Nicoletti F, Raffaele R, Falsaperla A, Paci R
Eur Neurol. 1981;20(1):9-12. doi: 10.1159/000115197.
Circadian variation of 5-hydroxyindoleacetic acid (5-HIAA) in the ventricular fluid of 5 neurosurgical cases is examined. The 5-HIAA level increases progressively during the day (highest values at 24.00 h) and returns to the initial level the following day at 6.00 h. The results are discussed.