[The use of nitrous oxide as a contrast medium during fractionated gas encephalography in halane-nitrous-oxide anesthesia].

40 children were employed as test cases in fractionated gas encephalography using Halan-nitrous oxide anesthesia, and the level of cerebrospinal pressure, the röntgenoparent quality of the extracerebral spaces and the duration of postencephalographical symptoms were examined using air and nitrous oxide as contrast media. In the course of the examination the cerebrospinal pressure showed a tendency to rise when air was introduced, to fall when nitrous oxide was introduced. After instillation of N2O however the filling of the subarachnoid space was over so quickly that it could not be included in the assessment. Sufficient röntgenograms were obtained for all diagnostic demands through 'hybrid filling', (introduction of nitrous oxide into the ventricles, introduction of air into the subarachnoid spaces). With the aid of the results obtained from this examination attempts will be made to derive differentiated indications for filling with nitrous oxide.