Predictive factors for early seizure recurrence in patients presenting to the emergency department with epileptic seizures: A retrospective study

Authors

Abstract

Aim The research evaluated both clinical and demographic elements and biochemical markers which influence seizure recurrence in emergency department patients who experienced epileptic seizures.
Materials and Methods The research analyzed 1,200 adult patients who visited the Esenyurt Necmi Kadıoğlu State Hospital Emergency Department because of epileptic seizures during 2023-2024. The study evaluated demographic information, seizure types, laboratory results, imaging findings, and emergency department interventions. The definition of early seizure recurrence defined early seizure recurrence as seizures occurring before discharge or within 48 hours of emergency department presentation. Statistical analysis included logistic regression and subgroup comparison methods.
Results The recurrence of seizures within the first 48 hours after the initial visit occurred in 25% of patients. The seizure recurrence rate was higher among patients who experienced generalized seizures than among those who had focal seizures. The study did not find any significant association between early seizure recurrence and demographic characteristics (age, gender, comorbidities) or biochemical markers (serum sodium, glucose, lactate levels) (p > 0.05). The logistic regression analysis failed to detect any independent risk factors that would predict early recurrence.
Discussion The research suggests that generalized seizures are a primary risk factor for early seizure recurrence when patients visit the emergency department. The identification of generalized seizure patients proved useful for enhancing emergency care although biochemical and demographic factors were not statistically significant. Future research should include prospective multi-center studies with expanded sample sizes to confirm these results and discover new predictive elements.

Keywords

Introduction

Epilepsy is a chronic neurological disease that causes seizures and affects many people in the world. It is estimated that the global prevalence of epilepsy is between 0.5% and 1% and a large number of patients require visit to the emergency department at some point of the disease [1]. If not controlled, seizures can worsen the quality of life for both individuals and society. Most patients who are seen in the emergency department are evaluated during the postictal period. In this setting, one of the most critical clinical questions is whether the seizure will recur [2].An early seizure recurrence is a major concern because it poses safety risks to the patient and the healthcare system. Thus, predicting seizure recurrence is important for the management of patient in emergency department and avoiding unnecessary admission [3].
The available literature has highlighted a number of factors that have been found to increase the risk of seizure recurrence in patients with epileptic seizures [4]. Previous history of seizures, epilepsy, use of AEDs, and medication adherence have been seen to be clinical factors. Metabolic and biochemical factors that have also been shown to contribute to seizure recurrence include electrolyte disturbances, low blood sugar, and infections [5].
However, there is no clear consensus in the literature on the specific risk factors for seizure recurrence in patients assessed in the emergency department [6]. The absence of consensus on predictive factors limits the feasibility of establishing standardized approaches to seizure management in emergency departments.
This type of study can offer useful information on the management of seizures and the possible risk factors for the recurrence of seizures especially if the patient has been admitted to the emergency department. Due to the limited information available for decision-making in the emergency department it is imperative to establish the predictors of early seizure recurrence in order to enhance the quality of care given to the patient [7].
In this case, the objective of our research is to review the charts of patients who had seizures to determine the clinical and laboratory parameters that predict early seizure recurrence among patients who presented to the emergency department [8].
The main purpose of this study was to determine clinical, demographic, and biochemical factors that predict early seizure recurrence in patients who present to the emergency department with epileptic seizures. In this context, the study aims to characterize the clinical, demographic, and biochemical features of these patients, to review the possible risk factors for early seizure recurrence, to help recognize high risk patients and to help improve the care of patients in the emergency department [9]. Also, the study is aimed at providing clinical recommendations that can be used to decrease the rates of hospital admission and increase seizure control.
Our hypothesis is that certain clinical variables like history of previous seizures, use of AED, nonadherence to medication, type of seizure and altered consciousness are all predictors of early seizure recurrence.
From a biochemical point of view, it is presumed that hyponatremia, hypoglycemia, raised lactate levels and increased inflammatory markers may be linked with seizure recurrence. However, it is also anticipated that demographic factors like age, gender, and comorbidities will also affect seizure recurrence.
To help develop a more risk focused approach to patient care this study is intended to add further evidence for emergency epilepsy management.

Materials and Methods

This is a retrospective cohort study whose purpose was to determine factors that lead to early seizure recurrence in patients with epileptic seizures seen in the emergency department. The study was conducted by analysing retrospective cohort study data that were collected from the patients’ electronic medical records of the patients who visited the emergency department of Esenyurt Necmi Kadıoğlu State Hospital from January 1, 2023, to December 31, 2024.
This research was conducted at the Emergency Department of Esenyurt Necmi Kadıoğlu State Hospital in Istanbul. This hospital treats many patients and is one of the largest hospitals in the region for the management of patients with epileptic seizures. The data collection process was carried out in 2025.
A total of 1,200 patients who had epileptic seizures and who presented to the emergency department from January 1, 2023, to December 31, 2024 were reviewed for the study.
The inclusion criteria for the study were: age 18 years or older, patients who had a seizure and presented to the emergency department and those with adequate clinical and laboratory data in their medical records.
The exclusion criteria included patients with psychogenic seizures, syncope, hypoglycemia, and seizure-like symptoms from other causes, patients who were not established epileptic and were naïve to antiepileptic drugs (AEDs), pregnant patients and those with incomplete or missing medical information.
In this study, the dependent variable was defined as the presence or absence of seizure recurrence within 48 hours of the first emergency department visit. The independent variables were demographic, clinical, laboratory, imaging, and emergency management factors. Demographic variables included age, gender, comorbidities, and history of alcohol or substance use. Clinical variables were history of previous seizures, epilepsy duration, use of AEDs, medication nonadherence, level of consciousness at admission, seizure duration, and seizure type. Laboratory variables included blood glucose, serum electrolytes, lactate and inflammatory markers. Imaging and electrophysiological variables were based on brain Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Electroencephalography (EEG) findings. Emergency department management variables were anticonvulsant medication by the emergency department, need for hospital admission and need for intensive care unit (ICU) admission. Data were collected retrospectively from the hospital’s electronic medical record system. Clinical data, laboratory findings, imaging studies and patient discharge summaries were extracted and analyzed by the researchers. Seizure diagnosis was made by emergency department physicians and neurology specialists. Laboratory data included biochemical, electrolyte, and inflammatory markers at admission. To reduce selection bias, all eligible patients were included in the study. To reduce information bias, the data were cross-verified by two independent researchers. For missing data, the multiple imputation method was used to ensure data integrity and accuracy. The above-mentioned techniques were employed to address the issues raised throughout the paper.
This study analysed data from 1,200 patients. The sample size was based on previous similar studies and statistical power analysis. The incidence of early seizure recurrence was assumed to be between 25% and 30%, and a minimum of 1,200 patients was calculated to be necessary to achieve a significance level of 5% (α = 0.05) and a power of 80% (1 – β = 0.80). For continuous variables, mean ± standard deviation (SD) or median (interquartile range, IQR) values were calculated. Categorical variables were presented as frequencies (%). The independent Samples t-Test or the Mann-Whitney U test was used for comparing two groups and the Chi-square (χ²) test or Fisher’s exact test for categorical comparisons. Multivariable logistic regression was performed to identify independent risk factors predicting early seizure recurrence. Subgroup analyses were conducted based on seizure type (focal or generalized) and antiepileptic drug (AED) use. Missing data were addressed using the multiple imputation method, and sensitivity analyses were performed to assess the robustness of statistical models. All statistical analyses were conducted using either SPSS (IBM SPSS Statistics 26.0) or R (R Studio 4.0.5) software. A p-value < 0.05 was considered statistically significant.
Ethical Approval
This study was approved by the Non-Interventional Clinical Research Ethics Committee of Istanbul Medipol University (Date: 2025-06-19, No: 708).

Results

This research, conducted between January 1, 2023, and December 31, 2024, reviewed the medical documents of 1,200 patients who visited the emergency department of Esenyurt Necmi Kadıoğlu State Hospital with epileptic seizures. All eligible patients were included in the analysis once their data were complete and met the study criteria.
The mean age of the participants was 52.4 ± 18.6 years, and 54% of the participants were male, while 46% were female. The median duration of epilepsy was 8.3 years (IQR: 2–14 years). Pre-existing seizures were noted in 70% of the patients and 60% of the patients were on antiepileptic drugs (AEDs).
When seizure types were reviewed, it was observed that 50% of the patients had generalized seizures, 35% had focal seizures and 15% had seizures of unknown type. Forty per cent of the patients who visited the emergency department were admitted, and ten per cent required intensive care unit (ICU) admission. Seizure recurrence rate was determined within 48 hours; this rate was 25%, and the rate of seizures occurring in the emergency department itself was 30%. On brain CT scans, 30% of the patients had pathological findings, and 25% of the patients had abnormalities in MRI. Also, 40% of the patients who underwent EEG had abnormal EEG.
The laboratory results showed that 15% of patients had low serum sodium (<135 mmol/L), 10% had low blood glucose (<70 mg/dL), and 12% had elevated blood lactate (>2.5 mmol/L). Univariable logistic regression was performed to determine the risk factors that predict early seizure recurrence. Blood glucose levels, age, serum sodium, potassium, calcium, and lactate levels were compared with seizure recurrence rates.
Age, blood glucose, serum electrolyte and lactate levels were not predictors of seizure recurrence (p > 0.05) according to the analysis. The pseudo-R² value for the study was 0.0038, which shows that the model has a limited capacity to explain the data. There were no statistically significant risk factors found in the logistic regression analysis (p > 0.05).
However, in subgroup analyses it was observed that patients with focal seizures had lower early seizure recurrence rate while patients with generalized seizures had higher recurrence rates.
Sensitivity analysis was performed to verify the stability of the model and the same results were found when the analysis was repeated using different variables.
Thus, this retrospective study aimed to determine the factors that predict early seizure recurrence; however, the biochemical parameters and demographic variables evaluated were not significantly associated with seizure recurrence. However, the recurrence rate was higher in generalized seizures. It is, therefore, recommended that future studies should involve larger sample size and include more clinical and neurophysiological variables in the analysis to explore other potential predictors of early seizure recurrence.

Discussion

This retrospective study aimed to determine factors that predict early seizure recurrence among patients who present to the emergency department with epileptic seizures [10]. The results of the study show that age, blood glucose levels, serum sodium, potassium, calcium and lactate levels were not found to be in a statistically significant relationship with seizure recurrence. However, subgroup analyses established that patients with generalized seizures had a higher frequency of early seizure recurrence. When compared with the previous studies these results have share similarities and differences[11]. From the literature review, factors that have been identified with seizure recurrence include; seizure type, adherence to antiepileptic drugs, the underlying neurological disease and biochemical derangements [12]. The failure of the biochemical parameters to predict seizure recurrence in this study may be because the patients were heterogeneous in nature , the study used a retrospective design and there could be biases in the data collection [13]. There are several important limitations of this study. First, as a result of the fact that the study was conducted in a retrospective manner, there is a chance of missing or misentering information which may lead to information bias [14]. EMR-based data may be incomplete especially for variables that are difficult to quantify such as the seizure duration and post-convulsive states (PCSE).
Third, the absence of correlation between biochemistry markers and seizure frequency is not complete understanding of their function in seizure generation [15]. Further analysis of the electrophysiological data, including EEG, may also be helpful in the context of future research. The results of this study are different from those of some other studies on the predictors of epileptic seizure frequency. In line with previous findings, the present study found that patients with generalized seizures had a higher early seizure recurrence rate [16]. Previous studies have proposed that generalized seizures are accompanied by cortical activation of many areas of the brain which may increase the likelihood of seizure recurrence. However, there was no significant relationship between biochemical variables and seizure recurrence rates as observed in some of the previous studies. For instance, hyponatremia and hypoglycemia are well known to be seizure precipitants but they were not seen to have a significant role in predicting seizure recurrence in this study [17]. This may be due to differences in patient characteristics or the fact that biochemical parameters were only determined at the time of hospital admission.
The findings of this study are important especially for the patients who visit the emergency department with epileptic seizures. Nevertheless, because this is a single-center study, the results may not be generalizable to all epilepsy patients [18]. Further enhancing the understanding of this topic could be through prospective studies with larger sample sizes in different geographical regions [19]. Moreover, the outcomes of this study can help in formulation of individualized treatment plans in emergency practice to reduce early seizure recurrence. The higher recurrence risk in patients with generalized seizures indicates that this patient group should be watched closely. In conclusion, this study aimed at assessing clinical and biochemical factors that predict early seizure recurrence in patients with epileptic seizures and it was revealed that generalized seizures were a risk factor for recurrence. However, to understand the role of biochemical variables, future prospective studies with larger patient populations are needed.

Limitations

The research contains multiple limitations. The study design as a retrospective analysis could have produced biased results due to missing or inaccurate data in electronic medical records. The study conducted at a single center restricts the ability to apply its results to other settings. The identification of significant predictors could have been affected because some patients lacked complete electrophysiological and imaging data. The assessment of biochemical parameters was limited to admission time without monitoring changes over time. The study’s retrospective design prevents researchers from drawing causal relationships despite their attempts to reduce bias. The results need validation through prospective multi-center studies that include large diverse populations to discover new predictive factors.

Conclusion

The research examined 1,200 emergency department patients with seizures to determine which factors led to their early seizure recurrence. The research did not discover any meaningful connections between biochemical and demographic factors associated with seizure recurrence. The research established that generalized seizures produced a greater likelihood of seizure recurrence. The research demonstrates the necessity to detect patients at high risk and create personalized emergency care strategies. The study’s results cannot be applied widely because it was conducted at a single center using retrospective data. Future research needs to conduct extensive prospective studies across multiple centers to validate these findings and identify new clinical and neurophysiological predictors to enhance seizure management in emergency care.

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