Elevated serum neuron-specific enolase in patients with temporal lobe epilepsy: a video-EEG study

Established markers of brain damage, neuron-specific enolase (NSE) and S-100b protein (S-100), may increase after status epilepticus, but whether a single tonic-clonic or complex partial seizure induces elevation of these markers is not known. Furthermore, it is unclear whether the risk of seizure-related neuronal damage in temporal lobe epilepsy (TLE) differs from that in extratemporal lobe epilepsies (XTLE). The aim of this study was to analyze NSE and S-100 in patients with TLE and XTLE after acute seizures. The levels of NSE and S-100 were measured in serum before (0h) and at 3, 6, 12, and 24h after acute seizures in 31 patients during inpatient video-EEG monitoring. The patients were categorized into the TLE and the XTLE group based on video-EEG recordings and MRI findings. Fifteen patients had TLE and 16 XTLE. Index seizures were mainly complex partial seizures (n=21). In TLE mean+/-S.D. values for NSE levels (mug/L) were 8.36+/-2.64 (0h), 11.35+/-3.84 (3h), 13.48+/-4.49 (6h), 12.95+/-5.46 (12h) and 10.33+/-3.13 (24h) (p=0.006, ANOVA). In XTLE the changes were not significant (p=0.3). There was less increase in the levels of S-100 in TLE (p=0.05) and no significant change in XTLE (p=0.4). The levels of markers of neuronal damage were increased in patients with TLE, not only after tonic-clonic but also after complex partial seizures. These data suggest that TLE may be associated with brain damage.