Diurnal and Seasonal Occurrence of Febrile Seizures

On hidden factors and design-associated errors that may lead to data misinterpretation: An example from preclinical research on the potential seasonality of neonatal seizures

Unintentional misinterpretation of research in published biomedical reports that is not based on statistical flaws is often underrecognized, despite its possible impact on science, clinical practice, and public health. Important causes of such misinterpretation of scientific data, resulting in either false positive or false negative conclusions, include design-associated errors and hidden (or latent) variables that are not easily recognized during data analysis. Furthermore, cognitive biases, such as the inclination to seek patterns in data whether they exist or not, may lead to misinterpretation of data. Here, we give an example of these problems from hypothesis-driven research on the potential seasonality of neonatal seizures in a rat model of birth asphyxia. This commentary aims to raise awareness among the general scientific audience about the issues related to the presence of unintentional misinterpretation in published reports.

Evaluation of Patients Presenting to the Pediatric Emergency Department with Seizures during the COVID-19 Pandemic

The coronavirus disease 2019 pandemic has led to significant changes in hospital visits worldwide. The admission rates have remarkably decreased. This study investigates the characteristics of 104 patients (54 girls, 50 boys) who presented to our pediatric emergency department (ED) with seizures during the pandemic between May 2020 and May 2021. Regarding seizure type, 84 generalized and 20 focal seizures had occurred. Tonic, tonic–clonic, clonic, and hypomotor seizures were seen in descending order. Thirty-seven patients were diagnosed with epilepsy, and 32 patients with first afebrile, 25 first febrile, and 10 recurrent febrile seizures. No patients had acute symptomatic seizures. In 85 patients, the seizures had stopped before the ED visit; only one lasted >60 minutes. Benzodiazepines were administered as a first-line drug. Demographical features, electroencephalogram (EEG), and cranial imaging findings, laboratory test results, and distribution by month and by the hour of ED visit were analyzed. Study data was in accordance with the literature by seizure types, seizure management, and cranial imaging rates but differed by distribution in terms of month and the hour of ED visit. The EEG abnormality rate was higher among the first afebrile seizure cases. The number of patients with seizures was 69, that is, 0.3% of emergency admissions, for the 4 months of 2019 before the pandemic, and 104, that is, 0.4% of emergency admissions for the whole initial year of the pandemic thereafter. So, the number of patients with seizures had decreased, but their rate had increased, which could be attributed to a decrease in the number of nonurgent presentations to the ED during the pandemic.

Study of Febrile Seizure among Hospitalized Children of a Tertiary Centre of Nepal: A Descriptive Cross-sectional Study

INTRODUCTION

Febrile seizure is the commonest cause of seizure in children and appears mostly between 6-60 months of life. The objective of this study is to find out the prevalence of febrile seizure among hospitalized children of a tertiary centre of Nepal.

METHODS

This is a descriptive cross-sectional study conducted in a teaching hospital of central Nepal, from 2014 January to 2019 December. After obtaining ethical clearance from Institutional Review Committee (Reference number: 2019-038), clinical and demographic data was retrieved from patient record retrospectively and reviewed for completeness and accuracy; those fulfilling the definition of febrile seizure were enrolled in the study. Convenience sampling technique was used. The data was analyzed using Statistical Packages for Social Sciences Version 25. Point estimate is done at 95% Confidence Interval and frequency and proportion was calculated.

RESULTS

Out of 4890 cases admitted during the study period, 214 (4.37%) (3.80%-4.94% at 95% Confidence Interval) children were diagnosed with febrile seizure. One hundred thirty one (62%) children had a simple febrile seizure. In majority of the cases, seizure lasted for less than 5 minutes; however, 10 (4.6%) of them presented with febrile status epilepticus, 111 (52%) children had generalised tonic seizure and upper respiratory tract infection was the commonest cause of fever.

CONCLUSIONS

Prevalence of febrile seizure is significant among hospitalized children and simple febrile seizure is the commonest type. A substantial number of children present in febrile status epilepticus, even though the duration of febrile seizure is brief in most of the cases.

The effect of weather, air pollution and seasonality on the number of patient visits for epileptic seizures: A population-based time-series study

OBJECTIVE

The objective of the study was to explore the influences of seasonality, meteorological conditions, and air pollution exposure on the number of patients who visit the hospital due to seizures.

METHODS

Outpatient and inpatient data from the National Health Insurance Database of Taiwan from 2009 to 2013, meteorological data from the Meteorological Bureau, and air pollution exposure data from the Taiwan Air Quality Monitoring Stations were collected and integrated into daily time series data. The following data processing and analysis results are based on the mean of the 7 days' lag data of the 18 meteorological condition/air pollution exploratory factors to identify the critical meteorological conditions and air pollution exposure factors by executing univariate analysis. The average hospital visits for seizure per day by month were used as an index of observation. The effect of seasonality has also been examined.

RESULTS

The average visits per day by month had a significant association with 10 variables. Overall, the number of visits due to these factors has been estimated to be 71.529 (13.7%). The most obvious factors affecting the estimated number of visits include ambient temperature, CH₄, and NO. Six air pollutants, namely CH₄, NO, CO, NO₂, PM2.5, and NMHC had a significantly positive correlation with hospital visits due to seizures. Moreover, the average daily number of hospital visits was significantly high in January and February (winter season in Taiwan) than in other months (R² = 0.422).

CONCLUSION

The prediction model obtained in this study indicates the necessity of rigorous monitoring and early warning of these air pollutants and climate changes by governments. Additionally, the study provided a firm basis for establishing prediction models to be used by other countries or for other diseases.

Are there effects of lunar cycle on pediatric febrile seizure?: A single-center retrospective study (2005-2018)

BACKGROUND

Several studies have reported an association between seizure and the lunar cycle; however, results are conflicting. Thus, we investigated whether emergency department (ED) visits due to febrile seizure (FS) or FS plus were affected by lunar cycle.

METHODS

We reviewed the medical records of patients who were admitted to the ED with a main diagnosis of FS or FS plus from January 1, 2005 to August 31, 2018 (13 years 8 months), a period of 4991 days with 169 lunar cycles. During that period, we collected weather data such as mean temperature, average atmospheric pressure (AP), and humidity according to lunar phase (new moon, first quarter, full moon, and third or last quarter).

RESULTS

A total of 1979 patients were identified. We found male predominant with a mean age of 2.62 ± 2.09 years. Acute pharyngotonsillitis was the most common cause of fever, generalized tonic-clonic seizure was the most common type of seizure, and the mean peak body temperature was 38.77 ± 0.81 °C. The lunar cycle did not affect the onset or frequency of FS after adjustment; however, several factors, including season, O₃ and NO₂ concentrations, and holidays, were associated with FS.

CONCLUSION

We did not find an association between lunar cycle and FS or FS plus. However, several factors, including season, O₃, NO₂, and holidays were associated with FS or FS plus.

Low ambient temperature as the only meteorological risk factor of seizure occurrence: A multivariate study

BACKGROUND

The onset of epileptic seizures is influenced by weather, which is multifactorial. It is unknown which specific weather factors affect the occurrence of seizures.

OBJECTIVES

We studied the correlation between the onset of epileptic seizures and multiple weather parameters based on a population-based registry profile.

METHODS

We determined the number of patients who visited emergency services in Taiwan diagnosed as having epilepsy. Then we used a linear regression model to analyze the monthly average number of patients who received emergency treatment for epilepsy in relation to temperature, barometric pressure, accumulated precipitation, relative humidity, and hours of sunshine. The Poisson regression model was used to analyze multiple meteorological factors in relation to the number of daily emergency visits because of epilepsy. A receiver operating characteristic curve was used to determine the cutoff temperature for the occurrence of seizures.

RESULTS

Temperature appeared to be the robust factor for the onset of epilepsy. For every 1 °C decrease in temperature, there was a relative risk increase of 1.016 in the number of emergency visits as a result of epilepsy. Temperature lower than 18 °C had the best predictive value for seizure. Barometric pressure, accumulated precipitation, relative humidity, and the number of hours of sunshine were not related to the occurrence of seizures.

SIGNIFICANCE

Our results suggest that temperature is the only influential meteorological factor that affects seizure occurrence.

Febrile seizures: an overview

Background

Febrile seizures are the most common neurologic disorder in childhood. Physicians should be familiar with the proper evaluation and management of this common condition.

Objective

To provide an update on the current understanding, evaluation, and management of febrile seizures.

Methods

A PubMed search was completed in Clinical Queries using the key terms ‘febrile convulsions’ and ‘febrile seizures’. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews.

Results

Febrile seizures, with a peak incidence between 12 and 18 months of age, likely result from a vulnerability of the developing central nervous system to the effects of fever, in combination with an underlying genetic predisposition and environmental factors. The majority of febrile seizures occur within 24 hours of the onset of the fever. Febrile seizures can be simple or complex. Clinical judgment based on variable presentations must direct the diagnostic studies which are usually not necessary in the majority of cases. A lumbar puncture should be considered in children younger than 12 months of age or with suspected meningitis. Children with complex febrile seizures are at risk of subsequent epilepsy. Approximately 30–40% of children with a febrile seizure will have a recurrence during early childhood. The prognosis is favorable as the condition is usually benign and self-limiting. Intervention to stop the seizure often is unnecessary.

Conclusion

Continuous preventative antiepileptic therapy for the prevention of recurrent febrile seizures is not recommended. The use of intermittent anticonvulsant therapy is not routinely indicated. Antipyretics have no role in the prevention of febrile seizures.

The effects of weather on pediatric seizure: A single-center retrospective study (2005-2015)

BACKGROUND

Several studies have reported an association between seizure and the weather. However, reports are conflicting. Thus, we investigated whether emergency department visits due to seizure are affected by weather.

METHODS

We retrospectively analyzed 108,628 emergency department visits to Samsung Changwon Hospital by pediatric patients from January 2005 to December 2015. Among them, there were 3484 (3.2%) visits for any type of seizure. Seizures were categorized as febrile seizure, afebrile seizure, epilepsy, or status epilepticus. We used a distributed lag non-linear model with quasi-Poisson distribution to investigate the association between weather and pediatric seizure.

RESULTS

During this 11-year study period, over the half of total pediatric seizure patients were febrile seizure (53.5%) and the proportion for status epilepticus were the lowest (5.9%). Mean of mean temperature and diurnal temperature range were 14.7°C and 8.3°C. Mean humidity was 62.1%, mean of atmospheric pressure was 1015.5hPa and mean of sunshine was 6.3Hr. When considering the overall 0-15days lagged effect of weather, only mean temperature was significantly associated with emergency department visits. At lower temperatures, the number of emergency department visits increases and decreases at higher temperatures. All 4 types of seizure also showed similar patterns. In particular, only visits of febrile seizure were significantly associated with mean temperature.

CONCLUSION

We investigated the association weather and pediatric seizure by considering 0-15day lags. In particular, low mean temperature increase the emergency department visits for pediatric seizure and high mean temperature decrease the pediatric seizure. In addition, only febrile seizure of 4 seizure types was affected by mean average temperature.