High resolution proton nuclear magnetic resonance studies of human cerebrospinal fluid

Abstract

One- and two-dimensional (correlated shift spectroscopy) high resolution proton n.m.r. spectra of human cerebrospinal fluid (CSF) are reported. The merits of water suppression by freeze drying or irradiation, and spectral simplification by spin-echo methods, are discussed. Well-resolved resonances for a range of low molecular weight metabolites such as lactate, 3-D-hydroxybutyrate, alanine, acetate, citrate, glucose, valine and formate were observed. Resonances for glutamine were observed only from freeze dried samples. Concentrations determined by n.m.r. were in reasonable agreement with those from conventional methods. The n.m.r. spectra of CSF were related to the clinical conditions of the subjects. No resonances for citrate were present in spectra of CSF from subjects (three infants) with bacterial meningitis; high lactate and lowered glucose levels were observed. Strong resonances for glucose and glycine were observed for mildly diabetic subjects. Both the aromatic and the aliphatic regions of the CSF spectra from subjects suffering from liver failure contained distinctive features characteristic for hepatic coma: Intense resonances for lactate, alanine, valine, methionine, tyrosine, phenylalanine and histidine. In some cases guanine was also present, which does not appear to have been reported previously. The two-dimensional spectrum suggested the presence of abnormally high levels of a number of endogenous metabolites. Such assignments were not possible using one-dimensional spectra alone because of signal overlap.

Near-Infrared Spectroscopy-Derived Tissue Oxygen Saturation in Battlefield Injuries: A Case Series Report

“…More than hundred have been identified based on NMR spectroscopy in CSF from patients with various neurological, metabolic and other nonneurological diseases [29], the most abundant being glucose and lactate, with lesser amounts of acetate, citrate, formate, 3-hydroxyl-butyrate, alanine, valine and glutamine [30]. The major metabolites in CSF samples from humans without infections or other apparent diseases are similar to those in healthy rats as observed in the present study (Figure 2).…”

Increased plasma phenylacetic acid in patients with end-stage renal failure inhibits iNOS expression

“…The spectral width was 5 kHz. Using these conditions, spectra were fully T 1 relaxed, and, for sharp resonances, T 2 relaxation during the period 3t was not observed (28). The water resonance at 4.8 parts per million (ppm) was suppressed by presaturation during relaxation and mixing time with a 90-degree sequence (d 1 -90°-d 0 -90°-d 9 -90°-free induction decay) (29).…”

Expanding lacunae causing triventricular hydrocephalus

“…[6] In both of our patients, we included expanding lacunae and surrounding normal-appearing brain parenchyma in the region of interest for proton spectroscopy. The increased levels of lactate without changes in the ratios of NAA/Cr, Cho/Cr, and mI/Cr are consistent with the increased content of normal CSF within the expanding lacunae [3,16,23] and reflect the paucity of tissue alterations, if any, in the surrounding parenchyma.…”