Application of 18F-FDOPA PET and Magnetic Resonance Spectroscopy (MRS) With HCV and PD

The objective of this study is to investigate the evidence of dopaminergic toxicity causing by HCV infection using 18F-FDOPA PET and MRS as imaging biomarkers.

Parkinson's disease (PD) is the most common neurodegenerative disorder after Alzheimer's disease. It is characterized by degeneration of the dopaminergic neurons in substantia nigra and striatum, even before the clinical symptoms develop. Although the pathogenesis is still unclear, some viruses have been shown to be associated with acute or chronic parkinsonism. Recent studies have found that Hepatitis C virus (HCV) can replicate in the central nervous system, suggesting a possible link between PD and HCV. At the population and epidemiology level, the HCV infection and PD are strongly associated. At the molecular level, both HCV and PD have in common the overexpression of inflammatory biomarkers. Neuronal toxicity induced by HCV was also demonstrated. The positive association between HCV infection and PD has clinical implications for high endemic HCV areas, including Taiwan. 18F-FDOPA, an analog to L-DOPA, has been used as a positron-emitting compound for PET examination of patients affected by PD. It has been shown that putamen 18F-FDOPA uptakes are reduced by at least 35% at onset of symptoms, making the 18F-FDOPA PET as an imaging biomarker for detecting subclinical and preclinical parkinsonism. Earlier imaging study using magnetic resonance spectroscopy (MRS) to investigate cerebral effect of HCV also showed that chronic HCV infection had elevated choline/creatine ratios, a biomarker indicating inflammatory and infective conditions, in the basal ganglia and white matter. The objective of this study is to investigate the evidence of dopaminergic toxicity causing by HCV infection using 18F-FDOPA PET and MRS as imaging biomarkers.