Subclinical hepatic encephalopathy: proton MR spectroscopic abnormalities.

Abstract

To determine whether hydrogen-1 magnetic resonance (MR) spectroscopy of the brain allows detection of subclinical hepatic encephalopathy (SCHE). In a double-blind study, overt hepatic encephalopathy (HE) and SCHE (defined with clinical and neuropsychiatric tests) were compared by means of H-1 MR spectroscopic criteria--reduction in cerebral myo-inositol (< 2 standard deviations [SDs] from normal) and choline (< 2 SDs from normal) with or without increased cerebral glutamine (> 1 SD from normal)--in 20 patients with cirrhosis. Concordance between MR spectroscopic and neuropsychiatric test results was 94% (kappa = 0.84). MR spectroscopy allowed diagnosis of SCHE in nine of nine patients (100%) and of HE in seven of eight (88%). Myo-inositol depletion alone had 80%-85% sensitivity for detection of HE and SCHE. H-1 MR spectroscopy allows accurate diagnosis of SCHE, and the results suggest an important role for myo-inositol in psychomotor and visuopractic functions.