Increased IL-1beta production from dsRNA-stimulated leukocytes in febrile seizures

Increased production of inflammatory cytokines by circulating monocytes in mesial temporal lobe epilepsy: A possible role in drug resistance

We analyzed peripheral blood mononuclear cells (PBMCs) and serum inflammatory biomarkers in patients with mesial temporal lobe epilepsy (drug-resistant - DR, vs. drug-sensitive - DS). Patients with epilepsy showed higher levels of serum CCL2, CCL3, IL-8 and AOPP, and lower levels of FRAP and thiols compared to healthy controls (HC). Although none of the serum biomarkers distinguished DR from DS patients, when analysing intracellular cytokines after in vitro stimulation, DR patients presented higher percentages of IL-1β and IL-6 positive monocytes compared to DS patients and HC. Circulating innate immune cells might be implicated in DR epilepsy and constitute potential new targets for treatments.

Neutrophil-lymphocyte ratio, red cell distribution width and mean platelet volume as practical markers in febrile seizure classification

OBJECTIVE

To examine the neutrophil-lymphocyte ratio, red cell distribution width and mean platelet volume in patients with febrile seizure and to determine their role in febrile seizure classification.

METHODS

This was a retrospective hospital-based study conducted among patients aged 5 to 72 months admitted with febrile seizure. Children who had febrile seizures due to upper respiratory tract infection were included in the study. The children were divided into two groups: simple febrile seizures and complex febrile seizures. Patients with a history of febrile status epilepticus, previous convulsions, use of antiepileptic or other chronic drugs, foci of infection other than the upper respiratory tract infection, abnormal biochemical parameters, and chronic mental or physical disease were excluded from the study. Clinical and laboratory findings of the patients were obtained from digital medical records.

RESULTS

The records of 112 febrile seizure patients were reviewed, and 89 were grouped as simple and 23 as complex febrile seizures. Although there was no statistically significant difference between the two groups in terms of the mean red cell distribution width values (p=0.703), neutrophil-lymphocyte ratio and mean platelet volume were significantly higher in patients with complex febrile seizures (p=0.034, p=0.037; respectively).

CONCLUSIONS

This study showed that neutrophil-lymphocyte ratio and mean platelet volume could be practical and inexpensive clinical markers for febrile seizure classification. A similar result could not be reached for red cell distribution width in this study. These findings should be supported by multicenter studies with large samples.

Association of IL-1B rs16944 Polymorphism With Acute Encephalopathy With Biphasic Seizures and Late Reduced Diffusion Is Opposite to That of Febrile Seizures

Objective

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe neurologic complication of febrile infectious diseases in children. At the onset, AESD is clinically manifested as febrile status epilepticus. Subsequent damage to the cerebral cortex is ascribed to neurotoxicity. The incidence of AESD is remarkably high in Japan, suggesting the involvement of genetic factors. The expression of interleukin 1 beta (IL-1β), a member of the cytokine family involved in the inflammatory response, is reportedly associated with rs16944, a polymorphism in the upstream region of the IL-1B gene, being higher in TT genotype. Previous association studies of rs16944 with febrile seizures (FS) have demonstrated a significant excess in the TT vs. CC + CT genotype in the Asian population. Here, we conducted a case-control association study of rs16944 in AESD.

Methods

We genotyped rs16944 by Sanger sequencing on 283 patients with AESD. As controls, we used genotyping data of 104 Japanese individuals obtained from the 1,000 Genomes Project. Then, we performed a case-control association study using the chi-square test.

Results

The ratio of individuals with TT vs. those with CC+CT genotype was significantly lower in AESD than in the controls [p-value 0.021, Odds Ratio (OR) 0.52]. This finding was opposite to that of a previously reported FS.

Conclusion

The AESD has a genetic background distinct from FS and is not a severe type of FS.

Cytokine Pattern of Peripheral Blood Mononuclear Cells Isolated from Children Affected by Generalized Epilepsy Treated with Different Protein Fractions of Meat Sources

The objective of the present study was the evaluation of cytokine patterns in terms of TNF-α, IL-10, IL-6, and IL-1β secretion in peripheral blood mononuclear cell (PBMC) supernatants isolated from blood of children affected by generalized epilepsy and treated in vitro with myofibrillar, sarcoplasmic, and total protein fractions of meat and fish sources. Children with generalized epilepsy (EC group, n = 16) and children without any clinical signs of disease, representing a control group (CC group n = 16), were recruited at the Complex Structure of Neuropsychiatry Childhood-Adolescence of Policlinico Riuniti (Foggia, Italy). Myofibrillar (MYO), sarcoplasmic (SA), and total (TOT) protein fractions were obtained from longissimus thoracis muscle of beef (BF) and lamb (LA); from pectoralis muscle of chicken (CH); and from dorsal white muscle of sole (Solea solea, SO), European hake (Merluccius merluccius, EH), and sea bass fish (Dicentrarchus labrax, SB), respectively. PBMCs were isolated from peripheral blood of EC and CC groups, and an in vitro stimulation in the presence of 100 μg/mL for each protein fraction from different meat sources was performed. Data were classified according to three different levels of cytokines produced from the EC group relative to the CC group. TNF-α, IL-10, and IL-6 levels were not affected by different meat fractions and meat sources; on the contrary, IL-1β levels were found to be significantly affected by the tested proteins fractions, as well as different meat sources, in high-level cytokine group. On average, the protein fractions obtained from LB, BF, and CH meat sources showed a higher level of IL-1β than the protein fractions obtained from EH and SB fish samples. When all cytokine classes were analyzed, on average, a significant effect was observed for IL-10, IL-1β, and TNF-α. Data obtained in the present study evidence that the nutritional strategy based on protein from fish and meat sources may modulate the immunological cytokine pattern of infants with generalized epilepsy.

Neuroinflammation: A Signature or a Cause of Epilepsy?

Epilepsy can be both a primary pathology and a secondary effect of many neurological conditions. Many papers show that neuroinflammation is a product of epilepsy, and that in pathological conditions characterized by neuroinflammation, there is a higher probability to develop epilepsy. However, the bidirectional mechanism of the reciprocal interaction between epilepsy and neuroinflammation remains to be fully understood. Here, we attempt to explore and discuss the relationship between epilepsy and inflammation in some paradigmatic neurological and systemic disorders associated with epilepsy. In particular, we have chosen one representative form of epilepsy for each one of its actual known etiologies. A better understanding of the mechanistic link between neuroinflammation and epilepsy would be important to improve subject-based therapies, both for prophylaxis and for the treatment of epilepsy.

Association between indel polymorphism (rs145204276) in the promoter region of lncRNA GAS5 and the risk of febrile convulsion

BACKGROUND

This study aimed to explore the regulatory relationship between growth arrest special 5 (GAS5) and interleukin-1β (IL-1β) implicated in the development of febrile seizure (FS).

METHOD

The presence of FS and the genotype of GAS5 were used as two different indicators to divide the 50 newborn babies, recruited in this study, into different groups. The potential regulatory relationship among GAS5, miR-21, and IL-1β was identified by measuring their expression using quantitative reverse-transcription polymerase chain reaction and immunohistochemistry assays among different sample groups. Computational analyses and luciferase assays were also conducted to verify the interaction between GAS5, miR-21, and IL-1β.

RESULT

GAS5 and IL-1β expression was upregulated in cells collected from FS patients or genotyped as INS/DEL and DEL/DEL, whereas the expression of miR-21 was decreased in above samples, indicating a negative relationship between miR-21 and GAS5/IL-1β. Results of the computational analysis showed that miR-21 directly bound to and increased the expression of GAS5, whereas the expression of IL-1β was suppressed by miR-21. In the presence of GAS5, the expression of miR-21 was lowered, whereas the expression of IL-1β was increased.

CONCLUSION

The results obtained in this study supported the conclusion that GAS5 negatively regulated the expression of miR-21, which in turn negatively regulated the expression IL-1β. Therefore, the overexpression of GAS5 could decrease the magnitude of FS.

Reduced cerebrospinal fluid levels of interleukin-10 in children with febrile seizures

PURPOSE

The exact etiology of febrile seizures (FS) is still unclear. However, it is thought that cytokine network activation may have a causative role. Therefore, this study aimed to evaluate the levels of interleukin-12 (IL-12) as a proinflammatory cytokine, interleukin-10 (IL-10) as an anti-inflammatory cytokine, and interferon-β (IFN-β), a marker of toll-like receptor-3 activation as a host response to viruses. These cytokine levels were analyzed in the cerebrospinal fluid (CSF) of children after a FS.

METHODS

With the approval of the Human Research Ethics Committee, 76 patients with FS, who underwent lumbar puncture (LP) for the exclusion of central nervous system (CNS) infection, and who didn't have CSF pleocytosis, were included in the study. The control group consisted of 10 patients with similar ages, with an acute febrile illness and who required LP to exclude CNS infection. The analyses were made by the enzyme-linked immunoassay method.

RESULTS

Age, gender distribution and CSF IL-12 and IFN- β levels did not differ, but CSF IL-10 levels were significantly lower in the FS group as compared to the control group (0.78 ± 4.5 pg/ml, versus 27 ± 29 pg/ml, p < 0.0001).

CONCLUSION

The low-level of CSF IL-10, considering its anti-inflammatory properties, may play a role in the etiopathogenesis of FS.

The role of Mean Platelet Volume/platelet count Ratio and Neutrophil to Lymphocyte Ratio on the risk of Febrile Seizure

Systemic inflammatory response has been implicated as a contributor to the onset of febrile seizures (FS). The four novel indices of the inflammatory response such as, neutrophil-to-lymphocyte ratio (NLR), mean platelet volume (MPV), platelet count (PLT) ratio and red blood cell distribution width (RDW) have been investigated in FS susceptibility and FS types (simple febrile seizure and complex febrile seizure). However, the potential role of these inflammatory markers and MPV/PLT ratio (MPR) in Chinese children with FS has yet to be fully determined. This study investigated the relevance of NLR, MPV, PLT, MPR and RDW in febrile children with and without seizures. 249 children with FS and 249 age matched controls were included in this study. NLR and MPR were calculated from complete blood cell counts prior to therapy. Differences in age, gender and these inflammatory markers between the FS group and the control group were evaluated using the chi-square test, t-test or logistic regression analysis. Receiver Operating Characteristic (ROC) curve was used to determine the optimal cut-off value of NLR and MPR for FS risk. Interactions between NLR and MPR on the additive scale were calculated by using the relative excess risk due to interaction (RERI), the proportion attributable to interaction (AP), and the synergy index (S). It has been shown that the elevated NLR and MPR levels were associated with increased risk of FS. The optimal cut-off values of NLR and MPR for FS risk were 1.13 and 0.0335 with an area under the curve (AUC) of 0.768 and 0.689, respectively. Additionally, a significant synergistic interaction between NLR and MPR was found on an additive scale. The mean levels of MPV were lower and NLR levels were higher in complex febrile seizure (CFS) than simple febrile seizure (SFS), and the differences were statistically significant. ROC analysis showed that the optimal cut-off value for NLR was 2.549 with 65.9% sensitivity and 57.5% specificity. However, no statistically significant differences were found regarding average values of MPR and RDW between CFS and SFS. In conclusion, elevated NLR and MPR add evidence to the implication of white cells subsets in FS risk, and our results confirmed that NLR is an independent, albeit limited, predictor in differentiating between CFS and SFS. Moreover, NLR and MPR may have a synergistic effect that can influence the occurrence of FS.

Intranasally administered pitavastatin ameliorates pentylenetetrazol-induced neuroinflammation, oxidative stress and cognitive dysfunction

AIM

The present study aimed to evaluate the neuroprotective potential of intranasally administered pitavastatin in the PTZ-induced kindling model.

MATERIALS AND METHODS

Subconvulsant dose of PTZ (35 mg/kg, i.p) was administered on an alternate day until the development of kindling. Behavioural test, biochemical tests and inflammatory cytokines were estimated. Comparative molecular docking study of sodium valproate (VPA) and pitavastatin was performed to predict the binding affinity with GABA_A and GABA transaminase. Intranasally administered pitavastatin (0.5 mg/kg and 1 mg/kg) and VPA (200 mg/kg) were used to investigate its protective effect.

KEY FINDINGS

Comparative in-silico study showed docking score of -4.56 and -2.86 against GABA_A receptor whereas -5.56 and -1.86, against GABA transaminase. Root mean square deviation (RMSD) of 0.39A and 0.55A was found for pitavastatin and VPA, respectively. The present study showed the dose-dependent protective effect of intranasally administered pitavastatin and oral VPA against PTZ-induced seizure, cognitive impairment, oxidative stress, and neuroinflammation.

SIGNIFICANCE

Our findings suggest that the intranasally administered pitavastatin is potential therapeutic approach to managing PTZ-induced kindling and associated comorbid conditions via its antioxidant, anti-inflammatory, and anticonvulsant potential. Further, pitavastatin can modulate GABA_A receptor and GABA transaminase enzyme to ameliorate seizure. Meanwhile, more extensive studies are required to establish the molecular mechanism underlying the neuroprotective effect of pitavastatin.

Polymorphisms in the interleukin-1β (IL-1B) and interleukin-1α (IL-1A) genes on risk of febrile seizures: a meta-analysis

The aim of the current study was to clarify the role of four common genetic polymorphisms in the interleukin-1β (IL-1B) and interleukin-1α (IL-1A) genes on risk of febrile seizures (FS) by means of meta-analyses. We searched for studies published until February 2018 using ISI Web of Science, Pubmed, Wanfang, and Chinese National Knowledge Infrastructure databases. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using MetaAnalyst version Beta 3.13. Seventeen case-control studies were included for meta-analysis. For the IL-1B rs16944 polymorphism, the summary analysis of studies conducted among Caucasian populations showed a significant association in the CT+TT versus CC contrast (OR 1.434, 95% CI 1.153-1.785), while the pooled analysis for Asian populations yielded a significant estimate in the TT versus CC+CT comparison (OR 1.393, 95% CI 1.051-1.846). No association was observed between the IL-1B rs1143627, IL-1B rs1143634, and IL-1A rs1800587 polymorphisms and FS risk. Sensitivity analyses excluding studies showing deviation from Hardy-Weinberg equilibrium did not alter conclusions. The findings of our meta-analysis suggest that the IL-1B rs16944 polymorphism may be an important genetic determinant for FS in Caucasian and Asian populations.

Status Epilepticus as an Unusual Manifestation of Heat Stroke

Heat stroke (HS) is a medical emergency and life threatening condition, characterized by body temperature over 40°C. This can lead to dysfunction of multiple organs such as the heart, liver, kidneys, lungs, blood coagulation system, and central nervous system. Neurological complications include change in consciousness, cerebellar dysfunction, convulsions, aphasia, muscular weakness, and parkinsonism. Cerebellar syndrome is the most common neurological finding in HS. We report a case of HS presenting with status epilepticus, without any other neurological manifestations. A 42 year old man, previously diagnosed with bipolar disorder, was admitted to the emergency room with high fever and repetitive generalized tonic-clonic seizures. He had been found unconscious after 4 hours of heavy physical work under extremely hot weather conditions. He was diagnosed with HS accompanied by status epilepticus, and treated with emergency body cooling and antiepileptics. Five days after admission, he regained consciousness and the laboratory parameters that were initially abnormal returned to normal values. On day 14, he was discharged without any neurological complications.

Novel Inflammatory Neuropathology in Immature Brain: (1) Fetal Tuberous Sclerosis, (2) Febrile Seizures, (3) α-B-crystallin, and (4) Role of Astrocytes

Though the term "inflammation" is traditionally defined as proliferation or infiltration of lymphatic cells of the lymphatic immune system and macrophages or as immunoreactive proteins including cytokines, interleukins and major histocompatibility complexes, recently recognized reactions to tissue injury also are inflammation, often occurring in the central nervous system in conditions where they previously were not anticipated and where they may play a role in both pathogenesis and repair. We highlight 4 such novel inflammatory conditions revealed by neuropathologic studies: (1) inflammatory markers and cells in the brain of human fetuses with tuberous sclerosis complex and perhaps other disorders of the mechanistic target of rapamycin genetic or metabolic pathway, (2) inflammatory markers in the brain related to febrile seizures of infancy and early childhood, (3) heat-shock protein upregulation in glial cells and neurons at sites of chronic epileptic foci, and (4) the emerging role of astrocytes in the presence of and participation in inflammation. Novel evidence shows that cerebral inflammation plays a role in some genetic diseases as early as midgestation and thus is not always acquired postnatally or in adult life.

Early-life febrile seizures worsen adult phenotypes in Scn1a mutants

Mutations in the voltage-gated sodium channel (VGSC) gene SCN1A, encoding the Na_v1.1 channel, are responsible for a number of epilepsy disorders including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS). Patients with SCN1A mutations often experience prolonged early-life febrile seizures (FSs), raising the possibility that these events may influence epileptogenesis and lead to more severe adult phenotypes. To test this hypothesis, we subjected 21-23-day-old mice expressing the human SCN1A GEFS+ mutation R1648H to prolonged hyperthermia, and then examined seizure and behavioral phenotypes during adulthood. We found that early-life FSs resulted in lower latencies to induced seizures, increased severity of spontaneous seizures, hyperactivity, and impairments in social behavior and recognition memory during adulthood. Biophysical analysis of brain slice preparations revealed an increase in epileptiform activity in CA3 pyramidal neurons along with increased action potential firing, providing a mechanistic basis for the observed worsening of adult phenotypes. These findings demonstrate the long-term negative impact of early-life FSs on disease outcomes. This has important implications for the clinical management of this patient population and highlights the need for therapeutic interventions that could ameliorate disease progression.

Inflammatory mediators in human epilepsy: A systematic review and meta-analysis

BACKGROUND

Accumulating evidence suggests a role for inflammation in the pathophysiology of epilepsy.

METHODS

We performed a systematic review and meta-analysis of studies that investigated inflammatory mediators in human epilepsy. Studies reporting on inflammatory mediators in serum, cerebrospinal fluid or brain tissue of epilepsy patients were included. Studies comparing patients to controls were included in a meta-analysis.

RESULTS

66 articles reporting on 1934 patients were included. IL-1ra, IL-1β, IL-6, IL-10, IFN-γ and TNF-α were the most extensively investigated proteins. Elevated levels for IL-1ra, IL-1β, IL-6 and CXCL8/IL-8 were reported in several different epilepsy etiologies and media, while other proteins were specifically increased for one etiology. IL-1α, IL-7 and IL-13, as well as the chemokines CCL2-5, -19 and -22, were increased exclusively in brain tissue. In an aggregate meta-analysis, we found significantly different protein levels for serum IL-6, IL-17 and CSF IL-1β and IL-10.

CONCLUSION

Inflammatory pathways are involved in epilepsy. Future studies may further clarify their role, and prove potential of targeted anti-inflammatory treatment.

Evaluation of the bioactivity of influenza vaccine strains in vitro suggests that the introduction of new strains in the 2010 Southern Hemisphere trivalent influenza vaccine is associated with adverse events

In Australia, during the 2010 Southern Hemisphere (SH) influenza season, there was an unexpected increase in post-marketing adverse event reports of febrile seizures (FS) in children under 5 years of age shortly after vaccination with the CSL trivalent influenza vaccine (CSL 2010 SH TIV) compared to previous CSL TIVs and other licensed 2010 SH TIVs. The present study describes the outcomes of a series of in vitro experiments directed at elucidating the root cause. The scientific investigations found that a subset of paediatric donors displayed elevated cytokine/chemokine responses to the CSL 2010 SH TIV but not to previous CSL TIVs nor other 2010 SH TIVs. The induction of elevated cytokines/chemokines in paediatric whole blood correlated with elevated NF-κB activation in a HEK293 cell reporter assay. The data indicate that the introduction of the B/Brisbane/60/2008 strain within the CSL manufacturing process (such as occurred in the preceding 2009/10 NH season) appears to have raised the pyrogenic potential of the CSL 2009/10 NH TIV but that this was insufficient to elicit FS in children <5 years. The 2010 SH season coincided with the first introduction of the H1N1 A/California/07/2009 in combination with the B/Brisbane/60/2008 strain. Our data demonstrates that the introduction of the H1N1 A/California/07/2009 (and to a much lesser degree, H3N2 A/Wisconsin/15/2009) in combination with B/Brisbane/60/2008 (as expressed through the CSL method of manufacture) combined and likely compounded the bioactivity of the CSL 2010 SH TIV. This was associated with stronger immune responses, which in a proportion of children <5 years were associated with FS. The assays and systems developed during these investigations should greatly assist in determining the bioactivity of new influenza strains, and thus aid with the manufacture of CSL TIVs indicated for use in the paediatric population.

Risk of subsequent asthma in children with febrile seizures: a nationwide population-based retrospective cohort study

BACKGROUND

No study has reported a relationship between febrile seizures and asthma; thus, we examined the association between these two disorders.

METHODS

We identified 991 cases of children with febrile seizures as the case cohort, and the control group was matched according to age, sex, urbanization level, and their parents' occupation at a 1:4 ratio. We applied the Cox proportional hazards regression model to estimate the hazard ratios and 95% confidence intervals for asthma among the children with febrile seizures.

RESULTS

After 11 years of follow-up, the asthma incidence in the febrile seizure group was approximately 5% higher than that in the control group (log-rank test, P < 0.0001). The risk of asthma in the febrile seizure group was 1.41 times higher than that in the control group (95% confidence interval, 1.21-1.65; P < 0.001). Furthermore, the risk of asthma development increased (0.96 vs 3.62) in conjunction with the frequency of febrile seizure-related medical visits (one to two visits vs more than four visits; P < 0.0001).

CONCLUSION

Febrile seizures may be associated with an increase in the risk of future asthma occurrence in children. We observed a significantly higher cumulative incidence of asthma occurrence in children with more febrile seizure-related medical visits.

Gender difference in acquired seizure susceptibility in adult rats after early complex febrile seizures

Gender differences are involved in many neurological disorders including epilepsy. However, little is known about the effect of gender difference on the risk of epilepsy in adults with a specific early pathological state such as complex febrile seizures (FSs) in infancy. Here we used a well-established complex FS model in rats and showed that: (1) the susceptibility to seizures induced by hyperthermia, pentylenetetrazol (PTZ), and maximal electroshock (MES) was similar in male and female rat pups, while males were more susceptible to PTZ- and MES-induced seizures than age-matched females in normal adult rats; (2) adult rats with complex FSs in infancy acquired higher seizure susceptibility than normal rats; importantly, female FS rats were more susceptible to PTZ and MES than male FS rats; and (3) the protein expression of interleukin-1β, an inflammatory factor associated with seizure susceptibility, was higher in adult FS females than in males, which may reflect a gender-difference phenomenon of seizure susceptibility. Our results provide direct evidence that the acquired seizure susceptibility after complex FSs is gender-dependent.

Serum interleukin-1beta and tumor necrosis factor-alpha in febrile seizures: is there a link?

Purpose

Febrile seizures are induced by fever and are the most common type of seizures in children. Although numerous studies have been performed on febrile seizures, their pathophysiology remains unclear. Recent studies have shown that cytokines may play a role in the pathogenesis of febrile seizures. The present study was conducted to identify potential links between serum interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and febrile seizures.

Methods

Ninety-two patients with simple or complex febrile seizures (46 patients per seizure type), and 46 controls with comparable age, sex, and severity of temperature were enrolled.

Results

The median concentrations of serum IL-1β in the simple, complex febrile seizure, and control groups were 0.05, 0.1, and 0.67 pg/mL, respectively (P=0.001). Moreover, the median concentrations of TNF-α in the simple, complex febrile seizure, and control groups were 2.5, 1, and 61.5 pg/mL, respectively (P=0.001). Furthermore, there were significant differences between the case groups in serum IL-1β and TNF-α levels (P<0.05).

Conclusion

Unlike previous studies, our study does not support the hypothesis that increased IL-1β and TNF-α production is involved in the pathogenesis of febrile seizures.

IL-1β: an important cytokine associated with febrile seizures?

Febrile seizures (FSs) are the most common convulsions in childhood. Studies have demonstrated a significant relationship between a history of prolonged FSs during early childhood and temporal sclerosis, which is responsible for intractable mesial temporal lobe epilepsy. It has been shown that interleukin-1β (IL-1β) is intrinsically involved in the febrile response in children and in the generation of FSs. We summarize the gene polymorphisms, changes of IL-1β levels and the putative role of IL-1β in the generation of FSs. IL-1β could play a role either in enhancing or in reducing neural excitability. If the enhancing and reducing effects are balanced, an FS does not occur. When the enhancing effect plays the leading role, an FS is generated. A mild imbalance can cause simple FSs while a severe imbalance can cause complex FSs and febrile status epilepticus. Therefore, anti-IL-1β therapy may help to treat FSs.

Increased association between febrile convulsion and allergic rhinitis in children: a nationwide population-based retrospective cohort study

BACKGROUND AND OBJECTIVES

Febrile convulsions and allergic rhinitis are both common childhood disorders and both are considered as generally benign disorders. Yet, especially in the case of allergic rhinitis, adverse effects on school performance and limited socialization are found. The relationship between febrile convulsions and allergic rhinitis has not been previously reported; thus, this article seeks to explore the association between these two disorders by collecting data from the Taiwanese nationwide cohort database.

METHODS

A total of 1304 children with febrile convulsions were identified as the case cohort, and controls were matched based on age, sex, urbanization levels, and parents' occupation on a 1 to 4 ratio. Cox's proportional hazards regression model was used to estimate the hazard ratio and confidence interval of allergic rhinitis disorder among children with febrile convulsions.

RESULTS

During an average 6.7 years follow-up period, the incidence of allergic rhinitis in the febrile convulsions case group was higher (65.16 vs 51.45 per 1000 person-years). After 11 years of follow-up, the allergic rhinitis incidence in the febrile convulsion patients was approximate 4% higher than controls (log-rank test P < 0.0001). Risk of allergic rhinitis in the febrile convulsions group was found to be 1.21 times higher than in the control group (95% confidence interval, 1.08-1.36). This risk of allergic rhinitis development is further increased (0.94 vs 18.9) with frequency of febrile convulsions-related medical visits (one to three visits vs more than three visits, P < 0.0001).

CONCLUSION

Febrile convulsions may be associated with allergic rhinitis occurrence in children. Children with more than three febrile convulsion-related medical visits had a significantly higher cumulative incidence of allergic rhinitis. Both disorders have previously been reported to have similar cytokine profiles and specific viral infection association. More studies are required to explore a possible link between the two disorders.

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.

Interleukin-1β secretion in hippocampal sclerosis patients with mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a common medically intractable epilepsy syndrome. Although pathogenesis of HS still remains highly controversial, genetics may play a role as a predisposing factor. Previous evidence in a Japanese population revealed that the homozygotes for allele T at position -511 of the interleukin (IL)-1β gene promoter region (IL-1β-511 T/T) confers susceptibility to the development of HS. However, whether this polymorphism has an effect on IL-1β levels in MTLEHS patients was not demonstrated. This study aimed to analyze the distribution of this particular polymorphism in a group of Turkish HS patients and correlate the polymorphism with IL-1β secretion from the lymphocytes, thus revealing a functional role for IL-1β in the etiopathogenesis of HS. A single base pair polymorphism at position -511 in the promoter region of the IL-1β gene was analyzed. The spontaneous and 1 ng/mL lipopolysaccharidestimulated production of IL-1β by peripheral blood mononuclear cells after 4 and 24 h of incubation were measured by ELISA method. The heterozygous type (-511 C/T) was the most common genotype. There was no difference in frequency of allele -511 T between patients and controls. Analysis of IL-1β levels, genotype and allele distributions showed no significant difference among the groups (P>0.05). Nevertheless, it was seen that patients who carry a T allele at position -511 of the IL-1β gene had increased IL-1β levels. T-allele carriage may be important. Only IL-1β secretion from the lymphocytes has been assessed in this study. Considering the importance of IL-1β in the etiopathogenesis of HS, further studies are needed to evaluate locally produced IL-1β levels.

Modulation of Immunity and the Inflammatory Response: A New Target for Treating Drug-resistant Epilepsy

Until recently, epilepsy medical therapy is usually limited to anti-epileptic drugs (AEDs). However, approximately 1/3 of epilepsy patients, described as drug-resistant epilepsy (DRE) patients, still suffer from continuous frequent seizures despite receiving adequate AEDs treatment of sufficient duration. More recently, with the remarkable progress of immunology, immunity and inflammation are considered to be key elements of the pathobiology of epilepsy. Activation of inflammatory processes in brain tissue has been observed in both experimental seizure animal models and epilepsy patients. Anti-inflammatory and immunotherapies also showed significant anticonvulsant properties both in clinical and in experimental settings. The above emerging evidence indicates that modulation of immunity and inflammatory processes could serve as novel specific targets to achieve potential anticonvulsant effects for the patients with epilepsy, especially DRE. Herein we review the recent evidence supporting the role of inflammation in the development and perpetuation of seizures, and also discuss the recent achievements in modulation of inflammation and immunotherapy applied to the treatment of epilepsy. Apart from medical therapy, we also discuss the influences of surgery, ketogenic diet, and electroconvulsive therapy on immunity and inflammation in DRE patients. Taken together, a promising perspective is suggested for future immunomodulatory therapies in the treatment of patients with DRE.

Do gene polymorphism in IL-1β, TNF-α and IL-6 influence therapeutic response in patients with drug refractory epilepsy?

PURPOSE

Pro-inflammatory cytokines may play an important pathophysiological role in patients with epilepsy. To understand the role of genes encoding pro-inflammatory cytokines in epilepsy, this study aimed to evaluate the polymorphisms of the promoter regions of IL-1β-511C>T (rs16944), TNF-α-308G>A (rs1800629) and IL-6-174G>C (rs1800795) genes and to look into the interaction between these genes in influencing seizure susceptibility, seizure frequency and response to therapy.

METHODS

The comparative frequency of polymorphism was determined in rs16944, rs1800629 and rs1800795 using PCR-RFLP in a group of 120 persons with epilepsy (PWE) and 110 ethnically matched healthy subjects of comparable age and sex in the North Indian population.

RESULTS

Alleles and genotypes of rs16944, rs1800629 and rs1800795 were not found to influence the odds ratio of having susceptibility to epilepsy. Also gene-gene interaction of possible nine combinations of these genes did not show any positive association with epilepsy. The genotype and allelic frequency of rs1800795 showed a significant association (p<0.05) in seizure frequency (number of seizures/6-months) and drug refractory epilepsy. However, the genotype and allelic frequency of rs16944 and rs1800629 were not found to have such effect.

CONCLUSION

This study demonstrates that the rs16944, rs1800629 and rs1800795 polymorphism does not act as a strong susceptibility factor for epilepsy in North Indian population. The genotypic association of rs1800795 with seizure frequency and drug-refractory epilepsy raises the issue that a specific set of polymorphic genes can influence seizures and therapeutic response in epilepsy.

Atypical febrile seizures, mesial temporal lobe epilepsy, and dual pathology

Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE.

Interleukin-6 gene polymorphism in febrile seizures

Febrile seizures comprise a common type of pediatric convulsion. Inflammation and genetics may be involved in their pathogenesis. Regarding the role of cytokines (especially interleukin-6) in febrile responses, we performed a case control study of interleukin-6 gene (-174, -572, and -597) single-nucleotide polymorphisms to learn if correlations existed between these particular polymorphisms and febrile seizures. We isolated the genomic DNA of 92 children with febrile seizures and 98 healthy control subjects. We genotyped individuals for their polymorphisms, using polymerase chain reaction-restriction fragment length polymorphism. In our study, the frequencies of -174 G alleles and of the -174 and -572 GG genotypes were observed to be significantly higher in patients than in control subjects. The -174 GG genotype frequency was significantly higher in children with a family history of febrile seizures.

Epilepsy and brain inflammation

During the last decade, experimental research has demonstrated a prominent role of glial cells, activated in brain by various injuries, in the mechanisms of seizure precipitation and recurrence. In particular, alterations in the phenotype and function of activated astrocytes and microglial cells have been described in experimental and human epileptic tissue, including modifications in potassium and water channels, alterations of glutamine/glutamate cycle, changes in glutamate receptor expression and transporters, release of neuromodulatory molecules (e.g. gliotransmitters, neurotrophic factors), and induction of molecules involved in inflammatory processes (e.g. cytokines, chemokines, prostaglandins, complement factors, cell adhesion molecules) (Seifert et al., 2006; Vezzani et al., 2011; Wetherington et al., 2008). In particular, brain injury or proconvulsant events can activate microglia and astrocytes to release a number of proinflammatory mediators, thus initiating a cascade of inflammatory processes in brain tissue. Proinflammatory molecules can alter neuronal excitability and affect the physiological functions of glia by paracrine or autocrine actions, thus perturbing the glioneuronal communications. In experimental models, these changes contribute to decreasing the threshold to seizures and may compromise neuronal survival (Riazi et al., 2010; Vezzani et al., 2008). In this context, understanding which are the soluble mediators and the molecular mechanisms crucially involved in glio-neuronal interactions is instrumental to shed light on how brain inflammation may contribute to neuronal hyperexcitability in epilepsy. This review will report the clinical observations in drug-resistant human epilepsies and the experimental findings in adult and immature rodents linking brain inflammation to the epileptic process in a causal and reciprocal manner. By confronting the clinical evidence with the experimental findings, we will discuss the role of specific soluble inflammatory mediators in the etiopathogenesis of seizures, reporting evidence for both their acute and long term effects on seizure threshold. The possible contribution of these mediators to co-morbidities often described in epilepsy patients will be also discussed. Finally, we will report on the anti-inflammatory treatments with anticonvulsant actions in experimental models highlighting possible therapeutic options for treating drug-resistant seizures and for prevention of epileptogenesis.

IL-1 receptor/Toll-like receptor signaling in infection, inflammation, stress and neurodegeneration couples hyperexcitability and seizures

Increasing evidence supports the involvement of immune and inflammatory processes in the etiopathogenesis of seizures. In particular, activation of innate immune mechanisms and the subsequent inflammatory responses, that are induced in the brain by infection, febrile seizures, neurotrauma, stroke are well documented conditions associated with acute symptomatic seizures and with a high risk of developing epilepsy. A decade ago, pharmacological experiments showed that elevated brain levels of the anti-inflammatory molecule IL-1 receptor antagonist reduced seizures in epilepsy models. This observation, together with the evidence of in situ induction of inflammatory mediators and their receptors in experimental and human epileptogenic brain tissue, established the proof-of-concept evidence that the activation of innate immunity and inflammation in the brain are intrinsic features of the pathologic hyperexcitable tissue. Recent breakthroughs in understanding the molecular organization of the innate immune system first in macrophages, then in the different cell types of the CNS, together with pharmacological and genetic studies in epilepsy models, showed that the activation of IL-1 receptor/Toll-like receptor (IL-1R/TLR) signaling significantly contributes to seizures. IL-1R/TLR mediated pro-excitatory actions are elicited in the brain either by mimicking bacterial or viral infections and inflammatory responses, or via the action of endogenous ligands. These ligands include proinflammatory cytokines, such as IL-1beta, or danger signals, such as HMGB1, released from activated or injured cells. The IL-1R/TLR signaling mediates rapid post-translational changes in voltage- and ligand-gated ion channels that increase excitability, and transcriptional changes in genes involved in neurotransmission and synaptic plasticity that contribute to lower seizure thresholds chronically. The anticonvulsant effects of inhibitors of the IL-1R/TLR signaling in various seizures models suggest that this system could be targeted to inhibit seizures in presently pharmaco-resistant epilepsies.

Brain inflammation as a biomarker in epilepsy

Experimental and clinical evidence have demonstrated the increased synthesis of specific inflammatory mediators, and the upregulation of their cognate receptors in the chronic epileptic brain, indicating that some proinflammatory pathways are activated in seizure foci. Inhibition of experimental seizures by pharmacological interference with specific proinflammatory signaling, together with evidence of changes in intrinsic susceptibility to seizures in transgenic mice with perturbed inflammatory pathways, was instrumental to establish the concept that brain inflammation has a role in the etiopathogenesis of seizures. Increasing evidence also highlights the possible involvement of inflammatory processes arising in the injured brain in the development of epilepsy (i.e., in epileptogenesis). Since brain inflammation in epilepsy is not a mere epiphenomenon of the pathology but is likely involved in the mechanisms underlying neuronal hyperexcitability, the onset of seizures and their recurrence, it might be considered as a biomarker of disease development and severity, and, as such, could be used for diagnostic, prognostic or therapeutic purposes, provided that adequate noninvasive methodologies are developed to detect and quantify brain inflammation in humans.

Diurnal variation in febrile convulsions

This study sought to determine diurnal variations in febrile convulsions, and to investigate whether such variations influenced the severity of febrile convulsions. The study involved 326 children, between ages 6 months and 6 years, with simple febrile convulsions. Data were collected systematically by interviewing witnesses within the week after febrile convulsions occurred. The frequency of febrile convulsions was approximately 5 times greater in the evening than in early morning. An adaptation curve revealed that the maximum occurrence of febrile convulsions was at 4:00 pm (4:00-4:59 pm), and the minimum, at 4:00 am (4:00-4:59 am), similar to the pattern of human body temperature. Temperature and seizure duration did not differ significantly between high-frequency and low-frequency zones (2:00-7:00 pm and 2:00-7:00 am, respectively) (high-frequency zone vs low-frequency zone, 39.20 degrees C (S.D., 0.68 degrees C) vs 39.22 degrees C (S.D., 0.64 degrees C) and 3.82 minutes (S.D., 5.27 minutes) vs 3.14 minutes (S.D., 3.19 minutes)). These results suggest that the circadian rhythm does not change seizure propensity, but its hourly occurrence is attributable to an elevation in the temperature set point in the 24-hour period. The prevention of recurrent febrile convulsions by rectal administration of anticonvulsants in high-frequency zones would be clinically helpful.

Febrile seizures: current views and investigations

Febrile seizures (FSs) are seizures that occur during fever, usually at the time of a cold or flu, and represent the most common cause of seizures in the pediatric population. Up to 5% of children between the ages of six months and five years-of-age will experience a FS. Clinically these seizures are categorized as benign events with little impact on the growth and development of the child. However, studies have linked the occurrence of FSs to an increased risk of developing adult epileptic disorders. There are many unanswered questions about FSs, such as the mechanism of their generation, the long-term effects of these seizures, and their role in epileptogenesis. Answers are beginning to emerge based on results from animal studies. This review summarizes the current literature on animal models of FSs, mechanisms underlying the seizures, and functional, structural, and molecular changes that may result from them.

Febrile seizures and temporal lobe epileptogenesis

Febrile seizures (FS) are a common neurological disorder that affects children. Simple FS are thought to be benign but experimental and clinical evidence support that the risk of developing epilepsy after FS increases if the FS are prolonged and the brain is abnormal. In addition, prolonged FS (PFS) have many deleterious long-term effects characterized mainly in the hippocampus but may involve the whole brain and that prompt abortive treatment of PFS may prevent some of the adverse effects. This review focuses on some of the key factors involved in the generation of FS, factors leading to PFS and potential mechanisms and functional correlates leading to temporal lobe epilepsy (TLE).

Febrile seizures: characterization of double-stranded RNA-induced gene expression

An association has long been suspected between febrile seizures and interleukin-1beta, the most potent endogenous pyrogen. Interleukin-1beta production increases after double-stranded RNA stimulation in leukocytes of febrile seizure patients. To elucidate the genetics of the immune response, the gene expression pattern after double-stranded RNA stimulation was investigated using DNA microarray. Compared with the control group, expression of the genes ACCN4 (sodium channel), KCNC3 (potassium channel), GABRE (gamma-aminobutyric acid receptor epsilon subunit), RIPK2 (receptor interacting protein kinase-2), TLR4 (toll-like receptor-4), IL26 (interleukin-26), and TNF (tumor necrosis factor), and CASP1 (caspase-1) was increased in the febrile seizure group (P < 0.01). Because RIPK2 and CASP1 are associated with interleukin-1beta production, increased expression might cause increased interleukin-1beta production in the febrile seizure patients. The induced expression of several ion channel genes by double-stranded RNA may affect neuronal excitability which leads to seizure susceptibility during infection.

The role of interleukin-1beta in febrile seizures

Febrile seizures (FS) occur in children as a result of fever. Despite their prevalence, the pathophysiology of FS has remained unclear. Recent evidence from clinical and experimental studies has highlighted a potential role of immune generated products in the genesis of FS. Of particular interest are the pro-inflammatory cytokine, interleukin-1beta (IL-1beta) and its naturally occurring antagonist, interleukin 1 receptor antagonist (IL-1ra). Using a novel animal model of FS, involving the generation of physiological fever, we investigated the role of the IL-1beta/IL-1ra system in the genesis of FS. We found that animals with FS had increased hippocampal and hypothalamic IL-1beta compared to equally treated animals without FS, which was first evident at onset of FS in the hippocampus. There were no differences in IL-1ra levels. ICV IL-1beta increased the number of animals with FS while IL-1ra had an opposite anti-convulsant effect. The data from these studies, in combination with recent results from other laboratories, have established a putative role for the IL-1beta/IL-1ra system in the genesis of FS.

Progress in searching for the febrile seizure susceptibility genes

Febrile seizures (FS) represent the most common form of childhood seizures. They affect 2-5% of infants in the Caucasian population and are even more common in the Japanese population, affecting 6-9% of infants. Some familial FS are associated with a wide variety of afebrile seizures. Generalized epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome with a spectrum of phenotypes including FS, atypical FS (FS+) and afebrile seizures. A significant genetic component exists for susceptibility to FS and GEFS+: extensive genetic studies have shown that at least nine loci are responsible for FS. Furthermore, mutations in the voltage-gated sodium channel subunit genes (SCN1A, SCN2A and SCN1B) and the GABA(A) receptor subunit genes (GABRG2 and GABRD) have been identified in GEFS+. However, the causative genes have not been identified in most patients with FS or GEFS+. Common forms of FS are genetically complex disorders believed to be influenced by variations in several susceptibility genes. Recently, several association studies on FS have been reported, but the results vary among different groups and no consistent or convincing FS susceptibility gene has emerged. Herein, we review the genetic data reported in FS, including the linkage analysis, association studies, and genetic abnormalities found in the FS-related disorders such as GEFS+ and severe myoclonic epilepsy in infancy.

Long-term behavioral outcome after early-life hyperthermia-induced seizures

Febrile seizures (FS) are among the most common types of seizures in the developing brain. It has been suggested that FS cause cognitive deficits that proceed into adulthood, but the information is conflicting. The aim of the present study was to determine whether experimental FS have long-term cognitive or behavioral deficits. FS were induced by hyperthermia (30 minutes, approximately 41 degrees C) in 10-day-old rat pups, and behavioral testing was performed. Hippocampus-dependent water maze learning, locomotor activity, and choice reaction time parameters (e.g., reaction time) were generally not affected by FS. However, more detailed analysis revealed that reaction times on the right side were slower than those on the left in controls, whereas this was not observed after FS. Early-life experimental FS did not cause overt cognitive and behavioral deficits, which is in line with previous work, but eliminated the lateralization effect in reaction time known to occur in normal controls, an effect that may be due to the combination of FS and kainic acid or to FS alone.

The role of interleukin-1 in seizures and epilepsy: a critical review

Interleukin-1 (IL-1) has a multitude of functions in the central nervous system. Some of them involve mechanisms that are related to epileptogenesis. The role of IL-1 in seizures and epilepsy has been investigated in both patients and animal models. This review aims to synthesize, based on the currently available literature, the consensus role of IL-1 in epilepsy. Three lines of evidence suggest a role for IL-1: brain tissue from epilepsy patients and brain tissue from animal models shows increased IL-1 expression after seizures, and IL-1 has proconvulsive properties when applied exogeneously. However, opposing results have been published as well. More research is needed to fully establish the role of IL-1 in seizure generation and epilepsy, and to explore possible new treatment strategies that are based on interference with intracellular signaling cascades that are initiated when IL-1 binds to its receptor.

Interleukin-10 is associated with resistance to febrile seizures: genetic association and experimental animal studies

PURPOSE

Febrile seizures (FS) are the most common form of childhood convulsions. Many reports have shown that a proinflammatory cytokine, interleukin-1 (IL-1) beta, may have a facilitatory effect on the development of FS. We have previously shown that the IL1B -511C/T single nucleotide polymorphism (SNP) is associated with simple FS of sporadic occurrence. The balance between pro- and antiinflammatory cytokines influences the regulation of infections and could, therefore, play a role in the pathogenesis of FS. Here, to determine whether pro- and antiinflammatory cytokine genes are responsible for the susceptibility to FS, we have performed an association study on functional SNPs of cytokine genes in FS patients and controls.

METHODS

The promoter SNPs of four inflammatory cytokine genes (IL6 -572C/G, IL8 -251A/T, IL10 -592A/C and TNFA -1037C/T) were examined in 249 patients with FS (186 simple and 63 complex FS) and 225 controls. Because the IL10 -592 SNP showed a positive association with FS, two additional SNPs (IL10 -1082A/G and -819T/C) were subjected to haplotype analysis. Furthermore, we examined the in vivo role of IL-10 in hyperthermia-induced seizures using immature animal models.

RESULTS

The frequencies of the IL10 -592C allele and -1082A/-819C/-592C haplotype were significantly decreased in FS as compared with in controls (p = 0.014 and 0.013, respectively). The seizure threshold temperature in the IL-10-administered rats was significantly higher than that in the saline-treated control ones (p = 0.027).

CONCLUSIONS

The present study suggests that IL-10 is genetically associated with FS and, contrary to IL-1beta, confers resistance to FS.

FIRST: a practical approach to the causes and management of febrile seizures

During almost 4 decades of clinical practice of pediatrics and pediatric neurology, the senior authors have rarely made a formal presentation on the topic of "febrile seizures." In any large pediatric teaching hospital, questions regarding the diagnosis and management of febrile seizures are raised by medical students, pediatric residents, and adult and pediatric neurology residents. The acronym FIRST was developed as a teaching tool to present a simple and pragmatic clinical approach to children presenting with a single seizure or cluster of seizures in 1 day associated with a febrile illness before, during, or after the seizure event(s). FIRST refers to Febrile, Illness, Related, Seizure(s) and Template, with the latter representing an outline of the basic cause(s). The authors propose the use of the Table as a tool to help determine the underlying etiology of febrile seizures because this is the major factor affecting the choice of treatment.

Association study between interleukin 1 beta gene and epileptic disorders: a HuGe review and meta-analysis

Previous studies have examined the association of a single nucleotide polymorphism at the promoter region of interleukin 1B (IL-1 beta-511T) with temporal lobe epilepsy and febrile seizures susceptibility, but those studies have been inconclusive. Published studies up to March 2007 of temporal lobe epilepsy, febrile seizures and the IL-1 beta-511T single nucleotide polymorphism were identified by searches of Medline and Embase databases. Meta-analysis of temporal lobe epilepsy and febrile seizures case-control data were performed to assess the association of IL-1 beta-511T with temporal lobe epilepsy, temporal lobe epilepsy with hippocampal sclerosis, febrile seizures, and other epileptic disorders. Pooled odds ratios (OR) were estimated by means of a genetic-model-free approach. The quality of the included studies was assessed by a score. The results show a modest association (OR, 1.48; 95% confidence interval, 1.09-2.00; P = 0.01) between the IL-1 beta-511T polymorphism and temporal lobe epilepsy with hippocampal sclerosis.

Primary human herpesvirus-6 infection in the central nervous system can cause severe disease

Human herpesvirus-6 (HHV-6) infection is common in infancy, and symptoms are usually mild. However, encephalitis and other neurologic complications have been reported. Primary HHV-6 infection has been rarely confirmed in the central nervous system. We studied 21 children with suspected HHV-6 infection, drawn from a prospective, large-scale study of neurologic infections in Finland. Human herpesvirus-6 polymerase chain reaction was performed on cerebrospinal fluid samples, and antibody tests were performed on serum and cerebrospinal fluid. We identified nine children, aged 3 to 24 months, who had HHV-6-specific nucleic acid in cerebrospinal fluid. Primary infection was confirmed by seroconversion of specific antibodies in six, whereas one had a fourfold increase, and one had a fourfold decrease, in the antibody titer supporting recent infection. Generalized and prolonged seizures appeared in six children, four had a rash, four had ataxia, and four had gastroenteritis. All but two had a high fever. At follow-up, four children had evident neurologic sequelae, ataxia, and developmental disability, and needed special education. Primary HHV-6 infection may invade the central nervous system, and can cause neurologic symptoms and potentially permanent disability in children aged <or=2 years. The possibility of HHV-6 infection must be considered when treating acutely ill children, and especially those with convulsions.