2006 Fiscal Year Final Research Report Summary
Mechanism of hepatic encephalopathy: special reference to cognitive functions of cerebral cortex
| Project/Area Number |
16590621
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Gastroenterology
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| Research Institution | Iwate Medical University |
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Principal Investigator |
KATO Akinobu Iwate Med. Univ., First Dept. Int. Med., Associate Prof., 医学部, 助教授 (50177424)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Yuuki Iwate Med. Univ., First Dept. Int. Med. Res., Associate, 医学部, 助手 (00405771)
INOUE Takashi Iwate Med. Univ., Neurosurgery, Lecturer, 医学部, 講師 (70326651)
SUZUKI Kazuyuki Iwate Med. Univ., First Dept. Int. Med., Professor, 医学部, 教授 (00137499)
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| Project Period (FY) |
2004 – 2006
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| Keywords | subclinical hepatic encephalopathy / liver cirrhosis / computer-aided quantitative neuropsychiatric functional tests / magnetic resonance spectroscopy / brain glutamine / brain gliutamate / blood ammonia |
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| Research Abstract |
We developed an easily conducted computoer-aided quantitative neuropsychiatric function test system for use in routine medical practice. We established normal values in healthy Japanese subjects and determined differences between healthy persons and liver cirrhosis patients without clinical encephalopathy in a multi-center clinical trial. The test system consist of eight tests : number connection test A and B, a figure position test, a digit symbol test, a block design test, and reaction test A, B and C. When the cut-off value was set at the 10^<th>/90^<th> percentile of the results in healthy subjects, the results of each of the 8 tests were abnornmal in about 25% of cirrhotic patients, and at least 1 of the 8 tests gave values greater than the 10^<th>/90^<th> percentile cut-off value in 58.2% of the 292 liver cirrhosis patients. Subclinical hepatic encephalopathy patients were thought to be included in thses 58.2% of patients. The developed test makes it possible to quantitatively as
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sess neuropsychiatric function and the results obtained can be use as a basis for the diagnosis of subclinical hepatic encephalopathy
Magnetic resonance spectroscopic (MRS) studies have revealed abnormal metabolism in the brain of the patients with liver cirrhosis, including an invrease in total brain glutamine (Gin) and glutamate (Glu) levels (Glx). However, with conventional MRS techniques, it was difficult to separate the Glx signals. Using a high-magnetic field MR equipment and a newly developed data processing method, we attempted to separate the Glx signals on an MRS. Twenty-three patients with liver cirrhosis and 11healthy adults were enrolled in this study. After designating a region of interest in the occipital lobe gray matter of each subjects, 1H(proton)-MRS was performed using 3.0-tesla MR equipment. MRS conducted using the 3.0-tesla allowed Gln signals in the brain to be distinguished from the Glx signals. The brain signal intensity of Gln was found to be significantly higher in the liver cirrhosis group (0.658±0.23) than in the control group (0.473 ±0.08) (p<0.05). Neither the Glu nor Gln signals intensity showed any correlation with the blood ammonia level. High-magnetic field MRS allowed us to separate the Glx signals in the brain and revealed that the increase in the tital brain Glu and Gln levels in patients is solely attributable to an increase in the level of Gln. Less
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