Can immature granulocyte (IG), an inflammatory marker, be used in the differential diagnosis of epilepsy and non-epileptic psychogenic seizure?

Aims: Differential diagnosis of epilepsy and psychogenic non-epileptic seizures (PNES) is a great challenge. Intense neuronal activity during epileptic seizures can cause neuroinflammation. Immature granulocyte (IG) is a new inflammatory marker analyzed in hemogram. This study investigated the role of IG in differentiating epilepsy from PNES. Methods: In this retrospective study, patients who applied to the emergency department for the first time with seizures and were diagnosed with epilepsy/PNES (clinical evaluation and electroencephalography) after included the seizure by the neurology clinical follow-up. Of the 84 patients, 54 had epilepsy, and 30 had PNES. Hemogram analyses were performed within 2 hours of the onset of the seizure. Results: The IG count was 0.03 x109/L (0.02-0.06) and 0.03 x109/L (0.02-0.05) in the epilepsy and PNES groups, respectively. The two groups had no statistically significant difference (p=0.291). Only serum C-reactive protein (CRP) levels significantly differed between the two groups (p=0.031). The ROC curve analysis for the CRP test yielded a serum CRP value of 2.35 mg/L, with a sensitivity of 0.57 and a specificity of 0.73, as the optimal cut-off value for distinguishing epilepsy from PNES. The ROC analysis for the AUC yielded an estimate of 0.64 (95% confidence interval: 0.52-0.77). Conclusion: In conclusion, only CRP was useful in differentiating epilepsy from PNES in the study. However, the IG count did not help to separate the two seizures. Therefore, these findings should be confirmed by further prospective studies with large samples assessing the IG count. This study evaluating the IG count, a new inflammatory marker, will contribute to the literature.