Differential Diagnosis of Seizure and Syncope by the Means of Biochemical Markers in Emergency Department Patients

Seizure and syncope have similar clinical symptoms but different etiologies. Hence, differential diagnosis is crucial prior to intervention. This study evaluates the diagnostic importance of neuron specific enolase (NSE), creatine phosphokinase (CPK), and serum lactate dehydrogenase (LDH) for admitting patients with seizure medical history to emergency department (ED) in order for differential diagnosis between syncope and seizure.

Patients with a short‑lasting loss of consciousness admitted to the ED were recruited. All patients with a short‑lasting loss of consciousness were eligible and EEG was conducted several times and was taken over a long period. Patients were then divided into two groups of seizure and syncope. The biochemical markers levels of all the eligible patients were measured by a reputable laboratory.

In order to define specificity and sensitivity of different levels of biomarkers and the optimal cut‑off points, ROC curves for each biomarker of syncope and seizure patients admitted to ED were performed. AUC for NSE, CPK, and LDH were 0.973 ± 0.023, 0.827 ± 0.047, and 0.836 ± 0.043 respectively in 95% confidence level. Cut‑off points for NSE, CPK, and LDH were determined 25.12, 218.09, and 193.88 respectively.

It was concluded that NSE, CPK and LDH levels were different significantly in seizure patients compared to syncope ones. The seizure group showed an increase in NSE, CPK and LDH level. Determining biomarkers level for differential diagnosis of seizure and syncope can be applied as a supplementary test in addition to tests like EEG.