Alpha-synuclein is a potential biomarker in the serum and CSF of patients with intractable epilepsy

PURPOSE Intractable epilepsy is a brain disorder characterized by recurrent seizures and intracellular alpha-synuclein (αS) deposits; however, the neurobiological basis of this protein accumulation is still poorly understood. This is the first study aiming to assess whether the increase of αS concentrations in the serum and CSF (cerebrospinal fluid) could serve as a marker for αS deposition in the brain and diagnosis of epilepsy. METHODS This investigation enrolled 67 epileptic patients (40 with intractable epilepsy; 13 with newly diagnosed epilepsy, and 14 with non-intractable epilepsy). CSF and serum samples were collected from each patient and were assessed by ELISA. RESULTS It was established that the concentration of αS in the CSF and serum was elevated in the epilepsy patients, as compared to the control. However, the results of the subgroup analysis revealed that levels of αS in the serum and CSF were increased in the intractable epileptic patients (CSF: 11.12 ± 4.18 ng/ml; serum: 52.93 ± 22.11 ng/ml), whereas there was no difference in the groups with the newly diagnosed (CSF: 34.998 ± 14.96 ng/ml; serum: 7.77 ± 3.41 ng/ml) and non-intractable epilepsy (CSF: 8.93 ± 4.83 ng/ml; serum: 34.11 ± 17.53 ng/ml). CONCLUSION Overall, we found that the rise of the αS content in the serum and CSF may facilitate the identification of intractable epilepsy; therefore, the determination of αS rates may serve as a valuable prognostic marker in the clinical assessment.