Diurnal variation in febrile convulsions

Febrile Seizures: An Updated Narrative Review for Pediatric Ambulatory Care Providers

BACKGROUND

While generally self-limited, febrile seizures result in significant familial distress. Ambulatory pediatric care providers must be prepared to counsel families on the causes, risk factors, management principles, and prognosis of children with febrile seizures.

OBJECTIVE

To provide an updated, evidence-based review of febrile seizures focused on the needs of an ambulatory pediatric care provider.

METHODS

A narrative review of the literature prioritizing landmark articles, metanalyses, longitudinal population longitudinal cohort studies and national level guidelines.

RESULTS

Febrile seizures are aberrant physiological responses to fever in children caused by complex interactions of cytokine mediated neuroinflammation, environmental triggers, and genetic predisposition. Other than investigations to determine fever etiology, routine bloodwork, lumbar punctures, neuroimaging and electroencephalograms are low yield. The general prognosis is excellent, however, clinicians should be aware of long-term outcomes including: cognitive impairment with non-simple febrile seizures; neuropsychiatric associations; recurrent febrile seizure and epilepsy risk factors; and the association between complex febrile seizures and sudden unexpected death. Children with a high risk of recurrence, complex febrile seizures, limited access to care, or extreme parental anxiety may benefit from intermittent oral diazepam prophylaxis.

CONCLUSION

Clinicians should consider four management priorities: 1) terminating the seizure; 2) excluding critical differential diagnoses; 3) investigating fever etiology; and 4) providing adequate counselling to families. The clinical approach and prognosis of febrile seizure can be based on subtype. Children with non-simple (i.e. complex or febrile status epilepticus) febrile seizures require closer care than the vast majority of children with simple febrile seizures, who have excellent outcomes.

Development of a prediction nomogram model of recurrent febrile seizures in pediatric children

The purpose of this study is to develop a prediction nomogram of recurrent febrile seizures in pediatric children based on the identified predictors for developing recurrent febrile seizures. This is a retrospective observational study. The medical records of 320 febrile seizure-afflicted children admitted to Zhoushan Women and Children Hospital from March 2019 to January 2023 were retrospectively reviewed. Children were divided into the recurrent febrile seizures group and the non-recurrent febrile seizures group. The predictors of recurrent febrile seizures were identified by univariate and multivariate analyses. A prediction nomogram model was developed via R software. The performance of the nomogram was internally validated to assess the model's discrimination and consistency, and decision curve analysis was employed to assess clinical utility. There were 41 out of 320 cases that had recurrent febrile seizures during the observation period, with a 12.81% prevalence rate of recurrent febrile seizures. The predictors of recurrent febrile seizures were young age at the first febrile seizures, a family history of febrile seizures in a first-degree relative, diurnal variation of initial febrile seizures occurrence, gender, and a low level of C-reactive protein. The area under the receiver operating characteristic curve of the nomogram is 0.795 (95% confidence interval: 0.720-0.871). Calibration plots and the result of the Hosmer-Lemeshow test (P = 0.472) reveal satisfactory consistency. Decision curve analysis showed a significant net benefit of the nomogram.

CONCLUSIONS

The prediction nomogram model demonstrates good performance and clinical utility, which would be a convenient tool for the detection of children in pediatrics with high-risk recurrent febrile seizures. It is useful for pediatric medical staff to provide early medical interventions and family counseling.

WHAT IS KNOWN

• A proportion of children experience recurrences of febrile seizures. • Recognition of risk factors for recurrent FS in pediatrics would be useful for the prediction of risk probabilities and help provide tailored counseling and follow-up.

WHAT IS NEW

• A nomogram model is developed for risk prediction of recurrent febrile seizures in this study, which would be a convenient risk prediction tool in pediatrics. • The predictor of diurnal variation of recurrent febrile seizures is with new ideas.

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.

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.

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.

Diurnal occurrence of complex febrile seizure and their severity in pediatric patients needing hospitalization

Several studies describing the diurnal occurrence of febrile seizures have reported greater seizure frequency early or late in the evening relative to midnight or early morning. However, no articles have reported on the diurnal occurrence of complex febrile seizure. Moreover, no studies have addressed the relationship between seizure severity and diurnal occurrence. We retrospectively evaluated complex febrile seizures in 462 children needing hospitalization, and investigated the relationship between severity and diurnal occurrence according to four categorized time periods (morning, afternoon, evening, and night). Our study showed that complex febrile seizures occurred most often in the evening, peaking around 18:00 (18:00-18:59), and least often at night (02:00-02:59). In addition, the frequency with which patients developed status epilepticus or needed anticonvulsant treatments was also lower during the night. However, the seizure duration and the proportion of the patients who needed anticonvulsant treatment were the same among the four time periods. Furthermore, we compared three subclasses (repeated episodes of convulsions, focal seizures, and prolonged seizures (≧15min)), two of the complex features (focal seizures and prolonged seizures), and all complex features among the four time periods. However, they were the same among the four time periods. Taken together, our data indicate that although the severity of seizures was stable over a 24-hour period, the occurrence of seizures in our cohort of pediatric patients with complex febrile seizures requiring hospitalization was highest in the evening and lowest at night.

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.

Diurnal and Seasonal Occurrence of Febrile Seizures

Investigators from University of Oulu, Finland, evaluated the diurnal and seasonal occurrence of the first febrile seizures (FS) in 461 children in a population-based study of 1522 children.

Diurnal and seasonal occurrence of febrile seizures

BACKGROUND

Febrile seizures are the most common seizures in children, but their pathogenesis remains unknown. Some studies have suggested an association between the light-dependent secretion of melatonin and the occurrence of febrile seizures. The diurnal and seasonal occurrence of febrile seizures could clarify the role daylight plays in febrile seizures.

METHODS

In Finland, summer days are long and bright and winter days are short and dark. We evaluated the diurnal and seasonal occurrence of the first febrile seizures in 461 children and adjusted them according to the epidemiology of the febrile episodes in a population-based study of 1522 children.

RESULTS

The first febrile seizure most often occurred in the evening, peaking between 6 and 10 PM (31%), and least often at night, in the early morning hours between 2 and 6 AM (8%) (P < 0.001). This diurnal pattern repeated itself in different seasons according to variance in daylight duration. Febrile seizures occurred irregularly throughout the year, most frequently in winter, concurrently with the febrile episodes, and least frequently in summer; this seasonal variation in the occurrence of febrile seizures disappeared however when adjusted for the number of febrile events.

CONCLUSIONS

We found clear diurnal and seasonal variations in the occurrence of febrile seizures, even though they did not follow the amount of daylight. Our findings do not support the hypothesis that the diurnal and seasonal variation of daylight explains the occurrence of febrile seizures. Moreover, febrile events associated strongly with the occurrence of febrile seizures.

Diurnal and twenty-four hour patterning of human diseases: acute and chronic common and uncommon medical conditions

The symptom intensity and mortality of human diseases, conditions, and syndromes exhibit diurnal or 24 h patterning, e.g., skin: atopic dermatitis, urticaria, psoriasis, and palmar hyperhidrosis; gastrointestinal: esophageal reflux, peptic ulcer (including perforation and hemorrhage), cyclic vomiting syndrome, biliary colic, hepatic variceal hemorrhage, and proctalgia fugax; infection: susceptibility, fever, and mortality; neural: frontal, parietal, temporal, and occipital lobe seizures, Parkinson's and Alzheimer's disease, hereditary progressive dystonia, and pain (cancer, post-surgical, diabetic neuropathic and foot ulcer, tooth caries, burning mouth and temporomandibular syndromes, fibromyalgia, sciatica, intervertebral vacuum phenomenon, multiple sclerosis muscle spasm, and migraine, tension, cluster, hypnic, and paroxysmal hemicranial headache); renal: colic and nocturnal enuresis and polyuria; ocular: bulbar conjunctival redness, keratoconjunctivitis sicca, intraocular pressure and anterior ischemic optic neuropathy, and recurrent corneal erosion syndrome; psychiatric/behavioral: major and seasonal affective depressive disorders, bipolar disorder, parasuicide and suicide, dementia-associated agitation, and addictive alcohol, tobacco, and heroin cravings and withdrawal phenomena; plus autoimmune and musculoskeletal: rheumatoid arthritis, osteoarthritis, axial spondylarthritis, gout, Sjögren's syndrome, and systemic lupus erythematosus. Knowledge of these and other 24 h patterns of human pathophysiology informs research of their underlying circadian and other endogenous mechanisms, external temporal triggers, and more effective patient care entailing clinical chronopreventive and chronotherapeutic strategies.