Effect of prednisolone in a kindling model of epileptic seizures in rats on cytokine and intestinal microbiota diversity.

Epilepsy is a neurological disease characterized by spontaneous and recurrent seizures. Epileptic seizures can be initiated and facilitated by inflammatory mechanisms. As the dysregulation of the immune system would be involved in epileptogenesis, it is suggested that anti-inflammatory medications could impact epileptic seizures. These medications could potentially have a side effect by altering the structure and composition of the intestinal microbiota. These changes can disrupt microbial homeostasis, leading to dysbiosis and potentially exacerbating intestinal inflammation. We hypothesize that prednisolone may affect the development of epileptic seizures, potentially influencing the diversity of the intestinal microbiota and the regulation of pro-inflammatory cytokines in intestinal tissue. This study aimed to evaluate the effects of prednisolone treatment on epileptic seizures and investigate the effect of this drug on the bacterial diversity of the intestinal microbiota and markers of inflammatory processes in intestinal tissue. We used Male Wistar rat littermates (n = 31, 90-day-old) divided into four groups: positive control treated with 2 mg/kg of diazepam (n = 6), negative control treated with 0.9 g% sodium chloride (n = 6), and the remaining two groups were subjected to treatment with prednisolone, with one receiving 1 mg/kg (n = 9) and the other 5 mg/kg (n = 10). All administrations were performed intraperitoneally (i.p.) over 14 days. To induce the chronic model of epileptic seizures, we administered pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. Seizure latency (n = 6 - 10) and TNF-α and IL-1ß concentrations from intestinal samples were measured by ELISA (n = 6 per group), and intestinal microbiota was evaluated with intergenic ribosomal RNA (rRNA) spacer (RISA) analysis (n = 6 per group). The prednisolone treatment demonstrated an increase in the latency time of epileptic seizures and TNF-α and IL-1ß concentrations compared to controls. There was no statistically significant difference in intestinal microbiota diversity between the different treatments. However, there was a strong positive correlation between microbial diversity and TNF-α and IL-1ß concentrations. The administration of prednisolone yields comparable results to diazepam on increasing latency between seizures, exhibiting promise for its use in clinical studies. Although there were no changes in intestinal microbial diversity, the increase in the TNF-α and IL-1ß cytokines in intestinal tissue may be linked to immune system signaling pathways involving the intestinal microbiota. Additional research is necessary to unravel the intricacies of these pathways and to understand their implications for clinical practice.

Using integrated meta-omics to appreciate the role of the gut microbiota in epilepsy.

The way the human microbiota may modulate neurological pathologies is a fascinating matter of research. Epilepsy is a common neurological disorder, which has been largely investigated in correlation with microbiota health and function. However, the mechanisms that regulate this apparent connection are scarcely defined, and extensive effort has been conducted to understand the role of microbiota in preventing and reducing epileptic seizures. Intestinal bacteria seem to modulate the seizure frequency mainly by releasing neurotransmitters and inflammatory mediators. In order to elucidate the complex microbial contribution to epilepsy pathophysiology, integrated meta-omics could be pivotal. In fact, the combination of two or more meta-omics approaches allows a multifactorial study of microbial activity within the frame of disease or drug treatments. In this review, we provide information depicting and supporting the use of multi-omics to study the microbiota-epilepsy connection. We described different meta-omics analyses (metagenomics, metatranscriptomics, metaproteomics and metabolomics), focusing on current technical challenges in stool collection procedures, sample extraction methods and data processing. We further discussed the current advantages and limitations of using the integrative approach of multi-omics in epilepsy investigations.

Gut microbiome effects on neuronal excitability & activity: Implications for epilepsy.

It is now well established that the bacterial population of the gastrointestinal system, known as the gut microbiome, is capable of influencing the brain and its dependent functions. Links have been demonstrated between the microbiome and a variety of normal and pathological neural functions, including epilepsy. Many of these microbiome-brain links involve the direct or indirect modulation of the excitability and activity of individual neurons by the gut microbiome. Such links may be particularly significant when it comes to microbiome modulation of epilepsy, often considered a disorder of neuronal excitability. In this review we consider the current evidence of a relationship between the gut microbiome and the excitability or activity of neurons in the context of epilepsy. The review focuses particularly on evidence of direct, causal microbiome effects on neuronal excitability or activity, but also considers demonstrations of microbiome to host interactions that are likely to have an indirect influence. While we identify a few common themes, it is apparent that deriving general mechanistic principles of microbiome influence on these parameters in epilepsy will require considerable further study to tease out the many interacting factors, systems, and conditions.

The gut microbiota as a biomarker in epilepsy.

Biomarkers are defined as objectively measurable variables of a biologic process, either physiologic or pathologic, that provide reliable information on the status of that specific process in a specific moment. Validated biomarkers in epilepsy research represent an urgent unmet need being essential to improve research quality; as an example, biomarkers in epileptogenesis identifying these subjects at risk to develop epilepsy after an initial insult definitively would lead to an improvement in clinical studies to find antiepileptogenic drugs. The gut microbiota (GM) has recently encountered the interest of neuroscience which confirmed its clear involvement in several neurological disorders. GM's role in epilepsy has only recently been studied, however, interesting results are already available. Besides the interest in GM as a suitable therapeutic target and a few preclinical and clinical studies indicating the potential antiseizure effects of GM manipulation, microbiota composition has been found altered in patients with epilepsy as well as some animal models. Only few studies have tried to analyse GM composition as a suitable biomarker and, despite very promising, several drawbacks limit our understanding. On the other hand, GM composition may be useful in discriminating drug-resistant from drug-responsive patients at any stage or patients at risk of developing epilepsy after an insult. The main limitation in the area is the lack of large studies in homogeneous patients and standardization is a must for a proper understanding. Finally, considering the number of variables coming both from epilepsy and GM, big data analysis as in the case of genetics should be considered.

Evidences for a Role of Gut Microbiota in Pathogenesis and Management of Epilepsy.

Epilepsy as a chronic neurological disorder is characterized by recurrent, unprovoked epileptic seizures. In about half of the people who suffer from epilepsy, the root cause of the disorder is unknown. In the other cases, different factors can cause the onset of epilepsy. In recent years, the role of gut microbiota has been recognized in many neurological disorders, including epilepsy. These data are based on studies of the gut microbiota-brain axis, a relationship starting by a dysbiosis followed by an alteration of brain functions. Interestingly, epileptic patients may show signs of dysbiosis, therefore the normalization of the gut microbiota may lead to improvement of epilepsy and to greater efficacy of anticonvulsant drugs. In this descriptive review, we analyze the evidences for the role of gut microbiota in epilepsy and hypothesize a mechanism of action of these microorganisms in the pathogenesis and treatment of the disease. Human studies revealed an increased prevalence of Firmicutes in patients with refractory epilepsy. Exposure to various compounds can change microbiota composition, decreasing or exacerbating epileptic seizures. These include antibiotics, epileptic drugs, probiotics and ketogenic diet. Finally, we hypothesize that physical activity may play a role in epilepsy through the modulation of the gut microbiota.

The effect of different dietary structure on gastrointestinal dysfunction in children with cerebral palsy and epilepsy based on gut microbiota.

BACKGROUND: Gastrointestinal (GI) difficulties are very common among children with cerebral palsy (CP) and comorbid epilepsy. GI function is influenced by dietary structure on gut microbiota. The aim of this study was to compare gut microbiota differences in two dietary groups of this population and examine whether such differences are related to GI dysfunction. METHODS: Forty children with CP and epilepsy were recruited from a social welfare center, including 23 consuming a fluid diet (liquid diet group) and 17 consuming a normal diet (general diet group). Bacterial DNA was extracted from feces, the V3-V4 region of the 16S rRNA gene was amplified from the DNA, and high-throughput sequencing of the amplified sequences was performed. Microbe prevalence levels were compared on multiple phylogenic levels. RESULTS: Gut microbial populations differed substantially between the liquid diet group and general diet group. The only two phyla that differed significantly between the two groups were Bacteroidetes (p = 0.034) and Actinobacteria (p = 0.013). Regarding representation of genera, Prevotella species were selectively predominant in the general diet group (25.849% vs. 3.612% in the liquid diet group, p < 0.001), while Bifidobacterium species were selectively predominant in the liquid diet group (24.929% vs. 12.947% in the general diet group, p = 0.013). The gut microbiota of children in the general diet group contained more butyric acid-producing microbiota which was also common in healthy people (e.g. Lachnoclostridium, Dorea, Ruminococcus, Faecalibacterium, Roseburia, and Coprococcus). The gut microbiota of children in liquid diet group however, were rich in symbiotic pathogenic bacteria (e.g. Collinsella, Alistipes, and Eggerthella). CONCLUSION: The gut microbiota of children with CP and epilepsy consuming a liquid diet had elevated levels of symbiotic pathogens and diminished intestinal barrier protection bacteria, relative to a general diet group. These differences in bacterial microbiota were associated with GI dysfunction symptoms.

The potential role of interventions impacting on gut-microbiota in epilepsy.

INTRODUCTION: The gut microbiota seems to be implicated in the functioning and development of basic physiological processes and might also influence central neural processes, through the microbiota-gut-brain (MGB) axis. Pre- and clinical studies support the role of the microbiome in seizure modulation and in the pathogenesis of epilepsy. Acting through different interventions (e.g. diet, supplementations, drugs) could perturb directly and indirectly the MGB axis. Investigating the effects of these interventions might possibly allow better understanding of epilepsy itself, identify biomarkers, or providing new therapeutic options. AREAS COVERED: PubMed and Google Scholar searches were used to compile a list of relevant publications until January 2020, using data from preclinical studies and clinical trials and gut microbiome/microbiota projects. Furthermore, we evaluate the impact of the antiepileptic drugs on gut microbiota and the influence of intestinal alterations on seizures occurrence. EXPERT OPINION: Investigating the MGB axis and the role of gut supplementation in epilepsy is challenging due to the numerous potential pathways and variables involved. Few studies have been performed so far and all have been limited making speculation still premature. Studies designed with the similar strictness of pharmaceutical drug development trials, performing taxa, and metabolomic analyses with standard methodologies are needed.

Emerging roles for the intestinal microbiome in epilepsy.

The gut microbiome is emerging as a key regulator of brain function and behavior and is associated with symptoms of several neurological disorders. There is emerging evidence that alterations in the gut microbiota are seen in epilepsy and in response to seizure interventions. In this review, we highlight recent studies reporting that individuals with refractory epilepsy exhibit altered composition of the gut microbiota. We further discuss antibiotic treatment and infection as microbiome-related factors that influence seizure susceptibility in humans and animal models. In addition, we evaluate how the microbiome may mediate effects of the ketogenic diet, probiotic treatment, and anti-epileptic drugs on reducing both seizure frequency and severity. Finally, we assess the open questions in interrogating roles for the microbiome in epilepsy and address the prospect that continued research may uncover fundamental insights for understanding risk factors for epilepsy, as well as novel approaches for treating refractory epilepsy.

The gut microbiome in epilepsy.

The close relationship between epilepsy and autoimmune diseases and the fact that the cause of epilepsy is idiopathic in 60% of cases suggest that intestinal microbiota may play a role in the etiology of epilepsy. In this study, we analyzed and compared the intestinal microbiota composition of patients with idiopathic focal epilepsy (n = 30) and healthy volunteer group (n = 10) by 16s ribosomal DNA sequencing. Proteobacteria phylum was found to be higher in patients with epilepsy (25.4%) than in healthy volunteers group (1.5%). The genera of Campylobacter, Delftia, Haemophilus, Lautropia, Neisseria among Proteobacteria phylum were found to be statistically significantly higher in patients with epilepsy than in healthy volunteers (p < 0.05). Fusobacteria phylum was detected in 10.6% of the patients with epilepsy but not in the healthy volunteer group. The genus of the Fusobacteria phylum was found as Leptotrichia and Fusobacterium. In our study, taxonomic drift and significant differences in the intestinal microbiota of patients with epilepsy according to healthy volunteer group showed that autoimmune mechanisms and inflammation may have a role in the etiology of epilepsy. Our data should be supported by other studies as to the role of the intestinal microbiome in the prevention and treatment of epilepsy.

Personalized Nutrition: Are We There Yet?

The human genome has been proposed to contribute to interpersonal variability in the way we respond to nutritional intake. However, personalized diets solely based on gene-nutrient interactions have not lived up to their expectations to date. Advances in microbiome research have indicated that a science-based generation of a personalized diet based on a combination of clinical and microbial features may constitute a promising new approach enabling accurate prediction of dietary responses. In addition, scientific advances in our understanding of defined dietary components and their effects on human physiology led to the incorporation and testing of defined diets as preventive and treatment approaches for diseases, such as epilepsy, ulcerative colitis, Crohn disease, and type 1 diabetes mellitus. Additionally, exciting new studies show that tailored diet regiments have the potential to modulate pharmaceutical treatment efficacy in cancer treatment. Overall, the true therapeutic potential of nutritional interventions is coming to light but is also facing substantial challenges in understanding mechanisms of activity, optimization of dietary interventions for specific human subpopulations, and elucidation of adverse effects potentially stemming from some dietary components in a number of individuals.

Can we 'seize' the gut microbiota to treat epilepsy?

The gut-microbiota, the complex intestinal microbial ecosystem essential to health, is an emerging concept in medicine. Several studies demonstrate a microbiota-gut-brain bidirectional connection via neural, endocrine, metabolic and immune pathways. Accordingly, the gut microbiota has a crucial role in modulating intestinal permeability, to alter local/peripheral immune responses and in production of essential metabolites and neurotransmitters. Its alterations may consequently influence all these pathways that contribute to neuronal hyper-excitability and mirrored neuroinflammation in epilepsy and similarly other neurological conditions. Indeed, pre- and clinical studies support the role of the microbiome in pathogenesis, seizure modulation and responses to treatment in epilepsy. Up to now, researchers have focussed attention above all on the brain to develop antiepileptic treatments, but considering the microbiome, could extend our possibilities for developing novel therapies in the future. We provide here a comprehensive overview of the available data on the potential role of gut microbiota in the physiopathology and therapy of epilepsy and the supposed underlying mechanisms.

A Brain-Heart Biomarker for Epileptogenesis.

Postinjury epilepsy is an potentially preventable sequela in as many as 20% of patients with brain insults. For these cases biomarkers of epileptogenesis are critical to facilitate identification of patients at high-risk of developing epilepsy and to introduce effective anti-epileptogenic interventions. Here, we demonstrate that delayed brain-heart coincidences serve as a reliable biomarker. In a murine model of post-infection acquired epilepsy, we used long-term simultaneous measurements of the brain activity via electroencephalography and autonomic cardiac activity via electrocardiography, in male mice, to quantitatively track brain-heart interactions during epileptogenesis. We find that abnormal cortical discharges precede abnormal fluctuations in the cardiac rhythm at the resolution of single beat-to-beat intervals. The delayed brain-heart coincidence is detectable as early as the onset of chronic measurements, 2-14 weeks before the first seizure, only in animals that become epileptic, and increases during epileptogenesis. Therefore, delayed brain-heart coincidence serves as a biomarker of epileptogenesis and could be used for phenotyping, diagnostic, and therapeutic purposes.SIGNIFICANCE STATEMENT No biomarker that readily predicts and tracks epileptogenesis currently exists for the wide range of human acquired epilepsies. Here, we used long-term measurements of brain and heart activity in a mouse model of post-infection acquired epilepsy to investigate the potential of brain-heart interaction as a biomarker of epileptogenesis. We found that delayed coincidences from brain to heart can clearly separate the mice that became epileptic from those that did not weeks before development of epilepsy. Our findings allow for phenotyping and tracking of epileptogenesis in this and likely other models of acquired epilepsy. Such capability is critical for efficient adjunctive treatment development and for tracking the efficacy of such treatments.

Infective Causes of Epilepsy.

A wide range of infections of the central nervous system are responsible for both acute seizures and epilepsy. The pathogenesis and clinical semiology of the seizure disorders vary widely between the infective pathogens. The exact mechanisms underlying this are poorly understood, but appear, at least in part, to relate to the pathogen; the degree of cortical involvement; delays in treatment; and the host inflammatory response. The treatment of infective causes of seizures involves both symptomatic treatment with antiepileptic drugs and direct treatment of the underlying condition. In many cases, early treatment of the infection may affect the prognosis of the epilepsy syndrome. The greatest burden of acute and long-term infection-related seizures occurs in resource-poor settings, where both clinical and research facilities are often lacking to manage such patients adequately. Nevertheless, education programs may go a long way toward addressing the stigma, leading to improved diagnosis, management, and ultimately to better quality of life.

Characteristics and prognosis of pulmonary infection in patients with neurologic disease and hypoproteinemia.

OBJECTIVE: To examine the characteristics and the prognostic influence of pulmonary infections in neurologic disease patients with mild-to-severe hypoproteinemia. METHODS: We used a retrospective survey method to analyze the characteristics and prognoses of 220 patients with hypoproteinemia complicated with pulmonary infection in the Internal Medicine-Neurology Intensive Care Unit at the First Affiliated Hospital of Chongqing Medical University from January 2010 to December 2013. The patients were divided into mild, moderate and severe hypoproteinemia groups according to their serum albumin levels. The analysis included patient age, sex, acute physiology and chronic health evaluation (APACHE II score), and characteristics of the pulmonary infection, nutritional support and prognosis, among others. RESULTS: Differences in the general information of the 220 cases of hypoalbuminemia patients complicated with varying degrees of pulmonary infection (APACHE II score, age, disease distribution) were statistically significant. The pulmonary infection onset time and pathogen susceptibility in the patients with mild-to-severe hypoalbuminemia were not significantly different. Pulmonary infection onset was more frequently observed within the first 3-11 days following admission in all groups. The nutritional support method did not significantly influence serum albumin protein levels. However, the neurological intensive care unit stay length, total hospitalization cost and disease distribution were significantly different among the patient groups. CONCLUSIONS: Patients with cerebrovascular disease, intracranial infections and epilepsy complicated with pulmonary infection represent the high-risk groups for hypoalbuminemia. The Acinetobacter baumannii complex represents the main group of pathogenic bacteria causing lung infections, and the high-risk period for lung infections is 3-11 days after the occurrence of hypoalbuminemia. Patients with severe hypoalbuminemia complicated with pulmonary infection have the worst prognoses.

Chronic neuroborreliosis by B. garinii: an unusual case presenting with epilepsy and multifocal brain MRI lesions.

Late/chronic Lyme neuroborreliosis (LNB) represents a challenging entity whose diagnosis requires a combination of clinical and laboratory findings, surrounded by much controversy. Here we describe a patient who had a peculiar form of late LNB with CNS lesions shown by magnetic resonance imaging (MRI), and epileptic seizures, etiologically diagnosed by conventional and molecular methods. The current case provides evidence that patients presenting with epileptic seizures and MRI-detected multifocal lesions, particularly when a facial palsy has also occurred, should raise the suspicion of LNB, as this diagnosis has important implications for treatment and prognosis.

Helicobacter pylori infection in patients with epilepsy.

BACKGROUND: The possible role of Helicobacter pylori (HP) infection in extra-intestinal diseases has been suggested. The main purpose of this study was to determine the frequency of infection with HP in two groups of patients with epilepsy: patients with idiopathic generalized epilepsy (IGE) and patients with temporal lobe epilepsy (TLE), compared to healthy controls. METHODS: In this cross-sectional study a random sample of adult patients above 18 years of age with a diagnosis of IGE or TLE were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, from January 2009 through June 2011. A group of healthy individuals were included as control group. For all patients and controls a urea breath test (UBT) was requested. RESULTS: Thirty-four patients with IGE, 28 patients with TLE and 33 individuals as control were recruited. Positive UBT was observed in 21 individuals (61.8%) with IGE, 50% (14 patients) of patients with TLE and 72.7% (24 individuals) in control group. The difference between patients with IGE and control group was not significant (P=0.3). The difference between patients with TLE and control group was not significant either (P=0.068). CONCLUSION: The rate of HP infection was not higher in patients with epilepsy compared to healthy individuals. At the moment, there is not enough epidemiological data to support the role of HP infection in patients with either IGE or TLE.

Mycoplasma pneumoniae-related postencephalitic epilepsy in children.

PURPOSE: Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis, but there are few reports about it and postencephalitic epilepsy. This study aimed to investigate clinical factors, electroencephalography, and neuroradiologic features of M. pneumoniae-related encephalitis in a series of children with postencephalitic epilepsy and to examine possible prognostic factors. METHODS: Cases of M. pneumoniae-related encephalitis between January 2001 and June 2010 were retrospectively reviewed. Systematic clinical data were evaluated. KEY FINDINGS: The 99 enrolled patients with M. pneumoniae-related encephalitis were all positive by serology and 47 (47.5%) of them developed postencephalitic epilepsy. During the acute phase, 53 patients (53.5%) had seizures, the most common type of which was primary focal with secondary generalized tonic-clonic seizure (39.6%). The most common initial electroencephalography was focal/diffuse cortical dysfunction (37.4%) and focal epileptiform discharge (26.4%). The time of follow-up ranged from 6-131 months. At the end of the study, 19 (40.4%) of the 47 children with postencephalitic epilepsy had intractable seizures. SIGNIFICANCE: Postencephalitic epilepsy is not a rare complication of M. pneumoniae-related encephalitis. Seizures in the acute phase and focal epileptiform discharges in initial electroencephalography are significant prognostic factors.

Infectious causes of seizures and epilepsy in the developing world.

Central nervous system (CNS) infections are the main cause of seizures and acquired epilepsy in the developing world. Geographical variations determine the common causes in a particular region. Acute seizures are common in severe meningitis, viral encephalitis, malaria, and neurocysticercosis, and in most cases are associated with increased mortality and morbidity, including subsequent epilepsy. Neuronal excitability secondary to proinflammatory signals induced by CNS infections are an important common mechanism for the generation of seizures, in addition to various other specific mechanisms. Newer insights into the neurobiology of these infections and the associated epilepsy could help in developing neuroprotective interventions. Management issues include prompt treatment of acute seizures and the underlying CNS infection, correction of associated predisposing factors, and decisions regarding the appropriate choice and duration of antiepileptic therapy. Strategies for the prevention of epilepsy in CNS infections such as early anti-infective and anti-inflammatory therapy need scientific exploration. Prevention of CNS infections is the only definitive way forward to reduce the burden of epilepsy in developing countries.