Proton spectroscopy of brain glutamine in acute liver failure

✍ Scribed by Associate Professor James R. McConnell; Dean L. Antonson; Chin Siong Ong; Wei-Kom Chu; Ira J. Fox; Thomas G. Heffron; Alan N. Langnas; Byers W. Shaw Jr.

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 571 KB
• Volume: 22
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840220111

✦ Synopsis

Evidence indicates that the accumulation of glutamine in the brain plays an important role in the pathogenesis and severity of the encephalopathy of acute liver failure (ALF). This study uses in uiuo proton magnetic resonance spectroscopy ('H MRS) to assess brain glutamine (GLN) in five cases of acute liver failure. The findings are consistent with prior investigations and suggest that the alpha 'H of the GLN molecule can be used for noninvasive spectroscopic quantitation of brain GLN in patients with ALF. (HEPATOLOGY 1995;22:69-74.)

The neurologic manifestations of encephalopathy in patients with acute liver failure (ALF) can progress from mild confusion to stupor and coma. Death may result from brain edema in ALF.l,' The pathogenesis of the progressive encephalopathy and brain edema is unknown, but evidence suggests that increased brain glutamine (GLN) plays an important role.

An in viuo microdialysis study of the brain found significantly increased GLN in the cerebral cortex and in the extracellular fluid of the brain in experimental ALF.3 Research models of ALF have demonstrated that increased brain GLN is also associated with the development of brain edema.*-' Inhibition of glutamine synthetase, an enzyme in astrocytes that converts ammonia and glutamate (GLU) to GLN, can prevent the development of brain edema in experimental ALF. '-16 Investigators in 1955 demonstrated that GLN concentration was elevated in the cerebrospinal fluid of patients in hepatic coma, and later clinical studies have suggested that increased concentration of cerebrospinal fluid GLN correlates with the severity of hepatic encephalopathy (HE).l7-l'

In vivo proton magnetic resonance spectroscopy ('H