[Selenium concentration in the cerebrospinal fluid of children].

Following a wet digestion of 0.5-2.0 ml cerebrospinal fluid in an open system using 2.0 ml nitric acid and 1.0 ml perchloric acid (240 degrees C) and a reduction step with 1.0 ml hydrochloric acid, Selenium can be determined polarographically after adding 100 micrograms Copper(II)-ions to the analyte (15 ml; water/perchloric acid). Selenium concentrations in cerebrospinal fluid of children younger than one year (2.49 +/- 1.67 ng/ml) are significantly higher (p = 0.0074) than those of older children (1.28 +/- 0.97 ng/ml). Independent of the children age and diseases the Selenium concentrations correlate distinctly with cell numbers and protein contents. A correlation between Selenium content and cell numbers alone could not be proved. The nonsignificant differences between the Selenium concentrations in cerebrospinal fluids of children with hydrocephalus, leukemia (with or without involvement of the central nervous system), and other diseases, respectively, may be interpreted by considering the protein content of the cerebrospinal fluid and the age of the children.