Cerebrospinal fluid serotonin in brain tumor and other neurological disorders determined by a spectrophotofluorometric technique.

Abstract A spectrophotofluorometric technique was applied to a study of the serotonin content of cerebrospinal fluid obtained from 208 neurological patients (233 samples) and 23 normal controls (23 samples). The concentrations of 5-hydroxytryptamine in each of the latter was less than 20 mμg. per milliliter. The amine occurred with appreciably greater frequency and concentration in primary (30 samples) as compared with metastatic brain tumor (30 samples). In one instance, that of an acoustic neuroma, the level of serotonin in the spinal fluid was greater than the concomitant level in the serum. There was no relationship between the individual levels of spinal fluid serotonin and protein. However, in both primary and secondary cerebral neoplasms and in the nontumor group, the mean protein concentration tended to be higher in the positive than in the negative fluids. The neurofibroma was the only spinal cord tumor manifesting an increased concentration of cerebrospinal fluid serotonin. Elevated spinal fluid levels of 5-hydroxytryptamine were also associated with recent cerebrovascular diseases, acute cerebral trauma, grand mal seizures, hepatic coma, and diffuse central nervous system disease of unknown etiology with cerebral atrophy. It is suggested in the latter that the neurological findings may be related to an abnormality in serotonin metabolism.