In addition to monitoring clinical features, we had also chosen to test physiologic effects of alpha-lipoic acid/L-acetyl carnitine in our PSP subjects using two biomarkers that provide measures of mitochondrial function and oxidative stress. This was particularly important, since both supplements may act by multiple mechanisms. 1H MRSI is a technique that provides insight into the metabolism of several endogenous brain compounds, most notably N-acetyl-L-aspartate (NAA), choline-containing compounds (Cho), and creatine and phosphocreatine (Cr). A number of studies of mitochondrial function had firmly established the utility of 1H MRSI in probing potential mitochondrial energy metabolism dysfunction. 31P MRSI provided complementary information to probe in vivo mitochondrial energy metabolism and tissue energetics. In addition, we proposed using markers of oxidative damage (including 8-hydroxydeoxyguanosine) as well as metabolomic analysis to test a composite panel of quantitative measures in plasma. We used an established metabolomic platform that has proven to identify specific combinations of metabolites differing between neurodegenerative disease states (including Parkinson's disease, Huntington's disease) and healthy controls. Our overall aim was to generate an "oxidative biomarker" and "metabolomic read-out" of the peripheral biochemical effects of alpha-lipoic acid/L-acetyl carnitine in PSP.