Immunology: Barrier to electrical storms

BBB proteomic analysis reveals that complex febrile seizures in infancy enhance susceptibility to epilepsy in adulthood through dysregulation of ECM-receptor interaction signaling pathway

BACKGROUND

Complex febrile seizures (CFS) have been associated with an increased risk of epilepsy in adulthood. However, the specific link between blood-brain barrier (BBB) and the predisposition to epilepsy in adults who experienced CFS during infancy remains unclear. The objective of this study was to investigate the alteration of BBB in adult mice who had experienced CFS during infancy, and to explore the mechanisms of increased susceptibility to epilepsy after CFS.

METHODS

The CFS pup model was induced using hot air, and the seizure susceptibility was examined using low-dose pentylenetetrazole (PTZ) after 8 W. The brain microvessels representing BBB function were isolated and their protein expression changes were analyzed using data-independent acquisition (DIA) proteomic techniques. Subsequently, the bioinformatic analyses were performed using ClusterProfiler, STRING, Gene Set Enrichment Analysis (GSEA), etc. The enriched pathways, changes in the expression of BBB-related proteins, and alterations in metabolites including certain neurotransmitters were subsequently validated by Western Blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and mass spectrometric imaging (MSI). In addition, we selected the MMP inhibitor Incyclinide to verify that dysregulation of the ECM-receptor interaction signaling pathway increases epilepsy susceptibility in adult mice.

RESULTS

Mice that experienced CFS in infancy show increased susceptibility to epilepsy in adulthood, and BBB proteomic profile was significantly altered in the CFS mice. The network analysis suggests that dysregulation of the extracellular matrix (ECM)-receptor interaction pathway is a key mechanism. Moreover, MSI analysis uncovered notable changes in differential metabolites, including amino acids and nucleotide-derived neurotransmitters associated with the function of BBB maintaining neuronal homeostasis. Subsequent validation experiments showed that dysregulation of the ECM-receptor interaction signaling pathway exacerbated epilepsy susceptibility in adult mice.

CONCLUSION

Our research represents the pioneering demonstration of the modified BBB proteomics associated with epilepsy susceptibility in adult mice previously exposed to CFS in infancy. Notably, the increased susceptibility is attributed to the dysregulation of the ECM-receptor interaction pathway. These findings may help to elucidate the role of BBB alterations in the progression of epilepsy susceptibility, and provide new orientations for subsequent prevention and treatment of epilepsy.

Ictal vomiting as an unusual presentation of herpes simplex encephalitis - Pathophysiological and therapeutic perspectives

Introduction

Herpes Simplex Encephalitis (HSE) is a formidable neurological infection that is often challenging to diagnose owing to its diverse clinical manifestations. This case report details the clinical odyssey of a sixty-year-old female with diabetes, hypothyroidism, and hypertension, who presented with fever, vomiting, and evolving neurological symptoms.

Case Presentation

The patient's initial admission failed to yield a diagnosis, and her condition worsened, marked by behavioral changes, cognitive decline, and focal seizures. Neuroimaging revealed characteristic findings, confirming non-hemorrhagic herpetic encephalitis. Despite antiviral and antiepileptic therapy, persistent vomiting prompted further investigations, uncovering infrequent right temporal sharp waves on EEG, leading to a diagnosis of "ictus emiticus."

Conclusion

This case of Herpes Simplex Encephalitis (HSE) underscores the diverse clinical spectrum and challenges in management. The patient's atypical presentation underscores the importance of considering HSE in patients with fever and unexplained persistent vomiting for early diagnosis and better prognosis.Diagnostic tools (neuroimaging, cerebrospinal fluid analysis, and electroencephalography) confirmed HSE involvement in the right temporal lobe, emphasizing the strong association between HSV encephalitis and seizures, which can be explained by various mechanisms.Timely antiviral therapy and tailored antiepileptic strategies led to gradual clinical improvement, showcasing the potential of valproate beyond antiepileptic use.This case prompts further exploration into HSE's pathophysiology and treatment. It emphasizes individualized patient care and vigilance for potential post-resolution sequelae, contributing to our evolving understanding of HSE.

Therapeutic hypothermia for stroke: Unique challenges at the bedside

Therapeutic hypothermia has shown promise as a means to improving neurological outcomes at several neurological conditions. At the clinical level, it has been shown to improve outcomes in comatose survivors of cardiac arrest and in neonatal hypoxic ischemic encephalopathy, but has yet to be convincingly demonstrated in stroke. While numerous preclinical studies have shown benefit in stroke models, translating this to the clinical level has proven challenging. Major obstacles include cooling patients with typical stroke who are awake and breathing spontaneously but often have significant comorbidities. Solutions around these problems include selective brain cooling and cooling to lesser depths or avoiding hyperthermia. This review will cover the mechanisms of protection by therapeutic hypothermia, as well as recent progress made in selective brain cooling and the neuroprotective effects of only slightly lowering brain temperature. Therapeutic hypothermia for stroke has been shown to be feasible, but has yet to be definitively proven effective. There is clearly much work to be undertaken in this area.

Seizures and epilepsy secondary to viral infection in the central nervous system

Viral infection in the central nervous system (CNS) is a common cause of seizures and epilepsy. Acute symptomatic seizures can occur in the context of almost all types of acute CNS viral infection. However, late unprovoked seizures and epilepsy may not be frequent after viral infection of the CNS. The incidence of seizures and epilepsy after CNS viral infection is mainly dependent on the brain region of infection. It remains to be determined whether treatment of CNS viral infection using antiepileptic drugs (AEDs) can prevent seizures and subsequent epilepsy in patients, particularly with regard to the timing, drug choice and dosage, and duration of AEDs. The postoperative outcome of seizures in patients with intractable epilepsy caused by viral encephalitis primarily depends on the epileptogenic zone. In addition, neuroinflammation is known to be widely involved in the generation of seizures during CNS viral infection, and the effects of anti-inflammatory therapies in preventing seizures and epilepsy secondary to CNS viral infection require further studies. In this review, we discuss the incidence, mechanisms, clinical management and prognosis of seizures and epilepsy secondary to CNS viral infection, and summarize common CNS viral infections that cause seizures and epilepsy.

Molecular Mechanism Involved in the Pathogenesis of Early-Onset Epileptic Encephalopathy

Recent studies have shown that neurologic inflammation may both precipitate and sustain seizures, suggesting that inflammation may be involved not only in epileptogenesis but also in determining the drug-resistant profile. Extensive literature data during these last years have identified a number of inflammatory markers involved in these processes of "neuroimmunoinflammation" in epilepsy, with key roles for pro-inflammatory cytokines such as: IL-6, IL-17 and IL-17 Receptor (IL-17R) axis, Tumor-Necrosis-Factor Alpha (TNF-α) and Transforming-Growth-Factor Beta (TGF-β), all responsible for the induction of processes of blood-brain barrier (BBB) disruption and inflammation of the Central Nervous System (CNS) itself. Nevertheless, many of these inflammatory biomarkers have also been implicated in the pathophysiologic process of other neurological diseases. Future studies will be needed to identify the disease-specific biomarkers in order to distinguish epilepsies from other neurological diseases, as well as recognize different epileptic semiology. In this context, biological markers of BBB disruption, as well as those reflecting its integrity, can be useful tools to determine the pathological process of a variety of neurological diseases. However; how these molecules may help in the diagnosis and prognostication of epileptic disorders remains yet to be determined. Herein, authors present an extensive literature review on the involvement of both, systemic and neuronal immune systems, in the early onset of epileptic encephalopathy.

Therapeutic Hypothermia and Neuroprotection in Acute Neurological Disease

Therapeutic hypothermia has consistently been shown to be a robust neuroprotectant in many labs studying different models of neurological disease. Although this therapy has shown great promise, there are still challenges at the clinical level that limit the ability to apply this routinely to each pathological condition. In order to overcome issues involved in hypothermia therapy, understanding of this attractive therapy is needed. We review methodological concerns surrounding therapeutic hypothermia, introduce the current status of therapeutic cooling in various acute brain insults, and review the literature surrounding the many underlying molecular mechanisms of hypothermic neuroprotection. Because recent work has shown that body temperature can be safely lowered using pharmacological approaches, this method may be an especially attractive option for many clinical applications. Since hypothermia can affect multiple aspects of brain pathophysiology, therapeutic hypothermia could also be considered a neuroprotection model in basic research, which would be used to identify potential therapeutic targets. We discuss how research in this area carries the potential to improve outcome from various acute neurological disorders.

Unprovoked seizures in multiple sclerosis: Why are they rare?

INTRODUCTION

The frequency of seizures in patients with multiple sclerosis (MS) ranges from 1.5% to 7.8% and is considerably more common than chance events. The etiopathogenesis of seizures in MS is still poorly understood.

METHOD

A review of the literature on seizures and MS using PubMed.

RESULTS

Cortical gray matter involvement appears to be an all-too-common pathological finding in MS to play a primary role in the pathogenesis of seizures in MS patients. There is no clear relationship between seizures and the severity of MS. In approximately 10% of cases, a seizure is actually an initial neurological symptom of MS.

CONCLUSION

Searching for coherence in the occurrence of unprovoked seizures in MS directs attention to the dichotomy in MS pathology characterized by a complex intertwining of neuroinflammatory and neurodegenerative processes. The appearance (or nonappearance) of seizures in MS in relation to disease activity and disease progression indicates a distinct clinical phenotype of MS that opens up new perspectives in MS research.

Inflammation in Epileptic Encephalopathies

West syndrome (WS) is an infantile epileptic encephalopathy that manifests with infantile spasms (IS), hypsarrhythmia (in ~60% of infants), and poor neurodevelopmental outcomes. The etiologies of WS can be structural-metabolic pathologies (~60%), genetic (12%-15%), or of unknown origin. The current treatment options include hormonal treatment (adrenocorticotropic hormone and high-dose steroids) and the GABA aminotransferase inhibitor vigabatrin, while ketogenic diet can be given as add-on treatment in refractory IS. There is a need to identify new therapeutic targets and more effective treatments for WS. Theories about the role of inflammatory pathways in the pathogenesis and treatment of WS have emerged, being supported by both clinical and preclinical data from animal models of WS. Ongoing advances in genetics have revealed numerous genes involved in the pathogenesis of WS, including genes directly or indirectly involved in inflammation. Inflammatory pathways also interact with other signaling pathways implicated in WS, such as the neuroendocrine pathway. Furthermore, seizures may also activate proinflammatory pathways raising the possibility that inflammation can be a consequence of seizures and epileptogenic processes. With this targeted review, we plan to discuss the evidence pro and against the following key questions. Does activation of inflammatory pathways in the brain cause epilepsy in WS and does it contribute to the associated comorbidities and progression? Can activation of certain inflammatory pathways be a compensatory or protective event? Are there interactions between inflammation and the neuroendocrine system that contribute to the pathogenesis of WS? Does activation of brain inflammatory signaling pathways contribute to the transition of WS to Lennox-Gastaut syndrome? Are there any lead candidates or unexplored targets for future therapy development for WS targeting inflammation?

Mast cells in meningiomas and brain inflammation

Background

Research focus in neuro-oncology has shifted in the last decades towards the exploration of tumor infiltration by a variety of immune cells and their products. T cells, macrophages, B cells, and mast cells (MCs) have been identified.

Methods

A systematic review of the literature was conducted by searching PubMed, EMBASE, Google Scholar, and Turning Research into Practice (TRIP) for the presence of MCs in meningiomas using the terms meningioma, inflammation and mast cells.

Results

MCs have been detected in various tumors of the central nervous system (CNS), such as gliomas, including glioblastoma multiforme, hemangioblastomas, and meningiomas as well as metastatic brain tumors. MCs were present in as many as 90 % of all high-grade meningiomas mainly found in the perivascular areas of the tumor. A correlation between peritumoral edema and MCs was found.

Interpretation

Accumulation of MCs in meningiomas could contribute to the aggressiveness of tumors and to brain inflammation that may be involved in the pathogenesis of additional disorders.

Cerebrospinal Fluid Biomarkers of Japanese Encephalitis

Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Acute encephalitis syndrome (AES) is a group of central nervous system (CNS) disorders caused by a wide range of viruses, bacteria, fungi, chemicals and toxins. It is important to distinguish between various forms of infectious encephalitis with similar clinical manifestations in order to ensure specific and accurate diagnosis and development of subsequent therapeutic strategies. Cerebrospinal fluid (CSF) is in direct contact with the CNS and hence it is considered to be an excellent source for identifying biomarkers for various neurological disorders. With the recent advancement in proteomic methodologies, the field of biomarker research has received a remarkable boost.  The present study identifies potential biomarkers for JE using a proteomics based approach. The CSF proteomes from ten patients each with JE and Non-JE acute encephalitis were analyzed by 2D gel electrophoresis followed by mass spectrometry. Vitamin D-binding protein (DBP), fibrinogen gamma chain, fibrinogen beta chain, complement C4-B, complement C3 and cytoplasmic actin were found to be significantly elevated in case of JE indicating severe disruption of the blood brain barrier and DBP can be suggested to be an important diagnostic marker.

Epileptic seizures as a manifestation of cow's milk allergy: a studied relationship and description of our pediatric experience

Adverse reactions after ingestion of cow's milk proteins can occur at any age, from birth and even amongst exclusively breast-fed infants, although not all of these are hypersensitivity reactions. The most common presentations related to cow's milk protein allergy are skin reactions, failure to thrive, anaphylaxis as well as gastrointestinal and respiratory disorders. In addition, several cases of cow's milk protein allergy in the literature have documented neurological involvement, manifesting with convulsive seizures in children. This may be due to CNS spread of a peripheral inflammatory response. Furthermore, there is evidence that pro-inflammatory cytokines are responsible for disrupting the blood-brain barrier, causing focal CNS inflammation thereby triggering seizures, although further studies are needed to clarify the pathogenic relationship between atopy and its neurological manifestations. This review aims to analyze current published data on the link between cow's milk protein allergy and epileptic events, highlighting scientific evidence for any potential pathogenic mechanism and describing our clinical experience in pediatrics.

Targeting inflammation as a therapeutic strategy for drug-resistant epilepsies: an update of new immune-modulating approaches

An increasing body of literature data suggests that inflammation, and in particular neuroinflammation, is involved in the pathophysiology of particular forms of epilepsy and convulsive disorders. Animal models have been used to identify inflammatory triggers in epileptogenesis and inflammation has recently been shown to enhance seizures. For example, pharmacological blockade of the IL-1beta/IL-1 receptor type 1 axis during epileptogenesis has been demonstrated to provide neuroprotection in temporal lobe epilepsy. Furthermore, experimental models have suggested that neural damage and the onset of spontaneous recurrent seizures are modulated via complex interactions between innate and adaptive immunity. However, it has also been suggested that inflammation can occur as a result of epilepsy, since animal models have also shown that seizure activity can induce neuroinflammation, and that recurrent seizures maintain chronic inflammation, thereby perpetuating seizures. On the basis of these observations, it has been suggested that immune-mediated therapeutic strategies may be beneficial for treating some drug resistant epilepsies with an underlying demonstrable inflammatory process. Although the potential mechanisms of immunotherapeutic strategies in drug-resistant seizures have been extensively discussed, evidence on the efficacy of such therapy is limited. However, recent research efforts have been directed toward utilizing the potential therapeutic benefits of anti-inflammatory agents in neurological disease and these are now considered prime candidates in the ongoing search for novel anti-epileptic drugs. The objective of our review is to highlight the immunological features of the pathogenesis of seizures and to analyze possible immunotherapeutic approaches for drug resistant epilepsies that can alter the immune-mediated pathogenesis.

The immune modulating properties of the heat shock proteins after brain injury

Inflammation within the central nervous system often accompanies ischemia, trauma, infection, and other neuronal injuries. The immune system is now recognized to play a major role in neuronal cell death due to microglial activation, leukocyte recruitment, and cytokine secretion. The participation of heat shock proteins (Hsps) in the immune response following in brain injury can be seen as an attempt to correct the inflammatory condition. The Hsps comprise various families on the basis of molecular size. One of the most studied is Hsp70. Hsp70 is thought to act as a molecular chaperone that is present in almost intracellular compartments, and function by refolding misfolded or aggregated proteins. Hsps have recently been studied in inflammatory conditions. Hsp70 can both induce and arrest inflammatory reactions and lead to improved neurological outcome in experimental brain injury and ischemia. In this review, we will focus on underlying inflammatory mechanisms and Hsp70 in acute neurological injury.

Increased vascular permeability in the circumventricular organs of adult rat brain due to stimulation by extremely low frequency magnetic fields

It has been demonstrated that the exposure of biological systems to magnetic fields (MFs) can produce several beneficial effects: tissue recovery in chronic wounds, re-establishment of blood circulation after tissue ischemia or in necrotic tissues, improvement after epileptic episodes, angiogenesis, etc. In the current study, the effects of extremely low frequency (ELF) MF on the capillaries of some circumventricular organs (CVOs) are demonstrated; a vasodilator effect is reported as well as an increase in their permeability to non-liposoluble substances. For this study, 96 Wistar male rats (250 g body mass) were used and divided into three groups of 32 rats each: a control group (no treatment); a sham ELF-MF group; and an experimental group subjected to ELF-MF (120 Hz harmonic waves and 0.66 mT, root mean square) by the use of Helmholtz coils. All animals were administered colloidal carbon (CC) intravenously to study, through optical and transmission electron microscopy, the capillary permeability in CVOs and the blood-brain barrier (BBB) in brain areas. An increase in capillary permeability to CC was detected in the ELF-MF-exposed group as well as a significant increase in vascular area (capillary vasodilation); none of these effects were observed in individuals of the control and sham ELF-MF groups. It is important to investigate the mechanisms involved in the phenomena reported here in order to explain the effects of ELF-MF on brain vasculature.

Are you in or out? Leukocyte, ion, and neurotransmitter permeability across the epileptic blood-brain barrier

The credo that epileptic seizures can be initiated only by "epileptic" neurons has been recently challenged. The recognition of key astrocytic-neuronal communication, and the close interaction and crosstalk between astrocytes and brain endothelial cells, has shifted attention to the blood-brain barrier (BBB) and the "neurovascular unit." Therefore, the pursuit of mechanisms of seizure generation and epileptogenesis now includes investigations of cerebral blood flow and permeability of cerebral microvessels. For example, leukocyte adhesion molecules at the BBB have been proposed to play a role as an initiating factor for pilocarpine-induced status epilepticus, and a viral infection model with a strong BBB etiology has been used to study epileptogenesis. Finally, the fact that in nonepileptic subjects seizures can be triggered by BBB disruption, together with the antiseizure effects obtained by administration of potent antiinflammatory "BBB repair" drugs, has increased the interest in neuroinflammation; both circulating leukocytes and resident microglia have been studied in this context. The dual scope of this review is the following: (1) outline the proposed role of BBB damage and immune cell activation in seizure disorders; and (2) explain how increased cerebrovascular permeability causes neuronal misfiring. The temporal sequence linking seizures to peripheral inflammation and BBB dysfunction remains to be clarified. For example, it is still debated whether seizures cause systemic inflammation or vice versa. The topographic localization of fundamental triggers of epileptic seizures also remains controversial: Are immunologic mechanisms required for seizure generation brain-specific or is systemic activation of immunity sufficient to alter neuronal excitability? Finally, the causative role of "BBB leakage" remains a largely unresolved issue.

Fatal PML associated with efalizumab therapy: insights into integrin αLβ2 in JC virus control

OBJECTIVES

Progressive multifocal leukoencephalopathy (PML) has become much more common with monoclonal antibody treatment for multiple sclerosis and other immune-mediated disorders.

METHODS

We report 2 patients with severe psoriasis and fatal PML treated for ≥3 years with efalizumab, a neutralizing antibody to αLβ2-leukointegrin (LFA-1). In one patient, we conducted serial studies of peripheral blood and CSF including analyses of leukocyte phenotypes, migration ex vivo, and CDR3 spectratypes with controls coming from HIV-infected patients with PML. Extensive pathologic and histologic analysis was done on autopsy CNS tissue of both patients.

RESULTS

Both patients developed progressive cognitive and motor deficits, and JC virus was identified in CSF. Despite treatment including plasma exchange (PE) and signs of immune reconstitution, both died of PML 2 and 6 months after disease onset. Neuropathologic examination confirmed PML. Efalizumab treatment was associated with reduced transendothelial migration by peripheral T cells in vitro. As expression levels of LFA-1 on peripheral T cells gradually rose after PE, in vitro migration increased. Peripheral and CSF T-cell spectratyping showed CD8+ T-cell clonal expansion but blunted activation, which was restored after PE.

CONCLUSIONS

From these data we propose that inhibition of peripheral and intrathecal T-cell activation and suppression of CNS effector-phase migration both characterize efalizumab-associated PML. LFA-1 may be a crucial factor in homeostatic JC virus control.

Anti-inflammatory properties and pharmacological induction of Hsp70 after brain injury

The 70-kDa heat shock protein (Hsp70) is thought to protect the brain from a variety of insults. Although the mechanism has been largely limited to its chaperone functions, recent work indicates that Hsp70 also modulates inflammatory pathways. Brain injury and ischemia are associated with an immune response that is largely innate. Hsp70 appears to suppress this response and lead to improved neurological outcome. However, most of this work has relied on the use of genetic mutant models or Hsp70 overexpression using gene transfer or heat stress, thus limiting its translational utility. A few compounds have been studied by various disciplines which, through their ability to inhibit Hsp90, can cause induction of Hsp70. The investigation of Hsp70-inducing pharmacological compounds has obvious clinical implications in terms of potential therapies to mitigate neuroinflammation and lead to neuroprotection from stroke or traumatic brain injury. This review will focus on the inflammation modulating properties of Hsp70, and the current literature surrounding the pharmacological induction in acute neurological injury models with comments on potential applications at the clinical level.

Neuro-inflammation, blood-brain barrier, seizures and autism

Many children with Autism Spectrum Diseases (ASD) present with seizure activity, but the pathogenesis is not understood. Recent evidence indicates that neuro-inflammation could contribute to seizures. We hypothesize that brain mast cell activation due to allergic, environmental and/or stress triggers could lead to focal disruption of the blood-brain barrier and neuro-inflammation, thus contributing to the development of seizures. Treating neuro-inflammation may be useful when anti-seizure medications are ineffective.

Molecular cascades that mediate the influence of inflammation on epilepsy

Experimental evidence strongly indicates a significant role for inflammatory and immune mediators in initiation of seizures and epileptogenesis. Here we will summarize data supporting the involvement of IL-1β, TNF-α and toll-like receptor 4 in seizure generation and the process of epileptogenesis. The physiological homeostasis and control over brain immune response depends on the integrity of the blood-brain barrier, transforming growth factor (TGF)-β signaling and leukocyte migration. To what extent targeting the immune system is successful in preventing epileptogenesis, and which signaling pathway should be beleaguered is still under intensive research.

Distinct cerebrospinal fluid proteomes differentiate post-treatment lyme disease from chronic fatigue syndrome

Background

Neurologic Post Treatment Lyme disease (nPTLS) and Chronic Fatigue (CFS) are syndromes of unknown etiology. They share features of fatigue and cognitive dysfunction, making it difficult to differentiate them. Unresolved is whether nPTLS is a subset of CFS.

Methods and Principal Findings

Pooled cerebrospinal fluid (CSF) samples from nPTLS patients, CFS patients, and healthy volunteers were comprehensively analyzed using high-resolution mass spectrometry (MS), coupled with immunoaffinity depletion methods to reduce protein-masking by abundant proteins. Individual patient and healthy control CSF samples were analyzed directly employing a MS-based label-free quantitative proteomics approach. We found that both groups, and individuals within the groups, could be distinguished from each other and normals based on their specific CSF proteins (p<0.01). CFS (n = 43) had 2,783 non-redundant proteins, nPTLS (n = 25) contained 2,768 proteins, and healthy normals had 2,630 proteins. Preliminary pathway analysis demonstrated that the data could be useful for hypothesis generation on the pathogenetic mechanisms underlying these two related syndromes.

Conclusions

nPTLS and CFS have distinguishing CSF protein complements. Each condition has a number of CSF proteins that can be useful in providing candidates for future validation studies and insights on the respective mechanisms of pathogenesis. Distinguishing nPTLS and CFS permits more focused study of each condition, and can lead to novel diagnostics and therapeutic interventions.

Treatment of refractory epilepsy with natalizumab in a patient with multiple sclerosis. Case report

BACKGROUND

Multiple sclerosis (MS) is considered an autoimmune disease of the central nervous system and therapeutic inhibition of leukocyte migration with natalizumab, an anti-alpha4 integrin antibody, is highly effective in patients with MS. Recent studies performed in experimental animal models with relevance to human disease suggested a key role for blood-brain barrier damage and leukocyte trafficking mechanisms also in the pathogenesis of epilepsy. In addition, vascular alterations and increased leukocyte accumulation into the brain were recently documented in patients with refractory epilepsy independently on the disease etiology.

CASE REPORT

Here we describe the clinical course of a 24-year-old patient with MS in whom abrupt tonic-clonic generalized seizures manifested at disease onset. Although MS had a more favorable course, treatment with glatiramer acetate and antiepileptic drugs for 7 years had no control on seizure generation and the patient developed severe refractory epilepsy. Interestingly, generalized seizures preceded new MS relapses suggesting that seizure activity may contribute to MS worsening creating a positive feedback loop between the two disease conditions. Notably, treatment with natalizumab for 12 months improved MS condition and led to a dramatic reduction of seizures.

CONCLUSION

Our case report suggests that inhibition of leukocyte adhesion may represent a new potential therapeutic approach in epilepsy and complement the traditional therapy with anti-epileptic drugs.

Blood-brain barrier damage, but not parenchymal white blood cells, is a hallmark of seizure activity

It has long been held that chronic seizures cause blood-brain barrier (BBB) damage. Recent studies have also demonstrated that BBB damage triggers seizures. We have used the BBB osmotic disruption procedure (BBBD) to examine the correlation between BBB opening, pattern of white blood cell (WBCs) entry into the brain and seizure occurrence. These findings were compared to results from resected epileptic brain tissue from temporal lobe epilepsy (TLE) patients. We confirmed that a successful BBB osmotic opening (BBBD) leads to the occurrence of acute epileptiform discharges. Electroencephalography (EEG) and time-joint frequency analysis reveal EEG slowing followed by an increase in the 10-20Hz frequency range. Using green fluorescent protein (GFP)-labeled WBCs (GFP-WBCs) suspended in Evans Blue we found that, at time of BBB-induced epileptiform discharges, WBCs populated the perivascular space of a leaky BBB. Similar results were obtained at time of pilocarpine seizure. No frank WBCs extravasation in the brain parenchyma was observed. In TLE brain specimens, CD45-positive leukocytes were detected only in the vascular and perivascular spaces while albumin and IgG extravasates were parenchymal. The pattern was similar to those observed in rats. Our data suggest that neither acute-induced nor chronic seizures correlate with WBC brain parenchymal migration while albumin and IgG brain leakage is a hallmark of acute and chronic seizures.

Establishing the proteome of normal human cerebrospinal fluid

Background

Knowledge of the entire protein content, the proteome, of normal human cerebrospinal fluid (CSF) would enable insights into neurologic and psychiatric disorders. Until now technologic hurdles and access to true normal samples hindered attaining this goal.

Methods and Principal Findings

We applied immunoaffinity separation and high sensitivity and resolution liquid chromatography-mass spectrometry to examine CSF from healthy normal individuals. 2630 proteins in CSF from normal subjects were identified, of which 56% were CSF-specific, not found in the much larger set of 3654 proteins we have identified in plasma. We also examined CSF from groups of subjects previously examined by others as surrogates for normals where neurologic symptoms warranted a lumbar puncture but where clinical laboratory were reported as normal. We found statistically significant differences between their CSF proteins and our non-neurological normals. We also examined CSF from 10 volunteer subjects who had lumbar punctures at least 4 weeks apart and found that there was little variability in CSF proteins in an individual as compared to subject to subject.

Conclusions

Our results represent the most comprehensive characterization of true normal CSF to date. This normal CSF proteome establishes a comparative standard and basis for investigations into a variety of diseases with neurological and psychiatric features.

The emerging role for chemokines in epilepsy

Epilepsy has been considered mainly a neuronal disease, without much attention to non-neuronal cells. In recent years growing evidence suggest that astrocytes, microglia, blood leukocytes and blood-brain barrier breakdown are involved in the pathogenesis of epilepsy. In particular, leukocyte-endothelium interactions and eventually subsequent leukocyte recruitment in the brain parenchyma seem to represent key players in the epileptogenic cascade. Chemokines are chemotactic factors controlling leukocyte migration under physiological and pathological conditions. In the light of recent advances in our understanding of the role of inflammation mechanisms in the pathogenesis of epilepsy, pro-inflammatory chemokines may play a critical role in epileptogenesis.

Microbial induction of vascular pathology in the CNS

The central nervous system (CNS) is a finely tuned organ that participates in nearly every aspect of our day-to-day function. Neurons lie at the core of this functional unit and maintain an active dialogue with one another as well as their fellow CNS residents (e.g. astrocytes, oligodendrocytes, microglia). Because of this complex dialogue, it is essential that the CNS milieu be tightly regulated in order to permit uninterrupted and efficient neural chemistry. This is accomplished in part by anatomical barriers that segregate vascular components from the cerebral spinal fluid (CSF) and brain parenchyma. These barriers impede entry of noxious materials and enable the CNS to maintain requisite protein and ionic balances for constant electrochemical signaling. Under homeostatic conditions, the CNS is protected by the presence of specialized endothelium/epithelium, the blood brain barrier (BBB), and the blood-CSF barrier. However, following CNS infection these protective barriers can be comprised, sometimes resulting in severe neurological complications triggered by an imbalance or blockage of neural chemistry. In some instances, these disruptions are severe enough to be fatal. This review focuses on a selection of microbes (both viruses and parasites) that compromise vascular barriers and induce neurological complications upon gaining access to the CNS. Emphasis is placed on CNS diseases that result from a pathogenic interplay between host immune defenses and the invading microbe.

Key factors in the discovery and development of new antiepileptic drugs

Since the early 1990s, many new antiepileptic drugs (AEDs) that offer appreciable advantages in terms of their favourable pharmacokinetics, improved tolerability and lower potential for drug-drug interactions have entered the market. However, despite the therapeutic arsenal of old and new AEDs, approximately 30% of patients with epilepsy still suffer from seizures. Thus, there remains a substantial need for the development of more efficacious AEDs for patients with refractory seizures. Here, we briefly review the emerging knowledge on the pathological basis of epilepsy and how it might best be used in the design of new therapeutics. We also discuss the current approach to AED discovery and highlight some of the unique features of newer models of pharmacoresistance and epileptogenesis that have emerged in recent years.