NONHOMOGENEOUS DISTRIBUTION OF 5-HYDROXYINDOLEACETIC ACID AND HOMOVANILLIC-ACID IN LUMBAR CEREBROSPINAL-FLUID OF MAN

The volume of the lumbar sac measured in 4 subjects was 15.5 ml. Exactly 15 ml of lumbar CSF (L-CSF) was permitted to flow freely out during a lumbar puncture in 20 neurological patients and small samples of the L-CSF were collected in the beginning (sample 1), at the middle (sample 2) and at the end (sample 3) of this procedure either for 5-HIAA [5-hydroxyindoleacetic acid] or HVA [homovanillic acid] measurement. The concentrations of 5-HIAA and HVA increased in an exponential manner from sample 1 to sample 3. CSF in the lumbar sac is apparently not a homogeneous fluid as is generally believed, and certain rules have to be followed in the sampling of the L-CSF to obtain reproducible biochemical data.