PROTON MAGNETIC-RESONANCE SPECTROSCOPY - THE NEW GOLD STANDARD FOR DIAGNOSIS OF CLINICAL AND SUBCLINICAL HEPATIC-ENCEPHALOPATHY

Human hepatic encephalopathy (HE) is identified by a new noninvasive t est, proton magnetic resonance spectroscopy (H-1 MRS) applied to the b rain in a few minutes. Chemical changes identified by H-1 MRS are elev ated glutamine, decreased choline and decreased myoinositol. The speci fic association with HE is proven by clinical studies in patients with cirrhosis, overt and subclinical HE, by the appearance of the same ch anges after transjugular intrahepatic portasystemic shunt, and by thei r complete reversal by liver transplantation. The importance of the ne w marker, myoinositol, may lie in its role as an osmolyte regulating c ell volume in the astrocytes. Other roles are also postulated. Progres s in the management of both HE and subclinical hepatic encephalopathy may depend upon finding means, short of liver transplantation, which w ill restore cerebral choline and myoinositol. The finding of identical changes in experimental animals simplifies the search.