical features were recorded. Frontal lobe cognitive functions were tested in both groups. Video-EEG recordings of patients with JME were evaluated. The presence and duration of generalized discharges, the presence and lateralization of focal findings, and the presence of generalized discharges during hyperventilation and photic stimulation were recorded during EEG. Cognitive function test results were compared between the two groups, and the relationship between the EEG findings and cognitive function was investigated.

RESULTS

The study included 35 (58.3%) female and 25 (41.6%) male patients and 17 (56.7%) female and 13 (43.3%) male healthy controls. The mean ages of the group with JME and controls were 28.3 ± 8.6 (16-50) and 31.3 ± 7.9 (17-45) years, respectively. Patients with JME performed more poorly on the frontal lobe cognitive tests than controls (p < 0.05). Patients whose generalized discharges were longer than 1 s performed more poorly on tests evaluating attention and made more perseverative errors (p < 0.05). There was no significant correlation between the presence of focal EEG findings and the scores on frontal lobe cognitive functions tests in the group with JME (p > 0.05).

CONCLUSION

Frontal lobe cognitive functions are affected in patients with JME. The cognitive effects were more pronounced in patients with prolonged generalized discharges on EEG.

AEDs and Cognition: One Small Fish in a Very Large Pond?

[Box: see text]

Perampanel tolerability in children and adolescents with focal epilepsy: Effects on behavior and executive functions

OBJECTIVES

Perampanel (PER) is a noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor antagonist recently approved for focal and generalized epilepsies as an add-on therapy. It is well tolerated and effective as treatment of various pediatric epilepsy syndromes; PER does not seem to negatively affect the cognitive profile of children and adolescents, but its influence on executive functions is still to be assessed.

METHODS

Our sample included 37 children aged 12-18 years, with focal pharmacoresistant epilepsy already in therapy with 2 or 3 antiepileptic drug (AED); PER was added with 1 mg/week increments up to a dose of 2-4 mg/day. Changes in executive functions were assessed by the EpiTrack Junior test. Emotional and behavioral aspects were evaluated through the interview for parents Child Behavior Checklist (CBCL). Both tests were performed before taking PER and after 6 and 12 months of treatment.

RESULTS

After 12 months of PER in 22/30 patients, global score of the EpiTrack Junior test remained almost unchanged; in 7/30 patients, this score improved. The CBCL did not show significant changes in emotional or behavioral problems.

CONCLUSIONS

Adjunctive treatment with PER did not negatively affect executive functions that could also be improved. No emotional/behavioral negative effects have been reported, and this suggests a good tolerability in the middle/long term.

Effects on executive functions of antiepileptic monotherapy in pediatric age

OBJECTIVES

Cognitive abilities and executive functions in children and adolescents are important indicators of quality of life as well as academic and social achievements. Cognitive and executive functioning are often impaired in patients with epilepsy and can be exacerbated by seizures and antiseizure drugs. The aim of our observational retrospective study was to assess executive functioning in patients with pediatric epilepsy, currently taking a single antiseizure medication.

MATERIALS AND METHODS

Records of 172 children and adolescents aged between 6 and 18 years (mean age = 12 ± 3.4 years) with newly diagnosed epilepsy who had not yet commenced an antiepileptic treatment were included in the study. Longitudinal changes in executive functioning were assessed using the EpiTrack Junior test at baseline, before the introduction of antiepileptic monotherapy, and at 3-month, 6-month, and 9-month follow-up visits. All patients commenced a single antiepileptic treatment (levetiracetam n = 54; valproic acid n = 52; ethosuximide n = 20; oxcarbazepine n = 22; carbamazepine n = 24). Age, sex, seizure types, and seizure baseline frequency were also recorded.

RESULTS

Relative to baseline, Epitrack Junior mean scores deteriorated at the 9-month follow-up visit for patients taking valproic acid, ethosuximide, and carbamazepine, but this was only statistically significant for patients taking carbamazepine. In contrast, mean scores improved for subjects taking levetiracetam and oxcarbazepine at the 9-month follow-up visit relative to baseline, but this was only statistically significant for patients taking levetiracetam.

CONCLUSIONS

Levetiracetam was the only antiseizure medication that led to slight improvements in executive functioning; whereas carbamazepine led to deteriorations in cognitive functioning. Further research using double-blinded, placebo-controlled trials are needed to confirm these results.

Effects of Antiepileptic Drug Tapering on Episodic Memory as Measured by Virtual Reality Tests

Antiepileptic drugs impair episodic memory in patients with epilepsy, but this effect has so far only been examined with tests that do not provide first-person experience-an aspect that is crucial for episodic memory. Virtual reality techniques facilitate the development of ecologically valid tests. In the present study, we measure the effect of antiepileptic drug changes in a within-subject design using a virtual reality test in order to provide direct evidence for effects of antiepileptic drugs on episodic memory. Among 106 recruited patients, 97 participated in a virtual reality test up to six times during a 4-day hospitalization, and 78 patients underwent changes in drug load during this period. There were six parallel versions of a virtual town test, with immediate recall and delayed recall after about 12 h. The test requires recall of elements, details, sequence of experience, and egocentric and allocentric spatial memory. We determined drug load by defined daily dose, and compared test performance at lowest antiepileptic drug load to highest antiepileptic drug load. Across the six towns, performance was lower in delayed compared to immediate recall. There was an overall effect of medication when comparing patients taking vs. not taking antiepileptic drugs and/or psychoactive drugs (p = 0.005). Furthermore, there was a within-subject effect of antiepileptic drug load (p = 0.01), indicating lower test performance at higher drug load. There was no effect of gender, daytime, circadian type, depression, seizures, lesions, and epilepsy. For patients with temporal lobe epilepsy, there was no effect of lateralization. The present study provides direct evidence for episodic memory impairment due to antiepileptic drugs, suggesting that a small change in drug load can matter. This study can serve as a proof of principle for the methodology, but a larger sample is needed to examine the differential effects of individual antiepileptic drugs.

Is the computerized assessment of psychomotor speed more sensitive to cognitive effects of antiepileptic pharmacotherapy than tests with a focus on higher-order cognitive processing? Implications for the choice of sensitive test parameters

The study evaluated whether it is psychomotor speed or higher-order cognitive processing which is primarily affected by antiepileptic drug (AED) treatment in epilepsy and whether computerized testing versus paper-pencil testing of executive functions is more sensitive. In this retrospective observational study, 55 patients with epilepsy underwent NeuroCog FX^Ⓡ, a computerized battery assessing "psychomotor speed/alertness" and "cognitive processing" via 8 tasks, and EpiTrack^Ⓡ, a paper-pencil screening of "executive functions and working memory" based on 6 subtests. Test performance was related to the number of drugs and the Defined Daily Dose and the presence/absence of AEDs with known adverse psychotropic effects. EpiTrack^Ⓡ performance correlated with "cognitive processing" of the NeuroCog FX^Ⓡ but not with "psychomotor speed/alertness". Significant correlations with drug load were mainly yielded for EpiTrack^Ⓡ (number of AEDs: r = -0.551, total DDD: r = -0.452) and "cognitive processing" (number of AEDs: r = -0.433, total DDD: r = -0.415). "Psychomotor speed/alertness" was less related to drug load (number of AEDs: r = -0.285, total DDD: r = -0.232). Statistical control for "psychomotor speed/alertness" hardly changed the correlations of EpiTrack^Ⓡ or "cognitive processing" with drug load indices. AEDs with known adverse profiles negatively affected EpiTrack^Ⓡ and the "cognitive processing" but not the "psychomotor speed/alertness" domain of the computerized test. The results demonstrate that it is less basal psychomotor speed than higher-order cognitive processing which is negatively affected by antiepileptic pharmacotherapy. The results question the value of (computer-)tests with a major emphasis on psychomotor speed and alertness for cognitive drug monitoring.

Efficacy and impact on cognitive functions and quality of life of perampanel as first add-on therapy in patients with epilepsy: A retrospective study

Cognitive dysfunctions are frequent in patients with epilepsy. This comorbidity significantly alters their quality of life and plays an important role in their therapeutic management. Perampanel is a noncompetitive antagonist of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors and is considered a new generation AED (antiepileptic drug) with limited impact on cognitive functions.The aims of this study were to evaluate the efficacy of perampanel as first add-on therapy and its impact on cognitive functions and quality of life in patients with epilepsy followed for 6 months at the Neurology Division of "A. Cardarelli" Hospital in Naples (Italy).

Evaluating the mediating role of executive functions for antiepileptic drugs' effects on IQ in children and adolescents with epilepsy

Several studies suggest that antiepileptic drug (AED) treatment may permanently or reversibly affect intelligence (intelligence quotient [IQ]) in children and adolescents with epilepsy. Since AED treatment preferentially affects attention and executive functions, we evaluated the potentially mediating effect of executive functions in regard to the adverse effects of drug treatment on intelligence. In a retrospective observational study, 178 children and adolescents with refractory and mostly localization-related epilepsies were evaluated in regard to the interrelation of IQ (Wechsler Intelligence Scale for Children [WISC III] short-form), executive functions (EpiTrack-Junior®, a cognitive AED screening test), and drug treatment (drug load). The results indicate that a low IQ was evident in 23%, impaired executive functions in 59% of the patients. Executive functions correlated to IQ (r = 0.60) and the symbol digits and picture arrangement subtests (R² = 0.46) in particular. Odds ratios for impaired executive functions compared to being off drug (33% impaired) increased from 2.0 with one drug (53% impaired) to 9.5 (83% impaired) with at least three drugs. A mediation analysis revealed that drug dependent differences in executive functions mediate the negative effect of the AED load on intelligence. Hence, executive functions appear to link adverse cognitive side effects of AED treatment to intelligence. Considering Catell's two factor model of intelligence, AEDs preferentially affect the aspects of fluid intelligence. The overall impact of AED on intelligence appears mild. It may become relevant, however, when drug-induced impairments persist over longer time intervals during sensitive developmental phases. This issue needs to be addressed in future longitudinal studies.

Cognitive benefits of the ketogenic diet in patients with epilepsy: A systematic overview

The ketogenic diet (KD) has been found to be effective in reducing seizures in patients with treatment-refractory epilepsy. Less attention has been paid to additional cognitive benefits of KD. The aim of the present paper was to provide a comprehensive overview of the studies reporting effects on cognition after KD treatment in adults and children with epilepsy. To address this aim, the clinical literature on cognitive effects of KD in patients with epilepsy was reviewed using a systematic approach. We conclude that using subjective assessments of the patient's experience, cognitive improvements are frequently reported during KD treatment in the domains of alertness, attention, and global cognition. Studies that used objective neuropsychological tests confirmed benefits on alertness but found no improvement in global cognition. There are indications that these improvements are caused by both seizure reduction and direct effects of KD on cognition. The improvements appear to be unrelated to medication reduction, age when KD is started, type of KD, and sleep improvement. The findings in the present overview contribute to a better understanding of the beneficial effects of KD in patients with epilepsy.

The efficacy of a short-term multidisciplinary epilepsy program

RATIONALE

Epilepsy is more than having seizures. Therefore, specialized epilepsy centers in Germany offer multidisciplinary programs for inpatients with pharmacoresistant epilepsies. This monocentric study evaluated the efficacy of a short-term program that is based on a biopsychosocial model of health and conceptualized by occupational therapists, physical therapists, neuropsychologists, and social workers.

METHODS

Of the 1573 patients treated between 2008 and 2014, 1339 were rated using a 7-tiered predefined category system. Outcome domains are compliance, affect, activity, autonomy, communication, fine motor skills, and mobility. Based on a total score, the patients were classified as impaired, functional, or highly functional. Functionality at baseline and changes after the treatment were analyzed and related to demographics, medical, and neuropsychological data.

RESULTS

At baseline, 80.8% of the patients were rated as impaired according to the total score. Impairments were predominantly observed in the domains affect, autonomy, and communication. A better total score at baseline was significantly related to a better neuropsychological functioning and a lower number of concurrent antiepileptic drugs. After the intervention 50.3% of the patients showed significant improvements regarding the total score. Compliance, activity, and affect were the most responsive domains.

CONCLUSION

This study provides promising results with regard to the efficacy of a short-term multidisciplinary epilepsy program. Positive effects could be achieved referring to compliance, activity, and affect. The findings support the relevance of such programs. Subsequent research should focus on the transfer to everyday life.