Reduced Cortical Complexity in Cirrhotic Patients with Minimal Hepatic Encephalopathy

Abstract

Purpose. Gray matter volume loss, regional cortical thinning, and local gyrification index alteration have been documented in minimal hepatic encephalopathy (MHE). Fractal dimension (FD), another morphological parameter, has been widely used to describe structural complexity alterations in neurological or psychiatric disease. Here, we conducted the first study to investigate FD alterations in MHE. Methods and Materials. We performed high-resolution structural magnetic resonance imaging on cirrhotic patients with MHE (n=20) and healthy controls (n=21). We evaluated their cognitive performance using the psychometric hepatic encephalopathy score (PHES). The regional FD value was calculated by Computational Anatomy Toolbox (CAT12) and compared between groups. We further estimated the association between patients’ cognitive performance and FD values. Results. MHE patients presented significantly decreased FD values in the left precuneus, left supramarginal gyrus, right caudal anterior cingulate cortex, right isthmus cingulate cortex, right insula, bilateral pericalcarine cortex, and bilateral paracentral cortex compared to normal controls. In addition, the FD values in the right isthmus cingulate cortex and right insula were shown to be positively correlated with patients’ cognitive performance. Conclusion. Aberrant cortical complexity is an additional characteristic of MHE, and FD analysis may provide novel insight into the neurobiological basis of cognitive dysfunction in MHE.

Mental Fatigue Has Great Impact on the Fractal Dimension of Brain Functional Network

“…Fractal has been found to widely exist in nature [ 12 ]. Since the fractal theory was revealed, it has been widely used in biomedical signal analysis, such as EEG [ 13 ], fMRI (functional magnetic resonance imaging) [ 14 ], and MRI [ 15 ]. Naturally, a scientific question arises: does the brain functional network have fractal feature?…”

Cortical complexity estimation using fractal dimension: A systematic review of the literature on clinical and nonclinical samples

“…Only one study evaluated FD in patients with minimal hepatic encephalopathy (Q. F. Chen, Zhang, et al, 2020). The authors estimated FD using spherical harmonic reconstruction and observed reduced FD values in patients with minimal hepatic encephalopathy, compared with controls, in the bilateral pericalcarine cortex, bilateral paracentral cortex, left precuneus, left supramarginal gyrus, right anterior caudal cingulate cortex, right isthmus cingulate cortex and right insula.…”

Cortical Complexity Alterations in Motor Subtypes of Parkinson's Disease: A Surface-Based Morphometry Analysis of Fractal Dimension

“…FD has been extensively used to investigate alterations in the morphological cerebral pattern in various conditions and neurological disorders, such as amyotrophic lateral sclerosis [29], minimal hepatic encephalopathy [30], anorexia nervosa [31], multiple sclerosis [32], spinocerebellar ataxia [33], Alzheimer's disease [34], and dementia spectrum disorders [35]. There are a few studies that have investigated FD changes in PD patients.…”