Chronic adult cerebral infarction studied by phosphorus NMR spectroscopy

Spatially localized phosphorus (P-31) nuclear magnetic resonance (NMR) spectra were recorded in vivo from the brains of nine healthy adults and of four adult patients examined 10 weeks to 7 years following cerebral infarction. Spectra from the healthy adult subjects showed reduced inorganic phosphate (Pi) and phosphoester resonances compared with earlier such measurements in infants. Spectra from subjects with chronic cerebral infarction exhibited no significant differences in the ratios of high-energy phosphate metabolites, Pi, or pH compared with the spectra of the healthy adults, although decreases of up to about 40% in the total P-31 NMR signal from infarcted tissue were noted. These results are consistent with a reduction in the number of metabolically active brain cells and/or a decrease in cellular functional activity in chronic infarction. Phosphorus metabolite ratios do not appear to be a sensitive indicator of abnormal energy reserve in chronic brain infarction in adults.