EEG spectral analysis in children with febrile delirium

Febrile delirium is defined as an acute and transient confusional state with high fever. There are very few reports on febrile delirium, although fever is one of the commonest symptoms in children. We previously found a posterior slowing in the electroencephalogram (EEG) of delirious patients with fever. The purpose of this study is to evaluate the features of occipital slow waves by spectral analysis and to find a parameter associated with clinical improvement.

METHODS

Digital EEG tracings were investigated by Fourier analysis in 20 patients aged from 2 to 13 years. The fast Fourier transform (FFT) was computed for 20 s tracing from the P3-A1 and P4-A2 derivations. The spectral analysis of EEG was repeated in 7 patients. The tracings of 34 control subjects were also analyzed by FFT. EEG of a febrile, nine-year-old girl without delirium was also studied.

RESULTS

Febrile delirium was seen during the first three days of fever. The episodes lasted up to 10 min. Four patients showed febrile delirium again after admission but they became conscious a few minutes later. The relative power in the delta frequency band was increased in 65% of patients with preservation of the occipital alpha rhythm. In addition, repeated febrile delirium did not cause worsening of the posterior slowing. The duration of abnormal EEG was only a few days and the decrease of relative power in the delta frequency band was the best parameter of clinical improvement. Posterior slowing was also found in a febrile patient without delirium.

CONCLUSION

Febrile delirious children showed the characteristic clinical and spectral analytical features and the numerical data of EEG facilitate the comparison of the serial findings.

Adult-onset epilepsy and history of childhood febrile seizures: a retrospective study

BACKGROUND

Children with febrile seizures (FS) are at higher risk of developing epilepsy. There is robust literature on epilepsy with onset in childhood following FS but very little on the same issue in adults.

AIMS

We intended to assess the association between adult-onset epilepsy and history of childhood FS.

SETTINGS

The neurology clinic of a university hospital.

DESIGN

A retrospective study.

MATERIALS AND METHODS

Records of 101 consecutive adults (>14 years old) who were referred to our hospital with adult-onset seizures were reviewed and the patients and their families were interviewed to assess the medical history.

STATISTICAL ANALYSIS

Chi-square test and Mantel-Haenszel method.

RESULTS

Of the 101 patients, 9 were excluded for reasons of bacterial meningitis, recent head trauma, brain tumor, tricyclic antidepressants' overdose and missing reliable data of the childhood FS event. Thirty-one (33.7%) of the remaining 92 patients had history of FS in the childhood (71% men). Localization-related epilepsies were significantly associated with history of FS [Odds ratio: 3.29; (95% CI, 1.30-8.06)] ( (2)= 5.49, df = 1, P=0.012) when compared to other epilepsies and epilepsy syndromes. An initial unprovoked simple partial seizure was also significantly associated with a positive history of FS [Odds ratio: 8.05; (95% CI 2.88-22.45)] ( (2)= 15.86, df = 1, P< 0.001).

CONCLUSIONS

Localization-related epilepsies and partial seizures seem to be associated with a history of FS in childhood. This warrants more investigation to understand the mechanism as well as a possible pathology common in both localization-related epilepsies and FS in the affected probands.

Recurrence of febrile seizures in the respiratory season is associated with influenza A

OBJECTIVES

To investigate the association of viral infections and febrile seizures (FS).

STUDY DESIGN

From April 1998 to April 2002, a prospective, population-based study was carried out among general practitioners to assess the incidence of FS in their practices. Data thus obtained were compared with the incidence of common viral infections recorded in a national registry. Poisson regression analysis was performed to investigate whether the season or the type of infection was associated with the variation observed in FS incidence.

RESULTS

Throughout the 4-year period, 267 of 303 (88%) of general practitioners in the Dutch province of Friesland participated in the study. The estimated observation period was approximately 160,000 patient-years. We registered 654 cases of FS in 429 children. The estimated incidence of FS was 2.4 in 1000 patient-years. Poisson regression analysis revealed a positive correlation between recurrent FS and influenza A ( P = .01).

CONCLUSIONS

Our study suggests a relation between recurrent FS and influenza A. Influenza vaccination should be considered in all children with a history of FS.

Uncommon complication of herpes simplex encephalitis

A 9-year-old-girl who had herpes simplex encephalitis developed impending uncal herniation requiring surgical decompression. This case highlights the development of an uncommon complication despite the early initiation of treatment with acyclovir.

Hodgkin' s disease with fulminant non-alcoholic steatohepatitis

We report a woman with daily febrile episodes who developed fulminant hepatic failure. A percutaneous liver biopsy demonstrated non-alcoholic steatohepatitis, with no evidence of neoplastic infiltration. Post-mortem examination revealed stage IV Hodgkin's disease with trivial liver involvement. Rapidly progressive steatohepatitis causing acute liver failure may be a paraneoplastic presentation of Hodgkin's disease, possibly mediated by cytokines.

Fever after Immunization: Current Concepts and Improved Future Scientific Understanding

Fever is a common clinical complaint in adults and children with a variety of infectious illnesses, as well as a frequently reported adverse event following immunization. Although the level of measured temperature indicative of a "fever" was first defined in 1868, it remains unclear what role fever has as a physiologic reaction to invading substances, how best to measure body temperature and compare measurements from different body sites, and, consequently, how to interpret fever data derived from vaccine safety trials or immunization safety surveillance. However, even with many aspects of the societal, medical, economic, and epidemiologic meanings of fever as an adverse event following immunization (AEFI) still elusive, it is a generally benign--albeit common--clinical sign. By standardizing the definition and means of assessment of fever in vaccine safety studies, thereby permitting comparability of data, we hope to arrive at an improved understanding of its importance as an AEFI.

Incidence of febrile seizures in thalassemic patients

BACKGROUND

Febrile seizures are the most common seizures in children. Their incidence is 2-5% or 4.8/1000 person-years. To date, the pathophysiology of febrile seizures is unknown. But several hypotheses have been proposed that it may relate with plasma iron level. Such low incidence in thalassemic patients whose plasma iron level is high could give some clues to this hypothesis.

PATIENTS AND METHOD

Four hundred and thirty thalassemic patients from the hematology clinic at two hospitals in Northeastern Thailand were consecutively enrolled between Febuary 2003 and January 2004. The authors reviewed all the medical records of the patients and interviewed their parents for occurrence of febrile seizures.

RESULTS

The patients included 208 males and 222 females with an age ranged of 6 months to 10 years (mean = 6.36 years). Twenty patients (4.7%) had siblings who had febrile seizures. There were 3 episodes out of 2,734 person-years. The incidence was 1.10 per 1,000 person-years (95% CI: 0.23 to 3.20). This was statistically lower than that of the general population (p-value = 0.002). Therefore, the rate in thalassemic patients was 4.4 times less than that of the general population (95% confidence interval: 1.4 to 22.6).

CONCLUSIONS

The incidence of febrile seizures in thalassemic patients was very low compared to that of the general children population. Thus, iron overload may be a major factor involving the brain metabolism that prevents febrile seizures.

MMR vaccination and febrile seizures: evaluation of susceptible subgroups and long-term prognosis

CONTEXT

The rate of febrile seizures increases following measles, mumps, and rubella (MMR) vaccination but it is unknown whether the rate varies according to personal or family history of seizures, perinatal factors, or socioeconomic status. Furthermore, little is known about the long-term outcome of febrile seizures following vaccination.

OBJECTIVES

To estimate incidence rate ratios (RRs) and risk differences of febrile seizures following MMR vaccination within subgroups of children and to evaluate the clinical outcome of febrile seizures following vaccination.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study of all children born in Denmark between January 1, 1991, and December 31, 1998, who were alive at 3 months; 537,171 children were followed up until December 31, 1999, by using data from the Danish Civil Registration System and 4 other national registries.

MAIN OUTCOME MEASURES

Incidence of first febrile seizure, recurrent febrile seizures, and subsequent epilepsy.

RESULTS

A total of 439,251 children (82%) received MMR vaccination and 17,986 children developed febrile seizures at least once; 973 of these febrile seizures occurred within 2 weeks of MMR vaccination. The RR of febrile seizures increased during the 2 weeks following MMR vaccination (2.75; 95% confidence interval [CI], 2.55-2.97), and thereafter was close to the observed RR for nonvaccinated children. The RR did not vary significantly in the subgroups of children that had been defined by their family history of seizures, perinatal factors, or socioeconomic status. At 15 to 17 months, the risk difference of febrile seizures within 2 weeks following MMR vaccination was 1.56 per 1000 children overall (95% CI, 1.44-1.68), 3.97 per 1000 (95% CI, 2.90-5.40) for siblings of children with a history of febrile seizures, and 19.47 per 1000 (95% CI, 16.05-23.55) for children with a personal history of febrile seizures. Children with febrile seizures following MMR vaccinations had a slightly increased rate of recurrent febrile seizures (RR, 1.19; 95% CI, 1.01-1.41) but no increased rate of epilepsy (RR, 0.70; 95% CI, 0.33-1.50) compared with children who were nonvaccinated at the time of their first febrile seizure.

CONCLUSIONS

MMR vaccination was associated with a transient increased rate of febrile seizures but the risk difference was small even in high-risk children. The long-term rate of epilepsy was not increased in children who had febrile seizures following vaccination compared with children who had febrile seizures of a different etiology.

Placing the risk of seizures with pediatric vaccines in a clinical context

In this review we discuss the relationship between commonly administered childhood vaccines such as diphtheria-tetanus-whole cell pertussis (DTP) and measles-mumps-rubella (MMR), and the risk of nonfebrile and febrile seizure. We summarize data from the Vaccine Safety Datalink Study and other studies that suggest that DTP and MMR vaccine are associated with a transiently increased risk of febrile seizures, and cause between 5-9 and 25-34 additional extra febrile seizures per 100 000 immunized children, respectively. DTP and MMR do not appear to increase the risk of nonfebrile seizures. We discuss some methodologic challenges in studies of vaccines and seizures. Because there is no adequate comparison group that would allow for the study of seizures long after vaccination, studies of seizures are limited to acute events shortly following vaccination. Additionally, while seizures following vaccination are worrisome to parents and physicians alike, observational studies of the neurodevelopmental outcomes of these children are particularly problematic. We discuss how such studies are confounded by the natural history of predisposition to febrile seizures and by the increased diagnostic scrutiny that children with febrile seizures might undergo. Nevertheless, current data suggest that children with febrile seizures do not experience long-term negative effects.Finally, we discuss the creation of new clinics designed specifically to assist physicians in managing the vaccination of children with a personal or family history of seizures. Data from these clinics suggest that vaccination is safe for children with a personal or family history of seizures, but statistical power has been limited. We conclude by discussing the introduction of new vaccines, and note that, even with widespread use, it will take many years before we can be knowledgeable about the risk of rare events with these newly licensed products.

[Questions of epileptogenesis and prevention in symptomatic epilepsies]

Symptomatic epilepsies usually report themselves after a longer period of time after brain injury, after the so-called latent period. During this period progressive functional and structural changes occur which finally cause an increased excitatory condition. The process of epileptogenesis may be examined in animal models, such as in the kindling, status epilepticus, hypoxicischaemic models. Data gained from such sources support the hypothesis that the first injury results in a lower seizure threshold, but genetical and environmental factors also contribute to the development of epilepsy and most probably further insults may be needed. The development of epilepsy can be traced back to several reasons. In spite of this, the latent period provides opportunity for the prevention of epilepsy or for the influence of epileptogenesis in such a manner that later treatment can become more successful. Prevention should be an aim in clinical practice, as well. Medication used presently are more like to have anticonvulsive properties and their antiepileptogenic effect is questionable. Due to this fact, development of new drugs is necessary with new theoretical background. The most important influence on the incidence of epilepsy in recent years has been provided by the improvement in neonatal care. This highlights the fact that such optimal medical care should be provided in the acute period of brain injury which can terminate or lessen the risk of epilepsy.

[Diagnosis of epilepsy]

0.5-1% of the population suffers from epilepsy, while another 5% undergoes diagnostic evaluations due to the possibility of epilepsy. In the case of suspected epileptic seizures we face the following questions: Is it an epileptic seizure? The main and most frequent differential-diagnostic problems are the psychogenic non-epileptic seizures ("pseudo-seizures") and the convulsive syncope, which is often caused by heart disorders. Is it epilepsy? After an unprovoked seizure, the information on recurrence risk is an important question. The reoccurrence is more possible if a known etiological factor is present or the EEG shows epileptiform discharges. After an isolated epileptic seizure, the EEG is specific to epilepsy in 30-50% of cases. The EEG should take place within 24 hours postictally. If the EEG shows no epileptiform potentials, a sleep-EEG is required. What is the cause of seizures? Hippocampal sclerosis, benign tumors, and malformations of the cortical development are the most frequent causes of the focal epilepsy. Three potentially life-threatening conditions may cause chronic epilepsy: vascular malformations, tumors, and neuroinfections. The diagnosis in theses cases can usually be achieved by MRI, therefore, MRI is obligatory in all epilepsies starting in adulthood. The presence of epileptogenic lesion has a prognostic significance in treatment. If the MRI shows a circumscribed lesion then the pharmacological treatment will likely to be unsuccessful, while surgery may result in seizure freedom. The new and quantitative MRI techniques, such as volumetry, T2-relaxometry, MR-spectroscopy, and functional MRI play a growing role in the epilepsy diagnosis.

[A study of the relationship between initial febrile seizures and human herpes virus 6, 7 infections]

The DNA detection of human herpes virus (HHV) 6, 7 was performed in the patients who visited to the Nakano children's hospital because of their initial febrile seizures (FS). Those patients included 35 boys and 21 girls under 3 years of age (mean: 1 year 4 months). DNAs of HHV 6, 7 in the mononuclear cells extracted from peripheral blood were detected in 84% of the patients. This study proved that at least 34% of initial FS are caused by HHV 6 or 7 infections. Forty-seven percents of the patients who were clinically diagnosed as exanthema subitum showed complex type FS. In conclusion, HHV 6 and 7 infections are often related to the occurrence of initial FS, which may be in part caused by their direct invasion to the central nervous system.

Interaction between endogenous nitric oxide and carbon monoxide in the pathogenesis of recurrent febrile seizures

The aim of the study was to investigate the interaction between nitric oxygenase (NOS)/nitric oxide (NO) and heme oxygenase (HO)/carbon monoxide (CO) system in the pathogenesis of recurrent febrile seizures (FS). On a rat model of recurrent FS, the ultrastructure of hippocampal neurons was observed under electron microscopy, and expression of neuronal NOS (nNOS) in hippocampus and NO formation in plasma were examined after treatment with ZnPP-IX, an HO-1 inhibitor. In the ultrastructure of hippocampal neurons, the expression of HO-1 in hippocampus and CO formation in plasma were examined after treatment with L-NAME, a NOS inhibitor. We found that hippocampal neurons were injured after recurrent FS. The gene and protein expression of nNOS and HO-1 increased markedly in hippocampus in FS rats, while CO formation in plasma increased markedly and the concentration of NO in plasma increased slightly. ZnPP-IX could worsen the neuronal damage of recurrent FS rats. However, it further increased the expression of nNOS and endogenous production of NO obviously. L-NAME alleviated the neuronal damage of recurrent FS rats, but decreased the expression of HO-1 and CO formation. The results of this study suggested that endogenous NOS/NO and HO/CO systems might interact with each other and therefore play an important regulating role in recurrent FS brain damage.

Evidence based guideline for post-seizure management in children presenting acutely to secondary care

This evidence based guideline covers the immediate management of a child presenting to hospital with a febrile or afebrile seizure, once the fit has stopped.

Febrile convulsion during the acute phase of Kawasaki disease

BACKGROUND

Although seizures occur in association with meningitis or encephalitis in Kawasaki disease, febrile convulsions in Kawasaki disease are considered to be extremely rare. The aim of the present study is to elucidate the incidence of febrile convulsion in the acute phase of Kawasaki disease, in Niigata City General Hospital, Niigata, Japan.

METHODS

The study included 177 patients with Kawasaki disease. Patients ranged in age from 2 months to 10 years (mean age 26.89 +/- 22.44 months). The study included 105 males and 72 females. The clinical records of Kawasaki disease patients were examined retrospectively.

RESULTS

Febrile convulsions were not recognized in these 177 patients throughout the course of the disease, despite the presence of a high grade fever and their young age. However, eight of the 177 patients had experienced simple febrile convulsions during other febrile illness except for those with Kawasaki disease. In the acute phase of Kawasaki disease, only two patients showed generalized convulsion associated with prolonged consciousness disturbance and pleocytosis in the cerebrospinal fluid.

CONCLUSION

The incidence of febrile convulsions in the acute phase of Kawasaki disease might be extremely low, confirming the results of previous reports. Kawasaki disease is characterized by systemic vasculitis and is sometimes complicated by intracranial vasculitis. The incidence of electroencephalographic abnormalities and pleocytosis in the cerebrospinal fluid is higher in patients with Kawasaki disease. However, the reason why febrile convulsions did not occur in the acute phase of Kawasaki disease remains unknown, despite the presence of central nervous system involvement.

Decrease in hospital admissions for febrile seizures and reports of hypotonic-hyporesponsive episodes presenting to hospital emergency departments since switching to acellular pertussis vaccine in Canada: a report from IMPACT

OBJECTIVE

Acellular pertussis vaccines were introduced with the promise of an improved safety profile compared with whole-cell vaccines. In 1997-1998, Canada adopted 1 combination acellular pertussis vaccine, having previously used 1 particular combination whole-cell pertussis vaccine. We hypothesized that the change would result in a decrease in hospitalization rates for seizures and reports of hypotonic-hyporesponsive episodes (HHEs) temporally related to pertussis vaccination.

METHODS

Active surveillance was performed between 1995 and 2001 by the Immunization Monitoring Program-Active monitors at 12 hospitals using standard case definitions. Seizures had to occur within 72 hours after immunization with a pertussis-containing vaccine or 5 to 30 days after immunization with measles-mumps-rubella vaccine. HHE episodes had to occur within 48 hours of receipt of a pertussis-containing vaccine. Poisson regression models were used to compare the average number of monthly admissions for seizures and HHEs before and after introduction of the acellular pertussis vaccine.

RESULTS

We found a 79% decrease in febrile seizures associated with receipt of pertussis vaccine but no significant decrease in febrile seizures temporally related to measles-mumps-rubella between 1995-1996 and 1998-2001. There was a 60% to 67% reduction in HHEs associated with pertussis-containing vaccines between the same time periods, depending on case definition.

CONCLUSIONS

The risks of febrile seizures and HHEs after pertussis-containing vaccine declined significantly with the introduction of acellular pertussis vaccine in Canada. Active surveillance systems are important for detecting trends in uncommon adverse events after routine immunizations.

Management of febrile convulsion: scene in a regional hospital

OBJECTIVE

To determine whether practice parameters are applied to the management of children with febrile convulsion.

DESIGN

Retrospective study.

SETTING

Paediatric department of a public hospital, Hong Kong.

METHODS

Practice parameters of the American Academy of Pediatrics and audit measures recommended by the Joint Working Group of the Research Unit of the Royal College of Physicians and the British Paediatric Association were employed as standards. Records between January and April 2000 with the diagnostic coding of febrile convulsion, convulsion, status epilepticus, or meningitis/encephalitis/encephalopathy were reviewed. Areas assessed were appropriate documentation of hospital records and unit statistics (adverse outcomes, inappropriate investigations and treatment).

RESULTS

Ninety-four consecutive records were evaluated. In the documentation of hospital notes, accurate description of seizure was observed in 92%, incorrect diagnosis or coding in 12%, and presence/absence of signs of meningitis and parental counselling documented in 64% and 85%, respectively. Regarding unit statistics, investigations performed included a complete blood count, blood glucose, serum calcium, serum electrolytes, renal function tests, liver function tests, chest X-ray, and urinalysis. The mean number of routine investigations was seven. The average length of stay was 2 days. There were no cases of delay in the diagnosis of central nervous system infection. Inappropriate investigations and treatment were as follows: electroencephalography 11%, computed tomography brain scan 2%, and maintenance anticonvulsants 2%. All patients were discharged home with panadol regardless of clinical state.

CONCLUSIONS

The present study showed that the use of unnecessary investigations was common. Investigations, though resulting in significant expense, proved to be of little diagnostic value. Diagnostic procedures should be performed only when specifically called for by the patient's condition or medical history.

Rotavirus gastroenteritis associated with afebrile convulsion in children: clinical analysis of 40 cases

BACKGROUND

The purpose of this study was to evaluate the clinical manifestations and outcomes of hospitalized children with afebrile seizures following rotavirus gastroenteritis.

METHODS

We conducted a retrospective study enrolling patients under 18 years old who were admitted to our hospital during a 10-year period with the diagnosis of rotavirus gastroenteritis. We identified and further analyzed patients who presented with afebrile seizures, without previous seizure disorders, electrolyte imbalances or hypoglycemia. The statistical methods used were the Chi-square test, the Kruskal-Wallis test and the Mann-Whitney test.

RESULTS

Of 1937 patients, 40 patients (24 female and 16 male patients) met the inclusion criteria. The incidence of afebrile seizures following rotavirus gastroenteritis was 2.06%. The age of the patients ranged from 6 months old to 6 years old (mean, 1.9 years). The highest incidence of afebrile seizures was 4.67% in children 1 to 2 years of age (p < 0.001). Twenty-seven patients (67.5%) had two or more seizures, which usually were in clusters within a 24-hour period. No status epilepticus was observed. More than half of the patients (52.5%) suffered from seizures on the third day of diarrhea. Only five of 35 patients showed abnormal electroencephalogram (EEG) findings, which reverted to normal in four of the patients during the follow-up period. Most patients did not require long-term anticonvulsant treatment. During the follow-up period, all patients displayed normal psychomotor development without the recurrence of seizures, except in one patient who had a febrile convulsion.

CONCLUSION

We found that the course of afebrile seizures following rotavirus gastroenteritis was benign with satisfactory outcomes.

Pre-eclampsia and febrile convulsions

An association between pre-eclampsia and febrile convulsions has been reported, but the association may not be causal. We compared the risk of febrile convulsions in 14 974 children who had been exposed to pre-eclampsia in fetal life with that of 39 210 unexposed children. Children exposed to pre-eclampsia had a slightly increased risk of febrile convulsions, but the association was apparently caused by a shorter gestation in pre-eclamptic women.

Immunization Monitoring Program, Active: a model of active surveillance of vaccine safety

In Canada since 1993 the nation's passive system for reporting postimmunization adverse events has been supplemented by the active surveillance of inpatients at 10 to 12 pediatric referral centers, a system referred to as the Immunization Monitoring Program, Active. Participating centers are located from coast-to-coast and receive referrals from every province and territory. Approximately 20 percent of the population aged 0 to 12 years lives in the immediate vicinity of these centers. Nurse monitors at each center search for numerous target conditions, including postimmunization adverse events and vaccine-preventable infections. Vaccine safety observations have included (1) a substantial decrease in the risk of the development of febrile seizures and hypotonic-hyporesponsive episodes since the country switched from whole-cell to acellular pertussis-containing vaccines, (2) no evidence for encephalopathy resulting from the latter vaccines, (3) a generally benign outcome with postimmunization thrombocytopenia cases, and (4) an unexpectedly high rate of disseminated bacille Calmette-Guérin infections among aboriginal infants. Concomitant disease surveillance has been important for sustaining the surveillance system because few postimmunization adverse events require hospital admission.

Febrile seizures: an overview

Febrile seizures are the most common seizure disorder seen in children and most often occur between the ages of 6 months and 5 years. Febrile seizures are usually self-limited and need no further neurodiagnostic evaluation. Rarely does medication need to be prescribed. For children with prolonged or multiple febrile seizures, diazepam rectal gel (Diastat) is a safe and effective treatment. There are no significant long-term risks associated with febrile seizures.

An evidence and consensus based guideline for the management of a child after a seizure

OBJECTIVE

An evidence and consensus based guideline for the management of the child who presents to hospital having had a seizure. It does not deal with the child who is still seizing. The guideline is intended for use by junior doctors, and was developed for this common problem (5% of all paediatric medical attenders) where variation in practice occurs.

OPTIONS

Assessment, investigations (biochemistry, lumbar puncture, serum anticonvulsant levels, EEG in particular), and/or admission are examined.

OUTCOMES

The guideline aims to direct junior doctors in recognising those children who are at higher risk of serious intracranial pathology including infection, and conversely to recognise those children at low risk who are safe to go home.

EVIDENCE

A systematic review of the literature was performed. Articles were identified using the electronic data bases Medline (from 1966 to June 1998), Embase (from 1980 to June 1998) and Cochrane (to June 1998), and selected if they investigated the specified clinical question. Personal reviews were excluded. Selected articles were appraised, graded, and synthesised qualitatively. Statements of recommendation were made.

CONSENSUS

An anonymous, postal Delphi consensus development was used. A national panel of 30 medical and nursing staff regularly caring for these children were asked to grade their agreement with the statements generated. They were sent the relevant original publications, the appraisals, and literature review. On the second and third rounds they were asked whether they wished to re-grade their agreement in the light of other panellists' responses. Consensus was defined as 83% of panellists agreeing with the statement. Recommendations in brief: For afebrile seizures all children should have their blood pressure recorded, but no other investigations are routine although a seizing or somnolent child should have blood glucose measured; all children under 1 year should be admitted. For seizures with fever, clinical signs indicating the need to treat as meningitis are given. Children should be admitted if they are under 18 months old, have had a complex seizure, or after pretreatment with antibiotics.

VALIDATION

The guideline has undergone implementation and evaluation in a paediatric accident and emergency department, the results of which will be published separately. Only one alteration was made to the guideline as a result of this validation process, which is included here.

Voxel based morphometry of grey matter abnormalities in patients with medically intractable temporal lobe epilepsy: effects of side of seizure onset and epilepsy duration

OBJECTIVES

To investigate the use of whole brain voxel based morphometry (VBM) and stereological analysis to study brain morphology in patients with medically intractable temporal lobe epilepsy; and to determine the relation between side, duration, and age of onset of temporal lobe epilepsy, history of childhood febrile convulsions, and grey matter structure.

METHODS

Three dimensional magnetic resonance images were obtained from 58 patients with left sided seizure onset (LSSO) and 58 patients with right sided seizure onset (RSSO), defined using EEG and foramen ovale recordings in the course of presurgical evaluation for temporal lobectomy. Fifty eight normal controls formed a comparison group. VBM was used to characterise whole brain grey matter concentration, while the Cavalieri method of modern design stereology in conjunction with point counting was used to estimate hippocampal and amygdala volume. Age and sex were used as confounding covariates in analyses.

RESULTS

LSSO and RSSO patients showed significant reductions in volume (using stereology) and grey matter concentration (using VBM) of the hippocampus, but not of the amygdala, in the presumed epileptogenic zone when compared with controls, but hippocampal (and amygdala) volume and grey matter concentration were not related to duration or age of onset of epilepsy. LSSO and RSSO patients with a history of childhood febrile convulsions had reduced hippocampal volumes in the presumed epileptogenic zone compared with patients without such a history. Left amygdala volume was also reduced in LSSO patients with a history of childhood convulsions. VBM results indicated bilateral thalamic, prefrontal, and cerebellar GMC reduction in patients, which correlated with duration and age of onset of epilepsy.

CONCLUSIONS

Hippocampal sclerosis is not necessarily the consequence of recurrent temporal lobe seizures. A major cause of hippocampal sclerosis appears to be an early aberrant neurological insult, such as childhood febrile seizures. Secondary brain abnormalities exist in regions outside the presumed epileptogenic zone and may result from recurrent seizures.

Genetic and environmental factors in febrile seizures: a Danish population-based twin study

The relative importance of genetic and environmental factors in the etiology of febrile seizures was estimated using a large, unselected population-based twin sample. A total of 34,076 twins (aged 12-41 years), recruited from the Danish Twin Registry, were screened for febrile seizures by questionnaire. Information was obtained from 11,872 complete pairs. Concordance rates, odds ratios and correlations were used to assess the degree of similarity in monozygotic (MZ) and dizygotic (DZ) twins. Model fitting and estimation of heritability (proportion of the population variance attributable to genetic variation) were performed using standard biometrical methods. Significantly higher probandwise concordance rates were found for MZ compared with DZ twins (0.36 and 0.12, P < 0.01). Odds ratios and correlations showed a similar pattern. An etiological model including additive genetic effects and individual-specific environmental factors provided the best fit to the data with a heritability for febrile seizures of 70% (95% CI: 61-77%). The remaining 30% of the variation could be attributed to individual-specific environmental factors. In conclusion, this study has confirmed a major impact of genetic factors in the etiology of febrile seizures. Future studies aimed at identifying the specific genetic factors and environmental exposures involved in determining febrile seizure risk are clearly warranted.

Retrospective population-based assessment of medically attended injection site reactions, seizures, allergic responses and febrile episodes after acellular pertussis vaccine combined with diphtheria and tetanus toxoids

BACKGROUND

Since 1997 diphtheria-tetanus toxoids-acellular pertussis (DTaP) vaccines have been recommended for the five dose pertussis vaccination series. To assess rates of medically attended injection site reactions (ISRs), seizures, allergic responses and febrile episodes after Tripedia DTaP vaccine administered in the context of routine care, we conducted a retrospective assessment among the population of Group Health Cooperative from 1997 through 2000.

METHODS

Administrative databases were used to identify medical visits linked with diagnostic codes potentially indicative of ISRs, seizures, allergic responses and febrile episodes after DTaP vaccine. Outcomes were confirmed by medical record review.

RESULTS

During the study period 76 133 doses of DTaP were administered. Of the 26 ISRs identified, 6 followed DTaP given as the fourth dose and 18 followed DTaP given as the fifth dose, for rates of 1 per 2779 and 1 per 900 vaccinations, respectively. During the study period nearly all children receiving DTaP as the fifth dose had received whole cell pertussis vaccine for their primary series, and all of the fifth dose ISRs were among that group. Four of those reactions involved the entire upper arm. The rate of febrile seizures within 2 days of DTaP among children <2 years of age was 1 per 19 496 vaccinations.

CONCLUSIONS

The low rate of febrile seizures and other serious events confirms the safety of DTaP vaccine. The risk of medically attended ISRs was highest with DTaP given as the fifth dose, and whole arm reactions were reported, but medically attended ISRs were relatively uncommon and were self-limited.

[Infantile acute lobar nephritis]

INTRODUCTION

Acute lobar nephronia is a focal interstitial inflammation of the kidney healing well on conservative therapy.

OBJECTIVE

Authors call attention on this rare pathological entity and emphasize the role of the imaging modalities in making the diagnosis. Short literature review is also given.

PATIENT AND METHODS

An 11 months old babyboy presented with febrile seizure and palpable right flank mass. Abdominal sonography and CT were done.

RESULTS

Urine analysis gave evidence of upper urinary tract infection. Hyperechogenic solid mass in the right kidney was seen on sonography. Diagnosis of infection suspected on sonography has been confirmed by abdominal CT scan and possibility of tumor has been ruled out. Acute lobar nephronia was diagnosed and the patient has been treated successfully with antibiotics.

CONCLUSION

Acute lobar nephronia may mimic both abscess and tumor. Differential diagnosis is very important because treatment of acute lobar nephronia is nonsurgical.

The pathogenesis of febrile seizures: is there a role for specific infections?

Although fever is regarded as the main trigger in the pathogenesis of febrile seizures (FS), it is not supposed to be the unique causative factor. In FS, there is a strong familial predisposition. This does not exclude infections as a causative factor because subtle genetic polymorphisms have been demonstrated to affect the course of infections. We review the literature on: (1) the role of fever, especially the height of temperature, its cause, and metabolic effects induced by temperature; (2) the role of heredity; (3) the role of cytokines which play a role in the induction of fever; and (4) the role of type of infection, with emphasis on newly identified agents and improved diagnostic techniques. With modern molecular techniques such as PCR, viruses have been detected in the CSF far more often than previously thought, even in the absence of pleocytosis of the CSF. This makes it difficult to distinguish FS from acute encephalitis. FS may be caused by neuroinvasion or intracerebral activation of viruses. Further studies should focus on these options because therapeutic intervention is possible and may prevent late sequelae such as recurrent FS and subsequent epilepsy.

Febrile convulsions and sudden infant death syndrome

It has been suggested that sudden infant death syndrome (SIDS) and febrile convulsions are related aetiologically. We compared the risk of SIDS in 9877 siblings of children who had had febrile convulsions with that of 20 177 siblings of children who had never had febrile convulsions. We found no support for the shared susceptibility hypothesis.

Risk factors of febrile seizures among preschool children in Alexandria

The study design was a case control study to identify the risk factors of febrile seizures. Total sample of 28 children, their ages ranging from 12 to 60 months, with febrile seizure were matched with control group of 60 children of the same age group with fever without seizure. The peak age of first febrile seizure was between 6 and 12 months. The significant risk factors were upper respiratory tract infection (p < 0.05), family history of febrile seizures (p < 0.0001). Prematurity (p < 0.005), problems during gestation (p < 0.005), family history of epilepsy (p < 0.005) and problem during labour (p < 0.0005).

[Neurologic emergencies in the child]

Febrile seizures are the main causes of seizures in infants and children. They are caused by the fever without infectious of nervous central system. The diagnosis of acute encephalitis should be suspected in febrile children whose level of consciousness is progressively altered and who present with partial seizures and motor deficit. The two most classical etiologies of ataxias are cerebellar involvement or deep sensibility disorder. Acute drug poisoning and viral infections are the most common causes. Intracranial hypertension is due to an abnormal increase in cerebrospinal fluid pression. Acute form may be a life threatening or complication of chronic intracranial hypertension. Despite its high frequency, benign form should be remain a diagnosis of exclusion.

An incident case-control study of first unprovoked afebrile seizures in children: a population-based study of pre- and perinatal risk factors

PURPOSE

The aim of this prospective incident community-based study was to assess the influence of pre- and perinatal risk factors in children in whom an unprovoked afebrile epileptic seizure later developed.

METHODS

From November 1, 1985, until June 30, 1987, 75 children aged 0-15 years with a first unprovoked afebrile seizure were identified. After exclusion of cases with neonatal seizures (n = 14), two controls per case were selected from the same province in northern Sweden matched by age and sex. Files from maternity wards and pediatric clinics could be traced for 58 cases and 109 controls. These formed the study group.

RESULTS

In the univariate analysis, the risk for an unprovoked afebrile seizure was significantly elevated for birth order (OR = 9.3; CI, 2.2-39), vaginal bleeding (OR = 17; 95% CI, 3.5-85), onset of hypertension during pregnancy (OR = 4.8; CI, 1.3-17), cesarean section (OR = 18; 95% CI, 3.7-88), short or long gestational age (OR = 6.7; 95% CI, 2.0-22), and an Apgar score < or =6 at any time (OR = 3.8; 95% CI, 1.2-12). None of these six factors was present in 48.3% of the cases and 89% in the controls. A combination of two or more risk factors found to be significant in the univariate analysis showed a pronounced increased risk for seizures (OR = 19; 95% CI, 5.6-65). In the multivariate analysis, the following characteristics remained statistically significant: vaginal bleeding, gestational age, and Cesarean section. Furthermore, smoking also was identified as a risk factor in the multivariate analysis (OR = 3.4; 95% CI, 1.1-10).

CONCLUSIONS

Both pre- and perinatal factors may be associated with later development of epileptic seizures in children. However, in many of the cases, no such factors were identified.

Influenza A infection is an important cause of febrile seizures

OBJECTIVES

To compare the incidence of febrile seizures in children hospitalized for influenza A infection with parainfluenza and adenovirus infection and to examine the hypothesis that children hospitalized for influenza A (variant Sydney/H3N2) during the 1998 season in Hong Kong had more frequent and refractory seizures when compared with other respiratory viruses, including the A/Wuhan H3N2 variant that was present in the previous year.

METHODS

Medical records of children between 6 months and 5 years of age admitted for influenza A infection in 1998 were reviewed. For comparison, records of children of the same age group with influenza A infection in 1997, and with parainfluenza and adenovirus infections between 1996 and 1998 were reviewed. Children who were afebrile or who had an underlying neurologic disorder were excluded.

RESULTS

Of children hospitalized for influenza A in 1998 and 1997, 54/272 (19.9%) and 27/144 (18.8%) had febrile seizures, respectively. The overall incidence of febrile seizures associated with influenza A (19.5%) was higher than that in children hospitalized for parainfluenza (18/148; 12.2%) and adenovirus (18/199; 9%) infection, respectively. In children who had febrile seizures, repeated seizures were more commonly associated with influenza A infection than with parainfluenza or adenovirus infection (23/81 [28%] vs 3/36 [8.3%], odds ratio [OR] 4.3, 95% confidence interval: 1.2 to 15.4). Alternatively, children with influenza A infection had a higher incidence (23/416, 5.5%) of multiple seizures during the same illness than those with adenovirus or parainfluenza infection (3/347, 0.86%; OR 6.7, 95% confidence interval: 2.0-22.5.) The increased incidence of febrile seizures associated with influenza A was not attributable to differences in age, gender, or family history of febrile seizure. Multivariate analysis, adjusted for peak temperature and duration of fever, showed that hospitalized children infected with infection A had a higher risk of febrile seizures than those who were infected with parainfluenza or adenovirus (OR 1.97). Influenza A infection was a significant cause of febrile seizure admissions. Of 250 and 249 children admitted to Queen Mary Hospital for febrile seizures in 1997 and 1998, respectively, influenza A infection accounted for 27 (10.8%) admissions in 1997 and 54 (21.7%) in 1998. During months of peak influenza activity, it accounted for up to 35% to 44% of febrile seizure admissions. In contrast, parainfluenza, adenovirus, respiratory syncytial virus, and influenza B had a smaller contribution to hospitalizations for febrile seizures, together accounting for only 25/250 (10%) admissions in 1997 and 16/249 (6.4%) in 1998.

CONCLUSION

The influenza A Sydney variant (H3N2) was not associated with an increased risk of febrile seizures when compared with the previous influenza A Wuhan variant (H3N2) or H1N1 viruses. However, in hospitalized children, influenza A is associated with a higher incidence of febrile seizures and of repeated seizures in the same febrile episode than are adenovirus or parainfluenza infections. The pathogenesis of these observations warrants additional studies. Complex febrile seizures, particularly multiple febrile seizures at the time of presentation, have been thought to carry an adverse long-term prognosis because of its association with a higher incidence of epilepsy. Repeated febrile seizures alone, particularly if associated with influenza A infection, may not be as worrisome as children with complex febrile seizures because of other causes, which requires additional investigation. This may subsequently have an impact on reducing the burden of evaluation in a subset of children with complex febrile seizures.