Normal CSF neuron-specific enolase and S-100 protein levels in patients with recent non-complicated tonic-clonic seizures

Purpose: Increased concentrations of the nervous-system-specific proteins n euron-specific enolase (NSE) and S-100 protein (S-100) have been measured w ith lesions in the CNS. Elevated levels of serum NSE (s-NSE) have been foun d in status epilepticus, but also after single epileptic seizures. Because larger studies addressing cerebrospinal fluid (CSF) levels of NSE or S-100 have not been performed, we measured CSF NSE and S-100 after tonic-clonic s eizures to search for evidence of neuronal and glial damage. Methods: 22 co nsecutive patients with single, previously undiagnosed and untreated tonic- clonic seizures were studied. Serum and CSF samples were collected within 2 4 h after seizure. 18 serum and CSF samples were measured from a control gr oup. Results: The mean CSF NSE was 8.9 ng/ml (range 0-28 ng/ml) and s-NSE 8 .2 ng/ml (range 5-15 ng/ml) in the patient group. The mean concentrations i n the control group were 13.1 ng/ml (range 3-24 ng/ml) and 8.0 ng/ml (range 5-12 ng/ml) respectively. The mean CSF S-100 was 3.17 mug/l (range 1.45-7. 02 mug/l) and serum S-100 0.05 mug/l(range 0-0.32 mug/l), and in controls 3 .19 mug/l (range 1.52-5.13 mug/l) and 0.08 mug/l (range 0-0.28 mug/l). Conc lusion: There were no significant differences between the mean concentratio ns of NSE or S-100 in CSF and serum between the epileptic group and control s. These results do not confirm the previous observation of elevated NSE-le vels after tonic-clonic seizures, which argues against neuronal or glial da mage after uncomplicated tonic-clonic seizures in unmedicated patients. (C) 2001 Elsevier Science B.V. All rights reserved.