HYPOXIC ENCEPHALOPATHY AFTER NEAR-DROWNING STUDIED BY QUANTITATIVE H-1-MAGNETIC RESONANCE SPECTROSCOPY - METABOLIC CHANGES AND THEIR PROGNOSTIC VALUE

Early prediction of outcome after global hypoxia of the brain requires accurate determination of the nature and extent of neurological injur y and is cardinal for patient management, Cerebral metabolites of gray and white matter were determined sequentially after near-drowning usi ng quantitative H-1 nuclear magnetic resonance spectroscopy (MRS) in 1 6 children. Significant metabolite abnormalities were demonstrated in all patients compared with their age-matched normal controls, Severity of brain damage was quantified from metabolite concentrations and rat ios, Loss of N-acetylaspartate, a putative neuronal marker, from gray matter preceded that observed in white matter and was more severe. Tot al creatine decreased, while lactate and glutamine/glutamate concentra tions increased. Changes progressed with time after injury. A spectros copic prognosis index distinguished between good outcome (n = 5) and p oor outcome (n = 11)with one false negative (bad outcome after borderl ine MRS result) and no false positive results (100% specificity), The distinction was made with 90% sensitivity early (after 48 h) and becam e 100% later (by days 3 and 4). This compared with 50-75% specificity and 70-100% sensitivity based upon single clinical criteria. MRS perfo rmed sequentially in occipital gray matter provides useful objective i nformation which can significantly enhance the ability to establish pr ognosis after near-drowning.