Imaging of neuroinflammation in parkinsonian syndromes with positron emission tomography.

Microglial activation is a key aspect of the neuroinflammatory process in neurodegenerative disorders including idiopathic and atypical parkinsonian disorders. Using positron emission tomography, it has become possible to image this phenomenon in vivo and over the last years patterns of microglia activation corresponding well known distribution of neuropathologic changes in these disorders have successfully been demonstrated using this technique. It has also been possible to measure the effects of interventions aimed at suppressing microglia activation as part interventional trials. Current research aims at evaluating positron emission tomography tracers for microglial activation with more favorable properties than the prototypical [(11)C]-(R)-PK11195, as well as developing tracers targeting additional parameters of the neuroinflammatory process like astroglial function or the cannabinoid receptor type 2.