Extrastriatal monoamine neuron function in Parkinson's disease: an 18F-dopa PET study

Neurobiol Dis. 2008 Mar;29(3):381-90. doi: 10.1016/j.nbd.2007.09.004. Epub 2007 Sep 26.


The early motor manifestations of Parkinson's disease (PD) reflect degeneration of nigrostriatal dopamine neurons projecting to the caudal putamen. However, extrastriatal dopamine and other monoamine systems are also involved, particularly in later disease. We used (18)F-dopa PET in a cross-sectional study to characterize extrastriatal monoamine neuronal dysfunction in PD. 16 Controls and 41 patients underwent investigation. We found that (18)F-dopa uptake was decreased in cortical motor areas, particularly the motor cortex, even in early disease. Frontal association areas were also affected in later disease but limbic areas were spared except for hypothalamus. The substantia nigra, midbrain raphe and locus coeruleus showed normal or increased (18)F-dopa uptake until PD was advanced, indicating compensatory responses in intact monoamine neuron perikarya. The red nucleus, subthalamus, ventral thalamus and pineal gland were also eventually involved. These findings provide a further basis for understanding the complex pathophysiology of PD in vivo and complement pathological studies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biogenic Monoamines / metabolism
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / metabolism
  • Cross-Sectional Studies
  • Dihydroxyphenylalanine* / metabolism
  • Dopamine / metabolism*
  • Fluorine Radioisotopes
  • Humans
  • Middle Aged
  • Neurons / diagnostic imaging*
  • Neurons / physiology
  • Parkinson Disease / diagnostic imaging*
  • Parkinson Disease / metabolism*
  • Positron-Emission Tomography / methods*


  • Biogenic Monoamines
  • Fluorine Radioisotopes
  • Dihydroxyphenylalanine
  • Dopamine