The effects of L-threo-3,4-dihydroxyphenylserine on the total norepinephrine and dopamine concentrations in the cerebrospinal fluid and freezing gait in parkinsonian patients

J Neural Transm Park Dis Dement Sect. 1993;5(1):27-34. doi: 10.1007/BF02260912.


We studied the effects of L-threo-DOPS (L-DOPS) on the concentrations of total (conjugated and unconjugated) dopamine (DA) and norepinephrine (NE) in the cerebrospinal fluid (CSF) of parkinsonian patients with freezing phenomenon. The NE concentration increased remarkably and dose-dependently after administration of L-DOPS in both L-dopa/carbidopa-pretreated and untreated patients. The DA concentration also increased mildly but significantly in L-dopa/carbidopa-untreated patients. Freezing phenomenon improved in 6 out of 8 patients at Hoehn and Yahr's stage III, and 1 out of 5 patients at stage IV. These results indicate that L-DOPS administration increases the NE concentration dose-dependently, and is effective for freezing of gait of moderate severity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Carbidopa / pharmacology
  • Carbidopa / therapeutic use
  • Dopamine / cerebrospinal fluid*
  • Dose-Response Relationship, Drug
  • Droxidopa / pharmacology*
  • Female
  • Gait / drug effects*
  • Humans
  • Levodopa / pharmacology
  • Levodopa / therapeutic use
  • Male
  • Middle Aged
  • Norepinephrine / cerebrospinal fluid*
  • Parkinson Disease / cerebrospinal fluid*
  • Parkinson Disease / drug therapy
  • Parkinson Disease / physiopathology


  • Levodopa
  • Droxidopa
  • Carbidopa
  • Dopamine
  • Norepinephrine