Neuropsychological effects of epilepsy and antiepileptic drugs

Language impairments in seropositive and seronegative autoimmune encephalitis

BACKGROUND AND OBJECTIVE

Autoimmune encephalitis (AE) is a rare neuroinflammatory disease affecting the central nervous system. To examine language functions in patients with different subsets of AE consisting of seropositive and seronegative groups.

METHODS

Fifty-two patients were recruited from neurology departments in Melbourne, Australia, who met clinical criteria for possible AE. Language tests include the Naming Test from the Sydney Language Battery (SydBat), the semantic fluency trial from the Controlled Oral Word Association Test (COWAT), and the Vocabulary and Similarities subtests of the Weschler Abbreviated Scale of Intelligence-Second Edition. The results were standardised with normative data.

RESULTS

The mean age of our cohort was 52.5 years old, with the average time from hospital admission to recruitment being 38.41 months. At an aggregate level, none of the mean language test z-scores were below normative data. At the patient level, impairment rates were 18.37% for COWAT (animals), 28.57% for SydBat (naming), 4.65% for Similarities, and 4.55% for Vocabulary. Chi-squared goodness of fit tests indicated that observed performances were significantly below expected performances for the SydBat (naming) test (p < 0.0001) and COWAT (animals) (p = 0.004).

DISCUSSION

While, on average, language functions were within normal limits in patients with AE, but a subgroup exhibited lower performance in semantic fluency and visual confrontation naming, with impairment rates below expected norms. To advance understanding of language in chronic AE patients, exploring the impact of seizure burden, antiseizure medication use, and the relationship of language functions with other cognitive functions is crucial.

Long-term low-dose lamotrigine for paroxysmal kinesigenic dyskinesia: a two-year investigation of cognitive function in children

Objective

While low-dose lamotrigine has shown effectiveness in managing paroxysmal kinesigenic dyskinesia (PKD) in pediatric populations, the cognitive consequences of extended use are yet to be fully elucidated. This study seeks to assess the evolution of cognitive functions and the amelioration of attention deficit and hyperactivity disorder (ADHD) symptoms following a two-year lamotrigine treatment in children.

Methods

This investigation employed an open-label, uncontrolled trial design. Between January 2008 and December 2021, thirty-one participants, ranging in age from 6.5 to 14.1 years, were enrolled upon receiving a new diagnosis of PKD, as defined by the clinical diagnostic criteria set by Bruno in 2004. Comprehensive evaluation of PRRT2 variants and 16p11.2 microdeletion was achieved using whole-exome sequencing (WES) and bioinformatics analysis of copy number variant (CNV) for all subjects. Immediately after diagnosis, participants commenced treatment with low-dose lamotrigine. Cognitive function was assessed using the Wechsler Intelligence Scale for Children-Chinese Revised (WISC-CR) at baseline and after 2 years, with ADHD diagnoses and symptom severity simultaneously assessed by experts in accordance with the DSM-IV diagnostic criteria for ADHD and the ADHD Rating Scale-IV (ADHD-RS-IV).

Results

Initially, twelve out of 31 patients (38.7%) presented with comorbid ADHD. The latency to treatment initiation was notably longer in PKD patients with ADHD (30.75 ± 12.88 months) than in those without ADHD (11.66 ± 9.08 months), t = 4.856, p<0.001. Notably, patients with a latency exceeding 2 years exhibited a heightened risk for comorbid ADHD (OR = 4.671, P=0.015) in comparison to those with shorter latency. Out of the cohort, twenty-five patients saw the clinical trial to its completion. These individuals demonstrated a marked elevation in WISC-CR scores at the 2-year mark relative to the outset across FSIQ (baseline mean: 108.72 ± 10.45 vs 24 months: 110.56 ± 10.03, p=0.001), VIQ (baseline mean: 109.44 ± 11.15 vs 24 months: 110.80 ± 10.44, p=0.028), and PIQ domains (baseline mean: 106.52 ± 9.74 vs 24 months: 108.24 ± 9.38, p=0.012). Concurrently, a substantial mitigation was observed in ADHD inattention at 2 years compared to baseline (p<0.001), with an average total subscale scores decrement from 9.04 ± 4.99 to 6.24 ± 4.05.

Conclusion

Prolonged duration of untreated PKD in children may elevate the risk of ADHD comorbidity. Notably, following a 2-year lamotrigine regimen, enhancements were observed in both cognitive test outcomes and ADHD symptomatology.

Measures of Subjective Memory for People with Epilepsy: A Systematic Review of Measurement Properties

People with epilepsy frequently express concern about the burden of memory problems in their everyday lives. Self-report memory questionnaires may provide valuable insight into individuals' perceptions of their everyday memory performance and changes over time. Yet, despite their potential utility, the measurement properties of self-report memory questionnaires have not been evaluated in epilepsy. This systematic review aimed to provide a critical appraisal of the measurement properties of self-report memory questionnaires for adults with epilepsy. Following protocol registration (PROSPERO CRD42020210967), a systematic search of PubMed, EMBASE, Web of Science, CINAHL, and PsychInfo from database inception until 27 May 2021 was conducted. Eligible studies were published in English-language peer-reviewed journals, recruited adults with epilepsy, and reported on the development or evaluation of the measurement properties of a self-report memory questionnaire. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology was used to evaluate each study of a measurement property, and results were qualitatively synthesised. In total, 80 articles and one test manual were located containing 153 studies of measurement properties pertinent to 23 self-report memory questionnaires. Overall, no scale could be recommended outright for the evaluation of subjective memory symptoms in adults with epilepsy. This was due to the near absence of dedicated content validation studies relevant to this population and shortcomings in the methodology and scientific reporting of available studies of structural validity. Recommendations to support the advancement and psychometric validation of self-report memory questionnaires for people with epilepsy are provided.

The Scale Assessment of Executive Functions-Adult (SAEF-A): Construction of a valid ecological instrument

OBJECTIVES

This study aims to validate the SAEF-A (Scale Assessment Of Executive Functions-Adult) test, a new instrument for measuring executive functions in adults.

MATERIALS AND METHODS

The study participants are residents of Fez-Meknes over 18 years old. Two groups were enrolled: people with epilepsy and a healthy group. We constructed the tests in all three Moroccan languages: Darija, Tamazight, and Arabic. We validated the SAEF-A test according to Bernaud's instructions compared to the BRIEF-A test.

RESULTS

The Alpha Cronbach and Split Half were 92% and 88%, respectively. Exploratory research results highlight five facets of perceived value. Significant convergent validation existed between the BRIEF-A subscales and the SAEF-A scale. The results show that the people with epilepsy sample can be discriminated from the healthy ones in all dimensions, except planning, with a minor difference.

CONCLUSIONS

The results provide good reliability and validity for the SAEF-A. It will be helpful in studies of Moroccan adults and other people.

Screening for ADHD in Adult Patients With Epilepsy: Prevalence of Symptoms and Challenges to Diagnosis

OBJECTIVE

Given the complex nature of seizure disorders and their treatments, ADHD may be underdiagnosed in this population. We hypothesized that a higher percentage of patients presenting to a seizure clinic would endorse ADHD symptoms compared to rates reported in the general population and that formal screening for ADHD symptoms would identify patients with previously undiagnosed comorbid ADHD.

METHODS

In this study, we surveyed 312 adults in a seizure clinic using the Adult ADHD Self-Report Scale (ASRS-v1.1).

RESULTS

We found that 90 patients (28.8%) screened positive with the ASRS-v1.1, but only nine of these patients were able to complete neuropsychological testing,. Out of these patients, only one was diagnosed with possible ADHD.

CONCLUSION

Through this process, we identified many challenges to making a new ADHD diagnosis in this population, including attention deficits due to other medical or psychiatric diagnoses, a positive urine drug screen, lack of collateral report/information about developmental history, and barriers to neuropsychological evaluation.

Comparing the synaptic potentiation in schaffer collateral-CA1 synapses in dorsal and intermediate regions of the hippocampus in normal and kindled rats

There is growing evidence that the hippocampus comprises diverse neural circuits that exhibit longitudinal variation in their properties, however, the intermediate region of the hippocampus has received comparatively little attention. Therefore, this study was designed to compared short- and long-term synaptic plasticity between the dorsal and intermediate regions of the hippocampus in normal and PTZ-kindled rats. Short-term plasticity was assessed by measuring the ratio of field excitatory postsynaptic potentials' (fEPSPs) slope in response to paired-pulse stimulation at three different inter-pulse intervals (20, 80, and 160 ms), while long-term plasticity was assessed using primed burst stimulation (PBS). The results showed that the basal synaptic strength differed between the dorsal and intermediate regions of the hippocampus in both control and kindled rats. In the control group, paired-pulse stimulation of Schaffer collaterals resulted in a significantly lower fEPSP slope in the intermediate part of the hippocampus compared to the dorsal region. Additionally, the magnitude of long-term potentiation (LTP) was significantly lower in the intermediate part of the hippocampus compared to the dorsal region. In PTZ-kindled rats, both short-term facilitation and long-term potentiation were impaired in both regions of the hippocampus. Interestingly, there was no significant difference in synaptic plasticity between the dorsal and intermediate regions in PTZ-kindled rats, despite impairments in both regions. This suggests that seizures eliminate the regional difference between the dorsal and intermediate parts of the hippocampus, resulting in similar electrophysiological activity in both regions in kindled animals. Future studies should consider this when investigating the responses of the dorsal and intermediate regions of the hippocampus following PTZ kindling.

Impact of two ketogenic diet types in refractory childhood epilepsy

BACKGROUND

Ketogenic diet (KD) refers to any diet in which food composition induces a ketogenic state of human metabolism.

OBJECTIVE

To assess short- and long-term efficacy, safety, and tolerability of KD [classic KD and modified Atkins diet (MAD)] in childhood drug-resistant epilepsy (DRE) and to investigate the effect of KD on electroencephalographic (EEG) features of children with DRE.

METHODS

Forty patients diagnosed with DRE according to International League Against Epilepsy were included and randomly assigned into classic KD or MAD groups. KD was initiated after clinical, lipid profile and EEG documentation, and regular follow-up was done for 24 months.

RESULTS

Out of 40 patients with DRE, 30 completed this study. Both classic KD and MAD were effective in seizure control as 60% in classic KD group and 53.33% in MAD group became seizure free, and the remaining showed ≥50% seizure reduction. Lipid profile remained within acceptable levels throughout the study period in both groups. Adverse effects were mild and managed medically with an improvement of growth parameters and EEG during the study period.

CONCLUSIONS

KD is an effective and safe non-pharmacologic, non-surgical therapy for the management of DRE with a positive impact on growth and EEG.

IMPACT

Both common types of KD (classic KD and MAD) are effective for DRE, but unfortunately, nonadherence and dropout rates are frequent. High serum lipid profile (cardiovascular AE) is often suspected in children following a high-fat diet, but lipid profile remained in the acceptable level up to 24 months. Therefore, KD constitutes a safe treatment. KD had a positive impact on growth, despite inconsistent results of the KD's effect on growth. In addition to showing strong clinical effectiveness, KD also considerably decreased the frequency of interictal epileptiform discharges and enhanced the EEG background rhythm.

Patient family engagement and partnership: Pilot survey results in assessing behavior, communication, and quality of life in children with Lennox-Gastaut syndrome and other drug-resistant epilepsy

OBJECTIVES

Lennox-Gastaut Syndrome (LGS) and other drug-resistant epilepsy (DRE) can impact behavior, communication, and quality of life (QoL). In collaboration with community engagement efforts with the Lennox-Gastaut Syndrome Foundation (LGSF), we aimed to gain an initial snapshot of patient and family perspectives and experiences with evaluation of behavior, communication, and QoL.

METHODS

A cross-sectional survey was conducted to collect self-reported information from caregivers of children with LGS and other DRE regarding their perspectives and experiences with healthcare providers' evaluation of behavior, communication, and QoL. The survey tool was developed by the study investigators in partnership with the LGS Foundation and had diffused to caregivers online by epilepsy advocacy groups including the Pediatric Epilepsy Surgery Alliance (PESA). Responses were analyzed. Descriptive statistics were calculated. The survey asked for caregiver perspectives and assessed which instruments the caregivers had previously been given for measuring these domains.

RESULTS

Responses from 245 caregivers were included, with 132 (54%) caregivers of an individual with LGS and 113 (46%) caregivers of an individual with non-LGS related DRE. Respondents reported that 66% of their loved ones had undergone epilepsy-related surgery. Over 90% agreed that measuring behavior, communication, and QoL was important, but fewer than half felt that their healthcare providers evaluated these domains well. LGS caregivers largely shared non-LGS caregivers' perspectives; however, they reported more frequently that communication was not evaluated enough. Barriers to measuring these domains included a lack of good surveys (developmentally appropriate and specific to the type of epilepsy) or not receiving any survey instruments for these domains during clinic appointments. Caregivers play a crucial role for individuals with DRE, and their input is essential in identifying challenges and needs. Caregivers believe that measuring behavior, communication, and quality of life is important, and most of them feel that their loved ones are not adequately evaluated during their healthcare encounters. There is a need for appropriately scaled survey instruments to measure areas of importance for patients and caregivers, as well as incorporation of these outcomes in the healthcare discussion.

Black-Box Warnings of Antiseizure Medications: What is Inside the Box?

Antiseizure medications can cause serious adverse reactions and have deleterious drug interactions that often complicate the clinical management of patients. When the US Food and Drug Administration (FDA) wants to alert healthcare providers and patients about the risk of potentially serious or fatal drug reactions, the FDA requires the manufacturers of these medications to format these warnings within a "black-box" border, and prominently display this box on the first section of the package insert; such warnings are called "black-box warnings (BBWs)". The BBW is a way for the FDA to urge physicians to evaluate patients more rigorously and carefully weigh the risks and benefits, before prescribing medication that has the potential to cause serious adverse reactions, and to formulate a plan for close monitoring during therapy. The FDA BBW provides the extra layer of safety but many healthcare providers fail to comply with these warnings. Currently, there are 26 FDA-approved antiseizure medications in the US market, 38% of which have received BBWs, and most of the antiseizure medications with BBWs are older-generation drugs. Some antiseizure medications have multiple BBWs; for example, valproic acid has three BBWs including hepatotoxicity, fetal risk, and pancreatitis, carbamazepine has BBWs of serious skin and hematological reactions, and felbamate also has two BBWs including hepatic failure and aplastic anemia. The purpose of this review is to provide insight into each BBW received by antiseizure medications and discuss the FDA recommendations for evaluating the drug benefit/risk, and for monitoring parameters before the initiation of and during treatment.

Reliable change on the selective reminding test in a series of left-hemisphere language dominant patients with right temporal lobe epilepsy

The Selective Reminding Test (SRT) is widely used in pre-surgical evaluations for people with epilepsy; however, important characteristics such as reliability and stability over time within an epilepsy-specific control cohort are unclear. In this study, we document test-retest reliabilities, practice effects, and Reliable Change Indices (RCI) for this test in a sample of right temporal lobe epilepsy patients who are left hemisphere dominant for language and underwent surgical resection on the right temporal lobe. A sample of 101 adults with a right temporal lobe seizure focus (mean age = 38.5) was administered the SRT pre- and post-right temporal lobe surgery. Test-retest reliabilities were modest (r = 0.44-0.59). Practice effects were minimal (0.25-2.04). Reliable Change Indices were calculated and ranged from 4 to 26 depending on the SRT index. The RCI's indicate that relatively moderate to large changes on the SRT are needed for a change score to be considered a significant change in an individual's performance. The RCIs can be used to detect a reliable change in patients undergoing left temporal lobe epilepsy surgery who are at significant risk for verbal memory decline.

Attenuation of Seizures, Cognitive Deficits, and Brain Histopathology by Phytochemicals of Imperata cylindrica (L.) P. Beauv (Poaceae) in Acute and Chronic Mutant Drosophila melanogaster Epilepsy Models

Imperata cylindrica is a globally distributed plant known for its antiepileptic attributes, but there is a scarcity of robust evidence for its efficacy. The study investigated neuroprotective attributes of Imperata cylindrica root extract on neuropathological features of epilepsy in a Drosophila melanogaster mutant model of epilepsy. It was conducted on 10-day-old (at the initiation of study) male post-eclosion bang-senseless paralytic Drosophila (parabss1) involved acute (1-3 h) and chronic (6-18 days) experiments; n = 50 flies per group (convulsions tests); n = 100 flies per group (learning/memory tests and histological examination). Administrations were done in 1 g standard fly food, per os. The mutant flies of study (parabss1) showed marked age-dependent progressive brain neurodegeneration and axonal degeneration, significant (P < 0.05) bang sensitivity and convulsions, and cognitive deficits due to up-regulation of the paralytic gene in our mutants. The neuropathological findings were significantly (P < 0.05) alleviated in dose and duration-dependent fashions to near normal/normal after acute and chronic treatment with extract similar to sodium valproate. Therefore, para is expressed in neurons of brain tissues in our mutant flies to bring about epilepsy phenotypes and behaviors of the current juvenile and old-adult mutant D. melanogaster models of epilepsy. The herb exerts neuroprotection by anticonvulsant and antiepileptogenic mechanisms in mutant D. melanogaster due to plant flavonoids, polyphenols, and chromones (1 and 2) which exert antioxidative and receptor or voltage-gated sodium ion channels' inhibitory properties, and thus causing reduced inflammation and apoptosis, increased tissue repair, and improved cell biology in the brain of mutant flies. The methanol root extract provides anticonvulsant and antiepileptogenic medicinal values which protect epileptic D. melanogaster. Therefore, the herb should be advanced for more experimental and clinical studies to confirm its efficacy in treating epilepsy.

Verbosity with retelling: Narrative discourse production in temporal lobe epilepsy

To examine micro- and macrolinguistic underpinnings of circumstantiality in temporal lobe epilepsy (TLE), we examined the elicited narrative output of 15 individuals with TLE and 14 controls. To replicate and extend Field and colleagues' (2000) work, participants were asked to produce five immediately consecutive elicitations of an eight-frame cartoon "Cowboy Story" (Joanette et al., 1986). Following transcription and coding, detailed multi-level discourse analysis demonstrated a typical pattern of compression in controls. The narratives produced by individuals with TLE were less fluent, cohesive, and coherent across trials: producing fewer novel units and more repetitive and extraneous content. Significant group by trial interactions in sample length, spontaneous duration, and statements, were not explained by seizure burden, age, or lexical retrieval deficits. These findings suggest that they do not benefit from repeated engagement with a narrative in the same manner as controls. Disturbed social cognition and pragmatics in TLE might underpin communication inefficiencies.

Acute to Chronic Electro-Clinical Manifestations of Neuro-COVID and the Long-Haul Consequences in People With Epilepsy: A Review

Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection can involve the central nervous system (CNS). Acute symptomatic seizures or epileptiform discharges have not been commonly reported in patients with altered mental status related to coronavirus disease 2019 (COVID-19) infection. However, long-term neurological symptoms have been reported after COVID-19 infection (i.e., brain fog, cognitive complaints, and confusion), suggesting chronic encephalopathy. People with epilepsy (PWE) have been specifically affected by the COVID-19 pandemic, with changes in their seizure frequency, quality of life, health care accessibility, and medication interactions. This narrative review highlights possible pathophysiological mechanisms of COVID-19 on the brain, related to short- and long-term epileptiform activity and the impact of this infection on PWE.

Developmental organization of neural dynamics supporting auditory perception

Purpose:

A prominent view of language acquisition involves learning to ignore irrelevant auditory signals through functional reorganization, enabling more efficient processing of relevant information. Yet, few studies have characterized the neural spatiotemporal dynamics supporting rapid detection and subsequent disregard of irrelevant auditory information, in the developing brain. To address this unknown, the present study modeled the developmental acquisition of cost-efficient neural dynamics for auditory processing, using intracranial electrocorticographic responses measured in individuals receiving standard-of-care treatment for drug-resistant, focal epilepsy. We also provided evidence demonstrating the maturation of an anterior-to-posterior functional division within the superior-temporal gyrus (STG), which is known to exist in the adult STG.

Methods:

We studied 32 patients undergoing extraoperative electrocorticography (age range: eight months to 28 years) and analyzed 2,039 intracranial electrode sites outside the seizure onset zone, interictal spike-generating areas, and MRI lesions. Patients were given forward (normal) speech sounds, backward-played speech sounds, and signal-correlated noises during a task-free condition. We then quantified sound processing-related neural costs at given time windows using high-gamma amplitude at 70–110 Hz and animated the group-level high-gamma dynamics on a spatially normalized three-dimensional brain surface. Finally, we determined if age independently contributed to high-gamma dynamics across brain regions and time windows.

Results:

Group-level analysis of noise-related neural costs in the STG revealed developmental enhancement of early high-gamma augmentation and diminution of delayed augmentation. Analysis of speech-related high-gamma activity demonstrated an anterior-to-posterior functional parcellation in the STG. The left anterior STG showed sustained augmentation throughout stimulus presentation, whereas the left posterior STG showed transient augmentation after stimulus onset. We found a double dissociation between the locations and developmental changes in speech sound-related high-gamma dynamics. Early left anterior STG high-gamma augmentation (i.e., within 200 ms post-stimulus onset) showed developmental enhancement, whereas delayed left posterior STG high-gamma augmentation declined with development.

Conclusions:

Our observations support the model that, with age, the human STG refines neural dynamics to rapidly detect and subsequently disregard uninformative acoustic noises. Our study also supports the notion that the anterior-to-posterior functional division within the left STG is gradually strengthened for efficient speech sound perception after birth.

Naming-related spectral responses predict neuropsychological outcome after epilepsy surgery

This prospective study determined the use of intracranially recorded spectral responses during naming tasks in predicting neuropsychological performance following epilepsy surgery. We recruited 65 patients with drug-resistant focal epilepsy who underwent preoperative neuropsychological assessment and intracranial EEG recording. The Clinical Evaluation of Language Fundamentals evaluated the baseline and postoperative language function. During extra-operative intracranial EEG recording, we assigned patients to undergo auditory and picture naming tasks. Time-frequency analysis determined the spatiotemporal characteristics of naming-related amplitude modulations, including high gamma augmentation at 70-110 Hz. We surgically removed the presumed epileptogenic zone based on the intracranial EEG and MRI abnormalities while maximally preserving the eloquent areas defined by electrical stimulation mapping. The multivariate regression model incorporating auditory naming-related high gamma augmentation predicted the postoperative changes in Core Language Score with r2 of 0.37 and in Expressive Language Index with r2 of 0.32. Independently of the effects of epilepsy and neuroimaging profiles, higher high gamma augmentation at the resected language-dominant hemispheric area predicted a more severe postoperative decline in Core Language Score and Expressive Language Index. Conversely, the model incorporating picture naming-related high gamma augmentation predicted the change in Receptive Language Index with an r2 of 0.50. Higher high gamma augmentation independently predicted a more severe postoperative decline in Receptive Language Index. Ancillary regression analysis indicated that naming-related low gamma augmentation and alpha/beta attenuation likewise independently predicted a more severe Core Language Score decline. The machine learning-based prediction model suggested that naming-related high gamma augmentation, among all spectral responses used as predictors, most strongly contributed to the improved prediction of patients showing a >5-point Core Language Score decline (reflecting the lower 25th percentile among patients). We generated the model-based atlas visualizing sites, which, if resected, would lead to such a language decline. With a 5-fold cross-validation procedure, the auditory naming-based model predicted patients who had such a postoperative language decline with an accuracy of 0.80. The model indicated that virtual resection of an electrical stimulation mapping-defined language site would have increased the relative risk of the Core Language Score decline by 5.28 (95% confidence interval: 3.47-8.02). Especially, that of an electrical stimulation mapping-defined receptive language site would have maximized it to 15.90 (95% confidence interval: 9.59-26.33). In summary, naming-related spectral responses predict neuropsychological outcomes after epilepsy surgery. We have provided our prediction model as an open-source material, which will indicate the postoperative language function of future patients and facilitate external validation at tertiary epilepsy centres.

Effect of Early Surgical Intervention for Brain Tumors Associated with Epilepsy on the Improvement in Memory Performance

We evaluated the effect of early surgical intervention on the change in memory performance of patients with low-grade brain tumors associated with epilepsy. Twenty-three adult patients with low-grade brain tumors and epilepsy who underwent surgery at our institution between 2010 and 2019 were included. The Wechsler Memory Scale-Revised (WMS-R) was used to assess cognitive memory performance. Memory performance before and after surgery was retrospectively evaluated. In addition, the relationships among preoperative memory function, postoperative seizure outcome, preoperative seizure control, temporal lobe lesion, and change in memory function were examined. There were statistically significant improvements from median preoperative to postoperative WMS-R subscale scores for verbal memory, general memory, and delayed recall (p<0.001, p<0.001, and p=0.0055, respectively) regardless of preoperative sores and tumor location. Good postsurgical seizure control was associated with significant improvements in postoperative WMS-R performance. Our results indicated that early surgical intervention might improve postoperative memory function in patients with low-grade brain tumors and epilepsy.

Six-dimensional dynamic tractography atlas of language connectivity in the developing brain

During a verbal conversation, our brain moves through a series of complex linguistic processing stages: sound decoding, semantic comprehension, retrieval of semantically coherent words, and overt production of speech outputs. Each process is thought to be supported by a network consisting of local and long-range connections bridging between major cortical areas. Both temporal and extratemporal lobe regions have functional compartments responsible for distinct language domains, including the perception and production of phonological and semantic components. This study provides quantitative evidence of how directly connected inter-lobar neocortical networks support distinct stages of linguistic processing across brain development. Novel six-dimensional tractography was used to intuitively visualize the strength and temporal dynamics of direct inter-lobar effective connectivity between cortical areas activated during each linguistic processing stage. We analysed 3401 non-epileptic intracranial electrode sites from 37 children with focal epilepsy (aged 5-20 years) who underwent extra-operative electrocorticography recording. Principal component analysis of auditory naming-related high-gamma modulations determined the relative involvement of each cortical area during each linguistic processing stage. To quantify direct effective connectivity, we delivered single-pulse electrical stimulation to 488 temporal and 1581 extratemporal lobe sites and measured the early cortico-cortical spectral responses at distant electrodes. Mixed model analyses determined the effects of naming-related high-gamma co-augmentation between connecting regions, age, and cerebral hemisphere on the strength of effective connectivity independent of epilepsy-related factors. Direct effective connectivity was strongest between extratemporal and temporal lobe site pairs, which were simultaneously activated between sentence offset and verbal response onset (i.e. response preparation period); this connectivity was approximately twice more robust than that with temporal lobe sites activated during stimulus listening or overt response. Conversely, extratemporal lobe sites activated during overt response were equally connected with temporal lobe language sites. Older age was associated with increased strength of inter-lobar effective connectivity especially between those activated during response preparation. The arcuate fasciculus supported approximately two-thirds of the direct effective connectivity pathways from temporal to extratemporal auditory language-related areas but only up to half of those in the opposite direction. The uncinate fasciculus consisted of <2% of those in the temporal-to-extratemporal direction and up to 6% of those in the opposite direction. We, for the first time, provided an atlas which quantifies and animates the strength, dynamics, and direction specificity of inter-lobar neural communications between language areas via the white matter pathways. Language-related effective connectivity may be strengthened in an age-dependent manner even after the age of 5.

Non-mental diseases associated with ADHD across the lifespan: Fidgety Philipp and Pippi Longstocking at risk of multimorbidity?

Several non-mental diseases seem to be associated with an increased risk of ADHD and ADHD seems to be associated with increased risk for non-mental diseases. The underlying trajectories leading to such brain-body co-occurrences are often unclear - are there direct causal relationships from one disorder to the other, or does the sharing of genetic and/or environmental risk factors lead to their occurring together more frequently or both? Our goal with this narrative review was to provide a conceptual synthesis of the associations between ADHD and non-mental disease across the lifespan. We discuss potential shared pathologic mechanisms, genetic background and treatments in co-occurring diseases. For those co-occurrences for which published studies with sufficient sample sizes exist, meta-analyses have been published by others and we discuss those in detail. We conclude that non-mental diseases are common in ADHD and vice versa and add to the disease burden of the patient across the lifespan. Insufficient attention to such co-occurring conditions may result in missed diagnoses and suboptimal treatment in the affected individuals.

Relationship Between Epilepsy and Dreaming: Current Knowledge, Hypotheses, and Perspectives

The interactions between epilepsy and sleep are numerous and the impact of epilepsy on cognition is well documented. Epilepsy is therefore likely to influence dreaming as one sleep-related cognitive activity. The frequency of dream recall is indeed decreased in patients with epilepsy, especially in those with primary generalized seizures. The content of dreams is also disturbed in epilepsy patients, being more negative and with more familiar settings. While several confounding factors (anti-seizure medications, depression and anxiety disorders, cognitive impairment) may partly account for these changes, some observations suggest an effect of seizures themselves on dreams. Indeed, the incorporation of seizure symptoms in dream content has been described, concomitant or not with a focal epileptic discharge during sleep, suggesting that epilepsy might directly or indirectly interfere with dreaming. These observations, together with current knowledge on dream neurophysiology and the links between epilepsy and sleep, suggest that epilepsy may impact not only wake- but also sleep-related cognition.

Cognitive assessment using the Rapid Assessment for Developmental Disabilities, Second Edition (RADD-2)

BACKGROUND

Individuals with developmental disabilities (DD) often have severe impairments and maladaptive behaviours that make it difficult to reliably assess their cognitive abilities. Given these challenges, the Rapid Assessment of Developmental Disabilities, Second Edition (RADD-2), was designed to measure general cognitive ability in this population. The purpose of this study is to demonstrate the battery's psychometric properties when used with individuals with DD who have challenging behavioural and psychiatric conditions and for those who have limited verbal skills.

METHOD

The cognitive and adaptive behaviour skills of 193 children and adults with DD and considerable medical, behavioural and/or psychiatric problems were evaluated using the first and second editions of the RADD, Kaufmann Brief Intelligence Test - 2nd Edition, and Scales of Independent Behaviour - Revised Edition. Medication side effects and challenging behaviours were assessed using the Aberrant Behaviour Checklist.

RESULTS

There were no floor or ceiling effects on the RADD-2. Both the nonverbal index and total scores had strong concurrent validity with other abbreviated tests of intellectual ability and good discriminant validity from measures of adaptive behaviour and medication side effects. RADD-2 scores also had strong criterion validity as they successfully differentiated between all levels of intellectual functioning. Age and sex did not differentially affect RADD-2 performance, and the co-occurrence of psychiatric conditions did not negatively affect performance. The only medical condition associated with lower RADD-2 performance was epilepsy.

CONCLUSIONS

The RADD-2 can quantify the differential cognitive abilities of individuals with DD, even for those with minimal communication skills, challenging behaviours or severe medication side effects that can typically complicate assessment. This brief cognitive battery can be used to measure changes due to interventions, on the one hand, and progression of neurological disease, on the other.

Spontaneous modulations of high-frequency cortical activity

OBJECTIVE

We clarified the clinical and mechanistic significance of physiological modulations of high-frequency broadband cortical activity associated with spontaneous saccadic eye movements during a resting state.

METHODS

We studied 30 patients who underwent epilepsy surgery following extraoperative electrocorticography and electrooculography recordings. We determined whether high-gamma activity at 70-110 Hz preceding saccade onset would predict upcoming ocular behaviors. We assessed how accurately the model incorporating saccade-related high-gamma modulations would localize the primary visual cortex defined by electrical stimulation.

RESULTS

The dynamic atlas demonstrated transient high-gamma suppression in the striatal cortex before saccade onset and high-gamma augmentation subsequently involving the widespread posterior brain regions. More intense striatal high-gamma suppression predicted the upcoming saccade directed to the ipsilateral side and lasting longer in duration. The bagged-tree-ensemble model demonstrated that intense saccade-related high-gamma modulations localized the visual cortex with an accuracy of 95%.

CONCLUSIONS

We successfully animated the neural dynamics supporting saccadic suppression, a principal mechanism minimizing the perception of blurred vision during rapid eye movements. The primary visual cortex per se may prepare actively in advance for massive image motion expected during upcoming prolonged saccades.

SIGNIFICANCE

Measuring saccade-related electrocorticographic signals may help localize the visual cortex and avoid misperceiving physiological high-frequency activity as epileptogenic.

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.

Temporal lobe dysfunction in late-onset epilepsy of unknown origin

OBJECTIVE

Epilepsy with onset in the adulthood is an increasing health problem, due to the progressive aging of the worldwide population. Whether the causes remain undetermined, the disease is defined as Late-Onset Epilepsy of Unknown origin (LOEU). The aim of this study was to evaluate the semiological, electroencephalographic, metabolic, and neuropsychological features of LOEU.

METHODS

We selected patients with late-onset epilepsy (LOE) (≥55 years), whose causes of the disease have been excluded with a deep clinical-instrumental characterization, including brain MRI, EEG, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography (FDG-PET), and neuropsychological assessment.

RESULTS

Twenty-three LOEU cases were retrospectively recruited. Half presented focal-onset seizures (FOS), the others focal to bilateral tonic-clonic seizures (FBTCS). All demonstrated a mild phenotype, with no recurrence of seizures on single antiseizure treatment at prolonged follow-up. Brain MRI scans were normal in 12 patients (52.3%) and showed nonspecific gliosis or mild atrophy in ten (43.5%); hippocampal sclerosis (HS) was observed in one. In 17/23 (73.9%), the EEG showed slow and/or epileptiform activity of the temporal areas. Brain FDG-PET revealed temporal lobe hypometabolism, mostly ipsilateral to EEG abnormal activity, or multifocal temporal and extra-temporal (cortical, subcortical and subtentorial) clusters of hypometabolism. The neuropsychological analysis demonstrated three different profiles: normal (43.5%), with focal deficits (39.1%) or mild multidomain impairment (17.4%).

SIGNIFICANCE

Late-Onset Epilepsy of Unknown origin can present as FOS or FBTCS, both with good prognosis. The application of metabolic imaging and neurophysiology techniques in these patients points to the dysfunction of the temporal structures, whose role in the pathogenetic process of the disease remains to be clarified.

Objective interictal electrophysiology biomarkers optimize prediction of epilepsy surgery outcome

Researchers have looked for rapidly- and objectively-measurable electrophysiology biomarkers that accurately localize the epileptogenic zone. Promising candidates include interictal high-frequency oscillation and phase-amplitude coupling. Investigators have independently created the toolboxes that compute the high-frequency oscillation rate and the severity of phase-amplitude coupling. This study of 135 patients determined what toolboxes and analytic approaches would optimally classify patients achieving post-operative seizure control. Four different detector toolboxes computed the rate of high-frequency oscillation at ≥80 Hz at intracranial EEG channels. Another toolbox calculated the modulation index reflecting the strength of phase-amplitude coupling between high-frequency oscillation and slow-wave at 3–4 Hz. We defined the completeness of resection of interictally-abnormal regions as the subtraction of high-frequency oscillation rate (or modulation index) averaged across all preserved sites from that averaged across all resected sites. We computed the outcome classification accuracy of the logistic regression-based standard model considering clinical, ictal intracranial EEG and neuroimaging variables alone. We then determined how well the incorporation of high-frequency oscillation/modulation index would improve the standard model mentioned above. To assess the anatomical variability across non-epileptic sites, we generated the normative atlas of detector-specific high-frequency oscillation and modulation index. Each atlas allowed us to compute the statistical deviation of high-frequency oscillation/modulation index from the non-epileptic mean. We determined whether the model accuracy would be improved by incorporating absolute or normalized high-frequency oscillation/modulation index as a biomarker assessing interictally-abnormal regions. We finally determined whether the model accuracy would be improved by selectively incorporating high-frequency oscillation verified to have high-frequency oscillatory components unattributable to a high-pass filtering effect. Ninety-five patients achieved successful seizure control, defined as International League against Epilepsy class 1 outcome. Multivariate logistic regression analysis demonstrated that complete resection of interictally-abnormal regions additively increased the chance of success. The model accuracy was further improved by incorporating z-score normalized high-frequency oscillation/modulation index or selective incorporation of verified high-frequency oscillation. The standard model had a classification accuracy of 0.75. Incorporation of normalized high-frequency oscillation/modulation index or verified high-frequency oscillation improved the classification accuracy up to 0.82. These outcome prediction models survived the cross-validation process and demonstrated an agreement between the model-based likelihood of success and the observed success on an individual basis. Interictal high-frequency oscillation and modulation index had a comparably additive utility in epilepsy presurgical evaluation. Our empirical data support the theoretical notion that the prediction of post-operative seizure outcomes can be optimized with the consideration of both interictal and ictal abnormalities.

Visual Motor and Executive Functioning in Adult Patients with Primary Generalized Epilepsy: A Pilot Study

Background and Purpose

Epilepsy is a neuropsychological disorder which can lead to various cognitive deficits of varying levels. Primary generalized epilepsy is characterized by bilateral ictal electroencephalography patterns and excessive neural activity found in both hemispheres of the brain. There is dearth of research on primary generalized epilepsy in adult population. The present study investigates the visual motor and executive functioning deficits in patients with primary generalized epilepsy.

Methods

Study was conducted on 30 participants (n=30) divided into target and normal control group. Target group consisted of patients diagnosed with primary generalized epilepsy with minimum 5 years of illness. Bender-Gestalt test (BGT) and Wisconsin's Card Sorting Test (WCST) was administered on both the groups.

Results

A significant difference was found between target group and control group's performances on BGT which indicates that visual motor functioning of control group was better than target group. A significant difference in executive functioning was found in performance of epilepsy patients and non-patients on the domains of WCST.

Conclusions

Both executive and visuomotor functioning are significantly affected in patients of primary generalized epilepsy in adult patients.

Your verbal questions beginning with 'what' will rapidly deactivate the left prefrontal cortex of listeners

The left prefrontal cortex is essential for verbal communication. It remains uncertain at what timing, to what extent, and what type of phrase initiates left-hemispheric dominant prefrontal activation during comprehension of spoken sentences. We clarified this issue by measuring event-related high-gamma activity during a task to respond to three-phrase questions configured in different orders. Questions beginning with a wh-interrogative deactivated the left posterior prefrontal cortex right after the 1st phrase offset and the anterior prefrontal cortex after the 2nd phrase offset. Left prefrontal high-gamma activity augmented subsequently and maximized around the 3rd phrase offset. Conversely, questions starting with a concrete phrase deactivated the right orbitofrontal region and then activated the left posterior prefrontal cortex after the 1st phrase offset. Regardless of sentence types, high-gamma activity emerged earlier, by one phrase, in the left posterior prefrontal than anterior prefrontal region. Sentences beginning with a wh-interrogative may initially deactivate the left prefrontal cortex to prioritize the bottom-up processing of upcoming auditory information. A concrete phrase may obliterate the inhibitory function of the right orbitofrontal region and facilitate top-down lexical prediction by the left prefrontal cortex. The left anterior prefrontal regions may be recruited for semantic integration of multiple concrete phrases.

Cognition in adult patients with newly diagnosed non-lesional temporal lobe epilepsy

OBJECTIVE

To evaluate whether cognitive performance is affected in newly diagnosed temporal lobe epilepsy (TLE) and to determine the most vulnerable cognitive domains.

METHODS

In this baseline longitudinal study, differences in memory and non-memory cognitive functions were assessed using comprehensive neuropsychological test batteries in 21 adult patients with newly diagnosed non-lesional TLE and individually matched controls. In addition, the analyses included ratings of self-perceived emotional status.

RESULTS

The patients performed more poorly than the control group regarding delayed visual memory (p = 0.013) and executive function tasks related to switching (Trail Making Test and verbal fluency shifting; p = 0.025 and p = 0.03, respectively). We found no differences in verbal learning and memory, attention/working memory/processing speed, and other executive functions.

SIGNIFICANCE

Our results show that patients with TLE often have specific cognitive deficits at time of diagnosis, even in the absence of structural brain abnormalities. This supports the hypothesis that memory dysfunction is linked to an underlying pathology rather than to the effect of recurrent seizures, long-term use of anti-seizure medication, or other epilepsy-related factors. As certain executive functions are affected at an early stage, the pathology may involve brain regions beyond the temporal lobe and may comprise larger brain networks. These results indicate the need for greater awareness of cognition at the time of diagnosis of TLE and before initiation of treatment, and integration of neuropsychological assessment into early routine clinical care.

Determinants of caregiver burden in male patients with epilepsy following penetrating traumatic brain injury

PURPOSE

We determined burden of caring for patients with post-traumatic epilepsy (PTE) following penetrating traumatic brain injury (TBI) and identified factors predicting higher burden.

METHOD

We assessed 331 caregiver-veteran dyads in Phase 2 (136 PTE, 136 non-PTE, and 59 HC dyads), 133 in Phase 4 (47 PTE, 56 non-PTE, and 30 HC dyads) - 30 years later, and 46 dyads in the follow-up study (18 PTE, 19 non-PTE, and 9 HC). Caregiver's burden was measured by Zarit Burden Index and a questionnaire. Veterans completed demographic, mental and physical well-being, quality-of-life, and medical-related information. Caregivers provided information about burden and their assessments of cognitive decline and neuropsychiatric status of the veterans.

RESULTS

PTE caregivers perceived significantly more burden than comparison groups at all phases. Bivariate analyses revealed that caregiver distress due to the veteran's neuropsychiatric state including cognitive decline, apathy, and disinhibition and the veteran's characteristics including older age at epilepsy onset and role limitation due to physical problems were associated with higher burden. Finally, we revealed disinhibition distress, and role imitation due to physical problems as the predictors in a model of caregiver burden.

CONCLUSION

Elevated PTE caregiver burden is persistent across the life span suggesting that caregivers could benefit from counseling and targeted psychosocial interventions to reduce their burden.

Pentylenetetrazol and Morphine Interaction in a State-dependent Memory Model: Role of CREB Signaling

Introduction:

State-dependent (STD) memory is a process, in which the learned information can be optimally retrieved only when the subject is in the state similar to the encoding phase. This phenomenon has been widely studied with morphine. Several studies have reported that Pentylenetetrazole (PTZ) impairs memory in experimental animal models. Due to certain mechanistic interactions between morphine and PTZ, it is hypothesized that PTZ may interfere with the morphine-STD. The cyclic adenosine monophosphate Response Element-Binding (CREB) is considered as the main downstream marker for long-term memory. This study was designed to determine the possible interaction between PTZ and morphine STD and the presumable changes in CREB mRNA.

Methods:

In an Inhibitory Avoidance (IA) model, posttraining morphine (2.5, 5, and 7.5 mg/ kg-i.p.) was used. The pre-test morphine was evaluated for morphine-induced STD memory. Moreover, the effect of a pre-test PTZ (60 mg/kg-i.p.) was studied along with morphine STD. Locomotion testing was carried out using open-field. Eventually, using real-time-PCR, the CREB mRNA changes in the hippocampus were evaluated.

Results:

Posttraining MOR (7.5 mg/kg-i.p.) impaired IA memory (P<0.001). The pre-test injection of similar doses of morphine recovered the morphine-induced memory impairment (P<0.001). The pre-test PTZ impaired the IA memory recall (P<0.001); however, the pre-test PTZ along with morphine STD potentiated the morphine-induced STD (P<0.001). Alterations in CREB mRNA were observed in all groups. No difference was seen in the locomotor activity.

Conclusion:

Presumably, the certain interactive effect of PTZ on morphine-induced STD is mediated through gamma-aminobutyric acid and opioid systems via CREB signaling.

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.

The association between ADHD and physical health: a co-twin control study

Attention-deficit/hyperactivity disorder (ADHD) has been associated with increased risk for physical comorbidity. This study used a twin cohort to investigate the association between physical diseases and phenotypic variations of ADHD. A twin cohort enriched for ADHD and other neurodevelopmental conditions were analysed. The Attention Problems subscale of the Child Behavior Checklist/Adult Behavior Checklist (CBCL/ABCL-AP) was used to measure the participants’ severity of ADHD symptoms. Physical health issues were obtained with a validated questionnaire and were tested in relation to ADHD symptom severity in a co-twin control model. Neurological problems were significantly associated with a diagnosis of ADHD. A conditional model for the analysis of within-twin pair effects revealed an inverse association between digestive problems and the severity of ADHD symptoms, after adjusting for co-existing autism spectrum disorder and ADHD medications. Our findings suggest that individuals with ADHD are susceptible to neurological problems, why a thorough neurological check-up is indicated in clinical practice for this population. In addition, health conditions of digestive system could be considered as a non-shared environmental factor for behavioral phenotypes in ADHD. It supports the possible role of gut-brain axis in the underpinnings of ADHD symptoms, at least for a subgroup of individuals with certain genetic predisposition.

A prospective pilot study of cognitive impairment and mood in adults with first seizure, new-onset epilepsy, and newly diagnosed epilepsy at time of initial seizure presentation

INTRODUCTION

This is an observational prospective cohort study of cognition and mood in individuals presenting to a tertiary neurology clinic with first unprovoked seizure (FS), new-onset epilepsy (NOE), and newly diagnosed epilepsy (NDE). Our aim was to understand the cognitive profile of these three diagnostic groups at the time of first presentation. Follow-up was obtained to evaluate any association between cognition at presentation and subsequent clinical course.

METHODS

Forty-three participants (age: 18-60 years) were recruited with FS (n = 17), NOE (n = 16), and NDE (n = 10). Clinical details, neuropsychological testing, and screening for mood disorders were obtained at the time of presentation to clinic. Seizure recurrence was evaluated at clinic follow-up at least 6-12 months following the initial presentation.

RESULTS

In all groups, general intelligence (intelligence quotient [IQ]) was consistent with population norms, but more than half of participants (55.8%) were impaired in at least one cognitive domain. The most commonly impaired domain in all diagnostic groups was visuospatial and visuoconstruction suggesting that it may be a sensitive marker of early cognitive impairment. Those with epilepsy (NOE and NDE) at initial presentation were more likely to be impaired than those with FS, particularly on tests of attention, working memory, and processing speed. Seven participants with FS converted to NOE (FSNOE) at follow-up. They were more likely to be impaired on tests of memory than those with FS who did not convert to NOE. On mood screening, 21% of participants scored moderate or severe for depressive symptoms, and 25.6% of participants scored moderate or severe for anxiety symptoms.

DISCUSSION

Cognitive impairment and mood changes are common at first seizure presentation and mirror the pattern seen in chronic epilepsy. This cooccurrence of symptomatology at disease onset prior to prolonged antiepilepsy drug exposure suggests a shared underlying disease mechanism and carries important clinical implications for effective diagnosis and management of epilepsy. Furthermore, early cognitive testing may become a clinical biomarker and enable the prediction of an individual's clinical course.

In the eye of the beholder: Using a multiple-informant approach to examine the mediating effect of cognitive functioning on emotional and behavioral problems in children with an active epilepsy

PURPOSE

Childhood epilepsy is often associated with cognitive impairments and psychosocial problems. However, it is not clear which factors mediate symptom severity and child's resilience. Emotional and behavioral problems have been associated with various home and school environments, suggesting that information collected may vary depending on both context and informant. In this study we examined the mediating effect of child's cognitive functions on the association between child and epilepsy-related factors and psychosocial problems. Additionally, the differences in psychosocial problems reported by various informants (parents, teachers) in different school settings were explored.

METHODS

Participants were 155 children with epilepsy (50 % girls), age range 5-18 years who completed a brief neuropsychological battery. Parents completed the Child Behavior Checklist (CBCL) and teachers completed the corresponding Teacher's Rating Form (TRF), to assess a child's emotional and behavior problems.

RESULTS

The cognitive profile of the sample was within average to low-average range. Parents and teachers both reported high levels of emotional and behavioral problems, and teachers reported relatively higher levels of symptoms. A mediation effect of cognition on the association between child and epilepsy-related factors (i.e., number of antiseizure medications and illness duration) and child's emotional and behavioral problems was evident only for teachers' reports.

CONCLUSIONS

The results emphasize that the complex interactions between epilepsy, cognition and psychosocial outcomes are perceived differently in diverse contexts by different informants. The incongruities in informants' perceptions regarding the role of cognition in child's psychological state should be acknowledged and incorporated when planning effective educational and rehabilitation interventions for children with epilepsy.

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.

A nationwide, retrospective, data-linkage, cohort study of epilepsy and incident dementia

OBJECTIVE

To determine the association of epilepsy with incident dementia by conducting a nationwide, retrospective data-linkage, cohort study to examine whether the association varies according to dementia subtypes and to investigate whether risk factors modify the association.

METHODS

We used linked health data from hospitalization, mortality records, and primary care consultations to follow up 563,151 Welsh residents from their 60th birthday to estimate dementia rate and associated risk factors. Dementia, epilepsy, and covariates (medication, smoking, comorbid conditions) were classified with the use of previously validated code lists. We studied rate of dementia and dementia subtypes in people with epilepsy (PWE) and without epilepsy using (stratified) Kaplan-Meier plots and flexible parametric survival models.

RESULTS

PWE had a 2.5 (95% confidence interval [CI] 2.3-2.6) times higher hazard of incident dementia, a 1.6 (95% CI 1.4-1.8) times higher hazard of incident Alzheimer disease (AD), and a 3.1 (95% CI 2.8-3.4) times higher hazard of incident Vascular dementia (VaD). A history of stroke modified the increased incidence in PWE. PWE who were first diagnosed at ≤25 years of age had a dementia rate similar to that of those diagnosed later in life. PWE who had ever been prescribed sodium valproate compared to those who had not were at higher risk of dementia (hazard ratio [HR] 1.6, 99% CI 1.4-1.9) and VaD (HR 1.7, 99% CI 1.4-2.1) but not AD (HR 1.2, 99% CI 0.9-1.5).

CONCLUSION

PWE compared to those without epilepsy have an increased dementia risk.

Response of spike-wave discharges in aged APP/PS1 Alzheimer model mice to antiepileptic, metabolic and cholinergic drugs

Epileptic nonconvulsive spike-wave discharges (SWDs) are commonly seen in amyloid plaque bearing transgenic mice but only rarely in their wild-type littermates. To shed light on their possible treatment options, we assessed the effect of drugs with variable and known mechanisms of action on the occurrence of SWDs in aged APPswe/PS1dE9 mice. The treatments included prototypic antiepileptic drugs (ethosuximide and levetiracetam), donepezil as the typical Alzheimer drug and atropine as an antagonistic effect, GABA_B antagonist CGP-35348, and alternate energy substrates beta-hydroxybutyrate (BHB), pyruvate and lactate on the occurrence of SWDs in aged APPswe/PS1dE9 mice. All agents were administered by single intraperitoneal injections at doses earlier documented to be effective and response was assessed by recording 3 h of video-EEG. Atropine at 25 mg/kg significantly decreased SWD occurrence in all behavioral states, and also resulted in altered frequency composition of SWDs and general EEG slowing during sleep. Ethosuximide at 200 mg/kg and levetiracetam at 75 mg/kg effectively suppressed SWDs only during a period of mixed behavioral states, but levetiracetam also increased SWDs in sleep. BHB at 1 g/kg decreased SWDs in sleep, while both pyruvate and lactate at the same dose tended to increase SWD number and total duration. Unexpectantly, donepezil at 0.3 mg/kg CGP-35348 at 100 mg/kg had no effect on SWDs. These findings call for re-evaluation of some prevailing theories on neural circuit alternations that underlie SWD generation and show the utility of APP/PS1 mice for testing potential new treatments for nonconvulsive epileptic activity related to Alzheimer pathology.

High-frequency electrical stimulation of the anterior thalamic nuclei increases vigilance in epilepsy patients during relaxed and drowsy wakefulness

OBJECTIVE

High-frequency deep brain stimulation (DBS) of anterior thalamic nuclei (ANT) reduces the frequency and intensity of focal and focal to bilateral tonic-clonic epileptic seizures. We investigated the impact of high-frequency ANT-DBS on vigilance in epilepsy patients during relaxed and drowsy wakefulness, to better understand the effects and the mechanisms of action of this intervention in humans.

METHODS

Four patients with different structural epileptic pathologies were included in this retrospective case-cohort study. Short- and long-term electroencephalography (EEG) was used to determine states of relaxed or drowsy wakefulness and the vigilance changes during stimulation-on and stimulation-off intervals.

RESULTS

In relaxed, wakeful patients with eyes closed, the eyelid artifact rate increased acutely and reproducibly during stimulation-on intervals, suggesting an enhanced vigilance. This effect was accompanied by a slight acceleration of the alpha rhythm. In drowsy patients with eyes closed, stimulation generated acutely and reproducibly alpha rhythms, similar to the paradoxical alpha activation during eyes opening. The occurrence of the alpha rhythms reflected an increase in the vigilance of the drowsy subjects during ANT-DBS.

SIGNIFICANCE

This is the first demonstration that ANT-DBS increases the vigilance of wakeful epilepsy patients. Our results deliver circumstantial evidence that high-frequency ANT-DBS activates thalamocortical connections that promote wakefulness.

GSK3β and Tau Protein in Alzheimer's Disease and Epilepsy

Alzheimer's disease (AD) is the most common form of dementia present in older adults; its etiology involves genetic and environmental factors. In recent years, epidemiological studies have shown a correlation between AD and chronic epilepsy since a considerable number of patients with AD may present seizures later on. Although the pathophysiology of seizures in AD is not completely understood, it could represent the result of several molecular mechanisms linked to amyloid beta-peptide (Aβ) accumulation and the hyperphosphorylation of tau protein, which may induce an imbalance in the release and recapture of excitatory and inhibitory neurotransmitters, structural alterations of the neuronal cytoskeleton, synaptic loss, and neuroinflammation. These changes could favor the recurrent development of hypersynchronous discharges and epileptogenesis, which, in a chronic state, favor the neurodegenerative process and influence the cognitive decline observed in AD. Supporting this correlation, histopathological studies in the brain tissue of temporal lobe epilepsy (TLE) patients have revealed the presence of Aβ deposits and the accumulation of tau protein in the neurofibrillary tangles (NFTs), accompanied by an increase of glycogen synthase kinase-3 beta (GSK3β) activity that may lead to an imminent alteration in posttranslational modifications of some microtubule-associated proteins (MAPs), mainly tau. The present review is focused on understanding the pathological aspects of GSK3β and tau in the development of TLE and AD.

Four-dimensional map of direct effective connectivity from posterior visual areas

Lower- and higher-order visual cortices in the posterior brain, ranging from the medial- and lateral-occipital to fusiform regions, are suggested to support visual object recognition, whereas the frontal eye field (FEF) plays a role in saccadic eye movements which optimize visual processing. Previous studies using electrophysiology and functional MRI techniques have reported that tasks requiring visual object recognition elicited cortical activation sequentially in the aforementioned posterior visual regions and FEFs. The present study aims to provide unique evidence of direct effective connectivity outgoing from the posterior visual regions by measuring the early component (10-50 ​ms) of cortico-cortical spectral responses (CCSRs) elicited by weak single-pulse direct cortical electrical stimulation. We studied 22 patients who underwent extraoperative intracranial EEG recording for clinical localization of seizure foci and functionally-important brain regions. We used animations to visualize the spatiotemporal dynamics of gamma band CCSRs elicited by stimulation of three different posterior visual regions. We quantified the strength of CCSR-defined effective connectivity between the lower- and higher-order posterior visual regions as well as from the posterior visual regions to the FEFs. We found that effective connectivity within the posterior visual regions was larger in the feedforward (i.e., lower-to higher-order) direction compared to the opposite direction. Specifically, connectivity from the medial-occipital region was largest to the lateral-occipital region, whereas that from the lateral-occipital region was largest to the fusiform region. Among the posterior visual regions, connectivity to the FEF was largest from the lateral-occipital region and the mean peak latency of CCSR propagation from the lateral-occipital region to FEF was 26 ​ms. Our invasive study of the human brain using a stimulation-based intervention supports the model that the posterior visual regions have direct cortico-cortical connectivity pathways in which neural activity is transferred preferentially from the lower-to higher-order areas. The human brain has direct cortico-cortical connectivity allowing a rapid transfer of neural activity from the lateral-occipital region to the FEF.

Thalamocortical structural connectivity abnormalities in drug-resistant generalized epilepsy: A diffusion tensor imaging study

BACKGROUND AND PURPOSE

Epilepsy is one of the most common diseases of the nervous system. Approximately one-third of epilepsy cases are drug-resistant, among which generalized-onset seizures are very common. The present study aimed to analyze abnormalities of the thalamocortical fiber pathways in each hemisphere of the brains of patients with drug-resistant generalized epilepsy.

MATERIALS AND METHODS

The thalamocortical structural pathways were identified by diffusion tensor imaging (DTI) in 15 patients with drug-resistant generalized epilepsy and 16 gender/age-matched controls. The thalami of both groups were parcellated into subregions according to the local thalamocortical connectivity pattern. DTI measures of thalamocortical connections were compared between the two groups.

RESULTS

Probabilistic tractography analyses showed that fractional anisotropy of thalamocortical pathways in patients with epilepsy decreased significantly, and the radial diffusivity of the left thalamus pathways with homolateral motor and parietal-occipital cortical regions in the drug-resistant epilepsy group increased significantly. In addition to the right thalamus pathway and prefrontal cortical region, fractional anisotropy of all other pathways was inversely correlated with disease duration.

CONCLUSION

The results provide evidence indicating widespread bilateral abnormalities in the thalamocortical pathways in epilepsy patients and imply that the degree of abnormality in the pathway increases with the disease duration.

Relative Seizure Relapse Risks Associated with Antiepileptic Drug Withdrawal After Different Seizure-Free Periods in Adults with Focal Epilepsy: A Prospective, Controlled Follow-Up Study

BACKGROUND

Approximately two-thirds of patients with newly diagnosed epilepsy become seizure-free after antiepileptic drug (AED) treatment. A crucial issue for these patients and their families, especially after a long period of seizure freedom, is when to stop their medications.

OBJECTIVE

The aim of this study was to identify the optimal timing of AED withdrawal in adults with focal epilepsy who had been seizure-free for ≥ 2 years.

METHODS

Adults with focal epilepsy who had been seizure-free for ≥ 2 years were recruited. Based on their decision to discontinue (withdrawal) or continue (non-withdrawal) AED treatment, patients were assigned to withdrawal or non-withdrawal subgroups according to the length of remission (2 to < 3 years, 3 to < 4 years, 4 to < 5 years and ≥ 5 years). The relapse risks of the withdrawal and corresponding non-withdrawal subgroups were compared, and the relative relapse risks were assessed in a Cox proportional hazard regression model.

RESULTS

A total of 213 eligible patients began to withdraw from AED treatment; 70 had been seizure-free for 2 to < 3 years, 62 had been seizure-free for 3 to < 4 years, 37 had been seizure-free for 4 to < 5 years and 44 had been seizure-free for ≥ 5 years. The figures for the corresponding non-withdrawal subgroups were 463, 334, 251 and 182, respectively. There was a significantly higher risk of seizure relapse in patients withdrawing from AEDs after 2 to < 5 years of seizure freedom than in the corresponding non-withdrawal controls, and the relative relapse risk was 3.052 (95% confidence interval [CI] 2.126-4.381; p < 0.001) for the seizure-free period of 2 to < 3 years, 3.617 (95% CI 2.384-5.488; p < 0.001) for 3 to < 4 years and 2.644 (95% CI 1.456-4.799; p = 0.001) for 4 to < 5 years. However, for patients who were seizure-free for ≥ 5 years, AED withdrawal did not significantly increase the risk of seizure relapse compared with that of patients continuing treatment (hazard ratio [HR] 1.362, 95% CI 0.634-2.926, p = 0.428). Compared with a seizure-free period of 2 to < 3 years, the relative relapse risk after AED withdrawal was significantly reduced only after being seizure-free for ≥ 5 years (HR 0.441, 95% CI 0.233-0.834; p = 0.012).

CONCLUSION

Overall, for adults with focal epilepsy, withdrawal from AEDs significantly increased the risk of seizure relapse after being seizure-free for 2 to < 5 years, but might not increase the risk if the seizure-free period was ≥ 5 years.

Panayiotopoulos syndrome and Gastaut syndrome are distinct entities in terms of neuropsychological findings

BACKGROUND

Although the courses of self-limited focal epilepsies of childhood are considered as benign, a handful of studies suggested that these children may suffer from cognitive problems. Implementing tailor-made educational strategies would aid these children to reach their full potentials. Therefore, it is crucial to understand and differentiate the complete neuropsychological and behavioral profiles of these rather common syndromes. We aimed to examine the distinct cognitive and behavioral profiles of the Panayiotopoulos syndrome (PS) and the Gastaut syndrome (GS), comparatively.

METHOD

Twenty patients with PS, 20 patients with GS, and 20 healthy controls have been recruited. The testing protocol included Wechsler Intelligence Scale for Children-Revised, Conner's Continuous Performance Test, Verbal Fluency Test, Stroop Color and Word Test, Color Trails Test, Tower of London Test, Symbol Digit Modalities Test, California Verbal Learning Test-Children's Version, Rey Complex Figure Test, Benton Face Recognition Test, Benton Judgment of Line Orientation, Peabody Picture Vocabulary Test, Reading and Writing Test, Child Behavior Checklist, Conner's Parent Rating Scale-48, and Behavior Rating Inventory of Executive Function. Demographical, clinical, electrophysiological data, and imaging findings have also been evaluated.

RESULTS

With regard to intelligence, the patients with PS scored less in all scales compared to the healthy controls. However, only the performance IQ (intelligence quotient) scores differed significantly between the patient groups, with the patients with PS scoring lower than the patients with GS. Verbal memory problems were eminent in both of the patient groups; whereas, visual memory was impaired only in the group with PS. Psychomotor speed was affected in both groups. Reading problems were prominent only in the patients with PS. Writing and arithmetic skills were defective in both patient groups. There were no noteworthy behavioral problems in comparison to healthy subjects.

CONCLUSION

Using neuropsychological profiles, this study demonstrated that the GS and the PS are two distinct entities. Cognitive dysfunction is a more prominent and widespread feature of the patients with PS; whereas, the patients with GS suffer only from milder and isolated cognitive problems.

Enhancing effect of aerobic training on learning and memory performance in rats after long-term treatment with Lacosamide via BDNF-TrkB signaling pathway

Aerobic training has a neuroprotective effect, reduces the risk of developing neurodegenerative diseases and facilitates functional recovery. The present study assesses the effect of aerobic training on cognitive functions, hippocampal BDNF/TrkB ligand receptor system expression and serum levels of BDNF and corticosterone in intact rats after chronic treatment with Lacosamide (LCM). Male Wistar rats were randomly divided into two groups. One group was exercised on a treadmill (Ex) and the other one was sedentary (Sed). Half of the rats from each group received saline (veh) while the other half - LCM. The rats underwent a month-long training and LCM treatment before being subjected to one active and two passive avoidance tests. Both trained groups increased significantly the number of avoidances compared with the sedentary animals during the learning session and on memory retention tests, while the number of avoidances of the LCM-treated rats was significantly lower in comparison with the saline-treated animals. Both passive avoidance tests revealed that trained animals spent more time in the lighted compartment or caused longer stay on the platform than did the sedentary rats during acquisition and short- and long-term memory retention tests. Aerobic training increased BDNF and TrkB hippocampal immunoreactivity. We found no significant difference between BDNF serum levels but corticosterone levels of the Sed-LCM rats were lower than those of the Sed-veh animals. Our results show that aerobic training increases the hippocampal BDNF/TrkB expression suggesting a role in preventing the negative effect of Lacosamide on cognitive functions in rats.

The efficacy and safety of lamotrigine for absence seizures in children and adolescents: A systematic review and meta-analysis

AIMS

This systematic review and meta-analysis of randomized controlled trials (RCTs) systematically explored the effectiveness and safety of lamotrigine for absence seizures in children and adolescents.

METHODS

Keywords searches were conducted in Pubmed Embase Cochrane Central Register of Controlled Trials Wanfang CNKI from inception through March 2019. The RCTs comparing lamotrigine with other drugs and/or placebo for the treatment of absence seizures in children and adolescents were considered in this study. The study was conducted adhering to PRISMA guidelines.

RESULTS

Eight RCTs (n = 787) were included in our study. Among these studies, one study (N = 45 patients) used placebo as a control and seven studies (N = 742 patients) used positive drug controls. For effectiveness, there was significant difference between lamotrigine and valproate [OR = 0.42, 95%CI (0.28-0.63), I² = 0%] or ethosuximide [OR = 0.34, 95%CI (0.22-0.53), I² = 0%]. For adverse effects (AEs), there was no significant difference between lamotrigine and valproate [OR = 1.17, 95%CI (0.59, 2.32), I² = 0%] or ethosuximide [OR = 0.75, 95%CI (0.47, 1.19), I² = 92%], and the most common adverse effects of lamotrigine were Rash (7.88%), Fatigue (6.50%) and Headache (6.50%).

CONCLUSIONS

According to current evidence, LTG is less effective than VPA and ESM, however, based on its relative safety, LTG might be reasonably tried as initial therapy in children and adolescents at risk of significant adverse effects from VPA and ESM, and future well-designed studies are needed to confirm our findings.

Music training is neuroprotective for verbal cognition in focal epilepsy

Focal epilepsy is a unilateral brain network disorder, providing an ideal neuropathological model with which to study the effects of focal neural disruption on a range of cognitive processes. While language and memory functions have been extensively investigated in focal epilepsy, music cognition has received less attention, particularly in patients with music training or expertise. This represents a critical gap in the literature. A better understanding of the effects of epilepsy on music cognition may provide greater insight into the mechanisms behind disease- and training-related neuroplasticity, which may have implications for clinical practice. In this cross-sectional study, we comprehensively profiled music and non-music cognition in 107 participants; musicians with focal epilepsy (n = 35), non-musicians with focal epilepsy (n = 39), and healthy control musicians and non-musicians (n = 33). Parametric group comparisons revealed a specific impairment in verbal cognition in non-musicians with epilepsy but not musicians with epilepsy, compared to healthy musicians and non-musicians (P = 0.029). This suggests a possible neuroprotective effect of music training against the cognitive sequelae of focal epilepsy, and implicates potential training-related cognitive transfer that may be underpinned by enhancement of auditory processes primarily supported by temporo-frontal networks. Furthermore, our results showed that musicians with an earlier age of onset of music training performed better on a composite score of melodic learning and memory compared to non-musicians (P = 0.037), while late-onset musicians did not differ from non-musicians. For most composite scores of music cognition, although no significant group differences were observed, a similar trend was apparent. We discuss these key findings in the context of a proposed model of three interacting dimensions (disease status, music expertise, and cognitive domain), and their implications for clinical practice, music education, and music neuroscience research.

Uncertain Effectiveness of Prophylactic Anticonvulsive Medication in Predicting Cognitive Outcome of Neurosurgical Patients

OBJECTIVES

To evaluate the influence of prophylactic anticonvulsive medication, above all levetiracetam monotherapy, in predicting the cognitive outcome of neurosurgical patients with post-traumatic brain injury, intracerebral hemorrhage, and encephalic tumors.

METHODS

We examined data concerning 232 of 327 adult patients admitted to the Neurorehabilitation Department of the San Raffaele Hospital (Milan, Italy) after discharge from the Neurosurgery Department. Cognitive status was evaluated by means of the "Mini-Mental State" examination and the Functional Independence Measure at baseline and at the end of a rehabilitation care with an average duration of about four weeks.

RESULTS

The vast majority of the patients were treated with levetiracetam. Our data showed a negative role of antiepileptic drugs on cognitive recovery in a cohort of neurosurgical patients.

CONCLUSIONS

Knowing thoroughly the effects of antiepileptic drugs in rehabilitation outcome is of fundamental importance. This study represents the only large series analyzing these aspects in the rehabilitation of neurosurgical patients. Antiepileptic drugs should be managed to ensure patients the best possible cognitive outcome. Further evidence from good-quality trials is required to assess the clinical effectiveness of prophylactic anticonvulsive medication in predicting the cognitive outcome of neurosurgical patients who are treated with rehabilitation.