CSF total protein: normal values. A re-appraisal and discussion of its value in diagnosis of acoustic neuromas.

A reference material of total cerebrospinal fluid protein (CSF protein) from 53 men and 45 women is presented. Lowry's Folin-phenol method for determining CSF protein has been used unchanged in this laboratory since 1964, with normal values ranging from 0.2 to 0.4 g/l. In this new reference material higher values were found with the 0.05--0.95 fractile interval for normal CSF protein determined to 0.29--0.88 g/l. This implies that the value of determining CSF protein in diagnosis of acoustic neuromas is most questionable. Among the medium sized tumours there were statistically significant increased values, but no clinical significance. The large tumours showed both statistically as well as clinically significant increased protein, but these tumours can be easily diagnosed by other means. A more detailed determination of CSF protein is discussed.