Regional variation in brain lactate in Leigh syndrome by localized 1H magnetic resonance spectroscopy. Localized water-suppressed 1H magnetic resonance spectroscopy was performed in an 11-month-old infant with Leigh syndrome. Spectra obtained from the basal ganglia, occipital cortex, and brainstem showed elevations in lactate, which were most pronounced in regions where abnormalities were seen with routine T2-weighted magnetic resonance imaging. This approach has allowed us to examine metabolism in brain tissue directly and noninvasively, and may provide a sensitive means for evaluating metabolic disease and the response to therapy in the brain. 