On the relationship between l-DOPA therapy and CSF monoamine metabolites in parkinson's disease

Summary HVA, the main dopamine catabolite, was shown to be decreased in CSF of parkinsonian patients. A significant relationship was also shown between clinical improvement and HVA concentration increase in CSF. It was, however, recently claimed that such increase was not specific.A study on the CSF concentrations of HVA and 5-HIAA (the main serotonin metabolite) was undertaken on 10 parkinsonian patients. The determinations were made before and after l-DOPA therapy, when a satisfactory clinical status was achieved. The results obtained clearly demonstrate that a large increase of HVA was found in CSF during l-DOPA therapy, but no relationship was found between HVA levels and clinical improvement. A decrease of 5-HIAA in CSF during l-DOPA treatment was found.These results are discussed in the light of a relationship between dopamine and serotonin during l-DOPA therapy.