Cognitive impairment in epilepsy: the role of network abnormalities

Persistent ∆FosB expression limits recurrent seizure activity and provides neuroprotection in the dentate gyrus of APP mice

Recurrent seizures lead to accumulation of the activity-dependent transcription factor ∆FosB in hippocampal dentate granule cells in both mouse models of epilepsy and mouse models of Alzheimer's disease (AD), which is also associated with increased incidence of seizures. In patients with AD and related mouse models, the degree of ∆FosB accumulation corresponds with increasing severity of cognitive deficits. We previously found that ∆FosB impairs spatial memory in mice by epigenetically regulating expression of target genes such as calbindin that are involved in synaptic plasticity. However, the suppression of calbindin in conditions of neuronal hyperexcitability has been demonstrated to provide neuroprotection to dentate granule cells, indicating that ∆FosB may act over long timescales to coordinate neuroprotective pathways. To test this hypothesis, we used viral-mediated expression of ∆JunD to interfere with ∆FosB signaling over the course of several months in transgenic mice expressing mutant human amyloid precursor protein (APP), which exhibit spontaneous seizures and develop AD-related neuropathology and cognitive deficits. Our results demonstrate that persistent ∆FosB activity acts through discrete modes of hippocampal target gene regulation to modulate neuronal excitability, limit recurrent seizure activity, and provide neuroprotection to hippocampal dentate granule cells in APP mice.

Psychological Therapy for Functional Neurological Disorder: Examining Impact on Dissociation, Psychological Distress and General Functioning

Functional neurological disorder (FND) represents a broad group of motor and sensory clinical symptoms which cannot be explained by other neurological diagnoses. Dissociation is considered a key mechanism in their development and maintenance. Despite psychological therapy being the recommended choice of treatment for FND, evidence for its effectiveness is in its infancy. This study explored the dissociative profile of forty-seven patients with FND and evaluated whether individual psychological therapy improved dissociative symptoms, psychological distress and general functioning among twenty-five adults with FND. Patients completed the Multiscale Dissociation Inventory, the EuroQol five-dimensional descriptive system, the General Anxiety Disorder-7 scale and the Patient Health Questionnaire-9. Our sample showed high levels of disengagement, depersonalization and memory disturbance at baseline. Treatment was associated with significant improvements in general functioning, and symptoms of dissociation and anxiety. Improvements in dissociative experiences were found to be possibly due to reduction in anxiety. Improvements in depression were the strongest predictor of improvements in general functioning. Limitations and areas for further research are discussed.

A Systematic Review of Semaglutide's Influence on Cognitive Function in Preclinical Animal Models and Cell-Line Studies

Since we aim to test new options to find medication for cognitive disorders, we have begun to assess the effect of semaglutide and to conduct a review gathering studies that have attempted this purpose. This systematic review focuses on the cognitive effects of semaglutide, a glucagon-like peptide 1 receptor agonist (GLP-1 RA), in the context of neurological and cognitive impairment. Semaglutide, a synthetic GLP-1 analog, showcased neuroprotective effects beyond metabolic regulation. It mitigated apoptosis and improved cognitive dysfunction in cerebrovascular disease, suggesting broader implications for neurological well-being. Also, studies highlighted GLP-1 RAs' positive impact on olfactory function in obese individuals with type 2 diabetes, on neurodegenerative disorders, multiple sclerosis, and endotoxemia. In order to analyze current studies that assess the impact of semaglutide on cognitive function, a literature search was conducted up to February 2024 on two online databases, MEDLINE (via PubMed) and Web of Science Core Collection, as well as various websites. Fifteen studies on mice populations and two studies on cell lines were included, analyzed, and assessed with bias-specific tools. The neuroprotective and anti-apoptotic properties of GLP-1 and its analogs were emphasized, with animal models and cell line studies demonstrating enhanced cognitive function. While promising, limitations include fewer studies, highlighting the need for extensive research, particularly in the human population. Even though this medication seems promising, there are significant limitations, one of which is the lack of studies on human subjects. Therefore, this review aims to gather current evidence.

Amygdala and cortical gamma-band responses to emotional faces are modulated by attention to valence

The amygdala might support an attentional bias for emotional faces. However, whether and how selective attention toward a specific valence modulates this bias is not fully understood. Likewise, it is unclear whether amygdala and cortical signals respond to emotion and attention in a similar way. We recorded gamma-band activity (GBA, > 30 Hz) intracranially in the amygdalae of 11 patients with epilepsy and collected scalp recordings from 19 healthy participants. We presented angry, neutral, and happy faces randomly, and we denoted one valence as the target. Participants detected happy targets most quickly and accurately. In the amygdala, during attention to negative faces, low gamma-band activity (LGBA, < 90 Hz) increased for angry compared with happy faces from 160 ms. From 220 ms onward, amygdala high gamma-band activity (HGBA, > 90 Hz) was higher for angry and neutral faces than for happy ones. Monitoring neutral faces increased amygdala HGBA for emotions compared with neutral faces from 40 ms. Expressions were not differentiated in GBA while monitoring positive faces. On the scalp, only threat monitoring resulted in expression differentiation. Here, posterior LGBA was increased selectively for angry targets from 60 ms. The data show that GBA differentiation of emotional expressions is modulated by attention to valence: Top-down-controlled threat vigilance coordinates widespread GBA in favor of angry faces. Stimulus-driven emotion differentiation in amygdala GBA occurs during a neutral attentional focus. These findings align with a multi-pathway model of emotion processing and specify the role of GBA in this process.

Remote neuropsychological assessment of patients with neurological disorders and injuries-a study protocol for a cross-sectional case-control validation study

INTRODUCTION

There are great potential benefits of being able to conduct neuropsychological assessments remotely, especially for hard-to-reach or less mobile patient groups. Such tools need to be equivalent to standard tests done in the clinic and also easy to use in a variety of clinical populations.

METHODS AND ANALYSIS

This study protocol describes a cross-sectional study aimed at validating the newly developed digitalized neuropsychological test battery Mindmore Remote in patients with neurological disorders and injuries. Diagnoses comprise traumatic brain injury, stroke, Parkinson's disease, multiple sclerosis, brain tumour and epilepsy. 50 patients in each patient group will be included. In addition, 50 healthy controls will be recruited. All participants will undergo both testing with Mindmore Remote at home and traditional neuropsychological assessment face-to-face in a randomised order. The primary outcome is the association between tests from the Mindmore Remote battery and their equivalent traditional neuropsychological tests. Further, bias between methods and differences between groups will also be investigated.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Swedish Ethical Review Authority (2022-06230-01) and adheres to the declaration of Helsinki. All participants will be given oral and written information about the study and sign informed consent forms before entering the study. All participants are informed that they can terminate their participation in the study at any given time, without giving any explanation, and participating in the study or not will not affect their care at the clinic. Neither authors nor personnel involved in the research project are affiliated with Mindmore AB. The results from the study will be published in peer-reviewed scientific journals and presented at national and international conferences on the topic.

TRIAL REGISTRATION NUMBER

NCT05819008.

Experiences of using the MINDSET Self-Management mobile health app among Hispanic Patients:Results of a qualitative study

BACKGROUND

Interventions focusing on epilepsy self-management (ESM) are vital for promoting the health of people living with epilepsy. E-technology and mobile health (mHealth) tools are becoming increasingly integrated into practice to promote self-management strategies for chronic diseases, enhance care delivery, and reduce health disparities. Management Information and Decision Support Epilepsy Tool (MINDSET), a bilingual decision support tool (available in English and Spanish), was found to be both feasible and effective in facilitating goal-based ESM in the clinic.

PURPOSE

To assess the experience of using MINDSET as an ESM intervention among Hispanic patients with epilepsy to inform future interventional studies.

METHODS

This study used a Qualitative Descriptive (QD) framework to provide a rich and straightforward description of patients' subjective experiences using MINDSET. Participants were enrolled in the intervention group of a larger parent study (RCT) to assess the efficacy of MINDSET among Hispanic People with Epilepsy (PWE). The purposive, convenient, criterion-based sample for this qualitative analysis comprised of 42 patients who agreed to participate in a semi-structured interview at the end of the larger RCT. This RCT was conducted between August 2017 and January 2019. Spanish and English-speaking Hispanic adult patients (n = 94) with epilepsy in Arizona (n = 53) and Texas (n = 41) were randomly assigned within 6 neurology clinics to treatment (MINDSET plus Usual Care, hereafter referred to as MINDSET; n = 46) and comparison (Usual Care Only; n = 48) conditions.

RESULTS

Patient demographics, epilepsy conditions, and ESM behavioral characteristics were representative of the intervention group. Study participants were Hispanic, mainly of Mexican descent (94 %), with a mean age of 39 years, mostly female (53 %), and most of the participants reported having had one or more seizures per month (54 %). The MINDSET intervention revealed five ESM themes: (1) Awareness and Realization of Epilepsy Self-Management, (2) Communication and Partnership with Health Care Providers HCP, (3) Epilepsy Self-Management and Quality of Life, (4) Seizure Control, and (5) Optimism and Agency.

CONCLUSION

The participants who used MINDSET as a self-management intervention reported an overall positive experience. Qualitative data in this study show that MINDSET is a valuable ESM tool for Hispanic patients with epilepsy. Findings from this qualitative study were consistent with results from a larger parent study that recognized MINDSET as an effective platform for improving epilepsy self-management adherence.

Chronological transitions of hepatocyte growth factor treatment effects in spinal cord injury tissue

Inflammatory responses are known to suppress neural regeneration in patients receiving stem cell-based regenerative therapy for spinal cord injury (SCI). Consequently, pathways involved in neurogenesis and immunomodulation, such as the hepatocyte growth factor (HGF)/MET signaling cascade, have garnered significant attention. Notably, various studies, including our own, have highlighted the enhanced recovery of locomotor functions achieved in SCI animal models by combining HGF pretreatment and human induced stem cell-derived neural stem/progenitor cell (hiPSC-NS/PC) transplantation. However, these studies implicitly hypothesized that the functionality of HGF in SCI would be time consistent and did not elucidate its dynamics. In the present article, we investigated the time-course of the effect of HGF on SCI, aiming to uncover a more precise mechanism for HGF administration, which is indispensable for developing crystallizing protocols for combination therapy. To this end, we performed a detailed investigation of the temporal variation of HGF using the RNA-seq data we obtained in our most recent study. Leveraging the time-series design of the data, which we did not fully exploit previously, we identified three components in the effects of HGF that operate at different times: early effects, continuous effects, and delayed effects. Our findings suggested a concept where the three components together contribute to the acceleration of neurogenesis and immunomodulation, which reinforce the legitimacy of empirically fine-tuned protocols for HGF administration and advocate the novel possibility that the time-inconsistent effects of HGF progressively augment the efficacy of combined therapy.

Rodents' visual gamma as a biomarker of pathological neural conditions

Neural gamma oscillations (indicatively 30-100 Hz) are ubiquitous: they are associated with a broad range of functions in multiple cortical areas and across many animal species. Experimental and computational works established gamma rhythms as a global emergent property of neuronal networks generated by the balanced and coordinated interaction of excitation and inhibition. Coherently, gamma activity is strongly influenced by the alterations of synaptic dynamics which are often associated with pathological neural dysfunctions. We argue therefore that these oscillations are an optimal biomarker for probing the mechanism of cortical dysfunctions. Gamma oscillations are also highly sensitive to external stimuli in sensory cortices, especially the primary visual cortex (V1), where the stimulus dependence of gamma oscillations has been thoroughly investigated. Gamma manipulation by visual stimuli tuning is particularly easy in rodents, which have become a standard animal model for investigating the effects of network alterations on gamma oscillations. Overall, gamma in the rodents' visual cortex offers an accessible probe on dysfunctional information processing in pathological conditions. Beyond vision-related dysfunctions, alterations of gamma oscillations in rodents were indeed also reported in neural deficits such as migraine, epilepsy and neurodegenerative or neuropsychiatric conditions such as Alzheimer's, schizophrenia and autism spectrum disorders. Altogether, the connections between visual cortical gamma activity and physio-pathological conditions in rodent models underscore the potential of gamma oscillations as markers of neuronal (dys)functioning.

Neuropsychological characteristics of drug resistant epilepsy patients with and without comorbid functional seizures

INTRODUCTION

Neuropsychological testing is a mandatory component in the evaluation of drug resistant epilepsy. The results of testing may assist with both the localization of an epilepsy as well as assessment of surgical risk. Previous studies have demonstrated differences in the neuropsychological performance of patients with epilepsy and functional seizures. We hypothesized that comorbid functional seizures could potentially influence neuropsychological test performance. Therefore, we evaluated whether there is a difference in the neuropsychological test results between drug resistant epilepsy patients with and without comorbid functional seizures.

METHOD

Neuropsychological test results were compared between 25 patients with drug resistant focal epilepsy and 25 patients that also had documented functional seizures. Univariate analyses and multiple logistic regression models were used to both assess performance differences between the groups and to assess whether test results could be used to accurately identify which patients had comorbid functional seizures.

RESULTS

Epilepsy patients with comorbid functional seizures performed significantly worse on the FAS Verbal Fluency Test compared to ES patients (p = 0.047). Digit Span Backwards (p = 0.10), Digit Span Forwards (p = 0.14) and Working Memory Index (p = 0.10) tended to be lower in the epilepsy and functional seizures group but was not statistically significant. A multiple logistic regression model using the results of four neuropsychological tests was able to identify patients with comorbid functional seizures with 83.33% accuracy.

CONCLUSIONS

There are appeared to be some differences in the neuropsychological performance among drug resistant epilepsy patients based on whether they have comorbid functional seizures. These findings may have relevant implications for the interpretation of neuropsychological test results.

Effect of the closed-loop hippocampal low-frequency stimulation on seizure severity, learning, and memory in pilocarpine epilepsy rat model

AIMS

In this study, the anticonvulsant action of closed-loop, low-frequency deep brain stimulation (DBS) was investigated. In addition, the changes in brain rhythms and functional connectivity of the hippocampus and prefrontal cortex were evaluated.

METHODS

Epilepsy was induced by pilocarpine in male Wistar rats. After the chronic phase, a tripolar electrode was implanted in the right ventral hippocampus and a monopolar electrode in medial prefrontal cortex (mPFC). Subjects' spontaneous seizure behaviors were observed in continuous video recording, while the local field potentials (LFPs) were recorded simultaneously. In addition, spatial memory was evaluated by the Barnes maze test.

RESULTS

Applying hippocampal DBS, immediately after seizure detection in epileptic animals, reduced their seizure severity and duration, and improved their performance in Barnes maze test. DBS reduced the increment in power of delta, theta, and gamma waves in pre-ictal, ictal, and post-ictal periods. Meanwhile, DBS increased the post-ictal-to-pre-ictal ratio of theta band. DBS decreased delta and increased theta coherences, and also increased the post-ictal-to-pre-ictal ratio of coherence. In addition, DBS increased the hippocampal-mPFC coupling in pre-ictal period and decreased the coupling in the ictal and post-ictal periods.

CONCLUSION

Applying closed-loop, low-frequency DBS at seizure onset reduced seizure severity and improved memory. In addition, the changes in power, coherence, and coupling of the LFP oscillations in the hippocampus and mPFC demonstrate low-frequency DBS efficacy as an antiepileptic treatment, returning LFPs to a seemingly non-seizure state in subjects that received DBS.

Implementation of a 7T Epilepsy Task Force consensus imaging protocol for routine presurgical epilepsy work-up: effect on diagnostic yield and lesion delineation

OBJECTIVE

Recently, the 7 Tesla (7 T) Epilepsy Task Force published recommendations for 7 T magnetic resonance imaging (MRI) in patients with pharmaco-resistant focal epilepsy in pre-surgical evaluation. The objective of this study was to implement and evaluate this consensus protocol with respect to both its practicability and its diagnostic value/potential lesion delineation surplus effect over 3 T MRI in the pre-surgical work-up of patients with pharmaco-resistant focal onset epilepsy.

METHODS

The 7 T MRI protocol consisted of T1-weighted, T2-weighted, high-resolution-coronal T2-weighted, fluid-suppressed, fluid-and-white-matter-suppressed, and susceptibility-weighted imaging, with an overall duration of 50 min. Two neuroradiologists independently evaluated the ability of lesion identification, the detection confidence for these identified lesions, and the lesion border delineation at 7 T compared to 3 T MRI.

RESULTS

Of 41 recruited patients > 12 years of age, 38 were successfully measured and analyzed. Mean detection confidence scores were non-significantly higher at 7 T (1.95 ± 0.84 out of 3 versus 1.64 ± 1.19 out of 3 at 3 T, p = 0.050). In 50% of epilepsy patients measured at 7 T, additional findings compared to 3 T MRI were observed. Furthermore, we found improved border delineation at 7 T in 88% of patients with 3 T-visible lesions. In 19% of 3 T MR-negative cases a new potential epileptogenic lesion was detected at 7 T.

CONCLUSIONS

The diagnostic yield was beneficial, but with 19% new 7 T over 3 T findings, not major. Our evaluation revealed epilepsy outcomes worse than ILAE Class 1 in two out of the four operated cases with new 7 T findings.

Epilepsy is more than a simple seizure disorder: Causal relationships between epilepsy and its comorbidities

This review draws connections between the pathogenesis of canine epilepsy and its most commonly recognised comorbidities: cognitive impairment (CI), attention deficit hyperactivity disorder (ADHD)-like behaviour, fear and anxiety. Uni/bidirectional causalities and the possibility of a common aetiology triggering both epilepsy and the associated diseases are considered. Research on this topic is sparse in dogs, so information has been gathered and assessed from human and laboratory animal studies. Anatomical structures, functional connections, disrupted neurotransmission and neuroinflammatory processes collectively serve as a common foundation for epilepsy and its comorbidities. Specific anatomical structures, especially parts of the limbic system, such as the amygdala and the hippocampus, are involved in generating seizures, as well as cognitive- and behavioural disorders. Furthermore, disturbances in inhibitory and excitatory neurotransmission influence neuronal excitability and networks, leading to underlying brain dysfunction. Functional magnetic resonance imaging (fMRI), interictal epileptiform discharges (IEDs), and electroencephalography (EEG) have demonstrated functional brain connections that are related to the emergence of both epilepsy and its various comorbidities. Neuroinflammatory processes can either cause or be a consequence of seizures, and inflammatory mediators, oxidative stress and mitochondrial dysfunction, can equally evoke mood disorders. The extensive relationships contributing to the development and progression of seizures and comorbid cognitive and behavioural conditions illustrate the complexity of the disease that is epilepsy.

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.

Adansonia digitata L. Stem Bark Attenuates Epileptic Seizure, Depression, and Neurodegeneration by Mediating GABA and Glutamate in Pentylenetetrazol-Kindled Rats

Objectives

Epilepsy is a neurological condition characterized by repeated seizures attributable to synchronous neuronal activity in the brain. The study evaluated the effect of acetone extract of Adansonia digitata stem bark (ASBE) on seizure score, cognition, depression, and neurodegeneration as well as the level of Gamma-Aminobutyrate acid (GABA) and glutamate in Pentylenetetrazol-kindled rats.

Methods

Thirty-five rats were assigned into five groups (n = 7). Groups 1-2 received normal saline and 35 mg/kg PTZ every other day. Groups 3-4 received 125 mg/kg and 250 mg/kg ASBE orally while group 5 received 5 mg/kg diazepam daily for twenty-six days. Group 3-5 received PTZ every other day, 30 mins after ASBE and diazepam.

Results

The results showed that Pentylenetetrazol (PTZ) induces seizure, reduces mobility time in force swim test and decreases the normal cell number in the brain. It also significantly decreases (p < 0.05) catalase, superoxide dismutase and reduced glutathione activities compared to the ASBE pre-treated rats. Pre-treatment with ASBE reportedly decreases seizure activities significantly (p < 0.05) and increases mobility time in the force swim test. ASBE also significantly elevate (p < 0.05) the normal cell number in the hippocampus, temporal lobe, and dentate gyrus.

Conclusion

ASBE reduced seizure activity and prevented depression in PTZ-treated rats. It also prevented neurodegeneration by regulating glutamate and GABA levels in the brain as well as preventing lipid peroxidation.

An update on the seizures beget seizures theory

Seizures beget seizures is a longstanding theory that proposed that seizure activity can impact the structural and functional properties of the brain circuits in ways that contribute to epilepsy progression and the future occurrence of seizures. Originally proposed by Gowers, this theory continues to be quoted in the pathophysiology of epilepsy. We critically review the existing data and observations on the consequences of recurrent seizures on brain networks and highlight a range of factors that speak for and against the theory. The existing literature demonstrates clearly that ictal activity, especially if recurrent, induces molecular, structural, and functional changes including cell loss, connectivity reorganization, changes in neuronal behavior, and metabolic alterations. These changes have the potential to modify the seizure threshold, contribute to disease progression, and recruit wider areas of the epileptic network into epileptic activity. Repeated seizure activity may, thus, act as a pathological positive-feedback mechanism that increases seizure likelihood. On the other hand, the time course of self-limited epilepsies and the presence of seizure remission in two thirds of epilepsy cases and various chronic epilepsy models oppose the theory. Experimental work showed that seizures could induce neural changes that increase the seizure threshold and decrease the risk of a subsequent seizure. Due to the complex nature of epilepsies, it is wrong to consider only seizures as the key factor responsible for disease progression. Epilepsy worsening can be attributed to the various forms of interictal epileptiform activity or underlying disease mechanisms. Although seizure activity can negatively impact brain structure and function, the "seizures beget seizures" theory should not be used dogmatically but with extreme caution.

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

INTRODUCTION

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

METHOD

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

RESULTS

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

CONCLUSION

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

Functional brain connectivity in young adults with post-stroke epilepsy

Approximately 1 in 10 young stroke patients (18-50 years) will develop post-stroke epilepsy, which is associated with cognitive impairment. While previous studies have shown altered brain connectivity in patients with epilepsy, little is however known about the changes in functional brain connectivity in young stroke patients with post-stroke epilepsy and their relationship with cognitive impairment. Therefore, we aimed to investigate whether young ischaemic stroke patients have altered functional networks and whether this alteration is related to cognitive impairment. We included 164 participants with a first-ever cerebral infarction at young age (18-50 years), along with 77 age- and sex-matched controls, from the Follow-Up of Transient Ischemic Attack and Stroke patients and Unelucidated Risk Factor Evaluation study. All participants underwent neuropsychological testing and resting-state functional MRI to generate functional connectivity networks. At follow-up (10.5 years after the index event), 23 participants developed post-stroke epilepsy. Graph theoretical analysis revealed functional network reorganization in participants with post-stroke epilepsy, in whom a weaker (i.e. network strength), less-integrated (i.e. global efficiency) and less-segregated (i.e. clustering coefficient and local efficiency) functional network was observed compared with the participants without post-stroke epilepsy group and the controls (P < 0.05). Regional analysis showed a trend towards decreased clustering coefficient, local efficiency and nodal efficiency in contralesional brain regions, including the caudal anterior cingulate cortex, posterior cingulate cortex, precuneus, superior frontal gyrus and insula in participants with post-stroke epilepsy compared with those without post-stroke epilepsy. Furthermore, participants with post-stroke epilepsy more often had impairment in the processing speed domain than the group without post-stroke epilepsy, in whom the network properties of the precuneus were positively associated with processing speed performance. Our findings suggest that post-stroke epilepsy is associated with functional reorganization of the brain network after stroke that is characterized by a weaker, less-integrated and less-segregated brain network in young ischaemic stroke patients compared with patients without post-stroke epilepsy. The contralesional brain regions, which are mostly considered as hub regions, might be particularly involved in the altered functional network and may contribute to cognitive impairment in post-stroke epilepsy patients. Overall, our findings provide additional evidence for a potential role of disrupted functional network as underlying pathophysiological mechanism for cognitive impairment in patients with post-stroke epilepsy.

Perturbed Information Processing Complexity in Experimental Epilepsy

Comorbidities, such as cognitive deficits, which often accompany epilepsies, constitute a basal state, while seizures are rare and transient events. This suggests that neural dynamics, in particular those supporting cognitive function, are altered in a permanent manner in epilepsy. Here, we test the hypothesis that primitive processes of information processing at the core of cognitive function (i.e., storage and sharing of information) are altered in the hippocampus and the entorhinal cortex in experimental epilepsy in adult, male Wistar rats. We find that information storage and sharing are organized into substates across the stereotypic states of slow and theta oscillations in both epilepsy and control conditions. However, their internal composition and organization through time are disrupted in epilepsy, partially losing brain state selectivity compared with controls, and shifting toward a regimen of disorder. We propose that the alteration of information processing at this algorithmic level of computation, the theoretical intermediate level between structure and function, may be a mechanism behind the emergent and widespread comorbidities associated with epilepsy, and perhaps other disorders.SIGNIFICANCE STATEMENT Comorbidities, such as cognitive deficits, which often accompany epilepsies, constitute a basal state, while seizures are rare and transient events. This suggests that neural dynamics, in particular those supporting cognitive function, are altered in a permanent manner in epilepsy. Here, we show that basic processes of information processing at the core of cognitive function (i.e., storage and sharing of information) are altered in the hippocampus and the entorhinal cortex (two regions involved in memory processes) in experimental epilepsy. Such disruption of information processing at the algorithmic level itself could underlie the general performance impairments in epilepsy.

Electroencephalography and mild cognitive impairment research: A scoping review and bibliometric analysis (ScoRBA)

Mild cognitive impairment (MCI) is often considered a precursor to Alzheimer's disease (AD) and early diagnosis may help improve treatment effectiveness. To identify accurate MCI biomarkers, researchers have utilized various neuroscience techniques, with electroencephalography (EEG) being a popular choice due to its low cost and better temporal resolution. In this scoping review, we analyzed 2310 peer-reviewed articles on EEG and MCI between 2012 and 2022 to track the research progress in this field. Our data analysis involved co-occurrence analysis using VOSviewer and a Patterns, Advances, Gaps, Evidence of Practice, and Research Recommendations (PAGER) framework. We found that event-related potentials (ERP), EEG, epilepsy, quantitative EEG (QEEG), and EEG-based machine learning were the primary research themes. The study showed that ERP/EEG, QEEG, and EEG-based machine learning frameworks provide high-accuracy detection of seizure and MCI. These findings identify the main research themes in EEG and MCI and suggest promising avenues for future research in this field.

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

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

Association of Posttraumatic Epilepsy With Long-term Functional Outcomes in Individuals With Severe Traumatic Brain Injury

BACKGROUND AND OBJECTIVE

Nearly one-third of patients with severe traumatic brain injury (TBI) develop posttraumatic epilepsy (PTE). The relationship between PTE and long-term outcomes is unknown. We tested whether, after controlling for injury severity and age, PTE is associated with worse functional outcomes after severe TBI.

METHODS

We performed a retrospective analysis of a prospective database of patients with severe TBI treated from 2002 through 2018 at a single level 1 trauma center. Glasgow Outcome Scale (GOS) was collected at 3, 6, 12, and 24 months postinjury. We used repeated-measures logistic regression predicting GOS, dichotomized as favorable (GOS 4-5) and unfavorable (GOS 1-3), and a separate logistic model predicting mortality at 2 years. We used predictors as defined by the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) base model (i.e., age, pupil reactivity, and GCS motor score), PTE status, and time.

RESULTS

Of 392 patients who survived to discharge, 98 (25%) developed PTE. The proportion of patients with favorable outcomes at 3 months did not differ between those with and without PTE (23% [95% Confidence Interval [CI]: 15%-34%] vs 32% [95% CI: 27%-39%]; p = 0.11) but was significantly lower at 6 (33% [95% CI: 23%-44%] vs 46%; [95% CI: 39%-52%] p = 0.03), 12 (41% [95% CI: 30%-52%] vs 54% [95% CI: 47%-61%]; p = 0.03), and 24 months (40% [95% CI: 47%-61%] vs 55% [95% CI: 47%-63%]; p = 0.04). This was driven by higher rates of GOS 2 (vegetative) and 3 (severe disability) outcomes in the PTE group. By 2 years, the incidence of GOS 2 or 3 was double in the PTE group (46% [95% CI: 34%-59%]) compared with that in the non-PTE group (21% [95% CI: 16%-28%]; p < 0.001), while mortality was similar (14% [95% CI: 7%-25%] vs 23% [95% CI: 17%-30%]; p = 0.28). In multivariate analysis, patients with PTE had lower odds of favorable outcome (odds radio [OR] 0.1; 95% CI: 0.1-0.4; p < 0.001), but not mortality (OR 0.9; 95% CI: 0.1-1.9; p = 0.46).

DISCUSSION

Posttraumatic epilepsy is associated with impaired recovery from severe TBI and poor functional outcomes. Early screening and treatment of PTE may improve patient outcomes.

Association of Dementia Risk With Focal Epilepsy and Modifiable Cardiovascular Risk Factors

Importance

Epilepsy has been associated with cognitive impairment and potentially dementia in older individuals. However, the extent to which epilepsy may increase dementia risk, how this compares with other neurological conditions, and how modifiable cardiovascular risk factors may affect this risk remain unclear.

Objective

To compare the differential risks of subsequent dementia for focal epilepsy compared with stroke and migraine as well as healthy controls, stratified by cardiovascular risk.

Design, Setting, and Participants

This cross-sectional study is based on data from the UK Biobank, a population-based cohort of more than 500 000 participants aged 38 to 72 years who underwent physiological measurements and cognitive testing and provided biological samples at 1 of 22 centers across the United Kingdom. Participants were eligible for this study if they were without dementia at baseline and had clinical data pertaining to a history of focal epilepsy, stroke, or migraine. The baseline assessment was performed from 2006 to 2010, and participants were followed up until 2021.

Exposures

Mutually exclusive groups of participants with epilepsy, stroke, and migraine at baseline assessment and controls (who had none of these conditions). Individuals were divided into low, moderate, or high cardiovascular risk groups based on factors that included waist to hip ratio, history of hypertension, hypercholesterolemia, diabetes, and smoking pack-years.

Main Outcomes and Measures

Incident all-cause dementia; measures of executive function; and brain total hippocampal, gray matter, and white matter hyperintensity volumes.

Results

Of 495 149 participants (225 481 [45.5%] men; mean [SD] age, 57.5 [8.1] years), 3864 had a diagnosis of focal epilepsy only, 6397 had a history of stroke only, and 14 518 had migraine only. Executive function was comparable between participants with epilepsy and stroke and worse than the control and migraine group. Focal epilepsy was associated with a higher risk of developing dementia (hazard ratio [HR], 4.02; 95% CI, 3.45 to 4.68; P < .001), compared with stroke (HR, 2.56; 95% CI, 2.28 to 2.87; P < .001), or migraine (HR, 1.02; 95% CI, 0.85 to 1.21; P = .94). Participants with focal epilepsy and high cardiovascular risk were more than 13 times more likely to develop dementia (HR, 13.66; 95% CI, 10.61 to 17.60; P < .001) compared with controls with low cardiovascular risk. The imaging subsample included 42 353 participants. Focal epilepsy was associated with lower hippocampal volume (mean difference, -0.17; 95% CI, -0.02 to -0.32; t = -2.18; P = .03) and lower total gray matter volume (mean difference, -0.33; 95% CI, -0.18 to -0.48; t = -4.29; P < .001) compared with controls. There was no significant difference in white matter hyperintensity volume (mean difference, 0.10; 95% CI, -0.07 to 0.26; t = 1.14; P = .26).

Conclusions and Relevance

In this study, focal epilepsy was associated with a significant risk of developing dementia, to a greater extent than stroke, which was magnified substantially in individuals with high cardiovascular risk. Further findings suggest that targeting modifiable cardiovascular risk factors may be an effective intervention to reduce dementia risk in individuals with epilepsy.

Do Epilepsy Patients with Cognitive Impairment Have Alzheimer's Disease-like Brain Metabolism?

Although not classically considered together, there is emerging evidence that Alzheimer's disease (AD) and epilepsy share a number of features and that each disease predisposes patients to developing the other. Using machine learning, we have previously developed an automated fluorodeoxyglucose positron emission tomography (FDG-PET) reading program (i.e., MAD), and demonstrated good sensitivity (84%) and specificity (95%) for differentiating AD patients versus healthy controls. In this retrospective chart review study, we investigated if epilepsy patients with/without mild cognitive symptoms also show AD-like metabolic patterns determined by the MAD algorithm. Scans from a total of 20 patients with epilepsy were included in this study. Because AD diagnoses are made late in life, only patients aged ≥40 years were considered. For the cognitively impaired patients, four of six were identified as MAD+ (i.e., the FDG-PET image is classified as AD-like by the MAD algorithm), while none of the five cognitively normal patients was identified as MAD+ (χ² = 8.148, p = 0.017). These results potentially suggest the usability of FDG-PET in prognosticating later dementia development in non-demented epilepsy patients, especially when combined with machine learning algorithms. A longitudinal follow-up study is warranted to assess the effectiveness of this approach.

Prefrontal PV interneurons facilitate attention and are linked to attentional dysfunction in a mouse model of absence epilepsy

Absence seizures are characterized by brief periods of unconsciousness accompanied by lapses in motor function that can occur hundreds of times throughout the day. Outside of these frequent moments of unconsciousness, approximately a third of people living with the disorder experience treatment-resistant attention impairments. Convergent evidence suggests prefrontal cortex (PFC) dysfunction may underlie attention impairments in affected patients. To examine this, we use a combination of slice physiology, fiber photometry, electrocorticography (ECoG), optogenetics, and behavior in the Scn8a+/-mouse model of absence epilepsy. Attention function was measured using a novel visual attention task where a light cue that varied in duration predicted the location of a food reward. In Scn8a+/-mice, we find altered parvalbumin interneuron (PVIN) output in the medial PFC (mPFC) in vitro and PVIN hypoactivity along with reductions in gamma power during cue presentation in vivo. This was associated with poorer attention performance in Scn8a+/-mice that could be rescued by gamma-frequency optogenetic stimulation of PVINs. This highlights cue-related PVIN activity as an important mechanism for attention and suggests PVINs may represent a therapeutic target for cognitive comorbidities in absence epilepsy.

Breaking the CoDE of Cognitive Disorders in Epilepsy

[Box: see text]

Knowledge and misconceptions about epilepsy among people with epilepsy and their caregivers attending mental health clinics: A qualitative study in Taenia solium endemic pig-keeping communities in Tanzania

OBJECTIVE

Taenia solium (T. solium) neurocysticercosis (NCC) affects the central nervous system and is associated with 30% of acquired epilepsy in some endemic areas. Epilepsy is a stigmatizing disease in many societies and people with epilepsy (PWE) and their families experience discrimination. This study aimed to explore the knowledge, perceptions, and experiences of epilepsy among PWE and their caregivers attending mental health clinics.

METHODS

In T. solium endemic areas of Tanzania, PWE and their caregivers attending mental health clinics were identified and their informed consent was sought prior to study participation. In-depth interviews were conducted in Swahili language and analyzed thematically. The coding was undertaken by two independent researchers using NVivo (Version 12, QSR International).

RESULTS

Thirty-eight participants were interviewed. Three themes were identified during the analysis, namely, knowledge about epilepsy; perception of epilepsy; and experience with epilepsy among PWE and their caregivers. Participants commonly defined epilepsy as a "falling disease," perceived to be caused by witchcraft, and were unaware of the association between T. solium and epilepsy. Stigmatization of epilepsy was reported as a problem. Reported treatment patterns after the initial onset of epilepsy varied widely; however, patients usually began treatment with traditional healing methods, and only later opted for biomedical treatment. Patients had generally poor adherence to antiseizure medication, which could be caused by inadequate knowledge or irregular supply.

SIGNIFICANCE

Level of knowledge about epilepsy was low, and NCC was not mentioned as a cause of epilepsy among participants. Epilepsy was generally perceived to be the result of witchcraft, evil spirits, or curses. Health education is needed, including an explanation of the model of T. solium transmission and the insistence on hygiene measures. This could reduce the number of new infections with T. solium, improve access to prompt biomedical treatment, and improve the lives of PWE.

Which is more deleterious to cognitive performance? Interictal epileptiform discharges vs anti-seizure medication

Children with epilepsy commonly have comorbid neurocognitive impairments that severely affect their psychosocial well-being, education, and future career prospects. Although the provenance of these deficits is multifactorial, the effects of interictal epileptiform discharges (IEDs) and anti-seizure medications (ASMs) are thought to be particularly severe. Although certain ASMs can be leveraged to inhibit IED occurrence, it remains unclear whether epileptiform discharges or the medications themselves are most deleterious to cognition. To examine this question, 25 children undergoing invasive monitoring for refractory focal epilepsy performed one or more sessions of a cognitive flexibility task. Electrophysiological data were recorded to detect IEDs. Between repeated sessions, prescribed ASMs were either continued or titrated to <50% of the baseline dose. Hierarchical mixed-effects modeling assessed the relationship between task reaction time (RT), IED occurrence, ASM type, and dose while controlling for seizure frequency. Both presence (β ± SE = 49.91 ± 16.55 ms, p = .003) and number of IEDs (β ± SE = 49.84 ± 12.51 ms, p < .001) were associated with slowed task RT. Higher dose oxcarbazepine significantly reduced IED frequency (p = .009) and improved task performance (β ± SE = -107.43 ± 39.54 ms, p = .007). These results emphasize the neurocognitive consequences of IEDs independent of seizure effects. Furthermore, we demonstrate that inhibition of IEDs following treatment with select ASMs is associated with improved neurocognitive function.

Chemo-kindling in adult zebrafish alters spatial cognition but not social novelty recognition

In the past decades, zebrafish have gathered immense attention and importance in the field of neurological sciences. In the case of epilepsy, zebrafish have appeared as a promising acute animal model for the screening and identification of potential antiepileptic molecules. However, the necessity for establishing competent chronic models of epilepsy in zebrafish is apparent. In this regard, recently we developed a chemo-kindling zebrafish model with a better clinical resemblance. In the present study, an attempt to examine the effect of pentylenetetrazole (PTZ)-induced kindling on the cognitive functions of zebrafish was made. In brief, adult zebrafish were repetitively given a sub-effective concentration of PTZ, till the onset of clonic-tonic seizures, entitled as kindled. Thereafter, T-maze test and social recognition memory test were conducted to evaluate spatial memory and social novelty recognition memory of the fish. At the end, both the groups were sacrificed and the brains were isolated to estimate neurotransmitter and gene expression levels. It was observed that PTZ kindling induced spatial cognition deficits and lower social exploration in zebrafish. However, it didn't change the novelty recognition memory of kindled zebrafish. The results of genes and neurotransmitters estimations in the brain also supported the behavioural findings. The results concluded that PTZ kindling alters spatial cognitive functions in adult zebrafish without affecting the social novelty recognition memory.

Microglial activation and over pruning involved in developmental epilepsy

To understand the potential role of microglia in synaptic pruning following status epilepticus (SE), we examined the time course of expression of Iba-1, and immune and neuroinflammatory regulators, including CD86, CD206, and CX3CR1, and TLR4/NF-κB after SE induced by pilocarpine in rats. Behavioral tests, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, immunohistochemical staining, Western blotting, PCR, and fluorescence double staining assessments were performed. The expression of Iba-1 protein was lowest in the control group, and peaked after 2 days (p < 0.001). CD86 and CD206 mRNA levels increased gradually in the microglia of the epilepsy group after 12 hours, 1 day, 2 days, and 3 days; peak expression was on the second day. The expression of the chemokine receptor CX3CR1 in microglia increased to varying degrees after SE, and expression of the presynaptic protein synapsin decreased. The expression of TLR4/NF-κB in microglia positively correlated with Iba-1 protein expression. These findings indicate that the TLR4/NF-κB signaling pathway may be involved in the activation and polarization of microglia in epilepsy and in excess synaptic pruning, which could lead to an increase in brain injury.

Putative cause of seizure-induced cognitive alterations: The oscillatory reconfiguration of seizure network

Introduction

The dynamic reconfiguration of network oscillations is connected with cognitive processes. Changes in how neural networks and signaling pathways work are crucial to how epilepsy and related conditions develop. Specifically, there is evidence that prolonged or recurrent seizures may induce or exacerbate cognitive impairment. However, it still needs to be determined how the seizure brain configures its functional structure to shape the battle of strong local oscillations vs. slow global oscillations in the network to impair cognitive function.

Methods

In this paper, we aim to deduce the network mechanisms underlying seizure-induced cognitive impairment by comparing the evolution of strong local oscillations with slow global oscillations and their link to the resting state of healthy controls. Here, we construct a dynamically efficient network of pathological seizures by calculating the synchrony and directionality of information flow between nine patients' SEEG signals. Then, using a pattern-based method, we found hierarchical modules in the brain's functional network and measured the functional balance between the network's local strong and slow global oscillations.

Results and discussion

According to the findings, a tremendous rise in strong local oscillations during seizures and an increase in slow global oscillations after seizures corresponded to the initiation and recovery of cognitive impairment. Specifically, during the interictal period, local strong and slow global oscillations are in metastable balance, which is the same as a normal cognitive process and can be switched easily. During the pre-ictal period, the two show a bimodal pattern of separate peaks that cannot be easily switched, and some flexibility is lost. During the seizure period, a single-peak pattern with negative peaks is showcased, and the network eventually transitions to a very intense strong local oscillation state. These results shed light on the mechanism behind network oscillations in epilepsy-induced cognitive impairment. On the other hand, the differential (similarity) of oscillatory reorganization between the local (non) epileptogenic network and the global network may be an emergency protective mechanism of the brain, preventing the spread of pathological information flow to more healthy brain regions.

C-Met Receptors Deficiency Was Involved in Absence Seizures Development in WAG/Rij Rats

Background: A variety of receptors may be involved in the pathogenesis of absence seizures. The c-Met receptors have a critical role in modulating the GABAergic interneurons and creating a balance between excitatory and inhibitory neurotransmission, sensorimotor gating, and normal synaptic plasticity. Objectives: This study aimed to assess the changes of the c-Met receptor during the appearance of absence attacks in the experimental model of absence epilepsy. Methods: A total of 48 animals were divided into four groups of two- and six-month-old WAG/Rij and Wistar rats. Epileptic WAG/Rij rats showing SWP in electrocorticogram (ECoG) were included in the epileptic group. The two-month-old WAG/Rij rats as well as two- and six-month-old Wistar rats not exhibiting SWP in ECoG were selected as the non-epileptic. Gene (RT-PCR) and protein expression (western blotting) of c-Met receptors as well as c-Met protein distribution (immunohistochemistry) in the somatosensory cortex and hippocampus were assessed during seizure development of the absence attacks. Results: According to the study findings, a lower c-Met gene and protein expression, as well as a lower protein distribution, were observed in the hippocampus (P < 0.001, P < 0.05, and P < 0.001, respectively) and cortex (P < 0.01, P < 0.001 and P < 0.001, respectively) of the two-month-old WAG/Rij rats compared to the same-age Wistar rats. Moreover, the data revealed a reduction of hippocampal and cortical c-Met protein expression (P < 0.001, for both) in six-month-old WAG/Rij rats compared to two-month-old ones. Six-month-old WAG/Rij rats had a lower cortical c-Met gene (P < 0.05) and protein expression (P < 0.001) as well as lower hippocampal and cortical protein distribution (P < 0.05 and P < 0.001) than the same-age Wistar rats. Conclusions: In sum, the c-Met receptor was found to play a significant role in the development of absence epilepsy. This receptor, therefore, may have been considered as an effective goal for absence seizure inhibition.

Neuroprotective Effect of Celastrus Paniculatus Seed Extract on Epilepsy and Epilepsy-associated Cognitive Deficits

Introduction

Cognitive deficit is one of the common comorbidity accompanying epilepsy. The present study evaluated the effect of Celastrus paniculatus seed extract on seizure severity and cognitive deficit following the pentylenetetrazole (PTZ)-induced chemical kindling model.

Methods

PTZ kindling model was developed by daily administration of the sub-convulsive dose of PTZ 30 mg/kg for four weeks. After four weeks of induction, the following treatment, namely sodium valproic acid (SVA) 200 mg/kg, C. paniculatus 500 mg\kg, pergolide 2 mg/kg, C. paniculatus (250 mg\kg)+ Pergolide (1 mg/kg), and C. paniculatus (250 mg\kg)+ SVA (100 mg/kg) were administered 30 minutes prior to PTZ (30 mg/kg) injection for a period of next 14 days. Neurobehavioral parameters, including superoxide dismutase (SOD), Catalase (CAT), glutathione (GSH), and dopamine levels were assessed and the Morris water maze test (MWM) and Grip strength test (GPS) were performed. Hematoxylin & Eosin (H&E) staining of hippocampal cornu ammonis (CA1), CA2, CA3, dentate gyrus (DG), and frontal cortex was performed.

Results

C. paniculatus (500 mg/kg) alone and in combination (C. paniculatus (250 mg\ kg)+ pergolide (1 mg/kg) and C. paniculatus (250 mg\kg)+ SVA (100 mg/kg)) significantly (P<0.05) reduced the seizure score, mean latency time, and distance traveled in the MWM. However, no significant effect was seen in GPS. Biochemical analysis showed elevated antioxidant markers, namely GSH, CAT, and SOD, and also elevated dopamine levels. C. paniculatus and its combination also significantly (P<0.05) protected against neuronal loss in the hippocampus and frontal cortex evidenced by H&E staining.

Conclusion

C. paniculatus alone and in combination with other agents may have the potential to treat epilepsy and associated cognitive deficits.

Epilepsy and Cognitive Impairment in Childhood and Adolescence: A Mini-Review

Managing epilepsy in people with an intellectual disability remains a therapeutic challenge and must take into account additional issues such as diagnostic difficulties and frequent drug resistance. Advances in genomic technologies improved our understanding of epilepsy and raised the possibility to develop patients-tailored treatments acting on the key molecular mechanisms involved in the development of the disease. In addition to conventional antiseizure medications (ASMs), ketogenic diet, hormone therapy and epilepsy surgery play an important role, especially in cases of drugresistance. This review aims to provide a comprehensive overview of the mainfactors influencing cognition in children and adolescents with epilepsy and the main therapeutic options available for the epilepsies associated with intellectual disability.

Temporal Encephalocele: A Treatable Etiology of Drug-Resistant Pediatric Temporal Lobe Epilepsy

BACKGROUND

Temporal lobe encephaloceles (TEs) are a rare cause of drug-resistant temporal lobe epilepsy (DR-TLE), with head trauma and obesity identified as risk factors in adults. This study evaluated the clinical characteristics of childhood-onset DR-TLE due to TE.

METHODS

This is a single-institution retrospective review of childhood-onset DR-TLE with radiographic TE identified between 2008 and 2020. The epilepsy history, brain imaging features, and surgical outcomes were collected.

RESULTS

Eleven children with DR-TLE due to TE were included (median age at epilepsy onset was 11 years, interquartile range 8.5 to 13.5 years). Median latency between epilepsy diagnosis and TE detection was 3 years (range of 0 to 13 years). None had history of head trauma. Body mass index greater than 85 percentile for age and sex was seen in 36% of the children. No patient had bilateral TE identified. TEs were diagnosed based on epilepsy surgery conference re-review of imaging in 36% of cases. All herniations were contained defects without osseous dehiscence. Regional fluorodeoxyglucose (FDG) hypometabolism ipsilateral to the encephalocele was seen in all children who had FDG-positron emission tomography (PET) of the brain. Of the children who had surgery, 70% were seizure free or had nondisabling seizures at last follow-up (mean follow-up 52 months).

CONCLUSIONS

TE is a surgically remediable etiology of DR-TLE in childhood. TEs are often overlooked at pediatric epilepsy diagnosis, calling for the need to increase awareness of this entity. FDG-PET temporal hypometabolism in children with presumed nonlesional DR-TLE should be carefully examined for occult TEs.

DIFFERENT METABOLIC AND CLINICAL PROFILES BETWEEN PATIENTS WITH PURE ALZHEIMER DEMENTIA AND EPILEPTIC ALZHEIMER DEMENTIA : A METABOLIC STUDY

Aim: To investigate the clinical characteristics and cerebral FDG PET metabolisms of dementia patients who also diagnosed with epilepsy and compare the differences between with the pure Alzheimer dementia patients. Methods: In this case-control study, a total of 14 patients; 7 patients with pure Alzheimer disease as a control group and 7 age and gender matched patients with Alzheimer disease and concomitant epilepsy as a study group were included. Detailed neurocognitive battery and brain fludeoxyglucose positron emission tomography (FDG PET-CT) were performed for all subjects. Results: In comparison of neurocognitive test scores, there was no significant difference between study and control groups. However, geriatric depression scale scores were significantly lower in study group than the controls (p= 0.026). In cerebral FDG-PET CT profiles of subjects we detected significantly lower metabolism in left and right cerebellum, left lentiform nucleus, right thalamus and vermis in the study group (p=0.008, p=0.023, p=0.003, p=0.002, p=0.002, respectively). In the right parietotemporal cortex and right and left associative visual cortex, we found higher metabolism in the study group than controls ( p=0.023, p=0.012, p=0.003, respectively). Conclusion: Epileptic patients with Alzheimer dementia may have distinct clinical and metabolic profile than pure Alzheimer disease patients. Even if there is no difference in the neurocognitive clinical scores of the patients, depression and related functional abnormalities may be a biomarker of epileptic AD.

The ability of executive functions to predict deterioration in social abstraction in adolescents with idiopathic generalized epilepsy

Background

Epilepsy is a prevalent disease worldwide. Executive functions and social cognition are essential in daily living functioning, academic performance, and social adjustment. This study attempts to investigate the executive functions and ability to abstract social concepts in adolescents who have idiopathic generalized epilepsy and assess if the deterioration in executive functions can predict deterioration in the ability to abstract social concepts. Sixty adolescents with idiopathic generalized epilepsy aged between 12 and 19 collected from the neurology outpatient clinic at Sohag University Hospital in Upper Egypt were compared with 60 age- and sex-matched healthy adolescents regarding performance on executive function tests and ability to abstract social concepts tests. We used the Tower test to assess planning, the design fluency test to assess cognitive flexibility, the verbal fluency test to assess verbal fluency, and the Stroop test (overlapping between colour and word test) to assess inhibition and ability to abstract the social concepts test, which is composed of verbal part and performance part.

Results

Adolescents who have idiopathic generalized epilepsy have worse executive function impairment in all executive functions than control adolescents. Adolescents with idiopathic epilepsy have significantly more impairment in the ability to abstract social concepts (verbal and performance) compared to control adolescents. There is a significant correlation between executive functions and the ability to abstract social concepts (verbal and performance) in epileptic and control adolescents. Impairment in some executive functions can predict impairment in the ability to abstract social concepts (verbal and performance) in epileptic and control adolescents. Executive function impairment is correlated with the duration of illness, frequency of seizures per year, time since last epileptic fit, and presence of interictal epileptic discharge in EEG in the patient group.

Conclusions

Executive functions and the ability to abstract social concepts are significantly impaired in adolescents who have idiopathic generalized epilepsy. Impairment in executive functions can predict impairment in the ability to abstract social concepts. There is a need to screen executive functions and social abilities of adolescents with epilepsy and programmes to enhance these abilities.

Factors associated with global cognitive impairment in epilepsy patients: a cross-sectional study in Mataram, Indonesia

BACKGROUND Cognitive impairment is a major complication of epilepsy. This study aimed to investigate the factors associated with the prevalence of cognitive impairment in patients with epilepsy in Mataram, Indonesia. METHODS This cross-sectional study involved 155 consecutive outpatients with epilepsy at Mataram General Hospital, Mutiara Sukma Mental Hospital, and Siti Hajar Hospital, Mataram, Indonesia between September 2017 and August 2020. Data on the patient’s demographic characteristics, epilepsy, treatment variables, and global cognitive status were collected. The association between the determinants of epilepsy-associated cognitive impairment and the prevalence of epilepsy-associated global cognitive impairment was analyzed using logistic regression. RESULTS The prevalence of epilepsy-associated global cognitive impairment was 83.9% and related to a low level of education (odds ratio [OR] = 5.24, 95% confidence interval [CI] = 1.93–14.20), early age at onset (OR = 7.85, 95% CI = 0.82–33.79), and long duration of epilepsy (OR = 8.47, 95% CI = 1.95–36.88). CONCLUSIONS A high prevalence of epilepsy-associated global cognitive impairment was observed in Mataram and was associated with a low level of education, early age at onset, and long duration of epilepsy.

Cognitive impairment in epilepsy patients and its correlations

OBJECTIVE

Epilepsy is a severe disease in which seizures play the leading role. Striking clinical manifestations of the attacks take most of the attention of healthcare professionals. Apart from epilepsy itself, it is well known that epilepsy patients may also have psychiatric comorbidities. These disorders, such as anxiety and depression, are mostly thought to be related to epileptic seizures or antiepileptic medications. In clinical practice, cognitive impairment is another disrupted area of interest in epileptic patients. Our study aimed to detect this deterioration and its correlations with mood disorders and epileptic disease features such as seizure frequency and illness duration.

MATERIALS AND METHODS

After obtaining verbal and written consent, we enrolled 52 epilepsy patients in our study. A short demographic form indicating their gender, epileptic disease features, and medication usage information was completed for each patient. The Quick Mild Cognitive Impairment Screen (QMCI) test, the Hamilton Anxiety Rating Scale (Ham-A), and the Hospital Anxiety and Depression Scale (HADS) were applied by an experienced psychologist. Abnormal brain magnetic resonance imaging findings (e.g., encephalomalacia, large arachnoid cysts, a considerable amount of white matter gliotic lesions, neoplastic or vascular space-occupying lesions, hippocampal malformations), vitamin and electrolyte imbalances, other chronic diseases as well as thyroid dysfunction were considered as exclusion criteria since they might interfere with cognition. We excluded abnormalities to this extent because we wanted to acquire a homogenous sampling population without structural disadvantages. Thus, we could be able to determine slight changes in cognition properly.

RESULTS

We found decreased cognitive scores directly proportional to lower education level, higher seizure frequency, longer disease duration, generalized tonic-clonic (GTC) type of seizure, and antiepileptic polytherapy. Also, complying with the literature, a high frequency of depression was found in our study group. Interestingly, decreased anxiety levels of the patients were statistically related to higher seizure frequency, which may indicate adaptive mechanisms to frequent seizures. Finally, a multivariate regression analysis revealed a significant negative impact of GTC type of seizure on cognition.

CONCLUSION

Epilepsy and epileptic seizures affect cognition negatively. Thus, newly diagnosed epilepsy patients should be assessed for cognitive status as soon as possible. This assessment will allow epileptologists to understand future deteriorations in their patients' cognition. In our study, it is shown that QMCI is an effective and practical way to assess the cognitive statuses of epilepsy patients.

Gut dysbiosis following organophosphate, diisopropylfluorophosphate (DFP), intoxication and saracatinib oral administration

Organophosphate nerve agents (OPNAs) act as irreversible inhibitors of acetylcholinesterase and can lead to cholinergic crisis including salivation, lacrimation, urination, defecation, gastrointestinal distress, respiratory distress, and seizures. Although the OPNAs have been studied in the past few decades, little is known about the impact on the gut microbiome which has become of increasing interest across fields. In this study, we challenged animals with the OPNA, diisopropylfluorophosphate (DFP, 4mg/kg, s.c.) followed immediately by 2mg/kg atropine sulfate (i.m.) and 25mg/kg 2-pralidoxime (i.m.) and 30 minutes later by 3mg/kg midazolam (i.m.). One hour after midazolam, animals were treated with a dosing regimen of saracatinib (SAR, 20mg/kg, oral), a src family kinase inhibitor, to mitigate DFP-induced neurotoxicity. We collected fecal samples 48 hours, 7 days, and 5 weeks post DFP intoxication. 16S rRNA genes (V4) were amplified to identify the bacterial composition. At 48 hours, a significant increase in the abundance of Proteobacteria and decrease in the abundance of Firmicutes were observed in DFP treated animals. At 7 days there was a significant reduction in Firmicutes and Actinobacteria, but a significant increase in Bacteroidetes in the DFP groups compared to controls. The taxonomic changes at 5 weeks were negligible. There was no impact of SAR administration on microbial composition. There was a significant DFP-induced reduction in alpha diversity at 48 hours but not at 7 days and 5 weeks. There appeared to be an impact of DFP on beta diversity at 48 hours and 7 days but not at 5 weeks. In conclusion, acute doses of DFP lead to short-term gut dysbiosis and SAR had no effect. Understanding the role of gut dysbiosis in long-term toxicity may reveal therapeutic targets.

Neuroprotective and anti-epileptic potentials of genus Artemisia L

The Genus Artemisia L. is one of the largest genera in the Asteraceae family growing wild over in Europe, North America, and Central Asia and has been widely used in folk medicine for the treatment of various ailments. Phytochemical and psychopharmacological studies indicated that the genus Artemisia extracts contain various antioxidant and anti-inflammatory compounds and possess antioxidant, anti-inflammatory, antimicrobial, antimalarial, and antitumor activity. Recently, increasing experimental studies demonstrated that many Artemisia extracts offer a great antiepileptic potential, which was attributed to their bioactive components via various mechanisms of action. However, detailed literature on the antiepileptic properties of the genus Artemisia and its mechanism of action is segregated. In this review, we tried to gather the detailed neuroprotective and antiepileptic properties of the genus Artemisia and its possible underlying mechanisms. In this respect, 63 articles were identified in the PubMed and Google scholars databases, from which 18 studies were examined based on the pharmacological use of the genus Artemisia species in epilepsy. The genus Artemisia extracts have been reported to possess antioxidant, anti-inflammatory, neurotransmitter-modulating, anti-apoptotic, anticonvulsant, and pro-cognitive properties by modulating oxidative stress caused by mitochondrial ROS production and an imbalance of antioxidant enzymes, by protecting mitochondrial membrane potential required for ATP production, by upregulating GABA-A receptor and nACh receptor activities, and by interfering with various anti-inflammatory and anti-apoptotic signaling pathways, such as mitochondrial apoptosis pathway, ERK/CREB/Bcl-2 pathway and Nrf2 pathway. This review provides detailed information about some species of the genus Artemisia as potential antiepileptic agents. Hence, we recommend further investigations on the purification and identification of the most biological effective compounds of Artemisia and the mechanisms of their action to cure epilepsy and other neurological diseases.

Alterations of Plasma Pro-Inflammatory Cytokine Levels in Children with Refractory Epilepsies

Paediatric epilepsy is a multifaceted neurological disorder with various aetiologies. Up to 30% of patients are considered drug-resistant. The background impact of interfering inflammatory and neuronal pathways has been closely linked to paediatric epilepsy. The characteristics of the inflamed state have been described not only in epilepsies, which are considered prototypes of an inflammatory pathophysiology, but also in patients with drug-resistant epilepsy, especially in epileptic encephalopathies. The imbalance of different cytokine levels was confirmed in several epileptic models. Chemokines are new targets for exploring neuroimmune communication in epileptogenesis, which control leukocyte migration and have a possible role in neuromodulation. Additionally, prostaglandin E2 (PGE2) is an important effector molecule for central neural inflammatory responses and may influence drug responsiveness. We measured the serum interictal quantitative levels of chemokines (CCL2, CCL4, CCL11) and PGE2 in correlation with the seizure frequency and severity in controlled and intractable childhood epilepsies. Our refractory seizure group demonstrated significantly increased concentrations of eotaxin (CCL11) compared to the controlled epilepsy group. The higher level of CCL11 was correlated with an increased seizure frequency, while the PGE2 levels were associated with the severity of seizure and epilepsy, supporting the findings that proinflammatory cytokines may contribute to epileptogenesis and possibly have a role in developing seizure resistance.

The Role of Aberrant Neural Oscillations in the Hippocampal-Medial Prefrontal Cortex Circuit in Neurodevelopmental and Neurological Disorders

The hippocampus (HPC) and medial prefrontal cortex (mPFC) have well-established roles in cognition, emotion, and sensory processing. In recent years, interests have shifted towards developing a deeper understanding of the mechanisms underlying interactions between the HPC and mPFC in achieving these functions. Considerable research supports the idea that synchronized activity between the HPC and the mPFC is a general mechanism by which brain functions are regulated. In this review, we summarize current knowledge on the hippocampal-medial prefrontal cortex (HPC-mPFC) circuit in normal brain function with a focus on oscillations and highlight several neurodevelopmental and neurological disorders associated with aberrant HPC-mPFC circuitry. We further discuss oscillatory dynamics across the HPC-mPFC circuit as potentially useful biomarkers to assess interventions for neurodevelopmental and neurological disorders. Finally, advancements in brain stimulation, gene therapy and pharmacotherapy are explored as promising therapies for disorders with aberrant HPC-mPFC circuit dynamics.

Disruption of layer-specific visual processing in a model of focal neocortical epilepsy

The epileptic brain is the result of a sequence of events transforming normal neuronal populations into hyperexcitable networks supporting recurrent seizure generation. These modifications are known to induce fundamental alterations of circuit function and, ultimately, of behavior. However, how hyperexcitability affects information processing in cortical sensory circuits is not yet fully understood. Here, we investigated interlaminar alterations in sensory processing of the visual cortex in a mouse model of focal epilepsy. We found three main circuit dynamics alterations in epileptic mice: (i) a spreading of visual contrast-driven gamma modulation across layers, (ii) an increase in firing rate that is layer-unspecific for excitatory units and localized in infragranular layers for inhibitory neurons, and (iii) a strong and contrast-dependent locking of firing units to network activity. Altogether, our data show that epileptic circuits display a functional disruption of layer-specific organization of visual sensory processing, which could account for visual dysfunction observed in epileptic subjects. Understanding these mechanisms paves the way to circuital therapeutic interventions for epilepsy.

Dynamic coupling between the central and autonomic cardiac nervous systems in patients with refractory epilepsy: A pilot study

The heart and brain are reciprocally interconnected and engage in two-way communication for homeostatic regulation. Epilepsy is considered a network disease that also affects the autonomic nervous system (ANS). The neurovisceral integration model (NVM) proposes that cardiac vagal tone, indexed by heart rate variability (HRV), can indicate the functional integrity of cognitive neural networks. ANS activity and the pattern of oscillatory EEG activity covary during the transition of arousal states and associations between cortical and autonomic activity are reflected by HRV. Cognitive dysfunction is one of the common comorbidities that occur in epilepsy, including memory, attention, and processing difficulties. Recent studies have shown evidence for the active involvement of alpha activity in cognitive processes through its active role in the control of neural excitability in the cortex through top-down modulation of cortical networks. In the present pilot study, we evaluated the association between resting EEG oscillatory behavior and ANS function in patients with refractory epilepsy. Our results show: (1) In patients with refractory epilepsy, there is a strong positive correlation between HRV and the power of cortical oscillatory cortical activity in all studied EEG bands (delta, theta, alpha, and beta) in all regions of interest in both hemispheres, the opposite pattern found in controls which had low or negative correlation between these variables; (2) higher heartbeat evoked potential amplitudes in patients with refractory epilepsy than in controls. Taken together, these results point to a significant alteration in heart-brain interaction in patients with refractory epilepsy.

Cognitive impairment in people with epilepsy: Montreal Cognitive Assessment (MoCA) as a screening tool

OBJECTIVES

Although cognitive impairment is common in people with epilepsy, it is often neglected in outpatient clinics. MoCA is a simple and reliable test, which was validated for the cognitive screening of Alzheimer's and vascular dementia. The aim of our study was to evaluate MoCA as a tool for a cognitive screening of people with epilepsy.

METHODS

Our study included 50 people with epilepsy and 46 healthy individuals. All participants took the Slovenian version of the MoCA. Mean age, education and MoCA scores were compared between the two groups.

RESULTS

There was no significant difference between people with epilepsy and the controls in age (47.6, SD 18.1 vs 50.9, SD 14.0 years) or education (12.8, SD 2.8 vs 13.4, SD 2.8 years). People with epilepsy had significantly lower total MoCA scores than did the controls (23.3, SD 4.5 vs 27.5, SD 1.9 points; p < 0.001).

CONCLUSIONS

People with epilepsy achieved a lower score in several cognitive domains compared to the control group. MoCA can be used as an appropriate screening tool for cognitive impairment in people with epilepsy in the outpatient clinic. For a more accurate evaluation, neuropsychological assessments should be used.

Sakuranetin exerts anticonvulsant effect in bicuculline-induced seizures

Epilepsy is a chronic neurological disorder characterized by an abnormal, spontaneous, and synchronized neuronal hyperactivity. Therapeutic approaches for controlling epileptic seizures are associated with pharmacoresistance and side effects burden. Previous studies reported that different natural products may have neuroprotector effects. Sakuranetin (SAK) is a flavanone with antiparasitic, anti-inflammatory, antimutagenic, antiallergic, and antioxidant activity. In the present work, the effect of SAK on seizures in a model of status epilepticus induced by bicuculline (BIC) in mice was evaluated. Male Swiss mice received an intracerebroventricular injection (i.c.v.) of SAK (1, 10, or 20 mg/kg-SAK1, SAK10, or SAK20). Firstly, animals were evaluated in the open field (OF; 20 min), afterwards in the elevated plus maze (EPM) test (5 min). Next, 30 min prior the administration of BIC (1 mg/kg), mice received an injection of SAK (1 or 10 mg/kg, i.c.v.) and were observed in the OF (20 min) for seizures assessment. After behavioral procedures, immunohistochemical analysis of c-Fos was performed. Our main results showed that the lowest doses of SAK (1 and 10 mg/kg) increased the total distance traveled in the OF, moreover protected against seizures and death on the BIC-induced seizures model. Furthermore, SAK treatment reduced neuronal activity on the dentate gyrus of the BIC-treated animals. Taken together, our results suggest an anticonvulsant effect of SAK, which could be used for the development of anticonvulsants based on natural products from herbal source.

Epilepsy-associated increase in gonadotropin-releasing hormone neuron firing in diestrous female mice is independent of chronic seizure burden severity

Reproductive endocrine disorders are common comorbidities of temporal lobe epilepsy (TLE). Our previous studies using the intrahippocampal kainic acid (IHKA) mouse model of TLE demonstrated that many females show prolonged estrous cycles and hypothalamic gonadotropin-releasing hormone (GnRH) neurons exhibit elevated firing during diestrus. However, it is unknown whether the degree of change in GnRH neuron activity is dependent on epilepsy severity. Here, we used 24/7 in vivo electroencephalography (EEG) and in vitro electrophysiological recordings in acute brain slices to assess GnRH neuron firing in relation to chronic seizure burden in diestrous female mice at two months after IHKA injection. We found that percentage of time in seizure activity in the 24 h prior to slice preparation is an accurate proxy of overall seizure burden. Firing rates of GnRH neurons from EEG-recorded IHKA mice were increased in comparison to controls, but no relationships were found between GnRH neuron firing and seizure burden measured in vivo. The independence of GnRH neuron firing rate in relation to seizure burden was unaffected by GnRH neuron soma location or estrous cycle length. Furthermore, GnRH neuron firing rates were not yet different from control values when measured 1 month after injection, when epileptogenesis is already complete in IHKA mice. These findings indicate that the severity of epilepsy and the degree of downstream disruption to GnRH neuron activity are independent, suggesting that susceptibility to reproductive endocrine comorbidities is driven by other risk factors.

Tauopathy and Epilepsy Comorbidities and Underlying Mechanisms

Tau is a microtubule-associated protein known to bind and promote assembly of microtubules in neurons under physiological conditions. However, under pathological conditions, aggregation of hyperphosphorylated tau causes neuronal toxicity, neurodegeneration, and resulting tauopathies like Alzheimer's disease (AD). Clinically, patients with tauopathies present with either dementia, movement disorders, or a combination of both. The deposition of hyperphosphorylated tau in the brain is also associated with epilepsy and network hyperexcitability in a variety of neurological diseases. Furthermore, pharmacological and genetic targeting of tau-based mechanisms can have anti-seizure effects. Suppressing tau phosphorylation decreases seizure activity in acquired epilepsy models while reducing or ablating tau attenuates network hyperexcitability in both Alzheimer's and epilepsy models. However, it remains unclear whether tauopathy and epilepsy comorbidities are mediated by convergent mechanisms occurring upstream of epileptogenesis and tau aggregation, by feedforward mechanisms between the two, or simply by coincident processes. In this review, we investigate the relationship between tauopathies and seizure disorders, including temporal lobe epilepsy (TLE), post-traumatic epilepsy (PTE), autism spectrum disorder (ASD), Dravet syndrome, Nodding syndrome, Niemann-Pick type C disease (NPC), Lafora disease, focal cortical dysplasia, and tuberous sclerosis complex. We also explore potential mechanisms implicating the role of tau kinases and phosphatases as well as the mammalian target of rapamycin (mTOR) in the promotion of co-pathology. Understanding the role of these co-pathologies could lead to new insights and therapies targeting both epileptogenic mechanisms and cognitive decline.