The influence of ventricular tapping on S100 and NSE serum concentrations: preliminary results

Objective

Serum markers, e.g. the protein S100 and neuron specific enolase (NSE), are recognized to give additional information about the extension and prognosis of brain damage. In some of these patients, e.g. after SAHs and ICBs, it is necessary to insert a ventricular drainage. Whether the cannulation of the ventricle and the insertion of a ventricular drainage falsifies the serum concentrations of S100 and NSE is not known. The aim of this study was to get further information in this field.

Methods

In this prospective study we included 10 patients (5 women, 5 men, mean age 53.7 years) suffering from SAH (n = 5), ICB (n = 2), hydrocephalus (n = 2) and ischemia (n = 1). All patients underwent a ventricular tapping and an insertion of a ventricular drainage. Serum samples for estimation of S100 and NSE were collected before, directly after and 6 hours after insertion of the drainage. In addition we investigated the liquor directly after and 6 hours after insertion for S100 and NSE concentrations. The samples were analyzed by using the Liaison kits (Byk-Sangtec, Dietzenbach, Germany). For statistical work up we used the t-test.

Results

None of the patients showed a significantly increased S100 or NSE serum concentration after insertion of the drainage. The mean serum value of S100 before insertion was 0.49 μg/l, directly after 0.42 μg/l and 6 hours later 0.49 μg/l. The mean serum concentration of NSE before insertion was 18 μg/l, directly after 13.9 μg/l and 6 hours later 9.8 μg/l. The concentration of NSE in the cerebrospinal fluid directly after insertion were significantly higher compared to the serum concentration (85 μg/l versus 13.9 μg/l, mean, P < 0.05). The S100 concentration in the liquor was also higher, but failed to be statistically significant (418.8 μg/l versus 0.42 μg/l, mean).

Conclusion

Due to our preliminary results, the serum values of S100 and NSE seem not to be falsified by insertion of a ventricular drainage. So the prognostic value of these serum markers seems to be preserved despite the surgical manipulation. In addition the concentrations of these markers in the cerebrospinal fluid seem to be exceedingly higher compared to the serum concentrations, probably reflecting an intact blood–brain barrier.