Kinetics of Serum Neuron-Specific Enolase and Prolactin in Patients After Single Epileptic Seizures

Summary: Purpose: To investigate and compare the temporal profile of serial levels of neuron-specific enolase (NSE) and prolactin in serum from patients after single epileptic seizures.Methods: Measurement of NSE and prolactin by sensitive immunoassays in 21 patients with complex partial seizure (CPSs; n = 11) and secondarily generalized tonic-clonic seizures (SGTCSs; n = 10) during continuous video-EEG monitoring at four different time points (1, 3, 6, and 24 h after ictal event). Statistical analysis was performed by using a repeated-measures analysis of variance (ANOVA) model.Results: Mean ± SD values for NSE levels (ng/ml) were 12.5 ± 4.4 (1 h), 10.8 ± 3.8 (3 h), 11.1 ± 4.9 (6 h), and 8.2 ± 1.9 (24 h). The corresponding prolactin levels (mU/L) were 1,311 ± 1,034, 232 ± 158, 237 ± 175, and 251 ± 98. There was a significant decrease of NSE and prolactin levels over time (p < 0.001). The pair-wise comparison of NSE levels showed significant differences between the time points 1 vs. 24 h (p < 0.001), 3 vs. 24 h (p = 0.007), and 6 vs. 24 h (p = 0.009). In contrast, serum prolactin levels showed a significant difference between 1 vs. 3 h (p < 0.001) only. Most of the NSE levels remained normal after CPSs and SGTCSs. At 1 h after the seizure, only 33% of the subjects had increased NSE, whereas abnormal prolactin levels occurred with a sensitivity of 80%.Conclusions: In contrast to prolactin, serum NSE is not a sensitive marker of individual seizures. Only some individuals showed an increase of NSE beyond the prolactin-sensitive time frame after a single seizure, and mean NSE levels were not significantly increased compared with those of normal controls.