Abnormal baseline brain activity in low-grade hepatic encephalopathy: a resting-state fMRI study

Area of Science:

• Neuroimaging
• Neurology
• Hepatology

Background:

• Low-grade hepatic encephalopathy (HE) is a common neuropsychiatric complication of liver cirrhosis.
• Resting-state fMRI is a valuable tool for detecting spontaneous neuronal activity alterations in neuropsychiatric diseases.
• Research on brain activity in low-grade HE using fMRI is limited.

Purpose of the Study:

• To investigate spontaneous brain activity in patients with low-grade HE using resting-state fMRI.
• To compare brain activity patterns between healthy controls, cirrhotic patients without HE, and cirrhotic patients with low-grade HE.
• To explore the relationship between altered brain activity and neurocognitive performance in low-grade HE.

Main Methods:

• Resting-state fMRI was performed on 19 healthy controls, 18 cirrhotic patients without HE, and 22 cirrhotic patients with low-grade HE.
• Amplitude of low-frequency fluctuations (ALFF) was computed to quantify spontaneous neuronal activity.
• Statistical analyses identified regions with significant ALFF differences among the groups.

Main Results:

• Patients with low-grade HE exhibited decreased ALFF in the precuneus, cuneus, visual cortex, and left cerebellum posterior lobe compared to controls or patients without HE.
• Compared to controls, low-grade HE patients showed increased ALFF in various cortical and subcortical regions, including the cingulate cortex, frontal lobe, insula, and lentiform nucleus.
• ALFF changes in low-grade HE patients correlated with poorer neurocognitive performances.

Conclusions:

• Baseline brain activity is aberrant in low-grade HE, characterized by both decreased and increased ALFF in distinct brain regions.
• These brain activity alterations may contribute to the neurological pathophysiology of HE.
• Resting-state fMRI can detect neurophysiological changes associated with low-grade HE and its cognitive impact.