STANDARDIZED METHOD FOR HIGH-RESOLUTION H-1-NMR OF CEREBROSPINAL-FLUID

This study describes a standardized method for recording single-pulse H-1-nuclear magnetic resonance (H-1-NMR) spectra from cerebrospinal fl uid (CSF). Quantitative data for alanine, valine, threonine, and lacti c acid correlated well with data obtained with conventional techniques . The pH of the samples is important for the reproducibility of the ch emical shift of resonances, and should be standardized to improve reco gnition and assignment of resonances. A database of resonances from va rious metabolites is presented. Fifty compounds could be identified in CSF, 15 of which had not been observed earlier in NMR studies of CSF. We describe for the first time in the literature, to our knowledge, 3 -hydroxyisovaleric acid as a regular component of many CSF samples. As examples of the diagnostic power of the technique, spectra are shown of CSF from patients with three different inborn errors of metabolism. We found high concentrations of N-acetylaspartic acid, citric acid, a nd succinic acid in CSF from a patient with Canavan disease. This is i ndirect evidence for the existence of a carrier mechanism that is shar ed by these di- and tricarboxylic acids.