Kinetics of serum neuron-specific enolase and prolactin in patients after single epileptic seizures

Purpose: To investigate and compare the temporal profile of serial levels o f 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 p atients with complex partial seizure (CPSs; n = 11) and secondarily general ized tonic-clonic seizures (SGTCSs; n = 10) during continuous video-EEG mon itoring 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 corres ponding 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 prolac tin levels showed a significant difference between 1 vs. 3 h (p < 0.001) on ly. Most of the NSE levels remained normal after CPSs and SGTCSs. At 1 h af ter the seizure, only 33% of the subjects had increased NSE, whereas abnorm al 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 bey ond the prolactin-sensitive time frame after a single seizure, and mean NSE levels were not significantly increased compared with those of normal cont rols.