Study On Subclinical Hepatic Encephalopathy Attention Network Ethology And Functional Imagiology

Objects This research applies clinical scale, the attention network test (ANT) software package, the technology of Function Magnetic Resonance Imaging (fMRI), and functional neuroimaging, to investigate the brain function state and action mode of the attention net execution control part of the patients with subclinical hepatic encephalopathy (SHE) and explain the potential brain function mechanism.Methods Record 16 cases of liver cirrhosis from January 2008 to December 2009 in The First Affiliated Hospital of Guangxi Medical University, at the same time 16 healthy controls are selected. Every subject takes mini-mental state examination (MMSE), and block design, digit symbol of China's revised Wechsler Adult Intelligence Scale to evaluate his/her intelligence and operative ability. Testing the attention function praxiology combines with the ANT software package and recording the reaction time. Screen 10 patients with SHE from the 16 cases of liver cirrhosis, and according to the age, sex and the level of education of the 10 patients 10 healthy controls selected as a group for research. Adopt classic ANT as stimulus task and event-related block FMRI scanning and the data of FMRI is analysed by statistical parametric mapping software (SPM2).Results (1) Compared with healthy controls, the average ANT reaction time of the group of patients is slower (control group:597.64±126.36 ms, patients:783.60±289.62 ms), patients group has more errors than the control group in ANT (4.8±2.0, control group:1.9±1.0). (2) The scanning of MRI shows that 7 of the 10 cases patients with SHE seen the high symmetry signal shadow in T1WI globus pallidus, and 3 of the 7 cases the high symmetry signals are seen (caused by the precipitation of the manganese metal) in cerebral peduncle and substantia nigra of midbrain. (3) Execution control function magnetic resonance of healthy group shows the laterality of right hemisphere of brain activation locates in right hemisphere anterior cingutate, prefrontal lobe and parietal lobe and other encephalic regions. Compared with healthy controls, the execution control net activation level of the patients with SHE is lower:the attention net system brain activation zone which are near brain midline areas in right prefrontal lobe and anterior cingulated activate less apparently.Conclusion The result of this research shows that the hypofunctions in the anterior cingulate, prefrontal lobe and parietal lobe of the patients with subclinical hepatic encephalopathy (SHE), and they have attention net execution function lesion in other words they have damage in attention function. It is in line with the ANT ethology. Manganese metal intoxation probably is one of the causes of the lesion of the attention execution control net.