Spectroscopy of human plasma for diagnosis of idiopathic Parkinson's disease.

BACKGROUND: No established chemical biomarkers of idiopathic Parkinson's disease (PD) currently exist. Augmented oxidative stress (OS) has been implicated in both neural and peripheral PD tissues. METHODS: In this study, Raman scattering and near-infrared spectroscopy were used to detect and quantify oxidative substrate modifications in blood plasma samples from PD and normal elderly control (NEC) subjects. RESULTS: Hypothesis-driven preselection of OS-sensitive bandwidths distinguished PD from NEC subjects with approximately 75% sensitivity and specificity using both complementary spectroscopic techniques. CONCLUSION: Biospectroscopy of plasma may provide a rapid, minimally invasive and inexpensive chemical biomarker of idiopathic PD.